Interruptable numerical contouring control system with return to path safeguards

In a numerical path control system for controlling the movements of a member along plural axes, and including control means responsive to a program of successive blocks of command signals for automatically moving the member seriatim along respective corresponding path segments, the improvement comprising

• a. means responsive to a feedhold signal for stopping the member at a random point along the path, and for interrupting operation of said control means,
• b. means for storing signals representing the axis coordinates of the stopping point of the member each time it halts in response to a feedhold signal,
• c. means effective after the member has so stopped for moving the member under manual control and independently of said program command signals to various desired locations displaced from said stopping point,
• d. means for producing displacement signals which represent the axis component displacements between said stopping point and any location in which the member resides after movement thereof by said means (c), and
• e. means operative only after said axis displacement signals have been reduced substantially to zero for causing said control means to resume operation.

In a numerical path control system for controlling the movements of a member along plural axes, said system including

• a. a source of block command signals controllable upon demand to deliver successive blocks of signals defining successive corresponding path segments,
• b. control means responsive to each block of command signals for moving said member along the corresponding defined path segment, and
• c. means responsive to completion of one segment of movement for transferring from said source (a) to said control means (b) the next successive block of command signals, so that said member is moved seriatim through a program of successive path segments, the improvement comprising
• 1. means for producing a feedhold signal at random instants while said member is being moved by said control means (b),
• 2. means responsive to a feedhold signal for stopping said member at a random point along the path and interrupting the successive operations of said means (b) and (c),
• 3. means for storing signals representing the axis coordinates of the stopping point of said member each time it is so stopped,
• 4. means effective after said member has been so stopped for moving said member independently of said means (a) and (c) to various desired locations displaced from said stopping point by jogging type movements which are executed in succession and in any desired number,
• 5. means for creating and storing signals which represent the axis component displacements between any said location at which said member resides and said stopping point,
• 6. means responsive to a restart signal for causing said system means (b) and (c) to resume their interrupted operation, and
• 7. means for rendering said means (6) ineffective until said axis component signals have been reduced to zero in consequence of said member being returned to the last of said stopping points.

In a numerical control system for controlling the movements of a member along plural axes to execute a pre-programmed path, said system including

• a. control means responsive to a block of command signals for moving said member simultaneously through axis components defined by such signals and making up a resultant path segment,
• b. means for supplying a program of successive blocks of command signals to said control means (a) so that the member is moved seriatim through successive connected segments constituting a programmed path, and
• c. means responsive to the appearance and continued existence of a cycle start signal for initiating and continuing the successive cyclic operation of said means (a) and (b), the improvement comprising, in combination,
• 1. means for producing a cycle start signal,
• 2. means for producing a feedhold signal at random instants,
• 3. means responsive to said feedhold signal for turning off said means (1) and causing said member to halt at a random stopping point on the path,
• 4. means for creating and storing signals which represent the axis coordinates of said stopping point each time the member is so stopped,
• 5. means for moving said member independently of said means (b) to various desired locations displaced from said stopping point,
• 6. means for producing signals which substantially continuously designate axis coordinates of said member as it resides in said various locations, and
• 7. means for preventing said means (1) from being turned on unless the signals from said means (6) are in agreement with the signals from said means (4).

In a numerical control system for moving a member simultaneously along plural axes to execute a programmed path, said system including

• a. control means responsive to a program of successive blocks of command signals for automatically moving the member seriatim along respective corresponding path segments, the improvement comprising
• 1. means responsive to a feedhold signal for interrupting the operation of said control means (a) and stopping the member at a random point along the path,
• 2. means for storing signals representing the axis coordinates of the member's stopping point each time it halts in response to a feedhold signal,
• 3. means effective after said member has so stopped for moving the member under manual selection control to various successive desired locations displaced from said stopping point,
• 4. means for producing signals representing the axis coordinates of the location of said member as and after it is moved by said means (3),
• 5. operator-actuated means for causing said control means (a) to resume operation,
• 6. means for comparing said stopping point coordinate signals from said means (2) with the location coordinate signals from said means (4), and
• 7. means controlled by said means (6) for rendering said operator-actuated means (5) ineffective unless and until said comparing means (6) finds substantially equality of the respective compared signals.

In a numerical control system for controlling the movements of a member simultaneously along plural axes to execute a programmed path, said system including

• a. control means responsive to a program of successive blocks of command signals for automatically moving the member seriatim along respective corresponding path segments, the improvement comprising
• 1. means responsive to a feedhold signal for interrupting the operation of said control means (a) and stopping the member at a random point along the path,
• 2. means for storing signals representing the axis coordinates of the stopping point of the member each time it halts in response to a feedhold signal,
• 3. means effective after the member has so stopped for moving the member under manual selection control to various successive desired locations displaced from said stopping point,
• 4. means responsive to said stopping point coordinate signals for producing signals which represent the axis component displacements between said stopping point and any location in which the member resides after movement thereof by said means (3),
• 5. a restart switch and means responsive to momentary actuation thereof fore causing said control means (a) to resume operation, and
• 6. means for disabling said cycle start switch responsive means so long as any of the axis component displacement signals from said means (4) represents a value other than substantially zero.

In a numerical control system for moving a member simultaneously along plural axes to follow a pre-programmed path, said system including

• a. control means responsive to a block of command signals for moving the member along a corresponding path segment having axis components directly or indirectly represented by such command signals, and
• b. means for supplying a program of blocks of command signals sequentially to said means (a) to cause movement of the member seriatim along successive segments of a programmed path, the improvement comprising
• 1. means for producing a feedhold signal at random instants in time while said means (a) and (b) are operating,
• 2. means responsive to said feedhold signal for interrupting the sequential operation of said means (a) and (b) and stopping said member at a random point on said path,
• 3. means for storing signals representing the axis coordinates of the stopping point of the member after it has been so stopped,
• 4. means effective after the member has been so stopped for moving the member under manual selection control to various desired locations displaced from said stopping point,
• 5. means responsive to said means (3) for producing signals which represent the axis component displacements between said stopping point and the location in which said member resides after movement thereof by said means (4),
• 6. means for producing a restart signal,
• 7. means responsive (i) to said restart signal and (ii) said signals from said means (5) for moving the member through said axis component displacements back to said stopping point, and
• 8. means responsive to the completion of operation of said means (7) for restoring said means (a) and (b) to normal sequential operation.

In a numerical control system for moving a member simultaneously along plural axes to follow a pre-programmed path, said system including

• a. control means responsive to a block of command signals for moving the member along a corresponding path segment having axis components directly or indirectly represented by such command signals, and
• b. means for supplying a program of successive blocks of command signals sequentially to said means (a) to cause movement of the member seriatim along successive segments of a programmed path,
• the improvement comprising
• 1. means for producing a feedhold signal,
• 2. means responsive to the feedhold signal for interrupting the operation of said means (a) and stopping the member at a random point on said path, and for interrupting the successive supplying by said means (b),
• 3. means for storing signals representing the axis coordinates of the stopping point of the member after it has been so stopped,
• 4. means effective after the member has been so stopped for moving the member under manual selection control to various desired locations displaced from said stopping point,
• 5. means for producing signals which represent the axis coordinates of the location in which the member resides after movement thereof by said means (4),
• 6. means for producing a restart signal,
• 7. means responsive to said restart signal for supplying to said means (a) an artificial block of command signals representing the axis component displacements between the coordinates represented by the signals from said means (3) and the coordinates represented by the signals from said means (5), and
• 8. means responsive to the execution of said artificial block of command signals for restoring said means (a) and (b) to normal sequential operation.

In a numerical control system for moving a member simultaneously along plural axes to execute a programmed path, said system including

• a. control means responsive to a block of command signals for moving the member along a corresponding path segment having axis components directly or indirectly represented by such signals, and
• b. means for supplying successive ones of a program of blocks of command signals to said control means (a) to cause movement of said member seriatim along successive segments of the programmed path.
• the improvement comprising
• 1. means for interrupting the sequential operation of said means (a) and (b) and stopping the member at a random point on the path,
• 2. means effective after said member has been so stopped for moving the member under manual selection control to various desired successive locations displaced from said stopping point,
• 3. means for creating and storing signal sets representing the axis components through which said member is moved each time it is changed from one location to another by operation of said means (2), such signal sets being designatable N.sub.1, N.sub.2. . . N.sub.n in the order of their storage,
• 4. means for creating a restart signal,
• 5. means responsive to the restart signal for responding to said stored signal sets in the reverse order N.sub.n. . . N.sub.2, N.sub.1 including means responsive to each such signal set for moving the member reversely through axis component distances corresponding to the components represented by the signals of such set, and
• 6. means for restoring said means (a) and (b) to normal sequential operation after the return motion of said member according to the signal set N.sub.1 has been completed.

In a numerical control system for moving a member simultaneously along plural axes to execute a programmed path, said system including

• a. control responsive to a block of command signals for moving the member along a corresponding path segment having axis components directly or indirectly represented by such command signals, and
• b. means for supplying successive ones of a program of blocks of command signals to said control means (a) to cause movement of said member seriatim along successive segments of the programmed path,
• the improvement comprising
• 1. means for interrupting the sequential operations of said means (a) and (b) and stopping the member at a random point on the path,
• 2. means effective after said member has been so stopped for moving the member under manual selection control to various desired successive locations displaced from said stopping point,
• 3. means for creating and storing signal sets directly or indirectly representing the axis components through which said member is moved each time it is changed from one location to another by operation of said means (2), such signal sets being designatable N.sub.1, N.sub.2. . . N.sub.n in the order of their storage,
• 4. means for creating a restart signal,
• 5. means responsive to the restart signal for supplying said stored signal sets in reverse order N.sub.n. . . N.sub.2, N.sub.1 as artificial blocks of command signals to said control means (a), whereby the latter moves the member reversely along segments identical to, and in the reverse order of, the segments through which such member was moved by operation of said means (2), and
• 6. means for restoring said means (a) and (b) to normal sequential operation after the return movement according to the signal set N.sub.1 has been completed.