Sensing and control system

Claim 2

A sensing and control system for controlling the operation of a machine comprising first and second timers arranged to actuate means for modifying the action of the machine, the first timer being arranged to actuate said means after the elapse of a first predetermined time period from the occurrence of a first given operating condition of the machine if a second given operating condition of the machine does not occur before said first time period elapses, and the second timer being arranged to actuate said means after the elapse of a second predetermined timer period from the occurrence of said second given operating condition if a third given operating condition of the machine does not occur before said second time period elapses, and sensing means for detecting the occurrence of said second and third operating conditions and preventing actuation of said means by the first timer when said second condition occurs within said first predetermined time period and by the second timer when said third condition occurs within said second predetermined time period.

Claim 3

A system according to claim 1 wherein the first timer is arranged to start timing in response to initiation of feeding movement of a workpiece by the machine and timing by the first timer is arrested in response to contact of said workpiece with a sensing element of the sensing means.

Claim 4

A system according to claim 1 wherein the second timer is arranged to start timing in response to contact of a workpiece fed by the machine with a sensing element of the sensing means and timing by the second timer is arrested in response to disengagement of said workpiece from said sensing element.

Claim 5

A system according to claim 1 wherein said machine includes means for feeding a workpiece through a predeteRmined distance within said first predetermined time period and means for performing an operation of said workpiece on completion of feeding thereof through said predetermined distance, completion of feeding of said workpiece through said predetermined distance constituting said second given operating condition of the machine, said system further including further sensing means for sensing feed movement of said workpiece in excess of said predetermined distance by a pre-selected amount and actuating said modifying means in response to sensing of said excess feed movement.

Claim 6

A system according to claim 1 wherein the modifying means actuated by each timer interrupts the machine feed at the end of the period at which the timer is set to time.

Claim 7

A sensing and control system for controlling the operation of a machine comprising a timer arranged to actuate means to modify the action of the machine after the elapse of a predetermined time period from the occurrence of a first given operating condition of the machine if a second given operating condition of the machine does not occur before said time period elapses, including sensing means for detecting the occurrence of said second operating condition and preventing actuation of said modifying means by the timer when said second condition is detected during said predetermined time period, said machine including means for feeding a workpiece through a predetermined distance within said predetermined time period, completion of feeding of said workpiece through said predetermined distance constituting said second given operating condition of the machine, said system further including sensing means for sensing feed movement of said workpiece in excess of said predetermined distance by a pre-selected amount and actuating said modifying means in response to sensing of said excess movement.

Claim 8

A sensing and control system for controlling the operation of a machine comprising a timer arranged to actuate means to modify the action of the machine after the elapse of a predetermined time period from the occurrence of a first given operating condition of the machine if a second given operating condition of the machine does not occur before said time period elapses, including sensing means for detecting the occurrence of said second operating condition and preventing actuation of said modifying means by the timer when said second condition is detected during said predetermined time period, said machine including means for feeding a workpiece through a predetermined distance within said predetermined time period, completion of feeding of said workpiece through said predetermined distance constituting said second given operating condition of the machine, said system further including sensing means for sensing feed movement of said workpiece in excess of said predetermined distance by a pre-selected amount and actuating said modifying means in response to sensing of said excess movement.