Gear shifting speed change apparatus for a rotary electric tool
AssigneeMatsushita Electric Works, Ltd.
InventorsIchiro Kishi, Hisao Nakagawa
Life of this patent
Estimating the term…
Abstract
A gear shifting speed change apparatus for a rotary electric tool such as a drill having an electric motor driving a first pair of unequal diameter pinion gears which are in continuous driving engagement with a second pair of pinion gears. The gears of second pair are independently mounted next to each other for free rotation on a shaft having an axial keyway. An axially sliding key is manually shifted to engage either one, but not both, of the second pair of gears by means of a pair of projections extending radially outwardly from the sliding key, one projection being axially outside the outer face of each gear and engageable with a recess in the outer face of the adjacent gear.
Claims8
A gear shifting speed change apparatus for a rotary electric tool comprising:
- a shaft having an axially extending keyway therein with a gear changing slide mounted for axial movement in said keyway;
- said gear changing slide having a pair of axially spaced apart projections which extend radially outwardly beyond an outer periphery of said shaft;
- a pair of speed change gears mounted on said shaft and freely rotatable in relation thereto, an axial distance between axially outer faces of said gears being less than an axial distance between said slide projections;
- means to limit axial movement of said gears in relation to said shaft;
- at least one axially inwardly extending recess on each said gear outer face;
- means for axially sliding said gear changing slide in said keyway by using spring force so as to engage a recess of one of said gears and secure it for rotation with said shaft.
Dependencies are inferred from the claim text.