US2207130A - Actuating and locking mechanism for gripping devices - Google Patents

Description

July 9, 1940. Q QT|$ 2,207,130

ACTUATING AND LOCKING MECHANISM FOP. GRIPPING DEVICES Filed April 25, 1938 5 Sheets-Sheet 1 July 9, 1940. C 91-15 2,207,130

ACTUATING AND LOCKING MECHANISM FOR GRIPPING DEVICES Filed April 25, 1938 3 Sheets-Sheet 2 yerberz C. Offs July 9, 1940. OTIS 2,207,130

ACTUATING AND LOCKING MECHANISM FDR GRIPPING DEVICES V Filed April 25, 1958 3 Sheets-Sheet 5 m "if" 31 vuc/rvtw Herbem C. Oil's Patented July 9, 1940 UNITED STATES arcane Parent QFFICE ACTUATING AND LOCKING MECHANISM FOR GRIPPING DEVICES Herbert G. Otis, Dallas, Tex.v

Application April 25, 1938, Serial No. 204,252

Claims.

In runningpipe, or tubing, into the well bore 10 under pressure, it is necessary to force, or pull,

the pipe downwardly into the hole and to accomplish this, equipment, generally referred to as snubbing equipment, is employed. The snubbing equipment usually consists of a travelling snubher, which grips the pipe and pulls the same downwardly into the bore against the closed well pressure, and a stationary snubber, which is employed to grip the pipe and prevent it from being blown from the well by the well pressure while the travelling snubber is being raised to take a new grip on the pipe. In other words, the travelling snubber grips the pipe and is moved downwardly to force the pipe into the well bore and during this time, the stationary snubber is inactive. When the travelling snubber reaches its limit of downward movement, the stationary snubber is engaged with the pipe to hold the same until the travelling snubber has been moved upwardly to take a new grip on the pipe. After the travelling snubber has again been engaged with the pipe, the stationary snubber is released and the operation repeated.

The usual stationary snubber employs pivoted gripping dogs which are adapted to be moved into gripping engagement with the pipe by means of a handle or operating member, which is relatively short inlength. The dogs must be held in engagement with the pipe while the travelling snubber is moved to a new position and this is usually done by one man who holds the handle in a proper position to maintain such gripping engagement. Since the handle, which operates the gripping dogs, is relatively short, a relatively small leverage is had, which makes it difficult 45 to exert sufiicient force on the dogs to move them into tight gripping engagement with the pipe.

It is, therefore, one of the objects of this invention to provide an auxiliary operating means for actuating the gripping elements of well snub- 50 bers, or other gripping devices, whereby operation of said device is made easier and may be accomplished more rapidly.

An important object of the invention is to provide an improved operating mechanism for the gripping dogs of well snubbers which is constructed so that the force exerted is amplified or increased, which facilitates actuation of the dogs by one operator, and which is provided with latching means for locking the mechanism in a position holding the dogs in gripping engagement with the pipe, whereby the necessity of one person holding said dogs in such position, is obvia ed.

Another object of the invention is toprovide an operating and locking mechanism for well snubbers, or similar gripping devices, in the form of an auxiliary handle or lever adapted to be connected with the usual operating handle of the device, such as shown in my Patent Re. 19,498; the mechanism being so constructed that it may be applied to the device without any materi'al change in the same.

A further object of the invention is to provide an improved mechanism, of the character described, wherein an auxiliary operating lever is pivotally mounted on the stationary well snubber and is connected with the usual handle thereof in such manner that said auxiliary handle may be utilized to positivelyactuate the dogs of the snubbers to either engage or retract said dogs from the pipe, or other element.

Still another object of the invention is to provide an improved actuating and locking mechanism for gripping devices wherein locking means is arranged to latch the actuator against movement from a position holding the gripping device in a gripping position; said means being so constructed that, when in latching position, it will not interfere with movement of the actuator in a direction increasing the gripping engagement of the gripping device.

A particular object, of the invention is to provide an improved actuating and locking mechanism for a movable gripping element which is adapted to engage a pipe to hold the same against upward movement; said mechanism being so connected with the gripping element that said element may undergo a limited inward movement with relation to the mechanism when the latter is in alocked position, holding the element in gripping engagement with the pipe, whereby any tendency of the pipe to move upwardly with relation to the element will eifect a tighter engagement of the element therewith.

A construction designedto carry out the invention will be hereinafter described, together with other features of the invention.

The invention-will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, in which an example of the inventionis shown, and wherein:

Figure 1 is a side elevation of a stationary snubber equipped with an auxiliary operating and locking means, constructed in accordance with the invention and applied toa well snubber,

Figure 2' is a plan view thereof,

Figure 3 is an end elevation of the same,

Figure 4. is a' partial longitudinal, sectional View taken on the line 4-l of Figure 2, c

.taken on the line 66 of Figure 2, and showing the latch in an engaged position,

Figure 7 is a similar view with the latch retracted,

Figure 8 is a horizontal, cross-sectional view taken on the line 88 of Figure 6,

Figure 9 is an isometric view of the auxiliary operating member or handle,

Figure 10 is an isometric view of the wrist pin,

Figure ll is an isometric view of the well snubber handle,

Figure 12 is a partial side elevation of a modified form of the invention, and

Figure 13 is a partial longitudinal, sectional view taken through the auxiliary operating lever of the modified form.

The invention is hereinafter described as applied to a well snubber of the usual construction, such as is shown in my Letters Patent Re. 19,498, but it is specifically pointed out that it may be employed to operate any gripping device wherein the gripping elements are actuated by an extended handle.

In the drawings, the numeral Ill designates the usual side plates of a stationary well snubber, which are spaced from each other by spacer bolts H. The plates are spaced sufficiently far apart to permit the elongate pipe, tubing or other element, A to extend therebetween. Gripping dogs iii are mounted between the plates at the central portion thereof and the inner arcuate faces of said dogs receive arcuate, gripping inserts l3, which inserts are formed with gripping teeth It. The arcuate inserts coact with each other to engage the pipe A, as is clearly shown in Figures 2 and 5.

Each dog is formed with a vertical rib I5 on its outer end and this rib is disposed between ears, or lugs, [6, which are provided on the inner end of an operating lever or handle H. A transverse pin l8 extends through the ears and also through a slot IS in the rib, whereby the inner end of the lever, or handle, is pivotally connected to the dog. It is noted that the slot I9 is inclined inwardly at its upper end, which permits the dogs to undergo a limited inward and upward movement with relation to the handles, as will be explained.

Each handle I! is keyed, or otherwise secured, on a transverse shaft 2!), which has its ends journaled in the side plates Ill. The outer ends of each shaft project through the side plates and one of said ends receives a nut 29, while the opposite end is fastened to one end of a link 2! (Figures 1 and 2). When the handles are swung, the shafts 2B are rotated to swing the links. The inner ends of the links are connected to each other by a pin 22 which extends outwardly from one link and engages within a slot 23 in the other link, and said links form a connection between the levers or handles 1! to assure said handles swinging simultaneously, with a resultant simultaneous movement of the gripping dogs l2 pivoted thereto. With such arrangement, it is only necessary to swing one handle and the other handle will be swung therewith due to the link connection therebetween.

The outer ends of the handles l'i project from between the side plates l0 and when said handles are in the position shown in Figure 5, with said outer ends raised, the dogs l2 are retracted i2 toward each other, whereby the teeth l4 engage the pipe and so long as said handles are lowered (Figure 4) the pipe is gripped or engaged bythe dogs.

The above construction, except for the slot l9, which could be omitted, is that of one type of the usual well snubbers now in general use, and forms no part of the present invention, having been described merely for the sake of clarity. The snubber may be supported in any suitable manner but is shown as resting on a supporting plate 24 which is attached to the upper end of the well casing. The side plates Iii of the snubber are tied down or attached to the supporting plates by tie-down bolts 25 and the pipe A pass ing through the snubber between the gripping dogs i2 extends downwardly into the well casing.

As has been pointed out, the relative short length of the handle I! provides a relatively small leverage, which makes it difficult to exert suiiicient force on the dogs to move them into a tight gripping engagement with the pipe or to cause them to bite into the surface of said pipe. This is particularly true if the teeth of the dogs are worn or the surface of the pipe is extremely hard. Also, with the usual handle, after the dogs have been moved to gripping position, they must be manually held in such positic-n by the operator holding the handle I! down by exerting a force thereagainst.

To amplify or increase the force exerted and to increase the leverage of the handle facilitate the swinging of said handle ll, whereby the gripping dogs I2 are moved into or out of engagement with the pipe A, an auxiliary lever or actuator 30 is provided. This lever includes a body portion or block 3! which has a general square shape in cross-section (Figure' 9) and an extension bar 32 is preferably made integral with the body, extending outwardly from one end thereof. The bar is of a greater height than the body, whereby its upper longitudinal edge is in a plane above the top of the body and a portion of said bar overlies the block. The upper portion of the bar is formed with an elongate, longitudinal slot 33.

The body or block 3| is disposed between a pair of extension plates 33, recessed or mortised so as to fit against the inner faces and ends of the side plates NJ, as is best shown in Figs. 2 and 3, and are secured to the inner faces of said side plates. These extension plates are bolted to said side plates by the spacer bolts II, and are thus rigidly held in place in parallel relation to each other, at the lower portion of the snubber. The extension plates form a rigid yoke for receiving the actuator or lever 30. The lever is pivoted between the projecting ends of the plates on a transverse bolt which passes through the outer portions of the plates and also through an opening 3'6 formed in the block 3| of the lever. The opening is located near the outer end of the block or body 39, whereby thegreater portion of said block is disposed between the plates 34 inside of the pivot bolt 35, as is best shown in Fig. 4. The outer end of the bar 32 of the lever projects outwardly from between the plates 34 and a suitable rod or handle 3'], which may be readily grasped by the operator, has one end fastened thereto. The rod 31 may be of any desired length and, manifestly, when the operator swings the rod, the lever 30, to

H, to

The groove is located near the outer end of the handle and is adapted to receive a wrist pin 39 which may rotate therein. The wrist pin is formed with a pair of transverse openings 40 (Figure 10) which are spaced from each other. The outer end of the handle I! has vertical slots 42 (Figure 11) whichslots are located in alinement with the openings in the pin 39.

A U-bolt or yoke 43 is confined within the longitudinal slot 33 of the auxiliary actuator or lever and has its arms 43' extending upwardly within the vertical slots 42 in the handle I! (Figs. 3, 4 and 5). The threaded extremities-of the arms of said U-bolt pass through the openings in the wrist pin and receive lock nuts 44, whereby the U-bolt is fastened to the wrist pin 39 and auxiliary lever 30 so as to connect the same. By adjusting. the lock nuts 44, the distance between the pin 39 and lever 3|! may be varied, whereby an adjustment is provided to compensate for variation in pipe diameters, irregularity or Wear in the pipe surface, or teeth of the gripping dogs, etc.

In operation, assuming that the gripping dogs are in a retracted position as shown in Figure 5, the outer end of the handle I! is raised, as is the outer end of the lever or actuator 30 and rod 31. The operator merely grasps the rod and moves the same downwardly so as to swing the extension' 32 of the lever downwardly. This extension has the U-bolt 43 confined within its longitudinal slot 33 and, therefore, a downward pull is exerted on the U-bolt, whereby the outer end of the handle I! is pulled downwardly. Such downward movement of the handle I! causes said handle to swing, rotating the shaft 20, on which it is mounted, whereby the other handle I! is swung through the links 2| and both dogs l2 are moved into gripping engagement with the pipe A. As the swinging of the lever 30 continues, the U-bolt 43 rides along the slot 33, such movement being permitted by the wrist pin which rotates in its groove 38 during this time. The swinging of the lever 30 by means of the rod 31 is relatively easy and requires little eifort, due to the fact that the leverage, ordinarily obtained by, the handle I! alone, is multiplied and increased bythe provision of the pivotally mounted auxiliary lever 30. When the dogs are in a gripping position, as shown in Figure 4, the lever 30 and rod 3'! are substantially horizontal and may be manually held in such position. The dogs l2 may undergo a limited inward and upward movement with relation to the handles l1 due to the inclined slot I!) through which thepivot pin l8 extends. The inclination of. the slot I3 is such that if there is any tendency of the pipe A to move upwardly while the dogs are gripping the same, the engagement between the pipe and dogs causes the dogs to move upwardly, whereby the inclined slots move said dogs into a tighter engagement with the pipe.

After the dogs J2 are engaged with the pipe, the auxiliary lever 30 may, if. desired, be manually held inthe position shown in Figured, whereby the dogs are maintained in gripping position. However, to obviate the necessity of manually holding said lever 33 and to automatically latch the same in this position, a sleeve (Figures 6, 7 and 8) has one end threaded into an opening 46 formed. in one of the extension plates 34 be tween the pivot bolt 35 and the spacerbolt I I. A

latching plunger 41 is slidable within the sleeve and has its inner end adapted to project beyond the inner side of the plate into the path of the swinging lever 3|). A coiled spring 43 is confined between the other end of the plunger and a plug 49 which is threadedinto and closes the outer end of. the sleeve 45 and this spring constantly urges the plunger inwardly toward the lever 30 to the position shown in Figure 6.

For limiting the'movement of the plunger within the sleeve and also for retracting said plunger, as willbe explained, the top of said plunger is formed with a recess 50 within which a cam 5| is located. The cam is eccentrically mounted on a shaft 52 which extends upwardly through an opening 53 in-the top of the sleeve. An operating arm 54 is fastened to the upper end of the shaft and by rotating said arm, the cam 5| is revolved. I

When the cam is in the position shown in Figure 8, the spring 49 acting against the plunger moves the end of. the plunger inwardly toward the lever 30 so that the end of said plunger projects beyond the inner side of the plate 34. With the plunger in this position and with the auxiliary lever or actuator 3|) in the position shown in Figure 5, the top of the block 3| of said lever is below theplunger. In thisposition, the gripping dogsare in a released position.

As the lever 38 is swung to move the dogs into gripping engagement with the pipe l2, as has been explained/the top of the block 3il'strikes the projecting end of the plunger 4'! and depresses the same under tension of the spring 48. This projecting end of the plunger may be rounded, as shown at 4'| to facilitate its engagement and depression by the block. As the plunger is depressed, the block 3| moves upwardly to aline a recess 55, formed in the side of said block, with said plunger, whereupon the springflfi immediately moves the end of the plunger intosaid recess. The recess 55 is positioned so as to, receive the'plunger 4'! after the dogs |2 have moved into gripping engagement with the pipe, whereby the plunger, locks said lever against a return movement and thus the dogs are maintained in their engaged position. The bottom of the recess 55 is open (Figure 9) so that if it is desired to further tighten the dogs after the plunger 41 has entered the recess, this can be done. plunger locks the lever against movement in one direction only, such movement being swinging of the inner end of theblock 3| in a downward direction, which releases the dogs. In thismanner,

the gripping dogs it are maintained in gripping position so long as the plunger-l engageswithin. the recess 55.

When the .dogs are to be released from the pipe A, the operating arm 54 on the cam shaft .52 is rotated'to revolve the cam 5|. Rotation of thethe rod 3| and extension 32 are swung upwardly,

which moves the inner end ofthe block 3| downwardly. Upward swinging of the extension 32 causes the same to engage the lower end of a depending lug or abutment 56, which is secured to the outer end of, the snubber handle IT by bolts Thus, the

:tion of the dogs.

51, and thereby move the outer end of the handle upwardly, which results in a retraction of the dogs l2 from their gripping engagement with the pipe. t is noted that, if desired, the lug 563 may be omitted, in which case the extension 32 would engage the underside of the handle H to move it upwardly. The use of the lug is preferable because the extension 32 does not have to travel as great a distance in order to release the dogs l2.

In Figure 12, a modified form of the invention is shown, wherein inclined extension plates 35' are substituted for the plates 34. An auxiliary lever or actuator 30' is pivotally mounted between the plates 34 on a bolt 35'. The lever 39 includes a block 3| having a rod 37' extending outwardly therefrom and this lever is adapted to be swung in the same manner as the lever 3i} in the first form. The block 39 has an upstanding book 60 which is arranged to be engaged with the U-bolt 43, whereby said block is connected with the handle ll of the snubber. The operation of this form of the invention is substantially the same as the first form, the auxiliary lever or actuator 38 being utilized to actuate the handle l1 and move the gripping dogs. If desired. the latch, including the sleeve and plunger 41, may be mounted in one of the extension plates 34 and said plunger coacts with a recess (not shown) in the lever 38' to lock the lever against movement to a releasing position.

From the foregoing, it will be seen that the provision of the auxiliary lever or actuator amplifies the leverage and greatly facilitates opera- One man may quickly and easily move said dogs into gripping engagement and after being so moved, the dogs are held in such position by the latch plunger 41 which prevents return of the auxiliary lever to its original position. Thus, the dogs are automatically latched in gripping position and cannot be retracted until the plunger is manually disengaged from the recess in the auxiliary lever.

It is pointed out that although the invention has been shown and described as applied to a 1 out departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

1. The combination with a movable gripping device having a face for gripping an elongate member, of a support, a handle fulcrumed in.-

termediate its end on said support and also pivoted to said gripping device, a lever pivoted on the support and having its pivot spaced further from the gripping device than the pivot of the handle, a U-bolt having its upper end mounted on the outer end of the handle and therefrom, the lever having a longitudinal slot therein through which the LI-holt extends, whereby said lever and handle are connected to- ...gether and the lever may be utilized to swing the handle.

member, of a support, a handle iulcrumed intermediate its end on said support and also connected to said gripping device, a lever pivoted on the support and having its pivot spaced further from the gripping device than the pivot of the handle, a U-bolt having its upper end pivotally mounted on the outer end of the handle and depending therefrom, and a hook on the lever for engaging the U-bolt to connect the handle and lever together, whereby the lever may be utilized to swing the handle.

3. In a well pipe snubbing device, the comhination of a movable gripping device for engaging said pipe and a handle fulcrumed intermediate its ends for operating said gripping device which is pivoted to one end of said handle, of an actuator including a pivoted lever, a pivotal element for connecting said lever adjacent its pivot point to the handle on the opposite side of its fulcrum from its point of connection to the gripping device so as to amplify the leverage of the handle when the lever and handle are swung, and means for locking the lever when the gripping device is at one end of its movement.

4. In a well pipe snubbing device, the combination with a support operable with a pipe including a gripping device for engaging such pipe and a handle pivoted on the support and having the gripping device pivoted to its inner end, of a lever pivoted on the support below the handle and having its pivot spaced further from the gripping device than the pivot of the handle, a U-bolt having its upper end mounted on the outer end of the handle, and means for pivotally connecting the U-bolt with the lever adjacent the pivot thereof.

5. A well pipe snubbing device as set forth in claim 4 and a latch carried by the support and engaging the lever.

6. A well pipe snubbing device as set forth in claim 4 and a projection on the handle disposed. to be engaged by the lever upon its upward swing to swing said handle and retract the gripping device.

7. A well pipe snubbing device as set forth in claim 4 wherein the support is provided with extension plates and the lever is pivotally on said plates.

8. A well pipe snubbing device as set forth in claim {1 and a member attached to the lever having a slot therein extending longitudinally of the lever for receiving the lower end of the U-bolt for pivoting the said bolt to the lever.

9. A well pipe snubbing device as set forth in claim 4 wherein the U-bolt is pivoted to the lever by a hook.

10. In a well snubbing device, the combination of a support open for receiving an upright well tubing, opposed gripping elements disposed in the support for engaging a pipe and holding it against longitudinal movement, a handle fill crumed intermediate its ends on said support and connected at its iner end to one of the gripping elements, a lever pivoted on the support adjacent the handle, means connecting the lever and the handle for swinging the handle and moving the gripping element connected thereto into gripping position, and an abutment on the handle disposed to be engaged by the lever when the latter is swung in the opposite direction to swing the handle to release the gripping element.

HERBERT C. OTIS.

Gib

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