Variable capacitor

• US 4,594,640 A
• Filed: 08/30/1984
• Issued: 06/10/1986
• Est. Priority Date: 03/27/1984
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Tatsumi, Tetsuo
• Primary Examiner(s): GRIFFIN, DONALD
• Application Number:
  US06/645,752
• Time in Patent Office: 649 Days
• Field of Search: 361/277, 361/292, 361/293
• US Class Current: 361/293
• CPC Class Codes: H01G 5/06 due to rotation of flat or substantially flat electrodes

Abstract

Disclosed herein is a variable capacitor in sealed structure having the following construction: Within an insulating case being opened at one side, a stator electrode and a rotor electrode are arranged in a state being opposed to each other through a dielectric plate. The rotor electrode is formed in one surface of a metal rotor rotatably arranged within the insulating case. The other surface of the metal rotor is directed toward the opening of the insulating case, on which other surface an adjusting groove is formed and a ring-shaped base portion of a resilient presser member is arranged in a state not obstructing the adjusting groove. Spring portions extend from the base portion of the resilient presser member, to be in contact with the other surface of the metal rotor. An annular sealing member is fixedly provided in the base portion of the resilient presser member. The sealing member encloses the spring portions, to be in contact with the metal rotor in the vicinity of the outer peripheral portion of the other surface thereof as well as the inner peripheral surface of the insulating case.

Claims

1. A variable capacitor comprising:

an insulating case provided with at least one opening;

a dielectric plate arranged within said insulating case;

first and second electrodes arranged within said insulating case to be opposed to each other through said dielectric plate;

a metal rotor rotatably arranged within said insulating case and provided with said first electrode in its one surface, with the other surface thereof being directed toward said opening;

a formation means provided in said other surface of said metal rotor for engagement with a tool for rotating said metal rotor;

a resilient presser member made of metal comprising a base portion fixedly arranged within said insulating case in the side of said other surface of said metal rotor and provided in the form of a ring not to obstruct said formation means and spring portions integrally extending from said base portion for applying pressure with respect to said metal rotor in the vicinity of the outer peripheral portion of said other surface thereof; and

an annular sealing member fixed with respect to said base portion of said resilient presser member to block a path defined between said other surface of said metal rotor and the peripheral portions of said opening in the vicinity of the outer periphery of said other surface thereof over the entire circumference, said sealing member being formed by elastic material.

2. A variable capacitor comprising:

an insulating case provided with at least one opening;

a dielectric plate arranged within said insulating case;

first and second electrodes arranged within said insulating case to be opposed to each other through said dielectric plate;

a metal rotor rotatably arranged within said insulating case and provided with said first electrode in its one surface, with the other surface thereof being directed toward said opening;

a formation means provided in said other surface of said metal rotor for engagement with a tool for rotating said metal rotor;

a resilient presser member made of metal comprising a base portion fixedly arranged within said insulating case in the side of said other surface of said metal rotor and provided in the form of a ring not to obstruct said formation means and spring portions integrally extending from said base portion for applying pressure with respect to said metal rotor in the vicinity of the outer peripheral portion of said other surface thereof; and

an annular sealing member fixed with respect to said base portion of said resilient presser member to block a path defined between said other surface of said metal rotor and the peripheral portions of said opening in the vicinity of the outer periphery of said other surface thereof over the entire circumference, said sealing member being formed by elastic material;

wherein said spring portions have contact portions being elastically in contact with said metal rotor, and said sealing member is formed to cover said spring portions, while the contact portions of said spring portions are exposed from said sealing member.

3. A variable capacitor in accordance with claim 2, wherein the contact surface of said sealing member with respect to said metal rotor is formed to enclose said contact portions of said spring portions.

4. A variable capacitor in accordance with claim 2, wherein said sealing member is in contact also with the inner peripheral surface of said insulating case.

5. A variable capacitor in accordance with claim 2, wherein said resilient presser member is integrally provided with a rotor terminal, said rotor terminal being outwardly extracted from said insulating case.

6. A variable capacitor in accordance with claim 2, wherein said resilient presser member is retained in a state elastically in contact with said metal rotor by being in engagement with said insulating case in the vicinity of the peripheral edge portion of said opening.

7. A variable capacitor in accordance with claim 2, wherein said formation means is selected in a form to be engaged with the forward end of a screwdriver.

8. A variable capacitor in accordance with claim 2, wherein said second electrode is fixedly retained within said insulating case.

9. A variable capacitor comprising:

an insulating case provided with at least one opening;

a dielectric plate arranged within said insulating case;

first and second electrodes arranged within said insulating case to be opposed to each other through said dielectric plate;

a metal rotor rotatably arranged within said insulating case and provided with said first electrode in its one surface, with the other surface thereof being directed toward said opening;

a formation means provided in said other surface of said metal rotor for engagement with a tool for rotating said metal rotor;

a resilient presser member made of metal comprising a base portion fixedly arranged within said insulating case in the side of said other surface of said metal rotor and provided in the form of a ring not to obstruct said formation means and spring portions integrally extending from said base portion for applying pressure with respect to said metal rotor in the vicinity of the outer peripheral portion of said other surface thereof; and

an annular sealing member fixed with respect to said base portion of said resilient presser member to block a path defined between said other surface of said metal rotor and the peripheral portions of said opening in the vicinity of the outer periphery of said other surface thereof over the entire circumference, said sealing member being formed by elastic material;

wherein said sealing member is retained by said resilient presser member prior to insertion of said resilient presser member into said insulating case.

10. A variable capacitor comprising:

an insulating case provided with at least one opening;

a dielectric plate arranged within said insulating case;

first and second electrodes arranged within said insulating case to be opposed to each other through said dielectric plate;

a metal rotor rotatably arranged within said insulating case and provided with said first electrode in its one surface, with the other surface thereof being directed toward said opening;

a formation means provided in said other surface of said metal rotor for engagement with a tool for rotating said metal rotor;

a resilient presser member made of metal comprising a base portion fixedly arranged within said insulating case in the side of said other surface of said metal rotor and provided in the form of a ring not to obstruct said formation means and spring portions integrally extending from said base portion for applying pressure with respect to said metal rotor in the vicinity of the outer peripheral portion of said other surface thereof; and

an annular sealing member fixed with respect to said base portion of said resilient presser member to block a path defined between said other surface of said metal rotor and the peripheral portions of said opening in the vicinity of the outer periphery of said other surface thereof over the entire circumference, said sealing member being formed by elastic material;

wherein said sealing member is brought into a state fixed to said resilient presser member with unhardened resin for forming said sealing member being injected and then hardened after insertion of said resilient presser member into said insulating case.

11. A variable capacitor comprising:

an insulating case provided with at least one opening;

a dielectric plate arranged within said insulating case;

first and second electrodes arranged within said insulating case to be opposed to each other through said dielectric plate;

a metal rotor rotatably arranged within said insulating case and provided with said first electrode in its one surface, with the other surface thereof being directed toward said opening;

a formation means provided in said other surface of said metal rotor for engagement with a tool for rotating said metal rotor;

a resilient presser member made of metal comprising a base portion fixedly arranged within said insulating case in the side of said other surface of said metal rotor and provided in the form of a ring not to obstruct said formation means and spring portions integrally extending from said base portion for applying pressure with respect to said metal rotor in the vicinity of the outer peripheral portion of said other surface thereof; and

an annular sealing member fixed with respect to said base portion of said resilient presser member to block a path defined between said other surface of said metal rotor and the peripheral portions of said opening in the vicinity of the outer periphery of said other surface thereof over the entire circumference, said sealing member being formed by elastic material;

wherein said insulating case is further provided with a second opening in a position opposed to said opening,

said variable capacitor further including;

a second metal rotor rotatably arranged within said insulating case and provided with said second electrode in its one surface with the other surface thereof being directed toward said second opening,

a second formation means provided in said other surface of said second metal rotor for engagement with a tool for rotating said metal rotor,

a second resilient presser member made of metal comprising a base portion fixedly arranged on said second metal rotor in the side of said other surface of said second metal rotor and provided in the form of a ring not to obstruct said second formation means and spring portions integrally extending from said base portion for applying pressure with respect to said second metal rotor in the vicinity of the outer peripheral portion of said other surface thereof, and

an annular second sealing member fixed with respect to said base portion of said second resilient presser member to block a path defined between said other surface of said second metal rotor and the peripheral portion of said second opening in the vicinity of the outer peripheral portion of said other surface thereof over the entire circumference, said second sealing member being formed by elastic material.