US2747617A

US2747617A - Thread protectors

Info

Publication number: US2747617A
Application number: US357864A
Authority: US
Inventors: Walden John
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-05-27
Filing date: 1953-05-27
Publication date: 1956-05-29
Anticipated expiration: 1973-05-29

Description

May 29, 1956 .1. WALDEN THREAD PROTECTORS Filed May 2'7, 1955 I e? f.

. INVENTOR (10km Valdem BY WW O 1a,,.,,,,,,,,unnnuj ATTORNEYS United States Patent THREAD PROTECTORS John Walden,.SanAngelo, Tex.

- Application May 27,1953, serialNoi 357,864

:7 Claims. 01. 138-96) This invention relates to caps, or protectors, -which may befitted-oven the end of a pipe having external threads to protect the threads against damage while the pipe is being handled. V

In well working, particularly in the oil field, sections of pipe have tobe raised to -avertical position for lowering into the well. This is usually accomplished by fastening a cable to one end. In hoisting the'pipe-the lower end is dragged over the ground and, unless protected, the threads are damaged. It has been the custom to thread a cap over the threaded lower end, but the cap is difiicult to remove, and if it catches upon a projection while thepipe is being lifted, the cable is apt to break and the pipe fall, jeopardizing the lives of workmen. f The principal object of the. present-invention is to provide a thread protector for pipe which can be placed upon, and removed from, pipe quickly and with minimum .eifort.

A further :object is to provide a protector whichwill be stripped from the pipe before damage can result in the event the protector-should catch upon the derrick platform or other obstacle.

A more specific object is to provide a device of this nature which will engage the pipe threads by friction only, with means for releasing its frictional hold on the pipe for removal from the pipe.

Another object is the provision of a protector which may be manufactured at low cost, and yet will be reuseable over long periods of time.

Other objects of the invention will become apparent from the following description of one practical embodiment thereof, when taken in conjunction with the drawings which accompany, and form part of, this specification.

In the drawings:

Figure 1 is a perspective view of one end of a length of pipe with a protector embodying the principles of the present invention in place covering the threaded portion thereof;

Figure 2 is an end view of the protector in closed, or thread-gripping, position;

Figure 3 is a view similar to Figure 2 showing the protector in open position for placing upon, or removing from, a pipe end; and,

Figure 4 is a longitudinal section through the protector in place upon a pipe end, and is taken upon the line 44 of Figure 2.

In general, the invention comprises a longitudinally split, spring steel sleeve with means for spreading the sleeve to enlarge its diameter to permit slipping it over a pipe end, which, when released, will frictionally grip the pipe to firmly hold it upon the pipe end.

Referring to the drawings in detail, there is shown a thread protector 1 which may be placed upon the end of a section of pipe 2 having external screw threads 3. The protector consists of a longitudinally split sleeve 4 of spring steel. The cylindrical curvature of the spring steel sleeve has been pre-set so that in its normal unice sprung position the ends 5 and Get the sleeve :will overlap one another an appreciable distance, as shown in Figure 2. The bottomedge of the sleeve is rolled over-to form a head 7 to add rigidity to the sleeve and to -prevent injury to workmen in handling the device.' Because of the overlapping of'the end sections of thesleeve, the bead is discontinued in the: overlapping area. Because of this rolled head, the upper portion of the sleeve will expand a greater distance when the sleeve is spread, so that the upper, orleading, end of the sleeve will -flare slightly outwardly to facilitate 'placing the sleeve over the end of apipe.

The sleeve nearits lower end is bridged by two normally abutting spreader plates 8 and 9I These plates are of-less' width than 'the diameter of the sleeve and their outer edges are arcuate to conformto the wall of the cylindrical sleeve. The plates aresecured to the walls of the sleeve by'Welding-along these arcuate edges. Plates lie in the same-horizontal plane, and their confronting edges are in substantial abutment-when the cylinder is in its normal, unsprung condition. 'The confronting edges ofthe plateshave companion arcuate'recesses l0 and 11 which, when the' plates are in abutting relation, form a pear-shaped opening.

The cylinder is caused to spread and to be released by means of a;cam. 12 which is of the same shape as the openingiormedzbyxthe recesses 10 and 11- and of the same: thickness. as' the. spreader plates 8 and 9. Thus the 'camzwilluexactly fit the opening when the'cylinder isin itstunsprungpposition. Cam.12 is provided with a= square aperturelS- inorder to receive an operating handle-14.v Handle 14 has a square ishank 15 .which :fits within the opening 13 in the cam to rotate the cam when the handle is'moved. 'The handle also has a stud -16.projecting:,beyond the square shank which is cylindrical and-.screwrthreaded. A circular flange 17 of larger diameter than the width of the opening formed by the recesses in the spreader plates is provided on the handle to bear against one side of the spreader plates to prevent the handle from moving through the opening. A Washer 18 is slipped on the stud 16 on the opposite side of the spreader plates, and a nut 19 is threaded onto the stud to lock the assembly in position. Washer 13 may be similar in shape to the opening formed by the recesses in the plate, but of larger dimensions to prevent the handle pulling through the opening. If desired, stud 16 may be apertured and a cotter pin 20 passed through the aperture to lock nut 19 in position on the stud.

When handle 14 is rotated in either direction, cam 12 will bear upon the arcuate surfaces of the

opposing recesses

10 and 11 in the spreader plates and force the plates apart. This motion will be transmitted by the plates to opposite sides of the cylindrical sleeve and cause the sleeve to spread to enlarge its diameter. The overlapping of the

ends

5 and 6 of the sleeve is willcient so that these ends will remain in overlapping relation when the sleeve is spread to its maximum extent. When in this position the sleeve will slip freely over the end of the pipe which is to be protected, and when the handle is moved back to its position of rest, the inherent resiliency of the spring steel sleeve will cause the sleeve to contract about the end of the pipe to frictionally engage the pipe end. If desired, the interior surface of the sleeve between the spreader plates and the top edge thereof may be lined with rubber or other resilient gripping material to facilitate obtaining a tight gripping upon the pipe end. The threads on the end of the pipe will compress the resilient lining and hold against accidental longitudinal movement of the sleeve. Even though the grip of the protector on the pipe is quite firm and serves to hold the protector against accidental displacement, the sleeve will be readily stripped from the end of the pipe if it should catch on a projection while the pipe is being moved It will be obvious that when the portector has served its purpose, movement of the handle will release its grip upon the pipe end and it may be removed for reuse at a later time.

While in the above, one practical embodiment of the invention has been disclosed, it will be understood that the specific details of construction described and illustrated are merely by way of example, and that various changes may be made within the scope 'of the appended claims.

What is claimed is: p

l. A protector for externallythreaded pipe ends comprising, a spring steel longitudinally split sleeve, spreader plates attached along one edge to the side Wall of said sleeve near one end thereof and on opposite sides of the split in said sleeve, said plates lying in a common plane and having their confronting edges in substantial abutment with one another when the sleeve is-in its normal unsprung position, said plates having companion and opposite recesses in the confronting edges thereof to form an opening, a cam seated in said opening, and means to rotate said cam to spread said sleeve.

2. In a protector for externally threaded pipe ends as claimed in claim 1, a lining of resilient material on the inside of said sleeve to contact the threads of a pipe when the protector is upon the pipe.

3. A protector for externally threaded pipe ends comprising, a spring steel longitudinally split sleeve, spreader plates attached along one edge to the side wall of said sleeve near one end thereof and on opposite sides of the split in said sleeve, said plates lying in a common plane and having their confronting edges'in substantial abutment with one another when the sleeve is in its normal unsprung position, said plates having companion and opposite recesses in the confronting edges thereof to form an opening, a cam seated in said opening, and a handle connected to said cam to rotate said cam to force the spreader plates apart and spread said sleeve.

4. In a protector for externally threaded pipe ends as claimed in claim 3, said opening being pear-shaped, and said cam'being of such size and shape as to exactly fit said opening.

5. A protector for externally threaded pipe ends comprising, a spring steel longitudinally split sleeve, spreader plates attached along one edge to the internal side wall of said sleeve near one end thereof and on opposite sides of the split in the sleeve, said spreader plates lying in the same plane and having confronting edges in substantial abutment with one another when the sleeve is in its normal unsprung position, said plates havingcompanion recesses in the confronting edges thereof to form an opening, a cam of the same shape and size as said opening seated therein, said cam having a square hole therein, a handle having a portion to bear against one side of said spreader plates and a squareshank seated in said hole in said cam, a stud projecting from said shank, a washer on the shank, and means to lock the handle and cam in assembled relation.

6. In a protector for externally threaded pipe ends as claimed in claim 5, said opening being pear-shaped.

7. In a protector for externally threaded pipe ends as claimed in claim 5, a lining of resilient material on the inside of said sleeve to contact the threads of a' pipe when the protector is upon a pipe.

References Cited in the file of this patent UNITED STATES PATENTS Holland Aug. 15, 1935