GB171455A - Improvements relating to locks for exit doors - Google Patents

Abstract

171,455. Adams, S. J., and Adams. R. H., (trading as Adams, R.). Aug. 10, 1920. Emergency-exit fastenings; locking sliding latches; locks, controlling operation of; latches, sliding.-In an emergency-exit fastening, the bolt is released by a press-bar, but can be either blocked in its fully-shot position against release by a key-mechanism or by a handle, or held in a half-shot, latching position by means of a handset pawl. In the form shown in Fig. 1, the bolt 1 carries on it a sliding plate, a shoulder 8 on which, when the plate is moved to the right by the pressure on the push-bar, by an arm thereon engaging the slot S in the plate, or by the keymechanism 23, 24, tilts up the arm 4 by engaging its shoulder 9, lifting the blocking-piece 2 out of the path of the bolt. Further movement of the sliding plate pushes the bolt 1 to the right, withdrawing it. The push-bar can withdraw the bolt fully, but the key-mechanism, by the engagement betwen the lug 25 of the plate 23 and the lug 26 on the sliding-plate, can only withdraw the bolt to its half-shot or latch position. If the pawl 28 is now turned by hand to engage the lug 27 on the plate 23, the lock is maintained in its latching position and the bolt cannot be fully shot by the key until the pawl is released. In the form shown in Fig. 4, the key-actuated bar 30 can lift the blocking-piece 2 from behind the bolt 1, which can be withdrawn bv the handle 32 and follower 31. The press-bar can move the sliding plate 7 and lift the piece 2 and withdraw the bolt the same as before. The hand-operated pawl 28 holds the bolt 1 in its half-shot or latching position as in the form shown in Fig. 1, but, in this case, actuation of the bar 30 by the key tilts the end of the pawl 28 and releases it from its engagement with the bolt-lug 29, allowing the bolt to shoot fully forward. If desired the known slambolt release mechanism 12, 13 can be incorporated as shown in Fig. 1.