| 摘要 |
A number of cam-operated devices such as power tools 10 are described, the tools having rotary drive means 24 for rotating a drive shaft 36 having a cylinder cam 42 mounted thereon. A pair of cam followers 54 are located within a cam track 44 provided on the cam member 42, such that rotation of the cam 42 causes axial movement of the cam followers 54, which may be attached to a drive shaft 48 and a tool bit 12. A range of shapes of cam track 44 are described, each of which is non-sinusoidal in shape. Various embodiments of the invention provide non-sinusoidal cam tracks having forward or rearward throw sections which are respectively steeper, shorter, or provide greater acceleration of the cam followers than sinusoidal cam tracks of equivalent wavelength and amplitude. Related piston and cylinder devices and reciprocal drive means are also described.
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