US1891552A - Quick return straight line pump jack - Google Patents

Description

Dec. 20, 1932.

MCCROSKY QUICK RETURN STRAIGHT LINE PUMP JACK Filed Dec. 18, 1931 i .1 /r Iig 4a se /6 4/ ||l j! 1 "A l I r||||||| l .I

27 m JHM HIHHIIII 'IHII 1 nl/HM Patented Dec. 20, 1932 BET VAIIABLE copy UNITED STATES FREI) B. MCCROSKY, F WALNUT PARK, CALIFORNIA QUICK RETURN STRAIGHT LINE PUMP JACK .Application led December 18, 1931. Serial No. 581,826.

My invention relates to improvements in l pump jacks.

An important object of my invention is to provide an improved pump jack, the paramount feature of which includes a straight line pumping stroke and a quick return motion of the pumping parts at the end of the stroke.

In addition to the foregoing object I desire 19 to point out other salient features which are incorporated in my invention which are new and novel, and are well adapted for use in the oil pumping industry. These features include a trapeze sling for the polish rod, which eliminates the heavy mule-head, thus providing for less wear on cables, greater freedom of polish rod, greater ease to swing cables in and out of play, together with means to adjust the walking beam to permit of ample space whereby to withdraw the rods from the well.

Another novel feature is the provision of improved supporting, balancing and counterbalancing means of the walking beam and its cooperating parts.

Still other objects, advantages and features of invention will hereinafter appear.

In the drawing accompanying I have o shown what constitutes, in general, a pre- 9 ferred embodimentof my inventiomwhich may, however, be used in still other branches of mechanics than that in connection with which itis disclosed, and I do not wish to be o: lilnited to the forms embodied, since permissible changes may he resorted to without departing from the scope of the invention as hereinafter claimed, and such changes and modifications are included within its scope.

IVith'reference to the drawing:

Fig. 1 is a perspective. view of a pumping unit containing an embodiment of my invention.

Figs. 2 and 3 are diagrams which display relative relation of parts near the beginning and ending of the pumping stroke whereby to depict the quick return action ofthe pump.

Figs. 4 and 5 show a modification and also display respectively the relative postions of q the walking beam counter-weight at the limited swing of the pitman.

`2 is a double reduction' speed reducer pump- Fig. 6 is a section taken on the line 6 6 of In the drawing the derrick 1 is supported by a derrick Hoor 2. Mounted on said floor serves as the band-wheel shaft and to it is 65 keyed the crank 7. The pumping unit 3 is a self contained pumping unit having all gears enclosed and running in a bath of oil. The crank has four different lengths of stroke which permits the operator to adjust the capacity of the machine to that of the well without changing the number of strokes per minute, and there is further provided means for finer adjustment as will hereinafter be pointed out. IYhis feature is particularly desirable When there is a direct connection of the motor and machine.

Beyond the wrist pin holes of the crank is secured a weight 8, said weight being adapted for cooperation with a like balance 9 in combinatiodwith the walking beam 10 or with the weight 9a of Figs. l and 5.

To the crank 7 is fastened one end of the pitman 11 by means of a wrist pin 12. the other end of said pit-man being fastened to a .pin 13 pivotally swung in a link 14 oscillative with respect to a shaft 15 journaled in bearings 16 fastened to the derrick frame 1. The link 11 is provided with a plurality of holes 17, which taken in conjunction with the holes 18 in the crankgprovide for minute adjustment for regulating the pumping stroke.

Centrally of the ptman is a boxed-in aperture 19 ,through which the walking beam 20 projects and within which is mounted the roller bearing wheel 21 by means of the pin 22. The walking beam 2O is liltingly mounted upon a shaft Q?, at substantially its midlength. Said shaft is journalled in pillow blocks S24 which are supported by the derrick shown conveniently near their limiting position. V

4The walking beam 20 is provided with a recessed face y26 that forms a track upon which the wheel 21 plays on the pumping and return stroke said track being substantially in line with the axis upon which the walking beam is tiltingly mounted. Theapproximate beginning and ending of the stroke is diagrammatically shown in Figs. 2 and 3. The depressed character of the track 26 safeguards the walking beam against edge-wise displacement at its working strain required. From Figs. 4, 5 and 6 it will be seen how I vary the effect of the weight on the quick return stroke while the pumping /rods' are being lowered.

Referring to the modification .shown in Figs. 4 and 5 and 6, on the beam 10 I fasten racksV 28 and movable on said racks are the f, pinions 29 mounted on the shaft 31 journalled in the boxed-in aperture 19, there being a bearing roller 30 interposed between the two pinions yet integral therewith, said roller resting upon the walking beam track rail- I26a secured to the upper side of the walking beam'.

The head of the beam 20 is fastened byY a pin 27 to a link 37, and said link is pivotally swung from a pin 38 in a fulcrum link 29 ,oscillative upon the shaft 40 journalled in bearings 41 fastened to the derrick frame.

The distance between the pivot pins of the link 39 is the same as the distance between pin 27 and axis of the shaft 23, and the suspension l bar 42 to which the trapeze cables 43 are fastened, is placed at the mid-length of the link 37. Hence the polish rod 44, fastenedat the mid-length of the spreader bar 45, will be elevated and lowered in a straight line as the A `crank 7 rotates to reciprocate the wheel 21 'on the surface of the beam 20. The same equalization will result with'the modification shown in Figs. 4 and 5.

A turnbuckle (not shown) could be provided on one of the cable lines 43 to assure the operator of equal tension on other lines while pumping.

Referring to the modification shown in Figs. 4 to 6, the walking beam 10, pivotally supported at 10a, is provided with a double rack 28 which forms -a track whereon the double cog wheel 29 travels. Said track has a central tread portion 26a upon which bears a roller portion 30 which is located between and preferably formed integral with the two edges of the cog wheel 29.

25 which support pivot under the heavy' Said double cog wheel 29 is housed within a box or yoke 19a with which the pitman 11a is provided at a point intermediate its .pivotal mountings which are not shown in Figs. 4 and 5, but which it is to be understood are the same as illustrated in Fig. 1. The walking and weight 9a causes the position of said v weight to be automatically adjusted during the operation of the walking beam in such a manner as to vary the counter-balancing effect of said weight so that it will produce the `desired counter-balancing effect during all positions of the walking beam. 4

In Fig. 2 is diagrammatically shown the position of the parts at the beginning of the pumping stroke. The counter-balancing weights are not shown in this view, but it will be readily seen that as the crank 7 proceeds to move in' the clock-wise direction its weight 8 (Fig.` 1) will most effectively aid the pumping stroke produced while at the same time the weight 9 (Fig. 1) will, providing the modification shown in Figs. 4 and 5 be used, be in the extended position where it will effectively supplement the power required for the pumping stroke. In Fig. 3 the parts are in the position they assume at the beginning of the down stroke where power is not required but additional speed is desired. In this position of the parts the weight 9a will be retracted to the position shown in Fig. 5 where it will exert minimum opposition to the upward movement of the outer end of the walking beam 10.

I claim:

1. In a quick return stroke construction for pumps, a driving shaft, a crank fixed to said shaft, a pitman having one of its ends operatively connected with said crank to be reciprocated thereby, a link adjustably and pivotally connected with the other end of said pitman, a support whereon saidlink is pivotally mounted, a polish rod, a walking beam pivotally supported between its ends, its inner end being connected with said polish rod, and having its outer end portion extending transversely and loosely through said pitman, said pitman having a shifting engagement with the outer portion of said walking beam to regulate the upstroke of the pump, said shifting engagement being nearest to the pivotal support of said walking beam during the down stroke of the pump to permitan accelerated down stroke, and means adapted to operatively connect the inner end of said walking beam with said polish rod.

Q. In a quick return stroke construction for pumps. a driving shaft. a crank fixed to said shaft. a pitman having one of its ends operativellv connected with said crank to be reciprocated thereb'v. a link adjustablv and pivotallv connected with the other end of said pitman. a support whereon said link is pivotall v mounted. a polish rod. a walking beam pivotalltv supported between its ends. its inner end being connected with said polish rod. and having its outer end portion extending transversely and loosely through said pitman. said pitman having a shifting engagement with the outer portion of said walking beam to regulate th'e upstroke of the pump. said shifting engagement being nearest to the pivotal support of said walking beam during the down stroke of the pump to permit an accelerated down stroke. and means adapted to operativel)v connect the inner end of said walking beam with said polish rod. said walking beam having a depressed track along its upper side. said pitman having anti-friction means adapted to travel along said track.

3. In a quick return stroke construction for pumps. a Walking beam having an upwardlwv directed face with a recessed portion. said recessed portion forming a track. a pitman to operate said walking beam. and an anti-friction roller carried b v said pitman and positioned to engage said track to depress the portion of said walking beam whereon said track is formed.

4. In a quick return stroke construction for pumps. in combination. a walking beam. an upright pitman having a transverse aperture extending through it between its ends. and an anti-friction roller mounted upon said pitman within said aperture and positioned to engage. travel along and depress a portion of said walking beam which extends through said aperture.

5. In a quick return stroke construction for pumps. in combination. a Walking beam provided with an upwardlyv facing rack which extends therealong. a pitman. a pivotal connection for one end of said pitman, a crank arm to which the other end of said pitman is pivotall)v connected. a cog wheel carried bv said pitman intermediate its ends. said wheel being constructed and arranged to engage and travel along said rack to operate said walking beam during the upstroke of the pump. a weight mounted upon said walking beam and movable lengthwise thereof. and

means eccentrieallv connecting said wheel with said weight to adjust the position of said weight in order to var)7 automaticallv the counter-balancing effect of said weight dure ing the operation of said walking beam.

6. In a quick return stroke construction for pumps. in combination. a walking beam provided with an upwardly facing double rack which extends therealong, a pitman, a pivotal connection for one end of said pitman, a crank arm to which the other end of said pitman is pivotally connected, a double cog wheel carried b v said pitman intermediate its ends to travel along said double rack, said walking beam having a tread portion between the two parts of said rack and said cog wheel having a central roller portion to engage said tread portion to bear upon said walking beam during the up-stroke of the pump. and means eccentrically connecting said wheel with said weight to change the position thereof to vary automatically its counter-balancing effect.

i'. In a quick return stroke construction' for pumps. in combination. a walking beam provided with an upwardly facing rack which extends therealong', a pitman. a pivotal connection for one end of said pitman, a crank arm kto which the other end of said pitman is pivotallv connected, a cog wheel carried b'v said pitman intermediate its ends, said wheel being constructed and arranged to engage and travel along said rack to operate said walking beam during the up-st-roke of the pump. a weight mounted upon said walking beam and movable lengthwise thereof. a crank carried bv said wheel. and a connecting-.rod connecting said crank with said weight in order to vary automatically the counter-balancing effect of said weightduring the operation of said walking beam.

8. In a device of the character described,

a frame. a walking beam pivotallyv supported thereon. a fulcrum link having one end pivotall v fastened to said frame, a pendant link having its upper end pivotedto the free end of said fulcrum link. the lower end of said pendant link being pivoted to said walking beam. a polish rod. and means connected with said pendant link at substantially its midlcngth whereby said polish rod is suspended therefrom.

9. In a device of the character described, a frame. a walking beam pivotally supported thereon. a fulcrum link having one end pivotall v fastened to said frame. a pendant link having its upper end pivoted. to the free end of said fulcrum link. the lower end of said pendant link being pivoted -to said walking beam, a polish rod, and a trapeze connected with said pendant link at substantially its mid-length whereb)Y said polish rod is suspended therefrom.

FRED B. 'MCCROSKY-

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