US2368524A

US2368524A - Fuel pump

Info

Publication number: US2368524A
Authority: US
Inventors: Dach Max
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-09-17
Filing date: 1942-09-17
Publication date: 1945-01-30
Anticipated expiration: 1962-01-30

Description

Jan. 30, 1945. M. DACH 2,368,524

FUEL lPUMP Filed Sept. 17, 1942 INVENTOR J/lczoc ,DCL 07?/ JTNESSES Patented Jan. 30, 1945 UNETED STATES PATENT r OFFICE l 2,368,524 e I FUEL PUMP Max Dach, Flushing, N. Y. Application Septemberf17, 1942,y Serial No. 458,658v

` 2 claims. (ci. ros-20s) This invention relates to fuel pumps for inter,- na-l combustion engines,y and more particularly to an improvement therein which may be embodied in the conventional pump or in an attachment therefor.

' It is well known that fuel, such as gasoline, used for internal combustion engines vaporizes readily and quite often vaporization prevents the pump froml operating properly. Excess pressures forming in the line prevent the pump from functioning eiciently, as does vapor accumulating in the pump with no outletJ to escape. i Means have been heretofore provided to relieve excessive v vapor pressures on the pressure side of the pump by meansof attachments. One of the purposes of this invention is to-relieve pressures and vaporization on both sides of the pump, and especially on the suction side of the pump Where they occur as often as on the pressure side.

In the present-day pump vapors are often trapped between the intake and outlet Valves, and it is the purpose of this invention to provide a pump in which the vapors will not be trapped within the pump but will vent themselves through a relief valve o n one side and be transferred either to the carbureter bowl or returned to the tank, and on the other side the vaporsk may vent themselves through the carbureter needle valve.

An object of the invention is therefore to provide a pump in which the areas where vapors are apt to be trapped are so, constructed as to allow the vapors to vent themselves automatically.

A further object is to provide a. more suitable valve which will increase the'eiciency of the pump.

With these and other objects in View, which will become more apparent as the description proceeds, reference is had to the accompanying drawing, in Which- Fig. l is a sectional velevation showing my invention embodied Within a more or less conventional fuel pump;

Fig. 2 is a sectional elevation showing my invention embodiedin an attachment for a conventional fuel pump.

Referring to Fig. l, the pump I is provided with the usual pump chamber II about a diaphragm I2, the outlet valve I3 and inlet valve i4 leading from the filter bowl I5. These partsv operate in the customary manner, invwhich the diaphragm I2 on the down or suction stroke closes the outlet valve, opens the intake valve, and draws fuel from the tank I5 through the line II, passage I8, filter bowl I5, and the intake valve I4. 'The diaphragm I2 is operated by the rocker arm I9 engaging the cam shaft 28. On the pressure stroke the pressure from the diaphragm I2 closes the intake valve I4, opens the outlet valve I3, `and forces the fuel through the line 2| through the carbureter'22.

In the conventional pump diiculty has been experienced with vapors rising from the lter` the passage I8 leading directly into the bowl and construct the head 32 of the bowl with an additional opening 33 leading to the valve 34 positioned by the spring 35.` If the valve 34 is' made of Neoprene, or other material which will not float in gasoline, the spring 35 is not necessary since the valve will automatically seat itself unless the vapor pressures are such as to open it. Above the valve 34 is a restricted passage 36 which leads to the line 31 which may go either to the i carbureter float chamber 38 or back to the tank.

While I have shown the valve 34 as a nat valve in Fig. l, a ball valve (as shown in Fig. 2) made of Neoprene or othersuitable substance, may be used.

It Will be noted that I have eliminated in the pump chamber I I the usual shoulder or boss contained in the conventionalpump, so that the bottom of the passage 21 leading to the outlet valve ls flush with the top of the chamber to enable vapors which may form in the top of the chamber II to pass out through the outlet valve and to be vented by the carbureter needle valve.

As the pump is operated, any vapors or builtup pressurein the area I8 will pass upwardly through the opening 33, and if the fuel is heated considerable pressure is built up to force open the valve 34 to allow the vapors to pass through vthe pipe 31 back to the tank, or to the float chamber of the carbureter.` The valve 34 may be controlled so that no more fuel can escape than the engine consumes at low speed and the restricted passage 36 will accomplish the same result. While theoretically the pump on the suction stroke will cause the intake valve I4 to open and the relief valve 34 to close, and while on the pressure stroke it will cause the valve I4 to close, as a practical matter there is a slight lag between the pressure and suction strokes and a period during which the intake valve remains open until the force of the pressure stroke is sufficient to close it. This sets up a slight back wash in the filter bowl I5, as the result of which there is a point where a certain amount of pressure is exerted against the valve 34 irrespective of whether or not pressure has been built up in the lter bowl by vapors. It follows, therefore, that the valve 34 will open slightly each time the pump changes or has a tendency to do so. In order to insure this action, a slight hole may be drilled in the valve I4 to create an articial back wash.

In the attachment shown in Fig. 2, the housing 50 is provided to screw into the end 5I of the fuel pump I connecting the passageway 53 with the line 54 from the gas tank. An opening 55 leads to the valve seat 56 and a spring-controlled valve 5l, which may be a Neoprene ball or a flat valve, as shown in Fig. 1. An opening 58 is made between the passageway 53 and the filter bowl I5 to allow vapors to pass into the passageway.

Beyond the valve 5'I is a chamber 50 closed by a plug 6I which has an opening B2 connecting with the line 63 leading to the float chamber of the carbureter or back to thetank. The plug 6I has depending walls 64 forming a valve seat 65 at the lower end thereof. As vapors build up pressure in the line or in the filter bowl, the ball 5'I will be pushed upwardly against the seat 65 to allow said vapors to pass into the chamber 60. In the event no pressure is built up, this action will take place on the pressure stroke of the pump. Before the inlet valve I4 is closed on the suction stroke of the pump, the ball 51 will be reseated and the vapors allowed to pass through the passage 62 in the line 63.

It will be appreciated that the form shown in Fig. 2 is adaptable to pumps now in use.

Where the operation of the intake valve is perfect and no back wash occurs in the change from the suction to the pressure stroke, the valve seat may be notched or a small passageway drilled in the pump to create a definite backwash within the lter bowl.

It will be appreciated that slight modications may be made in my device to accommodate it to various types of pumps without departing from my conceptive idea which includes the use of a relief valve to prevent vapors forming in the suction end of the fuel line and to be operated automatically by the action of the pump, and that the pump chamber and lter bowl are so designed that rising vapors will not be trapped by the structure of these elements and may find their way automatically to the pressure outlet valve and to the relief valve.

I claim:

1. The combination with a fuel pump having an inlet and an outlet valve and a filter bowl on'the suction side of said pump with a passage leading to said filter bowl from a feed line, of a supplemental valve between said filter bowl and said feed line communicating with said passage, said valve communicating with a line adapted to carry off vapors forming on the suction side of said pump.

2. A fuel pump comprising a pump chamber, a diaphragm in said chamber, and means for operating said diaphragm, an outlet valve, the bottom of said outlet valve being on a level with the top of said chamber, an inlet valve, a lter bowl communicating with said inlet valve, a`passage leading from the fuel line into said filter bowl, asupplemental opening between said passage and said fuel bowl, and a relief valve positioned between said fuel line and said lter bowl.

MAX DACH.