US 5,503,200 AGranted

Shaft tapering device

OwnerMichael F. Leainventor

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Abstract

A shaft tapering device having a body block with a transverse borehole through which the shaft to be tapered is introduced. A recess in the top of the body block intersects the borehole, forming an aperture into which a cutting blade extends substantially tangential to the curvature of the borehole. A cradle attached to the body block includes a pair of parallel wing-like members spaced apart by spreaders at each end of the wings, which are pivotably mounted to the body block. Each wing has a notch formed in the upper edge thereof that is semicircular in the deepest part and on pivoting the wings the deepest part of the notches can be substantially aligned with the borehole. On holding a handle attached to the body block, pivoting the wings during rotation of a workpiece, and moving the device laterally, the work piece is quickly and controllably tapered, the notches in the wings of the cradle bringing the work piece to the cutting blade with the work piece substantially centered under the cutting edge at all times. A portable kit combines the tapering device with a guide frame having a longitudinal way joining a head stock with a tail stock, and with a tapering template extending between the two. A template follower attached to the forward spreader of the cradle rides on the template and automatically pivots the cradle as the device is slid along the way as the work piece is rotated by a drill motor mounted on the head stock.

A shaft tapering device comprising:

a body block having a top side, a bottom side, a front side, a rear side and lateral sides;
a guiding cradle pivotably mounted on the lateral sides of the body block and having front and rear ends;
and
a handle attached to or adjacent the rear side of the body block;
the body block having a transverse borehole adjacent the front side for receipt of a work piece to be turned and an aperture extending forwardly and downwardly from the top side to intercept the borehole, the aperture being adapted for mounting a cutting blade to extend operatively slightly into the borehole;
the guiding cradle having two arms, each the same length and somewhat longer than the body block and being joined spaced apart by a spreader element at each end, the guiding cradle being pivotably mounted by means of the arms each being attached pivotably to a respective lateral side of the body block at a point between the borehole and the rear side of the body block and about at the level of the top of the borehole, and spaced from the nearest edge of the borehole a distance about equal to the diameter of the borehole;
the arms each being provided with a rearwardly inclined J-shaped support notch at about their mid-length, each notch at its deepest part being nearly semicircular and the defining edge of each notch closest to the front side of the body block extending upwardly flared slightly away from a line tangential to the semicircular deepest part and crossing a line running through the pivotal attachment point and the top of the borehole at an angle of almost 90 degrees, while on the other side of the deepest part the opposing edge flares away, curving slightly from the tangential line and crossing the said line running through the pivotal point at an angle between about 40 and about 45 degrees, the deepest part of each notch having about the same diameter as the borehole of the body block and being substantially alignable therewith on pivoting the arms of the guiding cradle.

4 more elements

Abstract

Claims20