US2274937A - Resilient counterbalancing device - Google Patents

Description

March 3, 1942. H. H. RAULERsoN 2,274,937

' RESILIENT COUNTERBALANCING DEVICE 2 Sheets-Sheet 1 Filed Dec. 19, 1939 "MEN INVENTOR. Hardq H. RQU\erSOn.

March 3, 1942. H.4H. RAULERSON RESILIENT COUNTERBALANCING DEVICE Filed Dec. 19, 1939 2 Sheets-#Sheet 2 INENTOR. 'clr'cj H RauLer'son.

Patented Mar. 3, 1942 UNITED STATES PATENT OFFICE RESILIENT COUNTERBALANCING DEVICE Hardy H. Raulerson, Long Beach, Calif.

Application December 19, 1939, Serial No. 309,981

(Cl. 'I4-592) 7 Claims.

This invention relates to improvements in spring counterbalance devices.

The general object of the invention is to provide for counterbalancing the weight of a pump sucker rod.

A more specic object of the invention is to provide an improved spring operated counterbalancing means for use with pump jacks of various kinds.

A further object of the invention is to provide a spring counterbalancing device including means whereby the force exerted by a coiled spring normally partly expanded remains the same during a predetermined expansion and contraction from the normal position.

Other objects and the advantages of this invention will be apparent from the following description taken in connection with the accompanying drawings, wherein:

Fig. 1 is a side elevation of a pump jack embodying the features of my invention;

Fig. 2 is a top plan view of the pump jack shown in Fig. 1;

Fig. 3 is a section taken on line 3-3, Fig. 1;

Fig. 4 is a fragmentary section taken on line 4-4, Fig. 1;

Fig. 5 is a section taken on line 5-5, Fig. 3;

Fig. 6 is a fragmentary vertical section through a water well pump tower with my invention operatively mounted thereon to work in conjunction with the pump rod;

Fig. 7 is a section taken on line 'I'I, Fig. 6;

Fig. 8 is a side view of one of the pulleys of the device in Fig. 7 with the cam member removed;

Fig. 9 is a section taken on line 9--9, Fig. '7;

Fig. 10 is a side elevation of a modified form of my invention; and

Fig. 11 is a top plan view of the device shown in Fig. 10.

Referring to the drawings by reference characters I have shown my invention embodied in a pump jack which is indicated generally at I0.

My invention is applicable to various types of pump jacks. The pump jack shown includes a frame indicated generally at I2 which adjacent the upper end supports a walking beam I3. One end of the beam I3 includes a spoke portion I4 each side of which includes a trunnion I5 mounted in a bearing I6 on the frame. The opposite end of the beam I3 is pivotally connected as at I1 to a cross head I8 which includes a pivot I9 pivotally supporting a fitting 20 which supports a sucker rod 2I.

On each side of the beam I3 I provide a guide arm 22 which includes a trunnion 23 supported in a bearing 24 on the frame I2. The opposite end of each of the guide arms 22 is pivotally connected as at 25 to the cross head IB.

The beam I3 is adapted to be actuated by a pair of link members 26 positioned one on each side of the beam and pivotally connected thereto adjacent their upper ends as at 21. Adjacent their lower ends the links 26 are each pivotally connected by a pin 28 to one end of a crank arm 29. Each crank arm adjacent the other end includes a trunnion 36 positioned in bearings 3| on the frame I2.

The pins 28 extend inward and are each mounted in an arm member 32 mounted on a gear 33. rEhe gear 33 meshes with a reduced gear 34 which has arm members 35 mounted thereon. Spaced from the arms 35 the device includes crank arms 36 which include trunnion portions 3l mounted in bearings 38 on the frame I2. Adjacent their cuter ends each crank arm 36 is connected to the adjacent arm member 35 by a pin 39. Mounted on each of the pins 39 I provide a sleeve 40 which includes a projecting eye member 4I.

One of the trunnions 3l extends outward beyond the frame I2 and has a worm gear 42 thereon which meshes with a worm pinion 43 on the armature shaft 44 of an electric motor 45. From the foregoing it will be apparent that when the motor 45 is operating the worm pinion 43 will rotate the shaft 3'I on whichit is mounted which in turn will rotate the gear 34 to thus rotate the gear 33. As the gear 33 rotates the arm members 29 and 32 move with it and swing the pins 28 about the axis of the trunnions 30 thus vertically reciprocating the link members 26.

As the link members are thus moved they move the beam I3 up and down about the axis of the trunnion I5 thus vertically reciprocating the cross head I8 and the sucker rod 2|.

Spaced from the gear 34 opposite the gear 33 I provide a transverse shaft 46 which is mounted in `bearings 41 on the frame I 2. Mounted on the shaft 46 I provide two sets of pulley units 48 each of which is secured to the shaft by a key 49. Each of the units 48 includes a central grooved pulley 50 with a grooved cam member 5I on each side. The working surface or bottom 52 of the groove of each cam member is shaped to include a portion spaced a predetermined distance from the center and then following a helical path approaching the axis of the shaft 46. (See Fig. 5.)

Each of the pulleys 50 has one end of a cable 53 secured thereto whence the cable extends over the pulley and is connected by a link 54 to the eye 4I of one of the sleeves 40.

Each of the pulleys 58 have a cable 55 extending through a suitable aperture therein as shown in Fig. 3 and the two lengths of the cables 55` extend over the outer ends of the cam members 5| and extend towards the gear 34 where the ends of both cables are connected by links 56 to plates 51.

Each of the plates 51 has one end of a coiled spring 58 connected thereto while the opposite end of each of the springs is anchored to a lug member 59 through the medium of a turnbuckle 60.

The cam members 5| are arranged so that the extremities thereof are below the axis of the shaft 46 when the crank arms 35 and 36 extend horizontally towards the shaft 46 as shown in Figs. l and 2. In this position of the cam members the springs are under a predetermined amount of tension which is suilicient to balance the Weight of the sucker rod 2i.

Thus when the motor 45 operates to reciprocate the sucker rod as previously described and the crank arms 35 and 36 swing away from the shaft 46, the cables 53 move with them and rotate the pulleys 58 and cam members 5| in a clockwise direction approximately one quarter revolution. As the cam members thus move the cables 55 wind against the working surface 52 and extend the springs 58. Due to the shape of the working surfaces 52 of the cams as the cables wind thereon they move towards the axis of the shaft and thereby the leverage arm is decreased. Thus substantially the same resistance is exerted against the cables 53 at all times to counterbalance the weight of the sucker rod 2|.

The weight of the fluid pumped may be counter-balanced in any of the usual manners such as by properly positioning a weighted (not shown) on the shaft 30.

In Figs. 6 and '1 I have shown my invention applied to a windmill type of water pumping device which includes a tower frame 65 and a vertically reciprocating sucker rod 66 which may be operated by the conventional windmill.

At one side of the sucker rod 66 I provide a horizontal shaft 61 which is journaled in bearings 68 on the frame 65. Mounted on the shaft 61 I provide a pulley assembly indicated at 69 which includes a grooved center portion 19 to receive the sucker rod 66 and grooved pulley portions 1| on each side thereof.

Mounted on the outer faces of each of the pulley portions 1| I provide a grooved cam member 12 each of which has elongated aperture 13 therein in which the shaft 61 is positioned. Each of the cams 12 is secured to its respective pulley by a pair of bolts 14 which are positioned in one of a set of threaded apertures 15 in the pulley.

Each of the cams 12 includes a working surface 16 which is dellned by the bottom of the groove therein, (see Fig. 9). The working surfaces of the cams each includes an end portion positioned a predetermined distance from the axis of the cam which is connected to a portion which extends inwardly in a curve which approaches the axis of the cam. By providing a plurality of the threaded apertures 15 in the pulleys the cams may be adjusted to move the extremities thereof towards or from the axis of the shaft 61.

Cables 11 extend over the pulleys 1| with each cable having one end anchored to its associated pulley and the opposite end connected to a cross head 18 on the sucker rod 66.

Each of the cams 12 has one end of a cable 19 anchored thereto. Each cable. extends over the extremities of the working surface 16. The

opposite ends of the cables 19 are connected to a bar 8|) to which one end of a coiled spring 8| is connected. The opposite end of the coiled spring 8| is anchored to a portion of the frame 65 through the medium of a turnbuckle 82.

The cams 12 are arranged so that when the sucker rod 66 is at the limit of its upward movement the extremities of the working surfaces are farthest from the sucker rod. When the cams are in this, the initial position the spring 8| is under a predetermined amount of tension. As the sucker rod moves downward the cables 11 rotate the pulleys 1| in a clockwise direction which in turn rotate the cams. As the cams 12 are thus rotated the cables 19 wind upon the working surfaces 16 thereof against the action of the spring 8| and extend the spring. Due to the shape of the working surfaces 16 of the cams as the cables wind thereon they move towards the axis of the shaft 61 and thereby the active leverage is decreased. Thus the substantially same resistance is exerted against the cables 11 at all times.-

In Figs. 10 and 11 I have indicated a device generally at which may be used in place of the device 69. As shown the device 85 includes a central grooves wheel 86 which receives the sucker rod 66. At each side of the wheel 86 I mount a sprocket 81.

On the outer face of each sprocket 81 I provide a sprocket 88 the axis of which is positioned eccentric to the axis of the adjacent sprocket 81. The sprockets 88 each has an elongated aperture 89 therein in which the shaft 61 is positioned.

` The sprockets 88 are each secured to the sprockets 81 by a pair of bolts 90 each of which is positioned in one of a plurality of threaded apertures 9| in the sprockets. By providing a plurality of the apertures 9| the sprockets 88 may be positioned closer or farther from the axis of the sprockets 81.

The sprockets 81 each has one end of a sprocket chain 92 anchored thereto as at 93 and which extends over the sprocket and has the opposite end connected to a cross head 94 on the sucker rod 66.

Each of the sprockets 88 has one end of a sprocket chain 95 anchored thereto as at 96 and which extends downward and is connected to the spring 8|. In operation the sprockets 88 act in the same manner as the cam members 12.

From the foregoing description it will be apparent that I have provided a novel spring counterbalancing device which is simple in construction and highly efficient in use.

I claim:

l. In a counter-balance for an oscillating beam, a base, a shaft on said base, means operated by the shaft for oscillating said beam, a crank arm on said shaft, a second shaft mounted on said base and spaced from said first shaft, a pulley member on said second shaft, said pulley including a flexible member engaging portion, a flexible member having one end anchored rto said pulley and passing thereover and having the opposite end connected to said crank arm, a resilient member on said base, a second flexible member having one end connected to said resilient member, a second flexible member engaging portion rotatable with said pulley, means to secure the other end of said second flexible member to said second engaging portion, one of said engaging portions including a spiral cam surface, the relation of said cam surface and said crank arm being such that when the crank arm is nearest the second shaft the portion of the cam surface most remote from the cam axis is operatively engaged by its flexible member.

2. A pump jack including a pivoted walking beam having means thereon to engage a sucker rod, a shaft, means driven by said shaft for oscillating said beam, a crank arm on said shaft, a second shaft spaced from said first shaft, a cam member on said second shaft, said cam member including a cam portion having a spiral Working surface diminishing towards its axis, a flexible member anchored to said cam member and engaging the Working surface of said cam, a resilient member having one end connected to said flexible member and having the other end anchored, said cam member having a pulley groove therein, a second flexible member disposed in said pulley groove and having one end connected to the cam member and the other end connected to said crank arm, the relation of said cam working surface and said crank arm being such that when the crank arm is nearest the second shaft the second flexible member operatively engages the portion of the cam most remote from its axis and approaches its axis as the crank member recedes from the second shaft.

3. A pump jack including a pivoted Walking beam having means thereon to engage a sucker rod, a shaft, means driven by said shaft for oscillating said beam, a crank arm on said shaft, a second shaft spaced from said first shaft, a pulley member on said second shaft, a flexible member having one end anchored to said pulley and passing thereover and having the opposite end connected to said crank arm, a cam member, means to adjustably secure the cam member on said pulley, said cam member having a spiral Working surface, a second flexible member anchored to said pulley and engaging the Working surface of said cam, and a resilient member connected at one end to said second exible member and having the other end anchored.

4l. A pump jack including a pivoted Walking beam having means thereon to engage a sucker rod, a shaft, means driven by said shaft for oscillating said beam, a crank arm on said shaft, a sleeve member rotatably mounted on said crank arm, a second shaft spaced from said first shaft, a pulley member on said second shaft, a flexible member having one end anchored to said pulley and passing thereover and having the opposite end connected to said sleeve member, said pulley including a cam portion having a spiral Working surface, a second flexible member anchored to said pulley and engaging the Working surface of said cam, a resilient member connected at one end to said second flexible member and having the other end anchored, the relation of said cam and said crank arm being such that when the crank arm is nearest the second` shaft the second flexible member operatively engages the portion of the cam most remote from its axis and approaches its axis as the crank member recedes from the second shaft.

5. A pump jack including a base, a Walking beam pivotally mounted on said base, a shaft on said base, means operated by the shaft for oscillating said beam, a crank arm on said shaft, a sleeve member rotatably mounted on said crank arm, a shaft mounted on said base and spaced from said rst shaft, a pulley member on said second shaft, said pulley including a cam portion on each side thereof, a flexible member having one end anchored to said pulley and passing thereover and having the opposite end connected to said sleeve member, said cam portions each including a spiral Working surface, a pair of flexible members each having one end anchored at one end to one of said cam portions, a resilient member, means connecting the other end of said pair of members to said resilient member, means to anchor the other end of said resilient member, the relation of said cam portions and said crank arm being such that when the crank arm is nearest the second shaft the pair of flexible members operatively engage the portion of the cam portions most remote from the cam axis and approaches its axis as the crank member recedes from the second shaft.

6. A pump jack including a base, a Walking beam pivotally mounted on said base, a pair of shafts rotatable on said base, means operated by one shaft to drive the other shaft, means operated by the other shaft to oscillate the beam, a pair of crank arms on said one shaft, a third shaft spaced from said pair of shafts, a pair of pulley members mounted on said third shaft, each of said pulleys including a cam member on each side thereof, flexible members each having one end anchored to one of said pulleys and passing tliereover and having the other end connected to one of said crank arms, said cam members each including a spiral Working surface, a plurality of pairs of flexible members each associated with one cam, each of said pairs of flexible members being anchored at one end to its cams, a pair of resilient members on said base and means connecting each pair of flexible members to the resilient members.

'7. A pump jack including a base, a Walking beam pivotally mounted on said base, a pair of shafts rotatable on said base, means operated by one shaft to drive the other shaft, means operated by the other shaft to oscillate the beam, a pair of crank arms on said one shaft, a sleeve member rotatably mounted on each of said crank arms, a third shaft spaced from said pair of shafts, a pair of pulley members mounted on said third shaft, each of said pulleys including a cam on each side thereof, flexible members each having one end anchored to one of said pulleys and passing thereover and having the other end connected to one of said sleeve members, said cams each including a spiral working surface, a plurality of pairs of flexible .members each associated with one cam, each of said pairs of flexible members being anchored at one end to its cam, a pair of resilient members, means connecting each pair of flexible members to one end of one resilient member, means to anchor the other opposite ends of said resilient members, the relation of said cams and said crank arms being such that when the crank arms are nearest the third shaft the pairs of flexible members operatively engage the portion of the cams most remote from the cam axis.

HARDY H. RAULERSON,

Images