Redundant sprocket logic system for machine tool numerical control

Claim 2

In a numerical machine tool control system comprising a tape reader for reading input instructions in the form of coded information bits disposed in successive rows on a flexible tape, each row being provided with a sprocket synchronization bit and at least one information bit in one of a plurality of parallel channels, a redundant sprocket logic system comprising means generating a tape sprocket signal from each successive sprocket bit, means generating a general channel signal from each successive row as long as said row includes at least one information bit, and means generating a logic sprocket signal from the occurrence of said general channel signal for controlling the operation of said machine control system even in the absence of said sprocket bit being read from said tape by said tape reader, wherein the means generating a general channel signal is a flip-flop set by the leading edge of the first of said information bits read by said tape reader and reset after a predetermined delay.

Claim 3

The system of claim 1 further comprising means actuating a sprocket fault alarm in the absence of either said tape sprocket signal or said logic sprocket signal.

Claim 4

The system of claim 1 further comprising means acTuating an input fault alarm in the absence of both said tape sprocket signal and said logic sprocket signal.

Claim 5

The system of claim 3 wherein said means actuating an input fault alarm further disables the machine tool control system.

Claim 6

The system of claim 1 wherein the means generating a tape sprocket signal is a flip-flop set by the trailing edge of the sprocket bit read by said tape reader and reset after a predetermined delay.

Claim 7

The system of claim 1 wherein the means generating a logic sprocket signal is a flip-flop set by the trailing edge of the general channel signal and reset after a predetermined delay.

Claim 8

In a numerical machine tool control system comprising a tape reader for reading input instructions in the form of coded information bits disposed in successive rows in parallel channels on a flexible tape adapted for translation relatively to said tape reader, each row of bits including a sprocket bit and at least one information bit in one of said channels, a redundant sprocket logic system comprising: means associated with the tape reader for generating a pulse signal for each sprocket bit and a separate pulse signal for each of the information bits in a row, means generating a tape sprocket signal from said first pulse signal, a flip-flop generating a logic sprocket signal from any one of said second pulse signals by setting said flip-flop by way of the leading edge of the first of said second pulse signals to occur, said flip-flop being reset after a predetermined delay, and means operating said control system in timed relationship with the occurrence of either said tape sprocket or said logic sprocket signal.

Claim 9

In a numerical machine tool control system comprising a tape reader for reading input instructions in the form of coded information bits disposed in successive rows in parallel channels on a flexible tape adapted for translation relatively to said tape reader, each row of bits including a sprocket bit and at least one information bit in one of said channels, a redundant sprocket logic system comprising: means associated with the tape reader for generating a pulse signal for each sprocket bit and a separate pulse signal for each of the information bits in a row, means generating a tape sprocket signal from said first pulse signal, a flip-flop generating a logic sprocket signal from any one of said second pulse signals by setting said flip-flop by way of the leading edge of the first of said second pulse signals to occur, said flip-flop being reset after a predetermined delay, and means operating said control system in timed relationship with the occurrence of either said tape sprocket or said logic sprocket signal.

Claim 10

The system of claim 7 further comprising means turning an alarm when either said tape sprocket signal or said logic sprocket signal is missing.

Claim 11

The system of claim 7 further disabling said control system when both said tape sprocket signal and said logic sprocket signal are missing.

Claim 12

The system of claim 7 further disabling said control system when both said tape sprocket signal and said logic sprocket signal are missing.

Claim 13

In a numerical tool control system comprising a tape reader for reading input instructions in the form of coded information bits disposed in successive rows in parallel channels on a flexible tape adapted to be translated relatively to said tape reader, each row of bits including a sprocket bit and at least one information bit in one of said channels, a redundant sprocket logic system comprising: first means associated with the tape reader for generating a first pulse signal for each sprocket bit, second means associated with the tape reader for simultaneously generating a second pulse signal for each information bit in a channel in a row, a tape sprocket flip-flop set by the trailing edge of said first pulse signal and reset after a predetermined time delayed by a reset signal, a general channel flip-flop set by the leading edge of the first of said second pulse signals to occur and reset after a predetermined time delay by said reset signal, a logic sprocket flip-flop set when said general channel flip-flop is set and reset by said reset signal, a sprocket flip-flop set when either said tape sprocket flip-flop or said logic sprocket flip-flop is set and reset by said reset signal, said sprocket flip-flop having an output controlling the timed operation of said machine tool control in a normal manner when set, and a sprocket fault flip-flop normally reset and remaining reset as long as both said tape sprocket flip-flop and logic sprocket flip-flop are set and said sprocket fault flip-flop being set by said reset signal when either said tape sprocket flip-flop or logic sprocket flip-flop is reset.

Claim 14

In a numerical tool control system comprising a tape reader for reading input instructions in the form of coded information bits disposed in successive rows in parallel channels on a flexible tape adapted to be translated relatively to said tape reader, each row of bits including a sprocket bit and at least one information bit in one of said channels, a redundant sprocket logic system comprising: first means associated with the tape reader for generating a first pulse signal for each sprocket bit, second means associated with the tape reader for simultaneously generating a second pulse signal for each information bit in a channel in a row, a tape sprocket flip-flop set by the trailing edge of said first pulse signal and reset after a predetermined time delayed by a reset signal, a general channel flip-flop set by the leading edge of the first of said second pulse signals to occur and reset after a predetermined time delay by said reset signal, a logic sprocket flip-flop set when said general channel flip-flop is set and reset by said reset signal, a sprocket flip-flop set when either said tape sprocket flip-flop or said logic sprocket flip-flop is set and reset by said reset signal, said sprocket flip-flop having an output controlling the timed operation of said machine tool control in a normal manner when set, and a sprocket fault flip-flop normally reset and remaining reset as long as both said tape sprocket flip-flop and logic sprocket flip-flop are set and said sprocket fault flip-flop being set by said reset signal when either said tape sprocket flip-flop or logic sprocket flip-flop is reset.

Claim 15

The system of claim 11 wherein said sprocket fault flip-flop turns an alarm on when set.

Claim 16

The system of claim 12 wherein said sprocket fault flip-flop is reset at the end of a block of input instructions.

Claim 17

The system of claim 11 further comprising an input fault flip-flop normallY reset and remaining reset as long as either or both of said tape sprocket flip-flop and said logic sprocket flip-flop are set, said output fault flip-flop being set by said reset signal when both said tape sprocket flip-flop and said logic sprocket flip-flop are in a reset condition.

Claim 18

The system of claim 14 wherein said input fault flip-flop turns an alarm on when set.

Claim 19

The system of claim 15 wherein said input fault flip-flop disables said control system when set.

Claim 20

The system of claim 16 further comprising manual reset for said input fault flip-flop.