GB386406A - Safety interlock device for controlling the admission of fluid to a container - Google Patents

Abstract

386,406. Cleaning bedpans. HELLYER, R. H., 35, Red Lion Square, London. Dec. 4, 1931, No. 33652. [Class 26.] Relates to a safety interlock device between the door 3, Figs. 2 and 3, of a chamber, such as the chamber for cleaning bedpans described in Specification 344,593, and a valve 11 admitting steam or hot water thereto, said interlock device ensuring that the door shall not be opened until the valve is closed, and preventing the opening of the valve until the door is shut. Fig. 3 shows the arrangement in which the door 3 is closed and the valve 11 has been opened by the rotary screwed spindle 12, 13, 15, operated by the handle 16. In this opening action a worm 20 has engaged behind a lug 21 on the door 3 which is thereby locked in the closed position. To open the door 3, the valve spindle is first rotated to close the valve 11, in which position the handle 16 abuts against a stop 25 and the worm 20 clears the lug 21 and releases the door. When the door is opened a cylindrical locking bolt 22 slides forward under spring action 24 and passes into a gap 20a in the worm and thereby locks the valve spindle in this closed position. In the act of closing the door again, the lug 21 abuts on the reduced outer end 28 of the locking bolt, which clears the periphery of the worm, pushing the bolt forwards so as to release the worm as the door closes, whereupon the spindle 15 is rotated to engage the worm behind the lug 21, lock the door 3 and open the valve 11. In Fig. 2 the hopper 1 with its drain trap 2 is shown, a treadle 10 being provided for withdrawing a bolt 5 and allowing the door to open by gravity, under dashpot control 9, when released by the interlock means described above.