US2941056A

US2941056A - Momentary contact switch

Info

Publication number: US2941056A
Application number: US769253A
Authority: US
Inventors: Kenneth R Wallace
Original assignee: Essex Wire Corp
Current assignee: Essex Wire Corp
Priority date: 1958-10-23
Filing date: 1958-10-23
Publication date: 1960-06-14
Anticipated expiration: 1977-06-14

Description

June 14, 1960 Filed Oct. 23, 1958 FIG.!

NVENTOR KENNETH R. WALLACE FIG.2

BY WEJZa-WL.

AGENT United States Patent MOMENTARY CONTACT SWITCH Kenneth R. Wallace, Delphi, Ind., assignor to Essex Wire Corporation, Fort Wayne, Ind.

m on. 2:, 195a, Ser. No. 769,253

3 Claims. 01. 200-41) This invention relates to electric switches and more particularly to an electric switch of the momentary make and break type.

In certain applications it is sometimes desirable to employ a normally open switch associated with the armature of an electromagnet to momentarily close a circuit in only one direction of armature travel. One example H where such a switch is useful is in an electric door locking system of a vehicle where the armature of an electromagnet is connected with a push rod controlling the locking and unlocking latch of the vehicle doors. An electric switch is associated with each electromagnet to simultaneously energize all electromagnets when one of the push rods is initially moved toward its locking position. It is desired that the electromagnets be only momentarily energized to prevent excess current drain from the battery.

It is an object of this invention to provide an electric switch particularly suited for operation by a reciprocating member which momentarily makes a circuit upon movement of the reciprocating member in one direction and remains open upon movement of the reciprocating member in the reverse direction.

It is another object of this invention to provide an electric switch of the above character which is of simple construction and few parts and which may be easily and inexpensively manufactured.

Other objects and advantages of the invention will be apparent from the following description and accompanying drawing in which:

Figure l is a view partly in section of an electromagnet structure incorporating the invention.

Figure 2 is a plan view of a contact.

Figures 3 and 4 are diagrammatic views illustrating operating positions of the contact.

Referring to the drawing, there is shown an electromagnet embodying the invention and including a coil enclosed within a shell of magnetic material consisting of a cup-shaped housing 12 and a disk 14. A pole piece 16 of magnetic material is secured against the closed end of housing 10 and has a conical cavity 18 to conform to the conical end 20 of an armature 22 slidable in nonmagnetic tube 24.

Housing 12 is provided at its open end with a peripheral outwardly extending flange 26 to which a cover 28 is secured by swaging. Cover 28 is centrally apertured to receive a bushing 30 through which extends the actuating end 32 of armature 22. Actuating end 32 is reduced in diameter in two steps or portions 34 and 36. Portion 34 extends from shoulder 38 and terminates at shoulder 40 which abuts against bushing 30 to limit movement of arm'ature 22 to the right as seen in Figure l. Portion 34 is formed with a peripheral projection 42 comprised of a pair of

beveled surfaces

44 and 46 merging at a ridge 48.

Carried by armature 22 is a movable contact 50 which may be stamped from resilient sheet metal such as spring brass. Contact 50 comprises a generally annular base portion 52 having three

leg portions

54, 56 and 58 extending in the same direction from its inner periphery.

2,941,056 Patented June 14, 1960 The

leg portions

54, 56 and 58 are each bent at an angle of about 45 degrees and have laterally bent ends 60 normally in close adjacency with beveled surface 44 of armature 22 and engaging ridge 48. Rotary movement of contact 50 is prevented by forming a notch 62 in the outer periphery of base portion 52 in which extends a guide 64 having a laterally bent arm 66 at its free end.

A spring contact 68 of suitable spring metal is provided near one end with a contact element 70 pressed outwardly from one side which engages armature 22 for connecting contact 50 into the circuit to be controlled. Guide 64 and spring contact 68 may be positioned on a spacer 72 and suitably secured to housing 12. A portion of the periphery of base portion 52 of contact 50 is cut away at 73 to provide suitable clearance between contact 50 I and spring contact 68 in one position of contact 50 to be described later. Diametrically opposite guide 64 and contact 68, one end of a fixed contact 74 is supported upon housing 12 intermediate two insulators 76. Contact 74 has a laterally extending end portion 78 lying in generally parallel spaced relation with the base 52 of contact 50 in the position of armature 22 shown in Figure 1. As will be apparent later, end portion 78 provides a fixed contact portion momentarily engaged by contact 50. An insulator 80 may be disposed between disk 14 and contacts 68 and 74.

Assuming that the parts are positioned as illustrated \in Figure 1, initial movement of the armature 22 to the left upon either mechanical actuation of actuating end 32 or energization of coil 10 will move contact 50 into engagement with end portion 78 of contact 74. Contact 74 is relatively rigid and acts to hold the adjacent por tion of contact 50 against further movement. Continued movement of armature 22 forces the end 60 of leg 54 out of engagement with shoulder 38 and tilts contact 50 as illustrated in Figure 3. With continued movement of armature 22, the end of finger 54 snaps over ridge 48 into engagement with beveled surface 46 as illustrated in Figure 4 which showns the armature 22 in its left hand operating position. As the same time, contact 50 disengages from end portion 78 of contact 74 thereby opening the momentarily closed circuit from contact 74 to contact 68.

Upon reverse movement of armature 50 to the right, contact 50 will not engage fixed contact 74 but remains in its tilted position until the lower edge of base portion 52 engages cover 28. This forces the end 60 of spring 54 over ridge 48 and into engagement with ridge 48 and shoulder 38 to return contact 50 to the position shown in Figure 1.

From the foregoing, it will be seen that the arrangement of the various components of the momentary switch results in an extremely compact arrangement which operates smoothly at all times and is dependable in operation. The switch is simple in construction and is readily adapted to be assembled from a small number of parts which may be inexpensively manufactured.

While the invention has been illustrated and described in its preferred embodiment and has included certain details, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as claimed.

What is claimed is:

1. In an electric switch, an electromagnet including an armature mounted for reciprocal movement between two operating positions, said armature having a shoulder and a reduced diameter portion comprised of two beveled surfaces merging at a ridge spaced from said shoulder, a movable contact having a generally-annular base surrounding said reduced portion of said armature, three spring legs extending in the same direction from the inner periphery of said base, each of said legs having a laterally-bent end resiliently grasping said armature for supporting said movable contact on said armature in either of two positions relative thereto, said legs engaging said shoulder and said ridge in a first position of said movable contact, the end of one of said legs engaging the beveled surface of said armature distant from said shoulder in a second'and different position of said movable contact, a fixed contact supported by said electromagnet for engagement by said base only upon movement of said armature from its operating positions with said movable contact in its first position, said fixed contact cooperating with said base to cause said end of said one leg to move over said ridge after said base engages said fixed contact for shifting said movable contact to said second position thereof upon movement of said armature from one of its operating positions, a stop positioned to be engaged by said base in said second position of said movable contact as said armature is returned to said one of its operating positions, said stop cooperating with said base to cause said end of said one leg to move over said ridge into engagement with said shoulder and ridge for returning said movable contact to said first position thereof, a guide having an edge positioned in parallel spaced relation with said armature, and said basebeing provided with a slot in which said guide is received to prevent rotary movement of said movable contact about said armature.

2. In an electric switch, an actuating member mounted for reciprocal movement between two operating positions, a projecting element on said actuating member comprising two beveled surfaces merging at a ridge, movable contact means having a base positioned transversely of the direction of reciprocation of said actuating member, a plurality of spring legs extending from said base and resiliently grasping said actuating member at said projecting element to support said base on said actuating member in either of two positions relative thereto, said spring legs engaging said actuating member on one side tact means cooperating with said base to cause said base to tilt from said one position thereof to the other of said positions thereof upon continued movement of the actuating member after engagement of said stationary contact means by said base, a stop positioned to be engaged by saidbase in said other position thereof as said actuating member is moved toward one of its operating positions and said stop cooperating with said base to cause said base to return from said other position thereof to said one position.

3. In an electric switch, a shaft mounted for reciprocal movement between two operating-positions and having a shoulder, a projecting elementon said shaft comprising two beveled surfaces merging at a ridge spaced from said shoulder, a movable contact having a base s ounding said shaft, three spring legs extending from sai base portion and resiliently grasping said shaft for supporting said movable contact on said shaft in either of two positions relative thereto, the ends of said legs resiliently engaging said shoulder and said ridge in a first position of said movable contact, an end of one of said legs engaging said shaft on the beveled surface distant from said shoulder in a second and different position of said movable contact, said end of said one leg being laterally-bent for movement over said ridge, a' fixed contact positioned to be en gaged by said base only in said first position of the movable contact and only while said shaft is positioned intermediate its two operating positions, said fixed contact cooperating with said base to cause said end of said one leg to move over said ridge for shifting said movable contact to said second position thereof upon continued movement of said shaft from one of its operating positions after engagement of said fixed contact by said base, a stop positioned to be engaged by said base in said second position of said movable contact as said shaft is returned to said one operating position thereof, and said stop cooperating withsaid base to cause said end of said one leg to move over said ridge for returning said movable contact to said first position thereof.

References Cited in the file of this patent UNITED ST ATES' PATENTS 2,586,056 Kling et Feb. 19, 1952 2,844,680 Christy et a1. July 22, 1958