US3224800A

US3224800A - Adjustable supporting leg

Info

Publication number: US3224800A
Application number: US329339A
Authority: US
Inventors: Robert E Fisher
Original assignee: Up Right Inc
Current assignee: Up Right Inc
Priority date: 1963-05-13
Filing date: 1963-11-29
Publication date: 1965-12-21
Anticipated expiration: 1982-12-21
Also published as: DE1429705A1; GB1009155A

Description

Dec. 21, 1965 R. E. FISHER ADJUSTABLE SUPPORTING LEG 4 Sheets-Sheet 1 Filed NOV. 29, 1963 INVENTOR QoE/Qr E 55H5@ Dec. 21, 1965 R. E. FISHER 3,224,800

ADJUSTABLE SUPPORTING LEG Filed Nov. 29, 1963 4 Sheets-Sheet 2 INVENTOR.

ATTORNEY( Dec. 21, 1965 R.- E. FISHER 3,224,800

ADJUSTABLE SUPPORTING LEG Filed Nov. 29, 1963 4 Sheets-Sheet 5 a F/G, 6

INVENTOR Pat-Q7 E. F/.SHE/

BY MM m ATTORNEYS Dec. 2l, 1965 R. E. FISHER 3,224,800

ADJUSTABLE SUPPORTING LEG Filed Nov. 29, 1965 4 Sheets-Sheet 4 F/ a. /2 Ffa /3 INVENTOR. ,P05597- E. 55H5@ #Trae/w96 United States Patent Oce 3,224,800 Patented Dec. 21, 1965 3,224,800 ADJUSTABLE SUPPORTING LEG Robert E. Fisher, Berkeley, Calif., assignor to Up-Right, Inc., Berkeley, Calif., a corporation of California Filed Nov. 29, 1963, Ser. No. 329,339 3 Claims. (Cl. 287-62) The present application is a continuation-in-part of my copending application Serial No. 279,858, filed in the United States Patent Office on May 13, 1963, now abandoned.

This invention relates to a supporting leg construction, and more particularly to an adj-ustable supporting leg adapted to form part of a scaffold, bed, table or other device in which the effective length of one or more supporting legs is to be varied. Even more particularly, this invention is an improvement on the adjustable leg shown in U.S. Patent No. 2,618,496, issued to Wallace J. S. Johnson on November 18, 1952.

An object of this invention is to provide a supporting leg for a device whose effective length can be adjusted to comparatively coarse and fine degrees.

Another object of the invention is to provide an adjustable leg that is comprised of two telescoping members and in which one member is threaded throughout its length and in which the other member has a threaded portion that can be releasably connected in threaded engagement with the first member.

A Ifurther object of the invention is to provide an adjustable leg that is comprised of two telescoping members in which one member is threaded throughout its length and in which the other member has resilient fingers having threaded nut portions which can be moved into and out of threaded engagement with the first member, and in which stress is placed only on the nut portions of the resilient fingers when the adjusted leg is placed under compression.

Other objects and advantages will become apparent in the course of the following detailed description.

In the drawings forming a part of this application, and in which like parts are designated by like reference numerals throughout the same,

FIG. 1 is a vertical cross-sectional view of an adjustable leg incorporating the principles of the invention, and showing the leg in locked position;

FIG. 2 is a view partly in elevation and partly in section, showing the leg in unlocked position;

FIG. 3 is an elevational view of the leg in locked position;

FIG. 4 is a sectional view taken on line 4-4 of FIG. 3;

FIG. 5 is a three-quarter view of the split sleeve.

FIG. 6 is a side elevation of a preferred alternative embodiment of the sleeve member of this invention;

FIG. 7 is a top perspective view of a special collar adapted to co-operate with the sleeve of FIG. 6;

FIG. 8 is a partial vertical section along line 8 8 of FIG. 6 showing the co-operation of the preferred sleeve and collar in the locked position;

FIG. 9 is a horizontal section along line 9 9 of FIG. 6;

FIG. 10 is a vertical section along line 10-10 of FIG. 9;

FIG. 11 is a View similar to FIG. 9 but showing the parts in the unlocking process;

FIG. 12 is a fragmentary section along line 12-12 of FIG. 1l; and

FIG. 13 is a view similar to FIG. 12 but showing the parts in their relation when the collar is unlocked.

Referring now to the drawings, the adjustable leg 1t) comprises an outer tubular member 11 and an inner member 12 telescopically inserted into member 11. The outer member 11 is secured to a scaffold or the like to form an integral part thereof, `and the inner member 12 extends downwardly into engagement with the ground. The inner member 12 has an upper bearing portion 13 having an outer diameter substantially equal to the inner diameter of member 11 in order to have a sliding telescopic t therewith. The lower end of inner member 12 may be provided with a caster 14, if desired.

The inner member 12 is threaded, as at 1S, for a substantial portion of its length, but the upper hearing portion 13 is Unthreaded for a purpose to be hereinafter described.

The sleeve member 16 utilized in this invention is formed from a tubular member having a relatively thinwalled upper portion 17 which has an innerl diameter substantially equal to the outer diameter of member 11 to permit the insertion of the member 11 into the upper end of the sleeve. The lower portion of the sleeve 16 is formed with a relatively thick-walled nut 18 which has an upper shoulder 19 to vertically engage the lower end 20 of the tubing member 11. The nut 18 has an interior surface extending downwardly from shoulder 19 which is threaded at 21 complementary to the threads 15 of the inner member 12. The nut 18 is provided with an exterior downwardly and outwardly sloping cam surface 22 and a vertical surface 23 extending downwardly from the cam surface 22.

After the threads 21 in the nut have been cut to receive the inner member 11, the sleeve is vertically slotted, as at 24, to form a plurality of fingers 25, each having a relatively thin and flexible upper portion 17a formed from the thin wall part 17 of the sleeve and a lower, relatively thick-walled nut segment 18a formed from nut 18. The flexible finger portions 17a are bent outwardly to impart an inherent tendency to expand the nut segments 18a away from threaded engagement with the inner member when the sleeve is positioned on the outer member 11 as shown in FIGS. 1 and 2.

A locking collar 27 is disposed about the sleeve for vertical movement thereon. To lock the inner and outer members 11 and 12 together, the collar 25 is moved downwardly so that the lower end 28 thereof engages the cam surfaces 22 of the fingers and forces the nut segments 18a radially inwardly to engage the nut threads 21 with the threads 15 of the inner member 12. With the collar 27 moved all the Way downwardly, the lower inner vertical surface 29 of the collar embraces the outer vertical surface 23 of the nut so that the nut segments are locked into firm threaded engagement with the inner member 12. Downward movement of the collar is limited by the engagement of the collar surface 30 with the cam surface 22. j

The locking collar 27 is held in locked position by a generally bail-shaped locking spring 32. This spring has a central portion 33 extending around more than half of the sleeve and vertically engages the upper surface of collar 27 to prevent accidental upward displacement of the collar from locked position (FIG. 3). In addition, the collar has a cupped upper end 34 in which spring 32 is disposed when locked, which prevents accidental dislodgment of the spring.

The spring 32 has portions 35 extending upwardly from the central portion, which portions are bent radially inwardly at 36 and 37 to fit in the diametrically disposed and registering

holes

38 and 39 in the sleeve and tubular member 11. As will be noted in FIG. 1, this last arrangement prevents vertical separation of, and relative rotation between, the sleeve and tubular member.

When adjustment of the leg 10 is desired, the spring 32 is pried out of the cupped end 34 of the collar 27 and is pivoted to the position shown in FIG. 2. The collar 27 is moved upwardly from engagement with the nut segments 18a, which permits the latter to expand outwardly from threaded engagement with the inner member 12. The inner member may then be moved upwardly or downwardly within the outer member 11 to adjust the effective length of the leg structure. The collar is then moved downwardly to force the nut segments 18a back into threaded engagement with the inner member 12.

The spring 32 is then pivoted downwardly and the central portion 33 thereof is snapped into place in the cupped upper end of collar 27 to lock the collar in place.

By virtue of the telescopic movement of the inner and outer members 11 and 12, a rapid adjustment can be made in the effective length of the leg 10. If a finer adjustment is desired, the threaded nut segments 18a are clamped onto the inner member 12 by collar 27, and the inner member is then rotated in the proper direction, which threads the inner member through the nut and produces a corresponding alteration of the telescopic relation of the inner and outer members, thereby modifying the effective length of the leg to a fine degree, depending upon the lead or pitch of the threads.

The major portion of the inner member 12 is threaded, but its upper end is unthreaded so as to prevent complete unscrewing of the members. It is apparent that the unthreading of the inner member within the threaded fingers eventually engages the lower end of its Unthreaded portion with the threaded nut, which precludes further rotation and unscrewing of the inner member. The Unthreaded upper portion of the inner member has a suflicient length to provide a proper telescopic fit with the outer member 11 and insure appropriate support of the latter by the inner member without lateral deflection.

Modification In a preferred embodiment of the invention, the release of the locking collar is facilitated by using a sleeve-andcollar unit such as that shown in FIGS. 6 through 13. In this case, the locking feature is provided by special locking lingers on the sleeve itself, and a special configuration of the collar facilitates purposeful unlocking of the collar while at the same time preventing any accidental unlocking of the mechanism.

In FIG. 6 the preferred sleeve member is generally shown at 116. The threaded fingers 117a of the sleeve member 116 are similar in construction and function to the threaded fingers 17a of the previously described sleeve member 16. However, in the sleeve member 116, it will be noted that the upper ends of the threaded fingers 117a are tapered inwardly, and that locking fingers 140 are provided in the spaces created thereby. Each locking finger 140 is provided with a stop 142 which may be stamped out of or embossed into the locking fingers 140 in any convenient manner.

For co-operation with the sleeve member 116, the preferred embodiment of this invention provides a collar 127 best shown in FIG. 7. The collar 127 has an inner vertical surface 129 which serves the same purpose as the inner vertical surface 29 of the collar 27, and a limit flange 130 whose function is similar to that of surface 30 of the collar 27. The upper horizontal side of the limit flange 130 forms a locking shoulder 144 extending circumferentially of the collar 127. The locking shoulder 144 is interrupted at intervals around its perimeter by unlocking surfaces 146 extending tangentially to the inner perimeter of the limit flange 130. As will be more clearly seen from FIG. 10, the locking ngers 140 are resiliently bent outwardly and may, if desired, be retained against excessive outward movement by the retaining flange 148 of the collar 127. With the collar 127 in locked position, the collar 127 is prevented from sliding upwardly along the sleeve member 116 by engagement of the lower ends of the locking fingers 140 with either the locking shoulder 144 or the radial shoulder 150 of the unlocking surfaces 146. It will be understood that when the collar 127 is in its lowermost locked position, the lower ends of the locking fingers 140 will be somewhat above the level of the radial shoulders 150 of the unlocking surfaces 146.

When it is desired to unlock the sleeve members 116, it is only necessary, as best shown in FIGS. 11-13, to rotate the collar 127 through an angle b (FIG. 11) While pushing it upwardly. In the course of the rotation, the unlocking surfaces 146 engage the locking fingers 140 and bring them into tangency with the inner surface of the limit ange 130. An upward push at this point (FIG. 12) causes the limit flange 130 to slip over the ends of the locking fingers so as to allow the collar 127 to be raised to its unlocked position shown in FIG. 13. When collar 127 has been fully raised to i-ts unlocked position, the stops 142 engage the

shoulders

144 or 150 to prevent further upward movement of the collar. At the same time, the locking lingers 140, whose ends are now -f-ree of the restraint yof the inner surface of limit flange 130, expand again and assist the cam surface 122 of fingers 117a in preventing the collar 127 from falling back down into the locked position until it is purposely pulled back down.

Inasmuch as the preferred embodiment just described dispenses with the spring members 35, the interlock between the sleeve member 116 and the outer member 11 may be accomplished by means of a screw 152. The screw 152 is threaded into the sleeve member 116 and protrudes into an aperture 154 in outer member 11 sufficiently large to permit the weight of outer member 11 to rest on the shoulder 121i of sleeve member 116 rather than on the screw 152.

The above described invention has many significant advantages over adjustable legs such as shown in the above-referred-to Patent No. 2,618,436. The outer member 11 rests directly on the nut segments 18a, and thus there is no force to buckle the relatively thin upper portions 17a of the resilient fingers when the leg 10 is subjected to compressive loads.

The split finger segments 17a of the sleeve are supported throughout their length by the tubular member 11 and thus there is little likelihood of external damage to these fingers.

Since the fiexible parts of the ngers do not have to support a load, the fingers can be more numeous and more flexible, and it is possible to employ a shorter, more compact sleeve which opens and closes more easily as the locking collar is moved up and down.

The locking spring 32, when pivoted upwardly, permits the locking collar to be moved upwardly to unlock the inner and outer members, but when pivoted downwardly it locks the locking collar securely in two ways. In the first place, the spring grips radially against the sides of the sleeve because it extends more than half-way therearound. Secondly, it rests within the cupped upper end of the collar. Thus, double security is provided against the collar being displaced vertically by accident, which would permit the members 11 and 12 to unlock.

The sleeve 16 is separate from the outer tubular member 11 and ycan be easily replaced if damaged merely by removing the spring ends 36 and 37 or screw from the holes 39 and by sliding the sleeve off from the tubular member 11.

It is to be realized that the form of the invention herein illustrated and described is a preferred embodiment of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the attached claims.

Having thus described my invention, what I claim is:

1. An adjustable leg comprising:

a tubing member;

a sleeve telescoped onto an end of said tubing member and fixed with relation thereto, said sleeve having a plurality of resilient outwardly biased gripping and locking fingers, said gripping fingers extending beyond the ends of said locking fingers;

an inner member extending telescopically into said tubing member, said inner member being externally threaded for at least a portion of the length thereof;

said gripping fingers being provided with nut segments on their ends, said nut segments each having an internal shoulder extending inwardly and adapted to abut about said axis thereby engaging said locking fingers said end of said tubing member, said nut segments and forcing them radially inwardly.

being internally threaded complementarily to said 2. The adjustable leg of claim 1 wherein each of said inner member but being biased therefrom by said embossments includes an unlocking surface extending tangripping fingers, said nut segments having a raised 5 gentially to the inner perimeter of said flange.

portion opposite said threaded portion and joined 3. The adjustable leg of claim 2 and a stop extending to said gripping finger by a cam surface; radially outwardly from said locking fingers, said stop a collar axially movable on said sleeve, said collar being adapted to engage said collar when said collar is having an inner surface adapted to engage said cam out of engagement with said raised portion.

surface to force said nut segments radially inwardly 10 into threaded engagement with said externally References Cited by the Examiner threaded inner member; UNITED STATES PATENTS and means for locking said collar in position, said means including a radially inwardly extending ange on said lremer "Zig-1g? collar having portions of the upper horizontal side 15 248 33 1/ 4 Ones thereof substantially normal to the axis of said tube, 89 1 19 9 Randolph 81-113 at least one cam surface on said horizontal side as 2536376 1/1951 Koonz 279-23 an embossment thereon and at least one additional 2618496 11/1952 Johilsn 24S-188A X embossment on said surface circumferentially spaced 2705'605 4/1955 Krelsslg 287-58 from said one cam surface a distance at least equal 2() 2788980 4/1957 Black 279-7 to the width of said locking finger, said locking finger 2791453 5/1957 Baker et al 287-58 being biased radially outwardly between said emboss- 31129 10 12/1963 Bal 248-191 ments whereby the free ends thereof engage said hor- 3157416 11/1964 Sandbakken 287- 58 izontal surface to lock said collar against retrograde movement from said position and said collar may be 25 CARL W TOMLIN Pnmary Examiner' released from said position by twisting said collar I. B TALTON, C- B- PAGAN, ASSSH Examines-

Claims

1. AN ADJUSTABLE LEG COMPRISING: A TUBING MEMBER; A SLEEVE TELESCOPED ONTO AN END OF SAID TUBING MEMBER AND FIXED WITH RELATION THERETO, SAID SLEEVE HAVING A PLURALITY OF RESILIENT OUTWARDLY BIASED GRIPPING AND LOCKING FINGERS, SAID GRIPING FINGERS EXTENDING BEYOND THE ENDS OF SAID LOCKING FINGERS; AN INNER MEMBER EXTENDING TELESCOPICALLY INTO SAID TUBING MEMBER, SAID INNER MEMBER BEING EXTERNALLY THREADED FOR AT LEAST A PORTION OF THE LENGTH THEREOF; SAID GRIPPING FINGERS BEING PROVIDED WITH NUT SEGMENTS ON THEIR ENDS, SAID NUT SEGMENTS EACH HAVING AN INTERNAL SHOULDER EXTENDING INWARDLY AND ADAPTED TO ABUT SAID END OF SAID TUBING MEMBER, SAID NUT SEGMENTS BEING INTERNALLY THREADED COMPLEMENTARILY TO SAID INNER MEMBER BUT BEING BIASED THEREFROM BY SAID GRIPPING FINGERS, SAID NUT SEGMENTS HAVING A RAISED PORTION OPPOSITE SAID THREADED PORTION AND JOINED TO SAID GRIPPING FINGER BY A CAM SURFACE; A COLLAR AXIALLY MOVABLE ON SAID SLEEVE, SAID COLLAR HAVING AN INNER SURFACE ADAPTED TO ENGAGE SAID CAM SURFACE TO FORCE SAIDNUT SEGMENTS RADIALLY INWARDLY INTO THREADED ENGAGEMENT WITH SAID EXTERNALLY THREADED INNER MEMBER; AND MEAND FOR LOCKING SAID COLLAR IN POSITION, SAID MEANS INCLUDING A RADIALLY INWARDLY EXTENDING FLANGE ON SAID COLLAR HAVING PORTIONS OF THE UPPER HORIZONTAL SIDE THEREOF SUBSTANTIALLY NORMAL TO THE AXIS OF SAID TUBE, AT LEAST ONE CAM SURFACE ON SAID HORIZONTAL SIDE AS AN EMBOSSMENT THEREON AND AT LEAST ONE ADDITIONAL EMBOSSMENT ON SAID SURFACE CIRCUMFERENTIALLY SPACED FROM SAID ONE CAM SURFACE A DISTANCE AT LEAST EQUAL TO THE WIDTH OF SAID LOCKING FINGER, SAID LOCKING FINGER BEING BIASED RADIALLY OUTWARDLY BETWEEN SAID EMBOSSMENTS WHEREBY THE FREE ENDS THEREOF ENGAGE SAID HORIZONTAL SURFACE TO LOCK SAID COLLAR AGAINST RETROGRADE MOVEMENT FROM SAID POSITION AND SAID COLLAR MAY BE RELEASED FROM SAID POSITION BY TWISTING SAID COLLAR ABOUT SAID AXIS THEREBY ENGAGING SAID LOCKING FINGERS AND FORCING THEM RADIALLY INWARDLY.