US2084605A - Electric fuel pump - Google Patents

Description

June 22, 1937. E. F. WEBB 5 ELECTRIQ FUEL PUMP Original Filed. 001:. 28, 1933 .57 so WWI I; 8 7 56 as 1 15.3.

36 v 11 30 a4 3% 2.5:; Q 2, n 38* 1/20 as 42 -i I' III INVENTOR. EDMOND E WEBB.

Patented June 22, 1937 UNITED STATES PATENT OFFHCE ELECTRIC FUEL PUMP Edmond F. Webb, Royal Oak, Mich., assignor to Chrysler Corporation, Detroit, Mich., a corporation of Delaware 5 Claims.

This invention relates to an improved fuel pumping system for internal 'combustion engines and particularly to an electrically energized device of this character.

The main objects of the invention are to provide an electric fuel pumping system. for feeding fuels under pressure from a fuel tank to the carburetor or other fuel delivery means of an internal combustion engine; to provide a magnetically operable pump unit in a system of this kind having a solenoid circuit which extends into the fuel tank; to provide a circuit of this kind which has completely closed portions extending into the fuel tank and located in the vicinity thereof, said completely closed portions being absolutely devoid of make and break devices and other spark forming element; to provide a pump unit which may be safely located in the fuel tank where it is free from vapor lock which occurs when the fuel pump is mounted in close prox imity to an engine and subjected to the heat radiated therefrom, without the hazard of ignition of fuel or fuel vapor in or around the tank; and

to provide a device at a remote location from the 7 fuel tank for intermittently energizing the solenoid of the pump unit.

Other objects of the invention are to provide an improved device for intermittently energizing the solenoid of an electric fuel pumping unit; to provide a device of this character which may be constructed and arranged to be operated by any conventionally located rotative part of an engine, such as the crank shaft, the cam shaft or distributor shaft thereof; to provide a commutator which is adapted to cause the fuel displacing element of the pump unit to perform more strokes per revolution of the commutator rotor at cranking speed of the engine than during idling operation thereof, and substantially fewer strokes 40 per revolution of the commutator rotor during operation of the engine at normal running speeds; and to provide a device of this character which Will deliver a greater quantity of fuel per revolution of an. engine crank shaft during en- 45 gine cranking operations than during normal running operations.

An illustrative embodiment of the invention is shown in the accompanying drawing, wherein:

Fig. l is a diagrammatic end elevational view of an engine, and a side elevational view of a fuel tank equipped with my improved electric fuel pumping system.

Fig. 2 is an enlarged transverse section of the fuel pumping unit taken on the line lI-II of 55 Fig. 1.

Fig. 3 is a transverse sectional view taken on the line IIIIII of Fig. 1, and illustrating somewhat diagrammatically the commutator stator and rotor of the improved fuel pumping system.

Fig. 4 is a transverse sectional view of the pumping unit taken on the line IVIV of Fig. 2.

In the form shown, the improved fuel supplying system includes a pumping unit It) which is disposed in a fuel tank l! of the type conventionally provided on motor vehicles, and located 10 at the rear end thereof. The pumping unit includes a tubuluar member l2 which is provided at its upper end with a frusto-conical portion l3 having a radial flange I4 disposed between gaskets I5 mounted on the top surface of the fuel 15 tank I! and surrounding an opening it in the latter. The lower end of the tubular member l2 is also provided with a frusto-conical portion having a radialflange E8 to which a cylindrical casing is attached by bolts 2|. The casing 20 20 includes a lower cup shaped element 22 having a disc 23 disposed over its open extremity, the disc 23 and cup shaped section 22 being secured together by the bolts 2|. A gasket 24 is provided between the. radial flange |8 of the tubular mem- 25 her l2 and the disc 23 and a gasket 25 is disposed between the latter disc and the cup shaped section 22 of the casing 20 for forming liquid tight seals between the convenable parts of the structure. A valve housing 26 having an inlet opening 21 is secured to the lower extremity of the cylindrical casing 28 by the bolts 2|.

Concentrically located in. the cylindrical casing 20 is a cylinder comprising a metal sleeve 28 having an opening 29 in its upper extremity surrounded by an inwardly extending flange 39. The lower end of the cylinder 28 is provided with an opening 3| which communicates with the inlet opening 21 of the valve housing 26 through a plurality of passages 32 formed in the lower wall of the cup shaped section 22 of the casing 20. The inlet opening 21 of the valve housing 26 is normally closed by a disc valve 33 which is yieldably held upon its seat by a coil spring 3 bearing between the disc valve and the lower extremity of the cup shaped section 22 of the casing 29.

Reciprocably mounted in the cylinder 28 is a piston 35 which preferably comprises iron or other magnetically attractable metal. The piston 35 has a substantially hollow interior and it 5 is provided with a head portion 36 having outlet apertures 31. The outlet apertures 3 communicate with the interior of the piston and with an inlet opening 38 to the interior of the piston which is normally closed by a disc valve 39. The

disc valve as is yieldably held upon its seat by a spring 4E bearing between the valve and the internal side of the head 35 of the piston.

A spring ti normally urges and yieldably holds the piston 35 at the upper end of the cylinder 28, and a solenoid d2 surrounding the cylinder 28 and located between the latter and the peripheral wall of the casing 2c is provided for intermittently urging the piston 35 downwardly against the action of the spring ti. Each upward stroke of the piston 35 opens the valve 33 and draws fuel into the interior of the cylinder 28, and each downward stroke of the piston forces the fuel trapped between the latter and the valve 33 upwardly through the opening 38 past the valve 3% and through the outlet apertures 3?. Fuel is in this manner delivered under pressure-to the tubular member l2 from which it is conveyed by a conduit 55 to the fuel reservoir 63 of a carburetor i i which is included in the fuel mixture supply system 38 of an internal combustion engine 59. The rear end of the conduit Ell is provided with a fitting M which is threaded in an opening 52 of a disc shaped cap 53 disposed over the opening it in the fuel tank, and normally secured to the latter by bolts 56.

The solenoid i2 is electrically connected in a circuit 55 leading from the solenoid to suitable make and break apparatus by which the solenoid is intermittently energized. The circuit 55 includes a pair of lead wires 56 and 5'! which are integrally connected with the Winding of the solenoid and permanently secured to terminals 58 and 59 mounted on the cap 53 and electrically insulated therefrom by insulating sleeves iii and ti. The portion of the circuit 55 which is disposed in the tank and the portions thereof located in the vicinity of the tank are permanently closed. One terminal of a battery 62, or other source of power, is directly connected to the terminal 58 of the pump unit, and the other ter minal of the battery is directly connected with the make and break apparatus. The ternunal 58 of the pump unit is also connected to the make and break apparatus.

The made and break apparatus illustrated in the drawing includes a commutator having a stator 63 and a rotor 64. The rotor may be driven by any conventionally accessible rotative part of the engine ll but it is preferably operatively connected with some member of the engine which rotates either in unison with the engine crank shaft or at some speed proportional to the speed of rotation of the engine crank shaft.

One operative connection between the crank shaft of the engine and the rotor 64 of the commutator is illustrated in Fig. 1, wherein the engine crank shaft 55 is provided with a pinion 66 which is connected by a chain all with a gear 78 mounted on the engine timing shaft l9. A pinion secured to the timing shaft is is meshed with a Worm gear 8% carried by the distributor shaft 82 of the engine. The shaft 82 operates the conventional distributor mechanism of the engine ignition system and also operates the rotor E i of the commutator of the fuel pumping system in timed relation to the crank shaft. The rotor of this commutator may, it is recognized, be driven by any rotative part of the engine. For the purpose of convenience of illustration, and in order to disclose one economical manner for operating the commutator rotor, the latter has been combined With the distributor so that the rotor of the distributor and the rotor of the commutator may be driven by the same shaft.

The rotor 64 of the commutator is provided with a contact element 83 which is adapted to successively engage a plurality of circumferentially arranged contact elements formed on the stator 63. The stator may be provided with any desired number of contact elements which are preferably asymmetrically arranged and of dif ferent lengths, the construction and arrangement of the contact elements of the stator being such that at low speed rotation of the rotor it the solenoid d2 will be energized throughout a greater number of periods of sufficient duration to cause the piston to perform more strokes per rotation of the rotor than during high speed operation of the latter. In the form shown, this is accomplished by providing the stator with three relatively long contact elements which are located in close proximity to each other, and three comparatively short contact elements 85 which are circumferentially spaced at greater distances apart. The exposed portions of the contact elements are separated from each other by suitable dielectric material. The relative lengths of the contact members and the distances therebetween are preferably predetermined so that, during rotation of the rotor at cranking speeds of the engine, each contact element will cause the solenoid d2 to be energized long enough to permit the pis ton to be moved to the lower end portion of the cylinder 28 and to thereafter be projected up- Wardly so as to perform one complete discharge stroke for each contact element of the rotor. The construction and arrangement of the contact elements of the stator is such that at idling speeds of the engine, the three closely adjacent contact elements fi l will produce only one effective stroke ofthe piston and each contact element will cause the piston to perform one partial stroke respectively. At normal running speeds of the engine, however, only one stroke of the piston is produced during each rotation of the rotor 54, for the periods of energization occurring while the contact 83 of the rotor is in engagement with the short contacts 85 of the stator are of insufficient duration to permit the solenoid to overcome the action of the spring il and the inertia of the piston, and, therefore, the piston is not moved from its uppermost position shown in Fig. 2. The duration of the periods of interruption of energization of the solenoid brought about by the dielectric material E6 between the relatively long contacts 34 is insuflicient to permit the spring ii to urge the piston 35 upwardly, as contact between the element 83 of the rotor and successive elements 8d of the stator is broken, and therefore the piston remains in its lowermost position substantially from the time the contact 83 engages the first of the series of three contact elements 84 until the contact element 83 becomes disengaged from the last of said series of contact elements. In operation of the engine at its normal running speed, only one effective pumping stroke of the piston occurs, while during operation of the engine at cranking speeds six substantially full strokes of the piston take place. At idling speeds three substantially full strokes and three partial strokes of the piston occur. In this manner the system is conditioned to supply the required amount of fuel to the carburetor at the diverse speeds at which it is operated.

By locating the pump unit in the fuel tank which is conventionally disposed remote from the engine and engine compartment of a vehicle,

vapor locking of the pump unit is effectively guarded against. This can be accomplished with the improved vehicle pumping system without the accompanying hazard of fire or explosion resulting from ignition of the fuel or fuel vapor in or around the tank, for all portions of the solenoid circuit located in the tank and all those portions thereof located in the vicinity of the tank are permanently closed. The make and break apparatus is safely located in the engine compartment of the vehicle at a considerable distance from the fuel tank so that there is no danger of ignition of the fuel by the sparks or arcs which may occur during engagement and disengagement of the contacts of the rotor with the contacts of the stator of the commutator.

Although but one specific embodiment of the invention is herein shown and described, it will be understood that various changes in the size, shape, and arrangement of parts may be made without departing from the spirit of my invention, and it is not my intention to limit its scope other than by the terms of the appended claims.

What I claim is:

1. In a vehicle having an internal combustion engine provided with a fuel system including fuel feeding means adjacent said engine and a fuel supply tank remote therefrom; apparatus for supplying fuel under pressure from said fuel tank to said fuel feeding means including a pump unit in said fuel tank having a magnetically op erable fuel displacing element and an electromagnetic member for operating said element, a commutator remote from said fuel tank having a stator member and having a rotor member operatively connected with a rotative part of said engine, one of said members having a plurality of contact elements for engaging the other member, some of said contact elements being of different lengths and asymmetrically arranged to cause said fuel displacing element to perform one effective stroke per contact element during each revolution of said rotor member at cranking speeds of said-engine and to cause said fuel dis placing element to perform less than one effective stroke per contact element during each revolution of said rotor member at normal running speeds of said engine, and a circuit including a source of electric power and connecting said electro-magnetic member and said contact elements, all portions of said circuit within said fuel tank and in the vicinity thereof being permanently closed.

2. In a vehicle having an internal combustion engine provided with a fuel system including fuel feeding means adjacent said engine and a fuel supply tank remote therefrom; apparatus for supplying fuel under pressure from said fuel tank to said fuel feeding means including a pump unit in said fuel tank having a magnetically operable fuel displacing element and a solenoid for operating said element, a commutator having a stator member and having a rotor member operatively connected with a rotative part of said engine, one of said members having a plurality of contact elements for engaging the other member, some of said contact elements being of different lengths and asymmetrically arranged to cause said fuel displacing element to perform one substantially full stroke per contact element during each revolution of said rotor member at cranking speeds of said engine and less than one full stroke per contact element during each revolution of said rotor member at idling speeds of said engine and only one effective stroke per contact element during each revolution of said rotor at normal running speeds of said engine, and a circuit including a source of electric power and connecting said solenoid and said contact elements.

3. In an internal combustion engine; a pumping apparatus including a receptacle, a magnetically operable fluid displacing element in said receptacle, resilient means for normally urging said element in one direction, a solenoid for moving said element in an opposite direction against the action of said means, and a commutator including a stator member and a rotor member, means for driving said rotor member in timed relation with said engine, one of said members having a set of widely spaced comparatively short contact elements and a second set of relatively longer contact elements disposed in close proximity to each other, said contact elements being constructed and arranged to cause said fluid displacing element to perform one stroke per contact element during each rotation of said stator at a speed within a predetermined range and to cause said fluid displacing element to perform less than one stroke per contact element during each rotation of said rotor at speeds above said predetermined range.

4. In an internal combustion engine; a pumping apparatus including a receptacle, a magnetically operable fuel displacing element in said receptacle, means for operating said element including an electro-magnetic member, means for driving said rotor member in timed relation with said engine, a commutator including a stator member and a rotor member, one of said members having a set of widely spaced comparatively short contact elements and a second set of relatively longer contact elements disposed in close proximity to each other, said contact elements being so constructed and arranged as to establish a higher ratio of strokes per contact element at low speed operation of said rotor member than at operation thereof at normal running speeds.

5. In an internal combustion engine, a pumping apparatus including a receptacle, a magnetically operable fuel displacing element in said receptacle, means for operating said element including an electro-magnetic member, a commutator including a stator member and a rotor member, means for driving said rotor member in timed relation with said engine, one of said members having contact elements thereon and some of said contact elements being of different effective lengths and being asymmetrically arranged so as to establish a higher ratio of strokes of said fuel displacing element per contact element during low speed operation of said rotor member than during operation thereof at normal running speeds,

EDMOND F. WEBB.

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