Apparatus for maintaining a constant surface speed of a rotating work piece being cut by a moving cutting tool

Abstract

An apparatus for maintaining a constant surface speed of a rotating work piece being cut by a moving cutting tool, comprising means for storing a first signal representing a binary coded decimal number which is further representative of the product of the desired constant surface speed of the work piece and a conversion constant. The apparatus is further comprised of a shift register for receiving a second signal representing a binary coded decimal number which is further representative of the current radial dimension of the work piece being cut, and means for storing a third signal representing a binary coded decimal number initially representative of an assumed rotational speed of the work piece. Means for arithmetically multiplying the binary coded number representative of the radial dimension of the work piece by the binary coded number representative of the assumed rotational speed of the work piece is also provided, along with a means for storing a fourth signal representing a binary coded decimal number which is further representative of the product of the radial dimension of the work piece and the rotational speed of the work piece. Further provided is a means for comparing the first signal representing the binary coded decimal number which is representative of the product of the desired constant speed of the work piece and the conversion constant with the fourth signal representing the binary coded decimal number which is representative of the product of the radial dimension of the work piece and the assumed rotational speed of the work piece, and for providing a fifth signal to adjust the binary coded decimal number representative of the assumed rotational speed of the work piece until the compared first and fourth signals are made approximately equal, at which time a sixth signal representing a final binary coded decimal number representative of the required rotational speed of the work piece is generated to control the speed of a motor that drives a spindle which holds the work piece.

Dependencies are inferred from the claim text.