US3789679A

US3789679A - Pumping unit safety guard

Info

Publication number: US3789679A
Application number: US00343929A
Authority: US
Inventors: V Westbrook
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-04-12
Filing date: 1973-04-12
Publication date: 1974-02-05
Anticipated expiration: 1991-02-05

Abstract

A brace bar is placed between pitmans of a pump jack to maintain the crossbeam in proper position in the event one of the wrist pins holding one of the pitmans to the crank arm comes loose.

Description

[ Feb.5,1974

[ PUMPING UNIT SAFETY GUARD Virgil H. Westbrook, PO. Box 2264, Hobbs, N. Mex. 88240 Apr. 12, 1973 [76] Inventor:

10/1966 Chastain.........:::::::.......::::i..173/83 [22] Filed:

Primary Examiner-Benjamin W. Wyche Assistant ExaminerWesley S. Ratliff, Jr. Attorney, Agent, or FirmWendell Coffee Appl. No.: 343,929

T C A R T m "H .6. 2 B 51 42 h 6 l 1 NF 4. 0 QML Um UH U5 [58] Field of Search........................ 74/41, 590-592,

A brace bar is placed between pitmans of a pump ack 74/591, 581,173/83 to maintain the crossbeam 1n proper position in the [56] References Cited event one of the wrist pins holding one of the pitmans UNITED STATES PATENTS to the crank arm comes loose.

1,895,!81 l/1933 Trout....................... 74/41 3 Claims, 2 Drawing Figures w/IWIlI/llllll'a 1 PATENTEDFEB 51974 sum 2 BF 2 PUMPING UNIT SAFETY GUARD BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to pump jacks and more particularly to preventing damage to pump jacks in case of mechanical failure of parts.

2. Description of the Prior Art Pump jacks are well known mechanical devices, and of the type used here, are commonly used to pump petroleum products from wells deep within the earth. Basically, they include a sampson post supporting a walking beam. One end of the walking beam has a horsehead from which is suspended a sucker rod which extends to the pump. The other end of the walking beam has a crossbeam by which are connected pitmans to crank arms of a rotating shaft.

It has been found desirable to provide the connection of the pitmans to the crossbeams so the pitmans may be swung outward, which is to say, they are laterally movable. 1

It will be understood that often times there is wear at the wrist pin wherein each pitman is connected to the crank arm. Therefore, if there is any adjustments to be made or if the wrist pin is to be removed, the pump may be stopped and the sucker rod blocked up, then the wrist pin disconnected and the pitman swung outwardly to disengage the pitman and wrist pin from the crank arm.

This arrangement of the pitman laterally movable to the crossbeam makes a pump jack extremely easy to maintain. However, it has the inherent danger that if a wrist pin breaks or becomes disconnected or the pitman becomes disconnected from a wrist pin, damage results. Analysis will show that damage results because if one pitman comes loose, the walking beam is connected solely to a pitman which is offset to one side. This twists the walking beam around which does damage to the saddle, whereby the walking beam is attached to the sampson post. Also, in severe cases when the walking beam is pulled to one side in such a manner that it may do damage to the stuffing box or to the polish rod of the sucker rod.

Other type pump jacks have cross braces or cross framing connecting the two pitmans together which eliminate the damage described above. However, in such cases, the cross bracing is permanently attached so when it is desired to change wrist pins or make adjustments, the pitmans cannot be swung outward, making maintenance more difficult.

The following patents were considered in preparing this application: Mahan, U. S. Pat. No. 1,752,647; Livingston, U.S. Pat. No. 1,979,803; Johnson, US. Pat. No. 2,958,273.

SUMMARY OF THE INVENTION NEW AND DIFFERENT FUNCTION I have solved the dillima posed above by providing a brace bar between the pitmans, said bar being readily detachable from each of the pitmans. With the bar in place, the pump jack has all of the advantages of a pump jack with crossframing. Therefore, the pump unit according to my invention has all of the safety features of having the two pitmans rigidly connected together with a permanent crossbracing. However, by having the brace bar readily detachable from each of the pitmans, my pump jack has also all of the advantages of easy maintenance. My pump jack has the advantages of either of the types of pump jacks commonly in use and none of the disadvantages.

OBJECT S OF THE INVENTION An object of this invention is to produce oil by pumping it from underground to the surface of the earth.

Other objects are to achieve the above with a device that is sturdy, compact, durable, lightweight, simple, safe, efficient, versatile, and reliable, yet inexpensive and easy to manufacture, install, operate, and maintain.

Further objects are to achieve the above with a method that is versatile, rapid, efficient, and inexpensive, and does not require skilled people to install, operate and maintain.

Further objects are to achieve the above with a method that is versatile, rapid, efficient, and inexpensive, and does not require skilled people to install, operate, and maintain.

The specific nature of the invention, as well as other objects, uses, and advantages thereof, will clearly appear from the following description and from the accompanying drawing, the different views of which are not necessarily to the same scale.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a pump jack with my invention attached thereto; the drawing somewhat foreshortened in all respects for clarity of illustration.

FIG. 2 is a sectional view.

DESCRIPTION OF THE PREFERRED EMBODIMENT:

Referring more particularly to the drawing, there may be seen represented a pump jack having sucker rod 10, the upper portion of which forms polish rod 12. The polish rod is connected by bridle to horsehead 16. The horsehead 16 is one end of the walking beam 18. The sucker rod extends through packing gland 20 on top of tube 22. The sucker rod 10 extends through the tube 22 to a pump located far beneath the surface of the earth on the bottom of the tube. Saddle 24 on top of sampson post 26 forms a pivot connection for the walking beam 18. The end of the walking beam opposite from the horsehead 16 has crossbeam 28 thereon. i Pitrnan 30 and pitman 32 are attached by pivot pins 34 to the ends of the crossbeam 28.

Main drive shaft 36 is journaled to the foundation. The main drive shaft is'driven by prime mover 38. The prime mover may be either an electric motor or internal combustion engine. Crank arms 40 and 42 are connected to the main drive shaft. Counterbalance weights 44 are connectedthereto. The crank arms 40 and 42 each have a plurality of holes 46 therethrough. Wrist pin 48 is inserted through one of the holes 46 in the crank arm 40 and wrist pin 50 is inserted through a hole 46 in crank arm 42. The pitman 30 is attached to the wrist pin 48, and pitman 32 is attached to the wrist pin 50. Each of the pivot pins 34 forms a connection between each of the

pitmans

30 and 32 so the pitmans may be swung outward or moved laterally. Therefore, if the wrist pin 48 or 50 is to be moved from one hole 46 to another, this is a simple operation inasmuch as the pitman may be swung outward or moved laterally to accomplish this task. Also, if the bearing between the pitman and the wrist pin needs maintenance or replacing, this is an easy task because the pitman can be swung outward, which is to say moved laterally.

The pump jack, as described to this point, is old, well known, and commercially available on the market.

To practice my invention, I attach clamp 52 to pitman 30 and clamp 54 to pitman 32. Each of the clamps has a body and a cap so they may be readily removed or attached to the pitmans. The body of each of the

clamps

52 and 54 has socket 56 therein. The socket is an elongated, cylindrical bore, the axis of the bore is parallel to the pitman to which it is attached. Conveniently, the sockets are on the inside portions or the facing portions of the

pitmans

30 and 32.

Safety bar or brace bar or crossbar 58 extends from the pitman 30 to the pitman 32. The bar has foot 60 on each end thereof which extends through the elongated socket 56. Each foot 60 forms a snug fit within the socket 56. However, this is not to say that the feet cannot be readily removed by hand from the sockets. At the bottom of each of the feet 60, there is drill hole 62, which accommodates cotter 64. Analysis will show that the

clamps

52 and 54 with the sockets 56 maintain the bar 58 at right angle to the pitman. Also, with the bar in place, each of the pitmans is maintained at right angle to the crossbeam 28. l.e., the pitmans are connected together to maintain a right angle between each of the

pitmans

30 and 32 and crossbeam 28. Therefore, if if one of the pitmans accidently comes loose from one of the wrist pins 48 or 50, there will be no damage inasmuch as there will be no pressure to pull the walking beam out of alignment so the end of the horsehead 16 of the walking beam 18 is still correctly aligned with the packing gland 20 of the well. However, if maintenance upon the wrist pins or wrist pin bearings is necessary, the safety bar 58 may readily be disconnected merely by removing the cotters 64 and lifting the bar by hand from the sockets 56 and the

clamps

50 and 52. With the safety bar removed, the wrist pins may be removed as simply as before my invention was attached thereto.

Therefore, it may be seen that l have obtained the safety features of having the pitmans rigidly connected together, but have maintained the simplicity of maintenance in having pitmans adapted to swing outward.

The embodiment shown and described above is only exemplary. I do not claim to have invented all the parts, elements or steps described. Variousmodifications can be made in the construction, material, arrangement, and operation, and still be within the scope of my invention. The limits of the invention and the bounds of the patent protection are measured by and defined in the following claims. The restrictive description and drawing of the specific example above do not point out what an infringment of this patent would be, but are to enable the reader to make and use the invention.

I claim as my invention:

1. In a pump jack having a. a sucker rod, adapted to extend deep within the earth, attached to one end of b. a walking beam, which is pivoted atop c. a sampson post,

d. a main shaft driven by e. a prime mover,

f. two crank arms on the main shaft,

g. a crossbeam on the other end of the walking beam,

h. two pitmans connecting the crank arms to the ends of the crossbeam, and

j. a laterally yeilding joint at the connection of each of the pitmans to one of the ends of the crossbeam;

k. the method of maintaining the parts defined above in alignment in the event one of said pitmans disconnects from its crank arm comprising:

m. connecting said pitmans together to maintain a right angle between each pitman and the crossbeam, and

n. disconnecting the pitmans prepatory to intentionally o. disconnecting either pitman from its crank arm.

2. In a pump jack having a. a sucker rod, adapted to extend deep within the earth, attached to one end of b. a walking beam, which is pivoted atop c. a sampson post,

d. a main shaft driven by e. a prime mover,

f. two crank arms on the main shaft,

g. a crossbeam on the other end of the wasking beam,

h. two pitmans connecting the crank arms to the ends of the crossbeam, and

k. the improved safety guard comprising:

m. a bar extending from one of said pitmans to the other, and

ii. an elongated socket on each pitman,

o. a portion of the bar in the socket so that p. said bar is rigidly connected to each pitman to maintain a right angle between said pitman and bar, thereby maintaining a right angle between each pitman and the crossbeam.

3. The invention as defined in claim 2 with additional limitations of q. said socket is a cylindrical bore in r. a clamp attached to each pitman with the axis of the bore parallel to the pitman.

Claims

1. In a pump jack having a. a sucker rod, adapted to extend deep within the earth, attached to one end of b. a walking beam, which is pivoted atop c. a sampson post, d. a main shaft driven by e. a prime mover, f. two crank arms on the main shaft, g. a crossbeam on the other end of the walking beam, h. two pitmans connecting the crank arms to the ends of the crossbeam, and j. a laterally yeilding joint at the connection of each of the pitmans to one of the ends of the crossbeam; k. the method of maintaining the parts defined above in alignment in the event one of said pitmans disconnects from its crank arm comprising: m. connecting said pitmans together to maintain a right angle between each pitman and the cross-beam, and n. disconnecting the pitmans prepatory to intentionally o. disconnecting either pitman from its crank arm.

2. In a pump jack having a. a sucker rod, adapted to extend deep within the earth, attached to one end of b. a walking beam, which is pivoted atop c. a sampson post, d. a main shaft driven by e. a prime mover, f. two crank arms on the main shaft, g. a crossbeam on the other end of the wasking beam, h. two pitmans connecting the crank arms to the ends of the crossbeam, and j. a laterally yeilding joint at the connection of each of the pitmans to one of the ends of the crossbeam; k. the improved safety guard comprising: m. a bar extending from one of said pitmans to the other, and n. an elongated socket on each pitman, o. a portion of the bar in the socket so that p. said bar is rigidly connected to each pitman to maintain a right angle between said pitman and bar, thereby maintaining a right angle between each pitman and the crossbeam.