US2691739A

US2691739A - Reciprocatory electric motor

Info

Publication number: US2691739A
Application number: US344835A
Authority: US
Inventors: Harland L Mchenry; Leland C Parker
Original assignee: Bendix Aviation Corp
Current assignee: Bendix Aviation Corp
Priority date: 1950-12-22
Filing date: 1953-02-04
Publication date: 1954-10-12
Anticipated expiration: 1971-10-12

Description

' 1954 H. a... MOHENRY ETAL RECIPROCATORY ELECTRIC MOTOR Original Filed Dec. 22, 1950 INVENTORSQ (j flaw/ er Patented Oct. 12, 1954 RECITPROCATORY ELECTRIC MOTOR Harland L. McI-lenry, Sayre, Pa, and Leland 0.

Parker, Elmira, N. Y., assignors to Bendix Aviation Corporation, a corporation of Delaware Original application December 22, 1950, Serial No.

202,162, now Patent No. 2,666,153, dated January 12, 1954.

Divided and this application February 4, 1953, Serial No. 344,835

2 Claims.

The present invention relates to a reciprocatory electric motor and more particularly to an electromagnetic device for reciprocating a plunger such as the piston of a fuel pump.

It is an object of the present invention to provide a reciprocation electric motor which is efficient and reliable in operation while being simple and economical in construction.

It is another object to provide such a device which incorporates simple and effective means for controlling the electromagnet.

It is another object to provide such a device in which all the moving parts of the motor are arranged to have rectilinear motion only, and are balanced so as to be unaffected by accelerational forces lateral to their path of movement.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a vertical substantially midsectional view of a preferred embodiment of the invention showing the parts in idle position;

Fig. 2 is a fragmentary section showing the parts in the positions assumed when the piston approaches the lower end of its stroke;

Fig 3. is a view similar to Fig. 2 showing the parts in the positions assumed when the piston starts up on its discharge stroke.

In Fig. 1 of the drawing there is illustrated a cylinder l of non-magnetic material in which is slidably mounted a hollow plunger 2 of magnetic material such as soft iron. The upper position of plunger 2 is defined by a cylindrical stop 3 of suitable material such as fiber. A spring 4 urges the piston upward toward said stop, and means for overcoming the spring and drawing the piston downward is provided in the form of a solenoid 5. Circular pole pieces 6 and i are located at the ends of the cylinder and serve to locate the solenoid and the cylinder l within a cylindrical housing 8 of magnetic material which serves to complete the external magnetic circuit of the solenoid.

Means for energizing the solenoid 5 is provided comprising a battery 9 which is grounded at H and connected through a switch i2 and a lead 13 to a contact M mounted on a resilient blade [5 attached to but insulated from the cas ing 8 as indicated at It. A second contact ll adapted to cooperate with the contact Hi is connected by a lead it to one terminal of the solenoid, the opposite terminal of which is grounded at l9 to complete the electrical circuit. Means for controlling the contacts I4, I! is provided comprising an electro-magnet H which is slidably mounted on the exterior of the cylinder i. One terminal of the electro-magnet 2i is connected by a lead 22 to the battery lead 83 and the other terminal is grounded as shown at 23 so that the electro-magnet is energized continuously as long as the switch 82 is closed.

Electro-magnet 2! is provided with a casing 24 of magnetic material which serves to oomplete the external magnetic circuit thereof, and is urged upwardly by a spring 25 so as to cause said casing toengage the free end of the blade 15' and move the contact Hi out of engagement with the contact I1. The parts are so arranged that when they are in idle position as shown in Fig. l, the plunger 2 has entered part way into the electro-magnet 2i whereby energization of the electro-magnet will attempt to draw the plunger upward, and since this movement of the plunger is prevented by the stop 3, the electro-magnet will move downward so as to allow contacts Hi, I"! to close.

In the operation of this embodiment of the invention, starting with the parts in the position shown in Fig. 1, closure of the switch 82 causes energization of the electro-magnet 2! which thereupon moves downward against the force of the spring 25, and permits contacts i l, I! to close. The consequent energization of the solenoid 5 causes the plunger 2 to move downward as shown in Fig. 2, drawing the electromagnet 28 with it until the electro-magnet is arrested by the spring 25. This spring then becomes effective to return the electro-magnet to its upper position as shown in Fig. 3, opening the contacts l4, ll. The consequent deenergization of the solenoid 5 permits the spring A to move the plunger 2 upwardly until it enters the elec tro-magnet 2i sufficiently to again cause the electro-magnet to move down and close contacts Hi, i? whereupon the operation is repeated.

In order to utilize this motor as a pump, the casing 8 is provided with an inlet 26 and an outlet 21, and chuck valves 28 and 29 are mounted in the lower end of the cylinder I and the upper end of the plunger '2 respectively.

This is a division of application Ser. No. 202,162, filed December 22, 1950, now Patent No. 2,666,153, January 12, 1954.

Although certain structural features of the invention are shown and described in detail, it will be understood that other embodiments are possible and that various changes may be made in [the design and arrangement of the parts without departing from the spirit of the invention.

We claim:

1. In a reciprocating electromagnetic motor a solenoid, a non-magnetic hollow cylinder fixed in the solenoid and projecting therefrom, a piston of magnetic material slidably mounted in the cylinder, an abutment limiting the projection of the piston from the solenoid and thus defining its idle position, a spring urging the piston toward idle position and cocked by the movement of the piston responsive to energization of the solenoid, a cylindrical casing of magnetic material surrounding the solenoid, annular pole pieces of magnetic material at the ends of the solenoid supporting the solenoid in the casing and providing with the casing a path of low reluctance for the portion of its flux circuit external to the solenoid, an annular magnet on the projecting portion of the cylinder, surrounding the projecting end of the piston and movable therewith by mutual attraction; means for energizing the solenoid including a pair of contacts biased toward closed position, means responsive to movement of the magnet away from the solenoid for opening said contacts and a spring operative at the end of the cocking stroke of the piston to overcome the mutual attraction of the magnet and piston and move the magnet to open the contacts and thereby deenergize the solenoid.

2. An electromagnetic motor as set forth in claim 1 in which the magnet is in the form of a ring surrounding the cylinder with poles arranged axially of the cylinder, said abutment for the piston being so located that the end of the piston is within the magnet when the magnet isholding the contacts open.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,640,742 Wallace et a1 Aug. 30, 1927 1,903,902 McLaren Apr. 18, 1933 2,468,343 Parker Apr. 26, 1949 2,472,067 Dickey June '7, 1949 2,472,334. McHenry June 7,v 1949