US2442631A - Pump - Google Patents

Description

June 1, 1948. A. H. WINKLER FUN? ' Filed Nov. 30, 1944 4 1 M my /0 0 I W. z 0 A W. M V x z W 6 ,0 w 6 M m y m av x W J w W. fl fl 1 W w. a J, H 3 w l u m x d f W Wv 5 by #45527 H Mme? ATI'QRIVEY Patented June 1, 1948 Aibert H. Winkler, South Bend, Ind,

'- arts Bendix Aviation commute, South Be, a. a corporation of Delaware Application November 30, 1944, Serial No. 585,933

8 Claims. (Cl. 103-227) 1 This invention relates generally to fluid pumps and has particular reference to positive displacement pumps. This application has subject mat-- ter in common with applicants co-pending application Serial No. 500,893, filed September 2, 1943, the present invention being an improvement over the type of pump shown in Figures 5, 6 and 7 of said copending application.

While the invention in its broader aspects may i be incorporated in pumps of various types and for various purposes it is shown and described herein incorporated in pumps of the positive pressure type for supplying fuel to charge forming devices or the like. In pumps of this character considerable difilculty has been encountered in eiiecting filling or priming of the pump chamber or chambers when the pump is started empty and it is therefore an important object of the present invention to provide a pump wherein rapid filling of the pump chamber or chambers may be automatically effected when the pump is started empty.

Another object of the invention is to provide a After consideringthis example, skilled persons will understand that many variations may be made without departing from the principles disclosed, and I contemplate the employments of any structures, modifications or modes of operajtion that are properly within the scope of the appended claims.

. In the drawings:

Figure l is a diagrammatic view of a pump embodying the present invention; and

Figure 2 is a section taken on line 2-2 of Figure l.

Referring to the drawings there is disclosed, for the purpose of illustrating the present invention, a reciprocating type of pump which includes a body portion having a. cylinder I2 in which a piston or pumping chamber I4 is reciprocably disposed. The piston may be reciprocated by any suitable means, the means herein shown, by way of example, comprising a shaft I8 joumalled in the body portion In of said shaft and having a portion ll of reduced size eccentric relative to the axis of the shaft IS. The extension I! is disposed ln the cross bore of a block 20 slldable in a bore 22 in the piston i6 and at right angles to the axis thereof.

Fuel is supplied to the pump "by fuel supply conduit 24 from a suitable source of fuel, said conduit being connected with a fuel inlet 26 of the pump, the fuel passing into the interior of the cylinder by way of a port 28 of such size and so located as to be in constant communication with an opening 80 into the cross bore 22 from which it passes into the chamber-like portions 3| at the opposite ends of the piston by way of ports 32. Both ends of the piston ii are closed by walls 34. The pump is of the doubleacting type andinasmuch as each side is constructed, and operates in the same manner, a

, description will be given herein of but the left hand side, as shown in the drawings. The wall or head of the piston 34 is provided with fuel passages 30 and the flow of fuel from the interior oi the piston through said passages 36 into a chamber 38 is controlled by an inlet check valve 40 which comprises a rigid plate member 42, preferably of metal, attached to a valve stem 44 which extends into the piston and is substantially coaxial therewith. The plate member 42 carries a sealing gasket 48 (of neoprene or other suitable material) having a peripherally inturned portion 41 adapted to engage the outer surface 01' the piston wall or head 34 encompassing the area thereof containing the ports 35. A conical spring 48 is secured to the valve stem 44 adjacent the free end thereof and reactsbetween the point whereat it is secured to said stem and the interior surface of the piston wall or head 34 thereby normally maintaining the valve in the closed position and preventing flow of fuel into chamber 38. An outlet check valve, generally indicated at 50, is provided and comprises a cup-shaped member, which is of rigid material, preferably metal. The member 5| has an outwardly extending flange 52 about the open,

of a rivet 59. there being a reinforcing plate till secured by said rivet on the side of the diaphragm opposite the valve 50. It is to be noted that the marginal edge portion of the plate is turned laterally away from the diaphragm to protect the latter from being cut or otherwise injured by the edge of said plate. The diaphragm is marginally secured between the end ofthe body member [0 and a cap 84 thereby forming an expansion chamber 66 which may be considered as extending between the valve seat Si and the diaphragm 58 and posterior to the chamber 38. The cap 64 is cup-shaped to provide, a spring chamber 68 3 in which is disposed a calibrated spring 18 adapted to react between the outer end or bottom wall of said cup and the plate 88 for urging the valve 88 closed. If desired the chamber 88 may be in communication with the atmosphere by means of passages 12 and 14. Alternatively the chamber 88 may be connected with an air scoop, supercharger'or the like in which case the passage 18 is suitably connected therewith by means of a conduit 18. The purpose of such an arrangement is to properly balance the valve 88 at all times and therefore the relative fuel pressure is unaffected by changes in pressure occurring at the inlet opening. of the carburetor. bein supplied with fuel by the pump.

In the arrangement herein disclosed the closed end portion of the valve 88 is so positioned and the stroke of the piston is of such length that the head 18 of the valve stem 88 of the inlet valve will engage the head 88 of rivet 88 as the piston approaches the outer limit of its stroke and when said piston has reached said outer limit the valve 88 will be slightly unseated. The pump is also provided with a fuel outlet 82 connected with the expansion chamber 88 by a passage. said outlet 82 being connected with a discharge conduit 88 which leads to the carburetor or any other device to be supplied with fuel.

Operation The pump is operable independently of the direction of rotation of the drive shaft i8. it bemain in chambers 38 and 88 and no additional ing of the double-acting. positive displacement type. Upon rotation of the shaft IS the piston I4 is reciprocated in the cylinder l2 and, assuming that the pump is full of fuel. said fuel during the intake stroke of the piston is drawn into the inlet 28 and passes through the port 28 and pasvalve 88 is closed during the intake stroke, and

the inlet check valve 48 opens to permit the passage of fuel therepast. When the piston reaches the end of its intake stroke the inlet valve 88 is closed by the spring 88 and as the piston moves through its discharge stroke the pressure of said piston transmitted through the fuel in chamber 88 forces the outlet check valve 50 open, discharging said i'uel into the chamber 86 and thence through passage 88, outlet 82 and discharge conduit 88. The device will operate as above described as long as the outlet is unrestricted. Under such operating conditions thediaphragm 88 will be forced outwardly a very limited extent against the resistance of spring '10. Should the outlet be partially restricted so that there is but a limited discharge of fuel the pressure developed in chambers 88 and 88 force the diaphragm 88 further to the left during the discharge stroke of the piston, the outward movement'of the diaphragm effecting an enlargement of chamber 88 sufficient to take care of the difference in normal decrease in the volume of chamber 38 and the quantity of fuel discharge per stroke of the piston. Inasmuch as the outlet valve is controlled by the movable wall or diaphragm 88 the quantity of fuel drawn into the pump by the intake stroke of the piston will depend on the quantity of fuel in chambers 38 and 88. For example, should the outlet of the pump be restricted so that but one half of the maximum capacity thereof be disa fuel will be drawn into the pump cylinder until the piston has travelled through the initial half of its intake stroke during which the excess fuel in chambers 38 and 68 will be returned to the cylinder under the force of spring 18. When this excess fuel has been returned to said cylinder the diaphragm has reached a position whereat the valve III is closed. Thereafter said valve provides an inflexible end wall for the cylinder and further movement of the piston on its intake stroke will draw more fuel into the pump. Should the flow from the outlet 82 be entirely out off the diaphragm 88 would merely oscillate back and forth so as to maintain the volume trapped in chambers 38 and 88 constant notwithstanding the 'is anterior to the expansion chamber 88 and that the position of the diaphragm controls the position of said check valve 58. the position of said diaphragm being. of course. determined by the quantity or volume of fuel discharged through the chamber 88.

It is to be further noted that certain diiliculties may be encountered in devices of this character when a diaphragm is used as onewall of the expansion chamber and the fuel is drawn from a source by the pump suction. These difllculties arise from the tendency of portions of the diaphragm between the centrally reinforced portion and marginally clamped portion to oscillate back and forth and prevent the building up of pressure for the discharge of fuel from the pump. and the intake of the fuel during the intake stroke of the piston. However, the foregoing difllculty is overcome in the present invention by providing the large valve 88 which forms an inflexible end wall for the chamber 38 and insures the drawing of fuel into said chamber during the intake stroke of the piston. Otherwise during said intake stroke of the piston the above mentioned flexible portion or the diaphragm would merely be drawn toward the retreating piston and prevent establishment of the necessary pressure differential for drawing more fuel into the pump and during the discharge stroke said portions of the diaphragm will be forced outwardly and there would be no discharge of fuel.

Priming Should the pump be started dry the chambers 88 and 68 would be filled with air as well as the interior of the piston and the conduit leading from the fuel supply source to the pump. Due to the compressibility of the air, considerable difficulty would be encountered in clearing the above mentioned parts of air. In order to overcome this difllculty the parts of the present invention are so constructed and arranged that, as above pointed out, when the piston approaches the end of its discharge stroke the head 18 of the valve stem 44 contacts the head 88 of the rivet 88 and positively forces open the valve 88 a limited amount thus permitting the air compressed in chamber 88 to escape into the chamber 88 and thence through the passage 84, outlet 82 and conduit 88. With this arrangement the air may be rapidly cleared from the parts above mentioned and fuel drawn into and discharged by the pump. It is to be further noted that it has been found that this arrangement has no material adverse aifect on the eificiency of the pump under normal operating conditions.

It is thought that the invention and many of the foregoing description and though said invention has been illustrated and described in connection with but a single embodiment it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinabove described being merely a preferred embodiment.

I claim:

1. In a reciprocating pump: a cylinder having an open end; a reciprocable pumping member mounted in the cylinder and having its head adjacent the open end of said cylinder; a flexible diaphragm forming one wall of an expansible chamber at the open end of the cylinder; a substantially inflexible outlet valve carried by the diaphragm andadapted to close the open end of the cylinder and providing a second chamber between said valve and the head of the reciprocable member; and a valvev controlled inlet passage communicating with the second chamher; said outlet valve being adapted to be mechanically engaged by the reciprocable member as the latter approaches the end of its discharge stroke and to be at least slightly unseated thereby when said member reaches the end of its discharge stroke.

2. In a reciprocating pump: a cylinder having an open end; a piston in said cylinder, said piston having a head; an inlet passage in said head; an inlet valve carried by the piston and controlling said passage; a flexible diaphragm forming one wall of an expansible chamber adapted to communicate with the inlet passage; a substantially inflexible outlet valve. carried by the diaphragm and adapted to close the open end of the cylinder and form one wall of a second chamher, said second chamber being between said expansible chamber and the head of the piston; said outlet valve being adapted to be engaged by a portion of the inlet valve as the piston approaches the end of its discharge stroke and to be unseated when the piston is at the end of its discharge stroke.

3. In a double-acting reciprocating fuel pump:

a cylinder; a pumping member reciprocable in said cylinder; a generally cup-shaped outlet valve capping each end of the cylinders and forming chambers between said outlet valve and the respective ends of the pumping member; flexible diaphragms carrying the respective outlet valves and forming walls of expansible chambers; springs urging the diaphragms in a direction to close-the outlet valves, said springs being of predetermined calibration; and valve controlled inlet passages for the pump; said pumping member being adapted to engage the respective outlet valves as said member approaches the end of respective discharge strokes and to efiect at least a limited positive opening of said valves when said pumping member reaches the end of the respective discharge strokes.

4. In a reciprocating pump: a cylinder having an open end; a reciprocating pumping member mounted in the cylinder; a flexible diaphragm forming a wall of an expansible chamber adjacent the open end of the cylinder; a substantially rigid outlet valve mounted in said chamber and adapted to close the open. end of the cylinde spring means resiliently urging said outlet valve to its closed position; said'valve being displaced by fluid pressure during each discharge stroke 6 of said pumping member; and a valve-controlled inlet passage for conducting fluid to be pumped to said expansible chamber.

5. In a reciprocating pump: a cylinder having an open end; a reciprocating pumping member mounted in the cylinder and having a head movable adjacent the open end of the cylinder; 8. flexible diaphragm providing a wall of an expansible chamber at the open end of the cylinder; a substantially rigid outlet valve carried by said diaphragm and adapted to close the open end of the cylinder and providing a second chamber between the outlet valve and the head of the reciprocating member; a spring urging the outlet valve to closed position, the outlet valve being displaced by fluid pressure during each discharge stroke of said pumping member; and a valvecontrolled fluid inlet passage communicating with said second chamber.

6. In a reciprocating pump: a cylinder having an open end; a reciprocating pumping member mounted in the cylinder; a flexible diaphragm forming a wall of an expansible chamber'adjacent the open end of the cylinder; a substantially rigid outlet valve in said chamber connected to said diaphragm and adapted to close the open end of the cylinder;.a spring urging said outlet valve to its closed position; said diaphragm being adapted to modify the effective force exerted on said valve by said spring in response to a variable fluid pressure external of said expansible chamber; and a valve-controlled inlet passage for conducting fluid to be pumped to said expansible chamber.

7. In a reciprocating pump: a cylinder having an open end; a reciprocating pumping member mounted in the cylinder; a flexible diaphragm forming a wall of an expansible chamber adjacent the open end of the cylinder; a substantially rigid outlet valve mounted in said chamber operatively connected to said diaphragm and adapted to close the open end of the cylinder; 9, spring urging said outlet valve toward its closed position; means for subjecting the back side of said diaphragm to a source of variable fluid pressure for varying the effective force of the spring on said valve; and a valve-controlled inlet passage for conducting fluid to be pumped to said expansible chamber.

8. A pump comprising a pumping chamber, a reciprocable pumping member, inlet and outlet valves for said chamber, an expansible chamber communicating with said pumping chamber and having a spring loaded movable wall, means for subjecting the outlet side of said movable wall to its pumping stroke.

ALBERT H. WINKLER.

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

UNITED STATES PATENTS Number Name Date 72,820 Doane Dec. 31, 1867 1,535,643 Astrom Apr, 28, 1925 2,111,970 Gillen Mar. 22, 1938 2,134,782 Fourness Nov. 1, 1938

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