US2008765A

US2008765A - Jar

Info

Publication number: US2008765A
Application number: US579381A
Authority: US
Inventors: Ira J Mccullough
Original assignee: JAMES A KAMMERDINER
Current assignee: JAMES A KAMMERDINER
Priority date: 1931-12-07
Filing date: 1931-12-07
Publication date: 1935-07-23
Anticipated expiration: 1952-07-23

Description

July 23, 1935'.

15.1. MccULLoucH JARY Y,

original Filed Deo. 7., 1931 2 sheets-sheen 1v 1-1 @way/7 QNX .July 23', 1935.

l. J. MCCULLOUGH JAR Original Filed Deo. '7, 1931 2 Sheets-Shea?. 2

Patented July 23, 1935 UNITED STATES JAR Ira J. McCullough, Huntington Park, Calif., as-

signor to .lames A. Kammerdiner, Los Angeles,

Calif.

Application December 7, 1931, Serial No. 579,381 Renewed August 14, 1933 15 Claims.

This invention relates to a well tool and relates more particularly to a jarring tool for use in fishing operations, etc. A general object of the present invention is to provide a practical, effective, adjustable jarring tool useful in shing operations for imparting a jarring action to the fish or lost part in va Well.

An object of this invention is to provide a jarring tool that is operable to effect avery heavy jarring action.

An important object of the invention isv to provide a jarring tool that is adjustable from the surface vof the ground to provide or impart jarring blows of different intensities. The jar provided by this -invention is adjustable when in the well bore and in connection with the sh by simple manipulation of the operating string carrying the jar.

Another object of the invention is to provide a jarring tool of the character mentioned that is operable by simple reciprocation of the operating string. The tool is tripped or actuated to provide the jarring action by putting it under a tensile strain, and is reset by lowering or settling the operating string.

Another object of Ithe invention is to provide a jarring tool that includes two sections related an improved clutch or latch means for releasL ably holding the sections against relative longitudinal movement.

Another object of the invention is to provide a rotary well jar of the character mentioned in which the latch members release simultaneously and almost instantaneously upon the tool being subjected to a pre-determined strain so that there is very little friction and wear on the latch means.

Another object of the invention is to provide a jarring tool o the character described in which the working parts may be regulated or adjusted to release under various tensile strains through a novel mechanical adjusting means.

Another object of the invention is to provide a jarring tool of the character mentioned that does not interfere with the free circulation of fluid from the operating string.

A further object of the invention is to provide a jarring tool that is positive and dependable in operation and that may be easily and quickly reset for further actuation.

a yielding control member for use in a jar- `ring tool that yields but very slightly when subjected to very heavy compression strains.

for limited relative longitudinal movement and.`

A further object of the invention is to provide (Cl. Z55-27) Other objects and features of the invention, will be best and more fully understood from the following detailed description, during which description reference is had to the accompanying drawings, in which:

Fig. l is a side elevation of the tool provided by this invention showing it in an operating string of drill pipe carrying a fishing tool in engagement with a sh in a well bore. Fig. 2 is an enlarged longitudinal detailed sectional view of the upperr portion of the tool showing the parts in the normal or unactuated position. Fig. 3 is an enlarged longitudinal detailed sectional view of the lower' portion of the tool illustrating the parts in the unactuated positions. Fig. 4 is an enlarged longitudinal detailed sectional view of the central portion of the tool showing the releasable clutch means in the released position. Fig. 5 is an enlarged longitudinal detailed sectional view of the central portion of the tool showing the clutch members about to re-engage the teeth on the stem. Figs. 6, 7, 8, 9 and 10 are transverse detailed sectional views taken as indicated by lines 6 6, 1 1, 8 8, 9 9 and I0 I|l on Fig. 2. Fig. 11 is a transverse detailed sectional View taken as indicated by line Il I I on Fig. 3.

The tool provided by my present invention includes, generally, two body sections A and B connected for limited relative longitudinal movement, a mandrel or stem ID slackly and yieldingly connected with ythe section A, clutch means I I on the section B and the stem I0 f or releasably holding the sections A and B against relative longitudinal movement, and means I2 for regulating or adjusting the means II.

The sections A and B are the main or body parts of the tool and form a slackly linked or connected assembly adapted to be interposed in an operating string of drill pipe S as illustrated in Fig. 1 of the drawings. The sections A and B 4 are connected for limited relative longitudinal movement and are telescoped one into the other. In the particular form of the invention illustrated in thedrawings, the section A is the uppermost body section and is tubular, while the section B is the lower section and extends into the lower end of the section'A. The upper section A is adaptedl to be connected with the lower end of the operating string S, while the section B is adapted to be connected with the shing tool T for engaging the lost part or fish F. In the particular case illustrated in Fig. 1 of the drawings, the body section B is connected with the tool T through a length of drill pipe P and suitable connecting members.

The body section A is hollow or tubular and forms a housing for the principal portions of the tool. In the preferred construction, the section A includes an upper section or part I3, and a lower part I4. The upper part I3 is provided with a central longitudinal opening I5 ,an'd a screw threaded pin I6 at its lower end. The lower end portion of the opening I5 is of restricted diameter to provide an upwardly facing internal shoulder I1 in the body part I3. In accordance with the invention, the upper end of the body part I3 is connected with the operating string S through a lrotatable and releasable connection. A top sub or connecting member I8 is rotatably and releasably attached to the upper end of the body part I3. In the particular case illustrated in the drawings, the member I8 is screw threaded into the upper end of the part I3. The threads connecting the part I3 and the member I8 are preferably right hand threads.l A socket is provided in the upper end of the connecting member I 8 to receive the threaded pin of a tool joint, or the like. A central longitudinal fluid passage or opening 20 is provided in the member I8. The lower body part I4 of the section A is screw threaded on the pin I6. The part I4 is a tubular member having a central longitudinal opening 2l. A portion of reduced internal diameter is provided at the lower end of the body part I4 to provide an upwardly facing internal shoulder 22. The shoulder 22 is in the nature of a hammer face or jar shoulder for cooperating with a shoulder on-the section B to provide the jarring blow when the means II is released.

The section B extends into and is slidable longitudinally in the opening 2| of the lower body part I4. A screw threaded pin 23 is provided on the projecting lower end of the section B to connect with a coupling 24 on the upper end of the portion of pipe P. A central longitudinal fluid passage 25 extends through the section B from one end to the other. In accordance with the invention, means is provided for holding the main sections A and B against relative rotation. In the particular case illustrated in the drawings, splines or keys 26 are provided on the section B to cooperate, with the key-ways 21 in the lower part I4 of the section A. A downwardly facing anvil shoulder 28 is provided on the section B. The shoulder 28 is spaced above the shoulder 22 when the means II is holding the sections A and B in the contracted lposition and is engaged or struck by the shoulder 22 when the means I I is released. Packing 29 may be provided in an annular groove 3D in the section B to seal with the walls of the opening 2 I.

The stern I0 is slidably connected with the section A and is normally releasably connected with the section B by the clutch means II. The stem IIJ extends centrally through the upper section A and its upper end is slidable in the opening 20 of the member I8. Packing 3I is provided in a groove in the walls of the opening 20 to seal with the stem I0. The stem II] is also slidable in the opening in the pin I6 and packing 32 is provided in the pinto seal with the stem. The stem II! is tubular, having a central longitudinal opening 33 for passing circulation fluid from the connecting member I8 to the section B. In accordance with the invention, means is provided for holding the stem I0 against rotation relative to the connecting member I8. Pins 34 are threaded in diametrically opposite openings 35 in the member I8 and extend into longitudinal slots 36 in the upper end of the stem. Plugs 31 may close The means II includes a yielding member 38' yieldingly resisting upward movement of the section A relative to the stem I0 and clutch or latch members 39 on the section B, for cooperating with the stem I0 to releasably hold the stem against upward movement relative to the section B.

The yielding member 38 is arranged between the shoulder I1 of the section A and a nut 4U on the stem Ill. The member 38 is adapted to yield or compress under a Very heavy compression strain. In accordance with the invention, the member 38 is a single piece or body of hardened steel. The member 38 is tubular, surrounding the stem I D and is corrugated or grooved so as to yield under compression. Longitudinally spaced annular grooves 4I are provided in the interior of the member 38 anda plurality oi longitudinally spaced annular grooves 42 are provided in the exterior of the member. The grooves 4I are longitudinally staggered or offset with relation to the grooves 42 so that the member 38 is of corrugated cross section. When the clutch members 39 are in cooperation with the stem I0 and a heavy up-strain is put on the section A, the member 38 is compressed between the shoulder I1 and the nut 43. When the up strain or tensile strain becomes suiliciently heavy, the member 3S yields or compresses slightly to permit upward movement of the section A relative to the stem IIJ and section B.

v The clutch members or latch members 39 are pivotally or tiltably connected to the section B and have releasable latching or clutching engagement with the stem I0. In the particular embodiment of the invention illustrated in the drawings, there are four like or identical latch members 39. The latch members 39 are arranged in the opening 2i and are tiltably connected with the upper end oi the section B. A

reduced head 44 having a downwardly facing annular shoulder 45 is provided on the upper end of the section B. The latch members 39 are arcuate in cross section to t or engage about the head 44 and each member 39 has an upwardly facing shoulder 46 to cooperate with the shoulder 45. The cooperation of the shoulders 46 with the shoulder 45 positively holds the latch members39 against longitudinal movement relative to the section B. The head 44 and the lower end portions of the latch members 39 are bevelled to permit tilting of the latch members 39 between the positions illustrated in Figs. 3 and 5 of the drawings.

Teeth 41 are provided on the interiors of the latch members 39 to cooperate with longitudinally spaced annular teeth 48 on the stem. The

teeth

41 and 48 are adapted to cooperate to releasably hold the stem I and accordingly the section A against upward movement relative to the section B. The upper and lower faces of the teeth. 48 are bevelled outwardly as illustrated throughout the drawings and the teeth 41 are shaped to effectively cooperate with the teeth 48. Theupper faces of the teeth 48 and the lower faces of the teeth 41 are but slightly tapered so that the teeth are effective in preventing longitudinal movement between the sections A and B when the latch members 3,9 are held in against the stem I9 in the manner hereinafter described. The several teeth 48 of the stern I9 are progressively narrower or shorter from the upper end of their series to the lower end of the series to compensate for pivotal movement of the latch members 39 so that all of the teeth 41 may be simultaneously disengaged from the teeth 48.

The invention includes means for normally holding the upper ends of the clutch members or latch members 39 in against the stem I8 so that the

teeth

41 and 48 are in engagement. The means for holding the upper ends of the latch members 39 in against the stern Ill releases the members 39 for outward movement upon yielding of the member 38 andthe resultant upward movement of the section A relative to the section B. A cage or sleeve 49 surrounds the stem I and is slidable in the upper end portion of the opening 2l. The sleeve 49 is slidable'on an enlargement 90 on the stem II). The upper end of the enlargement 99 forms a shoulder 9I adapted to engage the lower end of the pin I6 to limit upward movement of the stern relative to the section A during actuation and resetting of the tool. The lower end of the sleeve 49 normally rests on an upwardly facing shoulder I) on the walls vof the opening 2l and is yieldingly held against the shoulder by a spring 5Ia. The spring 5IF- may be in the nature of a helical spring arranged under compression between the lower end of the pin IB and the sleeve 49. An annular recess 5I is provided in the lower end of thesleeve 49 to receive the upper ends of the several latch members 39. The walls of the recess 5I are adapted to hold the latch members 39 in against the stem IU so that the

teeth

41 and 48 arel maintained in cooperation.

Upon comparatively slight upward movement of the section A relative to the section B the sleeve 49 also moves upwardly so that the upper ends of the latchmembers 39 pass out of the recess 5I. The cooperation of the bevelled

teeth

41 and 48 causes the latch members 39 to move or pivot outwardly upon disengagement of the sleeve 49 from the upper ends of the .latch members. It will be apparent that disengagement of the latch members 39 from the stem I0 permits upward movement of the section A relative to the section B so that the shoulder 22 is brought into jarring engagement with the shoulder 28. In practice, a very heavy tensile strain must be put on the sections A and B through the operating string S before the member 38 yields sufficiently to cause the sleeve 49 to move upwardly out of engagement with the latch members 39 so that the operating string S is stretched to a considerable extent. The heavy tensile strain together with the elasticity of the stretched or elongated operating spring S insures a very heavyupward jarring action when the shoulder 22 strikes the shoulder 28.

It is to be particularly noted that upon the sleeve 49 uncovering the upper ends ofthe latch members 39, the bevelled sides of the

teeth

41 and 48 cooperate to cause the members 39 to suddenly and simultaneously move outward away from the stem I8. This sudden or instantaneous release of the means II, puts a minimum of wear `and friction/ on Athe latch members and the toothed portion of the stem I0. .W

lIt is a feature of the invention that the releasable holding means II may be reset or re-engaged when the tool is in the well bore. The lower end 53 of the sleeve 49 is bevelled downwardly and outwardly. After actuation of the tool the operating string may be lowered or permitted to settle to move the section A downwardly relative to the section B. Downward movement ofl the section A brings the lower end 53 of the sleeve 49 into camming engagement with the/upper ends of the clutch members 39, forcing the upper ends of the clutch members into the recess 5I. Fig. 5 of the drawings illustrates the upper ends of the latch members in engagement with the lower end 53 of the sleeve 49. The spring 5I is operable to yield during such engagement of the upper ends of themembers 39 with the sleeve 49 to permit the teeth 41 to move into proper engagement with the teeth 48 and allow the upper ends of the members 39 to pass into the recess 5I through their cooperation with the face 53. The spring SIB-is also operable to return the sleeve 49 to its normal down position in engagement with lthe shoulder 5I] after passage of the upper ends of the members 39 in the recess 5I. Plugged openings 54 may be provided in the walls of the body part I4 through which suitable tools may be passed to move the sleeve 49.upward1y out of engagement with the latch members 39 if it is desired' to manually trip the tool.

The means I2 is operable through manipulation of the operating string S to adjust or regulate the tool to trip when under tensile strains of different intensities. In accordance with the invention, the means I2 is in the nature of a mechanical adjusting means that is operable upon turning of the connecting member I8 to cause the means II to release under different tensile strains. The means I2 includes a threaded connection between the nut 49 and the stem I0. In practice the threads 55 connecting the nut 40 with the stern I0 have a comparatively `heavy pitch and may be left handv stern I0 causes the threads 55 to shift the stemv I 58 may turn through an arc of about 130. Stop lugs 68 project upwardly from the upper end of the clutch member 58. There are two lugs 60 at diametrically opposite sides of the vertical axis of the member 58. The sides of the lugs 60 are Vertical andrradial. Similar diametrically Vspaced lugs 6 I 'project downwardly from the lower end of the member I8 to cooperate with the Vlugs 60.

A spring 82 is arranged under compression between the nut 40 and the clutch member 58 toyieldingly hold the clutch member in an up position where its lugs 80 are adapted to cooperate with the lugs 6I. The keys 56 terminate at points where they do not interfere with the turning movement of the lugs 6I. The lugs 6U and 6I are positioned and related so that the connecting member I8 may be turned about 90 relative to the clutch member 58 and therefore relative to the section A, before and without causing turning of the clutch member 58. The connecting member I8 may be turned further together with the clutch member 58 which may be turned about 180.

With the connection just described, it will be seen that the connecting member I8 may be turned the major portion of a revolution relative to the section A. The turning of the member I8 relative to the section A causes corresponding turning of the stem I0 so that the stem is threaded either up or down through the nut 40 depending upon the direction of turning of the member I8. Longitudinal adjustment of the stem I causes corresponding adjustment of the clutch members 39 relative to the section A and retaining sleeve 49. It will be seen that adjustment of the latch members 39 when in holding engagement with the stem I0 relative to the sleeve 49 permits the latch members to move out of the recess I upon the member 38 yielding under compression strains of different intensities. In this manner the tool may be regulated or adjusted to trip or operate under different pre-determined tensile strains. Openings may be provided in the walls of the body part I3 to permit the lock member 58 to be moved downwardly by suitable tools to disengage its lugs 60 from the lugs 6I. The pins 34 may be threaded out and disengaged from the slot 36 so that the member I8 may be turned without causing turning of the stem I0. When the pins 34 extend into the slot 36 the connecting member may be turned in one direction to adjust the stemx I0. The pins 34 may then be disengaged from the slot and the member I8 turned in the other direction to return it to its original position where the pins may be re-engaged in the slot to provide for further adjustment of the stem and thus provide for a wide range of adjustment of the tool. In this manner the tool may be regulated or adjusted at the surface to operate under tensile strains within a given range and may again be adjusted when in the well bore to trip under a certain tensile strain within the chosen range.

It is believed that the operation of the tool provided by the present invention will be readily apparent from the foregoing detailed description. As just set forth, the tool may be adjusted to `the surface to'trip or operate under tensile strains Within a known range. When the tool is in the well bore, the operating string S may be turned to cause corresponding turning of the connecting member I8 and stem III. Due to the loose mounting of the lock member 58 and the relationship of the lugs 60 and 6I, the connecting member I8 and stem I 0 may be turned the major portion of a revolution in either direction. Turning of the stem I0 causes threading of the stem I0 longitudinally in the tool and corresponding relative movement between the sleeve 49 and the upper ends of the latch members 39. The sleeve 49`may in this manner be moved out of holding engagement with the clutch members 39 upon the sections A and B being subjected to tensile strains of different strengths under which the member 38 yields different amounts. Upon disengagement of the sleeve 49 from the latch members 39 the latch members move outwardly permitting sudden upward movement of the stem I0 and section A bringing the shoulder 22 into hammering engagement with the shoulder 28. The tool may be quickly reset for operation by moving the section A downwardly relative to the section B to bring the sleeve 49 into holding engagement with the upperl ends of the latch members 39.

It will be noted that the present invention provides a jarring tool that may be adjusted when in the well bore to provide jarring blows of different strengths or intensities. The adjusting means I2 is such that simple turning of the operating string S when not under tension, provides for the desired adjustment. The tool is simple and easy to operate and does not interfere with nor depend for its actuation or adjustment upon the circulation of fluid through the operating string and fish.

Having described only a typical preferred form of my invention, I do not wish to limit myself to the specific details set forth, but wish to reserve to myself any changes or 'variations that may appear to those skilled in the art or fall Within the scope of the following claims:

Having described my invention, I claim:

1. A jarring tool for use in an operating string in a well including, two sections connected for limited relatice longitudinal movement, means in one of the sections for releasably holding the sections against relative longitudinal movement operable to release the sections for relative movement upon a tensile strain being put on the sections, and means for adjusting the said means to release under different tensile strains including a member rotatably connected with said section and adapted to be attached to the operating string, a stem connected with the member for rotation therewith and to be slidable relative thereto,'and a nut in said section through which the stem is threaded.

2. A jarring tool for use in an operating string in a well including, two sections connected for limited relative longitudinal movement, means in one of the sections for releasably holding the sections against relative longitudinal movement operable to release the sections for relative movement upon a tensile strain being put on the sections, and means for adjusting the said means to release under different tensile strains including a member rotatably connected with said section and adapted to be attached to the operating string, a stem associated with said means and connected with said member for rotation therewith and to be longitudinally movable relative thereto, a part in said section through which the stem is threaded, and means limiting rotation of the stem.

3. A jarring tool for use in an operating string in a well including, two sections connected for limited relative longitudinal movement, means in one of the sections for releasably holding the sections against relative longitudinal movement operable to release the sections for relative movement upon a tensile strain being put on the sections, and means for adjusting the said means to release under different tensile strains including a member rotatably connected with said section and adapted to be attached to the operating string, a stem associated with said means and connected with said member for rotation therewith and to be longitudinally movable relative thereto, a part in said section through which the stem is threaded, a part having limited rotation relative to the section, and means limiting rotation of the said member relative to the last mentioned part.

4. A jarring tool including two sections related for limited relative longitudinal movement, a stem in one section, a yieldable member mounting the stem on said section, a clutch member carried by the other section for cooperating with the stem, and a part on the first mentioned section normally engaging the clutch member to hold the -clutch member in cooperation with the stem and disengagable from the clutch member upon yielding of said member.

5. A jarring tool including, two sections related for limited relative longitudinal movement, a stem in one section, a yieldable member mounting the stem on said section, teeth on the stem, a toothed clutch member connected with the other section and adapted to cooperate withthe teethtoholdthe sections against relative longitudinal movement, and a part on the inst-mentioned section normally engaging the clutch member to hold the clutch member in cooperation with the teeth on the stem and disengageable from the clutch member upon a predetermined yielding of said member.

6. A jarring tool including, two sections related for limited relative longitudinal movement, a stem in one section, a yieldable member mounting the stem on said section, a clutch member' tiltably connected to the other section operable to cooperate with the stem to hold the sections against relative longitudinal movement, andacage on the rst mentioned section for holding the clutch member in cooperation with the stem and releasable from the clutch member upon a predetermined yielding of said member.

7. A jarring tool including, two sections related for limited relative longitudinalmovement, a stern in one section, a yieldable member mounting the stem on said section, teeth on the stem, a clutch member for cooperation with the teeth to hold the sections against relative longitudinal movement, a cage on the said section for holding the clutch member in cooperation with the teeth and movable out of holding engagement with the clutch member upon a certain yielding of the yieldable member, and means for adjusting the stem longitudinally of the sections whereby the cage is releasable from the clutch member upon the yielding member yielding diierent extents.

3. A jarring tool including, two sections related for limited relative longitudinal movement, a stem in one section, a yieldable member mounting the stem on said section, teeth on the stem, a clutch member for cooperation with the teeth to hold the sections against relative longitudinal movement, a cage on the said section for holding the clutch member incooperation with the teeth and movable out of holding engagement with the clutch member upon a certain yielding of the yieldable member, and means for adjusting the stem longitudinally of the sections whereby the cage is releasable from the clutch member upon theV yielding member yielding different extents, including a nut threaded on the stem and mounting the stem on said section through the yielding member,

9. A jarring tool including, two sections related for limited relative longitudinal movement, a stem in one section, a yieldable member mounting the stem on said section, teeth on the stem, a clutch member for cooperation with the teeth to hold the sections against relative longitudinal movement, a cage on the said section for holding the clutch member in cooperation with the teeth and movable out of holding engagement with the clutch member upon a certain yielding 5 of the yieldable member, and means for adjust-f ing the stem longitudinally of the sections whereby the cage is releasable from the clutch member upon the yielding member yielding dierent extents, including a nut threaded on the stem and mounting the stem on said section through the yielding member, and means for turning the stem.

l0. A jar including, two sections related for. limited relative longitudinal movement, means for releasably holding the sections against relative longitudinal movement, including a toothed stem yieldingly carried by one section, and a plurality of toothed latch members connected with the other section and cooperating with the stem, and a member carried by the rst mentioned section normally holding the clutch members in cooperation with the stem and releasable from the stem upon the sections being subjected to a given tensile strain. 25

11. A jarring tool for use in connection with an operating string in a well bore including two sections related for limited relative longitudinal movement, means, for releasably holding the sections against relative longitudinal movement including a part having an adjustable connection with one section and an element connected with the other section and adapted to have re leasable holding cooperation with the said part, the part and element being disengageable upon a tensile strain being put on the sections, and a member directly connected to the operating string and operable upon manipulation of the operating string to adjust said adjustable connection whereby the said part and element may 40 disengage under various tensile strains.

12. In combination, an operating string to extend into a well, and a jarring tool connected to the operating string including two sections related for limited relative longitudinal movement, and means for holding'the sections against relative longitudinal movement releasable upon a tensile strain being put on the sections, said means including apart having an adjustable connection with one of the sections, the said 0 means being releasable under different tensile strains upon adjustment of said part, a member operatively connected with said part to adjust said part upon being manipulated, and means directly connecting the member with the operating string so that said part is adjusted by manipulation of the operating string.

13. In combination, an operating string to extend into a well, and a jarring tool connected to the operating string including two sections related for limited relative longitudinal movement, and means for holding the sections against relative longitudinal movement releasable upon a tensile strain being put on the sections, said means including a part having an adjustable connection with one of the sections, the said means being releasable under different tensile strains upon adjustment of said part, a member operatively connected with said part, means rotatably connecting the member with one of the sections, means for attaching the member to the operating string so that the member forms a connector between the operating string and l the section and whereby vsaid part may be adjusted by turning of the operating string. A

14. A jarring tool for use in connection with an operating string in a well bore including two sections connected for limited relative longitudinal movement, means for rotatably connecting one of the sections with the operating string, means for holding the sections against relative longitudinal movement releasable upon a strain being put on the sections, and means actuated by turning of the operating string relative to said section to adjust the last mentioned means to release upon strains of different intensities being put on the sections.

15. Apparatus for jarring an object in a Well including an operating string for extending int-o the well, two sections connected for limited relative longitudinal movement, means associated with one section for engaging the object in the Well, means for connecting the other section with the operating string comprising a member attached to the operating string, and a rotatable connection between the member and the said other section, means for holding the sections against relative longitudinal movement releas'able by a strain on the sections, and means for adjusting the last mentioned means governed by rotation of the operating string relative to said other section.

' IRA J. MCCULLOUGH.