Switching device for detecting rotational positions of rotary shaft

• US 4,417,468 A
• Filed: 09/11/1981
• Issued: 11/29/1983
• Est. Priority Date: 02/19/1981
• Status: Expired due to Fees

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation), Toyota Jidosha Kogyo Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation), Toyota Jidosha Kogyo Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Nakamura, Kazumasa, Yasuda, Keiichi, Ori, Takaaki
• Primary Examiner(s): Frankfort, Charles E.
• Assistant Examiner(s): Schuster, David R.
• Application Number:
  US06/301,450
• Time in Patent Office: 809 Days
• Field of Search: 73/118, 200/61-39, 200/11 DA, 200/11 TW, 200/11 K, 200/11 EA, 200/39 R, 200/11 R, 200/11 G, 200/14, 200/11 A
• US Class Current: 73/114.36
• CPC Class Codes: G01D 5/252 a combination of conductors or channels
• CPC Class Codes: H01H 19/585 provided with printed circuit contacts
• CPC Class Codes: H01H 21/34 adapted for actuation at a limit or other predetermined position in the path of a body, the relative movement of switch and body being primarily for a purpose other than the actuation of the switch, e.g. door switch, limit switch, floor-levelling switch of a lift

Abstract

A switching device for detecting the rotational positions of a rotary shaft including a lever rotating with the rotary shaft as a unit, and an electrically conductive plate spring having a central portion and two side portions which is bent and mounted on the lever. The two side portions of the plate spring are each formed with a movable electrical contact, and electrical contacts each juxtaposed against one of the movable electrical contacts on the plate spring are formed in fixed members respectively. Rotation of the lever brings one set of movable and fixed contacts into and out of engagement with each other to detect one rotational position, and further rotation thereof brings the other set of movable and fixed contacts into and out of engagement with each other to detect another rotational position. The plate spring is held in position in flexed condition on the lever by retaining means which has the effect of positively keeping the two contacts with each other. A rotor rotated by the lever with a certain amount of hysteresis may be provided, and the contact cooperating with one of the movable contacts on the plate spring for detecting the second rotational position may be mounted on the rotor. The rotor may further have a plurality of contacts for engaging conductors printed in the form of a comb on a printed board.

Claims

1. A switching device for detecting the rotational position of a rotary shaft, comprising:

a lever provided for rotating with the rotary shaft;

a rotor rotated by the lever with a certain amount of hysteresis between the rotor and the lever;

an electrically conductive plate spring which is bent and mounted on the lever, said plate spring including a central portion which is fixed on said lever and two side portions each disposed on one side of the central portion;

projections formed on the lever for holding the side portions of the plate spring in position in fixed condition;

first and second movable electrical contacts each mounted on one of the side portions of the plate spring;

a first electrical contact formed on a fixed member for cooperation with said first movable electrical contact for detecting a first rotational position of the rotary shaft; and

a second electrical contact formed on the rotor for cooperation with said second movable electrical contact for detecting a second rotational position of the rotary shaft.

2. A switching device as claimed in claim 1, wherein said plate spring is bent substantially in the form of a letter W.

3. A switching device as claimed in claim 1, wherein said plate spring is formed by connecting in back-to-back relation two plate spring pieces each bent in the form of a letter U.

4. A switching device for detecting the rotational position of a rotary shaft, comprising:

a lever provided for rotating with the rotary shaft;

a rotor rotated by the lever with a certain amount of hysteresis between the rotor and the lever;

an electrically conductive plate spring which is bent and mounted on the lever, said plate spring including a central portion and two side portions each disposed on one side of the central portion;

projections formed on the lever for holding the side portions of the plate spring in position in fixed condition;

first and second movable electrical contacts each mounted on one of the side portions of the plate spring;

a first electrical contact formed on a fixed member for cooperation with said first movable electrical contact for detecting a first rotational position of the rotary shaft;

a second electrical contact formed on the rotor for cooperation with said second movable electrical contact for detecting a second rotational position of the rotary shaft;

a printed board on which conductors are printed in the form of a comb; and

a plurality of contacts mounted on the rotor for engagement with the conductors on the printed board.