Digital fine-coarse rapid indexing motor control including means to sense shortest distance

Claim 1

In an indexing control device for controlling the rotation of a rotating body having at least ten spaced index positions by a motor so as to place a desired index position of said spaced index positions at a predetermined station, an improvement comprising; means identifying said index positions by applying specific identifying decimal numbers provided to each one of said index positions and coded by binary coded decimal elements, each of said numbers comprising a higher figure and a lower figure, said index positions of said rotating body being divided into a plurality of regions identified by the higher figures of said specific identifying decimal numbers; reading means operated by said binary coded decimal elements so as to produce an identifying signal in accordance with one of said index positions which is actually placed at said predetermined station; command circuit means capable of commanding a desired index position to be placed at said predetermined station; first discriminating circuit means including relays corresponding to the higher figures of said specific identifying decimal numbers which are present in accordance with said desired index position so as to discriminate the rotating direction of said rotating body in response to said identifying signal of the higher figure when the region containing said desired index position is different from the region containing an actual index position placed at said predetermined station; detecting circuit means connected to said command circuit means and said reading means for producing a detecting signal when the region containing said desired index position is identical with the region containing said actual index position; second discriminating circuit means which are preset in accordance with said desired index position for discriminating the rotating direction of said rotating body in response to said identifying signal of the lower figure of said specific identifying decimal numbers, said second discriminating circuit means starting the operation thereof according to said detecting signal; coincidence circuit means preset in accordance with said desired index position and operated in response to said identifying signal which produces a coincidence signal when said desired index position is placed at said predetermined station; and motor controlling means which is activated by said first and second discriminating circuit means for rotating said rotating body in the discriminated direction to index said desired index position into said predetermined station by the shorter rotatinG route and for stopping the rotation of said rotating body in response to said coincidence signal.