Patent ID: 8464766

Claim:
A cassette gas cylinder mounting structure for use in a working machine comprising: a cylinder case adapted to receive a cassette gas cylinder therein; a cylinder mounting mechanism provided in the working machine for mounting thereto the cylinder case, the cylinder mounting mechanism further including: a cylinder case mounting body, a cylinder case retaining rod pivotably mounted on the cylinder case mounting body and normally spring-urged toward the cylinder case mounting body so that the cylinder case can be resiliently pressed against the cylinder case mounting body; a mouthpiece support section provided in the cylinder mounting mechanism for supporting a mouthpiece portion of the cassette gas cylinder when accommodated in the cylinder case; a shutter member pivotably mounted on the cylinder case mounting body and normally spring-urged to close the mouthpiece support section while no cylinder case is being mounted to the cylinder mounting mechanism; and a fitting recessed portion provided in one end portion of the cylinder case and capable of receiving the mouthpiece support section, the fitting recessed portion being defined by an inner peripheral wall part of the one end portion that has a wall thickness tapering so that a surface of the inner peripheral wall part slants gradually outwardly toward a distal end of the fitting recessed portion, whereby, when the cylinder case having the cassette gas cylinder accommodated therein is to be mounted to the cylinder mounting mechanism, the mouthpiece portion is automatically guided into coaxial alignment with the mouthpiece support section by the surface of the inner peripheral wall part functioning as a mounting guide surface.