Turret indexing control circuit

Claim 2

A turret indexing system comprising a turret for indexing movement selectively to each of a plurality of turret indexing positions and having means for generating an over travel signal as the turret moves somewhat past each indexing position, a command register for registering digital commands with respect to the indexing positions of the turret, a position register incrementally responsive to successive station recognition pulses to count in a predetermined sequence, a comparator circuit connected to said command register and to said position register and responsive to a coincidence in the numbers storEd therein to generate a comparison signal, an all stop bistable circuit for supplying an all stop signal for causing interruption of the operation of the system, and a digital logic circuit connected with said means for generating said over travel signal to receive successive over travel signals therefrom during an indexing operation as the turret moves past successive indexing positions in moving from an initial indexing position to a desired new indexing position as represented by a digital command in said command register, said logic circuit being connected with said comparator to receive said comparison signal therefrom when the turret reaches the desired new indexing position, and being connected with said all stop bistable circuit, and said logic circuit being responsive to an over travel signal occurring after the occurrence of said comparison signal during an indexing movement to signal an error in the turret indexing operation since the turret has over traveled the desired new indexing position and being operable in response to such over travel of the desired new indexing position to actuate said all stop bistable circuit thereby causing interruption of the operation of said system.

Claim 3

In a turret indexing system including a command register for registering commanded indexing positions for the turret, a position register for registering a number in accordance with a present position of the turret, but susceptible to operation out of synchronization with the actual turret position, and a comparator circuit connected to said command register and to said position register and responsive to a lack of coincidence of numbers registered therein to assist in controlling an indexing operation, the improvement comprising a rotary turret for indexing movement selectively to each of a plurality of turret indexing positions and having turret initial position switch means actuated each time the turret reaches a predetermined initial turret indexing position in its path of movement, and a digital initializing circuit having an input for receiving a digital initializing signal in advance of positioning operations for insuring the synchronization of the actual turret position with the position thereof shown by said position register and responsive to said digital initializing signal for automatically indexing said turret to said predetermined initial turret indexing position under the control of said turret initial position switch means and operable to insure that the position of the turret shown by the position register corresponds to said predetermined initial turret indexing position regardless of whether the position shown by said position register corresponded to the actual turret position prior to receipt of said digital initializing signal, said digital initializing circuit comprising a turret indexing control circuit bypassing said comparator circuit and operable to initiate indexing movement of the turret in response to said digital initializing signal independently of the condition of said comparator circuit, said turret indexing control circuit controlling indexing movement during automatic indexing of said turret in response to said digital initializing signal and being connected with said initial position switch means and responsive to actuation of said initial position switch means during automatic indexing of said turret to interrupt automatic indexing of said turret when the turret reaches said predetermined initial turret indexing position.

Claim 4

In a turret indexing system including a command register for registering commanded indexing positions for the turret, a position register for registering a number in accordance with a present position of the turret, but susceptible to operation out of synchronization with the actual turret position, and a comparator circuit connected to said command register and to said position register and responsive to a lack of coincidence of numbers registered therein to assist in controlling an indexing operation, the improvement comprising a rotary turret for indexing movement selectively to each of a plurality of turret indexing positions and having turret initial position switch means actuated each time the turret reaches a predetermined initial turret indexing position in its path of movement, and a digital initializing circuit having an input for receiving a digital initializing signal in advance of positioning operations for insuring the synchronization of the actual turret position with the position thereof shown by said position register and responsive to said digital initializing signal for automatically indexing said turret to said predetermined initial turret indexing position under the control of said turret initial position switch means and operable to insure that the position of the turret shown by the position register corresponds to said predetermined initial turret indexing position regardless of whether the position shown by said position register corresponded to the actual turret position prior to receipt of said digital initializing signal, said digital initializing circuit comprising a turret indexing control circuit bypassing said comparator circuit and operable to initiate indexing movement of the turret in response to said digital initializing signal independently of the condition of said comparator circuit, said turret indexing control circuit controlling indexing movement during automatic indexing of said turret in response to said digital initializing signal and being connected with said initial position switch means and responsive to actuation of said initial position switch means during automatic indexing of said turret to interrupt automatic indexing of said turret when the turret reaches said predetermined initial turret indexing position.

Claim 5

The turret indexing system of claim 2 with said turret having means for generating an overtravel signal as the turret moves somewhat past each indexing position, and means responsive to an overtravel signal occuring after the turret reaches a commanded indexing position to signal an error in the turret indexing operation.

Claim 6

The turret indexing system of claim 2 wherein said turret indexing control circuit comprises a bistable circuit responsive to a digital initIalizing signal which is also utilized to signal that a tool change is to take place, said bistable circuit being responsive to said initializing signal to assume one of its stable conditions to produce turret indexing movement, and said bistable circuit having a second input controlled by said turret initial position switch means whereby the bistable circuit is shifted to its second stable condition in response to the turret reaching said predetermined initial turret indexing position to discontinue indexing movement of the turret.