US2834298A - Manually operable piston pump - Google Patents

Description

May 13, 1958 G. w. WRIGHT ET A1. 2,334,298

MANUALLY OPERABLE PIsToN PUMP Filed May l5, 1952 I 2 Sheets-Shea?. l

3 lfd-f ffy-@b l IIIIIIIII May 13, 1958 G. w. WRIGHT ETAL MANUALLY OPERABLE PIsToN PUMP 2 Sheets-Sheet 2 Filed May 15, 1952 United States Patent 2,834,298 MANUALLY oPERAnLE PIsroN PUMP George W. Wright and Otto R. Scheurer, Fort Wayne,

Ind., assignors'to Tokheim Oil Tank and Pump Conipany, Fort Wayne, Ind., a corporation of Indiana Application May 15, 1952, Serial No. 287,878 12 Claims. (Cl. 103-175) This invention relates to a piston pump and especially to a manually operated, double acting piston pump for volatile and corrosive liquids.

It is an object of the invention to produce a high capacity piston pump for manual operation, which will have a high displacement. ratio to give a high suction lift and will be especially suited for pumping volatile liquids such as gasoline and airplane fuels, which will be of light weight, compact, and of `small physical size relative to its high capacity, which will be resistant to corrosion by the liquids lbeing pumped so that it will be adapted not only for pumping the somewhat corrosive gasoline fuels but also for pumping corrosive chemical liquids, which will provide such corrosion resistance with a minimum use of expensive corrosion resistant metals, which will operate with low friction loss to permit easy and eilcient manual operation, and which will operate over a wide temperature range, especially at extremely low temperatures. It is an object of the invention to provide a pump which fulfills the foregoing objects and which is of simple construction and is inexpensive to manufacture in quantity production. It is a `special object of the invention to provide such a pump which can be readily manufactured from die castings and sheet-metal stampings.

In a double acting pump embodying the invention, the pump housing is desirably made as an assembly of three light weight die-castings, of -a metal such as aluminum, magnesium, or alloys thereof, joined at two spaced parallel separation planes. The -central body forms a pump cylinder and inlet and outlet passages opening through its end faces and with side Walls shaped to permit die withdrawal. The two end or cover members contain ICC larger than the cylinder, to overlap the ends of its walls, and are desirably seated in and Sub-assembled to the covers, substantially co-planar with the separation faces of the covers. Each valve plate is sealed to the central bearing boss of its `associated cover and to the dividing wall or webs ybetween the intake and discharge passages, and such passages are thus sealed from each other and from the interior of the bearing bosses.

Desirably, the longitudinally-extending portion of the joined inlet passages is widened to provide a ilat screen chamber, and its side and end walls are formed to support an interfitting flat screen. A removable plate in one of the covers permits removal and replacement of the screen.

To provide corrosion resistance, the wear-receiving parts are made of corrosion resistant metal, such as stainless steel. Such wear-receiving parts comprise essentially the valves tand valve plates, the piston rod and its bearings, and a cylinder liner, and these parts-are of small physical size so that a minimum of lcorrosion resistant metal is required, and are of simple form and construction. Other interior surfaces of thev pump, comprising the inner surfaces of the die-cast housing parts, may be made edectively corrosion resistant by applying a corrosion-resistant coating to them.

The accompanying drawings illustrate the invention. In such drawings, Fig. 1 is a rear elevation of an assembled pump embodying the invention; Fig. 2 is a longitudinal section, taken on line 2 2 of Fig. l; Fig.- 3 is a transverse central section, taken on line 3--3 of Fig. 2; Fig. 4 is a section of ia modified piston; Fig. 5 is an elevation of the inner face of the front cover member; Fig.

6 is an elevation of a valve plate, showing the valves and the special sealing member; and Fig. 7 is an enlarged partial section showing the valve plate (without valves) `assembled to the cover shown in Fig. 5 land against the body of the pump; Fig. 8 is a fragmental side central bosses to support bearings for the reciprocating piston rod, and form inletand outlet-passage chambers on opposite sides of such central bosses, separated by webs or walls extending generally radially from the bosses. Such chambers are open through the separation face of the cover and are defined byA side walls shaped to allow free die withdrawal. Each chamber includes an inner or central portion positioned to overlie the cylinder `and an outer portion in open communication with the inner portion and positioned to overlie and communicate with one of the passages in the body. A iiat sheet-metal valve plate seated between the body and each cover-'closes the end of the cylinder and forms a wall for the open interface side of the central portions of the chambers in the cover, but leaves the outer portions of the cover chambers uncovered for communication with the body passages. In the assembled pump, the cover chambers form portions of inlet and outlet passages defined in part by the valve plates and which lie outside the valve plates opposite the ends of the cylinder, and such passages extend to `and are joined to and by the communicating passages in the body. Intake and discharge connections may be made to the joined passages at any point, preferably in the body portions of such passages.

Thevalve plates are desirably circular and somewhat elevation of the special sealing member; and Fig. 9 is a fragmental section of a preferred form of screen.

The housing of the pump shown in the `drawings is composed of three main parts, a main body 10, a front cover 30 and a rear cover 50, each formed as a `die casting of light weight metal. The body 10 has mounting pads 11 at oppositesides, and the pump is adapted to be mounted by either of such pads 11 or by its intake -and discharge pipes 12 and 13 upon any suitable support and in any desired position and at any .desired angle. For convenient reference, it is assumed in this description that the pump is mounted in the upright position shown in Figs. l and 2. f

The 'body 10 has iiat parallel end faces and flanges 20 at its ends for attachment of the covers, and each flange desirably carries a pair of locating pins 21. A central cylindrical wall 14 extends continuously between the end faces to form the cylinder of the pump. At the bottom of the body there is a reinforced portion forming an intake tting 15 formed and tapped for the reception of the intake pipe 12. Above this, and -below the cylindrical wall 14 there is a wide and flat screen chamber 16 extending from face to face through the body parallel with the cylinder and providing communicationfrom the intake fitting 15 to the inlet passages of the cover members described below. The opposite side walls of the screen chamber 16 contain inwardly -opening wedge shaped grooves 17 which cooperate with similar grooves in the covers to form a seat for a flat screen, and the cylinder wall carries a pair of ribs to support the'mid portion of the screen.

At the top, the body 14 is formedto provide an outlet fitting 18 internally threaded for the reception of the discharge pipe 13. Immediately below this fitting 18 and above the cylindrical wall 14 an outlet passage 19 extends Patented May 13, 1958- 3 from face to face through the body, providing communication from the outlet passages of the covers to the discharge pipe 13. A X- The body is readily adapted to be made as a die casting, for the walls of the cylinder 14 and of the two passages 16 and 19 are all straight and generally normal 'to' an end face, without undereuts, and may be made with a slight taper for draft to permit die withdrawal. When made as a die casting, the body requires little machining, the main requirements being to dress the cylinder to true cylindrical shape, and to drill and tap bolt holes.

The cylinder is tted with a thin liner 22 which may be rolled from flat stock and pressed in place. Desirably, it is of 'substantially the same length as the body 1), so that its ends lie flush with the end faces of the body.

The front cover has a peripheral flange 31 to mate with the body ilange 20, and at its sides has end-wall portions 32 extending inwardly in a planeofset below the face of the flange 31. Between such wall portions 32 there is a vertical enlargement which forms an inlet chamber 33 at the bottom and an outlet chamber V34 at the top, each with a central portion opposite the end of the cylinder and an outer portion positioned for alignment with one of the body passages 16 and 19. outer Yportion of the lower chamber 33 is of the same wide and flat configuration as the body opening 19, to form thefront portion 26 of the screen chamber and its walls contain similar grooves 17 to support a screen therein. A central bearing boss 35 protrudes inwardly from the outer wall of the vertical enlargement, and this is joined by walls or webs 36 extending radially and slightly upward to the side walls of the enlargement and across the end-wall portions 32 to the llange 31. The boss and webs together form a transverse wall separating the chambers 33 and 34.

The boss 35 contains a pressed-in bearing 41, and that boss, together with an outward extension thereof, forms a closed-end sleeve providing a blind hole for the re- Vception of the front end 70 of the piston rod. To permit the closed-end sleeve to breathe during the reciprocation of the piston rod therein, breather passages 42 are formed in the side walls of the boss, outside the bearing 41.

The edges of the walls 36 are provided with side ridges 37 forming a groove 38 between them for the reception of thespecial sealing member. The top edges of the ridges 37 are continuous and co-planar with shoulders 39 at the outer edges of the end wall portions 32, and such ridges and shoulders form a valve-plate seat bounded by the inner edge of the ange 31. Desirably, the supporting seat 37-39 lies below the surrounding ange face a distance equal to the thickness of the plate 40 to position the exposed face of the plate 40 co-planar with the face of the ange 31. On one side of one Wall 36 and on the opposite side of the other wall 36, the cover carries bosses 43 for the reception of screws to hold the plate 40 in sub-assembly with the cover 30 and to clamp the sealing member between them.

The rear cover is similar to the front cover 3] and of the same general configuration, forming a valve-plate seat like that of theV front cover, and providing inlet and outlet chambers 33 and 34 separated by a central boss and walls 36. The boss 55 has a central opening to pass `the piston rod 68, and at its inner end closely surrounds the piston rod 68 and forms a shoulder 56 to support a packing gland 57. A bearing 51 lies on the opposite side of the packing 57 and is pressed inward against the packing by a retainer 52. The lower part of the rear cover 50 forms the rear portion 58 of the screen chamber and the end wall thereof is formed with an opening covered by a removable plate 59 to permit insertion and removal of the screen. The outer wall of the rear cover 50 carries two alternate supports 62 for a pair of fulcrum links 64 for the operating handle 66.y

The two covers are readily adapted to be formed vas die castings. The use of the valve-plate permits their The - 4 inlet and outlet chambers to be made as cavities which are all freely open to the faces of the covers. The cover side-walls contain no undercuts and may be tapered to provide draft for die removal.

A screen is mounted in the grooves 17 of the screen chamber 16-26-58. A fine-mesh screen is usually desired, and may be made of two layers, with an upper reinforcing layer and an underlying screen layer. The edges of the screen are bent back upon themselves, for example an underlying fine mesh screen may have its edges bent back over the edges of the overlying reinforcing layer, to form a wedge-shaped edge portion which interiits the wedge-shaped groove 17 in the side walls of the screen chamber. The screen may be inserted slidably through the opening in the rear cover 50 when the plate 59 is removed.

The preferred form of piston 72 is shown in Figs. 2 and 3. It has a central plate 73 of somewhat smaller diameter than the cylinder liner 22, a pair of piston cups 74 lying on opposite sides of the central plate 73 with their edge flanges disposed outward, and a pair of side plates 75 having raised central bosses. A peripheral series of spring fingers on a spring member 76 may be used to yieldingly support the anges of the cups 74 against the cylinder walls.

The piston is carried by a piston rod 68 slidably mounted in the bearings 41 and 51 and projecting through the rear cover 50. The main portion of the rod 68 has a forward reduced shank 69 threaded to receive a rod extension 70. The piston parts 73 to 76 are assembled on the shank 69 and clamped between the main portion of the rod and the rod extension 70, and the assembly is desirably locked by means of a set screw 71 screwed into the end of the extension 70 against lthe shank 69.

A modified form of piston is shown in Fig. 4. In this modification, the piston comprises a spacing ring or disk 77, two side plates 78 similar to the plates 75 in Fig. 2, and a molded ring member 79 held between the plates 78. The member 79 has a cross section generally in the form of a T to form a central tongue received between the plates y78, and oppositely extending flanges to engage the wall 22 of the cylinder. The piston may include spring members similar to the members 76 of Fig. 3, but the ring 79 is best made of material which itself has sufficient resilience to support the flanges against the wall of the cylinder. The parts of this modified piston are desirably held together in a self-contained sub-assembly, as by rivets passed through the plates 78 and the tongue of the ring member 79.

VThe valve plates 40 are flat sheet metal stampings of circular outline and of a size to overlap the ends of the cylinder wall. Each is punched with a central rodpassing opening 45, with two valve openings 46 respectively above and below that central opening 45, with two holes 47 to pass screws into the bosses 43 of the cover, and with two semi-circular notches 48 positioned to lie in alignment with the outer ends of the grooves 38 of the cover. The plate 40 may also be partially punched to provide studs 49 to locate the valve cages.

The two valve openings 46 of the valve plate 40 are respectively positioned to communicate with the inlet and discharge passages 33 and 34. The lower opening is beveled on vthe inside to provide a conical seat 80 for the inlet valve, and the upper opening is beveled on the outside to provide a conical seat 82 for the outlet valve. The inlet valve yis 'desirably formed as a sheet metal stamping with the side flanges formed to mate with the conical seat 80, and is secured to a stem 84. The valve is supported by 'its' stem 84 in a cage 86 located on the valve plate 40 by the studs 49 and fastened thereto as byserews threadedj into the plate. The valve is urged to vclosed position by a'spring acting between the cage 86 and a washer 85 mounted on the outer end of the stem 84. The 'outlet valve 88 is also a sheet metal stamping, which may be identical with that of .desirable in handling volatile gasoline fuels.

the inlet valve 83, assembled to a stem 89. It is -supported by the stem in a cage 90 located on and fastened to the valve plate 40. It is urged to a closed position by a coil spring acting between the cage 90 and the valve 88.

The special sealing member between the valve plate 40 assembly and its associated cover comprises a central ring 92 with two radial arms 94 extending therefrom and having short end portions or tips 96 lying at right angles to the plane of the ring `and arms. The ring 92 and arms 94 are of uniform thickness, and desirably of circular cross section. The tips 96 are conveniently of similar cross section, and are of a height substantially equal to the thickness of the valve-plate. The sealing member is desirably of rubber or rubber-like material, molded to the desired shape.

Each valve plate 40 is assembled to its associated cover 30 (or 50) with a sealing member therebetween. The central ring 92 of the sealing member overlies the end face of the boss 35 (or 55) outside the breathing passages 42, the arms 94 lie in the grooves 38 in the top of the walls 36, and the end portions 96 lie in the notches 48 and are compressed between the plate 40 and the surrounding inner edges of the flange 31. Two :screws threaded through the plate openings 47 into :the bosses 43 secure the parts together with the sealing member compressed between them, to form a resilient, effective, yand long lasting seal. Such seal separates the inlet and outlet passages 33 and 34 from each other :and fromthe space within the boss 35 (or 55). Its arms 94 are supported by the ridges 37 on the walls 36 to prevent displacement. Its end portions 96 prevent leakage along the periphery of the plate 40.

Each sub-assembly of cover and valve plate presents a planar face which may be sealed to the end face of the valve body by a simple punched sheet gasket. That gasket underlies the edges of the valve plate 40 to seal that plate to the end of the cylinders, and is also engaged directly between the anges of the cover and body, to seal those parts independently of the seal between the valve plate 40 and the cylinder.

The pump is assembled by rst forming the s'ubassemblies of valve plates and covers, and then attaching those sub-assemblies to the body 10 and inserting a piston and piston rod assembly.

The projecting end of the piston rod is pivotally attached to the handle 66, and the lower end of the handle is connected by the fulcrum links 64 to one of the handle supports 62. Either such support 62 may be used, depending on the desired position of the handle.

For corrosion resistance, certain parts only of thepump need be made of corrosion resistant material. For example, stainless steel may be used for the piston rod 68--70, the cylinder liner 22, the valve Iplates 4t), the valves 83-84 and 88-89, the valve cages 86 and 90, the valve springs, the screws which hold the valve plate assembly, and the screen. The bearings are desirably also made of corrosion resistant material, and Vmay be made of a synthetic plastic such as nylon, of bronze, or of other suitable material. These parts are all of simple sheet or bar stock and are readily formed by simple machining or stamping operations. The body and cover castings receive no wear. They can be made of materials most suited to die casting and most desirable for other characteristics, and they can be protected from corrosion by coating their interior and exposed surfaces with corrosion resistant paint. Similarly, the metal parts of the piston can be protected by paint, and need not be of corrosion-resistant metal.

The pump is convenient for manual operation and provides high efliciency and a high displacement ratio, Constructed as shown and described, the pump is compact, light in weight, and relatively inexpensive lto manufacture in production. The valve plates `and valves may be made as sheet-metal stampings, and the luse of such plates permits all internal pump chambers and passages to be made as cavities which freely open through the mating faces of the body and covers and with walls of generally uniform thickness, and this in turn permits the body and covers to be made as die castings which require little machining. The special seal between the at valve plate and the transverse wall separating the inlet and outlet passages of the cover contributes essentially to this result and permits an elective and simple assembly of sheet-metal and die-cast parts. The special form and position of that seal avoids need for a seal between the valve plates and the piston rod, Vand permits the bearings and seals for the rod to be formed in the die cast covers and to be exposed through the rod-passing openings 45 of the valve plate to the cylinder. The construction of the pump permits it to be made corrosion resistant with the use of a minimum amount of corrosionresistant metal for but a few simple parts. I

We claim as our invention:

1. A double-acting piston-pump, comprising a body having end faces, a cylinder extending end-to-end through said body, a sheet-metal valve-plate gasketed against each end of said cylinder and having a central rod-passing opening, a cover secured over each valve plate against each body end-face and having a central 4boss surrounding a bearing area, the inner edge of said boss extending into proximate abutment with the adjacent valve plate about its central opening, webs extending generally radially from said boss and dividing said cover to form inlet and outlet passages on opposite sides of said boss, the edges of said webs extending into proximate abutment with the adjacent valve plate, intake valves in said valve plates opening from the inlet passages to said cylinder, outlet valves in said valve plates opening from said cylin der to the outlet passages, a sealing member between each valve plate and the inner edges of the boss and webs of its overlying cover, sealing the inlet and outlet passages from each other and from the central rodpassing opening in the valve plate, a rod slidably journaled in said cover bosses, and a double acting piston carried by said rod.

2. A double-acting piston-pump as defined in claim 1 with the addition that said sealing member seals said passages from the central 'bearing area of the boss, and that said rod is received in one of said bosses in a blind hole therein, and means to vent said blind hole to the valve-plate abutting end of its boss inside the said central bearing area sealed from said passages.

3. A piston pump, comprising a body forming a cylinder, a sheet-metal valve plate closing the end of the cylinder and having a central opening, a piston in said cylinder, a piston rod passing through said valveplate opening, a cover over said valve plate and having -a bearing boss extending toward said valve plate about the central opening thereof, transverse walls joined to said boss and extending toward said valve-plate, said boss and walls dividing said cover to form inlet and outlet passages, valves in said Valve plate which open respectively from and to said inlet and outlet passages, and a sealing member of rubber-like material and of round crosssection having a central annular portion lying between the bearing boss and valve plate about the central opening thereof and having integral arms radiating from said annular portion and lying between said transverseV walls and the valve plate, sealing the inlet and outlet passages from each other and from the central opening of the valve, the valve-plate-facing edges of said transverse wall being formed with longitudinal grooves receiving and retaining said arms, and thereby positioning said annular portion.

4. A. piston pump comprising a body forming a cylinder opening through a body end-face, a cover secured to said end face, a sheet-metal valve plate confined between said end face and cover, said cover having a dividing wall and containing cavities on opposite sides thereof open to said vval-ve plate .and to which edge portions Aof the valve plate are exposed, said cavities yand valve plate defining inlet and outlet passages for fthe pump, sealing means between said valve plate and cylinder, sealing means between the face of said valve plateand said dividing wall, and sealing means at the edge portions of the plate bctween said cavities.

5. A piston pump comprising a body forming a cylinder opening through a body end-face, a cover secured to said end face, `a sheet-metal Valve plate confined between said end face and cover, said cover having a dividing wall and containing cavities on opposite sides thereof open to said valve plate and to which edge portions of the valve plate are exposed, said cavities and valve plate defining inlet and outlet passages for the pump, a gasket between said valve plate and cylinder, and a sealing member between said dividing wall and the face of said valve plate and extending across edge portions of said valve plate adjacent the ends of Said dividing wall into engagement 4with said gasket.

6. A piston pump as defined in claim 5 with the addition that said sealing member is of substantially circular cross -section'and the seal-receiving edge of said dividing wall is formed to provide a seal-supporting groove.

7. A piston pump suitable for die-cast construction, comprising a body having parallel planar end faces and forming a cylinder extending from end to end therethrough, inlet and outlet ypassages extending from end to end therethrough outside and parallel with said cylinder, said passages being open through said end faces and having `side walls which diverge outward to permit die withdrawal, cover members having faces to meet the end faces of said body, said covers containing inletand outlet-passage cavities open over their whole area at said meeting faces and defined by walls which diverge toward Vsaid faces to permit die wtihdrawal, said cavities having central portions positioned to overlie the ends of the cylinder opening and outer portions in open communication therewith and respectively positioned to overlie the inlet and outlet passages of said body, a valve-plate seat at the interface between each cover and the body, a Valve-containing plate in each seat closing its end of the cylinder and terminating short of the outlying inlet and outlet passages of said body, said valve plate thereby providing interface -walls for the central portions of said cavities to form inlet and outlet passages in said covers leading to the inlet and outlet passages of said body.

8. A piston pump suitable vfor die cast construction, comprising a pump body having a planar end face, a cylinder formed therein and opening through said end face, inlet and outlet passages in said -body outside and parallel with said cylinder, said passages opening through said end-face and having side walls which diverge outward to permit die withdrawal, a cover having a face to meet said body and end-face, said cover containing-inletand outlet-passage cavities open over their whole area at said meeting face and defined by walls which diverge towards said face to permit die withdrawal through the plane of said face, said cavities having central portions to overlie the cylinder opening of said body and outer portions -respectively positioned Vto overlie the inlet and outlet passages of said body, a valve-containing plate seated between said cover and body and closing vthe cylinder end while leaving open the inlet and outlet pas- "8 sages in said body, said plate lproviding an interface wall for .said central portions ofthe cover lcavities and thereby forming inlet and outlet passages communicating with the corresponding passages in said body.

9. A piston pump suitable for die cast construction, comprising a body having a planar end face, a cylinder formed in said body and open through said end face, a chamber in said body outside said cylinder and parallel therewith, said .chamber being open through said endface and having side walls which diverge outward to permit die withdrawal, a cover having a separation face parallel with said body end face, a cavity formed in said cover open over its whole area through said separation face and defined by walls which diverge towards said face to permit die withdrawal, said cavity having a central portion opposite the end of said cylinder and an outer portion forming a continuation of said body chamber, and a yvalve-containing .plate seated ybetween said cover and body and closing said cylinder while leaving said body chamber .and its -cover continuation in open ycommunication, said plate thereby providing an interface wall for the central portion of said cover cavity and forming therewith a fluid passage.

10. A piston pump construction as defined in claim 9 with the addition of an intake in the wall of said -body chamber, alined grooves formed in opposite walls of said body chamber and its cover continuation and a screen having its edges received in said grooves to position the same in said body chamber and its cover continuation between said intake and the fluid passage formed in said cover.

l-l. A double-acting piston pump, comprising a central body having end faces, a cylinder extending from end to end through said body, inlet and outlet passages extending from end to end through said body outside said cylinder, valve-containing plates over the ends of the cylinder, and covers assembled to the body and containing inlet and outlet passages fully open through the bodyfacing face of the cover and extending from points 0pposite the cylinder outwardly and into communication respectively with said body passages, said valve-containing plates being retained against the cylinder end by engagement of the cover therewith in areas outside ythe passage interface opening areas, the plate portions overlying said interface opening areas extending thereacross as free bridges unsupported from said cover and inlet and outlet connections communicating with said body passages. Y

12. A double acting vpiston pump as defined in claim 11 with the additionof a planar screen positioned longitudinally in said intercommunicating inlet passages.

'References Cited in the tile of this patent UNITED STATES PATENTS

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