US2523774A - Electromagnetic switch - Google Patents

Description

sept. 26, 195o n. E. MQRAN 2,523,714

ELECTROMAGNETIC swI'rcl-r Y Filed April 25. 194s pim 1 @main I f' @ma Inventor: Don E. Moan,

His Attorney.

Patented Sept. 26, 1950 2,523,774 ELECTROMAGNETIC SWITCH Don E. Moran, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application April 23, 1948, Serial No. 22,745

(Cl. 20G-87) Claims.

My invention relates to electric switches, and

Y more particularly to shockproof electromagnetically operated switches of the type known as contactors, and has for its main object a simple, reliable and shockproof electric switch.

In carrying out my invention, I provide an operating mechanism for a plurality of movable switch contacts com-prising a contact supporting member for movement substantially perpendicular to a base supporting same, together with a link member to move the contact supporting member, said link being provided with a slot defining a cam surface for engagement with the contact supporting member and so arranged as to constrain same against shock movement in a direction parallel thereto. A lever is connected to an operating magnet to impart motion to the link member, said lever being counterbalanced to overcome shock movement of the lever around the pivotal point thereof when said shock movement is in a direction substantially parallel to the movement of the link member.

For a more complete understanding of my invention, reference is had to the accompanying drawing, Fig. l of which is a top elevational view with a portion of the cover broken away to illustrate part of the contact structure; Fig. 2 is a. partial side elevational section taken along the line 2 2 of Fig. 1; F ig. 3 is a similar partial side elevational section along the line 3 3 of Fig. 1; Fig. 4 is a bottom elevation view; and Fig. 5 is a fragmentary view, partly in section, of part of the switch assembly.

Referring to the drawing, I have shown a switch embodying my invention in one form and vcomprising a metal base member l0 to which is y secured an insulating support member Il. To the right-hand portion of said member Il is secured, by means of bolts, rivets, or the like, two parallel rows of contact supporting members, one row I 2--I 5 being visible in Fig. l and one support I6 of the other row being shown in Fig. 2. The last-mentioned supporting members serve to support a plurality of fixed contacts 20 which are removably secured to their respective supports. Each contact 20 comprises a simple, substantially nat, rectangular member, apertured at one end for securing same to the respective rsupport and provided with a contact surface 20A, preferably of silver, at the oppositel end. The aforementioned arrangement of the contactspermits their ready removal for replacement if necessary and for further reasons which will be presently explained.

The insulating supporting member Il is provided with a row of centrally located apertures 2| extending perpendicularly from the base I0. Through each of the respective apertures there extends a slidable switch member or movable contact support 22 bearing on the upper end thereof a pluralityA of removably secured contacts 23. The contacts 23 are also flat rectangular members differing from the ilrst-named members in that both ends are provided with silver contact surfaces 23A and the center portion apertured for the disposal of a screw 23B to hold the contact member in place. The apertures (not shown) in the contacts 23 are made large enough so that they are free to rock about the screws 23B. The switch members 22 are integrally connected to a member 2l disposed between the member Il and the base I0 and located traversely of said base as shown in Fig. 4.

The particular means for securing the llxed and movable contacts 2l and 23 permit these contacts to be rearranged to provide circuit positions which are normally open, normally closed or any combination of normally open and closed positions. The term normally refers to the space relation of the contacts when current is not flowing in a circuit (not shown) utilizing the switch. In Fig. 2, the arrangement of the complementa-ry xed and movable contacts provides a normally open position.` By the simple expedient of removing and turning over the contacts 20 and 23 on their respective supports and placing the springs 22A and the contacts 23 on the opposite side of a cross piece 22B on the switch member 22, the contacts will assume a. normally closed position as illustrated in Fig. 5.

Secured to the base I0 adjacent the member Il is a platform member 25 for supporting thereon an electromagnetic core 26 and a coil 2l. Pivotally mounted on said platform is an operating lever 28. The lever is journalled on a shaft 29 which in turn is pivotally secured to the platform 25. I form this lever of a single piece of metal, preferably steel for strength, so as to provide at the upper end thereof an elongated member 30 to which is slidably secured an armature 3| in proper electromagnetic space relation to the core 25. At the\pivotal point of this lever the metal is bent to form a U and it is this portion of the arms 32 of said U which are pivotally mounted on the shaft 29 to form outwardly extending wing-like portions 33.

Means for coupling the lever 2B to the movable supports 22 is provided by a switch actuating link member 34 (see Fig. 3) pivotally secured to an eccentrlcally bored bushing 35. The bushing is journalled on a shaft 36. The shaft is pivotally supported by the lower left hand portions 33 of the lever 28. The bushing is threaded externally and provided with a hexagonal head 31 and a hexagonal nut 38 for securing the link member I4 against movement around the bushing. The arrangement of eccentric bushing and locking nut 38 permits adjustment of the link member 34 along its line of normal movement.

Adjacent the other end of the link member 34, I provide a slot 33 defining a cam for engagement with a cam follower 40. The follower is slidably disposed in a longitudinally located passageway 24A in the member 24, as illustrated in Fig. 4.

The slot 39 is inclined with respect to the longitudinal axis of the base I0 and the ends thereof define a pair of substantially vertical offset openings 4| and 42 of appreciable length. As above arranged, the follower comes to rest in one or the other of said vertical openings depending on the position of the armature 3| as shown in Figs. 2 and 3. The cam follower.4|| is a rod or pin transversely disposed with respect to the link 34 and having its center disposed in the cam slot 39. On each side of the link 34, the pin 40 has journaled therein the ends 24 of one of the slidable switch members 22. mounted at its ends upon the free ends of a pair of pivoted swing links 40A and 4||B, the other ends of which are pivotally mounted upon a pair of fixed trunnions 40C and 40E in the support25. The cam rod 40 is thus constrained to move laterally in a short arc about the xed trunnions 43C and 40D.

Means for constraining the movement of the link member 34 in a direction substantially parallel to the base is provided by a roller 43 (see Fig. 3) secured to a support 44 which is attached to said base adjacent the support member The link member is provided with a protuberance which serves to reduce the amount of surface contact of the link member with a trough 46 formed in the base. The trough serves to constrain lateral movement of the link member.

The vertical end portions 4| and 42 of the slot 33 provide the means for overcoming shock movemerit of the movable support 22 when the force of impact applied to the base is in a direction parallel to said support or to the right or left with respect to the observer. The roller 43 in addition to its first-mentioned function also aids in overcoming the aforementioned shock movement.

In order to overcome shock movement due to impact in a vertical or up and down direction, I provide a plurality of weights 41 and 48. These weights are eccentrically and pivotally mounted on the inner sides of the portions y33 and are secured theretoV by a nut and bolt arrangement 43. This arrangement permits the weights to be adjusted to produce a state of equilibrium of the mass around the shaft 29 and so compensatesfor the various weights of the movablev support 22, link member 34, lever 28 and the armature 3|. Thus, impact in the direction mentioned cannot cause rotation of the mass about the shaft 29 thereby preventing undesirable engagement or disengagement of the contact members.

Means for biasing the armature 3| to a position of disengagement with the core member 26 is provided by a helical spring secured by one end to the link member 34 and by the other end to a support 5| secured to the base I0. A second helical spring 52 adjustably secured to the support 5| serves to overcome any bouncing eilect when the armature 3| is released, the mass of the The cam rod or pin 40 is v 4 spring 52 being made small enough to absorb the shock.

I also provide in my invention, as illustrated in Fig. l, a so-called interlocking switch for maintaining a flow of current in the coil 21 comprising a pair of fixed contacts 53-54 and a pair of coacting movable leaf spring contacts -55. These contacts are secured, respectively, to the support and one of the movable supports 22 and are connected in series with the coil 21. The aforementioned arrangement is such that shock movement in any direction will not disengage the contacts 53-56 despite the possibility that such shock movement may momentarily disengage the remaining contacts 20 and 23. The contacts 53-54 are flat members disposed in perpendicular relation to the top of the support and arranged to contact the inner surfaces of the leaf spring contacts 55-56.

A cover 51 composed of molded flame-proof electric insulating material, and having a plurality of chambers 53, serves to completely enclose each of the complementary fixed and movable contacts. and is provided to prevent flashover between said contacts. The lower edges of the walls comprising the chambers are disposed in cooperating recesses 53, as illustrated in Fig. l.

In conclusion, it will be readily appreciated that my invention provides a very simple, rugged and positively shock-impact-proof switch and, while I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto, since many modifications may be made, and I therefore contemplate by the appended claims to cover any such modications as fall within lthe true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. In a shock-proof electromagnetic switch, a slidable switch actuating link having a cam slot, a cam pin disposed in said slot, a pivoted link coupled to said pin and constraining said pin to limited arcuate lateral movement about a fixed r pivot and substantially perpendicularly to the direction of motion of said actuating link, a slidable switch member coupled to said pin. and an electromagnet having a movable armature coupled to said actuating link.

2. In a shock-proof electromagnetic switch, a slidable switch actuating link having a cam slot angularly disposed with respect to the direction of movement of said actuating link,'a cam follower pin disposed'in said slot, a swing link mounting said pin for limited lateral movement about a fixed pivot and substantially perpendicurlarly 'to the direction of movement of said actuating link, a switch member coupled to said cam -pin and slidably mounted for movement substantially perpendicularly to the direction of movement of said actuating link, and an electro-- disposed substantially parallel to the direction of movement of said member and an intermediate angularly disposed connecting portion, a cam follower coupled to said actuating member and movable along said cam surface, a pivoted link coupled to said cam follower and arranged to constrain said follower to limited arcuate movement 5 about a fixed pivot and substantially perpendicularly to the direction of said motion of said actuating member, a movable switch member coupled to said cam follower, and an electromagnet having a movable armature coupled to said actuating member.

4. In a shock-proof electromagnetic switch, a ilat base, an actuating link mounted for sliding movement along said base and having a cam slot, said slot being angularly disposed with respect to the direction of movement of said actuating link, a supporting bracket extending from said base, a pair of swing links mounted upon aligned trunnions carried in said bracket, a cam pin disposed in said slot and mounted upon said swing links for limited lateral arcuate movement substantially perpendicularly to said base, a plurality of switch members pivotally connected to said cam pin and mounted for sliding movement substantially perpendicularly to said base, an electromagnet having a pivoted armature connected to actuate said actuating link, said link and armature being substantially balanced about the armature pivot.

5. In a shock-proof electromagnetic switch, a ilat base, a contact support and a magnet support extending from said base in substantially parallel spaced relation, an operating member pivotally mounted intermediate its ends upon said magnet support and including a movable armature, an electromagnet mounted on said magnet support in attractive relation with said armature, an actuating link coupled to said operating member and slidably mounted for movementalong said base, said actuating link including a cam slot angularly disposed with respect to the direction of movement of said actuating link, said operating member and said actuating link being substantially balanced about the operating member pivot, a pair of swing links pivotally mounted on trunnions on said magnet support and extending in substantially parallel spaced relation along said base, a cam pin mounted on said swing links and disposed in said cam slot for movement toward and away from said base upon movement of said actuating links and an elongated switch member coupled to said cam pin and slidably mounted on said contact support for movement substantially perpendicularly to said base.

DON E. MORAN.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS

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