Monitoring system

Claim 2

In an apparatus for monitoring the function of the electrical control of seven-element number indications in which each number is formed of from two to seven illuminated beams; an improvement therein which comprises first means for each number including seven terminals connected to supply signals for illuminating the said beams for the respective number, one second means for each monitoring control of indications connected to a selected pair of the said terminals for each number and sensitive to the signals supplied to said terminals, third Means connected to said second means and responsive jointly thereto for short-time brief and successive turning-on of respective indications one and two and operable to supply signals indicating the condition of operation of said electrical control, whereby the upper and intermediate transverse beams of each number indication are checked prior to each use of the indications to determine whether said upper and intermediate transverse beams can be turned on or off.

Claim 3

An apparatus according to claim 1 in which said second means comprises gate means operable to develop a signal in response to signals on the said terminals to which the gate means is connected.

Claim 4

An apparatus according to claim 1 in which each said first means includes decoder means having on the output side the seven output terminals pertaining to the respective number and having on the input side four input terminals for receiving signals corresponding to four element number indications and which are converted in the decoder into signals corresponding to said seven-element number indications and supplied to said output terminals, said second means including first gate means connected to receive signals from said selected pair of input terminals and said output terminals of each said decoder, a plurality of second gate means each connected to receive signals from the first gate means, and third gate means each connected to receive signals from a plurality of said second gate means.

Claim 5

An apparatus according to claim 3 in which said first gate means includes a first ''''and'''' gate having inputs connected to the pair of said output terminals of each decoder to which signals are supplied for the numeral 1, a first inverted ''''or'''' gate having inputs connected to the input terminals of each decoder which are at 0 for the numeral 1, said second gate means for each decoder comprising a first further ''''and'''' gate having inputs connected to the outputs of the said first ''''and'''' and first inverted ''''or'''' gates and to the input terminal of the said decoder to which a signal is supplied for the numeral 1, said third gate means comprising a first multiple input ''''and'''' gate having the inputs connected to the outputs of said second gate means.

Claim 6

An apparatus according to claim 4 in which said first gate means for each decoder comprises a second inverted ''''or'''' gate having inputs connected to the inputs of the first ''''and'''' gate and a third inverted ''''or'''' gate having inputs connected to the input terminals of the respective decoder which are at 0 for the numeral 2, said second gate means for each decoder including a second further ''''and'''' gate having inputs connected to the outputs of said second ''''and'''' gate and said third inverted ''''or'''' gate and to that input terminals of the respective decoder which receives a signal for the numeral 2, said third gate means comprising a second multiple input ''''and'''' gate having inputs connected to the outputs of said second further ''''and'''' gate.

Claim 7

An apparatus according to claim 5 in which said third means includes first and second bistable flip flops each having a pair of input terminals and a pair of output terminals, one output of said first flip flop being connected to supply a signal for the numeral 1 to said electrical control and also connected to an input of said first multiple input ''''and'''' gate, one output terminal of said second flip flop being connected to supply a signal to said electrical control for the numeral 2 and also connected to an input of said second multiple input ''''and'''' gate, the output of said first multiple input ''''and'''' gate being connected to the input terminal of said second flip flop which when supplied with a signal will cause the supply of a signal to the said first output terminal thereof, selectively operable signal supply means connected to the input terminal of said first flip flop which whEn supplied with a signal will cause the supply of a signal to the said first output terminal thereof, said output of said second multiple input ''''and'''' gate being connected to the other input terminals of said flip flops, a signal operating inverted ''''and'''' gate having inputs connected to the other output terminals of said flip flops.

Claim 8

An apparatus according to claim 1 in which said monitoring is effected by selectively supplying a signal for the numeral 1 to said electrical control.

Claim 9

An apparatus according to claim 1 in which said selected pair of terminals are those which supply the upper and intermediate beams.