US2286302A - Liquid pump - Google Patents

Description

June 16, 1942. is. G. PARSONS LIQUID rum Filed Feb. 28, 1941 a 2 Sheets-Sheet l INVENTOR.

is 6', fir/190 5 BY 94 guw ATTORNEY.

June 1942. B. G. PARSONS 2,286,302

LIQUID PUMP Filed Feb. 28,. 1941 .2 Sheets-Sheet 2 INVENTOR. 5 6, /Z;/-s0/25 ATTORNEY Patented June 16, 1942 LIQUID PUMP Ben G. Parsons, Detroit, Mich., assignor to American Bosch Corporation, Springfield, Mass., a corporation of New York Application February 28, 1941, Serial No. 381,068

14 Claims.

This invention relates to liquid pumps and particularly to those for pumping gasolene, fuel oil,

water and other liquids in metered amounts per,

stroke, preferably beginning at a variable time in the pump stroke and ending at a fixedtime therein as is predetermined by an adjustment of the pump.

The primary object of the invention is to provide a small, compact and inexpensive pump of this kind of comparatively large capacity but light in weight and rigid in construction. One of the preferred features contributing to these characteristics is a hollow delivery plunger having a shaped peripheral rim in the form of one or a plurality of helices whereby the plunger may be turned to an adjusted angular position in its barrel in cooperation with one or'a plurality of inlet ports to predetermine the amount of liquid delivered per stroke through a delivery valve co,- axially arranged in the barrel, and whereby the return spring for the plunger may beat least partly housed therein in such manner as to react against the delivery valve directly.

Another object is to provide a desirable form of indicator for the adjustable delivery mechanism of a pump of this or other kind.

Still another object is to provide in a single cylinder pump of this or other kind an improved stationary filter arrangement for the liquid supthereof, whereby surplus liquid is returned from the barrel through the filter to assist in cleansing the filter.

The structural features and arrangements by which these and other objects and advantages are obtained will be understood from the following description taken in connection with the ac companying drawings, which show, as an example, the preferred embodiment of a single cylinder pump having a delivery valve and adapted in accordance with the invention for pumping gasolene as for instance to the nozzle of an internal combustion engine. Inthe drawings:

Fig. 1 is a central vertical section, partly in elevation, of the pump with the plunger in its lowermost position; Fig. 2 is a section on line 2-2 of Fig. 1; Fig. 3 is a section on line 3-3 of Fig. 1 but with the plunger in its uppermost position; and Fig. 4 is a section on line 44 of Fig. 3.

The/exterior housing of the pump is formed by a filter housing I of stainless steel and a pump housing plunger barrel 2 of a hard steel alloy synthetic rubber gasket 4. These two housings are held tightly on the gaskets by the hollow nut 5 threaded into the pump housing and seated on a gasket 6 onthe top of the filter housing, which nut also secures in place the delivery duct I extending from the outlet port of the pump to a nozzle in the engine manifold or cylinder in the well known manner. The pump housing is fastened by the bolt fastenings 8 to the cam shaft housing 9 ofduraluminum which is provided with 1 a base or flange mounting on the engine as detelescoped therein-for a portion of its axial length sired. This shaft housing has two end covers i0 fastened thereto by stud bolts ll, each cover having a ball bearing 12 for the shaft I3, and one carrying an oil seal I4 while the other closes the end of the shaft. The screw plugs l5 serve for filling and emptyingthe shaft housing with lubricant and the bolt fastenings 8 tightly clamp in fixed position the quadrant l6 having two scales H and I8.

Arranged concentrically within the stationary filter housing I is a filter comprising an annular filter cage I!) of stainless steel, also secured between the gaskets 3 and 4, and an annular filter screen 20 of any suitable kind as closely spaced bronze wires soldered to the cage at its upper and lower ends. ly arranged axial slots at 2| staggered in the upper and lower halves, and is readily exposed and The filter removed upon removing the housing I. housing has an inlet duct 22 and an outlet duct 23 communicating with each other by means of the channel 24 around the outside of the screen 20 so that, as gasolene is supplied continuously through the inlet 22, the outside surface of the screen is washed clear by the surplus gasolene of all adhering foreign particles including lint. This clearing action is facilitated and increased by the pump inforcing back through the filter some of each charge. of gasolene initially sucked into the barrel on the downward stroke of the plunger.

Centrally within the pump housing 2 is a through axial bore at 25 forming for the pump a cylindrical barrel in which reciprocates the delivery plunger 26 of a hard steel alloy. The plunger is forced upwardly in a sine wave characteristic movement by ring 21 mounted by means The cage has a plurality of circular- 4| with connecting portions.

mounted a return spring 32reacting between the crosswall 33 and the upper wall ofthe delivery valve 34, so as to return the plunger, as permitted by the ring 21, from the uppermost position shown in Fig. 3 to its lowermost .position plunger are repeated so long as the shaft I3 is and thereby eliminates the need for the usual tappet cup or roller. In the uppermost part of the plunger barrel, the bore thereof is enlarged to provide a conicalseat at 35 for the delivery valve 34 and for a threaded portion for the nut 5. The head of the delivery valve is of smaller diameter than the upper bore and has in it a cross channel as shown, so that when the delivery valve is lifted off its seat the gasolene flows along the conical seat and around the head to the delivery duct I. The delivery valve spring 38 reacts between the head 34 and the upper interior cross wall of the nut 5, and is stronger than the spring 32 in all operative stressed'positions of the latter.

The pump housing 2 has diametrically opposite inlet ports 39 from the annular channel 40 just inside the filter housing, and the upper peripheral rim of the plunger 26 .is formed into two longitudinally-extending oppositely-disposed helices These helices are so arranged with respect to the ports as to simultaneously cover and simultaneously uncover the latter at definite points in the reciprocation of the plunger depending upon the angular position to which the plunger is turned in the barrel. The adjusting mechanism for turning the plunger comprises an arm 42 loosely mounted for turning in an elongated slot at 43 in the pump housing (Fig. 4), and has a tongue 44 fitted in the vertical slot at 3| of the plunger. Thus the arm 42 can turn the plunger to any angular position in the barrel within limits defined by the quadrant or the slot at 43, and the plunger can be moved up and down in any such predetermined angular position between the lowermost and uppermost points to which it is reciprocated. In the assembled pump, the arm 42 is held from coming out of the slot 3| by the arcuate part of the quadrant Hi.

The operation of the pump will now be de-' scribed. Starting with the plunger 26 in its lowermostposition, the delivery valve 34 is seated and the inlet ports 39 are uncovered by the helices 4|, as shown in Fig. 1. At this time the space in the interior of the plunger and the barrel is filled with gasolene from the previous downward suction stroke of the plunger. As the shaft I3 is turned by a shaft of the engine with which it is associated, at cam shaft speed for a fourcycle engine and at crank shaft speed for a twocycle engine, the ring 21 forces the plunger upwardly. As soon as the ports 39 are covered by the plunger, the trapped gasolene is compressed until the pressure thereon sufficiently exceeds that effective to hold the delivery valve 34 closed. At that point in the pump cycle, the delivery valve is forced off its seat and gasolene delivered through the duct 1 for the remaining part of the upward stroke of the plunger. At the beginning of the downward or suction stroke of the plunger by the return spring 32, the delivery valve is closed by its spring 38 as a result of the decrease of pressure on the gasolene, and the pump barrel is filled with gasolene through ports 39. These alternating suction and delivery strokes of the directions of flow to the outlet duct 23.

turned by the engine, and thus gasolene is delivered to the nozzle in the manifold of the em gine or to the engine itself, or otherwise as desired, in timed relation with the cycle of operation of the engine.

The instant in the pump cycle of the beginning of delivery of gasolene, and therefore the instant in the cycle of the engine to which the pump is connected, is determined by the angular position of the plunger in its barrel because such position determines the.instant in which the helices 4| cover the inlet ports 39 in the upward or delivery stroke of the plunger to exert pressure on the gasolene in the barrel. Since the delivery of gasolene thereafter delivered continues until the end of the delivery stroke of the plunger, which end point coincides with the uppermost position of the plunger, the amount of gasolene delivered per stroke is concomitantly predetermined. Thus the position of the arm 42 indicates on scale H the angle through which delivery takes place, and at the same time indicates on scale I8 the percentage of the maximum amount of delivery of gasolene per stroke that occurs at that setting. Thus at the position shown in Fig; 2, the delivery extends for 60 out of a possible and the volume of gasolene delivered per stroke is 50% of the maximum. It will be observed that the gasolene constantly flowing through inlet duct 22 is greater than the maximum ever delivered by the pump. The surplus passes around the annular channel 24 in both In so doing the gasolene washes the outside surface of the filter screen 2|l and thereby carries away with it any solid or other foreign particles that may have been filtered out of the gasolene that passed through the filter screen. Since the screen extends completely around the pump barrel, the screen remains free of particles or other foreign matter that may otherwise clog it. In this way, the pump is more reliable and durable, and its metered accuracy of delivery is enhanced.

Also it will be observed that by making the plunger 26 hollow for a considerable portion of its axial length, which is practical for the pressure obtaining in the pump, its return spring 32 may be at least partly housed therein to thereby reduce the height and weight of the pump, and accordingly its strength and resistance to distortion in operation. Furthermore, by arranging the helices 4| on the rim of the plunger, the means for controlling the beginning of injection and the amount of fiow per stroke, which may be minute, may be accurately, simply and inexpensively attained in a pump of this kind.

While I have disclosed the preferred embodiment only of a single cylinder pump, it will be understood that many variations therein and modifications thereof may be made within the broad terms of the appended claims. For instance, the features herein noted may be applied to a multicylinder. pump, and may be used in single or multicylinder form for pumping liquids other than gasolene. Also the filter may be arranged outside the pump, instead of being incorporated in it, and the adjusting and indicating mechanism may be of other form and operated either manually or by a governor controlled automatically by the engine.

It isto be understood that some of the novel features of the filter arrangement of this pump are covered in my application. Serial No. 381,067, filed concurrently herewith.

Having thus described my invention, what I .claimis: P

'1. In a liquid pump having a plunger barrel with a coaxial outlet port and with an inlet port.

a delivery valve arranged in the outlet port, a

and delivery control and indicating mechanism ior turning said plunger in said barrel and tor indicating the position to which said plunger is delivery valve, a spring extending into said plung- I er and reacting between it and said delivery .valve to effect the suction stroke or said plunger and to draw liquid through the inlet port into said barrel, and control means for controlling the amount oi liquid forced through said delivery valve in the delivery stroke of said plunger.

2. In a liquid pump having a plunger barrel with inlet and outlet ports, a delivery plunger which is reciprocative in said barrel and which has at least a portion or its top surface longitudinally shaped ior cooperation with the inlet port, reciprocating means for reciprocating said plunger to draw liquid through the inlet port into said barrel during its suction stroke and to force liquid from said barrel through the outlet port during its delivery stroke, and delivery control means for turning said plunger in said barrel comprising a lever extending into a slot which is arranged in said plunger and is longitudinally elongated so that said plunger may reciprocate.

' said barrel, a spring extending into the hollow portion of the plunger for effecting its return stroke and to draw liquid through said inlet port into said barrel, and a, lever which extends into said slot and which provides therein a longitudinal clearance to permit said plunger to be reciprocated. without reciprocating said lever.

4. In a liquid pump having a housing with a horizontally elongated slot therein and also having a plunger barrel with inlet and outlet ports, a reciprocative delivery plunger in said barrel having an upper hollow portion with at least a portion of its rim longitudinally shaped for cooperation with the inlet port and also having a solid lower portion with a longitudinally elongated slot therein, operating means for moving said plunger in its delivery stroke to force liquid through the outlet port from said barrel, a spring extending into the hollow portion of the plunger for efiecting its return stroke and to draw liquid through said inlet port into said barrel, and a lever which extends through said slot in the housing and into said slot in the plunger whereby said lever may angularly turn said plunger at any point of reciprocation thereof in said barrel to control a. delivery characteristic of said plunger.

5. In a liquid pump having a housing and also having a plunger barrel with inlet and outlet ports, a delivery plunger which is reciprocative in said barrel and which has at least a portion of its top surface longitudinally shaped for cooperation with theinlet port, reciprocating means for reciprocating said plunger to draw liquid through the inlet port into said barrel during its suction stroke and to force liquid from said barrel through the outlet port during its delivery stroke,

turned.

6. In a liquid pump having a housing with a horizontally elongated slot therein and also having a plunger barrel with inlet and outlet ports, a reciprocative delivery plunger in said barrel having at least a portion of its top surface longitudinally shaped for cooperation with the inlet port and also having a longitudinally elongated slot, reciprocating means for reciprocating said plunger to draw liquid through the inlet port into said barrel during its suction stroke and to force liquid from said barrel through the outletport during its delivery stroke, and delivery control and indicating mechanism comprising -a lever which extends through said slot in the housing and into said slot in the plunger and also comprising an indicating quadrant fixed in said housing and'having an arcuate scale-divided portion which registers with said lever in various positions to which the lever may be turned and which acts to prevent said lever from being disengaged from said slots.

7. In a single cylinder liquid pump having a plunger housing with a barrel having an inlet the same.

8. In a single cylinder liquid pump having a plunger housing with a barrel having an inlet port, a delivery plunger reciprocative in said barrel, a filter housing which surrounds said barrel for at least a part of its length and which has inlet and outlet ports in communication with each other and with the inlet port of said barrel,

- and a stationary filter screen which is'arranged in said filter housing between the ports or said filter housing and the port of said barrel and which extends completely around said barrel, said .pump having means for returning surplus liquid from said barrel through said filter screen to assist in cleaning the same.

9. In a single cylinder liquid pump having a plunger housing with a barrel having oppositely disposed inlet ports, a delivery plunger reciprocative in said barrel, a' filter housing which surrounds said barrel for at least a part/of its length and which has inlet and outlet ports in communication with each other and with the inlet ports of said barrel, and a stationary filter screen arranged in said filter housingbetween the ports of said filter housing and the ports of said barrel, said pump having means for returning surplus liquid from said barrel through said filter screen to assist in cleaning the same.

10. In a single cylinder liquid pump having a plunger housing with a barrel having oppositely disposed inlet ports, a delivery plunger reciprocative in said barrel, a filter housing which is fastened to said plunger housing and around it for at least a .portion of its length and which has inlet and outlet ports in communication with each other, a stationary perforated filter cage arranged between said plunger housing and filter housing, and a cylindrical filter screen covering the perforations therein, said pump having means for returning surplus liquid from said barrel through said filter screen to assist in cleaning the same.

11. In a single cylinder liquid pump having a plunger housing which has a barrel with oppositely disposed inlet .ports and which also has a circular channel around its outer periphery, a filter housing which is fastened to said plunger housing and around it for at least a portion of its length and which has inlet and outlet ports in communication with each other, a stationary cylindrical filter cage which is arranged within said filter housing and which has a plurality of openings around its periphery, and a cylindrical filter screen mounted in said cage, said pump having means for returning surplus liquid from said barrel through said filter screen to assist in cleaning the same.

ciprocative in said barrel; and plunger driving.

means arranged in said compartment and comprising a rotatable shaft, an eccentric fast on said shaft, a ring surrounding said eccentric and operative to lift said plunger, a frictionless bearing interposed between said ring and eccentric, and a spring which during reciprocation of said plunger holds it in contact with said ring, whereby said ring does not rotate with said eccentric. J.- 14. In a liquid pump having a housing with a through bore therein and with an inlet port into said bore; a hollow delivery plunger reciprocative in said bore and having at least a portion of its peripheral rim longitudinally shaped for. cooperation with said inlet port; a delivery valve arranged at one end of said bore; a drive housing fastened to said plunger housing and open to the other end of said bore; plunger driving-means which is, arranged within said drive housin'gand which comprises a rotatable drive shaft, an eccentric fastened on said shaft, a ring operative to lift said plunger in its delivery stroke, and a frictionless bearing interposed between said ring and eccentric; a spring arranged at least in part in the hollow plunger for moving said plunger in its suction stroke and for holding said plunger in contact with said ring; and delivery control and indicating mechanism which is mounted between said plunger and drive housings and which is effective to turn said plunger in said barrel at any point of reciprocation of said plunger therein and to indicate the position to which said plunger is turned.

BEN G. PARSONS.

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