Patent ID: 7124840

Claim:
An engine breaker comprising: a vertically extending cylindrical main body; a work member supported by a lower portion of the main body for up and down movement; an engine mounted to an upper portion of the main body and having an output shaft arranged to extend horizontally; and a striker incorporated in the main body for successively striking an upper end of the work member through rotation of a horizontally extending rotary shaft to which rotation output of the engine is transmitted; wherein the engine includes a housing supported by the main body via a resilient member, and a flexible coupling for absorbing vibration in a direction crossing the rotary shaft is interposed between the output shaft and the rotary shaft; wherein the flexible coupling comprises a vibration absorber made of a resilient material and interposed between the rotary shaft and an output transmitting portion provided at the output shaft of the engine for transmitting output to the rotary shaft; wherein an engine mount plate is provided for mounting the engine to the main body, the engine mount plate being provided with a bearing arranged between the side surface of the engine and the side surface of the main body; wherein the output transmitting portion has an end in a form of a boss fitted in the bearing and having an inner circumferential surface formed with a plurality of radically extending first projections; wherein the rotary shaft has an end formed with a plurality of axially extending second projections provided correspondingly to the first projections, each of the second projections being received in the boss end of the output transmitting portion and located between adjacent first projections; and wherein the vibration absorber includes a plurality of vibration absorbing portions each of which is arranged between a side surface of a respective one of the first projections and a side surface of the adjacent second projection in the boss end of the output transmitting portion.