US1902930A

US1902930A - Fuel pump

Info

Publication number: US1902930A
Application number: US260419A
Authority: US
Inventors: Zubaty Joseph
Original assignee: Individual
Current assignee: Individual
Priority date: 1928-03-09
Filing date: 1928-03-09
Publication date: 1933-03-28
Anticipated expiration: 1950-03-28

Description

March 28,1933. J. ZUBA TYQ 1,902, 30

FUEL PUMP Filed Mrch 9.192s

' dual/w 30 of Figure Patented' Mar. 28, 1933 UNITED STATES Josnin ZUIBFATY, or FLINT, :nncmem FUEL ruin],-

: Application filed.ll[arch 9,

Thisinvention is concerned with the fuel supply for an internal combustion engine and particularly for an engine employing a supercharger and one wherein the fuel is supplied to the carburetor by an engine operated fuel An object of the invention is to provide an improved fuel pump for use with an internal combustion engine having associated therewith a supercharger placed beforethe carburetor and compressing air only. More specifically, the invention provides a pump having a discharge stroke the efliciency of which is made variable and whichefliciency is automatically. changed to supply fuel to the carburetor at a pressure dependent upon the air pressure delivered to the carburetor by the supercharger. Other objects and advantages will be understood from the following description and from an examination of the accompanying drawing.

In the drawing: Figure 1 is a side'elevation of an internal combustion engine, such as is used on mo-" tor vehicles, the engine having my improvements associated. therewith.

Figure 2is a vertical. section through parts of the fuel supply system. c

Figure 3 is a horizontal section on line 33 Referring by reference characters to'the drawing, numeral 5 is used to designate an internal combustion engine. The invention is concerned only with the fuel system for the .35 engine and other parts will not be included in this description. Numeral7 is usedto,

designate an intake manifold and 9 a header therefor connected to a carburetor 11 by fastening means 13.

An-air cleaner 15 of any preferred kind maybe used. If such an air cleaner is used, it will be connected to a supercharger 17 for delivering air to. the carburetor. The structure of this supercharger need not be de- 4 scribed as the details of'the supercharger are.

matter ofthis invention is used in connection 1928. Serial No. 260,419.

no part of this invention. The supercharger draws air through the cleaner 15, if such cleaner is used, and deliversthe air at superatmospheric pressure to the air inlet tube 23 of the carburetor 11, the air under high pressure passing through the header 9, manifold 7 and into the engine cylinders.

In such a system, the pressure in the ven-; turi of the carburetor may become sufficient, 1y high to oppose the flow of fuel from the float chamber. This difiiculty is remedied by I sealing the float chamber 21 and connecting the. sealed float chamber with the air tube 23 of the carburetor by asuitable conduit 19 as shown in Figure 1. This provision as-.

sures an ample fuel flow even when the-pressure in tube 23 is above atmospheric.

Numeral 25 represents a fuel pump having a diaphragm 27 confined between body 29 and its cover 31. The cover 31 is preferably ex- 05 tended beyond the pump body and to the extension may be secured a filter cup 33.. A

bail 35 is attached to the cover'extension and surrounds the cup 33. A screw eye 37 hasits eye portion encircling the bail beneath the cup 33 and an adjusting nut 39 may be threaded up on the threaded part of the l screw "eye to hold firmly against theb'ottom of the cup a support 41 This is described as a convenient and preferred form of cup support but'these details do not form a part of this invention.

The cover 31 has an inlet 43 communicating with the fuel-reservoir. 'When the subject with motor "vehicles, the fuel reservoir willobviously be the tank usually carried in a low position at the rear of the vehicle. From the inlet 43 and angular passage 45 conducts the fuel to an opening or openings 47 communicating with the interior of the fuel cup and beneath suitable filtering. means 49.

Filtered by said filtering means, the fuel may pass an inlet valve designated by numeral 51 and preferably located in the cover mem- 90 ber. From valve 51 the fuel passes through passage 53 to the variable volume pm chamber of the pump 25. This chamber is constituted by the flexible diaphragm 27 and the outer 31. An outlet valve 55 of any preferred form is also located preferably in the cover member 31 and controls a discharge from the pump chamber to the pipe 57 leading to the float chamber of the carburetor.

The diaphragm'27 is reinforced by discs 59 and connected by a rod 61 with a collapsible link member 63 to be connected to suitable operating means. This operating means may be of some other type but is preferably in the form of a lever pivoted to the pump body, one end of the lever engagingtheblower end of the collapsible link and the other end of the link actuated by-the cam of the camshaft. This construction is not illustrated as it is well-known and constitutes no part of this invention. By this arrangement, the operating means may through the. instrumentality of the collapsible link, pull down upon the diaphragm to make a suction stroke. The.

discharge stroke is preferably made by a coil spring 65 engaging the lower disc 59 and also an abutment in the pump body. In the usual use of such a pump where no supercharger is employed, the lower abutment for spring 65 is fixed. In the present form, however, an automatically variable lower abutment is made use of as described below. In use, the

collapsible link pulls down upon the diachamber sealed and under super-atmospheric pressure, the discharge operating spring 65 of pump 25 may not be sufliciently effective to overcome the pressure in the float chamber which the pumpsupplies. This inventionhasb 11 made to correct this difficulty by givi g to spring 6'5 added efficiency in proportion to the added burden to which it may be subjected. To this end instead .of providing a fixed abutment beneath spring 65, there is a variable abutment. A lower" disc 67 has an upper cam surface en aging a similar cam surface on the lower ace of an upper cam disc'69. The spring rests on the up er disc '69. Means are provided to rotate isc 69 on' disc '67'to thereby raise the lower spring abutment and add to its effective pressure in producing the discharge stroke of the pump. Toaccomplish' this purposev the upperdisc is provided with a radial nected to tone end of link 73. I The cover 77 is provided with an opening 91 to which is secured the end of a conduit 93, which also communicates with the airtube 23 of the carburetor. By this means, the air pressure in the air tube 23 is communicated to the chamber defined by cover 77 and diaphragm 81. One or more breather-openings 95 are provided in the chamber 75 to keep the air therein at atmospheric pressure and'make possible a flexing of the diaphragm 81 with changing pressures in the air tube of the carburetor. A spring 97 is placed on the atmospheric side of diaphragm 81 to return the diaphragm to its former position after being moved inlwardly by air pressure. It will be under stood that such inward movement recipro cates plunger 83'and link 73 and rocks disc 69 upon disc 67 whereupon the cam surfaces cause. the rising of the lower abutment of spring 65. As a result spring 65 is rendered more effective in overcoming the fluid pressure in the pump chamber and thereby more effective in dischargingffuel from the pump to the sealed float chamber of the carburetor.

'It will be understood that simultaneously with increased ressure in the float chamber due to pipe 19 t e pressure on diaphragm 81 is increased and spring 65 is given additional efficiency to deliver fuel to the carburetor.

While but one mechanical connection between the lower spring abutment and the control chamber 75 is herein described, it will beof course understood that other connections to accomplish the same result may be resorted to. A double arm lever, for examle, might'be pivoted to the pump chamber avingone arm actuated by the connected link 73,and the other operable to raise the movable abutment for spring 65. Numerous 4 other expedients will be obvious.

By the arrangement described, there is pro vided a fuel pump operable by resilient means on its discharge stroke and which resilient means is rendered automatically va riably efi' ective in proportion to the Variable need for a discharge stroke dependent upon the pressure in a sealed float chamber. The result is accomplished by'means both simple and inexpensive.

Iclaim:

1. In a. fuel supply system for internal combustion engines, a carburetor having a sealed float chamber. 'nd an .air inlet, a su- "percharger delivering air ugler pressure to said air inlet, a condu'it from said air inlet to said float chamber, a pump having ayielding member to effect a discharge stroke, a

movable abutment therefor, a variable vollune chamber, a conduit therefrom to said air inlet, a plunger reciprocable by air pressure in said chamber, said plunger operably connected to said variable abutment whereby the potential energy of the yielding member is modified by movements of the plunger.

2. The invention defined by claim 1, said movable abutment comprising amovable cam member, a fixed cam member in engagement therewith, the first-named cam member serving as an abutment for the yielding member.

3. The invention defined by claim 1, said movable abutment comprising a rotatable disc having a cam face, a fixed disc having a co-operating cam face, said first-named disc serving as an abutment for said yielding member and provided with an arm, said plunger connected to said arm.

4. In a fuel supply system for internal combustion engines, a carburetor having a sealed float chamber and an air inlet, a super- 1 charger delivering air under pressure to said air inlet, a conduit from said air inlet to said float chamber, a variable stroke pum delivering fuel to saidfloat chamber, sai pump comprising a collapsible linkage to effect the suction stroke and a sprin to effect the dis charge stroke whereby tfie length of the stroke is dependent on the pressure in the float chamber, amovable abutment for said spring to var the pressure exerted thereby during the dlscharge stroke, and means to v automatically control the position of said abutment by the air pressure in the carburetor air inlet.

5. In a fuel supply system for internal combustion engines, a carburetor having a sealed float chamber and an air inlet, a superchargerrdelivering air under pressure to said air inlet, a conduit from said air inlet to said float chamber, a variable stroke pump delivering fuel to said float chamber, said pump comprising lost motion means to effect the suction stroke and yieldin means to effect the discharge stroke where y the length of the stroke is dependent on the pressure in the float chamber,'a movable abutment for said yielding means to vary the pressure exerted thereby during the discharge stroke,

and means to automatically control the position of said abutment by the air pressure in thecarburetor'air inlet.

6. In a fuel supply system for internal combustion engines, a carburetor having a sealed float chamber and an air inlet, means to supply air under pressure to said air inlet, a conduit from said inlet to said float chamher, a fuel pump, a conduit from said pump to said float chamber, said pump having yielding means as the sole agency to efiect a plunger operably connected to said movable abutment.

In testimony whereof I aflix my signature.

JOSEPH ZUBATY.