US1674868A - Electric switch - Google Patents

Description

June 26, 1928.

T. L.- LEE ELECTRIC SWITCH Original Filed June 1921 Hnvemftw I s Patented June 26, 1928.

L. LEE, OF ROCHESTER, NEW YORK, ASSIGNOR TO NORTH EAST ELECTRIC ANY, OF ROCHESTER, NEW" YORK, A GORIPORATION OF NEW YORK.

THOMAS This switche ELECTRIC SVIITCH.

Application filed June 8, 1921, Serial No. 476,050.

invention relates to electric pushs of the type in which a contactmember in the form of a laminated spring is used.

.The object of the invention is to produce a switch of simple and inexpensive construction, w

hich shall be reliable in operation,

and particularly one in which the parts are insulated in a simple but effective manner. In switches of the type in question 1t has been customary to use trolled a spring-conmetal plunger carrying the sprlng contact-member, and to insulate this contactmember from the metal plunger.

It has also been common to prevent rotation of the plunger and of stati ent inv the contact-member by the use insulating material within the In accordance with the presention the construction is simplified onary mounting the contact-member on a plungof insulatmg material, and provldlng this plunger with non-circular projections or keys engaglng corresponding grooves in the casing, so

that rotation of the plunger is prevented.

Other features of the invention will be set forth more particularly in the following description of the illustrated embodiment of the invention.

Figs.

1 and 2 are, respectively, a sideelevation and an end-elevation of a switch embodying the present invention,

together with an instrument-board or the like on which switch is mounted, the switch being shown partly in axial section. Fig. 3 is a plan-vlew of the switch, in section on the line 33 in Fig. 1.

.The illustrated embodiment of the invention comprises a. casing 5 within which two stationary contact-members 6 are mounted and insulated. These contact-members have stems 7 projecting outwardly and ing bin constitutding-posts.

The movable contact-member 8 comprises a set of spring-blades of the usual form. These blades are perforated and are fixed together by means of a metal eyelet 9 and a washer 1O cooperating therewith. The

plunger 11 is formed of insulating material,

prefera bly a plastic material, such as bake- Renewed November 15, 1927.

which can be readily moulded to form. Fixed in the plunger, preferably by mouldingit therein, is a metal insert or core 12, by which the movable contact-member is supported and attached to the plunger. For this purpose the core is knurled for part of its length, and the eyelet 9 is pressed tightly upon the knurled portion as shown inFig. 1, thus being fixed on the core. The lower extremity 13 of the core serves as a guide for the coiled spring 14 by which the plunger is held normally in the raised position, with the contact-members disengaged.

The plunger moves in a bearing or sleeve 15, projecting integrally from the body of the casing 5, and this sleeve is provided with two grooves or kcywa-ys, which are engaged by integral projections or keys 16 formed on the plunger. These keys prevent the plunger from rotating, and thus prevent engagement oi the movable contact-member with the sides of the casing.

The switch as illustrated is designed to be mounted in the form of a flush switch, on a panel or board 17, being secured in place by screws 18 and an escutcheon-plate 19. As so arranged, the upper or outer end of the plunger 11 has the form of a pushbutton, as shown.

The bottom of the casing is formed by a removable plate 20, on which the stationary contact-members are mounted, and this plate may be removed whenever necessary to ad just or repair the mechanism of the switch. It should be noted that owing to the close engagement of the core 12, the eyelet 9 and the contact-blades 8, these parts act substantially as a single solid conductor, so that the conductivity of the movable switchblades is not substantially impaired by perlite,

forating them in the manner shown.

The invention claimed is:

1. In an electric switch, the combination of a casing provided with a bearing-sleeve; fixed contact-members mounted in the easing; a movable contact-member cooperating with said fixed contact members and comprising a plurality of springblades perforated and secured together by a metal eyelet; a metal core fixed in said eyelet; and

a plunger of insulating material, in which said core is fixed, said plunger being slidable in said bearing-sleeve in the casing.

2. In an electric switch, the combination of a casing provided With a bearing-sleeve; fixed contact-members mounted in the easin a movable contact member c00peratb, ing with said fixed contact-members and comprising a plurality of spring blades perforated and secured together by an eyelet; a metal core having a frictionfit in said eyelet; and a plunger, of insulating mate rial, molded on said core and slidingly mounted in said bearing-sleeve in the casing. 7

THOMAS L. LEE.

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