US3637011A

US3637011A - Clamp for well pipe

Info

Publication number: US3637011A
Application number: US85360A
Authority: US
Inventors: Eugene F Wheeler
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-10-30
Filing date: 1970-10-30
Publication date: 1972-01-25
Anticipated expiration: 1989-01-25

Abstract

A clamp for holding a string of pipe suspended in a well. The clamp is mounted upon a flat plate which is secured to the well casing to prevent it from rotating. The plate has a throat at one side to receive a pipe suspended in the well and vertically splined jaws form a V-notched abutment at the crotch of the throat. A clamp arm having a horizontally splined head is pivotally mounted upon the plate to be pulled against a pipe in the throat to engage the pipe between the jaws and the head. A cammed pull rod connecting with the arm engages a cam seat on the plate to lock the jaws and head onto the pipe and prevent it from slipping and rotating in the clamp.

Description

[ 1 Jan. 25, 1972 [54] CLAMP FOR WELL PIPE [72] Inventor: Eugene F. Wheeler, Franktown, Colo.

[22] Filed: Oct. 30, 1970 [21] Appl. No.: 85,360

Wilson ..24/249 DP Unglesby ..24/249 PC Primary Examiner-James A. Leppink Anorney-Van Valkenburgh and Lowe [57] ABSTRACT A clamp for holding a string of pipe suspended in a well. The clamp is mounted upon a flat plate which is secured to the well casing to prevent it from rotating. The plate has a throat at one side to receive a pipe suspended in the well and vertically splined jaws form a V-notched abutment at the crotch of the throat. A clamp arm having a horizontally splined head is pivotally mounted upon the plate to be pulled against a pipe in the throat to engage the pipe between the jaws and the head. A cammed pull rod connecting with the arm engages a cam seat on the plate to lock the jaws and head onto the pipe and prevent it from slipping and rotating in the clamp.

6 Claims, 5 Drawing Figures PATENTED JANZSIHYZ 306N131 l SHEET 1 0F 2 --w1 INVENTOR.

BY Eugene H Wheeler Fig. 2 z We Ai 7 ATTORNEYS PATENTEU JA-251972 3,637,011

sum 2UP 25 2s 29 48L 2e 7 I Fig. 5

I v INVENTOR.

Eugene E Wheeler ATTORNEYS CLAMP FOR WELL PIPE The present invention relates to clamps for holding a string of pipe suspended in a well while the pipe is being installed in, or removed from, the well. As such, the invention will be called a "clamp for well pipe."

Whenever pipe is being installed in or removed from a well, it is necessary to hold the depending string of pipe at the head of the well to protect it against falling into the well and also to hold it against turning when couplings and pipe sections above the well head are being screwed onto or off from the pipe string. Various types of apparatus are provided for this purpose. In large, deep wells where the pipe string is heavy, regular drilling rigs having rotating tables, slips and tongs are necessary to hold the string of pipe. In small, comparatively shallow wells, such as water wells, the string of pipe is held by hand tools such as Stillson wrenches. This is usually satisfactory because the weight of the string is not excessive. However, sooner or later, the wrench will slip causing an expensive fishing job if not a more serious accident.

Several types of clamps have been developed for holding a string of pipe in a small well, and the patent to B. G. Bjalme, US. Pat. No. 2,854,216, issued Sept. 30, 1958, is exemplary of this development. While such devices are an improvement over Stillson wrenches, they are not completely satisfactory because they are awkward to use.

There is a real and definite need for an improved and simplified clamp for holding well pipe, and the present invention was conceived and developed with such need in view. The invention comprises, in essence, a clamp for well pipe which is formed upon a baseplate, which, in turn, is mounted and secured to the head or top of the well casing. The clamp is a quick-acting arrangement of gripping arms for holding and releasing the end of a string of pipe as the string is being made up and lowered into the well, as will be hereinafter described.

An object of the present invention is to provide a novel and improved clamp for holding well pipe which will rest upon and be secured to the head of the well casing to hold the top of a string of pipe in the well in a safe, secure manner while pipe sections and couplings above the clamp are being added onto or removed from the string.

Another object of the invention is to provide a novel and improved clamp for holding a string of pipe in a well which may be mounted upon the head of the well casing and secured thereto against turning, so that the operator may screw on, or olf, other pipe sections above the well head, and tightly make up pipe sections fitted onto the string or break connections rusted together when pipes are to be disconnected, all without the necessity of holding the clamp.

Another object of the invention is to provide a novel and improved clamp for well pipe which, once mounted upon a casing head, can quickly and solidly grip the top of a string of pipe suspended in the well and also quickly release the string when necessary.

Other objects of the invention are to provide a novel and improved clamp for well pipe which is a simple, compact, economical, rugged and reliable structure.

With the foregoing and other objects in view, all of which more fully hereinafter appear, my invention comprises certain constructions, combinations and arrangements of parts and elements as hereinafter described, defined in the appended claims and illustrated, in preferred embodiment in the accompanying drawing in which:

FIG. 1 is an isometric view of the improved well clamp mounted upon the head of a well casing and holding the top of a string of pipe suspended in the well.

FIG. 2 is a plan view of the arrangement shown at FIG. 1 with broken lines indicating parts hidden from view, and an alternate position of a locking member.

FIG. 3 is a transverse sectional view as taken from the indicated line 3-3 at FIG. 2, but on an enlarged scale, without the clamp holding pipe as shown at FIGS. 1 and 2 and with a connective pin normally hidden from view being shown in broken lines.

FIG. 4 is an end view partially in section, as taken from the indicated offset line 44 at FIG. 2, but on an enlarged scale.

FIG. 5 is an isometric, exploded view of the components forming the clamp as taken from the side opposite the showing at FIG. 1, as from the indicated arrow 5 at FIG. 1.

Referring more particularly to the drawing, the improved clamp C is formed upon a rectangular baseplate 20 which is adapted to set upon and to be secured to the end, or head of a well casing W. The well casing is ordinarily a pipe varying from 48 inches in diameter and the baseplate 20 is of a length sufficient to overlie the larger casing as well as the smaller, and of a width to partially overlie either the larger or smaller casing. This baseplate is formed with a throat 21 which extends from the center of one side edge of the plate approximately halfway into the baseplate and which is of sufficient width as to receive a well pipe P varying from l-3 inchesjn diameter. A clamping means is located at this throat as will be described.

A means is provided to secure this baseplate 20 upon the head of the casing which includes three spaced lugs 22 depending from the underside of the baseplate 20, one being at the side edge opposite the throat 21 and the other two being at the ends of the baseplate adjacent to the throat edge as best indicated by the dotted lines at FIG. 2. A tapped hole in each lug carries a bolt 23, and this triad of bolts are extended to the walls of the well casing W to securely engage the casing and place the throat 21 approximately over the axial center of the casing as illustrated. These lugs 22 and bolts 23 are preferably fairly heavy members to resist twisting; forces upon the casing when a pipe or coupling is being screwed onto or off from the pipe string P held in the clamp C.

The pipe-gripping members at the throat 21 include a comparatively thick body 25 having gripping jaws 26 in the form of a V-notch. This body is securely affixed to the top surface of the baseplate 20 as by a bolt 27, FIG. 3, with the V-notch being at the crotch of the throat 21. The body 25 is also positioned against a saddle at the center of an upstanding abutment bar 28 welded to the surface of the baseplate 20 as at 28. The jaws 26 are ridged with gripping splines 29 extending across the jaws to be vertical when the clamp is set upon the well casing W. Thus, whenever a pipe P is wedged into the notch formed by the jaws 26, the grip of the splines will prevent the pipe P from rotating. The pipe-gripping members also include a clamp head 30 which is carried upon a clamp arm 31. This arm 31, pivoted upon the body 20, will push the head 30 against the pipe P. Transverse splines 32 are formed upon the face of this head 30 to be horizontal when the clamp is set upon the well casing W. Thus, whenever a pipe P is pushed into the notch, formed by jaws 26, by the head 30, the splines 32 will grip the pipe to prevent it from sliding downwardly in the clamp to supplement the grip of the jaw splines 29 which keep the pipe from turning. The clamp head 30 is secured to the arm 31 by machine screws as at 33 shown in FIG. 3.

The abutment bar 28, formed as a spreading V, has one end curved on a reverse curve to form a pivot seat 34 to hold one end of the arm 31. The other end of the abutment bar 28 is also curved, on a reverse curve, and slotted to form a seat 35 for a lock cam, as hereinafter described.

The pivot end of the clamp arm 31 is formed as a clevis 36 which is adapted to straddle the abutment bar 28 with the eyes 37 of the clevis receiving a pivot pin 38 which lies against the pivot seat 34 of the abutment bar 28. To permit the clevis to straddle the abutment bar with one head of the clevis lying against the surface of the body 25, the abutment bar is slotted, as at 39, at the pivot seat portion 34, as: best illustrated at FIG. 5. The other head of the clevis overlies the top edge of the abutment bar 28, as best illustrated at FIG. 1. This pivot pin is of a length in excess of that required to straddle the eyes of the clevis and the lower portion will extend into a socket hole 40 in the baseplate 20 as shown in broken lines at FIGS. 3 and 5. This pin may be pressed, screwed or welded into the socket hole to make a permanent connection if desired.

The opposite end of the clamp arm 31 is formed as a handle 41 to facilitate an operator gripping the same and pulling the clamp head 30 against a pipe P and to hold the arm in this position until it can be locked by a cam 42. The cam 42, which engages the cam seat 35 as will be described, includes a threaded pull rod 43 which extends through a hole 44 in the clamp arm adjacent to the handle. The pull rod is held against the clamp arm by a nut 45, which is preferably a jamnut to prevent it from turning once the apparatus is adjusted for a given size pipe. The fit of the pull rod 43 in this hole 44 is comparatively loose to facilitate moving the cam 42 upon and away from its seat as will be described.

The cam 42 also includes a pair of aligned, disc-shaped lobes 46 which are spaced apart to place the pull rod 43 between them and which are secured together by a head 47 at one edge of the lobes. A handle 48 is connected to the head to rotate the lobes as will be described. The end of the pull rod 43, which lies between the lobes 46, is formed with an eye 49 as shown in section at FIG. 4 and in broken lines at FIG. 2, and a pivot pin 50 extends through the lobes at an eccentric position and through the eye to connect the pull rod to the lobes. The eccentric position of the pin 50 through the lobes 46 is such that the handle 48 extends away from the clamp C when the cam is loose and the lobes are not engaging the seat 35, as shown in broken lines at FIG. 2, and is such that the handle 48 rests against the abutment bar 28 when the cam is locked as shown in solid lines at FIGS. 1 and 2.

The cam seat 35, at the end of the abutment bar, is formed with a central slot 51 through which the pull rod 45 extends whenever the lobes 46 engage the seat 35. The seat 35 is curved or dished slightly to prevent the cam lobes 46 from slipping out of position whenever the cam is tightened and locked to pull the arm 31 against a pipe. However, the seat is sufficiently flat as to permit the cam lobes to be removed from the seat whenever they are rotated to a loose, unlocked position. When the cam is removed from the seat it is possible to swing the arm 31 and the cam 42 connected thereto completely out of the way, as when the pipe is to be pulled out of the well.

The use of this clamp is simple. When a string of pipe is to be lowered into or pulled out of a well, and sections of pipe must be added or removed from the string, the pipe clamp is set upon the top of the well casing W which ordinarily extends a few inches to a foot or more above the ground surface. The clamp is then tightly secured to the top of the well casing by bolts 23 with the jaws 26 being approximately at the center of the casing. Thus, the clamp will not rotate upon the casing. The pull rod nut 45 is then adjusted so the clamp jaws 26 and head 30 will grip the pipe in the well. Thereafter, when the pipe string is to be gripped, the arm 31 is pulled against the pipe, the cam 42 is shifted to its seat 35 and the lobes are rotated to the locked position. The arm then holds the pipe tightly, with the splines 32 of the head gripping the pipe to prevent it from dropping into the well and the splines 29 of the notch gripping the pipe to prevent it from being turned. The operator is then free to apply wrenches to turn on or off couplings and other pipe lengths above the pipe section held by the clamp. Thereafter, the string is connected to the well hoist to be lowered or raised, so the clamp may grip another section of the string to continue the operation.

I have now described my invention in considerable detail. However, it is obvious that others skilled in the art can build and devise alternate and equivalent constructions which are nevertheless within the spirit and scope of my invention. Hence, I desire that my protection be limited, not by the constructions illustrated and described, but only by the proper scope of the appended claims.

Iclaim:

l. A clamp for holding a string of pipe in a well which has casing at the top of the well, said clamp comprising:

a. a flat baseplate adapted to rest upon and to overlie the top of the well casing and having a throat at one side to receive a pipe extended into the well;

b. a splined jaw means forming a V-shaped abutment at the crotch of the baseplate throat to engage a pipe received therein; c. a clamp arm pivotally mounted upon the baseplate to move against a pipe in the throat of the baseplate and to push the same against the jaw means;

d. a splined head carried upon the clamp arm opposite the jaw means to engage a pipe being pushed against the jaw means by the arm, the splines in the head being oriented transversely to the splines in the jaw means to hold the pipe against slipping and rotation;

e. a cam seat on the baseplate; and

f. a cam lock means connecting with the arm and with the cam seat to hold the clamp arm tightly against a pipe in the throat of the baseplate.

2. In the clamp defined in claim 1, including a securing means adapted to secure the baseplate upon the casing to prevent it from rotating with respect to the casing whenever couplings or other pipe links are being screwed onto or off from a pipe held by the clamp.

3. In the clamp defined in claim 2, wherein said securing means includes a plurality of locks about the baseplate with bolts therein extending inwardly and adapted to be turned against the well casing.

4. In the clamp defined in claim 1, including an abutment bar upstanding from and secured to the plate to extend thereacross with the central portion forming a saddle to hold the jaw means, with one end forming a pivot seat whereto the clamp arm is pivotally mounted with the end opposite therefrom forming the aforesaid cam seat.

5. In the clamp defined in claim 4, wherein the cam lock means includes:

a disc adapted to engage the cam seat at the side opposite the clamp arm;

a pull rod extending from the disc to the clamp arm with the connection of the pull rod to the disc being eccentric; and

a means for rotating the disc from a first position where the eccentric is toward the clamp arm with the connection between the clamp arm and the cam seat being loose, and to a second position where the eccentric is away from the clamp arm with the connection between the clamp arm and the cam seat being tight and the pull rod pulling the clamp arm against the pipe.

6. In the organization defined in claim 5, wherein said means comprises a handle connected to the disc at a position where it is rotated against the abutment bar when the pull rod is pulling the arm.

Claims

1. A clamp for holding a string of pipe in a well which has casing at the top of the well, said clamp comprising: a. a flat baseplate adapted to rest upon and to overlie the top of the well casing and having a throat at one side to receive a pipe extended into the well; b. a splined jaw means forming a V-shaped abutment at the crotch of the baseplate throat to engage a pipe received therein; c. a clamp arm pivotally mounted upon the baseplate to move against a pipe in the throat of the baseplate and to push the same against the jaw means; d. a splined head carried upon the clamp arm opposite the jaw means to engage a pipe being pushed against the jaw means by the arm, the splines in the head being oriented transversely to the splines in the jaw means to hold the pipe against slipping and rotation; e. a cam seat on the baseplate; and f. a cam lock means connecting with the arm and with the cam seat to hold the clamp arm tightly against a pipe in the throat of the baseplate.

5. In the clamp defined in claim 4, wherein the cam lock means includes: a disc adapted to engage the cam seat at the side opposite the clamp arm; a pull rod extending from the disc to the clamp arm with the connection of the pull rod to the disc being eccentric; and a means for rotating the disc from a first position where the eccentric is toward the clamp arm with the connection between the clamp arm and the cam seat being loose, and to a second position where the eccentric is awaY from the clamp arm with the connection between the clamp arm and the cam seat being tight and the pull rod pulling the clamp arm against the pipe.