US1952405A

US1952405A - Electric switch

Info

Publication number: US1952405A
Application number: US422752A
Authority: US
Inventors: Vincent G Apple
Original assignee: Bendix Brake Co
Current assignee: Bendix Brake Co
Priority date: 1930-01-23
Filing date: 1930-01-23
Publication date: 1934-03-27
Anticipated expiration: 1951-03-27

Description

March 27, 1934. v APPLE 1,952,405

I ELECTRIC SWITCH Filed Jan. 23, 1930 Z0 I 4x l INVEN'I'OR. t Vincent \flppie ATTORNEYS ing elements.

Patented Mar. 27, 1934 UNITED STATES PATENT OFFICE ELECTRIC SWITCH corporation of Illinois Application January 23, 1930, Serial No. 422,752

Claims.

My invention relates to electric switches, and has particular reference to a switch in which is incorporated a resistance element.

An object of my invention is to eliminate the 5 necessity of providing a separate unit, perhaps in the form of a rheostat, when it is desirable to insert varied resistance in an electric circuit. This is often necessary where modern electric brakes are used on an automotive vehicle and 19 varying current strengths are essential to produce varied degrees of braking power.

Heretofore a circuit has been closed through electric brakes with a conventional electric switch and an independent unit in the form of a 5 carbon pile rheostat, or the like, for varying the current strength. through the electric brakes in proportion to the effort exerted upon the brake pedal.

My inventive concept resides in the utilization of the switch member per se to produce a plurality of stages of amperage in the electric circuit with a given voltage.

A further object of my invention is to so design this combination that upon initial movement of the switch button an electric circuit is made,

including a resistance element which is a portion of the switch unitper se. Upon further movement of the switch, this resistance element is shunted out and the current flow permitted in its full strength.

Further objects and meritorious features of my invention will become apparent from the following description, taken in conjunction with the drawing wherein like numerals refer to like 7 5 parts throughout the several figures and wherein:

' '40 which my switch is utilized in conjunction with an electric motor and storage battery.

Numeral 10 designates the housing for my switch elements, and to this housing is secured the cover 12 which encloses the various operat- The

terminals

14 and 16 are secured in place by means of the nuts 18 and insulated from the housing 10 by

insulation strips

20 and 22.

A contact plate 24 is secured loosely on the rod 1.50 26 and insulated therefrom by means of the washers 28. This contact plate is normally held in open circuit position, that is, out of contact with the

members

14 and 16, by means of the

balanced springs

30 and 32. A tubular member 7 5.5 34, over the outer extremity of which is telescopically mounted a cap 36, encloses the spring 30 and the rod 26.

soldered to the plate 24 and the terminal 38 is a metal strip 40. This metal strip is insulated by the strips 42 and constitutes a conductor from the contact plate 24 to the resistor element which I have indicated by the numeral 44. There is no particular type of resistance which need be utilized in conjunction with this assembly, and for that reason I have indicated it broadly with a single numeral. This resistor element 44 is connected to the terminal 18 and thus makes an electrical connection from the terminal 38 to the terminal 18.

As will be noted from Fig. 1 the contact member 14 is disposed closer to the contact plate 24 than is the contact member 16. It is thus apparent that on depression of the pedal stem 26 the contact plate 24 will first come into contact with contact member 14, thus creating a circuit through the terminal 14, plate 24, strip 40, terminal 38, resistor element 44, and back to terminal 18. On iurther depression of the pedal, or switch stem 26, the plate 24 will contact the contact member 16, thus short circuiting the resistor, or shunting it out of circuit, and permitting the full current to flow in the circuit.

Operation of my switch member is apparent from the foregoing description, and it is obvious that when the

terminals

14 and 16 are hooked up with any desirable electric brake power mechanism, varied amperages may be made to flow through such power mechanism and thus apply varying brake pressure. Although I have illustrated the insertion of but one resistor element in my combination switch device I contemplate the possibility of inserting others and thus permitting still a greater number of amperage stages in the circuit.

Having illustrated a preferred embodiment of my invention various others will be apparent to those skilled in the art, and for that reason I limit myself only within the scope of the appended claims.

I claim:

1. An electric switch having a casing, a stem slidable therethrough, a contact bridge carried by said stem within the casing, a pair of contacts supported within the casing at unequal distances above said bridge, a resistance connected with the contact more remote from the bridge, a third contact supported within the casing underneath said bridge and connected with the resistance, means normally holding said bridge out of contact with the pair of contacts and in contact with said third contact underneath the bridge, said stem being slidable to move the bridge into contact with the nearest of said pair of contacts while remaining in contact with the contact underneath the bridge and being movable further in the same direction to cause the same to bridge the pair of contacts.

2. An electric switch having a casing, a stem slidable therethrough, a bridge contact member carried by said stem within the casing, a pair of contacts supported within the casing at unequal distances from said bridge member, a resistance connected with the contact more remote from the bridge member, a third contact supported within the casing and connected with the resistance, means normally holding said bridge member out of engagement with the pair of contacts and in engagement with said third contact, said stem being slidable to move the bridge into engagement with the nearest of said pair of contacts while remaining in engagement with said third contact, said bridge being movable further in the same direction to cause the same to connect the pair of contacts.

3. In an electric circuit, a switch comprising a control member, a switch blade supported thereon, a pair of contacts spaced unequal distances from said blade, a resistance connected with the more remote of said pair of contacts, a third contact connected with the resistance, means holding said switch blade out of engagement with said pair of contacts and in engagement with said third contact, said switch blade being movable to establish contact first with one of said pair of contacts and then with the other, said third contact adapted to maintain its contact with said switch blade during movement of the blade in the establishment of contact with the first of said pair of contacts.

4. In an electric circuit, a switch comprising a casing, a switch blade tiltably supported within the casing, a pair of contacts spaced unequal distances from said blade, a resistance connected with the more remote contact of said pair, a third contact connected with the resistance, means supporting said blade normally out of contact with said pair of contacts and normally in contact with said third contact, said switch lade being movable to establish contact first with the nearest of said pair of contacts and then under continued movement to tiltably establish contact with the more remote of said pair of contacts, said third contact member being adapted to follow said switch blade in its movement in making contact with the nearest of said pair of contacts.

5. In an electric circuit, a switch having a tiltably supported switch blade, a pair of contacts spaced unequal distances therefrom, means yieldably holding said blade normally out of contact with said pair of contacts, said blade being movable to establish contact successively with the contacts of said pair and adapted to tilt to establish contact with both contacts of the pair,

a resistance connected with the contact of said pair which is more remote from the blade, a third contact connected with the resistance and. 195 comprising a spring member adapted normally to contact the switch blade in the normal position of the blade and adapted'to follow the blade and retain contact therewith during the movement of the blade to establish contact with the nearest of the pair of contacts.

VINCENT G. APPLE.