Bacon & Thomas
Rotate percussion hammer/drill shift device
 A rotate percussion hammer/drill shift device suitable for hand drill is provided. It is disposed at an output spindle of a drill to provide the drill with a percussion function. It further comprises at least a stationary percussion cam, an output shaft which is connected to the output spindle of the drill in a coaxial manner wherein said output shaft can be selectively moved to an working position from a normal position, this output shaft further includes a rotary cam by which the output shaft may rotate synchronously with the spindle of the drill, and a clutch mechanism which retains the output in the normal position and permits the output to be moved to a working position. When the output shaft is moved to the working position, the percussion cam is in contact with the rotary cam which is rotating such that the rotary cam generates a periodical hammer movement in the axial direction. Consequently, the output shaft is provided with a hammer movement. By this arrangement, the drill can be readily mounted with the present invention to improve the functions of the drill. 
A B
A62C B25F
inventional inventional
Yueh
Chen