Patent ID: 6086502
Filing Date: 2000-07-11
Classification: B25F

Abstract:
A switching device of a reduction gear set coupled to and driven by a planetary gear system for driving an output tool, the switching device comprising:a casing defining an interior space having an inside surface on which an internal gear is formed, the casing also defining two opposite elongate slots; anda switching member received in the casing and movable between a first position and a second position, the switching member comprising:a cylindrical body forming an inner ring gear adapted to serve as a ring gear of the planetary gear system and engaging with planet gears of the planetary gear system and an outer ring gear which engages with the internal gear of the casing and thus prevents the switching member from rotation when the switching member is at the first position and disengages from the internal gear of the casing and thus frees the switching member to rotate when the switching member is at the second position,a driving member rotatably fit over the cylindrical body and being axially fixed thereto, the driving member having extensions projecting radially outward beyond the casing through and axially movable along the slots thereof, wherein by manually moving driving member, the switching member is moved between the first and second positions for changing output speed of the tool.