Transmission device

• US 5,351,051 A
• Filed: 06/25/1992
• Issued: 09/27/1994
• Est. Priority Date: 06/25/1991
• Status: Expired due to Fees

• Current Assignee: Honda Lock Manufacturing Company Limited (Honda Motor Company)
• Original Assignee: Honda Lock Manufacturing Company Limited (Honda Motor Company)
• Inventors: Matsushita, Munemasa, Yano, Tsunenori
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): Johnson, Tim
• Application Number:
  US07/903,907
• Time in Patent Office: 824 Days
• Field of Search: 174/35 R, 174/51, 174/52.1, 174/52.4, 361/424, 361/212, 361/380, 340/825.31, 340/825.36, 340/825.72, 341/176
• US Class Current: 341/176
• CPC Class Codes: G07C 9/00944 Details of construction or manufacture
• CPC Class Codes: H01H 9/0214 Hand-held casings
• CPC Class Codes: H05F 3/02 by means of earthing connections

Abstract

A transmission device having a transmission circuit contained within a casing made of a synthetic resin for transmitting a locking or unlocking signal, wherein an earth plate is disposed between the casing and the transmission circuit. Static charges accumulated on a human body scarcely flow to the transmission circuit upon handling the transmission device, thus eliminating the worry that the electric components of the transmission device are damaged by a surge current.

Claims

1. A transmission device comprising:

a transmission circuit for transmitting a remote control signal for locking and unlocking a vehicle door;

a casing containing said transmission circuit;

at least two portions of said casing having lower dielectric strengths than at least one other portion of said casing;

a plurality of grounding plates between said transmission circuit and said casing;

each of said at least two portions being adjacent to at least one of said plurality of grounding plates;

means for electrically interconnecting said plurality of ground plates, whereby a conductive path joining said at least two portions is established.

2. A transmission device, comprising:

a transmission circuit for transmitting remote control signals for remotely locking and unlocking a vehicle door;

a casing containing said transmission circuit;

said casing having weak-dielectric portions and strong-dielectric portions;

said weak-dielectric portions and said strong-dielectric portions having respective inner faces facing an inside of said casing and respective outer faces facing away from said inside;

said weak-dielectric portions having lower dielectric strengths than said strong-dielectric portions; and

at least one conductive element in said casing for electrically connecting said inner face of at least one of said weak-dielectric portions with said inner face of at least another of said weak-dielectric portions, whereby a low resistance path is established between said inner face of said weak-dielectric portions and said outer face of said at least another.

3. Apparatus as in claim 2, wherein:

said transmission circuit includes a switch for controlling said transmission circuit;

said casing includes a flexible cover covering said switch;

said at least one of said weak-dielectric portions includes said flexible cover; and

said at least one conductive element includes a first ground plate beneath said flexible cover.

4. Apparatus as in claim 2, wherein:

said casing includes at least two casing elements;

said at least two casing elements are connected along an interface between said at least two casing elements;

said at least one of said weak-dielectric portions includes at least a portion of said interface; and

said at least one conductive element includes a second ground plate between said transmission circuit and said interface.

5. Apparatus as in claim 2, wherein:

said casing includes a cover;

said cover retains a battery inside said casing;

said at least one of said weak-dielectric portions includes a metal bolt securing said cover; and

said at least one conductive element includes a first ground plate adjacent to said metal bolt.

6. A transmission device, comprising:

a transmission circuit for transmitting remote control signals for remotely locking and unlocking a vehicle door;

a casing containing said transmission circuit;

said casing including an upper case and a lower case joined at a joining face between said upper case and said lower case;

said upper case including a flexible switch cover forming a portion of said casing;

said flexible switch cover covering a switch that controls said transmission circuit;

a first ground plate beneath said flexible switch cover;

a second ground plate between said transmission circuit and said joining face of said casing; and

means for electrically connecting said first ground plate and said second ground plate.

7. A transmission device, comprising:

a transmission circuit for transmitting remote control signals for remotely locking and unlocking a vehicle door;

an electric cell;

a casing containing said transmission circuit;

said casing including an upper case and a lower case joined at a joining portion between said upper case and said lower case;

said lower case including a detachably mounted cover for said electric cell for replacement of said electric cell;

said cover for said electric cell being secured by a metal bolt;

a first ground plate near said bolt;

a second ground plate between said transmission circuit and said joining portion; and

means for electrically connecting said first ground plate and said second ground plate.

8. A transmission device, comprising:

a transmission circuit for transmitting remote control signals for remotely locking and unlocking a vehicle door;

a casing containing said transmission circuit;

said casing being made of synthetic resin;

said casing including a cover;

said cover retaining a battery inside said casing;

said cover being secured by a metal bolt;

a first ground plate adjacent to said metal bolt;

said transmission circuit including a switch for controlling said transmission circuit;

said casing including a flexible cover covering said switch;

a second ground plate adjacent to said flexible cover; and

means for electrically connecting said first ground plate to said second ground plate.