GB428219A - Improvements in safety devices for locking the landing gates and control means of mechanically operated lifts - Google Patents

Abstract

428,219. Lift doors interlocking with operating-gear. JONES, C. E., Victory Works, Bradford, Yorkshire. Nov. 7, 1933, No. 30883. [Class 78 (iii)] Combined mechanical and electrical interlocking devices are used to prevent either the well or cage door of a lift from being opened unless the cage is opposite the landing with the hand-controlled starting-gear in the " off " position ; the opening of a door then automatically locking the starting-gear, which remains locked until all doors are re-closed; the operation of re-starting the lift then automatically re-locking the cage and well doors. The arrangement is such that while all doors are doubly interlocked so long as the cage is not stationary at a landing, the electrical interlock of all of them is released whenever the cage is stationary at any landing, but the mechanical interlock of the doors at that landing only is freed. Fig. 1 shows diagrammatically the application of the apparatus to a lift with two landings only, the endless control rope R being operated to manipulate belt-shifting forks for transferring driving-belts between fast and loose pulleys. Each door or gate carries a locking-bar g<1> adapted when the gate is closed to hook over the main locking latch C and swing the latter clockwise to close the switch E. This completes a circuit through the solenoid s<1> and causes the bolt S to be withdrawn from the member K to release the hand-rope. As soon as the hand-rope is operated from the " off " position, the cam M releases the switch arm T which automatically changes over from contact t<1> to contact t<2>. This establishes a circuit through the gate solenoids F and locks all the main latches C electrically. As the cage leaves the landing, the roller h<2> rides off a projection a<1> in the cage and the mechanical interlock then is effected. Fig. 3 shows the actual construction of the mechanism for operating the bolt S and switch arm T. The solenoid is enclosed in a casing s<3> carrying a superposed casing s<4>, in which an economy coil is fitted, the whole being mounted on a bracket W. A projecting bracket w<1> on the casing forms a guide for the bolt S and also carries a pivot for the switch-operating arm T which is linked to the arm t<6> of the actual switch. The cam M is circular, except for the recess m<1> which is in alignment with the boltreceiving recess k<1>, and also carries an outer guide member m<2> which guides and forces the shorter arm of the lever T down into the recess when the two are in register. A spring may assist this movement. Figs. 7 and 11 show the construction of the main locking latches and the mechanical interlocking gear. The locking-bar g<1>, Fig. 11, on the closing door, contacts with the projection c<7> on the main locking latch C and swings the latter about the pivot c<5> so that (1) the member e<3> is raised to close the switch in the box E ; (2) the hooked portion c<4> is brought into register with the hooked end of the bar to prevent reopening of the gate ; and (3) the bar f<1> pivoted on the same shaft is pushed into the radius of action of the electromagnet F when the latter is energized. A tail-piece f<2> of the bar f<1> engages the latch C and prevents rotation of the latter when the magnet is energized. The bar h<3> of the mechanical interlock, which enters the casing at right angles to the path of the bar g<1>, fills up the space between the projection c<7> and the casing wall, thus also preventing rotation of the latch C. Fig. 7 shows a pivoted lever H, carrying the bar h<3> at its lower end and fitted with a roller h<2> which is provided in the well at each landing and is tripped by projections on the cage to hold the bar h<3> out of action while the cage is at a landing. When the locking-latches C are applied to doors on the cage, the rollers h<2> are provided on the cage and the operating cams at each landing in the well. In addition, the electrical connections are established through lag conductors in the well on which members projecting from the cage are guided, so that contact can be established in any position.