Adjustable stroke reciprocating mechanism for a power tool
AssigneeSkil Corporation
InventorsDieter B. Meyer, Mark S. Talesky
Life of this patent
Estimating the term…
Abstract
The ram of the reciprocating saw is driven by a scotch yoke mechanism. A planetary gear system consisting of a ring gear and an idler gear imparts an elliptical or linear path of movement to the pin forming part of the scotch yoke mechanism. The ring gear may be adjustably positioned for changing its relationship relative to the idler gear thereby varying the orientation of the elliptical or linear path of movement of the drive pin for varying the stroke of reciprocation of the ram which is connected to the saw blade holder. Actuation of the ring gear to its desired position automatically causes the foot plate of the saw to be located in its desired position for the selected stroke of movement.
Claims12
In a reciprocating saw of the type having a housing containing a motor for reciprocating a blade holder which is adapted to mount a saw blade, the improvement comprising:
- (a) a mechanism for converting oscillating movement to reciprocal movement including a crank pin engaged with a reciprocating member, said reciprocating member being connected to said blade holder;
- (b) a planetary gear system including a ring gear and an idler gear in meshing engagement with each other, said gears being configured such that there is a 2:1 ratio between the ring gear and the idler gear;
- (c) said crank pin being eccentrically mounted on said idler gear;
- (d) a rotary drive member connected to said motor, said rotary drive member eccentrically carrying a drive pin which is concentric with said idler gear and which rotatably mounts the latter on the drive member such that upon rotation of the drive member said drive pin will be moved in a circular path causing said idler gear to be rotated about the axis of said drive pin as the idler gear meshes with the stationary ring gear and also causing said crank pin to be moved in an oscillatory path as the idler gear rotates relative to the ring gear;
- and
- (e) actuator means connected to said ring gear for shifting said ring gear about its central axis for altering the path of said crank pin thereby to vary the stroke of said blade holder.
In a reciprocating drive apparatus for a power tool, a blade holder adapted for connection with a cutting member, a mechanism for converting oscillating movement to reciprocal movement including a crank pin engaged with a reciprocating member connected with said blade holder for reciprocating the latter, a planetary gear system including a ring gear and an idler gear in meshing engagement with each other, said gears being configured such that there is a 2:1 ratio between the ring gear and the idler gear, said crank pin being eccentrically mounted on said idler gear, a rotary drive member eccentrically carrying a drive pin which is concentric with said idler gear and which rotatably mounts the latter can the drive member such that upon rotation of the drive member said drive pin will be moved in a circular path causing said idler gear to be rotated about the axis of said drive pin as the idler gear meshes with the stationary ring gear and also causing said crank pin to be moved in an oscillatory path as the idler gear rotates relative to the ring gear, and actuator means connected to said ring gear for shifting said ring gear about a central axis for altering the path of said crank pin thereby to vary the stroke of said blade holder.
Dependencies are inferred from the claim text.