US3431859A - Electromagnetic pump - Google Patents

Description

March 11, 1969 R. LE FLEM 3,431,859

ELECTROMAGNETI C PUMP Filed May 24, 1967 Pics/1 33 United States Patent Ofice 3,431,859 Patented Mar. 11, 1969 US. Cl. 103-53 2 Claims Int. Cl. F04b 17/04, 45/02 ABSTRACT OF THE DISCLOSURE An electromagnetic pump in which a coil and its core are disposed in a deformable casing which in turn is placed in a chamber provided with a suction valve and a delivery valve, said casing includes a bottom with which the plunger core of the electromagnetic coil is integral. The core of the electromagnet includes, on the one hand, at one of its ends, a magnetic body, one face of which lies opposite a corresponding body or counterpart, said face being provided with an inner conical recess tapering at an angle of from 40 to 50 which is the same as the conical end portion of said corresponding body, and, on the other hand, a support for one of the contacts of a switch, and for a rocker supporting the other contact of the switch and adapted to be rocked and locked in either of its two positions by a spring strip integral with pump cylinder. The cylinder includes moreover a housing in the front surface thereof in which a filter is placed between the suction and delivery valves.

The present invention relates to an electromagnetic pump adapted to have manifold applications, but more particularly intended for feeding fuel to carburetors for internal combustion engines. This is, as a matter of fact, a particular application in which the advantages of electric pumps over conventional mechanical pumps provided with diaphragms are well known, to wit, instantaneous feeding of the carburetor as soon as the general electric circuit is closed, no connections being needed between the mechanical members of the motor and the pump, etc. It should be noted, however, that the above-mentioned application is given by way of example, and that the scope of the invention is not limited thereto.

The pump of the invention is of the electromagnetic type including a coil fed by the electric circuit of the vehicle, and a plunger core shifted in the return direction by the action of a spring, and in the outward direction by the attraction exerted by said coil when, at the end of the return travel of said core, the latter closes a contact located in the above-mentioned circuit, the travels of said core giving rise to capacitance variations in a chamber provided with a suction valve and a delivery valve.

The pump of the invention is more particularly of the type in which the coil and its core are housed in a deformable casing which is in turn disposed in a chamber provided with a suction valve and a delivery valve, said casing including a bottom with which the plunger core of the electromagnetic coil is integral.

The pump of the invention is characterized in that the core of the electromagnet causing the shifting of the deformable diaphragm includes, on the one hand, at one of its ends a magnetic body, one face of which lies opposite a corresponding body or counterpart, said face being provided wtih an inner conical recess tapering according to the same angle as the conical end portion of said counterpart, said angle being from 40 to 50, and, on the other hand, the support for one of the fingers of the breaker, which support is keyed on the other end of said core,

while a rocker is hinged on said support, said rocker supporting the other finger of the breaker and being adapted to be rocked and locked in its two positions by a spring strip integral with the pump cylinder, said cylinder including moreover a housing in the front surface thereof, a filter and a double suction and delivery valve being disposed in said housing.

The invention will now be explained in further detail in the following description, with reference to the appended diagrammatic drawing which illustrates, by way of non-limiting example, an embodiment of the electromagnetic pump of the invention. In said drawing:

FIGURES 1 and 2 are longitudinal sectional views of said pump, at the end of the return stroke and at the end of the forward stroke, respectively.

A diaphragm 20 of the pump is integral with a plunger core 22 of an electromagnet provided with a magnetic body 23 which is secured at the end of said core. Said electromagnet includes moreover a frame 24, a coil 25 and a counterpart 26, that is, a body corresponding to the body 23, said frame, said coil, and said counterpart being coaxial to the core 22 which is slidingly mounted inside the counterpart 26. Said electromagnet is secured to the cover 4 by means of a shouldered internal screw 27.

The surface of the body 23 opposite the counterpart body 26 is provided with a recess 28 the conical wall 28a of which slopes at the same angle of from 40 to 50 as the conical end portion 26a of said body 26. This arrangement reduces the gap between the body 23 and its counterpart 26, and the travel of the core 22, while giving to the electromagnet a greater attractive force, so that, with an equal mass, said electromagnet has an attractive force much greater than that of a conventional electro-magnet.

An insulating support 29 is secured on the portion of the core 22 lying outside the chamber 3 of the pump. One contact 30 of the switch is secured on said support 29, to which is pivoted on a pin 32 a rocker 34 carrying the other contact 35 of the switch.

Said rocker includes a heel 34a on which bears a spring strip 36 secured to the screw 27.

The cylinder 2 of the pump includes a housing in which a filter 37 and a double valve are disposed. Said double valve includes two bodies 38a, 38b, which are fitted into each other and provided respectively with a suction valve 39a and a delivery valve 39b. Said valves are normally held on their fiat seats by their own weight but are adapted to shift between said seats and stop rings 40 located in corresponding grooves.

With the pump in the position shown in FIGURE 1, when the supply circuit represented by the leads 42 is closed, the coil 25 becomes energized and causes shifting of the core 22 until the magnetic body 23 is in contact with the corresponding body 26, against the opposing force of a spring 43 disposed between the bottom 20 of the diaphragm and the frame 24 of said coil 25.

Said shifting of the core 22 creates a lowering of pressure in chamber 3, which lowering of pressure causes thevalve 39a to be lifted, the valve 39b to close, and the liquid to flow into said chamber 3 through the port 33.

The core 22, while moving, carries the support 29 and the rocker 34, the heel 34a of which, by hearing on the spring strip 36, causes said rocker to rock in the direction of the arrow 44 in FIGURE 2. Such rocking moves the two contacts 30, 35, of the breaker away from each other and thus cuts off the supply to the coil 25. Under the action of the spring 43, the diaphragm comes back to its initial position, while driving out through the port 33 the liquid contained in the chamber 3, which liquid then flows through the valve 39b, which is lifted, and finally through the duct 45. Simultaneously, the core 22 moves and causes the rocker of the switch to rock again, so that the circuit is closed again and the cycle starts again. It should be noted that the rocker 34 is locked automatically in its open position and in its closed position by the spring strip 36 acting on the heel 34a of said rocker.

Owing to the arrangement described, the operation of the pump of the invention is particularly sa-fe, while the opening and the closing of the supply circuit by the switch are very sharp.

According to the provisions of the patent statutes, I have described the principle of my invention and have described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What I claim is:

1. An electromagnetic pump comprising means defining first and second separated chambers having a communicating aperture therebetween, a suction valve and a delivery valve in the first chamber on opposite sides of said aperture, a filter between the suction valve and a fluid inlet provided in said first chamber, a displaceable diaphragm in said second chamber, an electromagnet in said second chamber for displacing the diaphragm between first and second positions, said electromagnet including a body fixedly mounted in the second chamber, a coil wound on said body, a plunger slidably mounted in said body and secured to said diaphragm, and a magnetic member secured to said plunger and facing said coil to be attracted thereto when the coil is energized thereby to displace the diaphragm to said first position, spring means acting on said diaphragm to urge the same to said second position when the coil is deenergized, said magnetic member having a recess facing said body for receiving said body therein when the diaphragm is in said first position, said recess having a conical taper with an angle between 40 and 50, said body having a corresponding taper, switch means on said plunger for controlling energization of said electromagnet, said switch means including a support secured to said plunger, a contact fixedly mounted on said support, a rocker pivotably mounted on said support, a second contact secured to said rocker, and a spring strip secured in said second chamber in the path of the rocker for pivotably moving the same to a position in which the contacts are closed when the diaphragm is in said second position, and to a position in which the contacts are opened when the diaphragm is in said first position whereby the diaphragm is caused to undergo reciprocal movement in said second chamber, under the action of the electromagnet, and produce suction in the first chamber in one stroke and consequent introduction of the fluid into the first chamber through the filter and the now opened suction valve, and produce pressure in the first chamber in the opposite stroke to deliver the fluid through the now opened delivery valve.

2. A pump as claimed in claim 1, wherein said valves are coaxial and said filter extends axially thereof.

References Cited UNITED STATES PATENTS 1,346,555 7/1920 Reeves l0353 1,987,257 1/1935 Kent et a1 103-53 FOREIGN PATENTS 273,576 4/1930 Italy ROBERT M. WALKER, Primary Examiner.

US. Cl. X.R. 310-18

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