MACHINE PROTECTIVE DEVICE Russian patent published in 2014 - IPC H02H3/00 H02H3/20 H02H7/00 

FIELD: electricity.

SUBSTANCE: device includes a (+24 V) power supply circuit 1, directly connected to the output of the numerically controlled supply circuit of the machine, two parallel-connected safety relays, two protective diodes, three normally open contact switches and one normally closed contact switch, a resistor, the device is provided with at least two normally closed mushroom-shaped emergency switches, a feedback relay with a parallel-connected protective diode and a normally open contact, which can be connected to the numerically controlled system of the machine. The normally open contact is connected in series to the first safety relay; the supply circuit of the safety relay passes through a unit of normally closed emergency stop position switches, each at least made in form of one switch, connected in parallel by a jumper, having a normally open non-fixed contact with a key; the output of said contact switch of the first safety relay is connected in parallel to the coil of the second safety relay and the resistor of the device ON lamp. The safety relay is equipped with parallel-connected protective diodes, from the input of the supply circuit in parallel to the unit of normally closed emergency stop switches; the supply circuit is connected to the input of the numerically controlled system, connected in parallel to series-connected normally open contacts of the first and second safety relays, the output of which is connected to the output of the device for connecting to the numerically controlled system, and outputs of the safety relays and the feedback relay, protective diodes and ON lamp are connected to the "0" phase bus.

EFFECT: high reliability and safety of operation of the system, as well as operating speed thereof.

1 dwg