Patent ID: 8836486

Claim:
A portable transmitter comprising: a circuit substrate on which one or more tact switches and circuit modules are mounted; an inner case comprised of a first case and a second case which are assembled into one body, the first case being comprised of a bottom surface and side walls which surround the bottom surface, the second case being comprised of a bottom surface and side walls which surround the bottom surface, the inner case accommodating the circuit substrate so that one surface of the circuit substrate faces the first case, and one or more penetration holes being formed in the first case at a position which faces corresponding tact switches formed on the circuit substrate; a cover placed between the circuit substrate and the first case, and further placed in the inner case with the cover being supported between the first case and the second case in order to seal a space formed between the first case and the second case; an outer case accommodating the inner case and comprised of opening parts formed at a side which faces the tact switches formed on the circuit substrate, and one or more outer knobs of a plate shape placed in the corresponding opening parts, with one surface of each of the outer knobs being exposed to the outside of the portable transmitter, wherein the cover is made of a single piece elastic member and has projection parts, each of the projection parts projects toward a corresponding opening part from a corresponding penetration hole, a front end part of the projection part contacts a corresponding outer knob, and an opposite part of the projection part which is opposite to the front end part contacts a corresponding tact switch when the projection part is elastically deformed, each of the outer knobs is placed in the corresponding opening part while an outer peripheral part of the outer knob is pushed onto the outer peripheral part of the corresponding opening part formed in the outer case by elastic force of the cover; the cover comprises a bottom surface and side walls, the side walls of the cover surround the bottom surface, and the bottom surface of the cover includes the projection parts and load distributing parts, each of the load distributing parts has a non-linear curved shape on the bottom surface of the cover at an outer peripheral part of a corresponding projection part; each of the load distributing parts has a protruding shape which projects toward a direction parallel to a depressing direction when the operator pushes the outer knob; each of the load distributing parts is arranged directly below the corresponding outer knob and has a protruding part of the protruding shape in a direction at right angle to the corresponding outer knob, and the each of the load distributing parts buffers a depressed force generated when the corresponding outer knob is pushed.