Murata Manufacturing Co., Ltd.

Yukihiro Azuchi

Takami Yamamoto

In a rotary electric device such as a trimmer capacitor or a variable resistor comprising a rotor contained in a case which is provided with an opening for receiving a screwdriver for rotating the rotor from the outside with a clearance being defined between an edge defining the opening and the rotor, a cover sheet is formed in a state covering the clearance and bonded to both of the case and the rotor, whereby the rotary electric device is closed. When the rotor is rotated in an adjusting stage, the cover sheet is readily broken and respective broken and separated parts of the cover sheet are individually retained by the case and the rotor.

Rotary Electric devices

A method of forming a cover sheet over an opening of a rotary electric device such as a trimmer capacitor or a variable resistor. The rotary device includes a rotor located in a housing or case which is accessible through the opening and adjustable by a screwdriver or similar tool. To form the cover sheet, pliable resin is extended while in an unhardened state to form a film. The case is pressed against the film to introduce a part of the film into the opening. Then the resin material forming the film is allowed to partially harden before the case is separated from the film. As a result, part of the film remains in the opening of the case to form the cover sheet. As the film is completely hardened a functional cover sheet over the opening is produced.

Method of forming cover sheet in opening of rotary electric device

A cover sheet for sealingly covering the rotatable head of an adjustable electric device such as a potentiometer, trimmable capacitor or the like. The cover sheet is provided over a screwdriver opening through which the device's capacitance, resistance or the like is set. The cover sheet is formed at the opening and is bonded to the inner peripheral surface of an edge portion which defines the opening. Thereby, the rotary electric device is closed. The cover sheet is preferably formed of a silicone adhesive material.

Rotary electric devices

An electronic component having a rotary mechanism provided with a rotor, including a stator member and a combination component for rotating the rotor such that the rotary mechanism is mounted on the stator member. The combination component includes a plate member formed with a slot and a spring member having an engageable piece engageable with a recess of the rotor so as to be rotated together with the rotor through engagement of the engageable piece of the spring member with the recess of the rotor.

Electronic component having rotary mechanism

A rotary electric component comprising a support structure made of synthetic resin, at least one first elongated electric terminal member made of electroconductive material and having one end positioned exteriorly of the support structure for the electric connection with an external circuit element, a rotor, and a second elongated electric terminal member made of electroconductive material and having one end positioned exteriorly of the support structure for the electric connection with an external circuit element. The second terminal member is supported by the support structure in the form as partially embedded in the support structure and has the other end formed into a tubular shaft for the support of the rotor for rotation thereabout. The shaft integral with the second terminal member is formed by the use of any known metal drawing technique and has a closed end at the tip thereof opposite to the second terminal member. The closed end of the shaft is, after the rotor has been mounted thereon for rotation thereabout relative to the support structure, rivetted or battered so as to expand radially outwardly to a diameter greater than the mounting hole in the rotor through which the shaft extends.

Rotary electric component

A trimmer capacitor is encased in an insulating case. The insulating case holds a stator terminal embedded therein. A dielectric stator is fixedly received in the insulating case and is provided with a stator electrode. The stator electrode is electrically connected to the stator terminal by contact with the exposed portion of the stator terminal within the insulating case. A metal rotor having a rotor electrode is placed on the dielectric stator. A projecting step is formed on the upper surface of the metal rotor. The projecting step is received in a throughgoing hole formed in one end of the rotor terminal and in this state the metal rotor is rotatably supported with respect to the rotor terminal. The throughgoing hole is located in the center of a dish-shaped spring portion. One end of the rotor terminal, including the dish-shaped spring portion, is locked by the upper edge of the insulating case, whereby a suitable amount of torque is attained by the springiness thereof with respect to the rotation of the metal rotor.

Trimmer capacitor

A trimmer capacitor is disclosed. This trimmer capacitor comprises a rotor, a stator, a stator electrode formed in a predetermined pattern on a portion of the stator, and a stator terminal extending outward from the stator for external connection of the stator electrode. Preferably, the stator electrode and a conductive portion extending from the stator electrode to the stator terminal are formed inside of the outer periphery of the stator.

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Sabae, Japan

Yukihiro Azuchi