In-line oscillating cam assembly

A portable power tool comprising:

• a housing;
• an implement having an oscillating power input;
• a motor supported upon the housing;
• a cam shaft having a longitudinal axis, the cam shaft rotatable about the longitudinal axis by the motor;
• a pair of eccentric drive cams longitudinally spaced apart from each other and mounted on the cam shaft eccentrically out of phase, the pair of drive cams having opposed circumferential chamfered surfaces oriented at an inclined angle relative a plane perpendicular to the longitudinal axis of the cam shaft;
• a follower shaft spaced apart from and parallel to the cam shaft;
• a cam follower longitudinally fixed to the follower shaft and extending between the pair of drive cams, the cam follower having a pair of opposed frustoconical follower-surfaces engaging the chamfered surfaces of the pair of drive cams, whereby rotating one of the cam shaft and follower shaft causes the other one of the cam shaft and follower shaft to axially oscillate, wherein one of the cam shaft and the follower shaft is coupled to the oscillating power input of the implement;
• a pair of eccentric balance cams longitudinally spaced apart from each other and from the pair of drive cams and mounted therewith on the cam shaft eccentrically out of phase, the balance cams having opposed circumferential chamfered balance-surfaces inclined relative to a plane between the balance cams located perpendicular to the longitudinal axis of the cam shaft;
• and
• a balance cam follower rotatable about the drive shaft and extending between the balance cams, the balance cam follower having a pair of opposed frustoconical balance surfaces engaging the chamfered balance-surfaces of the pair of balance cams so that the balance cam follower axially oscillates in a longitudinal direction opposite the cam follower to counter balance a reaction force generated by oscillation of the cam follower.

A portable power tool comprising:

• a housing;
• an implement having an oscillating power input;
• a motor supported upon the housing;
• a cam shaft having a longitudinal axis, the cam shaft rotatable about the longitudinal axis by the motor;
• a pair of eccentric drive cams longitudinally spaced apart from each other and mounted on the cam shaft eccentrically out of phase, the pair of drive cams having opposed circumferential chamfered surfaces oriented at an inclined angle relative a plane perpendicular to the longitudinal axis of the cam shaft;
• a follower shaft spaced apart from and parallel to the cam shaft;
• a cam follower longitudinally fixed to the follower shaft and extending between the pair of drive cams, the cam follower having a pair of opposed frustoconical follower-surfaces engaging the chamfered surfaces of the pair of drive cams, whereby rotating one of the cam shaft and follower shaft causes the other one of the cam shaft and follower shaft to axially oscillate, wherein one of the cam shaft and the follower shaft is coupled to the oscillating power input of the implement;
• a balance shaft spaced apart from and parallel to the drive shaft on a side opposite the follower shaft;
• and
• a balance cam follower rotatable about the balance shaft and extending between the pair of drive cams, the balance cam follower having a chamfered balance-surface engaging the chamfered surfaces of the pair of drive cams, whereby rotating the cam shaft further causes the balance cam follower to axially oscillate in a longitudinal direction opposite to that of the cam follower.