US2612142A - Pump jack valve control mechanism - Google Patents

Description

Sept. 30, 1952 s. v. SMITH JACK VALVE CONTROL MECHANISM 2 SHEETfS-SHEET 1 Filed April 25, 1949 JNl EN r012 5444 151. VSM/TH B y I A TTOENEY.

Sept. 30, 1952 S. V. SMITH PUMP JACK VALVE CONTROL MECHANISM Filed April 25, 1949 2 SHEETSSHEET 2 r 65 1. 2 72 86 I m s a g 97 1 O l Ia l 9 [-2 I I 56 q 61 1 as a! 7 I 55 ii i H 20 I v Q r H 7- 26 ,Q I A O m 67 'I "I 76 Q 4.- 7-? n I I t INVENTOR.

' TH, 78 BY -A77'0RNEY.

Patented Sept. 30, I 1952 UNITED STATES PATENT OFFICE PUMP JACK VALVE CONTROL MECHANISM Samuel v. Smith, Lon Beach, Calif; Application Apr-i123, 1949, Serial No. 89,251

'Claims.

' 1 This invention has to pressure. operated pump jack mechanisms particularly of the type dealt with in my copending application Serial Number 14,355, filed March 11, 1948 on Well Pumping Equipment, now Patent No. 2,564,285, issued August 14, 1951, andhas for its general object to provide improved mechanismsfor actuating a pressurefluid control valve in. accordance with the travel of the jack piston. The. pump jack proper may be characterized as comprising a vertically positioned cylinder, or cylinder assembly, containing a singleor multiple piston assembly reciprocable vertically by the applied fiuid pressure to operate the work, suchras a well pump. The invention contemplates operation of the actuating fluid control valveby a mechanism employing a cam carried directly by an upper portion of the piston contained within a vertically extended housing, and operable to actuate a housing supported mechanism, the

movements of which are transmitted to the control' valve.

In accordance with its preferred embodiment,

the invention employs a pair of vertically spaced movable elements'extending from the outside of the housing intothe interior thereof for direct engageability by the piston-carried cam means. While. it is broadly contemplated thatvarious types of mechanisms may be employed for transmitting movement of saidlelement to the control valve, it is preferred to connect the elementsfor simultaneous movement, and specifically'by way of flexible. connections such as cables, the advantages of which will later develop. The inventionhas various specific objects and noveldetails, all of which will appear from the following description of a typical and illustrative embodiment of the inventionshown by the accompanying drawing, in which:

Fig. l is a general view illustratingthe pump jack proper and pressure fluid supply system;

Fig. 2 is an enlarged fragmentary view showing the position of the valve actuating parts at the start of the piston up-stroke;

Fig. 3 is. a similar view showing the positions of the parts at the start of the piston downstroke; and

Fig. 4 is a fragmentary section on line 4-4 of Fig. 2.

Referring first to the general showing of Fig. 1, the pump jack unit generally indicated at l0 and adapted to be positioned above and in axial alinement with a well bore, is shown to comprise a cylinder assembly. II containing a vertically reciprocable piston assembly l2 whichcarries do generally. withfluid I 2 andoperates the well pump rod l3. The cylinder assembly I I comprises a base 14, aninner tubular. section I5, an intermediate cylinder [6, and outer cylindrical shell I! on which is mounted thehead I8 containing annular fluid passage IS. The. piston assembly I2 comprises an outer sec: tion 20 carrying a head 2| contained within space 22 and having sliding, substantially 'fiuid tight engagement with the surfaces of the cylinder sections. I6 and H. The piston section 20 is spaced from the cylindrical shell I! at.23 tapermit communication of fluid pressurefrom the cylinder head space I9 through. the ammlar clearance at 24 to the piston face 25. As illus-. trated, the piston has sliding, fluid-tight engage-i ment at 26 within the-cylinder headIB. The pl's ton assembly includes an inner section 28 carrying a head 29 reciprocable within space 30 and having substantially fluid-tightengagementwith the cylinder sections I5 and I6. Thepump .rod I3 may besupported by the upper closed end3l, of the piston assembly, as by carrying the. rod on a removable bearing or bushing 32. I

As more fully described in my. copendingfapplication referred to above the piston assembly I2 is adapted to be operated by maintaining a constantly applied elevating pressure, specifically air pressure from receiver 33, while alternately applying fluid pressure, specifically that of oil from the reservoir 34, toreciprocate the piston assembly. More complete details concerning the pressure fluid supply system appear in theother application. For present purposes, the following description of the pressure fluid system will suffice. v

The compressed air maintained in receiver 33 at the proper pressure level required for ,-operf ar tion of the piston, is communicated through pipe 35 to the cylinder space 22 so that theair prese sure constantly exerts an elevating .force against the piston face 36.: Oil from reservoir34 is discharged by pump 31 through line-38 to amaster valve 39 which operates to alternately meet the oil under pressure through lines 40 and-4i re.- spectively to space 30 and the piston face-wand spaces I9, 23 and the piston face25. Returncil flow from the master va1ve'39 to the reservoir occurs through line 43. As will be understood. the piston assembly is-driven on its vdownstroke by the weight of rod I3, the pump parts carried thereby and. the oil pressure against thepiston face 25, all acting to overcome the resistance-of the .airpressure applied .to the piston face 36,, at least throughoutthe latter portion of; the, piston downstroke; The piston -.assembly and its. rod

are elevated by air pressure against face 36 and the oil pressure acting against the piston face 42.

The operation of master valve 39 is controlled by oil pressure communicated from line 38 through pipe 44 and lines 45 and 46, under control of a suitable pilot valve 41 which in turn is reciprocally operated by rod 48. Oil is returned from the pilot valve to the reservoir 34 through line 49. Provision may be made for controlling the hydraulic pressure at the discharge side of the pump 31 in accordance with the air pressure in receiver 33, as through the by-pass of oil from line 38 through pipe 59 into line 43, under control of a suitable regulator valve assembly 5| which in turn is controlled by air pressure communicated from the receiver through line 52.

The present invention is more particularly concerned with an improved control mechanism generally indicated at 53, for actuating the pilot valve 41 by reciprocation of its rod 48 in accordance with the travel of the piston assembly I2. Referring particularly to Figs. 2 and 3, the upper end of the piston is shown to carry an annular cam 54 having angular faces 55 and 55, which reciprocates vertically within a cylindrical housing 51 carried by and extending above the cylinder head [8. Mounted on the housing 51 are vertically spaced pairs of arms 58 and 59, each arm containing an outer end slot 69 within which is supported a pivot 6| adjustable longitudinally of the supporting arm. .The cylinder head 18 may carry a third pair of arms 62 which supports the adjustable pivot 63. Arms 58 and 59 support respectively the levers 64 and 65 mounted for swinging movement about'the pivot 61.

Arms 62 carry a link 66 which swings about pivot 63.and has an arm 61 pivotally connected at 68 with the valve actuating rod 48. Levers 64, 65 and the link 66 are connected for swinging movement together, preferably by flexible members or cables '69 and 10 having couplings H which are pivotally attached at 12 to the levers.

.Lever 64 carries at its inner end a bifurcated extension 14 extending through slot 15 in the housing 51 and pivoted at 16 to the lever proper. Swinging movement of the extension 14 in one direction relative to the body of the lever is resisted by coil spring 11 terminally connected tothe lever-carried arm 81 and the extensioncarried arm 11L Movement of the lever extension 14 is limited in the Fig. 2 position by engagement of the stop 18 with the top edge of the lever 64. The extension 14 carries a roller 19 engageable by the cam 54 to actuate the lever and connected parts, as in a manner later explained.

Lever 65 similarly carries a bifurcated extension 80 pivoted on the lever-carried pin 8| and swingable downwardly by gravity from .the solid line position established by the engagement of stop 83 with the bottom edge of the lever, to the broken line position 84. Extension 80 'projects through the housing slot 85 and carries the roller86. y g

The described lever and cable system may be balanced in any suitable manner so that the mass or weight at the right hand side of the pivots BI' and 63 will balance the weight or mass at the left hand side where the described roller assemblies are carried. Typically, cable 69 may carry a weight 88 ofsufficient mass to maintain the system in balanced condition, and thereby assure effective and unimpeded operation of the control valve. Since the valve itself is mounted the positions illustrated in Figs. 1 and 2, in which the piston assembly I2 is starting its up-stroke and the pilot and master valves 41 and 39 are positioned to deliver the pressurized hydraulic fluid through line 40 to the cylinder space 30.

Having previously been displaced to the solid line position of Fig. 2, roller 36 will be passed by the cam 54. The latter then continues its up-stroke to the point of engaging the cam surface 56 against roller 19, whereupon lever 64 is swung clockwise about the pivot 6| to shift cables 69 and 10 respectively downwardly and upwardly, and rotate link 66 clockwise to throw the valve rod 48 to the left. Thereupon the pilot and master valve positions are reversed to cause the delivery of the pressurized hydraulic fluid through line 4| to cylinder space 23, thereby initiating the piston down-stroke. As the piston approaches the lower limit of its stroke, the cam face 55 engages roller 86 (which previously had become thrown from Fig.2 position to that illustrated in Fig. 3 by the described cam actuation of lever 64) to again reverse the valve rod 48 through upward and downward displacement, respectively, of cables 69 and 10, and clockwise swinging of the levers 64, 65 and the link 66.

The roller-carrying lever extensions 14 and B0 are permitted swinging movement relative to the levers proper, in order to obviate the possibility of inadvertent actuation of the valve mechanism should for any reason either of the rollers in its intended radially outward position, project sufficiently in the path of the cam to otherwise cause the attached lever to be affected by the cam. For instance, should roller 19 after displacement to the intended Fig. 3 position, be returned sufiiciently into the path of the cam as to be engageable by the face 55 as the piston starts down, the pivotal mounting of the extension 14 will permit its downward displacement relative to and without causing movement of the lever 64. Upon travel of the cam down past the roller, the latter is returned to its illustrated position by the spring 11. Similarly, should roller 86 remain (in the aspect of Fig. 2), within the path of the cam, upon engagement by the cam face 56, the roller and its carrier may be displaced to the dotted line position 84, without aifecting the lever 65 and the connected valve control linkages.

I claim:

1. A fluid pressure operated jack mechanism comprising a vertically extending cylinder assembly, a piston assembly reciprocable vertically within said cylinder assembly, valve means for controlling the application of fluid pressure to said piston assembly, cam means carried by the upper portion of the piston assembly, a housing about the cam means and within which said cam means is vertically reciprocable, a pair of verti cally spaced pivotally movable levers carried by said housing and actuable selectively by said cam means during piston travel in opposite directions, each of said levers including an outer section and an inner section pivotally movable relative to the outer section upon engagement by the cam means during its travel in one direction, a spring resisting said relative movement of the inner section of one lever, a valve actuating element pivotally mounted to the housing in substantial vertical alinement with said levers, a pair of flexible cables interconnecting said levers and said actuating element at the outer and inner sides respectively of their individual pivotal axes so that the levers and element move in unison, and means connecting said element to the valve means.

2. A fluid pressure operated jack mechanism comprising a vertically extending cylinder assembly, a piston assembly reciprocable vertically within said cylinder assembly, valve means for controlling the application of fluid pressure to said piston assembly, cam means carried by the upper portion of the piston assembly, a housing about the cam means and within which said cam means is vertically reciprocable, a pair of vertically spaced pivotally movable levers carried by said housing and actuable selectively by said cam means during piston travel in opposite directions, each of said levers including an outer section and an inner section pivotally movable relative to the outer section upon engagement by the cam means during its travel in one direction, a spring resisting said relative movement of the inner section of one lever, a valve actuating element pivotally mounted to the housing in substantial vertical alinement with said levers, a pair of flexible cables interconnecting said levers and said actuating element at the outer and inner sides respectively of their individual pivotal axes so that the levers and element move in unison, means connecting said element to the valve means, and a counterweight carried by an outer one of said flexible cables for counterbalancing the weight of the inner ends of said levers.

3. A fluid pressure operated jack mechanism comprising a vertically extending cylinder assembly, a piston assembly reciprocable vertically within said cylinder assembly, valve means for controlling the application of fluid pressure to said piston assembly, cam means carried by the upper portion of the piston assembly, a housing about the cam means and within which said cam means is vertically reciprocable, a pair of vertically spaced pivotally movable levers carried by said housing and actuable selectively by said cam means during piston travel in opposite di-. rections, a pair of flexible cables interconnecting said levers at the two sides of their pivotal axes to interconnect them for simultaneous movement, and means for transmitting such movement to said valve means.

4. A fluid pressure operated jack mechanism comprising a vertically extending cylinder assembly, a piston assembly reciprocable vertically within said cylinder assembly, valve means for controlling the application of fluid pressure to said piston assembly, cam means carried by the upper portion of the piston assembly, a housing about the cam means and within which said cam means is vertically reciprocable, a pair of vertically spaced pivotally movable levers carried by said housing and actuable selectively by said cam means during piston travel in opposite directions, each of said levers including an outer section and an inner section movable relative to the outer section upon engagement by the cam means during its travel in one direction, means interconnecting said levers for simultaneous movement, and means for transmitting such movement to said valve means.

5. A fluid pressure operated jack mechanism comprising a vertically extending cylinder assembly, a piston assembly reciprocable vertically within said cylinder assembly, valve means for controlling the application of fluid pressure to said piston assembly, cam means carried by the upper portion of the piston assembly, a housing about the cam means and within which said cam means is vertically reciprocable, a pair of vertically spaced pivotally movable levers carried by said housing and actuable selectively by said cam means during piston travel in opposite directions, each of said levers including an outer section and an inner section pivotally movable relative to the outer section upon engagement by the cam means during its travel in one direction, a spring resisting said relative movement of the inner section of one lever, means interconnecting said levers for simultaneous movement, and means for transmitting such movement to said valve means.

SAMUEL V. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,696,044 Kuskin Dec. 18, 1928 2,276,358 Vickers Mar. 1'7, 1942 2,292,331 Vertson Aug. 4, 1942 2,347,302 Twyman et al Apr. 25, 1944 2,355,669 Moser Aug. 15, 1944 FOREIGN PATENTS Number Country Date 305,252 Germany Apr. 19, 1918 562,144 France Aug. 27, 1923

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