Power tool
OwnerHugh E. Fisherinventor
Life of this patent
Estimating the term…
Abstract
The invention provides a portable power tool which is lightweight and convenient to use by the general public in any of its various forms, as a wallpaper stripper, a paint scraper or a cold chisel up to a power spade. The tool comprises a housing (12), a drive, an electric motor (14,160) adapted to drive at least one selected tool bit (4,56,62,64,66,68) mounted on an output shaft (44) moving in a reciprocating axial manner. Conveniently the drive may be a linear motor (160) or if used with a cam device, a rotary motor (14). The cam device may be a cylinder cam (32) provided with a sinusoidal cam track (34).
Claims10
A portable power tool powered by associated drive means and comprising a housing, and a mounting arrangement for operably coupling an output shaft to an element, such as a selected one of a plurality of interchangeable tool bits, to which reciprocal axial movement is to be imparted, said housing including an output arrangement for driving said output shaft in a reciprocal axial movement to correspondingly drive said element, said output arrangement including a cylinder cam mounted for rotation with a drive shaft rotationally driven by said drive means, said cam which is received within a hollow portion of said housing, comprising a cylindrical body having circumferential outer surface, a continuous sinusoidal recessed groove being formed in said outer surface at a position spaced from edge portions of said surface, said groove providing a sinusoidal cam track and cam follower means in the forms of at least two studs, struts or bosses mounted so as to project inwardly with respect to said housing, said cam follower means being capable of running in said cam track to impart said reciprocal motion to said output shaft.
A portable power tool powered by associated drive means and comprising a housing, and a mounting arrangement for operably coupling an output shaft to an element, such as a selected one of a plurality of interchangeable tool bits, to which reciprocal axial movement is to be imparted, said housing including an output arrangement for driving said shaft in a reciprocal axial movement to correspondingly drive said element, wherein said output arrangement includes a cylinder cam mounted for rotation with a drive shaft rotationally driven by said drive means, said cam being received within a hollow portion of said housing and provided with a sinusoidal cam track extending around its circumferential surface, and cam follower means in the form of at least two studs, struts or bosses mounted so as to project, and wherein said output shaft comprises two shaft portions, each of said shaft portions comprising two diametrically opposed extension portions, each of the four extension portions being provided with one of four of said studs, struts or bosses forming said cam follower means, and wherein the four studs, struts or bosses are arranged equidistantly around the cam track so that each of the two shaft portions partake of lengthwise reciprocating movement in opposed direction to the other, and securing means provided on each shaft portion for securing one of said tool bits.
Dependencies are inferred from the claim text.