Patent GB-385994-A (GB)
Title: Improvements in or relating to lift safety devices
IPC: B66B13/18
Filed: 1931-07-07
Abstract: 385,994. Operating and locking lift cages and doors. COATES, A. F., Codring- ton Grange, Broadway Road, Bristol. July 7, 1931, No. 19496. [Class 78 (iii).] A lift safety device comprises an interlocking gear between a lift door and a switch associated with the drive of the lift whereby the switch is locked against closing when the door is open so as to prevent the lift being driven, and when the door is closed, the switch in moving to its closed position acts to lock the door. When the cage is in motion, Fig. 1, the switch 10 is closed by a lever 11 which is pivoted at 12 on a switch-box 27 on the landing and is controlled by a member 13 interlocking with a lever 18 which is connected bv a bar 20 with a lever 21 engaging a groove 24 in the sliding well door 3. An electromagnet 26, mounted on the cage adjacent an armature 25 on the member 13, is connected by links 29, 32, 33, to a hand-lever 36 having a part 37 closing a switch 9. When the cage is opposite the desired landing, the lever 36 is rotated anticlockwise so as to open the switch 9 and deenergize a solenoid controlling the lift circuit. The magnet 26 is simultaneously moved towards the armature 25 and the contacts 38, 39 closed so as to complete the magnet circuit. On further rotation of the lever 36, the magnet is moved to the right, withdrawing the bar 13 so as to remove the surface 43 clear of the arm 44 of the lever 18 and open the switch 10. When the lever 36 reaches its extreme position, Fig. 4, the contacts 38, 39 are open and the current to the magnet cut off. The door 3 may now be moved to the left, thereby swinging the lever 18 to the position shown in which it positively locks the bar 13 against movement to the left. To restart the lift the door is closed and the lever 36 rotated in a clockwise direction, the parts returning to the position shown in Fig. 1, in which the switch 10 is closed and the lever 18 locked by the bar 13. The lever 36 may be operated by the opening and closing of the cage door. In a modification the parts mounted on the cage are mounted on the well and vice versa, the switch 10 then being interlocked with the cage door. In a further modification, Figs. 6 and 8, the switch 10, mounted in a switchbox 27 on the landing, is closed by an arm 50 on a lever 50, 51, actuated by a handle 48, the arm 51 of said lever engaging a member 52, pivotally connected at 56 to a lever 53 on the well door so as to lock the door. When the desired landing is reached, the handle 48 is rotated clockwise so as to break the switch 10 and disengage the arm 51 from the member 52. When the door is now opened, Fig. 8, this member engages the surface 60 of the arm 51 to lock the switch in the closed position. To restart the lift the door is closed and the handle 48 returned to its initial position, the arm 51 then re-engaging the member 52 as in Fig. 6. An arrangement is shown in Figs. 10 and 12, whereby the handle 48 is moved automatically by the opening or closing of the cage door, the movement of the door being inoperative to move the handle 48 unless the cage is at or near a landing. A stud 63 on the handle 48 extends into a channel 71 of a member 62 which is mounted by links 66, 67 on a bracket secured to the cage and is moved vertically through mechanism connected to a rod 69, pivoted thereto, by the movement of the cage door. When the cage is stopped opposite a landing and the cage door is opened the member 62 will move upwards and horizontally so that the stud 63 is moved to the right and actuates the handle 48 to open the switch 10. When the cage door is closed the member 62 moves first to the left and then back a small distance to the right so that the stud is left clear of the channel. The vertical movement of the member 62 may be effected by a manually-controlled member.