US 3468257 A
Description (OCR text may contain errors)
Sept. 23, 1969 s. KOF'lN-K 6 LIQUID PUMP VALVE ACTUATING ARRANGEMENT Filed Sept. 18, 1967 2 Sheets-Shee 1 I 27 SIEGFEIEDWHZE;%%NK F IG. I
Sept. 23, 1969 s. KOFINK 3,468,257
LIQUID PUMP VALVE ACTUATING ARRANGEMENT Filed Sept. 18, 1967 2 Sheets-Shee 2 27 M H G 2 am/Ea wig/K 4 7'TOPNEYS United States O".
3,468,257 LIQUID PUMP VALVE ACTUATING ARRANGEMENT Siegfried Kofink, Zell (N eckar), Germany, assignor to J. Eberspacher, Esslingen, Germany Continuation-impart of application Ser. No. 627,713, Apr. 3, 1967. This application Sept. 18, 1967, Ser. No. 668,542 Claims priority, applicatgtintagfrmany, Apr. 2, 1966,
E Int. Cl. F04b 17/04, 7/02 US. Cl. 103-53 7 Claims ABSTRACT OF THE DISCLOSURE A liquid pump of a type which includes a reciprocable pump piston which is actuated by means such as an electromagnet includes a pumping space into which the liquid is pumped by movement of the piston to pump the liquid either through a bore defined in the piston itself or a bore defined in the cylinder walls. The liquid which moves into the pumping space will be discharged from this space upon the lifting of a discharge valve to permit passage of the liquid from the space through a discharge opening. The invention concerns the construction of a valve which closes ott the passage from the pumping chamber to the discharge and which is biased downwardly to close off a valve seat formed between the pumping chamber and the discharge. The valve construction in one embodiment is made such that its stem portion extends into the pumping chamber at a location where it will be contacted by the piston near the end of each pumping stroke. The piston moves through a stroke which causes it to lift the valve upwardly and to cause the fluid flow through a passage defined in the valve stem and out to the discharge. Thus, the control of the valve is accomplished directly by the movement of the pump piston. In a further embodiment, the valve comprises a ball which is adapted to close the valve seat and which will be moved upwardly upon contact of an extension of the piston therewith which pushes the ball upwardly against the downward holding force of a valve spring.
CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of application Ser. No. 627,713, filed by the present inventor on Apr. 3, 1967.
The invention disclosed herein is an improvement over that disclosed in Patent No. 3,302,582.
SUMMARY OF THE INVENTION This invention relates, in general, to liquid pumps and, in particular, to a new and useful liquid piston pump particularly for pumping fuel having a reciprocating piston which is moved by an electromagnet and which is arranged to move through a path such that it will actaute a. valve for permitting the discharge of the pumped fuel.
The present invention is particularly described in respect to a piston-type pump in which the piston is actuated or moved electromagnetically, but the same principle applies to any piston-type pump. Fuel is supplied to a pumping chamber which is arranged at one end of the pumping piston either directly through a passageway defined in the moving piston or through a passageway defined in the surrounding structure of the housing or piston cylinder. The fuel is delivered by movement of the piston to an intermediate chamber or pumping chamber Patented Sept. 23, 1969 c we which is closed at its opposite end by a valve which is held against a valve seat by means of an adjustable valve spring. The valve seat is located in a chamber which communicates with a liquid discharge. It is known with pumps of this type to control the flow of fuel only indirectly through the movement of the piston. For this purpose, a spring-loaded valve is customarily moved from its position independent upon the pressure which occurs during the movement of the piston and which acts on the valve to cause the lifting of the valve after a predetermined pressure is reached. The valve which is thus moved by the prevailing pressure then permits passage of the medium to be conveyed.
A disadvantage of the known pumps is that when the pumping action is initiated or started, that is, during the first strokes of the piston, air is fed and the feeding of the air must necessaril take place against considerable resistance or bias. A further significant disadvantage resides in the fact that the efiiciency of this type of pump is very much dependent on the pressure drop. This dependency on the pressure drop is more pronounced the higher the pressure. For example, the pressure of gasoline in a gasoline tank is relatively high.
In accordance with the present invention, the disadvantages of the prior art are overcome by constructing the pump so that the piston may cause the movement of the valve to open the valve during the pumping operation. In one embodiment, this is accomplished by providing a valve which has a valve shaft portion which extends downwardly into the intermediate pumping chamber at a location where it is contacted by the piston or an extension thereof during the piston movement. This causes the lifting of the valve at the desired time to permit flow of the liquid out of the pumping chamber and through a discharge passage. The construction is such that the position of the valve and the force of a spring acting thereon may be adjusted by means of an adjustable abutment pin which is centered within the coil spring which biases the valve to a closed position. In a further embodiment, a ball valve is employed to close a valve seat and it is biased to a closed position by a spring which fits over an abutment pin and engages around the ball at its opposite end. In this embodiment, the piston is provided with an extension which moves to engage the ball and to lift it off its seat when the pumping action is desired. In both embodiments, the control of the valve is accomplished directly by the movement of the piston. This has the advantage that the spring force which acts on the valve and which prevents premature opening of the valve can be chosen of such a magnitude that a reliable opening of the valve is assured during the initial period of the pumping procedure, that is, during the time period to which air is still pumped from the conduits. This is possible because the opening of the valve is directly accomplished by the pump piston by direct contact between the pump piston and the valve.
Accordingly, it is an object of the invention to provide an improved pump construction in which a pump piston is arranged in association with a discharge valve which seals the pumping chamber from a discharge so that the valve is operated by the direct movement of the piston.
A further object of the invention is to provide a pump which includes a movable piston arranged to pump a liquid into an intermediate pumping chamber which is closed from a discharge by means of a valve and which includes an abutment pin for centering a biasing spring so that it may act against the valve to close it against the valve seat, and wherein means are provided to directly connect the pump to the valve for moving the valve off its seat upon a predetermined movement of the pump piston.
A further object of the invention is to provide a pump which is simple in design, rugged in construction and economical to manufacture.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:
FIG. 1 is a transverse sectional view of a fuel pump constructed in accordance with the invention;
FIG. 2 is a view similar to FIG. 1 of another embodiment of the invention.
DETAILED DESCRIPTION OF THE DRAWINGS Referring to the drawings in particular, the invention embodied therein in FIG. 1 comprises a cylindrical housing generally designated 20 which is open at one end. A magnetic coil 22 is positioned around a central hollow cylindrical formation 20a of the housing. A pump piston 3 is slidable within the cylindrical formation 20a and it carries an armature 24 at one end which is made of a magnetic material and will be oscillated under the infiuence of the coil 22.
A return spring 26 made of a nonmagnetic material such as rubber is arranged around the piston 3 and bears at one end on a ledge 20b of the housing and at its opposite end against the armature 24.
Excitation of the coil 22 causes the reciprocal movement of the piston 3 and the bringing in of fuel through an inlet 27 and around the armature where it is pumped upwardly through a passage 28 defined in the cylindrical portion 20a. The liquid exits from the upper end of the passage into a pumping chamber 2 which is closed at the upper end by a fitting 30 defining a valve seat covered by a valve 6. The valve 5 is provided with a shaft portion 5a which extends downwardly through a cylindrical passage 32 and projects at its bottom .end into the pumping chamber 2 by an amount indicated A. The valve stem 5a is provided with a groove 9 for the upflow of the fuel when the valve 6 is lifted ofl? the seat. The top of the valve 6 is provided with a projecting portion or abutment 6b which provides a centering means for a biasing spring 8 which is engaged around an abutment or pin 7 which may be adjusted in position by means of an adjusting knob portion of a fitting 34. The fitting also defines a discharge passage for the fuel which is pumped upwardly beyond the valve 6.
When the coil 22 is energized by passing current through the connecting wire 36, the pump piston 3 is oscillated through a stroke path which causes the upper end to contact the valve stem 6a and to move it upwardly off the seat at a time corresponding to a desirable pumping time of the cycle.
An alternate embodiment of the invention is indicated in FIG. 2, wherein similar parts are similarly designated, but with the addition of a prime to each numerically designated part. In this embodiment, the piston 3' is provided with a projection 4' which is movable in a cylindrical space 32 of the pump. At the upper position of the movement of the piston 3', the upper end of the projection 4' contacts a ball-type valve 6 which is lifted off the seat by this piston action to communicate the discharge 10' with the pumping passage 2. The ball valve 6 may be moved by an amount A off the valve seat 5' which corresponds to the amount of movement of the valve 6 in the embodiment of FIG. 1. The passage 9' which is defined in the cylindrical part 32' is formed around the projection 4'.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
What is claimed is:
1. A liquid pump comprising a pump cylinder having a pump chamber, an inlet for liquid connected to said pump chamber, a piston reciprocatable in said pump cylinder including a portion in said pump chamber movable to bring liquid in said inlet and deliver it to said pump chamber, a liquid discharge, means defining a passage extending alongside said piston from said pump chamber to said liquid discharge, a valve seat in said passage, a valve for closing said valve seat, means biasing said valve into seating engagement on said valve seat to close off said passage, electromagnetic means adjacent said piston for moving said piston backwardly and forwardly in said pump cylinder, and means in the path of movement of said piston and movable thereby to move said valve against the force of said biasing means to open said passage to permit discharge of liquid through said discharge.
2. A liquid pump, according to claim 1, wherein said means in the path of movement of said piston comprises an extension of said valve extending away from said valve seat toward said piston.
3. A liquid pump, according to claim 1, wherein said means in the path of movement of said piston comprises an extension of said piston movable through said passage to engage said valve to lift said valve off said valve seat.
4. A liquid pump, according to claim 1, wherein said means in the path of movement of said piston comprises said valve, said valve including a portion adapted to sit on said valve seat, and a stem portion extending through said passage and projecting out of said passage into said pump chamber, said stem portion being contactable by movement of said piston to open said valve when said piston is moved through said pump chamber.
5. A liquid pump comprising a pump cylinder having a pump chamber, an inlet for liquid connected to said pump cylinder, a piston reciprocatable in said pump cylinder to bring liquid in said inlet and deliver it to said pump chamber, a liquid discharge, means defining a passage from said pump chamber to said liquid discharge and a valve seat in said passage, a valve for closing said valve seat, means biasing said valve into seating engagement on said valve seat to close off said passage, and means in the path of movement of said piston and movable thereby to move said valve against the force of said biasing means to open said passage to permit discharge of liquid through said discharge, said biasing means including a coil spring, said valve having a projection thereon for centering one end of said spring thereover and a projection carried on said pump cylinder and projecting into the passage over said valve and centering the opposite end of said spring.
6. A liquid pump, according to claim 5, including means for adjusting the position of said projection for centering said spring and for varying the compression on said spring.
7. A liquid pump comprising a pump cylinder having a pump chamber, an inlet for liquid connected to said pump cylinder, a piston reciprocal in said pump cylinder to bring liquid in said inlet and deliver it to said pump chamber, a liquid discharge, means defining a passage from said pump chamber to said liquid discharge and a valve seat in said passage, a valve for closing said valve seat, means biasing said valve into seating engagement on said valve seat to close 01f said passage, means in the path of movement of said piston and movable thereby to move said valve against the force of said biasing means to open said passage to permit discharge of liquid through said discharge, said biasing means comprising a coil spring, said valve having an abutment thereon, said coil spring having one end surrounding said abutment, and an abutment pin projecting into said passage toward said valve and being 2,557,880 6/1951 Lynn 103-166.5 XR adjustable in respect to its distance from said valve and 2,761,391 9/1956 Johnson 103227 XR providing a centering means for the opposite end of said coil spring. ROBERT M. WALKER, Primary Examiner References Cited 5 UNITED STATES PATENTS 1,486,498 3/1924 Smith 230-203 103227 1,690,348 11/1928 Wallace 10353 XR