Electric switch with two switching parts acting at different times

• US 4,286,125 A
• Filed: 09/06/1979
• Issued: 08/25/1981
• Est. Priority Date: 09/07/1978
• Status: Expired due to Term

• Current Assignee: J & J Marquardt
• Original Assignee: J & J Marquardt
• Inventors: Stratmann, Uwe, Schaffeler, Alois
• Primary Examiner(s): Truhe, J. V.
• Assistant Examiner(s): Ginsburg, Morris
• Application Number:
  US06/072,829
• Time in Patent Office: 719 Days
• Field of Search: 200/157, 200/6 R, 200/6 A, 200/6 B, 200/6 BA, 200/6 BB, 200/6 C, 200/153 R, 200/153 L, 200/153 LA, 200/153 LB, 200/68, 310/48
• US Class Current: 200/6.00B
• CPC Class Codes: H01H 15/102 comprising cam devices
• CPC Class Codes: H01H 9/061 enclosing a continuously variable impedance

Abstract

An electric switch comprises a switch housing having a contact arm pivotally mounted on a conductive bearing. The contact arm includes a movable contact which is disposed in the housing to engage with a fixed contact of the housing in one position of the contact arm. It also includes a hook shaped end which engages on a cam surface of a slider portion of an actuating member. The contact arm is loaded by a tension spring which is mounted in the housing so that it is urged in a direction to engage the moving contact thereon with the fixed contact in the housing when the slider, which is moved by the actuating member is moved so as to permit the contact arm to pivot. The switch housing advantageously includes a second housing portion with a second switching mechanism similar to the first but which is moved during the movement of the actuating member under the control of a cam slider portion of the actuating member and that it moves faster and causes engagement of its movable contact with a fixed contact in the housing faster than the other contact arm. The actuating member itself is advantageously provided with an electrical switch member which rides over a resistance so as to cut in and out a resistance to control, for example, the speed of operation of an electric motor which is first switched on by engagement of a movable contact with a fixed contact.

Claims

1. An electric switch comprising a switch housing having a first chamber, a first contact arm in said housing chamber, bearing means pivotally supporting said first contact arm in said housing, said first contact arm having a first lever arm portion with a first movable contact thereon and an opposite second lever arm portion, a first fixed contact in said housing opposite to said first movable contact in a position to be engaged by said first movable contact when said first contact arm is pivoted, a loading spring mounted in said housing and connected to said first lever arm portion biasing said first lever arm portion in a direction to move said first movable contact into engagement with said first fixed contact, an actuator mounted in said housing for movement and having a first cam portion engageable with said second lever arm portion which in the first position of said actuator holds said first contact arm in a first operating position with said first movable contact spaced away from said first fixed contact, said actuator being movable so that said first cam portion permits rotation of said first contact arm under biasing of said spring to hold said first movable contact in electrical contacting engagement with said first fixed contact, said housing having a second chamber, a second contact arm pivotally mounted in said second chamber and having a first lever arm portion with a second movable contact thereon, said housing having a second fixed contact in said second chamber, said second contact arm having an opposite second lever arm portion, said actuator including a second cam portion engageable with said second lever arm portion of said second contact arm and holding said second lever arm portion of said second contact arm so that said second movable contact is out of engagement with said second fixed contact, a second loading spring connected to said first lever arm portion of said second contact arm, said second cam portion of said actuator permitting faster movement of said second contact arm than said first contact arm so that said second contact arm is moved to engage said second fixed contact with said second movable contact faster than said first movable contact engages said first fixed contact.

2. An electric switch according to claim 1 wherein each loading spring comprises a tension spring having one end connected to said housing and an opposite end connected to its respective first lever arm portion.

3. An electric switch according to claim 1 wherein said bearing support means comprises an electrically conducting member having a terminal portion.

4. An electric switch according to claim 1 wherein said first and second chambers are disposed side by side in said housing, said actuator has said first and second cam portions which are provided at mutually spaced locations.

5. An electric switch according to claim 1 wherein said second cam portion of said actuator has a bearing surface engageable with said second lever arm portion of said second contact arm with an edge which is steeper than the first cam portion engageable with said first contact arm.

6. An electric switch according to claim 1 wherein said actuator comprises a member adapted to receive an electronic control resistor thereon which is displaceable to vary resistance in an electrical control circuit.

7. An electric switch according to claim 1 wherein said actuator is adapted to have a resistance for varying a control circuit.

8. An electric switch according to claim 7 wherein one of said second contact arms is adapted to be engaged to short circuit the control circuit.