US3096824A

US3096824A - Gripping devices

Info

Publication number: US3096824A
Application number: US769189A
Authority: US
Inventors: Cicero C Brown
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-10-23
Filing date: 1958-10-23
Publication date: 1963-07-09
Anticipated expiration: 1980-07-09

Description

C. C. BROWN GRIPPING DEVICES July 9, 1963 Filed 001'.. 25,' 1958 3 Sheets-Sheet 1 all! DI f r C. C. BROWN GRIPPING DEVICES July 9, 1963 3 Sheets-Sheet 2 Filed Oct. 23, 1958 CICERO C'. BROWN INVENTOR. mCL/Lm/ g grada/141A 4TTORNEYS C. C. BROWN GRIPPING DEVICES July 9, 1963 5 Sheets-Sheet 3 Filed 001;. 23, 1958 c/c'E/Po c: feow/y INVENTOR.

IAM 67' ILJGMA 7n, hl' M Arme/VIE Ys 3,096,824 GRIPPING DEVICES Cicero C. Brown, 8490 Katy Road, Houston, Tex. Filed Oct. 23, 1953, Ser. No. 769,189 17 Claims. (Cl. 16d-210) This invention relates to new and useful improvements in gripping devices.

r[The invention is particularly adapted for use with well tools and apparatus, such as well packers, wherein it is necessary to hold one portion of the tool against movement while another portion thereof is moved, as, for example, in setting `and releasing a well packer.

The usual type of device for performing this function is generally known as a friction shoe or friction spring assembly in which a frictional contact between a shoe element or spring and the wall of the casing or well bore is depended upon to hold a desired part against movement. If the frictional contact is strong enough to accomplish the purpose of holding the assembly, then difficulty is experienced in lowering the tool into the well because of the excessive frictional resistance; on the other hand, if the frictional resistance to lowering is reduced by reducing the force of frictional contact, no assurance is had that proper operation of the tool will be accomplished when the lowering pipe is manipulated.

It is, therefore, one object of this invention to provide an improved gripping device which lmay be substituted for .the usual friction shoe or spring assembly of a well tool and which overcomes Iall of the disadvantages thereof in that it may be readily lowered without offering any resistance to such lowering and yet may be easily actuated to positively and firmly engage the wall of the pipe or bore when it is desired to lock a portion of the tool on which it is mounted against movement.

An important object is to provide an improved gripping device having wall gripping elements which are displaced outwardly into gripping position by a simple manipulation of the member upon which the device is mounted, the device including a cam-type actuator which exerts a positive outward force upon the elements to assure their movement into tight gripping position.

Still another object is to provide a gripping device, of the character described, wherein arcuate gripping elements are mounted upon `a support in such manner that said gripping elements normally engage the wall of the well pipe or bore with relatively light frictional contact, said elements being movable into tight gripping position by a rotation of the support on which the device is mounted and being maintained in such iirm gripping position until the support is again manipulated.

A further object is to provide a gripping device which may be combined with a well packer or other tool or which, if desired, may merely mount upon a well pipe to function vas an anchor to lock said pipe against movement in a Well bore.

The construction designed to carry out the invention will be hereinafter described, together with `other features thereof. Y

The invention will be more readily understood from a reading of the following specilication and by reference to the accompanying drawings, forming a part thereof, wherein an example of the invention is shown and wherein: l

FIGURE 1 is a view, partly in section and partly in elevation of a gripping device constructed in accordance with the invention` and showing said device combined with the anchoring means of a well packer, said device being in a normal or non-gripping position;

FIGURE 2 is a similar view with the gripping device actuated and the packer in set position;

FIGURES 3, 4 and 5 are horizontal cross-sectional 3,096,824 Patented July 9, 1963 views, taken on the lines 3 3, 4 4 and 5 5, respectively, of FIGURE l;

FIGURE 6 is a horizontal cross-sectional view .taken on line 6 6 of FIGURE 1 with the gripping elements of the device in a normal, non-gripping position;

FIGURE 7 is a similar view, taken on the line 7 7 of FIGURE 2 with lthe elements in firm gripping position;

FIGURE 8 is a longitudinal sectional view of the gripping device mounted upon a Well pipe for anchoring said pipe within a well bore;

FIGURE 9 is a horizontal cross-sectional View similar to FIGURE 6 but illustrating `a gripping device having three gripping elements;

FIGURE 10 is ya horizontal cross-sectional view similar to FIGURE 7 but illustrating a gripping device having three gripping elements; and

FIGURE 1l is a partial sectional View similar to FIG- URE 1 but illustrating the gripping device connected with the expander cone rather than the gripping slips of Vthe Well packer.

In the drawings the improved gripping device which is generally indicated by the letter A has been shown in FIGURES 1 and 2 as used with a well packer; in FIG- URE 8 the device A is merely applied to a pipe or support for the purpose of lanchoring the same within another pipe, such as a well casing. It is pointed out that the illustrations of the particular use of the invention are exemplary only and, as will hereinafter appear, the device may be employed in any environment where it is desired to maintain a member against movement Within a pipe `or Well bore.

Referring to FIGURES 1 and 2, the gripping device A of this invention is mounted at the lower end of a Well packer P. The packer may be of any desired construction but as shown includes a central tubular support or mandrel having its upper end connected through `a coupling 11 with a well tubing or lowering pipe 12. An annular flexible packing element 13 surrounds the mandrel and below said mandrel an annular slip expander or cone 14 is mounted; the cone may be limited against downward movement on the mandrel by means of a shoulder 15.

Arcuate wall engaging members 16, which are shown in the form of the usual gripping slips, surround the expander cone 14 and also surround the mandrel 10 as is clearly illustrated in FIGURE l. The vrear surfaces of the members or slips 16 are provided with projections 17 which fit within retaining grooves 1S in the cone whereby outward displacement of the slips from the cone or eX- pander is prevented. As is usual in gripping slip assemblies of this character, the relative movement of the cone 14 with respect to the gripping slips 16 will, due to the inclined co-acting surfaces of these parts, cause a radially outward movement of the slips whereby said slips may engage the wall of the well casing C. When the slips are in their lowered position with respect to the cone (FIG- URE `1), said slips are retracted, but when moved upwardly along the surface of the cone (FIGURE 2), said slips are engaged.

As is well known in the well packer art, the gripping slips are normally in their retracted position While the packer is lowered within the well casing. Upon reaching the desired position at which the packer is to be set, it is necessary that the slips 16 be released for upward movement relative to the expander or cone 14 and the usual type of packer employs a friction spring assembly which is connected with the slips and which is also connected to the mandrel through a J-slot connection. The disadvantages of the usual friction spring assembly are that if the springs are strong enough to support the slip assembly when it is desired to set the packer, they present an objectionable resistance to lowering. If made so as to engage the wall only with a light frictional resistance during lowering, the friction springs may not be sufficient to support the slips and assure proper setting.

In place of the usual friction spring assembly, the gri ping device A is mounted on the lower end of the mandrel or support 10. f course, the device A could include its own mandrel or support which would have threaded connection with and form a continuation of the packer support 10. Sur-rounding the support is a tubular sleeve 2d having an enlarged collar 2d at its lower end. The collar 21 is secured to the lower end of the sleeve 2i) by radially extending pins 22 (FIGURE 5) which are threaded into the collar and which extend through openings 23 in the sleeve 20.

The upper end of the tubular sleeve 2o is formed with a lateral or annular ange 24 whi-ch preferably has the same radial projection as the collar 21. As shown in FIGURES l and 2, the lower surface of the ange 24 is spaced from the collar 21 and gripping elements G, which will be hereinafter described in detail, are disposed within this space.

For connecting the tubular sleeve 20 of the gripping device A with the gripping slips 16, the flange 24 is formed with upwardly connecting lugs 25 which are engageable within recesses 26 in the lower external portion of the gripping slips 16. It is thus obvious that the tubular sleeve 20 and its associated parts have a direct connection with the gripping slips 16 and when the sleeve 2o is held stationary, the slips 16 are also held stationary. Although the lugs 25 and recesses 26 provide a simple manner of attachment between the device A and said slips, any other suitable means may be employed.

For attaching the tubular sleeve 20 of the gripping device A to the mandrel or support, the inner ends of the pins 22, which, as explained, are secured to the collar and sleeve, are adapted to engage within J-slots 27. The J- slots are diametrically opposed and are formed in the external surface of the mandrel or support 1%'. When the pins 22 are in the lateral portions 27a of the J-slots 27, upward movement `of the sleeve 20 and of the gripping slips 16 connected therewith with respect to the mandrel or support is prevented. Therefore, at this time the gripping slips 16 can not mov-e upwardly with respect to the expander 14, the parts being in the position shown in FIGURE 1.

When the support or mandrel is rotated by means of the tubing or lowering pipe 12, the J-slots 27 may turn with respect to the pins 22 so that said pins may align with the vertical portion 27b of the J-slots 27. Thereafter, the support or mandrel 10, which also carries the expander 14, may be moved downwardly with respect to the tubular sleeve 2t) of the device A and with respect to the gripping slips 16 connected therewith. As the expander moves downwardly, the gripping slips '16 will be moved outwardly into gripping engagement with the pipe as shown in FIGURE 2 and thereafter the imposition of weight of the support pipe upon the flexible packing element 13 will expand the same into sealing position.

In the particular packer shown, upper auxiliary holddown means 28 are mounted in the coupling member 11. These means are in the form of holddown buttons 23 and each is mounted within a recess 29, The rear surface of each button is exposed through ia port 29a to the pressure within the bore of the support. A coil spring 31 normally holds each button 'in retracted position until the pressure acting against the button is sufficient to urge the same into gripping position.

From the foregoing it will be evident that when the packer is to be set, the support ll` having the J-slots 27 therein must undergo a rotation with respect to the gripping device A; also, it is necessary that the gripping slips 16 be held stationary within the well casing C to permit the subsequent downward movement of the support and the expander cone 14 with respect to the slips. To assure that the gripping device A will hold the slips against movement, the gripping elements G are provided. Each gripping element is in the form of a generally semicircular shoe 30 (FIGURES 6- and 7), which substantially encircles one-half of the tubular sleeve 2t). The lower end of each shoe has a depending iiange 31 which coacts` with an upstanding iiange 21a on the collar 21 while the upper end of the shoe has a fange 32 co-acting with a depending projection 24a on the ange 24; it will be evident that the

flanges

31 and 32 limit the outward movement of the shoe with respect to the tubular sleeve.

Each arcuate shoe 3) has an enlarged contact portion 33 and the central louter surface 33a of this portion is substantially smooth to provide a non-gripping area which frictionally engages the wall of the well casing C. Gripping surfaces such as gripping teeth 3317 and `33C are formed .on each side of the non-gripping surface 33a in the manner illustrated and Ieach set of gripping teeth is spaced from the wall of the casing C when the smooth non-gripping surface is contacting said casing which is the position shown in FIGURE 6. Normally the shoes are placed around the sleeve 20 and are urged outwardly so that their respective non-gripping surfaces 33a slidably engage the wall of the well casing by coil springs 34, the ends of said springs being mounted within recesses 35 in the free ends of each shoe. Said free ends of the shoes are spaced lfrom each other to allow independent movement with respect to each other. `It is pointed out that the springs 34 are relatively weak and are only sufficient to urge the non-gripping surfaces of the shoes 30 into contact with the wall of the pipe with a relatively light friction. The frictional force should only be sufficient to prevent the shoe elements 30 from rotating. This light frictional contact permits the device A to be lowered downwardly through the well casing without presenting any great resistance to such lowering.

For the purpose `of effecting a gripping engagement of each shoe 30 with respect to the wall of the casing in order to assure that the gripping slips 16 connected with the device will be held against movement, each gripping shoe has the internal surface of its enlarged portion 33 inclined to form cam surfaces in the manner indicated at 36 and 37. These inclined cam surfaces are adapted to co-act with a cani-type projection 38 which is provided on the external surface of the sleeve 20. As is clearly shown in FIGURE 6, two diametrically opposed projections 38 are provided and these projections are normally located as shown in this figure with respect to the

inclined surfaces

36 and 37 of the arcuate shoes 30.

In the operation of the gripping device the parts are in the position shown in FIGURES 1 and 6. At this time the pins 22, which are carried by the collar 21 and sleeve 20 of the device, are engaged in the lateral portion 27a of the J-slots 27. The light coil springs 34 are urging the arcuate gripping elements or shoes `30` radially outwardly and are maintaining the smooth non-gripping surface 33a of each shoe in light frictional contact with the wall of the well casing; at this time the gripping surfaces 33b and 33e are in spaced relationship to the wall of the well casing C. Thus, the well packer P may be lowered downwardly through the well casing to the point at which it is to be set and gripping slips 116- 0f the packer, which are connected with the device A, can not move to a set position.

When the point at which the packer is to be set is reached, the support or mandrel 10` is rotated to the right by means of the lowering pipe or well tubing 12. Such rotation will cause the cam projections 38 on the sleeve 20 to move into contact with the inclined surface 37 off the respective shoes 30 in the manner illustrated in FIG- URE 7. As each cam contacts the adjacent inclined surface 37 of the shoe, the shoe will undergo a slight rocking motion in a circumferential path and this will cause the teeth 3317 of each shoe to firmly engage the wall of the well casing. The rocking action is effected by reason of the initial slight clearance or spacing between the gripping surfaces 33b and 33e and the ywall of the casing C by reason of the angle of contact between the cam-type projection and the cam surface, which latter applies a radial force resulting in a combined rocking and radial shifting of the shoe suflicient to engage the gripping surface 331? with the pipe Wall. The rocking motion is assured because the smooth nongripping surface 33a is in contact with the wall at the time force is first applied so that, in effect, said smooth surface provides the pivotal point about which rocking can take place.

Contact of the gripping teeth l33b with the casing sets up a irrn gripping engagement between the shoe and the casing and, obviously, since the cam projections 38 are formed on the sleeve 20, lfurther rotation of the sleeve will be impossible. The sleeve 20 is thus iirmly anchored against any longitudinal or further rotational movement. The inner mandrel l is then lifted slightly so that the pins 22 (connected to the sleeve 20 and collar` 21) are located at or near the bottom of the lateral portions 27a of the J-slot 27 (formed in the mandrel i10) rIhe pins 22 are thus clear of the depending portion or lip on the mandrel 10 formed between the portions 27a and the relatively longer vertical portions 27b of the J-slot, and continued right-hand rotation of the mandrel 10 while the pins 22 remain anchored or stationary will move the portions 27h of each J-slot 27 into alignment with their respective pins 22. Thereafter, the support and its associated parts including the expander 14 may be lowered relative to the anchored device A and relative to the gripping slips 16 which are connected therewith. The positive engagement of the gripping elements or shoes 30 with the wall off the well casing will assure that the pins 22 may be properly aligned with the vertical portion 2712 of the J-slots and will further assure that the gripping slips 16 will remain stationary While the expander 14 is lowered with respect thereto. Of course, after the slips 16 are set, the weight of the lowering pipe 12 is imposed upon the packing element to set said packer and the device A has no further function. Thereafter, the support could be rotated back to the left to return the shoes to the position of FIGURE 6 although this is not essential since the shoes may remain in the position of FIGURE 7 so long as the packer remains set.

When it is desired to remove the packer, the support or mandrel is lifted and then rotated to the left to return the connecting pins 22 into the lateral portions of the slots 27 and, of course, at that time the cam projections 3S on the sleeve return to the position of FIGURE 6 whereby the only frictional contact between the shoes 30 and the casing wall is that produced by the relatively light springs 35.

From the foregoing it will be seen that a simple and effective device is provided which may be lowered through the well pipe with a minimum of frictional contact with the wall of the pipe whereby the device will not intertere with the lowering operation. However, when it is desired that a firm engagement between the shoes 30 and the pipe wall be had, it is possible to actuate the shoes through the cam-type projections 38 and move said shoes into positive gripping engagement. This assures that the J-slot may be properly manipulated and that the slips will be maintained stationary to permit positive setting of the packer. It has been found that two generally semicircular shoe elements will be sufficient but it is within the scope of this invention to provide a greater number of gripping shoes as, for example, three or four segmental shoes may be provided and in such case each shoe would be actuated by its own cam-type projection. FIG- URES 9 and 1G illustrate the device A including three gripping elements 30 and the three coacting cam-type projections 3S. Also, although the device A has been shown and described as connected with the gripping slips 16, said device could be connected with an expander cone as illustrated in FIGURE 11; in such arrangement the slips 16 are carried by the support or mandrel and would 6 be moved relative to the expander to effect setting of the slips.

The device A is particularly useful with well packers or other well tools in which a J-slot connection is employed and wherein it is desirable to hold one part stationary while allowing movement of another part of said tool. However, it is also applicable for use as a pipe anchor and in FIGURE 8 such an application is shown. In this modification the device A comprises a central tubular sleeve element 120 which is lformed integral with an upper coupling 124 and a lower coupling 121. The gripping elements or shoes 30 are mounted between the

couplings

124 and 121 in the manner hereinbefore described. The central support or sleeve 120 is formed with the projections 38 (not shown). The pipe or tubing i112, which is to be anchored, is connected to the

couplings

121 and 124.

The operation of this modification is substantially as heretofore described. 'Ihe device A is connected in the pipe 112 in the manner shown, is lowered to position and at this time the gripping elements 30 are engaging the wall of the casing C with a light frictional engagement. By imparting a rotation to the sleeve 120, the 'cam projections thereon move with respect to the cam surfaces of the shoes 30, said shoes being maintained stationary by the frictional contact with the pipe wall. Through the cam action, as heretofore described, the shoes are moved radially outwardly into tight gripping position with the casing -wa-ll and so long as the cam projections are engaged with the cam surfaces, the pipe is anchored within the casing. It is noted that the provision of the

inclined surfaces

36 and 37 make it possible to set the gripping shoes 30 into tight contact with the casing by either right or left hand rotation of the sleeve of the assembly A. In the `case of right hand rotation, the cam projection 38 engages the inclined surface 37 of each shoe as shown in FIGURE 7; however, in the case of left hand rotation, the projection 38 would engage the surface 36. lIn either event the shoe 30 is caused to undergo a rocking motion along a circumferential path which results in a radially outward movement suiiicient to obtain the tight gripping contact between the shoe and the pipe Wall.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims Without departing from the spirit of the invention.

What I claim is:

l. A gripping device for anchoring a member against movement within a pipe including,

a sleeve adapted to be connected with the member,

a pair of gripping elements mounted on said sleeve for limited rotational movement between said elements and said sleeve,

each gripping element having a non-gripping surface and a gripping surface spaced circumferentially and radially inward therefrom for nonengagement with the wall of said pipe when said non-gripping surface is in engagement with said wall,

each gripping element having extremities adjacent the extremities of the other gripping element,

means mounting said gripping elements for radial movement with respect to the sleeve,

resilient means disposed between the adjacent extremities of said elements acting upon the elements and constantly urging said elements outwardly so that the non-gripping surface of each element is urged into light frictional engagement with the pipe,

the gripping surfaces of the elements being normally disengaged from said pipe,

and coacting means on the sleeve and on each gripping element,

said coacting means engaging each other when the sleeve is rotated with respect to said elements to move the gripping surfaces of the gripping elements into tight engagement with the wall of the pipe.

2. A gripping device as set forth in claim 1 wherein,

the gripping surface on each element comprises gripping teeth which are firmly engageable with' the wall of the pipe when said gripping surfaces of said elements are urged into tight engagement with said pipe Walls.

3. A gripping device as set forth in claim 1 wherein,

the coacting means comprises cam-type projections on the sleeve and cam surfaces on the interior of the gripping elements whereby engagement of said projections with said surfaces effects movement of the gripping elements.

4. A gripping device for anchoring a member against movement within a pipe including,

a support adapted to be connected with the member which is to be anchored,

a pair of generally semi-circular gripping elements encircling the support and mounted thereon for limited rotational movement relative thereto,

each element having a non-gripping area and a gripping surface spaced circumferentially and radially inward therefrom, for non-engagement with the wall of said pipe when said non-gripping area is in engagement with said wall whereby each of said gripping elements may pivot about its non-gripping area to move said gripping surface into engagement with said wall,

means mounting said elements for limited movement in a direction radially of the support,

resilient means interposed between adjacent ends of the gripping elements for normally urging said elements outwardly so that said non-gripping area of each element is in relatively light frictional contact with the wall of the pipe bore,

and coacting means on the support and on the inner surfaces of the gripping elements,

said coacting means being engageable with each other when the support is rotated relative to the gripping elements to impart a circumferential rocking movement to said elements to urge said gripping surface of said elements into tight anchoring engagement with the wall of the pipe.

5. A gripping device as set forth in claim 4, wherein the coacting means between the support and each gripping element comprises a cam-type projection and cam-type surface, one on said support and one on said element.

6. A gripping device for anchoring a member against movement within a pipe including,

a support adapted to be connected with the member,

a gripping element carried by the support and mounted on the exterior thereof for limited rotational movement relative thereto,

said gripping element having a non-gripping area and a gripping surface spaced circumferentially and radially inward therefrom for non-engagement with the wall of said pipe when said non-gripping area is in engagement with said wall whereby each of said gripping elements may pivot about its non-gripping area to move said gripping surface into engagement with said wall,

means mounting said gripping element for radial movement relative to the support,

resilient means normally urging the gripping element outwardly so that said non-gripping area of said element is in light frictional contact with the wall of the pipe,

and coacting means on the support and on the gripping element,

said coacting means being engageable with each other when the support is rotated relative to the element to impart a rocking motion to the gripping element to thereby move said gripping surface of said element into tight gripping engagement with the pipe wall.

7. VA gripping device as set forth in claim 6 wherein the coacting means comprises a cam-type projection and a cam-type surface, Yone on the support and the other on the gripping element.

8. The combination with a Well packer having anchoring means which comprises wall-engaging members and `an expander which is movable relative to said members to expand the same, of a gripping device associated with said anchoring means,

.said gripping device including a support,

means connecting lsaid support to one of said wallengaging members 4and said expander of said anchoring means,

a gripping element carried by the support and mounted for limited rotational movement relative thereto and for movement in a -radial direction with respect thereto,

said gripping element having a non-gripping surface and a gripping surface 4spaced circumferentially and radially inward from said non-gripping surface and from the surface of the pipe wall whereby said element may undergo limited rocking movement in a circumferential direction to engage said gripping surface with said surface of the pipe wall,

resilient means normally urging the gripping element outwardly so that said non-gripping surface of said element is in light frictional contact with the Wall of the well bore into which the packer is lowered,

and coacting means on the support and said gripping element,

said coacting means being engageable upon rotation of the support relative to the gripping element to impart a rocking motion to the element to move said gripping surface of said element into firm engagement with the bore wall and thereby anchor that one of said Wall-engaging members and said expander of the anchoring means to which the support is connected against movement in the well.

9. In a well packer, an anchoring means comprising gripping slips and an expander movable relative to the slips to expand the same into engagement with the wall of a well pipe into which the packer is lowered.

a gripping device below the anchoring means and including a support,

means connecting said support to one of said gripping -slips or said expander of said anchoring means,

a plurality of segmental gripping elements carried by the support and mounted for limited rotational movement between said gripping elements and said support and for movement in a radial direction relative to the support,

each of said gripping elements having a non-gripping surface and a gripping surface spaced circumferentially and radially inward from said non-gripping surface whereby said elements may undergo limited rocking movement in a circumferential direction about said non-gripping surface,

means for normally urging each of the gripping elements outwardly Iso thatsaid non-gripping surface of each element is in light frictional contact with the wall of the Well pipe,

and coacting means on said support and said gripping elements,

said coacting means being engageable upon rotation of the support relative to said elements to impart a rocking motion to the elements to move said gripping surfaces of said elements into firm gripping engagement with the pipe wall to thereby hold the lsupport and connected one of said gripping slips or expander of the anchoring means against movement within the well pipe.

l0. In a well packer, the combination as set forth in claim 9 wherein the coacting means comprises cam-type projections on the support land inclined surfaces on said gripping elements. n i

1l. A gripping device for anchoring a member within a well bore including,

a mandrel -connected with the member,

a gripping element mounted upon the mandrel for movement outwardly in contact with the wall of the well and mounted for limited rotational movement whereby the mandrel may be rotated with respect to the element,

said gripping element having a non-gripping `surface and a igripping surface spaced circumferentially and radially inward therefrom for non-engagement with the Wall of the well bore when said non-gripping surface is in engagement with said Wall,

means urging said gripping element radially outward so that the non-gripping surface of said element is in light frictional contact with said wall,

and coacting means on said mandrel `and said gripping element engageable with each other when the mandIel is rotated with respect to the element for urging the gripping surface of said element into tight frictional engagement with the wall of the bore to thereby anchor said mandrel and member therein.

12. A gripping `device as set forth in claim 1l wherein =and coacting means on said mandrel and said gripping element engageable with each other when the mandrel is rotated with respect to the element for urging the `gripping surface of said element into tight frictional engagement with the wall of the bore to thereby anchor said mandrel and member therein.

15. A gripping device for anchoring a member against movement with a pipe including,

'a support adapted to be connected with the member,

a gripping element carried by the support -for limited rotational movement relative thereto,

said gripping element having a non-gripping surface and a -gripping surface spaced -circumferentially land radially inward therefrom for non-engagement with said pipe when said non-gripping surface is in engagement with said pipe,

resilient means normally urging the gripping element in such a direction so that said non-gripping surface is urged into light frictional contact with the wall of the pipe,

and `coacting means on the support and on the gripping ele-ment,

-said coacting means being engageable with each other when the support is rotated relative to the element to move the gripping surface of said element into tight engagement with the pipe wall.

16. A gripping device `as set forth in claim 15 wherein the gripping surface of the gripping element comprises gripping teeth,

which teeth are firmly engageable with the wall of the pipe when said gripping surface of said element is urged into tight engagement with said pipe wall.

17. A gripping device as set forth in claim 15 wherein the coacting means comprises a cam-type projection and a cam-type surface,

one on the lsupport fand the other on the gripping element.

the gripping surface of the gripping element comprises gripping teeth, which teeth are iirmly engageable with the wall of the pipe when said gripping surface is urged into tight engagement with `said pipe wall.

13. A gripping device as set forth in claim 11 wherein the coacting means on said mandrel and said gripping element comprise a cam-type projection on one of said mandrel or said gripping element and a 4coacti-ng surface on the other of said mandrel or said gripping element.

14. A gripping device for anchoring a member within a well bore including,

ya mandrel connected with the member,

a gripping element mounted upon the mandrel for movement outwardly into contact with the wall of the Well and also mounted upon the mandrel for rotational movement relative thereto,

`said element having a non-gripping surface `and a `gripping surface spaced circumferentially and radial ly inward therefrom for non-engagement with said References Cited in the ile of this patent UNITED STATES PATENTS able contact with said Wall,

Claims

14. A GRIPPING DEVICE FOR ANCHORING A MEMBER WITHIN A WELL BORE INCLUDING, A MANDREL CONNECTED WITH THE MEMBER, A GRIPPING ELEMENT MOUNTED UPON THE MANDREL FOR MOVEMENT OUTWARDLY INTO CONTACT WITH THE WALL OF THE WELL AND ALSO MOUNTED UPON THE MANDREL FOR ROTATIONAL MOVEMENT RELATIVE THERETO, SAID ELEMENT HAVING A NON-GRIPPING SURFACE AND A GRIPPING SURFACE SPACED CIRCUMFERENTIALLY AND RADIALLY INWARD THEREFROM FOR NON-ENGAGEMENT WITH SAID WALL WHEN SAID NON-GRIPPING SURFACE IS IN ENGAGEMENT WITH SAID WALL, MEANS NORMALLY URGING SAID GRIPPING ELEMENT RADIALLY OUTWARD SO THAT SAID NON-GRIPPING SURFACE IS IN SLIDABLE CONTACT WITH SAID WALL, AND COACTING MEANS ON SAID MANDREL AND SAID GRIPPING ELEMENT ENGAGEABLE WITH EACH OTHER WHEN THE MANDREL IS ROTATED WITH RESPECT TO THE ELEMENT FOR URGING THE GRIPPING SURFACE OF SAID ELEMENT INTO TIGHT FRICTIONAL ENGAGEMENT WITH THE WALL OF THE BORE TO THEREBY ANCHOR SAID MANDREL AND MEMBER THEREIN.