Centering device

Claim 1

A centering device comprising: a centering pointer comprising a cylindrical hollow holder having two ends and within which a needle member having a lower point is slidably coaxially held, and extends out of the first end of said holder, said needle member being resiliently urged by a spring means to extend out of said holder, said spring being disposed within the space defined by the hollow holder, a plug located at the other end of said holder and the needle member, a lever mounted onto said needle member and extending outwardly through a slot formed on said hollow holder, a measuring device for sensing the displacement of said lever, said hollow holder adapted to be coaxially detachably mounted onto the spindle of a manufacturing machine; and a truncated cylindrical centering block provided with a cylindrical surface having a center axis, and a L-shaped cutaway having two planar surfaces forming a 90 degree angle therebetween, at least one of said surfaces passing through said center axis; said centering block adapted to be mounted on a workpiece with said one surface abutting a side edge of the workpiece to be aligned with the center axis of said centering pointer, said alignment being attained by causing said needle member of said centering pointer to move axially by moving said centering block with the workpiece in a direction perpendicular to the center axis of said centering pointer so that said lower point of said needle member contacts and moves along said cylindrical surface with the upward movement of said needle member causing said lever to actuate the measuring device which thereby indicates that alignment has been attained.