Automatic plant shutdown equipment

Claim 2

Control equipment for industrial plant operating from a main power source and having a first control operable to connect said plant to said main power source and a second control operable at intervals during the working of said plant, said equipment comprising: a first detector coupled to detect the operation of said first control and operable to provide an output indicative thereof; a second detector coupled to detect the operation of said second control and operable to provide an output indicative thereof; a timer unit, coupled to receive said outputs from said first and second detectors and comprising a first timer operable to commence a first timing operation in response to the receipt of said output from said first detector and in response to the receipt of said indication from said second detector, and operable to provide a first output indicative of said first timing operation not having endured for longer than a first predetermined period; a first relay switch, operable to connect said plant to said main power source if and only if said timer unit is in the course of providing said first output, said first predetermined period being longer than the maximum interval between successive operations of said second control, whereby, if said plant is being worked and said second control is being operated, said plant remains connected to said main power source but if said equipment ceases to be worked and said second control ceases to be operated, said plant is shut down by disconnection from said main power source.

Claim 3

Control equipment according to claim 1 for use where said plant is operable to transfer material between a first portion of said plant and a second portion of said plant, said equipment comprising; a sensor coupled to detect the transfer of said material between said first and second portion of said plant and operable to provide an output indicative of said transfer, said timer unit being coupled to receive said output from said sensor and comprising a second timer operable in response to the receipt of said output from said sensor to initiate a second timing operation, said timer unit being operable to provide a second output indicative of said second timing operation having been uninitiated for less than a second predetermined period, said second timing operation also being initiable in response to the receipt of said output from said first detector and in response to the receipt of said output from said second detector, and said equipment further comprising a second relay switch operable to connect said second portion of said plant to said main power source if and only if said timer unit is in the course of providing said second output, said second predetermined period being shorter than said first predetermined period, whereby said second portion of said plant is shut down independently of said first portion of said plant if said first portion of said plant ceases to transfer said material thereto and whereby said second portion of said plant is powered-up whenever said first portion of said plant is worked once more or is powered-up.

Claim 4

Control equipment according to claim 2, wherein said output from said sensor is repetitive, and wherein said second timing operation is initiable upon each receipt of said repetitive output, said second predetermined period being longer than the maximum period between successive repetitions of said sensor output.

Claim 5

Control equipment according to claim 1, wherein said first timer comprises: a first clock source operable to provide a first repetitious series of clock pulses of a first fixed period, a first counter, coupled to receive said first clock pulses, operable to increment a first count upon the receipt of each one of said first clock pulses, and operable to have said first count reset upon receipt by said timer unit of said output from said first detector or of said output from said second detector, a first binary number source operable to provide a first binary number equal to the number of times that said first predetermined period is greater than said first fixed period, and a first numerical comparator, coupled to receive said first count from said first counter and to receive said first binary number, operable to provide a first output indicative of said first count being less than or equal to said first binary number, and operable to provide a second output indicative of said first count being greater than said first binary number, where said first output of said first numerical comparator is coupled as said first output of said timer unit and where said second output of said first numerical comparator is coupled to inhibit the further provision of said first clock pulses to said first counter.

Claim 6

Control equipment according to claim 2, wherein said first timer comprises: a first clock source operable to provide a first reptitious series of clock pulses of a first fixed period, a first counter, coupled to receive said first clock pulses, operable to increment a first count upon the receipt of each one of said first clock pulses, and operable to have said first count reset upon receipt by said timer unit of said output from said first detector or of said output from said second detector, a first binary number source operable to provide a first binary number equal to the number of times that said first predetermined period is greater than said first fixed period, and a first numerical comparator, coupled to receive said first count from said first counter and to receive said first binary number, operable to provide a first output indicative of said first count being less than or equal to said first binary number, and operable to provide a second output indicative of said first count being greater than said first binary number, where said first output of said first numerical comparator is coupled as said first output of said timer unit and where said second output of said first numerical comparator is coupled to inhibit the further provision of said first clock pulses to said first counter.

Claim 7

Control equipment according to claim 5, wherein said second timer comprises: a second clock source operable to provide a second repititious series of clock pulses of a second fixed period, a second counter, coupled to receive said second clock pulses, operable to increment a second count upon the receipt of each one of said second clock pulses, and operable to have said second count reset upon receipt by said timer unit of said output from said sensor, of said output from said first detector or of said output from said second detector, a second binary number source operable to provide a second binary number equal to the number of times that said second predetermined period is greater than said second fixed period, and a second numerical comparator, coupled to receive said second count from said second counter and to receive said second binary number, operable to provide a first output indicative of said count being less than, or equal to, said second binary number, and operable to provide a second output indicative of said second count being greater than said binary number, where said first output of said second numerical comparator is coupled as said second output of said timer unit and where said second output of said second numerical comparator is coupled to inhibit the further provision of said second clock pulses to said second counter.

Claim 8

Control equipment according to claim 6, wherein said main power source comprises an electrical supply main, wherein said first control comprises a first electrical switch, wherein said second control comprises a second electrical switch and wherein said first relay switch comprises an electrically-operable relay for controlling the connection of said electrical supply main to said plant in concert with said first control.

Claim 9

Control equipment according to claim 7, wherein said first detector comprises a first auxiliary pair of contacts on said first switch, and wherein said second detector comprises a second pair of auxiliary contacts on said second switch.

Claim 10

Control equipment according to claim 8, wherein said second relay switch comprises an electrically-operable relay for controlling the connection to said second portion of said plant in concert with said first control and said first relay switch.

Claim 11

Control equipment according to claim 9 for use where said plant is a printing plant.

Claim 12

Control equipment according to claim 10, wherein said first portion of said plant comprises printing equipment, wherein said second portion of said plant comprises a paper take-up apparatus, and wherein said material for transfer between said first portion and said second portion of said plant is a moving paper web.

Claim 13

Control equipment according to claim 11, wherein said moving paper web comprises a plurality of regularly spaced holes longitudinally disposed therein, and wherein said sensor is an optical sensor for sensing said holes.

Claim 14

Control equipment according to claim 4 wherein said main power source comprises an electrical supply main, wherein said first control comprises a first electrical switch, wherein said second control comprises a second electrical switch, and wherein said first relay switch comprises an electrically-operable relay for controlling the connection of said electrical supply main to said plant in concert with said first control.

Claim 15

Control equipment according to claim 13, wherein said first detector comprises a first auxiliary pair of contacts on said first switch, and wherein said second detector comprises a second pair of auxiliary contacts on said second switch.

Claim 16

Control equipment according to claim 14 for use where said plant is a printing plant.

Claim 17

Control equipment according to claim 3, wherein said first timer comprises: a first clock source operable to provide a first repetitious series of clock pulses of a first fixed period, a first counter, coupled to receive said first clock pulses, operable to increment a first count upon the receipt of each one of said first clock pulses, and operable to have said first count reset upon receipt by said timer unit of said output from said first detector or of said output from said second detector, a first binary number source operable to provide a first binary number equal to the number of times that said first predetermined period is greater than said first fixed period, and a first numerical comparator, coupled to receive said first count from said first counter and to receive said first binary number, operable to provide a first output indicative of said first count being less than or equal to said first binary number, and operable to provide a second output indicative of said first count being greater than said first binary number, where said first output of said first numerical comparator is coupled as said first output of said timer unit and where said second output of said first numerical comparator is coupled to inhibit the further provision of said first clock pulses to said first counter.

Claim 18

Control equipment according to claim 16, wherein said second timer comprises: a second clock source operable to provide a second repetitious series of clock pulses of a second fixed period, a second counter, coupled to receive said second clock pulses, operable to increment a second count upon the receipt of each one of said second clock pulses, and operable to have said second count reset upon receipt by said timer unit of said output from said sensor, of said output from said first detector or of said output from said second detector, a second binary number source operable to provide a second binary number equal to the number of times that said second predetermined period is greater than said second fixed period, and a second numerical comparator, coupled to receive said second count from said second counter and to receive said second binary number, operable to provide a first output indicative of said count being less than, or equal to, said second binary number, and operable to provide a second output indicative of said second count being greater than said binary number, where said first output of said second numerical comparator is coupled as said second output of said timer unit and where said second output of said second numerical comparator is coupled to inhibit the further provision of said second clock pulses to said second counter.

Claim 19

Control equipment according to claim 17, wherein said main power source comprises an electrical supply main, wherein said first control comprises a first electrical switch, wherein said second control comprises a second electrical switch, and wherein said first relay switch comprises an electrically-operable relay for controlling the connection of said electrical supply main to said plant in concert with said first control.

Claim 20

Control equipment according to claim 18, wherein said first detector comprises a first auxiliary pair of contacts on said first switch, and wherein said second detector comprises a second pair of auxiliary contacts on said second switch.

Claim 21

Control equipment according to claim 19, wherein said second relay switch comprises an electrically-operable relay for controlling the connection to said second portion of said plant in concert with said first control and said first relay switch.

Claim 22

Control equipment according to claim 20, for use where said plant is a printing plant.

Claim 23

Control equipment according to claim 21, wherein said first portion of said plant comprises printing equipment, wherein said second portion of said plant comprises a paper take-up apparatus, and wherein said material for transfer between said first portion and said second portion of said plant is a moving paper web.

Claim 24

Control equipment according to claim 22, wherein said moving paper web comprises a plurality of regularly spaced holes longitudinally disposed therein, and wherein said sensor is an optical sensor for sensing said holes.