PENDULUM SAFETY LOCK
Original Publication Date: 1980-Jun-30
Included in the Prior Art Database: 2004-Apr-02
Xerox Disclosure Journal
A safety lock comprising a pendulum stop device in which a single interlock is necessary to provide and to limit access to a covered space is disclosed. In the closed position, the safety lock comprises a closed pendulum housing 10 having movably mounted within it a pendulum 11, which axially rotates on shaft 12. In the closed position, a horizontal bar 13 slides through two openings 14 and 16 in the pendulum housing 10, one on each side and holds the pendulum out of access within the openings. Still in the closed position, within the pendulum housing is a locking tab 18 attached to a first cover, which is inserted into the pendulum housing 10 with the bar 13 centered within a hole 19 in the tab. When the bar 13 is withdrawn horizontally, the locking tab 18 is released permitting the first cover to be opened and the pendulum to swing vertically into the pendulum housing 10 blocking reinsertion of the horizontal bar into the housing opening. To move the bar horizontally, a second cover must be opened to which a conventional interlocking switch is fitted. Reinsertion of the bar while the first cover is open is not possible since the pendulum blocks the opening of the housing. If the first cover tab 18 is inserted in the pendulum housing, it will lift or push the pendulum from the opening permitting insertion of the horizontal bar through the pendulum housing and the first cover tab. Thus, the interlock switch on the second cover will not be closed until the first cover is closed.