US2355054A

US2355054A - Pull rod carrier

Info

Publication number: US2355054A
Application number: US346114A
Authority: US
Inventors: Richard H Carr
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-07-18
Filing date: 1940-07-18
Publication date: 1944-08-08
Anticipated expiration: 1961-08-08

Description

Aug. 8, 1944. R H. CARR PULL ROD CARRIER Filed July 18, 1940 2 Sheets-Sheet l INVENTOR. Richard H. Carr BY My A? A TTORNEY.

Aug. 8, 1944. R. H. CARR PULL ROD CARRIER Filed July 18, 1940 O INVENTOR.

Richard H Carr BY W ,vtg? ATTOR EY.

Patented Aug. 8, 1944 PULL ROD CARRIER Richard H. Carr, Evanston, Ill., assignor, by

mesne assignments, to Allen M. Rossman, Wilmette, Ill. 1

Application July 18, 1940, Serial No. 346,114

6 Claims.

This invention relates to methods and apparatus for mechanical power transmission lines in which the lines reciprocate substantially horizontally and thus transmit power from a single source to a number of distant points. The invention is more particularly concerned with improved pull rod carriers and methods of reducing friction in the transmission of power from a central source to multiple oil well pumping operations by means of pull rod lines.

When a producing crude mineral oil well has been successfully completed, the well may produce oil under its own pressure for a period of time varying between wide limits and depending upon a number of factors, perhaps the most important of which is the pressure inherent in the stratum from which the oil is produced. However, by far the greatest volume of oil is produced and brought to the surface with the aid of various types of mechanical lifting methods some of the more common of which are bailing, swabbing, pumping and air-lifting. Of these various methods, pumping is decidedly the most prevalent, probably because of economy and simplicity of the operation. These pumps are generally oper ated from central power plants equipped with eccentric drives, the power being transmitted through surface lines consisting of metal rods attached to the eccentric and which are caused to reciprocate, thus operating the oil well pumps by means of pumping jacks. These strings of iron rods are generally referred to as pull rod lines, or simply as rod lines. This system of pumping oil wells is well known in the art. By this system a large number of Wells, for example, from approximately 2 to 30, may be successfully pumped with one central power plant, the exact number depending largely on the power developed at the central power,-diameter of wellitubing, depth of formation from which the oil is brought to the surface, the distance of the wells from the central power and power loss between the eccentric of the central power and the well pumping jack. This invention is particularly concerned with methods and apparatus for decreasing the power loss inherent in present methods of operation. 7

Pull rod lines are generally supported at intervals of 15 to 40' feet by short wooden posts or stakes driven into the ground and having grooves cut in the head in which the rods reciprocate. In some instances these grooves may be lubricated in order to reduce'the friction, but the use of lubricants has not shown appreciable savings in power, possibly due to difficulty of maintaining the lubricant on the crude apparatus generally used. The

friction losses of power transmission by this method, even when the grooves are lubricated, are very large. The usual length of horizontal travel of the rod line is about 30 inches to inches, the usual diameter of the rods about to 1 and the approximate weight ,per 100 feet, 200 pounds. Tests carried out on rod line power transmission by the method just described show that the average friction loss per 100 feet of /8 rod line is approximately 0.128 horsepower. When it is considered that rod lines may vary in length from about 100 feet to approximately 3000 to 3500 feet, it will be seen that the friction losses may be very large. These same tests show that the average power transmission efficiency of rod lines between the eccentric of the central power and the well is approximately 60%, the remaining 40% of the power applied. being consumed in overcoming the sliding friction of the movement of the pull rodsin the grooved supporting posts. This means that excess power to the extent of 67% of the power required at the well, must be applied to each rod line attached to the central power. When it is consideredthat wells are generally pumped over a period of several years,it is apparent that the total frictional power loss due to sliding friction of the reciprocating rods is tremendous.

I have now found that this frictional power loss may be greatly reduced and extensive economy of operation efiected by supporting the rod line on bearing blocks capable of straight line motion or motion closely approximating straight line motion. In this way the friction of the horizontal reciprocating movement of the pull rodline may be' reduced to'a very small fraction of the amount formerly encountered. Q

It is an object of this invention to provide an improved apparatus and method for transmitting power through horizontal reciprocatingrod lines. Another object of this invention, is to provide apparatus and method for reducing the friction losses of horizontal, reciprocating power transmission rod lines. p r

A still further object of the invention is to rovide means for freely supporting a reciprocable rod at a plurality of points by means of straight line carriers so that if breakage or other accident occurs at some point in the rodwhile under tension, the rod will not-injurethe carriers.

These and other advantages will be apparent from the following description taken in conjunc: tion with the accompanying drawings of which Figure 1 is a front elevationalview of one embodiment of a pull rod carrier in accordance with the invention.

Figure 2 is a plan view of the device shown in Figure 1.

Figure 3 is an end elevational view of the device shown in Figure 1.

Figure 4 is an enlarged isometric view of a supporting block forming part of the device shown in Figure 1.

Figure 5 is a plan view of a pull rod line connected to a power source and to a pumping jack, the rod being supported by a plurality of devices corresponding to that shown in Figure 1; and

Figure 6 is a front elevational view of the apparatus shown in Figur 5.

Referring to the drawings, numeral I indicates generally a pull rod carrier. The numeral 3 indicates a pair of spaced posts or iron pipes which are firmly driven into or anchored in the ground along the line of the rod it is desired to support. Upon the posts or pipes 3 are placed elongated, rectangular, wooden blocks 5 and 1. The blocks each have a hole 9 drilled partially through from the bottom upward, of approximately the same diameter of the posts or pipes 3 and the posts or pipes are inserted into the holes. Blocks 5 and 1 are retained in spaced relation by means of a pair of tie rods II and I3 which are inserted through holes I4 bored horizontally through the blocks near the ends thereof. The rods H and I3 are retained in place by means of washers I5 and cotter pins l1.

Blocks 5 and 1 each have a hole l9 drilled therethrough horizontally in a direction at right angles to and above the holes l4. The holes l9 act as bearings for the pivotally mounted horizontal arms 2| of rods 23. The arms 2| are retained in place in the holes, I?! by suitable washers and cotter pins placed on the arms at each end of the block. The rods 23 are bent upwardly at 25 to an angle such that the arm 21 makes with the arm 2| an oblique angle of about 80. The rods 23' are bent near the upper end at 29 to form another horizontal arm 3| which is parallel to and directly above the .arm 2| but somewhat .shorter than the latter. 7 A rectangular wooden block 33 is pivotally mounted on each of the arms 3| by inserting the arm through a horizontal hole drilled through the block near the bottom thereof. The holes in the blocks 33 provide bearing surfaces for the arms 3|. The blocks 33 are maintained in place on the arms 3| by means of washers and cotter pins placed on the arms at each end of the block. Blocks 33 are preferably placed on the arms 3| sothat they lie in a perpendicular plane withthe'p'osts 3.

The blocks 33 are held i'n's'paced relation by meansof horizontal tie rod 35 which is inserted ,through. horizontal holes boredf through the blocks near the upper end thereof above and in a direction at right angles to the'holes' through which the arms 3| are inserted. Suitable washers and cotter pins placed oneach'side' of the blocks hold the blocks in place on the tie rod 35. The distance .between the blocks 33 as shown on the drawings is less than the distance between the'blocks 5 and 1-.

A rod 31 is rigidly suspended from and at right angles to the rod 39 midway between the blocks 33. The rod 31 may be welded or otherwise joined to the rod 35. 'As shown more particularly in Figure 3, the rod 31 is bent at its lower end to form a horizontal arm 39 upon which is pivotally mounteda block 4L The arm 39 is insertedin a hole 40. drilled horizontally through. the block 4| and the block 4| is retained on the arm by means of washers and cotter pins placed on either side of the block. The rod 31 is somewhat shorter than the arms 21. As is apparent from Figure 3, the rod 31 does not hang vertically from the tie rod 35, but is suspended at a small angle from the vertical so that the block 4| may be supported on the arm 39 in the same vertical plane as the blocks 33 and posts'3.

Block 4|, as more particularly shown in Figure 4, has an arcuate groove 43 in the upper face thereof running in the same direction as the hole 40. The groove 43 is adapted to receive the rounded portion of a U-bolt 45 which is rigidly fastened to a pull rod 41 by means of the plate 49 and nuts 5|. The U-bolt 45 and groove 43 provide a means of freely supporting the pull rod 41 on the block 4| so that the rod 41 will not readily slip oif the block but at the same time the rod can be easily thrown free of the block 4| in event breakage of the rods occurs while under tension. Breakage of the rod while under tension causes the rod to fly upward with great force and would tear the carriers loose or severely damage them if the rod were fastened to the supporting block 4|. Since breakage of the pull rod is not an infrequent occurrence, it is extremely important that the pull rod be freely supported.

The

wooden blocks

5, 1, 33 and 4| are all oilsoaked so as to provide bearing surface for the rods which are pivotally mounted in the holes bored in the blocks. It will be apparent that the device is pivotally mounted at the

points

53, 55, 51 and 59 and the block 4| is also pivotally mounted on the arm 39 at 63. The lengths of the arms 23, ll, I3, 35 and 31 are such that the block 4| is adapted to reciprocate or oscillate along a substantially straight line over a limited stroke. In Figure 1 there is shown in dotted lines the position of the carrier at two different positions in its straight line stroke.

In order to obtain a substantially straight line stroke of approximately 30 to 40 inches, a device having the following dimensions is required:

Inches Distance from 53 to 55 30 Distance from 53 to 51 27 Distance from 55 to 59 27 Distance from 51 to 5L 15 Vertical distance from 3| to 63 21 With dimensions corresponding to those above given, the point 63 will not deviate from the horizontal straight line more than /4 above or below over a stroke under 40".

In'order to obtain a longer straight line stroke it is necessary to build a device of larger dimensions but substantially the same ratio of lengths between points should be maintained.

The device in accordance with my invention can be constructed out of old sucker rods in diameter bent to proper shape, and hardwood blocks. By so constructing the device, great economy can be efiected. It will be apparent that the device can be constructed out of other materials and that the pull rod may be freely supported on .the carrier block in other ways than those shown and described without departing from the invene tion.

In Figures 5 and 6 there is shown the manner which a pull rod line, connected at one end to an eccentric .65, oscillated by a suitable source of power, and. at the other end. to a pumping jack 61, is supported at spaced points by straight line pull rod carriers I in accordance with my invention. The rod line 4! may be supported at intervals of approximately 15 to 40 feet. The

. distance above the ground at which the rod line is supported will depend on the height of the eccentric and pumping jack and, and to some extent, the nature of the terrain.

By using,straight line carrier supports of the type herein described, friction loss is greatly reduced over that which is experienced in the use of conventional dollheads so that a greater number of wells can be pumped from a single source of power or a much smaller prime mover can be used to furnish the power required. Moreover, by freely supporting the pull rod on the carrier blocks, damage to the carriers is avoided when breakage occurs in the line.

It will be apparent that before starting operation of the pull rod it is necessary in order to realize the full benefits of the invention, to center each carrier on the line so that when the arm 37 is exactly midway between the arms 23 as shown in Figures 1 and 6, the pull rod is in the middle of its stroke. If this is not done, the support will not move in a substantially straight line but will tend during one part of the stroke to move in an upward direction, thereby defeating in part the purpose of the carrier.

As used in the specification and claims, the expression straight line motion means motion in which a straight line is not deviated from more than A" in a vertical direction.

I claim:

1. A device of the character described comprising a linkage having a point thereon adapted to oscillate over a limited distance along a substantially straight line, supporting means fastened to said linkage at said point for freely supporting a reciprocable rod line, and means adapted to be secured to a reciprocating rod line and cooperating with the supporting means for centering the supporting means with respect to the rod in the direction of reciprocation of the rod.

2. A device of the character described comprising a pair of upstanding arms mounted at their lower ends on fixed pivots, a support suspended between said arms by movable pivots in such manner as to be capable of oscillatin for a limited distance along a substantially straight line,

said support being adapted to freely carry a re ciprocable rod on its upper surface and means associated with the support for receiving a, projection on a reciprocable rod for centering the support with respect to the rod in the direction of reciprocation of the rod.

3. A device of the character described comprising a linkage having a point thereon adapted to oscillate over a limited distance along a substantiall straight line and means fastened to said linkage at said point for freely supporting a reciprocable rod line and interlocking with the red line in such manner that sliding of the rod line on the support will not occur when said means oscillates.

4. A device of the character described comprising a pair of upstanding arms mounted at their lower ends on fixed pivots, means suspended between said arms by movable pivots for supporting a reciprocable rod, said means being capable of oscillating over a limited distance along a substantially straight line, said means also being adapted to freely support said red, and means for interlocking said first means with said rod to prevent relative sliding of said rod with respect to said first means when said first means oscillates.

5. In combination a substantially horizontal reciprocable rod, a projecting member rigidly fastened to said rod, a carrier for said rod having as a part thereof, a support adapted to oscillate over a limited distance along a straight line and a recess on the upper surface of said support in which said projecting member is adapted to seat.

6. In combination with a reciprocable pull rod, a pull rod carrier for freely supporting the rod, said carrier including a support upon which said rod is adapted to rest, said support being suspended by linkage which guides said support to oscillate along a substantially straight line, the carrier being openon one side and the pull rod being freely supported on said support so that the rod may be removed from the support and carrier by lifting and moving the rod laterally to permit lowering of the rod from the carrier, and means for interlocking said support with the pull rod to prevent relative sliding between the rod and the support in the direction of reciprocation of the rod.

RICHARD H. CARR.