US2166299A - Rotary adjustable-tension jar mechanism - Google Patents

Description

y 9 S. J. KENNEDY ET AL 2, 5, 99

ROTARY ADJUSTABLE-TENSION JAR MECHANISM Filed Sept. 20, 1938 5 Sheets-Sheet 2 I [III/III, 25

July 18, 1939. '5. J. KENNEDY ET Al. ROTARY ADJUSTABLE-TENSION JAR MECHANISM Patented July 18, 1939 UNITE STATES ATENT OFFIE ROTARY ADJ USTABLE-TEN SION JAR ME CHAN ISM Application September 20, 1938, Serial No. 230,810

20 Claims.

This invention is a mechanism for the highly effective delivery of an upward jar or shock as is sometimes very desirable in the operation of various kinds of tools and tool strings in the oil-well industry; though it is to be understood that the present invention may be utilized in combination with several other fields of utility, the mechanism being in the nature of a mechanical movement in its broadest aspect.

In divers operations in connection with earth wells, deep or otherwise, it very frequently occurs that tools or other apparatus so tightly freeze in a well that very considerable shock impulses must be imposed to sumciently free the stuck part so that it may be pulled from the hole, or side tracked or driven down.

A number of jarring contrivances have been devised and promoted on the market with the purported function of imparting a sudden jar to a stuck part in a Well. A very material objection to several types of such contrivances is that they work on such a principle of action that no reliance can be placed on the actual degree of tension, in a tool string, at which the device will antoinatically release and effect the jar impulse. The present invention aims particularly at the elimination of this very uncertainty.

Further, a purpose of the invention is to provide a jar mechanism of extreme simplicity, of high reliability, of comparatively few and very rugged parts, and especially free from intricate processes of operation so that the average mechanic may readily make replacements in shop or field, when needed, and may quickly assemble the elements and assemblies of the mechanism and easily install the device in a string of parts, such as including a fishing tool of any of the well known varieties.

Noticeably, a purpose of the invention is to provide a jar device incorporating a master resistor Whose re-action factor may easily be increased or decreased by manually controlled means at the head of a well in which the jar device may be in place at any depth, and this by the mere rotation of an upper assembly of the device as to a connected lower assembly, to which, for instance a fishing tool may be attached.

Divers forms of well tool jars heretofore proposed have relatively operative parts designed for the express function of setting up a mutual sliding engagement one on the other and thus involving surface friction as the factor controlling the desired tripping of the jar hammer, and some of the tools have the idea of adjusting the degree of friction. It is a distinctive purpose and feature of the instant invention to provide a heavy duty jar mechanism wholly eliminating frictional resistance as the factor controlling the trip of the jar hammer locking means. In this aspect, an object of the invention to provide a jar mechanism incorporating a jar hammer and an anvil to be struck thereby, with means to relea'sably interlock them in open relation for strike, in combination with a tensioning element or barrel slid-- able on the hammer without functional resistance and provided with means pressing the barrel to a fixed seat on the hammer with an adjustable degree of resilient reaction to be overcome before the barrel moves from its hammer seat in clear distinction to any form of jar tool wherein this movement entails great frictional resistance on two or more riding surfaces; the overcoming of the stated resilient reaction above alluded to resulting, in this invention, in the positive unlocking of the hammer for strike.

Another objective of this invention is to provide for the change of resilient reaction at any position of the mechanism as when in a well hole, by rotation of the tool string inthe usual direction of rotation of the string and for the reduction of the reaction by reverse rotation of the string without liability of breaking (that is unscrewing) of any string joints.

The invention consists of certain advancements in this art as set forth in the ensuing disclosure and having, with the above, additional objects and advantages as hereinafter developed, and whose constructions, combinations and details of means will be made manifest in the description of the herewith illustrative embodiments; it being understood that modifications, variations and adaptations may be resorted to within the scope, principle and spirit of the invention as it is more directly claimed hereinbelow.

Figure 1 is an axial section of the jar mechanism connective in a drill, or other apparatus, string.

Figure 2 is an elevation of the unlocking element of the tool.

Figure 3 is an elevation of cooperative barrel and sleeve parts of the tool in closed relation for co-rotation.

Figure 4 is a sectional detail of a form of reactor device including a stack of steel spring washers.

Figure 5 is a sectional detail of a form of jacketed, compressible rubber rings for re-actor function.

Figure 6 is a cross-section of the sleeve showing the releasing pawls or dogs in plan, and.

Figure 7 is a sectional detail of the pawl device.

Figure 8 is an axial section showing a multiplespring hook-up.

Figure 9 is a sectional detail illustrating the incorporation of a hydraulic cushion for the reactor.

Figure 10 is an elevational section of a variant form.

In its preferred form the mechanism includes an upper sub or joint part 2 connective to the contiguous end of a tool string (not shown) forming a part of apparatus for use in well hole operations, the jar mechanism including, also, a lower or bottom sub 3 for attachment of the desired implement to be lowered and operated in the hole.

Removably attached to the sub 2 is the upper end of a casing part or barrel 4 in which there is a concentric, slidable stem or mandrel having screwed or otherwise attached removably, to its opposite or lower end, an enlarged or hammer portion 5. The barrel 4 and the shank or mandrel 5 of the hammer are provided with mutually engaging seat shoulders 4a and 5a to limit sliding telescopic action relatively; that is, in the present case, so that the barrel and the hammer mandrel can move only so far in one direction as to one another but providing sliding capacity upwardly of the barrel, as here shown, as when tension is applied to the top sub 2.

It is desirable to set up a definite, but readily variable resistance to such movement of the barrel from its seat on shoulder 5a of the hammer mandrel and to set up such reaction without contacting surfaces which slide relatively and take therreaction force; in otherwords, to eliminate the use of surfaces sliding under great frictional load. There is therefore provided a cushion or resilient device so interposed between the barrel and the mandrel that it exerts pressure on the barrel tending to constantly force the shoulder 4a of the barrel 4 to or toward the mandrel shoulder or seat 5a. In Fig. 1, the reaction device includes a compressive spring I telescoped in the barrel 4 about the mandrel 5; the barrel here being shown having an inner cup or hub 8 surrounded by the spring 'I and forming a suitable bearing for the adjacent portion of the mandrel. The upper end of the spring 1 bears on an antifriction support 9 which is engaged on top by an elongate nut I0 suitably threaded at H on the upper end of the hammer mandrel 5, whose top is provided with a crown ring |2 normally pressed by the reaction device I, to the near face of the sub 2.

The nut II is suitably keyed or splined at |3 to the bore wall of the barrel 4 and it will be seen that if the mandrel 5 is held against rotation, by suitable means, the nut II will move down in the barrel if this is, for instance turned right-hand (looking down, Fig. 1) and if the rotation is reversed the nut will move up in the barrel. If, therefore, the spring 1 of desired strength and resistance set is installed in the socket in the barrel 4 this can be shifted upwardly on the mandrel 5 only when the set or resistance of the spring I is overcome. The degree of resilience or reaction of the control spring I can be changed at will by rotation of the tool sub 2 as just above described, if the mandrel is held against rotation.

Screwed at I5 onto the lower sub 3 is the lower end of a suitable casing part or sleeve l6 which is slidably fitted on the hammer 6 and is splined at I! thereto so that the hammer will be held against rotation if the sub 3 and subjacently attached tool parts are held against rotation, as when a fishing tool may have engaged a fish or be otherwise caught in a well hole.

The hammer 6 is shown in Fig. 1 as in open or spaced relation in the sleeve l6 as to an anvil forming shoulder I8 of the sleeve bore and when the hammer 6 is moved suddenly up and strikes said shoulder a desired upward jar or shock is given the string casing sleeve 5 and the tool therebelow attached.

A feature of this invention resides in the provision of a suitable, substantial, reliable and substantially friction-free means to releasably lock the mandrel hammer 6 in its open position, Fig. 1, and which means is controlled by the sliding action of the upper casing barrel 4. In the present case the sleeve bore is annularly grooved to present a sharply inturned facet l9 and a downwardly converged face 2|! of a form to more or less fit the outer faces of a plurality of pawls or dogs 2| whose inner and lower or converged ends have hooks 22 interlocking removably in respective pockets 23 provided therefor in the adjacent portion of the mandrel 5. The several pawls 2| are arranged in spaced relation in a circle about the mandrel and will move outward on their lower end pivots 22 at any angular relation of the groove facet IS with which the upper ends of the pawls 2| are designed to automatically interlock so as to prevent undesired upward movement of the mandrel 5 in the anvil sleeve I6; the pawls taking a diverging position from their pivots 22 in the mandrel and thiswise forming compression bars in event of tension on the mandrel as to the subjoined tool parts-when locked by the pawls.

The pawls 2| are each provided with springs 25 seated in the mandrel 5 whereby to automatically thrust the pawls outwardly into interlock with the hammer sleeve when the mandrel 5 is moved into the sleeve IE to bring the pawls into register with the locking groove faces |92|l. The compression-taking pawls 2| will withstand a tremendous load, as by tension of the mandrel, without releasing the latter from the anvil sleeve. At the same time this form of locking means sets up no more resistance in unlocking effort than is required to move the pawls 2| inward against their springs 25 and the resultant of force present on the inwardly and upwardly pitched facets H! of the locking groove.

Means are provided to effect the automatic release of the locking pawls 2| from the anvil sleeve l6 when desired and under control of the tension barrel 4 and its re-actor device I. As here shown the release means includes a collar 26 turnably swivelled by a screw coupling or ferrule 21 to the lower end of the barrel 4 and being slidably mounted on the mandrel 5 so that as the barrel may be moved upwardly, on the mandrel, when overcoming the re-actor I, the releasing collar 26 will function to pull the pawls 2| inwardly to fully release the hammer mandrel from the anvil sleeve and thereby allow the hammer 6 to strike the anvil l8. The releasing collar 26 has a series of lateral, through holes 28 in which the pawls 2| may swing in or out on their pivots 22 and the lower ends of these holes are formed with upwardly diverging sills 29 complementary to the outer faces of the pawls. In the locking position of the pawls the sills lie close up under the pawls and it therefore requires but a small amount of upward sliding movement of the tension barrel 4 on the mandrel 5 and but .s'light repression of the resilient re-actor, such as spring 1, or other suitable means, in order that the set of locking. pawls 2|. may be contracted to fully release the hammer means so that it will be pulled upwardly by the tension applying .barrel 4 acting through the re-=actor device 7 after the original .or arbitrarily adjusted resistance thereof has been overcome. It willbe understood that when this mechanism is combined in a well-tool stringthis string is placed under tension,-aiter the fishing tool has been engaged, say,.on a fish in a hole, and the known elasticity of the drill or tool string is the tensioning force applied on the pulling barrel 4 .to trip the locking pawlsZl from the anvil device 6. This string tension causes the hammer to strike the anvil.

Should the first .shock or shocks fail to loosen "the fish in the hole the driller in charge may easily increase the compression of the re-actor means 1 .by rotating the upper string assembly (above the mandrel) to run the nutor adjuster Ill down more on the spring 1 thereby increasing its resistance to upward movement of the barrel 4 from its seat 50. on the locked mandrel 5. A reverse rotation of the upper string assembly will decrease the resistance of the reactor.

. Itis desirable that provision be made-against so far compressing the spring 1 that the pawls could not be released, that is-against jamming the shoulder 4a to seat 5a so tightly that the barrel could not move up. A safety nut 3| is placed on threads ll of the mandrel 5 to stop down-screwing of the control nut it.

.It will be observed that the two casing sections, barrel 4 and anvil sleeve I6, are relatively axially shiftable and that they are relatively rotatable to .provide for the turning of the nut Ill on the mandrel. 5 while this is keyed to the sleeve (at ll) but provision is made for the co-rotation .of thelcasing sections' l and 16 as is frequently neededin well, hole jobs.

Such coaction,'rotatively, isaccomplished by the device of complementary meeting jaws 4?) on the bottom end edge of the barrel 4 and jaws liibon the opposite endof the anvil sleeve l6; these'opposite jaws beingadapted to..automatically engage as the hammer 6 is shifted to full open position from the anvil l8, Figs. 1 and 3. Since there may be an undeterminable rotation of the barrel 4 after the jar blow has been struck, following unlocking function of the trip means IS, the tips of the jaws 4b-I6b are preferably sharpenedas seen in Fig. 3 to insure the effective register of the jaws in closed position when the hammer Bis reset to open or ready position for jar stroke.

The operation is as follows: assuming that the main or re-actor spring I has been compressed by nut 10, before or-after insertion of the tool in a hole, it functions to hold the shoulder 4a-of the tensionable barrel 4 down on the shoulder 5d of the shank 5 of the hammer head 6 with a constant-reaction on the shank nut It! to pull the hammer shank (or mandrel) 5 upward in the barrel 4. At this time the light springs 25 are tipping the latches 2| outward under the shoulders I9 to serve to keep sleeve part It merely suspended in open positionon the mandrel. The latches do not lock the barrel to the mandrel or shank 5.

The spring I is thus a cushion member between the nut Ill and the barrel 4. When a blow is tobe struck by head 6 on anvil l8 enough tension. is. placed on barrel 4 to measurably compress the spring 1 and move shoulder4 up from shoulder 5 to. aLdegree necessary to bring the tripshoulders "29.,of releasing collar 26 up to latches 2l-uand;the.barrel 4 must move upward stillmore on shank 5,-againstthe cushion spring I, until the collar can move the latches inward from the shoulders l9. As soonzas the latches are released from shoulders IS the compressed spring 1, its barrel 4 and the hammer (head 6 shank 5) fly upward as a. unitdue to the tension onthe barrel string, and the head 6 impacts theanchored (fish held) anvil l8.of sleeve 16. Itswill be seen that the barrel 4.pulls up on cushion spring I and this pulls up on nut ill, and this pulls up on the hammer shank or mandrel 5. It is the string tension that strikes the head 6 on to anvil I8, because the crown ring l2 sets against the-joint 2. .In this device the spring 1 sets up no reaction on the latches 2| but only between the shoulders 4a- -5a and the latches are under. release effort only when main spring has been compressed enough to move the collar 26 upward on the standing shank 5 of the hammer. In other words, the latches are merely loaded by the weight of the sleeve l6 and-subjoined parts.

It is to benoticed that resistance variation of the re-actor l and ,co-rotational inter-lock of the jaws 4b and lBb is readily obtained while the tool bottom implements are down in a well hole.

A modified form of re-actor device is shown in Fig. 4 as including a stack of spring steel rings la which each have axially off-set portions lb forming compressible humps of hugh resiliency. Another form of re-actor is shown in Fig. 5 wherein a rubber cushion device is involved. This device employs a stack of stiff rubber rings To each of which is nested in a complementary pair of housing rings 1d between which the embedded rubber ring is extrusive inwardly and outwardly under pressure.

A modification of the re-actor is shown in Fig. 8 as including a multiplicity of the coil. springs l spaced along the mandrel and each having a nut Illa splined at !3a in a respective section 4b or of the barrel (4); these springs I are concurrently compressed or relieved by rotation of the barrel, while the mandrel is non-rotative.

For the purpose of protecting the parts of the jar against undesired strain, after the unlock of the hammer, the spring chamber in the barrel, as for spring 1, Fig. 9, may be charged with a suitable quantity of liquid L which will re-act to check the stroke of the barrel subsequent to the hammer release.

The mandrel crown I2 is provided with a suitable packing lZa to keep the barrel free from liquid; the lower end of the barrel having a packing I211. The upper end of the sleeve 16 has a packing ring 1611 working on the tripper collar 26, and the hammer 6 has a cup, or fluid pressure-set, packing 6a cooperating with packing 12a to keep the sleeve it free of liquid.

When desired, a means is provided to prevent the pulling strain on the tool or fish from being taken to and by the main spring means I and to prevent secondary shocks thereon after release of the locking pawls 2| from being imposed on thespring means. In Fig. 10 there is shown abarrel section 4 connected to a lower barrel section 4 by means of a joint element 4d to provide access to the bores of these sections'for assembly of insides. The main spring I, in this case, surrounds mandrel 5 which has a seat ring .35, forthe spring, conically fitting and holding a split, top ring or stop 36 set in a groove 31 in the mandrel. The expansion spring 1 bears down on a ball bearing 38 which engages the upper end of a tension-adjusting nut I here threaded in the barrel section 4 and splined to the mandrel 5.

The expanding effort of the spring I pushes the barrel downward until a split, stop shoulder ring 4f thereof engages a mutual shoulder or stop 50 of the mandrel 5 (like 4a,5a above mentioned). When tension is placed on barrel 4-4" if the spring I is overcome then the stop ring M will slide up with the barrel on the mandrel 5 and the locking pawls 2| will be released from the sleeve l6 and the hammer 6 will snap to its anvil.

Following the release of the hammer-mandrel 5-6 the burden of the tension on the sleeve and fish string l63 is, by the device of Fig. 1, transmitted to the spring 1, and further this may be subjected to secondary jars after the pawls 2| are released, from the sleeve. In Fig. 10 the main spring 1 is protected by a load-carrying means on the mandrel engageable with a cooperative element of the barrel device. Thusly, the mandrel 5 has an annular bead 5:1: normally spaced above the near end of the joint element 4d to provide for up-shift of the barrel 44" on and as to the mandrel 5 until the pawls 2! are tripped by the collar 26. After hammer release, the bead 5x will arrest the barrel shift on the mandrel and will be a positive load intercepter and will substitute for the tension regulating spring 1 whose only function will be to provide a yieldable resistor until the pawls are released from the barrel.

What is claimed is:

1. A jar mechanism including a mandrel having a hammer head, a sleeve having an anvil part to be struck by the hammer, latches normally locking the mandrel head and the anvil in spaced relation, a tension device sliding and seating on the mandrel and including a resilient means forcing said device to its mandrel seat, and trip means actuated by the tension device as it is moved from its mandrel seat to trip the locking means and. release the hammer mandrel said trip means including a member fixed to the said device and movable into engagement with the latches to trip them; said device and resilient means and the mandrel moving up as a unit by tension to cause the hammer to strike the anvil.

2. The jar of claim 1; the hammer and the anvil sleeve being splined and the tension device and the mandrel having splined parts, and a swivel connection between the tension device and the hammer mandrel.

3. The jar of claim 1, having a swivel connection between the said resilient means and an adjustable part on the mandrel.

4. A jar mechanism including a sleeve having an intermediate anvil face and a hammer headed mandrel sliding in the sleeve to impact the anvil, a set of pawls for locking the mandrel head in open position from the anvil, a barrel forming a tension device slidable and normally seating on the mandrel, an adjustable re-action spring tending to hold the mandrel to its seat on the barrel, and means including a trip collar fixed on and operative by relative sliding motion of the barrel on the mandrel to engage and automatically release the pawls so that tension effort on the barrel will shift the barrel on the mandrel and compress cushion spring before the pawls are released by the collar.

5. A jar as in claim 4, and means operative by the said device to effect the said re-action adjustment.

6. A jar as in claim 4, and said locking pawls being automatic in locking action independently of the main spring to hold the barrel seated on the mandrel.

7. A jar as in claim 4, said locking pawls carried by one part and interlocking with the other in an angular position about the jar axis independently of the compression of the main spring.

8. The jar of claim 4, and a safety stop for the adjustment of the re-action spring.

9. A jar mechanism including a rotary barrel for attachment in a tension applying apparatus, a hammer having a shank or mandrel sliding and normally seated on a shoulder of the barrel, a re-action spring yieldably thrusting the mandrel to its seat on the shoulder, means operative by the barrel to vary the effort of the spring, an anvil sleeve slidable on the hammer, and means acting automatically independently of the spring to connect the sleeve and the mandrel in hammer open position and being operative by relative motion of a part of the barrel on the mandrel, when the barrel moves from the mandrel shoulder, to release the hammer mandrel from the sleeve for jar stroke.

10. A jar mechanism including an anvil part and a relatively slidable hammer part splined thereto for impacting the anvil, self-setting means carried by one of said parts to automatically lock the hammer in open position, and a tension device including a barrel slidably related to the hammer and normally yieldably seated in a determined position by engagement with a shoulder thereon and. a main spring interposed between the barrel and a part of the mandrel and forcing the barrel to said shoulder and including an instrument for tripping said locking means when a definite tension causes said device to shift sufficiently from its seat on the hammer mandrel.

11. A jar as in claim 10, and means operative by motion of said tension barrel, while the anvil part is held, to vary the yielding resistance of the device against movement from its seat.

12. A jar as in claim 10, and means for corotatively connecting said device and the anvil part.

13. A jar mechanism including an anvil sleeve part and a relatively slidable hammer splined thereon for jarring impact thereon, self-setting pawls carried by one of said parts to automatically lock the hammer in open position, a barrel slidably mounted on the hammer part and means acting to yieldably press the hammer to a predetermined stop position as to the barrel, and said barrel having means to effect release of the locking pawls when the barrel is shifted on the hammer by tension.

14. A jar as in claim 13, and means mounted on the hammer and operative by rotation of the barrel to regulate the re-action of said yieldable means.

15. A jar mechanism including a barrel part and an anvil part having co-operative means for co-rotation of the parts, a hammer splined in the anvil part and having a mandrel slidable in the barrel part and the hammer impactive on the anvil, mutual stop means on the hammer and the barrel parts, means yieldably pressing the barrel to normal rest on its cooperative stop on the hammer with the hammer open from the anvil, means for locking the hammer in such open position, and means operative by the tensioned barrel to actuate the locking means to release the hammer.

16. A jar as in claim 15, and means connecting the hammer and the barrel and operative by relative rotation thereof to vary the re-action of the yieldable means.

17. A jar as in claim 15, said locking means including a set of pawls yieldably mounted in the hammer to interlock with the anvil, and the releasing means including a swivelled collar carried by the barrel to engage with and trip the pawls.

18. A jar as in claim 15, the anvil part having an annular groove in its bore face, and said locking means including a plurality of pawls yieldably interlocking in the groove.

19. A jar mechanism as in claim 1, and including a load carrier to intercept the tension and relieve resilient means of jar and load after the locking means has been tripped.

20. A jar mechanism as in claim 1, and means coming into action following'release of the looking means to substitute for said resilient means to take jar and load therefrom.

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