Digital positioning system
AssigneeBryant Grinder Corporation
InventorRoger L. Schroeder
Life of this patent
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Abstract
A lateral feed position system for a single slide grinder or the like wherein a wheel spindle is displaced between a sequence of preset end points. The end points are input from decade switches as position commands and compared to a current position count in a digital comparator unit. An oscillator is energized to apply up or down count signals to the comparator depending on the result of the comparison. The same signals are applied to a stepper motor. Actual displacement signals from a shaft angle encoder are compared to the position commands to advise a sequencer that the spindle is "in position" so that the next command can be input. Means are provided to adjust the actual position counts to compensate for wheel wear. Specific circuits are disclosed.
Claims11
A digital positioning system comprising:
- a bidirectional motor responsive to first pulses to move an output member through discrete increments;
- a source of digital pulses representing said increments said source having an add pulse output representing displacements in one direction and a substract pulse output representing displacements in the other direction;
- a plurality of individually settable input means for designating a plurality of sequentially selectable desired end positions of said output member, means for producing second pulses representing increments and direction of actual displacement thereof;
- first comparator means connected to the add and subtract pulse outputs and to the input means for sequentially comparing a net cumulative count of add and subtract pulses applied by the source to the motor with selected end position counts and controlling the flow of pulses from the source to equalize the net count with the selected end position count;
- and second comparator means for individually comparing the selected end position counts with actual pulse counts from the encoder to determine when the output member reaches the selected end position.
In a digital positioning system of the type having a bidirectional motor responsive to first and second pulse trains to move incrementally in opposite directions:
- a plurality of individually settable switches for selecting counts representing end positions to be achieved by said motor in a predetermined sequence;
- a control memory separate from said switches and programmed to establish said sequence, said control memory being operatively connected to the switches to select the switches for input conditioning as said sequence is advanced;
- counter/comparator means for compiling a count representing the net position change of said motor and for comparing said count to the end position count of the switch selected for input conditioning at any given time and for producing an output representing the magnitude and sense of difference therebetween;
- means connected to said counter/comparator means and responsive to the output therefrom to selectively apply first and second pulse trains to the motor until the counts coincide;
- and means responsive to a coincidence of said counts to advance said sequence.
Dependencies are inferred from the claim text.