170,078. Dorneth, J. July 8, 1920. Night-latches and like spring locks; locks, revolving-barrel; controlling operation of; preventing picking; multiple fastenings; door chains and the like.-A doorlocking device has a sliding bolt locked by a bell-crank lever carrying a floating pin which is operated by a revolving-barrel lock. A flat plate 2, covered by a casing 26, is attached to the door 1, and two pins 3, 4 project from it and carry adjustable blocks 5, 6, which are connected by a plate 7. The bolt 8 slides in bores in blocks 5 and 6 and has adjustably mounted on it a block 9 with a projection 11 having an horizontal slot in which works a pin 10. This pin is secured to one arm 12 of a bell-crank lever 12, 13 pivoted on a pin 14 on the projection 11. When the key 53, Fig. 9, is inserted in the barrel 17 of the lock, it positions the suspended tumblers 57 so that they can revolve, their slots 54 passing over the edge 52 of the pivoted member 63. The lever 16 of the barrel, Figs. 1 and 3, then comes into contact with the pin 10 and moves it, rocking the bell-crank lever 12, 13, and freeing its end 18 from engagement with the block 6. The pin 10 is then at the end of the slot in the projection 11, and further rotation of the key pushes the projection to the right, withdrawing the bolt. A gravity lever 21 falls over the end of the bolt when the door is opened and prevents its being shot by the spring 20. On closing the door, the striking-plate 19 pushes aside the lever 21 and allows the bolt to protrude. A spring pin 27 can be pushed into a slot 28 in the arm 13 of the bell-crank lever to prevent release of the bolt until the pin is withdrawn. If the lever 12, 13 is turned by the key sufficiently to disengage its shoulder 18 from the block 6. and the pin 27 inserted to engage with its upper face, to prevent its return, the bolt can be withdrawn, from the inside, by pulling its milled end, and from the outside, by the key. Pivoted to the bracket 23 of the striking-plate is a slotted arm 24, which, when lifted up, allows the door to be opened a few inches without withdrawing the bolt, the head of which slides down the slot in the arm. In the modification shown in Fig. 5, two bolts 8 are rigidly connected by. a bar 33 having pins 32. A sliding bar 31 has bent-up edges 35 which, in the locked position, engage behind the pins 32, preventing the withdrawal of the bolts. These are released by turning the bellcrank lever 36 by a handle, when the upper arm lifts the bar 31 by means of a pin 37, while the lower arm pushes back the bar 33, withdrawing the bolts. The same operation may be performed by means of the revolving-barrel lock 17 working a bell-crank lever 42, 43. A stop pin 27 may be provided on the inside to engage a projection 44 of the sliding bar 31. The lock may be attached to an alarm as shown in Figs. 7 and 9. Pressure of the tumblers 51 against the edge 52 of the member 63 pivoted at 56, or rotation of the barrel in the wrong direction bringing the lever 16 to the shoulder 55, rocks the member 63 and rings the alarm bell 60. A slot 62 prevents the separate arrangement and partial rotation of the tumblers to release the lock.