Safety interlock for twin guard injection moulding machines - using mechanically linked guards and one set of relays

摘要

Injection moulding machines having a sliding gate on each side of the machine to prevent access to the daylight as the platens close, where one gate is fitted with a linear cam track which actuates levers and relays to interrupt platen movement unless the guard is closed, and the second gate is mechanically linked to the first and thus protected by the same set of relays. It is esp. applicable to large machines which are usually provided with two independent vertical gates instead of a tunnel gate bridging the whole machine. The switching logic is less complicated than systems involving response of one platen closing system to independent sets of guard relays associated with each of two safety gates.