US3179059A

US3179059A - Pump

Info

Publication number: US3179059A
Application number: US220348A
Authority: US
Inventors: Robert J Browne; Heinz K Hetz
Original assignee: American Meter Co Inc
Current assignee: Elster American Meter Co LLC
Priority date: 1959-12-29
Filing date: 1962-08-06
Publication date: 1965-04-20
Anticipated expiration: 1982-04-20

Description

April 20,1965, R. J. BROWNE mm 3,179,059

PUMP

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April 0, 19 5 R. J. BRQWNE' ETAL 3,179,059

PUMP

2 Sheets-Sheet 2 Original Filed D99- 29, 1959 ited States Patent Ofifice 3,179,059 Patented Apr. 20, 1965 3,179,059 PUMP This invention is a variable stroke pump for feeding liquids at accurately controlled rates. In many uses the liquids are corrosive and may also have an appreciable solids content. The operating pressures may be high, i.e. hundreds or thousands of pounds per square inch. These and other factors impose severe operating requirements which are met by the present invention.

In the drawing, FIG. 1 is a longitudinal section of a pump, FIG. 2 is a top plan of the pump, and FIG. 3 is an exploded perspective of the pump cylinder.

The pump has a cylinder 1 with an inlet connection 2 on its under side at the outer end and an outlet connection 3 on its upper side toward the center. Between the inlet and outlet the cylinder is of stepped formation with the lower step 4 directly above the inlet and the upper step 5 between the inlet and outlet. In the step 4 is a vertical counter bore 6 concentric with the inlet 2 and terminating in a shoulder 7 around an inlet way 8. Slidably received in the bore 6 is a cup shaped valve seat member 9 having its bottom clamped against the shoulder 7. In the bottom wall of the seat member 9 is an inlet opening 10 surrounded by stepped seats 11 which cooperate with a ball check 12 in a manner described in greater detail in application Serial No. 843,695, now US. Patent No. 3,077,896. In the side walls of the seating member 9 are a plurality of angularly spaced openings 13, one or more of which register with an upwardly inclined passageway 14 in the outer end of the cylinder. During the suction stroke, the ball 12 is lifted off the seats 11 and liquid flows through the openings 10 and 13 into the outer end of the cylinder. During the pressure stroke, the ball engages the seats 11 preventing back flow. The upward sloping of the surface 14 in the direction of flow prevents build up of solids in the outer end of the cylinder. The solids tend to drain back toward the valve and to be entrained in the liquid flowing through the valve during the succeeding suction stroke. The arrangement also is self bleeding of air or other gases which may be liberated during the pumping process.

Seated on the rim 15 of the valve seating member 9 is a cap 16 clamped against the rim of the seating member by a valve cover 17 secured by cap screws 18 threaded into the cylinder. The valve cover 17 is of stepped shape complementary to the

steps

4 and 5 on the cylinder. An O-ring gasket 19 is arranged between the cap 16 and the rim of the seat member and a gasket 20 is arranged between the bottom of the seating member and the shoulder 7. These gaskets prevent metal to metal contact of similar metals which could result in galling. A coil spring 21 is arranged between the under side of the cap 16 and the ball 12 to supplement the force of gravity in obtaining the check valve action. The part of the cap 16 above the gasket 19 has a sliding fit in the bore 6 and the part of the cap below the gasket 19 has a sliding fit in the seat member. The part of the seat member between the

gaskets

19 and 20 has a sliding fit in the bore 6 and the part of the seat member below the gasket 29 has a sliding fit in the inlet 20. This construction permits high pressure operation and does not require a high degree of precision of manufacture.

In the step 5 is a bore 22 terminating in a shoulder 23 surrounding an outlet 24 from the cylinder. Slidably received in the bore 22 is a check valve of the same construction as at the inlet, corresponding parts being indicated by the same reference numerals with the subscript a. The discharge opening 13a register with an inclined way 25 which has the same kind of self cleaning and self bleeding action as the inclined way 14 at the inlet. During the suction stroke, the ball 12a closes against the seat 11a preventing back flow through the outlet 3. During the pressure stroke, the ball 12a is lifted off its seat and forced under pressure to the outlet.

The valves are easily serviced. When the valve cover 17 is removed, the

caps

16, 16a may be removed by screwing the cap screws 18 into threaded sockets 26, 26a. This exposes the valve seating members 9, 9a which may be readily lifted out by a hook inserted in any one of the openings 13, 13a. The servicing of the valves does not require the breaking of the plumbing connections to the inlet 2 or outlet 3.

At the inner end of the cylinder 1 is an integral tubular extension 27 received in a bore 28 in the pump body 29. The body 29 does not come into contact with the liquid being pumped and need not be made of corrosion resistant material. On the extension 27 are

annular grooves

30, 31 having tapered sides receiving conical ended set screws 32 (FIG. 2). In use, there is at all times a hydraulic pressure in the cylinder exerting a force tending to move the extension 27 out of the bore 28. This loads the conical ends of the set screws 32 in shear. This design positively locates the cylinder without requiring extreme accuracy in machining. The cylinder can be rotated on its axis to accommodate piping. If necessary, new holes may be drilled and tapped for the

fittings

37, 38. Within the extension 27 is an externally threaded packing nut 33 for packing 34, 35 on opposite sides of a lantern ring 36. Lubrication is supplied through a grease fitting 37 opposite the lantern ring 36. Excess pressure is prevented by a relief fitting 38. When the packing is to be flushed, the

lubricating fittings

37, 38 are removed and flushing piping is connected in place of the fittings.

The pump plunger 39 has a reduced portion 40 received in a bore 41 in a cross head 42 with a shoulder 43 on the piston abutting the end 44 of the cross head. In the reduced portion 40 of the plunger is a groove 45 receiving the conical ends 46 of set screws 47. It will be noted that the groove 45 is offset with respect to the set screws so that as the set screws are tightened, the conical ends engage tapered side 48 of the groove 45 and pull the shoulder 43 solidly against the end 44 of the cross head with sufiicient force to prevent stress reversal. The heavyipiston load during the pressure stroke is transmitted directly from the end 44 of the cross head to the shoulder 43 on the piston. During the suction stroke, the lighter force from the cross head to the plunger is transmitted through the conical ends of the set screws 47.

The opposite end of the cross head 42 is connected to a connecting rod 49 by a ball joint comprising a ball 50 fixed to the end of the connecting rod and ball socket members 51, 52 with the cross head. The socket member 51 which takes the pressure thrust, is larger than the socket member 52 and rests on a thrust washer 53. The socket member 52 is preloaded against the ball 50 by a spring washer 54 arranged between a washer 55 and a retaining ring 56. An O-ring seal 57 between the socket members 51 and 52 prevents leakage of lubricant. The ball joint connecting rod bearing is free to expand and contract with temperature changes and is self compensating for wear. The bearing is also self aligning and be cause it is located within the cross head, the thrust from the connecting rod transmits no moment to the cross .cross head into a hollow lubricant reservoir 63 where the grease is maintained under pressure by a spring 64 acting on a piston cup 65. As grease is forced into the reservoir,

the spring 64 is compressed until the piston cup moves past a vent opening 66, after which the grease flows out the vent opening indicating that the reservoir is full. The capacity ofthe reservoir in the cross headis sufi'icient so that lubrication is required only at infrequent intervals. Grease may be added through the fitting 58 while the pump is operating.

The connecting rod is driven by a crank shaft 67 having fixed thereto a crank 68 with a radial T-slot 69 slidably receiving the head 70 of a bolt 71. An adjusting screw 72 rotatably anchored in the crank by means of a set screw '73 and a groove 74 is threaded into the head 70 of the bolt and adjusts it along the T slot. The set screw 73, which is of the self looking or shake proof type, is adjusted into the groove 74 until the stroke adjusting screw 72 is free to rotate without any axial play or looseness. This arrangement simplifies manufacture and as sembly and insures accurate location of the stroke adjusting screw without precise machining. The position of the bolt in the T-slot is indicated by a pointer 75 on a plate or stroke indicator 76 fixed to conical washer 77 hearing on the outer surface of the T-slot. When the bolt is located. in the desired position in the T-slot, a nut 78 is tightened,'compressing the inner race '79 between the nut and the washer 77. At thesame time, the bolt head '70 is clamped solidly against the T-slot, thereby establishing a rigid connection between the bolt and the crank so that none of the driving load is taken by the adjusting screw. The connecting rod bearing is of the self aligning, anti-friction type arranged between the inner race 79 and the outer race 80 fixed in the connecting rod.

What is claimed as new is: I Y

1. In a reciprocating piston pump, a piston, a body having a bore concentric with and surrounding an intermediate portion of the length of the piston, a cylinder concentric with the piston and having at one end a tubular section received in said bore and carrying packing engaging the piston, said section having annular grooves each with a tapered shoulder facing the opposite end of the cylinder, and conical ended set screws in said body I engaging said shoulders, the pump pressure exerting a 2. In a reciprocating piston pump, a body with a pair of axially spaced concentric bores therein, a hollow cylindrical cross head slidable in one bore, a cylinder having a tubular projection fixed in the other bore, packing within said projection, a piston slidably extending through said packing with one end of the piston within the cylinder and the other end of the piston rigidly connected to the cross head, the connection between the cross head and piston comprising a shoulder on said other end of the piston abutting the cross head and a reduced cylindrical stem on the piston at the center of the shoulder extending into the cross head, said stern having an annular groove therein with a tapered side facing said shoulder, set screws in said cross head having conical ends offset away from said shoulder and engaging said tapered side of the groove and preloading the stem in tension to pull the shoulder solidly against said cross head for avoiding stress reversal in the stem, a connecting rod having a self aligning crank hearing at one end and having at the other end a ball and socket joint tothe cross head, said ball joint being located Within the cross head so that no forces are created tending to tilt the cross head and move the piston out of alignment with the packing.

3. In a reciprocating piston pump, a body with a pair of axially spaced concentric bores therein, a hollow cylindrical cross head slidable in one bore, a cylinder having a tubular projection fixed in the other bore, packing Within said projection, a piston slidably received in said packing with one end of the piston within the cylinder and the other end of the piston rigidly connected to the cross head, a connecting rod having a ball and socket joint con nection to the cross head whereby the connecting rod thrust does not tend to tilt the cross head and cause misalignment, a grease reservoir within the cross head between the ball joint and the end of theeross head remote from the connecting rod, a spring pressed plunger in said reservoir urging grease toward the ball joint, an external axially extending groove in the cross head, a grease fitting in the body opposite the groove and feeding grease to the groove, aport in the cross head leading from the groove to the reservoir between the ball joint and the plunger, and a grease relief .port uncovered as the plunger is forced back by the grease supplied through the fitting to fill the reservoir.

References Cited by the Examiner UNITED STATES PATENTS 1,679,425 8/28 Houston.

2,346,964 '4/ 44 Harper L. 103-38 X 2,503,907 4/50 Hefler 74- 44 2,555,809 6/51 Naab 74-44 X 2,733,664 2/56 Saalfrank 103-153 2,841,991 7/58 Saalfrank '7440 2,844,103 7/58 Bennett 103-453 2,863,471 12/58 Thurman 103-38 X LAURENCE V. BFNER, Primary Examiner. WARREN E. COLEMAN, Examiner,

Claims

1. IN A RECIPROCATING PISTON PUMP, A PISTON, A BODY HAVING A BORE CONCENTRIC WITH AND SURROUNDING AN INTERMEDIATE PORTION OF THE LENGTH OF THE PISTON, A CYLINDER CONCENTRIC WITH THE PISTON AND HAVING AT ONE END A TUBULAR SECTION RECEIVED IN SAID BORE AND CARRYING PACKING ENGAGEMENT THE PISTON, SAID SECTION HAVING ANNULAR GROOVES EACH WITH A TAPERED SHOULDER FACING THE OPPOSITE END OF THE CYLINDER, AND CONICAL ENDED SET SCREWS IN SAID BODY ENGAGING SAID SHOULDERS, THE PUMP PRESSURE EXTERTING A FORCE ON THE CYLINDER TENDING TO MOVE IT OUT OF SAID BORE AND HOLDING THE SHOULDER AGAINST THE CONICAL ENDS OF THE SET SCREWS, AND SAID CYLINDER BEING ANGULARLY ADJUSTABLE IN SAID BORE WHILE THE SET SCREWS ARE RECEIVED IN SAID GROOVES TO MAINTAIN THE AXIAL POSITIION OF THE CYLINDER IN THE BORE.