US2471860A - Reciprocating pump - Google Patents

Description

May 31, 1949. N. E. BRIGHAM 2,471,860

RECIPROCATING PUMP Filed April 22, 1944 7 Sheets-Sheet 1 1 A/EAW/J E 5174M; VVENTOR.

ATTORNEY SEARCH ROUM 7 Sheets-Sheet 2 Filed April 22, 1944 9 65 Ma J22 Z 0 Z Z .5

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REC IPROCATING PUMP Filed April 22, 1944 7 Sheets-Sheet 4 6 35 8 5 ?6 /4 6,4 //A V ///W 7////////% ATTORNEY SLAKUH KUUN May 31, 1949. N. E. BRIGHAM 2,471,860

RECIPROCATING PUMP Filed April 22, 1944 7 Sheets-Sheet 5 VENTOR ATTORNEY 1949- N. E. BR'IGHAM 2,471,860

RECIPROCATING PUMP Filed April 22, 1944 7 Sheets-Sheet 6 I I z 1.13. J

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May 31, 1949. N. E. BRIGHAM RECIPROCATING PUMP 7 Sheets-Sheet 7 Filed April 22, 1944 [Ve/szm EYE/"147mm VENTOR ATTORNEY Patented May 31, 1949 SEARCH RUUM RECIPROCATIN G PUMP Nelson E. Brigham, Arlington, N. J., assignor to Worthington Pump and Machinery Corporation, Harrison, N. J a corporation of Delaware Application April 22, 1944, Serial No. 532,271

22 Claims. 1

This invention relates to reciprocating pumps, and more particularly to a variable capacity, constant speed pump.

An object of the present invention is to provide a constant speed pump employing reciprocating fluid displacement means operated by a novel rotary crank means, and in which the capacity of the pump may be varied from zero to full capacity as a function of variation in the throw of the crank means, with consequent variation in the stroke of the fluid displacement means.

Another object is to provide a pump of the variable capacity, constant speed type wherein reciprocating displacement plungers are employed for pumping the fluid, in which novel crank means are operatively connected with the respective plungers for converting rotary motion of the crank means into reciprocatory motion of the plungers, and in which novel means are provided for varying the throw of the respective crank means to vary the stroke of the plungers, with consequent change in the capacity of the pump while the latter is operating at constant speed.

Another object is to provide a pump of the variable capacity, constant speed type employing reciprocating displacement plungers for pumping the fluid, in which eccentrics are adjustably carried by a common driver and connected with the respective plungers for imparting pumping motion thereto, and in which a single control means is employed for simultaneously shifting the eccentrics in like amounts relatively to the axis of the common driver to vary the throw of the eccentrics, with consequent change in the stroke of the displacement plungers.

A further object is the provision of a rotative driver having an eccentric adjustably carried thereby, and in which novel means are employed for adjusting the eccentric relatively to the axis of rotation of the driver to vary the throw of the eccentric.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing a reciprocating pump of a preferred form embodying the invention, and the features forming the invention will be specifically pointed out in the claims.

In the drawings:

Figure 1 is a vertical and partial sectional view of a pump in accordance with the present invention, with the pressure fluid and lubricating circuits removed for the sake of clearness.

Figure 2 is an enlarged sectional view of a control cylinder and its piston.

Figure 3 is a transverse sectional view of the pump structure of Figure 1.

Figure 4 is a partial sectional view of a side rod.

Figure 5 is a sectional view taken along the line 55 of Figure 7, but at a reduced scale.

Figure 6 is a sectional view taken along the line 6-6 of Figure 7, and also at a reduced scale.

Figure '7 is an enlarged sectional view taken substantially along the line 'l-I of Figure 13.

Figure 8 is a longitudinal sectional view of a pilot valve.

Figure 9 is a transverse sectional view of a valve bushing in which the pilot valve of Figure 8 operates.

Figure 10 is a side view of a portion of the-pump frame, a control cylinder and a pressure fluid circuit.

Figure 11 is a fragmentary elevational view of a control bar.

Figure 12 is a face view of an eccentric cross bar.

Figure 13 is an end view of the structure of Figure 10.

Figure 14 is an elevational view of a rotative driver or eccentric shaft, with a portion thereof shown in section.

Figures 15, 16, and 17 are sectional views of crank means or eccentric structures showing the relative positions thereof in a given position of the eccentric shaft of Figure 14.

Figure 18 is a sectional view of the eccentric structure of Figure 15, but illustrating the eccentric structure in its full throw position in contradistinction to the zero throw position of Figure 15.

Figure 19 is a sectional view taken along the line l9-l9 of Figure 14, but with certain parts removed for the sake of clearness.

Figure 20 is a view taken substantially along the line 20-20 of Figure 1.

Referring more particularly to the drawings, Figures 1 and 3 illustrate a pump frame I upon which is mounted a cylinder block 2 and made secure by bolts 3. The cylinder block 2 is provided with a plurality of cylinders or plunger chambers 4 arranged in a straight line and spaced longitudinally of the cylinder block 2 when viewed according to Figure 1. Three plunger chambers are embodied in the cylinder block of Figure 1, but any desired number of plunger chambers may be employed, depending upon the specific work for which the pump is designed. All the plunger chambers are arranged vertically, and each chamber is provided with a reciprocating work element or displacement plunger 5 which extends some distance above the cylinder block. Each displacement plunger 5 has its upper end bolted at 6 to an upper crosshead l, the reciprocation of which imparts reciprocatory motion to the plunger. The respective displacement plungers 5 are individually driven, but in a predetermined and unvarying timed order.

Two side rod assemblies 8 are associated with each upper crosshead l. The side rod assemblies 8 parallel their respective vertically positioned displacement plugers 5, and each side rod comprises a work rod 9 which is bolted at In to one end of its associated upper crosshead All the side rod assemblies 8 are of like construction. and each rod 9 is enclosed in telescopically related tubes II and I2. In Figure 4, the tube H is secured to a collar l3 which is clamped to the upper crosshead 1 through tightening of the nut l0. External threads M are provided on the tube I2 for the reception of a nut l5 which is threaded into engagement with a plate-like body I6, the latter being clamped to the upper end of the cylinder block 2 through tightening of the nuts IE on the respective tubes l2. The tubes |2 are threaded into bores I! in the cylinder block 2, as at l8, the bores I! being of such diameter-s as to freely accommodate their respective work rods 9. All the work rods 9 extend downwardly to positions inside the frame I, and the work rods are arranged in parallel relationship, one with the other and with the displacement plungers 5.

Each pair of rod-s 9 is attached to a crosshead IS. The crossheads l9 are contained in the frame I and are guided for reciprocation by crosshead guides formed integrally with the frame. Crank means or eccentric devices 2| are operatively connected with the respective crossheads IQ for imparting reciprocatory motion to the crossheads and similar motion to the displacement plungers 5 through the medium of the work rods 9. While the crossheads l9 are individually driven by their respective crank means 2|, the crossheads l9 maintain a predetermined operating order devoid of any phase change to maintain the unvarying operating order of the displacement plungers. All the crank means 2| are mounted on an eccentric shaft or driving shaft 22 which is supported in bearings 23, the latter being in turn supported by the frame I.

In Figures 1 and 2, the chambers 4 have communication with cross passages 24, each cross passage having communication with a suction passage 25 and a discharge passage 26. All the suction passages 25 have communication with a common inlet chamber 21, while the discharge passages 25 have communication with a common discharge chamber 28. A threaded opening 29 is provided in the cylinder block 2 for connection with a suitable fluid'inlet pipe (not shown) to supply fluid to be pumped to the inlet chamber 21, and a threaded opening 3|] is also provided in the cylinder block 2 for connection with a suitable fluid discharge pipe (not shown) for receiving pumped fluid from the discharge chamber 28.

Valve seats 3| are contained in the respective suction passages 25, and similar valve seats 32 are contained in the respective discharge passages 26. Figure 3 shows a suction Wing valve 33 operatively associated with one of the seats 3|,

which valve is yieldingly biased to a closed posi tion by a compression spring 34 abutting that valve and a plug 35 threaded into a bore 36 in the cylinder block 2. Thus the cross passages 24 are isolated one from the other so far as operation of the respective displacement plungers 5 is concerned, even though all the passages 25 have communication with the one inlet chamber 21. Similar discharge wing valves 37 are operatively associated with the respective seats 32, which valves are yieldingly biased to a closed position by compression springs 38. The springs 38 are interposed between the valves 3'! and plugs 39 threaded into bores 40 in the cylinder block 2. The cross passages 24 are also isolated one from the other on the discharge side of the pump so far as the operation of the displacementplungers 5 is concerned.

When viewing Figure 3, an upward stroke of the plunger 5 causes the valve 3| to move off its seat to permit fluid from the inlet chamber 2'! to flow into the chamber 24. Upon downward movement of the plunger 5, the valve 3! is caused to lift off its seat 32 to permit the fluid in the cross passage 24 to flow into the discharge chamber 28.

Accordingly, the suction valves 33 prevent reverse flow of fluid from the cross passages 24 back to the inlet chamber 27 on the down strokes of the respective displacement plungers 5. In the same manner, the valves 37 prevent reverse flow of the fluid from the discharge chamber 28 back to the cross passages 24 on the up stroke of the respective displacement plungers 5.

The eccentric shaft 22 is of hollow formation and is provided with three bodies 4| spaced longitudinally of the shaft. Each body 4| comprises a part of one of the crank means 2|, and all the crank means 2| are of like construction. In Figure 3, the body 4| comprises an integral part of the eccentric shaft 22, and the body is eccentrically located with respect to the axis of the shaft, which is best illustrated in Figure 14. The body 4| in Figure 3 serves as a mount for an eccentric disc 42, which is adjustable on the body to vary the crank throw, and which is connected with an eccentric strap 43 forming a part of a connecting rod 44. This connecting rod is drivingly connected with one of the crossheads l9 by a crosshead pin 45, so that when the eccentric disc 42 is positioned eccentrically with respect to the driving shaft 22 reciprocatory motion will be imparted to the crosshead. The eccentric disc 42 in Figure 3 is so positioned that it is co-axial with the driving shaft 22, at which time no motion is imparted to the crosshead l9 even though the driving shaft 22 is rotating at normal speed.

Figures 15, 16, and 1'7 show the relative positions of the crank means 2| in a given position of the driving shaft 22, with the bodies 4| spaced apart radially of the eccentric shaft. Each eccentric disc includes an opening 46 for accommodating its respective body 4 and the openings 46 are defined by two opposed flat faces 41 and 48 and two opposed faces 49 curved concentrically of the axis of the eccentric disc 42. Each body 4| is provided with a flat face 50 which lies in face to face engagement with the face 41 of its associated eccentric disc 42. A second fiat face 5| is also provided on each body 4|, the faces 5| lying in parallelism with the faces 50 on the respective bodies. Thus all the faces 41, 48, 50, and 5| are parallel one with the other. Curved end faces 52 are also provided on the bodies 4|, and

SEARCH ROOM the eccentric discs 42 lie in the planes of their respective bodies 4|.

In Figures 5, l6, and 7, the crank means 2| are adjusted to their zero throw positions, at which time the axes of all the eccentric discs 42 are co-axial with the eccentric shaft 22. Figure 18 illustrates one of the eccentric discs 42 adjusted to its maximum throw position. Means for adjusting the eccentric discs 42 to desired crank throw positions for controlling the stroke of the displacement plungers 5 include eccentric crossbars 53 which lie in face to face engagement with the respective flat faces 48 in the eccentric discs 42. A rib 54 is formed on each eccentric cross bar 53 for engagement inside a correspondingly shaped groove 55 in its associated eccentric disc 42. While the eccentric discs 42 may be shifted relatively to and laterally of the eccentric shaft 22, the eccentric cross bars 53 are restrained from relative movement with respect to their associated eccentric discs.

Flanges 55 are provided on the bodies 4|, and the eccentric cross bars 53 lie between the flanges 55 and upon the flat faces 5| on the bodies 4|. The flanges 55 are arranged at right angles to the axis of the eccentric shaft 22. Thus the eccentric discs 42 may be shifted for crank throw changing purposes by adjusting the eccentric cross bars 53 to different positions at right angles to the axis of the eccentric shaft 22, since the eccentric cross bars are keyed to their respective eccentric discs 42. With the eccentric discs 42 in the positions of Figures 15, 16, and 17, one face 49 of each eccentric disc lies in engagement with one end face 52 on its associated body 4|, and when the eccentric discs 42 are adjusted to their maximum throw positions, the other face 49 lies in engagement with the second end face 52. Thus the faces 49 and 52 constitute stops which precisely position the eccentric discs 42 in their zero and maximum crank throw positions.

All the eccentric discs 42 are shifted simultaneously and in like amounts to change the stroke of the displacement plungers 5. Means for adjusting the eccentric cross bars 53 to shift the eccentric discs 42 comprise a control shaft or rod 51 which is axially slidably in and guided by the eccentric shaft 22. This control rod is recessed at 58 for the reception of racks 59, which racks lie inside the eccentric shaft 22 in parallelism with the axis of the control rod 51, and at right angles to their respective eccentric cross bars 53. The teeth 50 on the racks 59 are in meshing engagement with teeth 5| on their associated eccentric cross bars 53. Figures 14 and 19 illustrate the bodies 4| as being provided with openings 52 for exposing the racks 59, thereby permitting engagement between the teeth 50 and 5|. Efiective engagement between the two sets of teeth 50 and 5| is made possible by locating the flat faces 5| such with respect to the axis of the driving or eccentric shaft 22 as to intersect a considerable amount of the inside surface of the driving or eccentric shaft. The teeth 60 angle axially with respect to the axis of the control rod 51, the latter being co-axial with the driving or eccentric shaft 22. An angle of approximately 26 has been found satisfactory, although it is to be understood that the invention is not limited to this angle of the teeth and that any degree of angle found practical may be employed, this angle being best illustrated in Figures 11 and 14. The teeth 5| on the eccentric cros bars 53 are correspondingly angled, as shown in Figure 12.

The racks 59 are fixedly secured to the control rod 51, as by bolts 53 in Figure 1. The racks II are made detachable from the control rod 51 to facilitate replacement in case of excesssive wear on the rack teeth, the same being true of the eccentric cross bars 53 with respect to their associated eccentric discs 42.

Adjustment of the control bar 51 relatively to and axially of the eccentric shaft 22 imparts corresponding movement to the racks 59. In view of the angle of the teeth 50 and 5|, movement of the racks 59 relatively to the eccentric cross bars 53 imparts movement to the eccentric cross bars and the eccentric discs 42, but at right angles to the axis of the eccentric shaft 22. While the eccentric discs 42 are shiftable relatively to the bodies 4|, the engaging flat faces 41 and 50 and the eccentric cross bars 53, which are interposed between bodies 4| and the eccentric discs, key or look the eccentric discs to the shaft 22 for rotation therewith. At the same time the control rod 51 is keyed to the eccentric shaft 22 for rotation therewith, since engagement between the racks 59 and the control rod 51 and the eccentric cross bars 53 prevent relative rotation between the control rod and the eccentric shaft 22, but permit free relative axial movement. The faces 41 and 50 in one crank means 2| are spaced radially from the same faces in an adjacent crank means, and determine the direction of relative radial adjustment of the eccentric discs 42. This 20 spacing is the desirable arrangement in a threecylinder pump, but other degrees of spacing will work equally well in connection with pumps embodying a different number of cylinders.

While the eccentric cross bars 53 are free to shift laterally of the eccentric shaft 22, the eccentric cross bars are restrained from relative movement longitudinally of the eccentric shaft 22 by the flanges 56. Figure 1 illustrates the eccentric discs 42 and the bodies 4| as being of the same size longitudinally of the eccentric shaft 22. Side plates 54 are bolted at 55 to the ends of the eccentric discs 42, which side plates engage the flanges 55, the eccentric discs 42, and the eccentric straps 43 to hold the eccentric straps and the eccentric discs in assembled relationship with their respective bodies 4|. The side plates 64 are recessed at 55, see Figure 20, which facilitates assembly of the side plates, in addition to permitting radial movement of the side plates relatively to the eccentric shaft 22.

In Figure 1, a compression spring 51 is housed in the eccentric shaft 22 and abuts one end of the control rod 51. The other end of the spring 51 abuts a plug 58 threaded into the end of the eccentric shaft 22, this end of the shaft 22 extending to a position exteriorally of the frame I for connection with a suitable drive (not shown).

An increased pumping stroke is attained by shifting the control bar 51 against the tension of the spring 51. Means for shifting the control bar 51 to increase the pumping stroke comprises a control mechanism 59, see Figures 1, 2, and 7. In Figure 2, the control rod 51 extends into a control cylinder 10 and is provided with a piston 1| which is slidably contained in the control cylinder. In view of the fact that the control rod 51 rotates as a unit with the driven eccentric shaft 22, suitable bearings 12 are interposed between the piston 1| and the control rod to eliminate rotation of the piston relatively to the control cylinder 10. Increased stroke is obtained by admitting a pressure fluid to the chamber 13 in the control cylinder 10. The pressure of the fluid acts on the piston 1| to impart axial movement to the control rod against the tension of the spring 81. Decreased stroke is obtained by releasing pressure fluid from the chamber I3, thereby permitting the control rod 51 to be shifted in a. reverse direction through the influence of the spring 67.

The pressure fluid may comprise oil such as is employed for lubricating the working parts of the pump as a whole, which permits the pressure and lubricating circuits to be connected with a single oil circulating pump. Oil under pressure is admitted to the chamber I3 through a pipe I4, see Figures 2, l0, and 13. Admission of fluid under pressure to the pipe I4 is controlled by a pilot valve I5, see Figure 7. The pilot valve is located between the pipe I4 and a supply pipe I6, see Figures and 13, which communicates with a gear pump indicated generally at T1. Such pumps are old and well known in the art and need not be described in detail. that Figure 1 illustrates a gear I8 as being attached to the eccentric shaft 22 and meshing with a gear I9 which drives the pump 11. In Figures 6 and 7, the cylinder I0 extends partly inside a control box I9 which houses the pilot valve I5. A valve bushing 80 is made secure in a bore 8| in a body 82 comprising a portion of the control box "I9. The pilot valve I5 is slidably guided in the valve bushing 80, and communication between the pipes I4 and I8 is controlled by the position of the pilot valve I5 inside the valve bushing 80.

The pilot valve I5 is arranged vertically in the control box 19 and is guided at its upper end by a bushing 83 made secure in a. bore 84' in the control box I9. That portion of the pilot valve I5 operating in the valve bushing 80 is shaped to provide heads 84 and 85 slidably engaging the inner face of the valve bushing 80, the two heads being separated by a neck 86 of such diameter as to provide an annular space 8'! between the neck and the valve bushing 80. In Figure 7, the discharge end of the pipe I8 communicates with a passage 81 in the control box I9, which passage has communication with openings 88 in the valve bushing 80. With the pilot positioned as shown in Figure '7, the head 84 is so positioned as to close the openings 88, thereby preventing fluid under pressure from entering the valve bushing.

The openings 88 comprise three in number, and the valve bushing 80 is additionally provided with three openings 89 and three openings 90. The openings 90 are positioned above the upper face 9I of the body 82, while the openings 89 are located between the two sets of openings 88 and 9|. All the openings are of like contour and arrangement. Figure 9 illustrates the valve bushing 80 in cross-section in the plane of the openings 88. A groove 92 extends circumferentially of the valve bushing 80 and in its outer face in the plane of the openings 88, and a similar groove is provided in the valve bushing 80 in the plane of the group of openings 89. Downward movement of the pilot valve 15 in the valve bushing 80 establishes communication between passage 81' in the control box 19 and the annular passage 81 inside the valve bushing. The openings 90 remain closed. At this time, fluid under pressure enters the annular passage 81 and flows outwardly therefrom through a passage 93, see Figure 6, in the body 82. A passage 94 places the passage 93 in communication with the pipe I4, so that pressure fluid will be admitted to the chamher I3 of the control cylinder I0 as long as the head 84 of the pilot valve 15 permits pressure fluid to flow through the openings 88.

The grooves 92 assure free passage of the pressure fluid at all times, and eliminate the necessity of precise positioning of the valve bushing to align one each of the openings 88 and 89 with the passages 81 and 93, respectively. Admission of pressure fluid into the chamber I3 imparts an axial shift to the control rod 51 for increasing the throw of the crank means 2I, thus correspondingly increasing the stroke of the displacement plungers 5, the amount of crank throw increase depending upon the amount of pressure fluid admitted to the chamber I3. To decrease the throw of the crank means 2I, or to bring the crank means back to their zero throw positions, pressure fluid is bled from the chamber I3. This is accomplished by lifting the pilot valve I5 in the valve bushing 80 suificiently far to bring the head I5 to an uncovering position with respect to the openings 90. At this time, the spring 81 returns the control rod 5! to or toward the position of Figures 1 and 7, which causes the pressure fluid to reverse its flow in the pipe 14, enter the annular passage 81 and overflow into the control box I9 by way of openings 90.

Means for actuating the pilot valve I5 comprise a floating lever 95, see Figure 7, one end of which is loosely positioned in an opening 96 in the pilot valve I5. This end of the floating lever is connected with the pilot valve by a pivot 91, which causes axial movement to be imparted to the pilot valve through pivotal movement of the floating lever. The other end of the floating lever 95 is loosely connected with a link 98, as by a pivot 99, the link 98 being connected with an arm I00, as by a pivot IOI. This arm is keyed to a shaft I02 which is rotatably supported in bores I03 in bodies I04 and I05 formed integrally with the control box I9, see Figure 5. To the shaft I02 is keyed a control lever I08, which lever extends downwardly and is provided with a ball bearing supported roller I01 at its lower end. This roller lies in a circumferential groove I08 in the control rod 51, the roller being confined between the side faces I09 of the groove I08. Thus axial movement of the control rod 51 imparts pivotal movement to the lever I06, such pivotal movement imparting pivotal movement to the arm I00 and the floating lever 95.

To the floating lever 95 is connected a link I ID, as by a pivot I I2 located at the center of the floating lever. This link is attached to a micromotion or control member III which is actuated by a positioning motor, indicated generally at I I2 in Figures 1, 10 and 13. Motors of this type are provided with pilot control switches, indicated generally at I I3 in Figure 1, which will meet any stroke requirement of the control member III. Various types of controls are available to suit the particular type of service for which the pump may be used. Obviously, the present pump may be operated manually.

,The throw of the crank means 2I may be increased in desired amounts by moving the control number III downwardly a predetermined distance, as when viewing Figure 7, which pivots the floating lever 95 counterclockwise about the pivot 99 as a fulcrum. counterclockwise movement of the floating lever 95 moves the pilot valve I5 downwardly from its neutral or zero throw position of Figure 7, which uncovers the open- 9 ings 88. As the head 34 of the pilot valve I5 uncovers the openings 88, pressure fluid flows into the annular space Bl, through the openings 89, the passages 93 and 94 of Figure 6, the pipe I4, and into the chamber I3 of the control cylinder I0.

Admission of pressure fluid to the chamber I3 causes the control rod 51 to move axially and shift the racks 59 relatively to the eccentric cross bars 53. with consequent lateral movement of the eccentric discs 42 relatively to the axis of rotation of the eccentric shaft 22, and in crank throw increasing directions. At the same time, such axial movement of the control rod 51 swings the control lever I06 counterclockwise to the dotted line position of Figure 7, as an example, and turns the arm I in the same direction, which pivots the floating lever 95 clockwise about the pivot II2 as a fulcrum. Clockwise rotation of the floating lever 95 lifts the pilot valve I relatively to the valve bushing Bil-and brings the head 84 back to its neutral position, which cuts off the supply of pressure fluid to the control cylinder and prevents further axial movement of the control rod 51.

Return of the pilot valve I5 to its neutral position through clockwise rotation of the floating lever, as upon termination of a crank throw increasing movement of the control rod 51, traps the pressure fluid in the chamber I3 of the control cylinder Ill, so that the crank throw will be maintained against the tension of the spring 61 until the pressure fluid is released from the control cylinder. The pressure fluid in the control cylinder is released by lifting the pilot valve I5 from the position of Figure '7, and such release is attained by lifting the control member III 4eeL8iLabout the pivot 99 as a fulcrum, thereby lifting the pivot 91 and the attached pilot valve 15. Upward movement of the pilot valve I5 shifts the head 85 of the pilot valve to uncover the openings 90, but the openings 88 remain closed because of the head 84.

When the openings 9|] are uncovered, movement of the control rod 51 by the spring 6'! advances the piston 'II and forces the pressure fluid from the control cylinder, the pressure fluid overflowing into the control box 19 by way of the openings 90. Return movement of the control rod 51 swings the control lever I06 in a clockwise direction, which pivots the floating lever 95 in a counter-clockwise direction about the pivot I I2 as a fulcrum, thereby bringing the pilot valve I5 back to its normal position of Figure 7. Return movement of the control rod 51 decreases the crank throw in accordance with the extent of return movement of the control rod.

The actual increase in crank throw is determined by the distance the pivot H2 is moved downwardly from its neutral full line position of Figure 7, which in turn determines the actual stroke of the displacement plungers 5. The pivot II2 remains fixed, except when its position is changed through adjustment of the control member III; and any downward movement of the pivot II2 pivots the floating lever 95 counterclockwise about the pivot 99 as a fulcrum. Any downward movement of the pilot valve as an incident to counter-clockwise pivotal movement of the floating lever 95 uncovers the openings 88 to deliver pressure fluid to the control cylinder I0. Since the floating lever 85 is also influenced y movement of the control rod 51, clockwise rotation of the floating lever about to elevate'the pivot I I2, which pivots the floating,

the pivot II2 as a fulcrum brings the pilot valve I5 back to its neutral position when the floating lever 95 has moved in a clockwise direction to the extent of its previous counter-clockwise movement. Accordingly, pivotal. movement of the floating lever 95 in one direction as an incident to shifting of the pivot I I 2 sets the control lever I06 in motion through movement of the control bar 51 for pivoting the floating lever in the reverse direction and to the same extent. Such movement of the pilot valve 15, first in one direction and then in the other, or by a succession of movements in one direction, provides a control valve means which effectively regulates the flow of pressure fluid into and out of the control cylinder for crank throw adjusting purposes.

With the pilot valve I5 in the neutral position of Figure '7,the upper end ofthe head 84 barely covers the openings 88, and the lower end of the head 85 barely covers the openings 90. Thus the openings 88Start to open immediatelyupon downward movement of the pilot valve, and the openings 98 start to open immediately upon upward movement of the pilot valve. To assure free movement of the pilot valve I5, even through pressure fluid should accumulate in the bore 8| beneath the pilot valve or above the pilot valve in the bushing 83, a passage II4 passes longitudinally through the valve, which passage communicates with the opening 96 to provide an escape for the pressure fluid which might otherwise interfere with the eflicient operation of the pilot valve. Pressure fluid overflowing into the control box I9 has access to the frame I.

In Figures 10 and. 13, a suction oil pipe I I5 leads from the frame I to the oil pump 11. The oil pressure pipe I6 is connected with a pipe I I5 which leads directly to the discharge side of the pump 11. The pipe H6 is branched at Ill and distributed on opposite sides of the frame I for supplying lubricant to the crosshead guides 28. Thus the pressure fluid circuit is tapped into the lubricating circuit of the pump, so that the pump 'I'I provides the oil circulating medium for both circuits.

Referring to Figures 1 and 3, the displacement plungers 5 pass through packing II8 which is confined between plunger throat bushings H9 and plunger glands I20 in the bores 4. Plungers glandrings I2I are interposed between the plunger glands I20 and the packing H8. The plunger glands I20 are threaded throu h the plate-like body I6, which permits the packing to be placed under the necessary degree of compression.

The control cylinder I0 is bolted at I22 to'an end cover member I23, and the latter is bolted at I 24 to the frame I. Hand hole cover plates I25 are bolted at I26 to the sides of the frame I, and the control box I9 is also provided with a hand hole cover plate I21, which is bolted at I28 to the control box.

While the present pump is ideally suitable for marine service, which requires a constant speed power pump in which the pump capacity may be varied from zero to maximum to meet boiler feed water requirements, the pump is equally suitable for other pumping duties. The operation of the adjustable crank means is smooth throughout their entire crank throw range, and ample lubrication is assured for all parts of the crank means. The side plates 64 are positioned according to Figure 20, and their inner faces are recessed at I29. so that the side plates function as scoops which fill the spaces in the crank means with lubricating oil.

Any foregoing statements regarding directional movements of the respective parts of the control mechanism 69 define the construction and operation of those parts in accordance with the specific arrangement of the structure as shown in the drawings. Accordingly, such statements are not limitations, since all these parts, as well as other parts of the pump, may be arranged differently, so that the directional movements would be different.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. In a variable capacity pump, a cylinder, a reciprocating pumping plunger operating in said cylinder, a rotative driver, adjustable crank means carried by said driver and operatively connected with said plunger, a control rod operatively connected with said adjustable crank for varying its throw to change the stroke of said plunger, a pressure fluid circuit including a control cylinder, a piston on said control rod and operating in said cylinder, valve means for controllin the admission of pressure fluid into said control cylinder for moving said piston and the control rod, and means actuated by movement of said control rod for closing said valve upon admission of a predetermined amount of pressure fluid to said cylinder.

2. In a variable capacity pump, a cylinder, a reciprocating pump plunger in said cylinder, a rotative driver, crank means adjustably mounted on said driver and operatively connected with said plunger, a control rod operatively connected with said crank means for adjusting the crank means to vary its throw and change the stroke of said plunger, a pressure fluid circuit including a control cylinder, a piston on said control rod and operating in said control cylinder, valve means for controlling the admission of pressure fluid into said control cylinder for moving said piston and the control rod, and means actuated by movement of said control rod in predetermined increments for closing said valve to arrest movement of said control rod.

3. In a variable capacity pump, a cylinder, a reciprocating pumping plunger in said cylinder, a rotative driver, adjustable crank means carried by said driver and operatively connected with said plunger, a control rod operatively connected with said adjustable crank means for varying its throw to change the stroke of said plunger upon movement of the control rod, a pressure fluid circuit including control cylinder, a piston on said control rod and operating in said control cylinder, a valve for controlling the admission of ressure fluid into said control cylinder for moving the control rod, a control member, an operating connection between said control member and said valve for opening the valve to admit predetermined quantities of pressure. fluid into said control cylinder, and means actuated by movement of said control rod for closing said valve upon admission of a predetermined amount of pressure fluid to said cylinder.

4. In a variable capacity pump, a plurality of cylinders, reciprocating pumping plungers in said cylinders, a drive shaft, eccentrics adjustably mounted on said drive shaft and operatively connected with the respective plungers, a control rod operatively connected with the eccentrics for varying their throws to change the strokes of the respective plungers upon movement of the control rod, a pressure fluid circuit including a control cylinder, said control rod having a piston operating in said cylinder and controlled in its position by the admission of pressure fluid to the cylinder or the release of pressure fluid therefrom, a valve for controlling the admission of pressure fluid into said cylinder or for releasing the pressure fluid therefrom, a positioning motor actuated means, an operating connection between said positioning motor actuated means and said valve for opening the latter to admit pressure fluid to said control cylinder, and means operatively connecting said operating connection with said control rod for closing said valve upon the admission of a predetermined amount of pressure fluid to said control cylinder.

5. In a variable capacity pump, a cylinder, a reciprocating pumping plunger in said cylinder, a drive shaft, an eccentric adjustably mounted on said drive shaft and operatively connected with said plunger, a control rod operatively connected with said eccentric for adjusting the latter relatively to said drive shaft through movement of the control rod, a pressure fluid circuit including a cylinder, 3, piston on said control rod operating in said control cylinder for moving the control rod through admission of pressure fluid to the control cylinder or the release of pressure fluid therefrom, a valve for controlling the admission of pressure fluid into said control cylinder or releasing the pressure fluid therefrom, a positioning motor, a positioning member controlled by said positioning motor, an operating connection between said positioning member and said valve for opening the latter to admit pressure fluid to said control cylinder, said operating connection being responsive to movement of said control rod for closing said valve upon admission of a predetermined quantity of pressure fluid to said pressure cylinder or for opening the valve upon predetermined movement of said positioning member, said control rod rotating with said drive shaft, and bearing means interposed between said control rod and said piston for rotatably relating the control rod to the pison.

6. In a variable capacity pump embodying a reciprocating pumping plunger, the combination of a drive shaft, an adjustable eccentric operatively connected with said plunger and having an opening therein through which said drive shaft is extended, coacting faces on said eccentric disc and said drive shaft for guiding the eccentric disc for movement transversely of the drive shaft for varying the throw of the eccentric to change the reciprocating stroke of said plunger, co-acting means on said eccentric disc and said drive shaft for limiting movement of the eccentric disc in one direction beyond its zero throw position and in another direction beyond its maximum throw position, and co-acting means on said control rod and said eccentric disc for shifting the eccentric disc through longitudinal movement of said control rod.

'7. In a variable capacity pump having a plurality of reciprocating pumping plungers, the combination of a drive shaft, adjustable eccentric discs each operatively connected with one of the pioneers and having opening therein through which said drive shaft is extended, said eccentric disc and the drive shaft having faces co-acting to guide the eccentric discs for movement transversely of the axis of rotation of the drive shaft to vary the throw of the eccentrics, a control rod guided for longitudinal movement by said drive shaft, and co-acting rack teeth on said control rod and the eccentric discs for shifting the latter through longitudinal movement of said control rod.

8. In a variable capacity pump having a plurality of reciprocating pumping plungers, the combination of a drive shaft, adjustable eccentric discs each operatively connected with one of the plungers and having openings through which said drive shaft is extended, said eccentric discs and the drive shaft having faces co-acting to guide the eccentric dics for movement transversely of the axis of rotation of the drive shaft to vary the throw of the eccentrics, a control rod guided for longitudinal movement by said drive shaft, co-acting rack teeth on said control rod and the eccentric discs for shifting the latter through longitudinal movement of said control rod, and co-acting stop faces on said drive shaft and the eccentric discs for limiting movement of the latter in one direction beyond their zero throw positions and in another direction beyond their maximum throw position.

9. In a variable capacity pump embodying a reciprocating plunger, the combination of a hollow drive shaft having an opening intermediate its ends, an adjustable eccentric disc operatively connected with said plunger and having an opening through which said drive shaft is extended, means on said drive shaft for guiding said eccentric disc for movement radially of the axis of rotation of the drive shaft, a control rod movably guided in said drive shaft, and means on said control rod arranged angularly with respect to the axis of the drive shaft and co-acting with said eccentric disc through said opening for shifting the eccentric d sc through longitudinal movement of the control rod for varying the throw of the eccentric.

10. In a variable capacity pump embodying a reciprocat ng pumpin plun er, the combination of a tubular drive shaft having an opening in its perimeter, an adjustable eccentr c disc oneratively connected with said plunger, means on said drive shaft for guid n said eccentric d sc for moveme t radiallv of the axis of rotation of sa d drive shaft. an eccentric cro s bar attached to said eccentric d sc, a control rod movablv guided in said drive shaft, a rack fixed to said control rod, and formations on said eccentric cross bar and the rack engaging through said opening and angularly arranged so as to shift the eccentric disc radially of the axis of rotation of the drive shaft through longitudinal movement of said control rod, said rack and said eccentric cross bar keying the eccentric disc to the drive shaft for rotation therewith.

11. In a variable capacity pump, a cylinder, a reciprocating pumping plunger in said cylinder, a tubular drive shaft an eccentric adjustably mounted on said drive shaft and operativel connected with said plunger, a control rod slidably guided inside said drive shaft in co-axial relationship therewith, co-acting means on said control rod and said eccentric for shifting the eccentric to different throw positions through relative movement of the drive shaft and the control rod, said co-acting means keying the control rod to the drive shaft for rotation therewith, a pressure fluid circuit including a control cylinder, a piston connected with the control rod and operating in said control cylinder, said control rod being rotatably related to said piston, a

pilot valve interposed in said fluid circuit for controlling the flow of pressure fluid to and from the control cylinder, a spring acting on said control rod to yieldingly hold the control rod in a neutral position and with the eccentric in a zero throw position, a floating lever connected with the pilot valve and having an operating connection with said control rod, and a positioning means connected with said floating lever for controlling the admission of pressure fluid to the control cylinder for moving the control rod against the tension of said spring or for releasing pressure fluid from the control cylinder, said operatng connection being actuated through longitudinal movement of the control rod for adjusting the pilot valve to a closed position upon admission of a predetermined quantity of pressure fluid to the control cylinder.

12. In a variable capacity pump, a plurality of cylinders, reciprocating pumping plungers in said cylinders, variable throw crank means each operatively connected with one of said plungers, an adjusting means connected with said crank means to vary the throw thereof, a fluid pressure circuit, pressure fluid responsive means for operating said adjusting means, a valve interposed in said pressure fluid circuit for controlling the application of pressure fluid to said pressure fluid responsive means, and positioning means including a floating lever connected with said valve and said adjusting means for actuating the valve.

13. In a variable capacity pump, a plurality of cylinders, reciprocating pumping plungers in said cylinders, a tubular drive shaft having eccentric bodies fixed thereto and provided with openings in the planes of the eccentric bodies, eccentric discs each slidably mounted on one of said bodies for movement transversely of the drive shaft, eccentric straps each connected with one eccentric disc and one plunger, 9. control rod slidable longitudinally inside said drive shaft, angular means on said control rod and connected with the eccentric discs through said openings for shifting the eccentric discs relative to the eccentric bodies through movement of the control rod for varying the throw of the eccentric discs, and means for operating said control rod inpredetermined increments.

14. In a variable capacity pump, a plurality of cylinders, reciprocating pumping plungers in said cylinders, a tubular drive shaft having eccentric bodies fixed thereto and provided with openings in the planes of the eccentric bodies, eccentric discs each slidably mounted on one of said bodies for movement transversely of the drive shaft, eccentric straps each connected with one eccentric disc and one plunger, a control rod slidable longitudinally inside said drive shaft, angular means on said control rod and connected with the eccentric discs through said openings for shifting :he eccentric discs relative to the semen-- tric bodies through movement of the control rod for varying the throw of the eccentric discs. means for operating said control rod in predetermined increments, and plates attached to said eccentric discs and engaging the eccentric straps and said eccentric bodies to restrain the eccentric straps and said eccentric discs from relative movement longitudinally of said drive shaft.

15. In a variable capacity pump, a plurality of parallel cylinders, reciprocating plungers in said cylinders, an operating cross head connected to each of said plungers, operating eccentric straps connected to said cross heads, eccentrics mounted in said eccentric straps, a driving shaft, said eccentrics adjustably carried by said driving shaft, and means shiftable longitudinally of said driving shaft to adjust the positions of the eccentrics relative to the driving shaft to vary the stroke of said cross heads for varying the throw of said plungers.

16. A variable capacity pump as claimed in claim 15 including pressure actuated means for shifting said longitudinally shiftable means, and pressure responsive means-for controlling operation of said pressure actuated means.

17. A variable capacity pump as claimed in claim 15 including a pressure fluid circuit embodying a control cylinder, a piston connected to said longitudinally shiftable means and operating in said control cylinder, valve means for controlling the admission of pressure fluid into said control cylinder for moving said piston to move said longitudinally movable means, and means actuated by movement of said longitudinally movable means for closing said valve upon admission of a predetermined quantity of pressure fluid into said cylinder.

18. In a variable capacity pump, a plurality of parallel cylinders, reciprocating plungers in said cylinders, an operating cross head connected to each of said plungers, operating eccentric straps connected to said cross heads, eccentrics mounted in said eccentric straps, a driving shaft, crank bodies formed on said driving shaft, toothed cross bars carried by said eccentrics, toothed racks adjustably carried by said shaft and having their teeth meshing with the teeth of said cross bars, and means for shifting said toothed racks longitudinally of the axis of said driving shaft for individually adjusting said eccentrics to vary the stroke of said cross heads for varying the throw of said plungers.

19. A variable capacity pump as claimed in claim 18 wherein said driving shaft is hollow and is provided with radial openings through which said racks project, and a control rod extending longitudinally through said shaft and connected to said racks for shifting them.

20. A variable capacity pump as claimed in claim 18 wherein the teeth on said racks and the teeth on said cross bars extend at an acute angle to a plane perpendicular to the axis of said driving shaft.

, 21. In a variable capacity pump, a plurality of parallel cylinders, reciprocating plungers in said cylinders, an operating cross head connected to each of said plungers, operating eccentric straps connected to said cross heads, eccentrics mounted in said eccentric straps, a driving shaft, crank bodies formed on said driving shaft, toothed cross bars carried by said eccentrics, toothed racks adjustably carried by said shaft and having their teeth meshing with the teeth of said cross bars. and means for shifting said toothed racks longitudinally of the axis of said driving shaft for individually adjusting said eccentrics to vary the stroke of said cross heads for varying the throw of said plungers, said driving shaft being hollow and provided with radial openings through which said racks project, and a control rod extending longitudinally through said shaft and connected to said racks for shifting them, pressure actuated means for shifting said control rod, and pressure responsive means for controlling operation of said pressure actuated means.

22. A variable capacity pump as claimed in claim 18 including a pressure fluid circuit embodying a control cylinder, a piston connected to said toothed rack shifting means and mounted in said control cylinder for reciprocation therein, the position of said piston in said control cylinder being controlled by admission of pressure fluid to the cylinder or the release of pressure fluid from the cylinder, a valve for controlling the admission of pressure fluid into said cylinder or for releasing the pressure fluid therefrom, a positioning motor, means actuated by said positioning motor, an operating connection between said positioning motor actuated means and said valve for opening the valve to admit pressure fluid into said control cylinder, and means operatively connecting said operating connection with said toothed rack shifting means for closing said valve upon the admission of a predetermined quantity of pressure fluid into said control cylinder.

NELSON E. BRIGHAM.

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

UNITED STATES PATENTS Number Name Date 1,317,877 Manly et al. May 4, 1915 1,149,728 Cialo Aug. 10, 1915 1,283,249 Manly Oct. 29, 1918 1,630,168 Caut May 24, 1927 1,874,010 Hess Aug. 30, 1932 1,989,117 Svenson Jan. 29, 1935 2,048,524 Svenson July 21, 1936 2,115,121 Phillips Apr. 26, 1938 2,241,378 Evans May 13, 1941 2,247,922 Potter July 1, 1941 2,312,157 Galbreath et a1. Feb. 23, 1943 2,319,485 Alaburne May 18, 1943 FOREIGN PATENTS Number Country Date 366,097 Italy 1938

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