CA2246070A1 - Undeformed lock nut with slot - Google Patents
Undeformed lock nut with slot Download PDFInfo
- Publication number
- CA2246070A1 CA2246070A1 CA002246070A CA2246070A CA2246070A1 CA 2246070 A1 CA2246070 A1 CA 2246070A1 CA 002246070 A CA002246070 A CA 002246070A CA 2246070 A CA2246070 A CA 2246070A CA 2246070 A1 CA2246070 A1 CA 2246070A1
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- Canada
- Prior art keywords
- lock nut
- nut
- body member
- bottom end
- deformable
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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- 238000009434 installation Methods 0.000 claims abstract description 37
- 230000002829 reductive effect Effects 0.000 claims abstract description 13
- 238000004519 manufacturing process Methods 0.000 description 7
- 230000014759 maintenance of location Effects 0.000 description 4
- 230000036961 partial effect Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 2
- 230000003292 diminished effect Effects 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 238000004513 sizing Methods 0.000 description 2
- 240000006829 Ficus sundaica Species 0.000 description 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B39/00—Locking of screws, bolts or nuts
- F16B39/22—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening
- F16B39/28—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening by special members on, or shape of, the nut or bolt
- F16B39/284—Locking by means of elastic deformation
- F16B39/286—Locking by means of elastic deformation caused by saw cuts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
- F16B39/00—Locking of screws, bolts or nuts
- F16B39/22—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening
- F16B39/24—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening by means of washers, spring washers, or resilient plates that lock against the object
- F16B39/26—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening by means of washers, spring washers, or resilient plates that lock against the object with spring washers fastened to the nut or bolt-head
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Bolts, Nuts, And Washers (AREA)
- Dowels (AREA)
Abstract
A lock nut threadably engageable and lockingly retainable about a threaded shaft extending through a workpiece, the lock nut having at least one deformable slot disposed on a side portion thereof and disposed transversely relative to the lock nut bore axis, the lock nut also having a nut deforming member protruding from a bottom end thereof, wherein at least a portion of the nut deforming member is in substantial axial alignment with the deformable slot. The lock nut is undeformed prior to installation thereof about the threaded shaft. The nut deforming member is engageable with the workpiece to deform the lock nut upon threadably installing the lock nut about the threaded shaft, thereby retaining the lock nut thereabout, whereby the lock nut has a relatively consistent torque performance with reduced statistical spread over several installation and removal cycles of the nut about the threaded shaft.
The nut deforming member is an annular portion of the skirt disposed peripherally on the bottom end of the lock nut, which may have a substantially countersunk surface.
The lock nut may alternatively include a spring washer rotatably coupled thereto.
The nut deforming member is an annular portion of the skirt disposed peripherally on the bottom end of the lock nut, which may have a substantially countersunk surface.
The lock nut may alternatively include a spring washer rotatably coupled thereto.
Description
Atty. Docket No. ~147 UNDEFC)RMED LOCK NUT WITI~ SLOT
BACKGROUND OF THE INVENTION
The invention re]ates generally to lock nuts t]~readably engageable and lockingly retainable about a threaded s]laft, and more particularly to lock nuts which are undeformed prior to installation, and lock nuts l~aving improved torque performance, while provil:~ing extremely lo~ "filst on" torques, including relatively consistent torque per~ormance with reduced statistical spread over several installation and removal cycles.
Lock nuts have many configurations and are used widely in industry.
U.S. Patent No. 2,142,~19 entitled "Self Gripping Device" issued on 3 January 1939 to Olson and coumlonly assigned herewith, for exalnple, discloses a loc~ing nut having diametrically opposed slots disposed transversely therein to form yieldable sections, which are deflected axially to distort a portion of the tllreaded bore by helical disalignrnent thereof along the yieldable sections, prior to installation thereof, thereby providing a balanced frictional grip on a threaded sllaft subsequently disposed througl the threaded bore of the lock nut.
U.S. Paeent No. 3,659,491 entitled "Rotatable Nut ~nd Washer Assembly"
issued on 2 May 1972 to Duffy et al discloses a lock nut forll1ed of a threaded inner barrel coupled by a web to a hexagonally shaped o-lter barrel having a radially extending peripheral skirt, which is formed as a llnitaly nut melllber. Tlle nut of U.S.
John P. PATIERSO~I, Jr. et al. Atty. Docket No. 8147 "Undeforrned Lock Nut With Slot"
Patent No. 3,659,491 is rotatably coupled to a frusto-conical spring washer, which forms an assembly, wherein the spring washer is flattenable betveen the nut and a workpiece, to provide a reverse axial tension on the nut and a radially inwardlydirected compressive force on the inner barrel, which locks the nut about a threaded S shaft. l~he spring washer in U.S. Patent No. 3,659,491 becomes rotationally fixed relative to the workpiece, thereby reducing the torque required to install the lock nut about the shaft and thereby also reducing damage to the surface of the workpiece, which otherwise occurs when the washer is rotationally fixed relative to the rlut. The lock nut of U.S. ~atent No. 3,659,491 however is relatively expensive to manufacture, particularly the unitaly nut portion, which is fabricated from sheet metal.
Generally, prior art lock nut retention performance is diminished substantially upon removal of the nut from the threaded shaft. In lock nuts of the type disclosed in U.S. Patent No. 2,142,819 discussed above, the diminished retentionperforrnance results from a tendency of the s]ots to widen after the lock nut isdisposed about the shaft during tlle first installation and subsequent first removal tllerefrom. This adverse effect on prior art lock nut retention performance is particularly significant after the first installation and removal cycle, and continues to worsen as the lock nut is subject to repeated cycles of installation and removal, which commonly occurs in applications where the nut lnust be removed and reinstalled for ~0 service and maintenance.
FIG. 9 of tlle present patent application illustrates graphically the torque performance of prior loclc nuts over several installation and removal cycles generally, and more particularly illustrates tlle relatively large torque required for the first installation, or first on, in comparison to the substantially reduced torque required for the first removal, or first off, whereill the torque performance continues to diminish, tho-lgh at a lesser rate, with increasing numbers of on and off cycles. FIG. 9 also illustrates the relatively incollsistent torque perforlllance of prior art lock nuts, particularly over tlle interval between tlle "1 0~" througll tlle "3 OFF" wllereafter tlle torque performance is more consistent over tlle intelval bet~veen the "3 Ol:~F" and the John P. PATI ERSON~ Jr. et al Atty. Docket No. 8147 "Undeforrned Lock Nut Wilh Slot"
"S OF~". FIG. 9 i]lustrates further the tendency of prior art lock nut torque per~ormance not to comphJ with an industry established torque specification as it decreases below the SPEC curve somewhere between the "2 OFF" and "3 OF~", which often results from the relatively large statisiical spread associated with the torque performance of prior art lock nuts.
The copending U.S. Application No. 08l628,923 entitled "Prevailing Torque Nut" discloses a novel lock nut configuration having relatively consistent torque performance and reduced statistical spread over several repeated cycles of nut installation and nut removzl about a threaded shaftl which is a remarkable improvement over prior art lock nuts. The copending U.S. Application No. 08/628,982 entitled "Method for Sizing a Lock Nut" discloses a method of manufacturing a lock nut that includes a step of threading an enlarged sizing tool through a deformedportion of a lock nut threaded bore during the manufacture thereof and prior to actual use of the lock nut, which further improves the torque periormance thereof. Moreparticularly, the sized lock nut of IJ.S. Application No. 08l628,923 has among other advantages a relatively more consistent torque performarlce over several installation and removal cycles, including a reduced first on torque and reduced statistical spread.
The tllreaded bore portions of these lock nuts however are deformed prior to installation.
T}le present invention is drawn to improved lock n-lts tllat overcome problerns in the prior art, and rnore pa1ticularly to lock nuts having further improvements in torque performance, including greater consistency of torque performance, substantially reduced first on torque, and reduced statistical spread.
It is a more particular object of the present invention to provide a novel lock nut threadably engageable and lockingly retainable about a tllreaded shaft extending through a workpiece, the lock nut having at least one deforrnable slotdisposed on a side portion tllereof and disposed transversely relative to the lock nut bore axis, the lock nut also llaving a nut deforming member protruding from a bottom end tllereof, whereirl at least a portion of the nut deforming member is in sul~stantial John P. PAl~ERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
axial alignment with the deformable slot. Notably, the lock nut is undeformed prior to installation thereof about the threaded shaft. The nut deforming member is howeYer engageable with the workpiece to deform the lock nut upon threadably installing the lock nut about the threaded shaft, thereby retaining the lock nutthereabout, whereby the lock nut has a relatively consistent torque performance with reduced statistical spread over several installation and removal cycles of the nut about the threaded shaft.
It is also an object of the invention to provide a novel lock nut of the more particular configuration described a~ove, wherein the lower portion of the lock nut includes a skirt extending outwardly beyond the side portion thereof, and wherein the mlt deforming member is an annular portion of the skirt disposed peripherally on the lower end thereof, wherein a bottom portiorl of the lock nut has a substantially concaved or countersunk surface.
It is another object of the invention to provide a novel lock nut of the more particular configurations described above, wherein the lock nut includes a plurality of at least two deformable slots disposed on side portions thereof and a corresponding plurality of nut deforming members disposed on the bottom end of the body member in substantial axial alignment with the corresponding deformable slot.
In one embodiment, the deformable slots are disposed substantially transversely to the bore axis and substantially symmetrically thereabout, and in anotller embodiment one or more of the plurality of deformable slots is offset axially along the bore axis relative to the other deformable slots.
It is a furthl r object of the invention to provide a novel lock nut of the more particular configurations described above, wllerein the lock nut includes asubstantially conical spring washer rotatably coul)led to the lower portion of the body member. A sloping upper sllrface of the spring wasller slopes away from the bottom end of the body member and accommodates t]le one or more nut deforming members therebetween, wllereby the nut deforming members are engageable with the upper surface of tlle spring wasller to deform the body nlelllber upon clamping and flattening John P. PAl rERSON, Jr. et al. Atty. Docket No. 8147 "Undeforrned Lock Nut With Slot"
the spring washer between the bottom end of the body member and a workpiece.
These and other objects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the I~vention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps arereferenced by corresponding numerals and indicators.
BRIEF DESCRIPTION OF TIIE I~ AWINGS
FIG. 1 is a side elevational view of a lock nut according to a first exemplary embodiment of the invention.
FIG. 2 is a lop plan view of the lock nut of FIG. 1.
FIG. 3 is a sectional view along lines a - a of FIG. 2.
FIG. 4 is a side elevational view of a lock nut according to a second exemplary embodiment oi the invention.
FIG. 5 is a lop plan view of the lock nut of FIG. 4.
FIG. 6a is a ~partial sectional side elevational view of a lock nut according to a third exemplary embodin1ent of the invention.
FIG. 6b is a partial sectional view along lines b-b of FIG. 6a.
FIG. 7 is a side elevational view of a lock nut according to the present invention disposed al~out a tllreaded bolt sllaft for clamping together f'irst and second workpieces.
FIG. 8a is a partial sectional view of a lock nut according to the present invention prior to installation.
FIG. 8b is a partial sectional view of tlle lock nut of FIG. 8a after installation.
FIG. 9 is a c omparative graphical i]lustratic)n of the torque performance of a lock nut according to the present invention and a prior art lock nut.
John P. PAl~ERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-3 illustrate various views of a lock nut 10 according to a first exemplary embodiment of the invention comprising generally a body member 20 having a threaded bore 22 along a bore axis for receiving a threaded shaft, a top end 24, a bottom end 26, and a circumferential side portion 28. The side portion 28 of the body member 20 typically has a hexagonal surface or other partially closed surface configuration to facilitate e ngagement thereabout with a torque applying or wrenching tool, as is known generally. The lock nut is preferably fonned uniiarily of a ductile and resilient metal material, like low carbon steel or stainless steel, and may be plated and or heat treated.
FIGS. 1-3 il.lustrate at least one deformable slot 30 disposed on the side portion 28 of the body member 20 and extending into the tllreaded bore 22, and in other embodiments the slot 30 extends only partially through the body member toward the threaded bore 22. In the exemplary embodiment, two deformable slots 30 are disposed on opposing side portions of the body member 20 thereby defining posts 32 and 34 at corner sections of the hexagonal wrenching surfaces interconnecting a lower portion 25 and an upper poltion 27 of the body nlember 20, wherein each deformable slot 30 is disposed substantially transversely relalive to tlle bore axis.
More generally, the body member 20 may include a plurality of deformable slots 30 extending toward or into the bore axis, thereby forming a corresponding plurality ol' posts. Disposing the slots substantially transversely to the bore axis and substantially symmetrically thereabout provides balanced retention of the lock nut 10 about the shafL In the exemplaly embodiment, tlle plurality of deformable slots 30 are disposed along a common plane d;sposed substantially transversely relative to the bore axis, and in other alternative embodimellts one or more of the plurality of deformable slots 30 may be offset frolll each otller along the bore axis, as shown by tlle phantom line slot 31 in FIG. 1.
FIGS. 1-3, and particularly FIG. 3, illustrate the nut deforming members John P. PAl~ERSONt Jr. et al. Atty. Docket No. 8147 "Undeforrned Lock Nut With Slot"
40 protruding from the bottom end 26 of the body member 20, wherein the nut deforming members 40 are each aligned axially with a corresponding deformable slot 30. In the preferred of embodiment of FIGS 1-3, t]le nut deforming members 40 have sections extending radially outwardly from the slots 30 also. According to this aspect of the invention, the nut deforming members 40 are depressible axially toward the corresponding deformable slot 30 to deform the body 3nernber 20 by deformably urging portions of the loweI portion 25 thereof into the deformable slots 30 upon installation of the lock nut as discussed further below.
In FIGS 1-3, the nut deforming 3members 40 are formed by an ann lar portion 42 disposed peripherally about the bottom end 26 of the body member 20, wherein the annular portio~~ 42 and the bottom end 26 form a recess or depression 44 on the bottom end 26 of l:he lock nut. Portions of tlle annular portion 42 aligned substantially axially with corresponding slots 30 defolm the body mernber 20 upon installation of the lock nut as discussed further below. Notably, t}le lock nut and more particularly the tllreaded bore 22 is undeformed prior to installation, which reduces manufacturing costs and greatly reduces the first installation torque, thereby providing remarkably more consisteIltly low start torques.
Referring to FIG. 3, the nut deforming mernbers 40 of this invention rnay be described more generally as radial outer portions 19 extending axially beyond tlle radial innermost portions 21 of the boffom end 26 of tlle body member 20 adjacent the threaded bore 22. This permits the radial outer portions 19 of the lower portion 25 of the body melllber 20 to be forced upwardly relative to the radial innermost portions 21. Additionally, tlle nut deforming merllbers 40 are not necessarily arlnular as shown in FIGS. 1-~. In other embodiments, the nut deforming members 40 are, for example, partially annular as shown in FIGS. 4 and 5 and discussed further below.
The nut deforming member 40, however, may more generally be any member protruding fiom the bottom end 26 of the body men~ber 20 useable in combination with a corresponding slot 30 for deforming tlle threaded bore 22 as discussed below.
FIGS. 1-3 also illustrate tlle lowel portion 25 of tlle body member 20 John P. PAl~ERSOl~l, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock ~ut With Slot"
having a skirt 46 extending substantially radially olltwardly beyond the side portion 28 thereof. The skirt 46 includes a lower surface 47 extending slopingly away from the bottom end 26 of the body member 30 at an angle ~ relative thereto, wherein the annular portion 42 is formed peripherally on a terminating bottom end of the skirt 46.
The skirt 46 and the bottoDl end 26 thus form the depression 44 having a substantially concaved surface, but which may alternatively have an arcuate shape, or frusto-conical shape, or a combination of arcuate and frusto-conical shapes.
Table I below provides approximate exemplary dimensional ranges for several parameters of the lock nut disclosed in FIGS. 1-3, wherein S is the height of the slot 30 along the bore axis, P is the width of the posts 32 and 34 transverse to the bore axis, D is the height of the body member 20 along the bore axis, F is the height of the lower portion 25 of the body member 20 along the bore axis, and H is the overall height of the lock nut along the bore axis. The angle ~ for these exemplary dimensions is betweel~ approximately 10 degrees and approximately 20 degrees.
TABLE I
(~1ETRlCDim~nsionsinMill~eters) Size S P ]~Ml~ ~ H
M12(6H Thread) 0.070/().060 0.265/.~5 1).4~ 0.2~/0.215 0.670/0.660 FIGS. 4 and 5 illustrate various views of a lock nut 11 according to a second exemplary embodiment of the invention also comprising generally a body mernber 20 llaving a threaded bore 22 along a bore axis for receiving a thleaded shaft, a top end 24, a bottom end 26, and a circumfelential side portion 28 configured to facilitate engagen1ent thereabout with a torque applying or wrenclling tool, as discussed above. Tlle lock nut 1] of FIGS. 4 and 5 is also preferal~ly formed unitarily asdiscussed above with reference to the embodiments of l~I(JS 1-3.
FIGS. 4 and 5 illustrate two derormable slots 30 disposed on side John P. PA~ERSOI~, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut W:ith Slot"
portions of the body rnember 20 and extending into, or at least partially toward, the threaded bore 22. The deformable slots 30, which may be ot~fset axially, are disposed on substantially opposing side portions of the body rnember 20 thereby defining posts 32 and 34 at corner sections of the hexagonal wrenching surfaces interconnecting a lower portion 25 and an upper portion 27 of the body member 20, wherein each deformable slot 30 is disposed substantially transversely to the bore axis. The deformable slots 30 in the second embodiment of FIGS. 4 and 5 may be configured alternatively as discussed above.
FIGS. 4 and 5 also illustrate nut deforming members 40 protruding from the bottom end 26 of the body member 20, whe]ein each nut defonning member 40 is aligned substantially axially with a corresponding deformable slot 30. The nut deforming members 40 are depressible axially toward the corresponding deforrnable slot 30 to deform tlle bocly member 20 by deformably urging portions of the lower portion 25 thereof into the deformable slots 30 upon installation of the lock nut as discussed further below.
In ~IGS. 4 and 5, the nut deforming u~embers 40 are partially annular portions 43 disposed peripherally on the bottom end 26 of the body mernber 20, wherein the partially anmllar portions 43 and tlle bottom end 26 also form a recess or depression 44 on the bottom end 26 of the lock nut. The partially annular portions 2a 43 are aligned substantially axially with a corresponding slot 30, for subsequently deforming the body men1ber 20. Notably, the body member 20 and more particularlytlle threaded bore 22 is umdeformed prior to installation, wllich reduces manufacturing costs and greatly reduces the first installation ~orque, tllereby providing remarkably more consistently low start torques.
FIGS. 6a and 6b illustrate various views of a lock nut 12 according to a tllird exemplaly embodiment of tlle invelltion comprising generally a body member 20 with slots 30 and corresponding substantially axially aligned nut defonning members 40 formed as cams 45 llaving a curved lower surface, wlScll may be conSgured as linear nlelllbers or as partially annular meml~ers 43 similar to the second exenlplary John P. PATI ERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
embodiment of FIGS. 4 and 5. FIG. 6b also illustrates the nut deforming members 40 as radial outer portions 19 extending axially beyond the radial innermost portions 21 of the bottom end 26 of the body member 20 adjacent the threaded bore 22, as discussed above. Notably the body member 20 and more particularly the threaded bore 22 thereof is undeforrned prior to installation, which reduces manufacturing costs and greatly reduces the i'i]-st installation torque, thereby providing remarkably more consistently low start torques.
FIG. 6a also illustrates a washer 60 rotatably coupled to the lower portion 25 of the body member 20 in manner typical of such nut and washer assemblies. The washer 60 of FIG. 6a is a substantially conical spring washer having an upper surface 66, which slopes away from the bottom end 26 of the body member20 and accommodates the one or more nut deforming members 40 protruding from the bottom end 26 thereof prior to installation of the lock nut 10. The spring washer 60 also includes a ternlinating end with an annu]ar portion 68 disposed peripherally thereon, and a substantially conically sloping lower surface 67, wl~ich forms a substantially concaved lower surface 69 with the lower portion 25 of the body member.
FIG. 7 illustrates a previously undeformed lock nut of the present invention generally tllreadably disposed about a threaded s]laft S extending through two adjacently positioned workpieces W, and W2 wherein the lower portion 25, andmore particularly the nut deforming member or members 40, are facing toward and engageable with tl~e workpiece W2to deform the lock nut upon installation thereof.
The threaded sllaft S may be part of a bolt B disposed through botll workpieces Wl and W2, or the threaded s]laft S may alternatively be a thleaded stud member formed integrally with the workpiece Wl and extending tllrougll tl1e second workpiece W2, wllerein the shaft S and lock nut retain or fasten the workpieces Wl and W2 together.
FIG. 8a illustrates that tlle lock nllts of this invention and especia]ly tlle tllreaded bore 22 thereof is undeformed prior to complete installation, and moreparticularly prior to e ngagelnent of the nut defolmillg melllber or meml)ers 40 with t]le workpiece. According to t]lis aspect of tlle invention, tlle installation torque is John P. PAl~ERSONl Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
minim~l until the nut deforrning member or members 40 engage, directly or indirectly, the workpiece and begin to urge or deflect the lower portion 25 of the body member 20 upwardly toward the upper portion 27 thereof to deformably close the slots 30. The novel lock nuts of the present invention thus have a greatly reduced initial installation torque in comparison to lock nuts of the prior art.
In FIG. 7, the lock nut is installed fully, wherein the nut deformirg members 40 have been urged upwardly toward the upper portion 27 of the body member 20, and more particularly into a corresponding deformable slot 30, which is at least partially closed by a deformed portion 23 of the body member 20. Although the particular lock nut embodiment of FIG. 7 may be more representative of the lock nut in the exemplary embodiment of FIGS. 4 and 5 in combination with a washer mernber or the lock nut in lhe exemplary embodiment of FIG. 6, the at least partially closed deformable slot 30 and the deformed portion 23 of the body member 20 are representative generally of the va]ious exemplary embodin1ents disclosed herein after 1~ installation.
In operation, generally, an initially ulldeformed lock nut of this invention is advanced along the ~hreaded shaft S toward and into contact with the workpiece W2 by application of a torque either directly to the wrenching surface of the lock nut or to a llead portion of the bolt B, until the one Ol more nut deforming members 40protruding from the bottonl end 26 of the body member 20 engage the workpiece W2, either directly or indirectly depending on the particular configuration thereof.Generally, the one or more slots 30 are deformably closed, at least partially, thereby deforming the cross-section of the threaded bore 2~ from a substantia]ly constant pitch and circular shape to a deforrned out of ph~se pit(h with an elliptical shape. FIG. 8b illllstrates the deforn ation of the body member and more particularly the lowerportion 25 thereof resulting in a compressive force directecl generally radially inwardly toward the threaded shaft S. FIG. 8b illustrates ~urtl~er that the upwardly deflected lower portion 25 of the body member 20 also deforms tl~e he]ical uniformity along at least an a~ial portion of tlhe threaded bore 22 of the body member 20, particularly John P. PAl rERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed L~ck Nut With Slot"
toward the lower portion 25 thereof, which results from increased spacing between some threads and decreased spacing between others.
In the exemplary embodiment of ~IGS. 1-3, the skirt 46 and more particularly portions of the annular portion 42 thereof protruding from the lower portion 26 of the body member are deflected upwardly toward the upper portion 27thereof and into the corresponding deforrnable slots 30 upon engagement of the skirt 46 with the workpiece W2, thereby deforming the body member 20 generally, especially the lower portion 25 thereof as discussed above. More particularly, FIG. 8b illustrates a portion of the upwardly deflected annular portion 42 applying compressive forces directed radially inwardly toward the threaded shaft S defonning the helical uniforrnity and cross-sectional shape of the threaded bore 22 thereby generally increasing the prevailing torque on the lock nut, which retains the lock nut about the threaded shaft.
Other peripheral portions of the skirt 46 are deflected upwardly about the side portion 28 of the body rnember 20, since the posts 32 and 34 are relatively unyielding to axially cornpressive forces, thereby also contributing generally to deformation of the body member 20 and thus to retention of the lock nut about the threaded shaft S.
In the exemplary embodiments of FIGS. 4 and 5, the partially annular portions 43 protruding fronl the lower portion 25 of the body member 20 are deflected upwardly toward the upper portion 27 thereof and into corresponding deformable slots 30 upon engagement of tlle partially annular portions 43 with the workpiece W2, thereby deforming the body member 20 generally, especially the lower portion 25 thereof as discussed above. More particularly, FIG. 8b ilhlstrates, iIl phantom, one of the upwardly denected partially annular portions 43 applying compressive forces directed radially inwardly toward the threaded shait S defomling the helical uniforn1ity and cross-sectional sl]ape of the threaded bore 22 thereby generally increasing the prevailing torque on the lock nut, which retains the lock nut about the threaded shaft.
In the exelnplary embodilnellts of FIGS. 6a and 6b, tlle nut deforming members 40 protruding from the lower portion 25 of the body member 20 are deflected upwardly toward the upper portion 27 of the body member 20 and into the John P. PAl~ERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
deformable slots 30 upon clamping engagement of the spring washer 60 between thenut deforming members 40 and the workpiece W2, thereby deforrning the body member 20 generally, especially the lower portion 25 thereof as discussed above.More particularly, FIG. 7 illustrates that as the clamped spring washer 60 begins to flatten, the downwardly sloping upper surface 66 thereof is deflected upwardly toward the lower portion 25 of the body member 20, wherein one or more portions of the upper surface 66 thereof engage corresponding canns 45 disposed protrudingly from the bottom end 26 of the body member 20 thereby deforrnably closing, at least partially, corresp~,nding deformable sl~ts 30. The upwardly deflected cams 45 apply compressive forces directed radially in~vardly toward the threaded shaft S deforming the helical uniformity and cross-sectional shape of the threaded bore 22 thereby generally increasing the prevailing torque on the lock nut, which retains the lock nut about the threaded shaft, similar to lhe nut deforming members illustrated in FIG. 8b.
The lock nuts shown in the exemplary embodiments of FIGS. 1-8 have remarkably improved torque performance in comparison to prior art lock nuts. FIG.
9 illustrates, more particlllarly, that the lock nuts of the present invention have generally a substantially recluced instal]ation, or first on torque, in comparison to prior art lock nuts, which resulls in part from the fact that the lock nuts of the present invention are not deformed until they are fi] st installed, which is true of allembodiments disclosed herein. Thus a significant installation torque is not required, at least initially, to overcome frictional forces resulting from lock nut deformation, as in the prior art, since the lock nuts of the present invention are not deformed until after engagement with the workpiece. FIG. 9 also illustrates that the novel lock nuts of the present invention hclve a relatively consistent torque performance over several installation and removal cycles, in con1parison to prior art lock nuts, which is another remarkable characteristic of the present invention. Tlle lock nuts of the present invention are thus more li:kely to exceed industly perfonnallce specifications.
Tlle torque performance of the nov( l lock nuts of the present invention also have a relatively reduced statistical spread over several installation and removal John P. PAl~ERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
cycles, which is yet another remarkable characteristic of the present invention.Reduced statistical spread of torque performance is a very important manufacturing and applications consideration, since it results in the rejection of fewer parts for failure to comply with industry performance specifications for a particular application, and decreases the probability that a lock nut not in compliance with a required specification will be used in a particular application.
While the foregoing written description of the invention enables one of ordinary skill in the art to make and use what is at present considered to be the best mode of the invention, it will be appreciated and understood by those of ordinary skill the existence of variations, combinations, modifications and equivalents within the spirit and scope of the specific exemplary embodiments disclosed herein. The present invention therefore is to be limited not by the specific exemplary embodiments disclosed herein but by all embodiments within the scope of the appended claims.
BACKGROUND OF THE INVENTION
The invention re]ates generally to lock nuts t]~readably engageable and lockingly retainable about a threaded s]laft, and more particularly to lock nuts which are undeformed prior to installation, and lock nuts l~aving improved torque performance, while provil:~ing extremely lo~ "filst on" torques, including relatively consistent torque per~ormance with reduced statistical spread over several installation and removal cycles.
Lock nuts have many configurations and are used widely in industry.
U.S. Patent No. 2,142,~19 entitled "Self Gripping Device" issued on 3 January 1939 to Olson and coumlonly assigned herewith, for exalnple, discloses a loc~ing nut having diametrically opposed slots disposed transversely therein to form yieldable sections, which are deflected axially to distort a portion of the tllreaded bore by helical disalignrnent thereof along the yieldable sections, prior to installation thereof, thereby providing a balanced frictional grip on a threaded sllaft subsequently disposed througl the threaded bore of the lock nut.
U.S. Paeent No. 3,659,491 entitled "Rotatable Nut ~nd Washer Assembly"
issued on 2 May 1972 to Duffy et al discloses a lock nut forll1ed of a threaded inner barrel coupled by a web to a hexagonally shaped o-lter barrel having a radially extending peripheral skirt, which is formed as a llnitaly nut melllber. Tlle nut of U.S.
John P. PATIERSO~I, Jr. et al. Atty. Docket No. 8147 "Undeforrned Lock Nut With Slot"
Patent No. 3,659,491 is rotatably coupled to a frusto-conical spring washer, which forms an assembly, wherein the spring washer is flattenable betveen the nut and a workpiece, to provide a reverse axial tension on the nut and a radially inwardlydirected compressive force on the inner barrel, which locks the nut about a threaded S shaft. l~he spring washer in U.S. Patent No. 3,659,491 becomes rotationally fixed relative to the workpiece, thereby reducing the torque required to install the lock nut about the shaft and thereby also reducing damage to the surface of the workpiece, which otherwise occurs when the washer is rotationally fixed relative to the rlut. The lock nut of U.S. ~atent No. 3,659,491 however is relatively expensive to manufacture, particularly the unitaly nut portion, which is fabricated from sheet metal.
Generally, prior art lock nut retention performance is diminished substantially upon removal of the nut from the threaded shaft. In lock nuts of the type disclosed in U.S. Patent No. 2,142,819 discussed above, the diminished retentionperforrnance results from a tendency of the s]ots to widen after the lock nut isdisposed about the shaft during tlle first installation and subsequent first removal tllerefrom. This adverse effect on prior art lock nut retention performance is particularly significant after the first installation and removal cycle, and continues to worsen as the lock nut is subject to repeated cycles of installation and removal, which commonly occurs in applications where the nut lnust be removed and reinstalled for ~0 service and maintenance.
FIG. 9 of tlle present patent application illustrates graphically the torque performance of prior loclc nuts over several installation and removal cycles generally, and more particularly illustrates tlle relatively large torque required for the first installation, or first on, in comparison to the substantially reduced torque required for the first removal, or first off, whereill the torque performance continues to diminish, tho-lgh at a lesser rate, with increasing numbers of on and off cycles. FIG. 9 also illustrates the relatively incollsistent torque perforlllance of prior art lock nuts, particularly over tlle interval between tlle "1 0~" througll tlle "3 OFF" wllereafter tlle torque performance is more consistent over tlle intelval bet~veen the "3 Ol:~F" and the John P. PATI ERSON~ Jr. et al Atty. Docket No. 8147 "Undeforrned Lock Nut Wilh Slot"
"S OF~". FIG. 9 i]lustrates further the tendency of prior art lock nut torque per~ormance not to comphJ with an industry established torque specification as it decreases below the SPEC curve somewhere between the "2 OFF" and "3 OF~", which often results from the relatively large statisiical spread associated with the torque performance of prior art lock nuts.
The copending U.S. Application No. 08l628,923 entitled "Prevailing Torque Nut" discloses a novel lock nut configuration having relatively consistent torque performance and reduced statistical spread over several repeated cycles of nut installation and nut removzl about a threaded shaftl which is a remarkable improvement over prior art lock nuts. The copending U.S. Application No. 08/628,982 entitled "Method for Sizing a Lock Nut" discloses a method of manufacturing a lock nut that includes a step of threading an enlarged sizing tool through a deformedportion of a lock nut threaded bore during the manufacture thereof and prior to actual use of the lock nut, which further improves the torque periormance thereof. Moreparticularly, the sized lock nut of IJ.S. Application No. 08l628,923 has among other advantages a relatively more consistent torque performarlce over several installation and removal cycles, including a reduced first on torque and reduced statistical spread.
The tllreaded bore portions of these lock nuts however are deformed prior to installation.
T}le present invention is drawn to improved lock n-lts tllat overcome problerns in the prior art, and rnore pa1ticularly to lock nuts having further improvements in torque performance, including greater consistency of torque performance, substantially reduced first on torque, and reduced statistical spread.
It is a more particular object of the present invention to provide a novel lock nut threadably engageable and lockingly retainable about a tllreaded shaft extending through a workpiece, the lock nut having at least one deforrnable slotdisposed on a side portion tllereof and disposed transversely relative to the lock nut bore axis, the lock nut also llaving a nut deforming member protruding from a bottom end tllereof, whereirl at least a portion of the nut deforming member is in sul~stantial John P. PAl~ERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
axial alignment with the deformable slot. Notably, the lock nut is undeformed prior to installation thereof about the threaded shaft. The nut deforming member is howeYer engageable with the workpiece to deform the lock nut upon threadably installing the lock nut about the threaded shaft, thereby retaining the lock nutthereabout, whereby the lock nut has a relatively consistent torque performance with reduced statistical spread over several installation and removal cycles of the nut about the threaded shaft.
It is also an object of the invention to provide a novel lock nut of the more particular configuration described a~ove, wherein the lower portion of the lock nut includes a skirt extending outwardly beyond the side portion thereof, and wherein the mlt deforming member is an annular portion of the skirt disposed peripherally on the lower end thereof, wherein a bottom portiorl of the lock nut has a substantially concaved or countersunk surface.
It is another object of the invention to provide a novel lock nut of the more particular configurations described above, wherein the lock nut includes a plurality of at least two deformable slots disposed on side portions thereof and a corresponding plurality of nut deforming members disposed on the bottom end of the body member in substantial axial alignment with the corresponding deformable slot.
In one embodiment, the deformable slots are disposed substantially transversely to the bore axis and substantially symmetrically thereabout, and in anotller embodiment one or more of the plurality of deformable slots is offset axially along the bore axis relative to the other deformable slots.
It is a furthl r object of the invention to provide a novel lock nut of the more particular configurations described above, wllerein the lock nut includes asubstantially conical spring washer rotatably coul)led to the lower portion of the body member. A sloping upper sllrface of the spring wasller slopes away from the bottom end of the body member and accommodates t]le one or more nut deforming members therebetween, wllereby the nut deforming members are engageable with the upper surface of tlle spring wasller to deform the body nlelllber upon clamping and flattening John P. PAl rERSON, Jr. et al. Atty. Docket No. 8147 "Undeforrned Lock Nut With Slot"
the spring washer between the bottom end of the body member and a workpiece.
These and other objects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the I~vention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps arereferenced by corresponding numerals and indicators.
BRIEF DESCRIPTION OF TIIE I~ AWINGS
FIG. 1 is a side elevational view of a lock nut according to a first exemplary embodiment of the invention.
FIG. 2 is a lop plan view of the lock nut of FIG. 1.
FIG. 3 is a sectional view along lines a - a of FIG. 2.
FIG. 4 is a side elevational view of a lock nut according to a second exemplary embodiment oi the invention.
FIG. 5 is a lop plan view of the lock nut of FIG. 4.
FIG. 6a is a ~partial sectional side elevational view of a lock nut according to a third exemplary embodin1ent of the invention.
FIG. 6b is a partial sectional view along lines b-b of FIG. 6a.
FIG. 7 is a side elevational view of a lock nut according to the present invention disposed al~out a tllreaded bolt sllaft for clamping together f'irst and second workpieces.
FIG. 8a is a partial sectional view of a lock nut according to the present invention prior to installation.
FIG. 8b is a partial sectional view of tlle lock nut of FIG. 8a after installation.
FIG. 9 is a c omparative graphical i]lustratic)n of the torque performance of a lock nut according to the present invention and a prior art lock nut.
John P. PAl~ERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-3 illustrate various views of a lock nut 10 according to a first exemplary embodiment of the invention comprising generally a body member 20 having a threaded bore 22 along a bore axis for receiving a threaded shaft, a top end 24, a bottom end 26, and a circumferential side portion 28. The side portion 28 of the body member 20 typically has a hexagonal surface or other partially closed surface configuration to facilitate e ngagement thereabout with a torque applying or wrenching tool, as is known generally. The lock nut is preferably fonned uniiarily of a ductile and resilient metal material, like low carbon steel or stainless steel, and may be plated and or heat treated.
FIGS. 1-3 il.lustrate at least one deformable slot 30 disposed on the side portion 28 of the body member 20 and extending into the tllreaded bore 22, and in other embodiments the slot 30 extends only partially through the body member toward the threaded bore 22. In the exemplary embodiment, two deformable slots 30 are disposed on opposing side portions of the body member 20 thereby defining posts 32 and 34 at corner sections of the hexagonal wrenching surfaces interconnecting a lower portion 25 and an upper poltion 27 of the body nlember 20, wherein each deformable slot 30 is disposed substantially transversely relalive to tlle bore axis.
More generally, the body member 20 may include a plurality of deformable slots 30 extending toward or into the bore axis, thereby forming a corresponding plurality ol' posts. Disposing the slots substantially transversely to the bore axis and substantially symmetrically thereabout provides balanced retention of the lock nut 10 about the shafL In the exemplaly embodiment, tlle plurality of deformable slots 30 are disposed along a common plane d;sposed substantially transversely relative to the bore axis, and in other alternative embodimellts one or more of the plurality of deformable slots 30 may be offset frolll each otller along the bore axis, as shown by tlle phantom line slot 31 in FIG. 1.
FIGS. 1-3, and particularly FIG. 3, illustrate the nut deforming members John P. PAl~ERSONt Jr. et al. Atty. Docket No. 8147 "Undeforrned Lock Nut With Slot"
40 protruding from the bottom end 26 of the body member 20, wherein the nut deforming members 40 are each aligned axially with a corresponding deformable slot 30. In the preferred of embodiment of FIGS 1-3, t]le nut deforming members 40 have sections extending radially outwardly from the slots 30 also. According to this aspect of the invention, the nut deforming members 40 are depressible axially toward the corresponding deformable slot 30 to deform the body 3nernber 20 by deformably urging portions of the loweI portion 25 thereof into the deformable slots 30 upon installation of the lock nut as discussed further below.
In FIGS 1-3, the nut deforming 3members 40 are formed by an ann lar portion 42 disposed peripherally about the bottom end 26 of the body member 20, wherein the annular portio~~ 42 and the bottom end 26 form a recess or depression 44 on the bottom end 26 of l:he lock nut. Portions of tlle annular portion 42 aligned substantially axially with corresponding slots 30 defolm the body mernber 20 upon installation of the lock nut as discussed further below. Notably, t}le lock nut and more particularly the tllreaded bore 22 is undeformed prior to installation, which reduces manufacturing costs and greatly reduces the first installation torque, thereby providing remarkably more consisteIltly low start torques.
Referring to FIG. 3, the nut deforming mernbers 40 of this invention rnay be described more generally as radial outer portions 19 extending axially beyond tlle radial innermost portions 21 of the boffom end 26 of tlle body member 20 adjacent the threaded bore 22. This permits the radial outer portions 19 of the lower portion 25 of the body melllber 20 to be forced upwardly relative to the radial innermost portions 21. Additionally, tlle nut deforming merllbers 40 are not necessarily arlnular as shown in FIGS. 1-~. In other embodiments, the nut deforming members 40 are, for example, partially annular as shown in FIGS. 4 and 5 and discussed further below.
The nut deforming member 40, however, may more generally be any member protruding fiom the bottom end 26 of the body men~ber 20 useable in combination with a corresponding slot 30 for deforming tlle threaded bore 22 as discussed below.
FIGS. 1-3 also illustrate tlle lowel portion 25 of tlle body member 20 John P. PAl~ERSOl~l, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock ~ut With Slot"
having a skirt 46 extending substantially radially olltwardly beyond the side portion 28 thereof. The skirt 46 includes a lower surface 47 extending slopingly away from the bottom end 26 of the body member 30 at an angle ~ relative thereto, wherein the annular portion 42 is formed peripherally on a terminating bottom end of the skirt 46.
The skirt 46 and the bottoDl end 26 thus form the depression 44 having a substantially concaved surface, but which may alternatively have an arcuate shape, or frusto-conical shape, or a combination of arcuate and frusto-conical shapes.
Table I below provides approximate exemplary dimensional ranges for several parameters of the lock nut disclosed in FIGS. 1-3, wherein S is the height of the slot 30 along the bore axis, P is the width of the posts 32 and 34 transverse to the bore axis, D is the height of the body member 20 along the bore axis, F is the height of the lower portion 25 of the body member 20 along the bore axis, and H is the overall height of the lock nut along the bore axis. The angle ~ for these exemplary dimensions is betweel~ approximately 10 degrees and approximately 20 degrees.
TABLE I
(~1ETRlCDim~nsionsinMill~eters) Size S P ]~Ml~ ~ H
M12(6H Thread) 0.070/().060 0.265/.~5 1).4~ 0.2~/0.215 0.670/0.660 FIGS. 4 and 5 illustrate various views of a lock nut 11 according to a second exemplary embodiment of the invention also comprising generally a body mernber 20 llaving a threaded bore 22 along a bore axis for receiving a thleaded shaft, a top end 24, a bottom end 26, and a circumfelential side portion 28 configured to facilitate engagen1ent thereabout with a torque applying or wrenclling tool, as discussed above. Tlle lock nut 1] of FIGS. 4 and 5 is also preferal~ly formed unitarily asdiscussed above with reference to the embodiments of l~I(JS 1-3.
FIGS. 4 and 5 illustrate two derormable slots 30 disposed on side John P. PA~ERSOI~, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut W:ith Slot"
portions of the body rnember 20 and extending into, or at least partially toward, the threaded bore 22. The deformable slots 30, which may be ot~fset axially, are disposed on substantially opposing side portions of the body rnember 20 thereby defining posts 32 and 34 at corner sections of the hexagonal wrenching surfaces interconnecting a lower portion 25 and an upper portion 27 of the body member 20, wherein each deformable slot 30 is disposed substantially transversely to the bore axis. The deformable slots 30 in the second embodiment of FIGS. 4 and 5 may be configured alternatively as discussed above.
FIGS. 4 and 5 also illustrate nut deforming members 40 protruding from the bottom end 26 of the body member 20, whe]ein each nut defonning member 40 is aligned substantially axially with a corresponding deformable slot 30. The nut deforming members 40 are depressible axially toward the corresponding deforrnable slot 30 to deform tlle bocly member 20 by deformably urging portions of the lower portion 25 thereof into the deformable slots 30 upon installation of the lock nut as discussed further below.
In ~IGS. 4 and 5, the nut deforming u~embers 40 are partially annular portions 43 disposed peripherally on the bottom end 26 of the body mernber 20, wherein the partially anmllar portions 43 and tlle bottom end 26 also form a recess or depression 44 on the bottom end 26 of the lock nut. The partially annular portions 2a 43 are aligned substantially axially with a corresponding slot 30, for subsequently deforming the body men1ber 20. Notably, the body member 20 and more particularlytlle threaded bore 22 is umdeformed prior to installation, wllich reduces manufacturing costs and greatly reduces the first installation ~orque, tllereby providing remarkably more consistently low start torques.
FIGS. 6a and 6b illustrate various views of a lock nut 12 according to a tllird exemplaly embodiment of tlle invelltion comprising generally a body member 20 with slots 30 and corresponding substantially axially aligned nut defonning members 40 formed as cams 45 llaving a curved lower surface, wlScll may be conSgured as linear nlelllbers or as partially annular meml~ers 43 similar to the second exenlplary John P. PATI ERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
embodiment of FIGS. 4 and 5. FIG. 6b also illustrates the nut deforming members 40 as radial outer portions 19 extending axially beyond the radial innermost portions 21 of the bottom end 26 of the body member 20 adjacent the threaded bore 22, as discussed above. Notably the body member 20 and more particularly the threaded bore 22 thereof is undeforrned prior to installation, which reduces manufacturing costs and greatly reduces the i'i]-st installation torque, thereby providing remarkably more consistently low start torques.
FIG. 6a also illustrates a washer 60 rotatably coupled to the lower portion 25 of the body member 20 in manner typical of such nut and washer assemblies. The washer 60 of FIG. 6a is a substantially conical spring washer having an upper surface 66, which slopes away from the bottom end 26 of the body member20 and accommodates the one or more nut deforming members 40 protruding from the bottom end 26 thereof prior to installation of the lock nut 10. The spring washer 60 also includes a ternlinating end with an annu]ar portion 68 disposed peripherally thereon, and a substantially conically sloping lower surface 67, wl~ich forms a substantially concaved lower surface 69 with the lower portion 25 of the body member.
FIG. 7 illustrates a previously undeformed lock nut of the present invention generally tllreadably disposed about a threaded s]laft S extending through two adjacently positioned workpieces W, and W2 wherein the lower portion 25, andmore particularly the nut deforming member or members 40, are facing toward and engageable with tl~e workpiece W2to deform the lock nut upon installation thereof.
The threaded sllaft S may be part of a bolt B disposed through botll workpieces Wl and W2, or the threaded s]laft S may alternatively be a thleaded stud member formed integrally with the workpiece Wl and extending tllrougll tl1e second workpiece W2, wllerein the shaft S and lock nut retain or fasten the workpieces Wl and W2 together.
FIG. 8a illustrates that tlle lock nllts of this invention and especia]ly tlle tllreaded bore 22 thereof is undeformed prior to complete installation, and moreparticularly prior to e ngagelnent of the nut defolmillg melllber or meml)ers 40 with t]le workpiece. According to t]lis aspect of tlle invention, tlle installation torque is John P. PAl~ERSONl Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
minim~l until the nut deforrning member or members 40 engage, directly or indirectly, the workpiece and begin to urge or deflect the lower portion 25 of the body member 20 upwardly toward the upper portion 27 thereof to deformably close the slots 30. The novel lock nuts of the present invention thus have a greatly reduced initial installation torque in comparison to lock nuts of the prior art.
In FIG. 7, the lock nut is installed fully, wherein the nut deformirg members 40 have been urged upwardly toward the upper portion 27 of the body member 20, and more particularly into a corresponding deformable slot 30, which is at least partially closed by a deformed portion 23 of the body member 20. Although the particular lock nut embodiment of FIG. 7 may be more representative of the lock nut in the exemplary embodiment of FIGS. 4 and 5 in combination with a washer mernber or the lock nut in lhe exemplary embodiment of FIG. 6, the at least partially closed deformable slot 30 and the deformed portion 23 of the body member 20 are representative generally of the va]ious exemplary embodin1ents disclosed herein after 1~ installation.
In operation, generally, an initially ulldeformed lock nut of this invention is advanced along the ~hreaded shaft S toward and into contact with the workpiece W2 by application of a torque either directly to the wrenching surface of the lock nut or to a llead portion of the bolt B, until the one Ol more nut deforming members 40protruding from the bottonl end 26 of the body member 20 engage the workpiece W2, either directly or indirectly depending on the particular configuration thereof.Generally, the one or more slots 30 are deformably closed, at least partially, thereby deforming the cross-section of the threaded bore 2~ from a substantia]ly constant pitch and circular shape to a deforrned out of ph~se pit(h with an elliptical shape. FIG. 8b illllstrates the deforn ation of the body member and more particularly the lowerportion 25 thereof resulting in a compressive force directecl generally radially inwardly toward the threaded shaft S. FIG. 8b illustrates ~urtl~er that the upwardly deflected lower portion 25 of the body member 20 also deforms tl~e he]ical uniformity along at least an a~ial portion of tlhe threaded bore 22 of the body member 20, particularly John P. PAl rERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed L~ck Nut With Slot"
toward the lower portion 25 thereof, which results from increased spacing between some threads and decreased spacing between others.
In the exemplary embodiment of ~IGS. 1-3, the skirt 46 and more particularly portions of the annular portion 42 thereof protruding from the lower portion 26 of the body member are deflected upwardly toward the upper portion 27thereof and into the corresponding deforrnable slots 30 upon engagement of the skirt 46 with the workpiece W2, thereby deforming the body member 20 generally, especially the lower portion 25 thereof as discussed above. More particularly, FIG. 8b illustrates a portion of the upwardly deflected annular portion 42 applying compressive forces directed radially inwardly toward the threaded shaft S defonning the helical uniforrnity and cross-sectional shape of the threaded bore 22 thereby generally increasing the prevailing torque on the lock nut, which retains the lock nut about the threaded shaft.
Other peripheral portions of the skirt 46 are deflected upwardly about the side portion 28 of the body rnember 20, since the posts 32 and 34 are relatively unyielding to axially cornpressive forces, thereby also contributing generally to deformation of the body member 20 and thus to retention of the lock nut about the threaded shaft S.
In the exemplary embodiments of FIGS. 4 and 5, the partially annular portions 43 protruding fronl the lower portion 25 of the body member 20 are deflected upwardly toward the upper portion 27 thereof and into corresponding deformable slots 30 upon engagement of tlle partially annular portions 43 with the workpiece W2, thereby deforming the body member 20 generally, especially the lower portion 25 thereof as discussed above. More particularly, FIG. 8b ilhlstrates, iIl phantom, one of the upwardly denected partially annular portions 43 applying compressive forces directed radially inwardly toward the threaded shait S defomling the helical uniforn1ity and cross-sectional sl]ape of the threaded bore 22 thereby generally increasing the prevailing torque on the lock nut, which retains the lock nut about the threaded shaft.
In the exelnplary embodilnellts of FIGS. 6a and 6b, tlle nut deforming members 40 protruding from the lower portion 25 of the body member 20 are deflected upwardly toward the upper portion 27 of the body member 20 and into the John P. PAl~ERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
deformable slots 30 upon clamping engagement of the spring washer 60 between thenut deforming members 40 and the workpiece W2, thereby deforrning the body member 20 generally, especially the lower portion 25 thereof as discussed above.More particularly, FIG. 7 illustrates that as the clamped spring washer 60 begins to flatten, the downwardly sloping upper surface 66 thereof is deflected upwardly toward the lower portion 25 of the body member 20, wherein one or more portions of the upper surface 66 thereof engage corresponding canns 45 disposed protrudingly from the bottom end 26 of the body member 20 thereby deforrnably closing, at least partially, corresp~,nding deformable sl~ts 30. The upwardly deflected cams 45 apply compressive forces directed radially in~vardly toward the threaded shaft S deforming the helical uniformity and cross-sectional shape of the threaded bore 22 thereby generally increasing the prevailing torque on the lock nut, which retains the lock nut about the threaded shaft, similar to lhe nut deforming members illustrated in FIG. 8b.
The lock nuts shown in the exemplary embodiments of FIGS. 1-8 have remarkably improved torque performance in comparison to prior art lock nuts. FIG.
9 illustrates, more particlllarly, that the lock nuts of the present invention have generally a substantially recluced instal]ation, or first on torque, in comparison to prior art lock nuts, which resulls in part from the fact that the lock nuts of the present invention are not deformed until they are fi] st installed, which is true of allembodiments disclosed herein. Thus a significant installation torque is not required, at least initially, to overcome frictional forces resulting from lock nut deformation, as in the prior art, since the lock nuts of the present invention are not deformed until after engagement with the workpiece. FIG. 9 also illustrates that the novel lock nuts of the present invention hclve a relatively consistent torque performance over several installation and removal cycles, in con1parison to prior art lock nuts, which is another remarkable characteristic of the present invention. Tlle lock nuts of the present invention are thus more li:kely to exceed industly perfonnallce specifications.
Tlle torque performance of the nov( l lock nuts of the present invention also have a relatively reduced statistical spread over several installation and removal John P. PAl~ERSON, Jr. et al. Atty. Docket No. 8147 "Undeformed Lock Nut With Slot"
cycles, which is yet another remarkable characteristic of the present invention.Reduced statistical spread of torque performance is a very important manufacturing and applications consideration, since it results in the rejection of fewer parts for failure to comply with industry performance specifications for a particular application, and decreases the probability that a lock nut not in compliance with a required specification will be used in a particular application.
While the foregoing written description of the invention enables one of ordinary skill in the art to make and use what is at present considered to be the best mode of the invention, it will be appreciated and understood by those of ordinary skill the existence of variations, combinations, modifications and equivalents within the spirit and scope of the specific exemplary embodiments disclosed herein. The present invention therefore is to be limited not by the specific exemplary embodiments disclosed herein but by all embodiments within the scope of the appended claims.
Claims (10)
1. A lock nut threadably engageable and retainable about a threaded shaft extending through a workpiece, the lock nut comprising:
a body member having a threaded bore along a bore axis for receiving the threaded shaft, the body member having a top end, a bottom end, and a side portion;
a deformable slot disposed on the side portion of the body member and extending into the body member toward the threaded bore;
a nut deforming member protruding from the bottom end of the body member, at least a portion of the nut deforming member aligned axially with the deformable slot, the threaded bore undeformed prior to installation of the lock nut about the threaded shaft, the nut deforming member protruding from the bottom end of the body member engageable with the workpiece to deform a lower portion of the body member and a lower portion of the threaded bore upon threadably installing the lock nut about the threaded shaft, thereby retaining the lock nut about the threaded shaft, whereby the lock nut has a low first on torque and relatively consistent torque performance with reduced statistical spread over several installation andremoval cycles of the nut about the threaded shaft.
a body member having a threaded bore along a bore axis for receiving the threaded shaft, the body member having a top end, a bottom end, and a side portion;
a deformable slot disposed on the side portion of the body member and extending into the body member toward the threaded bore;
a nut deforming member protruding from the bottom end of the body member, at least a portion of the nut deforming member aligned axially with the deformable slot, the threaded bore undeformed prior to installation of the lock nut about the threaded shaft, the nut deforming member protruding from the bottom end of the body member engageable with the workpiece to deform a lower portion of the body member and a lower portion of the threaded bore upon threadably installing the lock nut about the threaded shaft, thereby retaining the lock nut about the threaded shaft, whereby the lock nut has a low first on torque and relatively consistent torque performance with reduced statistical spread over several installation andremoval cycles of the nut about the threaded shaft.
2. The lock nut of Claim 1, the nut deforming member is an at least partially annular portion disposed peripherally on the bottom end of the body member.
3. The lock nut of Claim 1, a lower portion of the body member having a skirt extending outwardly beyond the side portion of the body member, the skirt having a sloping lower surface extending from the bottom end of the body member,the nut deforming member is an annular portion disposed peripherally on a terminating end of the skirt, wherein the skirt and the bottom end form a depression on the lower portion of the body member.
4. The lock nut of Claim 1, the body member having a plurality of at least two deformable slots disposed on the side portion of the body member, eachdeformable slot disposed substantially transversely to the bore axis, the plurality of deformable slots disposed substantially symmetrically about the bore axis.
5. The lock nut of Claim 4, at least one of the plurality of deformable slots is offset axially along the bore axis relative to the other deformable slots.
6. The lock nut of claim 1, the nut deforming member is a cam protruding from the bottom end of the nut.
7. The lock nut of Claim 6, the body member having a plurality of at least two deformable slots disposed on the side portion of the body member, eachdeformable slot disposed substantially transversely to the bore axis, the body member having a plurality of cams corresponding to the plurality of deformable slots, each cam protruding from the bottom end of the body member aligned substantially axially with the corresponding deformable slot, and each cam engageable with the workpiece todeform the lower portion of the body member and the lower portion of the threaded bore upon threadably installing the lock nut about the threaded shaft, thereby retaining the body member about the threaded shaft.
8. The lock nut of Claim 7, the plurality of deformable slots disposed substantially symmetrically about the bore axis.
9. The lock nut of Claim 6 further comprising a washer rotatably coupled to the lower portion of the body member
10. The lock nut of Claim 1, the deformable slot extending through the side portion of the body member and into the threaded bore.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/934,380 US5915902A (en) | 1997-09-19 | 1997-09-19 | Undeformed lock nut with slot |
| US08/934,380 | 1997-09-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2246070A1 true CA2246070A1 (en) | 1999-03-19 |
Family
ID=25465471
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002246070A Abandoned CA2246070A1 (en) | 1997-09-19 | 1998-08-28 | Undeformed lock nut with slot |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US5915902A (en) |
| EP (1) | EP0903508A1 (en) |
| JP (1) | JPH11148509A (en) |
| AU (1) | AU708510B2 (en) |
| BR (1) | BR9803460A (en) |
| CA (1) | CA2246070A1 (en) |
| TW (1) | TW374104B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107701551A (en) * | 2017-09-20 | 2018-02-16 | 重庆佳岳机械制造有限公司 | A kind of fixing device for installing for Motor vehicle for carrying passengers licence plate |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6095733A (en) * | 1998-06-29 | 2000-08-01 | Huck International, Inc. | Threaded fastener with determinable clamp load |
| JP3772265B2 (en) * | 2000-05-17 | 2006-05-10 | 株式会社シマノ | Painted parts for fishing |
| US6520464B1 (en) | 2000-06-12 | 2003-02-18 | Rockwell Automation Technologies, Inc. | Assembly for facilitating mounting and removal of an article |
| SE516862C2 (en) * | 2000-07-14 | 2002-03-12 | Allgon Ab | Reconciliation screw device and method and resonator |
| DE10161026A1 (en) * | 2001-12-12 | 2003-06-26 | Hilti Ag | Self-locking screw element |
| US7094238B2 (en) * | 2002-11-22 | 2006-08-22 | Sdgi Holdings, Inc. | Variable angle adaptive plate |
| US7857566B2 (en) | 2005-07-14 | 2010-12-28 | Reactive Spring Fasteners, Llc | Reactive fasteners |
| US7462007B2 (en) * | 2004-07-14 | 2008-12-09 | Paul Sullivan | Reactive biasing fasteners |
| US7727239B2 (en) * | 2005-06-10 | 2010-06-01 | Zimmer Technology, Inc. | Milling system with guide paths and related methods for resecting a joint articulation surface |
| US7437976B1 (en) | 2006-09-05 | 2008-10-21 | Harold Goldbaum | Positive auto-blocking nut ensemble and torqueing tool |
| US20090064480A1 (en) * | 2007-09-11 | 2009-03-12 | Hiroaki Migita | Method of a fastening a bolt and a nut and their fastening structure |
| US8100617B2 (en) * | 2008-01-22 | 2012-01-24 | Nexteer (Beijing) Technology Co., Ltd. | Fastener system with frangible member |
| US8541916B2 (en) * | 2009-12-17 | 2013-09-24 | Siemens Energy, Inc. | Nut securing arrangement for electrical generator |
| JP2014224594A (en) * | 2013-05-17 | 2014-12-04 | 嘉彦 芋田 | Locking nut |
| DE102014002192A1 (en) * | 2014-02-11 | 2015-08-13 | Spieth-Maschinenelemente Gmbh & Co. Kg | machine element |
| CN104019110A (en) * | 2014-06-12 | 2014-09-03 | 费小芳 | Nut |
| CN104019111A (en) * | 2014-06-12 | 2014-09-03 | 航天精工股份有限公司 | Locknut set and using method thereof |
| JP6542567B2 (en) * | 2015-04-09 | 2019-07-10 | シマノコンポネンツ マレーシア エスディーエヌ．ビーエッチディー． | Fishing reel washer |
| DE102015117784A1 (en) * | 2015-10-19 | 2017-04-20 | Kathrein-Werke Kg | Expanded rivet connection and method for mounting the same |
| CN108626221B (en) * | 2017-03-21 | 2022-03-04 | 中兴通讯股份有限公司 | Radio frequency module and shell structure and screw thread self-locking structure thereof |
| TWM582084U (en) * | 2019-03-15 | 2019-08-11 | 王鼎瑞 | Anti-loose structure for fastener |
Family Cites Families (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US613777A (en) * | 1898-11-08 | Nut-lock | ||
| GB190307767A (en) * | 1903-04-03 | 1903-12-17 | Steel Nut And Joseph Hampton L | New or Improved Lock-nuts for Screw Bolts, and Screwed Rods and Tubes and others Screws. |
| US1351676A (en) * | 1919-04-26 | 1920-08-31 | Walter S Myers | Nut-lock |
| US1449683A (en) * | 1921-08-06 | 1923-03-27 | William E Lippold | Nut lock |
| GB188267A (en) * | 1922-02-01 | 1922-11-09 | Harry Gardner Norwood | Improvements in nut locks |
| US2142819A (en) * | 1936-03-23 | 1939-01-03 | Illinois Tool Works | Self-gripping device |
| US2243515A (en) * | 1941-01-16 | 1941-05-27 | Multigrip Safety Nut Inc | Bolt and nut lock |
| GB551534A (en) * | 1941-08-29 | 1943-02-26 | R K Dundas Ltd | Improvements in or relating to lock nuts |
| BE460443A (en) * | 1945-06-13 | |||
| US2570863A (en) * | 1945-10-12 | 1951-10-09 | Mac Lean Fogg Lock Nut Co | Lock nut |
| DE1400205A1 (en) * | 1961-05-26 | 1969-02-27 | Hanfland Curt H | Lock nut |
| US3659491A (en) * | 1971-03-08 | 1972-05-02 | Trw Inc | Rotatable nut and washer assembly |
| US4043369A (en) * | 1976-03-11 | 1977-08-23 | Abernethy Robert R | Edge deformable lock nut |
| FR2357771A1 (en) * | 1976-07-09 | 1978-02-03 | Thiant Boulonnerie | Safety threaded nut with flanged base - is designed to be deformed on tightening using conical section giving positive locking |
| GB2119886B (en) * | 1982-05-05 | 1986-01-15 | Alan Elgar Herbert Ellis | Self locking nuts |
| DE3319244A1 (en) * | 1983-05-27 | 1984-11-29 | Lauer, Christine, 8770 Lohr | Self-locking nut, screw or threaded pin |
| FR2597386B1 (en) * | 1986-04-17 | 1989-10-13 | Framatome Sa | GRIPPING DEVICE FOR TENSIONING TIGHTENING ELEMENTS. |
| US4986712A (en) * | 1989-12-18 | 1991-01-22 | Emhart Industries, Inc. | Fastener assembly |
| US5662443A (en) * | 1996-04-08 | 1997-09-02 | Illinois Tool Works Inc. | Prevailing torque nut |
-
1997
- 1997-09-19 US US08/934,380 patent/US5915902A/en not_active Expired - Fee Related
-
1998
- 1998-08-28 CA CA002246070A patent/CA2246070A1/en not_active Abandoned
- 1998-09-09 EP EP98307288A patent/EP0903508A1/en not_active Ceased
- 1998-09-15 BR BR9803460-0A patent/BR9803460A/en not_active Application Discontinuation
- 1998-09-16 TW TW087115471A patent/TW374104B/en active
- 1998-09-17 AU AU85215/98A patent/AU708510B2/en not_active Ceased
- 1998-09-21 JP JP10266766A patent/JPH11148509A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107701551A (en) * | 2017-09-20 | 2018-02-16 | 重庆佳岳机械制造有限公司 | A kind of fixing device for installing for Motor vehicle for carrying passengers licence plate |
Also Published As
| Publication number | Publication date |
|---|---|
| BR9803460A (en) | 1999-10-26 |
| EP0903508A1 (en) | 1999-03-24 |
| TW374104B (en) | 1999-11-11 |
| AU8521598A (en) | 1999-04-01 |
| AU708510B2 (en) | 1999-08-05 |
| JPH11148509A (en) | 1999-06-02 |
| US5915902A (en) | 1999-06-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |