DEVICE FOR INDICATING APPEARANCE OF MAN IN CRANE WORKING ZONE Russian patent published in 2005 - IPC

FIELD: materials handling facilities; safety engineering.

SUBSTANCE: proposed device contains sensitive element interacting with control elements and installed in lower part of object housing, and warning unit placed in control circuit. Voltage source 1 is electrically connected with input of reversible travel motion starter 2 with normally closed contacts 3 whose output is connected at one side with time delay relay 4 with its power contacts 5 and through normally closed contact of cutoff relay 6, with step-down transformer 7 whose output is connected with series-connected sensitive element 8, signaling relay 9 with normally-open power contacts 10, red warning lamp 11 and howler 12, and at other side, with travel motion control contactor 13 and travel motion motor 14. Time relay 4 is connected through green lamp 15, and load grip switch 16 with series-connected load grip control contactor 17, reversible load grip control starter 18 and load grip motor 19. Sensitive element is made in form of infra-red radiation pickup.

EFFECT: simplified design.

2 cl, 1 dwg