Electronic thread guard

Claim 2

An electronic thread guard comprising a plurality of resistors each connected to a first supply lead, a corresponding plurality of glow discharge lamps connected to corresponding ones of said resistors, there being one series combination of resistor and glow discharge lamp for each thread or thread group to be guarded, a series resistor connected to said glow discharge lamps and a second supply lead, whereby each resistor, each glow discharge lamp and said series resistor in the above order are connected in series between the two supply leads which with respect to one another carry a stabilized voltage which somewhat exceeds the ignition voltage of the glow discharge lamps, the series resistor being common to all resistors and glow discharge lamps, a light-dependent resistor connected between the junction of each resistor and glow discharge lamp and a Supply point with a lower voltage than that junction respectively, said lightdependent resistor being illuminated as long as the thread or thread group concerned is tensioned and becoming obscured as soon as the thread or thread group concerned becomes slackened whereby in response to the occurrence of a break in one of the threads or thread groups the corresponding glow discharge lamp is ignited and ignition of the other lamps is prevented.

Claim 3

Electronic thread guard, according to claim 1, wherein the supply point with a lower voltage than the junction for each light-dependent resistor comprises a separate second glow discharge lamp of which one terminal is connected to said first supply lead to which the resistors are connected and the other terminal is connected through a second resistor to said second supply lead.

Claim 4

Electronic thread guard according to claim 1 wherein the circuit includes a device which stops the machine as soon as the voltage across or the current through the series resistor exceeds a predetermined value by the ignition of one of the first glow discharge lamps.

Claim 5

Electronic thread guard according to claim 2 wherein the circuit includes a device which stops the machine as soon as the voltage across or the current through the series resistor exceeds a predetermined value by the ignition of one of the first glow discharge lamps.

Claim 6

An electronic thread guard for guarding a plurality of threads or groups of threads comprising a first set of glow discharge lamps, there being one lamp having a voltage-dropping means connected thereto for each thread group to be guarded, a series resistor, said first set of lamps and said series resistor being connected in series between first and second voltage supply leads which carry therebetween a stabilized voltage somewhat greater than the ignition voltage of each of said glow discharge lamps, a second set of glow discharge lamps, there being one lamp having a voltage-dropping means connected thereto for each thread or thread group to be guarded, a plurality of light-dependent resistors, there being one resistor for each thread or thread group to be guarded, each light-dependent resistor being illuminated as long as the corresponding thread or thread group is tensioned and becoming obscured as soon as the thread or thread group becomes slackened, each of said light-dependent resistors being connected to a corresponding one of said lamps and voltage-dropping means in said first set and to one of said lamps and voltage-dropping means in said second set whereby in response to the occurrence of a break in one of the thread or thread groups, the corresponding glow discharge lamp in the first set is ignited and ignition of the other lamps in that set is prevented and each lamp in said second set is ignited independently in response to slackening of the corresponding thread or thread group.

Claim 7

An electronic thread guard for guarding a plurality of threads or groups of threads comprising a first set of glow discharge lamps, there being one lamp having a voltage-dropping means connected thereto for each thread group to be guarded, a series resistor, said first set of lamps and said series resistor being connected in series between first and second voltage supply leads which carry therebetween a stabilized voltage somewhat greater than the ignition voltage of each of said glow discharge lamps, a second set of glow discharge lamps, there being one lamp having a voltage-dropping means connected thereto for each thread or thread group to be guarded, a plurality of light-dependent resistors, there being one resistor for each thread or thread group to be guarded, each light-dependent resistor being illuminated as long as the corresponding thread or thread group is tensioned and becoming obscured as soon as the thread or thread group becomes slackened, each of said light-dependent resistors being connected to a corresponding one of said lamps and voltage-dropping means in said first set and to one of said lamps and voltage-dropping means in said second set whereby in response to the occurrence of a break in one of the thread or thread groups, the corresponding glow discharge lamp in the first set is ignited and ignition of the other lamps in that set is prevented and each lamp in said second set is ignited independently in response to slackening of the corresponding thread or thread group.

Claim 8

An electronic thread guard according to claim 5 wherein the circuit includes a device which stops the machine as soon as the voltage across or the current through said series resistor exceeds a predetermined value by the ignition of one of said glow discharge lamps in said first set.