US2338707A - Valve latch device for pneumatic piston pumps, differential type - Google Patents

Description

Jan. 11, 1944. 2,338,707

VALVE LATCH DEVICE FOR PNEUMATIC PISTON PUMPS, DIFFERENTIAL TYPE A. BOYNTON Original Filed Jan. 31, 1939 2 Sheets-Sheet 2 Alexander Boyni'on Patented Jan. 11, 1944 VALVE LATCH DEVICE FOR PNEUMATIC PISTON PUMPS, DIFFERENTIAL TYPE Alexander Boynton, San Antonio, Tex.

Original application January 31, 1939, Serial No. 253,876. Divided and this application March 30, 1942, Serial No. 436,911

2 Claims.

This application is a division of my copending application Serial Number 253,876, filed January 31, 1939, and entitled Pneumatic piston pump, difierential type.

My invention relates to a means for lifting liquids from wells and of propelling liquids through pipe lines by the force of compressed air or gas acting under or behind a slug of liquid previously admitted into the eduction tube of a well or into a pipe line by the automatic action of valves which alternately admit a slug of liquid of predetermined weight and then admit under or behind the slug enough compressed air or gas to expel it from the well or pipe line.

The slugs of liquid are admitted into the eduction tube of a well or into a pipe line by means of a valve that controls the admission of liquid thereto (hereinafter referred to as the liquid intake valve) after a valve that controls the admission of air or gas thereto (hereinafter referred to as the air or gas valve) moves from one seat, referred to as the first seat, and closes upon another seat, referred to as the second seat. The air or gas valve and the liquid intake valve are urged to the only position in which they are both closed by a spring which may work in con- Junction with a latch; the latching means tending to hold the air or gas valve and the liquid intake valve closed in the first position, and tending to hold the air or gas valve closed in the second position while the liquid intake valve is open. The force of the air or gas is utilized to hold the air or gas valve seated upon the second seat while the slug of liquid to be expelled is entering the eduction tube or pipe line through the liquid intake valve. The weight or back pressure of the slug of liquid thus admitted into the eduction tube or pipe line is utilized to unseat the air or gas valve from its second seat, and to hold the air or gas valve open intermediate its two seats, while, in that position, the liquid intake valve cuts off the admission of more liquid until the slug has been expelled; whereupon the air or gas valve again assumes the closed position upon its second seat with the liquid intake valve open. This cycle is autoinvention has particular relation to certain novel ieatures of construction, operation, and arrangement of parts which manifestly can be changed and combined in different ways within the scope and purpose of this invention.

Other objects and advantages of this invention will be apparent from the following description as illustrated in the accompanying drawings in which:

Fig. 1 is a vertical section of a well equipped with this device.

Fig. 2 is a vertical section of the preferred form of the device.

Fig. 3 is an enlarged vertical section of one embodiment of the latching means in one of its positions.

Fig. 4 is a view similar to Fig. 3 showing the latching means in its other position.

Fig. 5 is a cross-section on the line 55 of Fig. 3.

Fig. 6 is a detail elevation of the ball roof member.

Fig. 7 is a vertical section of a modified form of the invention.

Identical characters are employed to designate and refer to corresponding parts throughout the drawings.

Fig. 1 shows a well equipped with this device in which the .outerjcasing I is-sealed above the ground surface G by the casing head 2 having two openings,,one of which is closed by the bull plug 3, the other being connected with the pipe line 4 for the purpose of conveying away gas produced by the well. The pressure tubing 5 is suspended centrally within the casing l and proximate its upper end rests upon the plate 6 to which it may be welded or otherwise joined in leak proof contact therewith. The cap I is then screwed down upon the lead ring 9, at the same time compressing the lead ring 8, to form a seal against the escape of formation gas from the well. Any other casing head arrangement that will afford a seal between the well casing and the pressure tubing may be used; many such casing heads being well known to the art.

The pressure tubing 5 extends above the casing head 2 and is connected by means of the coupling ID with the T H, having a lateral branch I la connected to the air or gas pipe line l2. The

upper end of said T is formed to support the The pressure tubing is connected at its lower end to the swaged coupling it which has the tapered seat I60, to be engaged by the lead seal i1, secured upon the eduction tubing proximate the lower end thereof. The lower end of the swaged coupling 16 is connected to the tubular housing l8, which is connected at its lower end to the coupling I9.

Within the housing 18 is the seal valve 26, held resiliently upon the upper end of the seal valve spring 26 to normally engage the seal valve seat it?) at the lower end of the swagedcoupling it. Said spring 2| rests upon the annular plate 22 in the coupling l9. Below the coupling IS the tubing may be extended downwardly as far as is desired.

While the pressure tubing 5 is being lowered into the well, the seal valve contacts the seal valve seat Ifib upon which it is held by force of the spring 2|, plus the fluid pressure in the well. When the eduction tubing I3 is lowered into the position shown in Fig. l, the slotted extension 2% forces the seal valve down to the position shown in Fig. 1, whereupon well liquid is freed to enter the device. This action of the seal valve 'rfiwhich keeps well liquid out of the pressure tubme while the eduction tubing is being lowered or withdrawn is very important, in that high flow starting pressures are thereby avoided; as is explained in my prior Patent 2,104,008.

Compressed air or gas is supplied into the pressure tubing from an outside source through the pipe line 12 if the well does not produce enough gas to flow it, as was illustrated in my prior Patents 2,042,583 and 2,104,008-

The lead seal l1 forms the barrier which confines compressed air or gas within the annular space between the pressure tubing 5 and the eduction tubing I3. The nipple also contains the pressed in liquid intake governor 48, further held in place by the pressed in check valve seat 'i upon which the check valve 45 normally engages, as clearly appears in Fig. 2. The lower case nipple 3713, the air or gas intake connection member 21, the uppercase nipple 31A, the connection and valve sleeve member 36, and the eduction tubing connection 35, all threadedly joined together as shown in Fig. 2, constitute the outer shell of the device which is threadedly joined to the eduction tubing I3. I

The airor gas intake connection member 27, serves as a connection between the lower half of the device containing the liquid intake governor, check valve, and latch assembly and the upper half of the device containing the three valves and related parts. It will be noted that the air or gas may enter the device from the pressure tubing through the ports 21a and that the well-liquid may also enter through the separate longitudinal passages 21b.

The air or gas valve first or lowerseat member 59 furnishes the first or lower seat for this valve as shown at 59a. The air or gas valve 28 is threadedly connected to the latch shaft 40, as shown in Fig. 2, The air or gas valve shank 23c fits within the central longitudinal bore through the liquid intake slide valve 30. This valve is looked over said shank and upon the shoulder 28?) of the air or gas valve member by the threaded engagement between the shank 28c and 31a, as appears in Fig. 2.

. A metallic ring 32 forms the upper support for the yieldable ring 33, the lower support for this ring being a conforming recess in the upper end of the connection andvalve sleeve. member.

The valve 31 has a close working fit within the rings 32 and 33. working fit within the central bore through the sleeve member 25 and the opening through the valve housing member 23 above the air or gas valve second or upper seat 29a. The valve 28 has the clearance 29b around it for the purpose of allowing the passage of suiflcient compressed air or gas from the pressure tubing into the eduction tubing to expel the liquid slugs, as will be described later.

It is desirable that a latching means be emplcyed to cause snap action of the valves. A latch similar in construction and operation to the one here shown appears in my prior Patents Nos. 1,968,633; 2,006,999; 2,0id135; 2,042,583; 2,054,- 924; and 2,104,008.

The latch housing nipple 38 is threadedly connected to the lower boss 21 of the connection member 2'? and is closed at its lower end by the chamber plug 15, the latch sleeve 44 being pressed in as appears in Fig. 2. The upper end of the latchspring 39 engages a recess in the boss 21f and the lower end rests in a depressed annular shoulder formed upon the upper end of the ball roof 4!, which engages the latch balls 43 upon the ball floor d2, locked in place upon the shaft 40 by the nut 58. It will be noted that the surfaces engaging the latch balls are inclined, so as to force the balls outward to engage the sleeve Mi by whatever force may be imparted by the spring 39, always installed under some compression. It will be noted further that the length of the sleeve 44 is such as will allow the latch balls to roll slightly over its top end on theup stroke and to roll slightly under on the down stroke of the valves.

The forcewhich the latch employs at either extreme of the valve travel is determined by the expansive force of the spring 35 and by the magnitude of the horizontal movement over either end of the sleeve 34, as well as by the length of theradius describing the arcs forming the ends of this sleeve. The longitudinal openings'd la provide for free circulation of a lubricant that should be placed within the nipple 38 to facilitate smooth Working of the latch. Slight clearance at 27d is provided between the latch shaft 30 and the central longitudinal bore in the conneotionmember 27 to keep foreign substances out of the latch and to provide that the latch mechanism will not become impinged upon fluid on the down stroke of the valves or tend to create a partial vacuum on the up stroke. The portion of reduced diameter 10a provides that the clearance between these members is many times greater, except at the beginning and at the completion of each stroke. The normal position of the shaft being as shown in Fig. 2, it is apparent that a lubricant of proper viscosity in the. latch chamber will not leak. out while the device is in transit or in storage during the interval between manufacture and installation.

The check valve ie prevents compressed air or gas from migrating out of the device intouthe lower regions of the well where such air or gas The slide valve 30 has a close 7 remain closed until compressed air or gas is turned into the pressure tubing via the pipe line I2 and the pressure entering beneath the valve 28 via the ports 21a and the annular passage 21d is built up high enough to spring the latch and drive the valve 28 from its first or lower seat 59a. to its second or upper seat 29a.

It is presumed that the latch is adjusted to hold the valve 28 upon its first seat with enough force to compress the spring 38 the full distance of the valve travel when the latch releases. The valve 28 then will remain seated upon its second or upper seat 28a until enough well liquid enters the eduction tubing to exert sufiicient back pressure upon the top of the valve 28to unseat it, with the aid of the expansive force of the spring 39. When the air or gas valve 28 is engaged upon its second seat 29a, the latch, being in the position shown in Fig. 4, should hold with enough force to produce sufiicient recession of the valves to close the valve 30 by forcing the lower end of it down past the inclined opening 36d when the latch releases.

It should be noted here that more downward movement is required to close the valve 3| than will be required to close the valve 30. When the liquid intake valve 38 and the leakproof valve 3! are wide open, that is when the air or gas valve 28 is upon its upper or second seat, well liquid enters the eduction tubing via the perforations 24a, through the spring 2|, between the fins 280., by the valve 28, through the slots 26b and the liquid intake governor slots 480., by the check valve 46, through the longitudinal passages 21b, the opening 36d, through the openings 38b of the slide Valve 30, and by the valve 3 I.

It will be noted that all valves move in unison, that the air or gas valve 28 is closed in both positions of extreme travel, and that a slight recession of the valves from their extreme upper positions opens the air or gas valve 28, closes the liquid intake valve 38, and leaves the valve 3| still Open. The extreme upper position of the lower ends of the valves 30 and 3| are shown at D and F, respectively. The level to which these valves recede in order to close the liquid intake is indicated at E and J, respectively, The clearance 291) between the valve 28 and its chamber is sufiicient to allow enough compressed air or gas to pass through this clearance to fiow the well whenever the valve 28 is positioned intermediate of its seats 59a and 28a. Each time a slug of well liquid enters the eduction tubing and is expelled as stated, the air or gas valve 28 seals off upon the seat 29a; thus again opening the liquid intake and repeating the operation as long as well liquid and compressed air or gas are supplied to the device.

The relation of the three valves and the function of each will be stated now. The valve 28 controls the admission of compressed air or gas from the pressure tubing 5 to the eduction tubing l3. On its first seat 59a this valve constitutes a barrier against the well liquid (if any should leak past the valve 38) entering the pressure tubing while the well is standing between operating intervals. In this connection it is proper to observe that many oil wells of small production are flowed at intervals, sometimes several hours or even days apart. 7

During these intervals it is important that no well liquid be allowed to enter the pressure tubing because this would increase the air or gas pressure required to initiate the flow. On its second seat 290, the valv .28 prevents .the com.-

pressed air or gas in the pressure tubing from aerating the liquid slug while the same is entering the eduction tubing. The valve 28 is the first of the three valves to open on the up stroke and the last to close on the down stroke.

The slide valve 38, which controls the admission of well fluid to the eduction tubing, is closed (covers the opening 38d) when the air or gas valve 28 is engaged upon its first seat 59a, as appears in Figs. 2 and 7. This valve 38 is open, the lower end being at the level D when the valve 28 is closed upon the seat 29a. The slide valve 30 again closes at slight downward movement of the valve 28 away from its seat 28a, this closure taking place at the level E. With relation to the other two valves 28 and 3|, the valve 30 is the last to open on the up stroke and the first to close on the down stroke. The oflice of the leak proof valve 3| is to prevent well liquids that may leak past the valve 30 from entering the eduction tubing while the device is not being operated. In the closed position shown in Fig. 2, fluid leaking past the valve 30 enters the transverse ports 36a, the annular space 361), and the open space 360 to contact the outer surface of the yieldable ring 33; thereby to cause the inner surface of this ring to seal tightly against the valve 3 I. Obviously the greater such pressure the tighter will be the seal produced thereby. On the up stroke of the valves, this valve is the second to open, the first to open being the valve 28. On the down stroke the valve 3| is'second to close, the first to close being the liquid intake valve 30, and the last to close being the air or gas valve 28, then contacting the seat 59a.

From the foregoing it may be stated concisely that on the up stroke, the valves open in the following order: 28-3l-30, and that they close on the down stroke in the order of 38-3l-28.

The difference between the weight of the slug and the air or gas pressure used to expel it equals, and is determined by, the force required to compress the spring 39 far enough to allow the valve 28 to contact the seat'29a, plu whatever force the latch employs in the uppermost position of the valves. The weight of the slug, therefore, may be increased by increasing the air or gas pressure, and vice versa. Increasing the air or gas pressure decreases the percentage of difier- 'ence between the air or gas pressure and the weight of the slug, and vice versa, While the actual difference between them remains constant.

The device and all modifications thereof shown in this application may be installed in all the ways shown in my hereinbefore mentioned patents.

Fig. 7 shows a modified form of the invention shown in Fig. 2, and which may be installed within the bracketed space A, Fig. 1, in the same manner and operated in the same way as was de scribed for the device shown in Fig. 2. I

It will be noted that the latch assembly in Fig. 7 is difierent in construction and position from the one shown in Fig. 2. The eduction tubing connection A houses the pressed in metallic ring 32, the yieldable ring 33, and its lower extension is internally threaded to engage the metallic ring 34, which holds the yieldable ring 33 in position, as shown in Fig. 7. Fluid pressure is transmitted to the outer surface of the yieldable ring 33 through the annular space 351) and the transverse ports 35a, in order to cause the liquid intake leak proof v ve3IA t be. e ppedinmai streamment by the yieldable ring 33, if fluid under pressure should leak past the valve 35, as was explained for the very similar valve 3| in Fig. 2.

The latch shaft 40A, locked in position by the nut 51, contacting the lower internal boss 279, supports the plate 52, to which it is soldered or welded at 5212. This plate is in turn soldered or Welded into the lower end of the latch assembly nipple at 52a, which nipple it hermetically closes. The upper end of this nipple is closed by the plug 50. The latch spring 39 fits into a circular recess in the lower end of the plug 50. The latter spring, under some compression against another circular recess in the upper end of the ball roof 4!, urges the latch balls 43 downward against the ball floor 42A, which is threadedly secured upon the lower end of the latch carrier shaft 49 and is locked in place by the solder 42a.

The latch balls are urged outwardly by the beveled surfaces of the ball roof and the ball floor to contact the pressed in latch sleeve 44 over the convexly curved ends of which sleeve the latch balls rolls at each end of the valve'travel. The latch shaft 49A may be adjusted upward or downward by means of the enlar ed threaded lower end, the adjustment being secured by the lock nut 51. Adjusting the shaft 49A upward, moves the latch sleeve 44 higher, causing the latch balls to engage more upon the lower end and less upon the upper end thereof as the latch operates. Adjusting the latch shaft downward produces the opposite effect upon the latch, as is apparent in Fig. '7.

The threaded connection between the latch carrier shaft 49 and the lower enlarged end Me of the valve SlA provides the connection between said valves and the latch, the reduced portion 3 lb being to enable the valve 3IA to open at proper travel on the up stroke of the valves. It will be observed that the enlargement 3 He is also threadedly connected to the housing nipple 38, which has an easy working fit over the nipple 5|, the lower end of the nipple 38 being threadedly connected to the guide plug 53, into which plug is threaded the valve sleeve 54, locked by the nut 55.

It will be noted that the air or gas valve 28A is threaded upon the lower end of the sleeve 54, spaced apart from the slide valve 35 by the space: nipple 56. The valve 36, which has a close Working fit within the central bore through the connection and valve sleeve member 36A and has a similar fit within the central bore through the upper end of the housing member 29, has a central openin which provides a close fit over the lower end of the sleeve 54, the upper end of the valve 32! being supported by the shoulder 54a. The central bore through the valve 28A and through the sleeve 54 providing an easy working fit over the shaft 46A, and the nipple 38 being free to move over the latch nipple 5|, the three valves assembly is as free to operate. aswas described for the action of the deviceshown in Fig. 2.

The latch assembly nipple 5 I may be filled with a lubricant to lubricate the latch. It will be noted that the'lower portion of the shaft 49 is of reduced diameter, the reduction being slightly below the top of the plug 59. This is provided so that the latch will breathe while operating. On the up stroke of the valves, slight movement elevates the lower end of the enlarged portion of the shaft 49 above the plug 5?), the reduced section having large clearance in the central bore through the plug 55, fluid will rush into the latch chamber to compensate for the outgoing movement of the shaft 49. On the down stroke of the valves, this opening through the plug 55 is not restricted by entrance of the enlarged upper portion of the shaft 49 until near the end of the stroke, the slight displacement resulting from the remainder of the down stroke being allowed to escape through the small clearance which should be provided between the enlarged portion of the shaft 49 and the bore through the plug 55.

This arrangement for accommodating the displacement within the latch housing while the device is in operation, also provides against leaking of the lubricant out of the latch chamber during transportation and handling of the device between the point of manufacture and the well in which it is to be installed, the breather spac being so slight that a lubricant or proper viscosity will not leak out even though the device be allowed to stand upside down. The longitudinal openings 44a likewise facilitate the free movement of the latch by providing that the lubricating fluid may circulate around the latch sleeve 44 when the latch acts, as in Fig. 2.

It will be observed also that the air or intak connection member 21A provides the entrance ports Elafor the air or gas and the longitudinal passages- 21b for the well liquid.

An important difference between the constructions of these devices is that in Fig. 2 the latch shaft ii) and all valves are joined togetherand move in unison, without being fastened. to any other member; whereas in Fig. '7 the latch shaft 45A is threadedly connected within th intake connection member 21A.

Another structural difference is that the latch assembly depends below the connection 2? in Fig. 2; whereas in Fig. 7 this assembly is upstanding above the connection meniber 21A. Of some further importance in making sure that no foreign substance will foul the latch assembly, is the fact that the latch assembly nipple 5! in Fig. 7 is itself completely housed within the latch housing nipple 38.

It is obvious that mechanical changes may be made in the structure, and that equivalents may be substituted for the parts shown; and I reserve the right to make such mechanical changes, substitutions, and adaptations within the scope of the invention as comprehended by the appended claims.

I claim:

1. A latch device for yieldably holding a valve system in either one of two limit positions of longitudinal movement, said latch device com prising: a stem; a ball floor member secured on said stem; a ball roof member mounted on said stem to slide toward or from said floor member; a compression spring on said stem adapted to press said roof member toward said floor memher for all positions of said stem; a latch sleeve; means for holding said sleeve in a fixed position around said stem and members; one or more balls adapted to be forced by said floor and roof members against said sleeve and t engage one of the ends of the sleeve for determining either of said valv positions; a .fixed abutment for the opposite end of said spring, whereby the spring performs the dual function of forcing said balls into engagement with the latch sleeve and moving the valve system in one direction.

2. A latch device for yieldably holding a valve system in either one of two limit positions of longitudinal movement, said latch device comprising: a stempa bail floor member secured on said stem; a ball roof member mounted on said stem to slide toward or from said floor member; a spring adapted to press said roof member toward said floor member at all positions of said stem; a latch sleeve mounted around said stem and members; one or more balls adapted to be iorced by said floor and roof members against said sleeve and to engage one of the ends of the sleeve for either of said valve positions; means for holding said sleeve in adjustabl longitudil0 nal position relative to said stem to vary the relative latching efiect of the balls on the ends of the sleeve for the two limit positions of the valve system; a relatively fixed abutment for the opposite end of said spring, whereby the spring performs the dual function of forcing said balls into engagement with the latch sleeve and moving the valve system in one direction.

ALEXANDER BOYNTON.

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