Dual-cycle cam grinding machine with electrical pulse operated wheel feed

Claim 1

Wheel feed control apparatus for a grinding machine having a rotatable grinding wheel for grinding the surface of a workpiece, said apparatus comprising wheel advance means for moving said grinding wheel toward and away from the workpiece during rotation of the grinding wheel, said wheel advance means including support means for rotatably supporting said grinding wheel and motor means for effecting movement of said support means between a plurality of operating positions including a rough reset preset position in which said grinding wheel is spaced apart from a rough outer surface of the workpiece, a rough size preset position in which said grinding wheel is disposed in engagement with the outer surface of the workpiece when the workpiece has a preselected rough size, a finish reset preset position in which said grinding wheel is spaced apart from the outer surface of the workpiece when the workpiece has the preselected rough size, and finish size preset position in which said grinding wheel is disposed in engagement with the outer surface of the workpiece when the workpiece has a preselected finished size, a step form output operator for said motor means constructed and arranged to respond to an electrical pulsating input signal, first electrical pulse generator means for generating electrical pulses at any one of a plurality of pulse rates, means for selecting desired one of said plurality of pulse rates, selector means connected with said first pulse generator means and step operator to effect operation of said motor means as a function of a selected frequency and number of the applied pulses thereby producing a selected rate and number of incremental wheel advance movements, to operate said wheel advance means on open loop control to effect movement of said support means between said rough reset preset position, rough size preset position, finish reset preset position and finish size preset position, logic control means for effecting operation of said motor means to automatically move said support means through a plurality of operating cycles which includes movement of said support means from the rough reset preset position To the rough size position at a speed corresponding to a first pulse rate to rough grind the workpiece and to effect subsequent movement of said support means from the finish preset reset position to the finish size preset position at a speed corresponding to a secnd pulse rate which is slower than said first pulse rate to finish grind the workpiece, said logic control means including counter means for counting the pulses produced by said first electrical pulse generator and means for presetting said pulse counting means to count members of pulses corresponding to movement of said wheel support means to said rough reset preset position, said rough size preset position, said finish reset preset position and said finish size preset position, manual control means for effecting manual operation of said logic control means to operate said motor means and move said wheel support means between selected ones of said plurality of positions. said manual control means being operatively connected with said logic control means to effect operation of said motor means and movement of said wheel support means between selected ones of said plurality of positions in response to input signals transmitted from said manual control means to said logic control means, and manual/automatic switching means for selectively setting said logic control means to selectively operate in manual and automatic modes.