Patent GB-415931-A (GB)
Title: Improvements in elevator door mechanism
IPC: B66B13/12
Filed: 1933-12-14
Abstract: 415,931. Operating and locking lift doors. WAYGOOD-OTIS, Ltd., 54, Fetter Lane, London. Dec. 14, 1933, No. 35190. Convention date, Oct. 11. [Class 65 (i).] In mechanism for unlocking and operating a lift-shaft door by an operating member on the car, two members associated with the shaft door are provided for engagement by the operating member for the opening and closing movements respectively, and it is arranged that there is normally ample running clearance between both of these members and the operating member, but these clearances are partially or completely taken up when the opening movement of the door commences and are not restored until the door is closed ; there is thus little or no play in the mechanism during operation of the door and yet there is ample clearance for all parts when the lift is passing the landing. Means may be provided whereby the shaft door may be unlocked from the landing, such means either being operable only when the car is at the landing, for use of the staff in general service, or being independent of the position of the car, for emergency use ; service and emergency unlocking means may be provided together, operated by non-interchangeable keys. The unlocking of the shaft door operates an interlock switch to open the circuit controlling the movement of the car. The car door may be operated by power means, the mechanism being also adapted for manual operation, and an additional interlock switch may be operated by this mechanism. Fig. 5 is a view from the car, looking at the inside of the shaft door 67, which opens by sliding to the right ; all the mechanism shown is mounted on the shaft door or doorway with the exception of the plate 66, which constitutes the operating member and is mounted on the car for lateral movement to the right, the parts being shown in their normal positions. The two members which are engaged by the operating member 66 for operating the door are constituted by rollers 81, 82 mounted on bellcranks 71, 72 pivotally mounted at 73, 74 on the door 67, the pivot 74 passing through a clearance slot in the arm 92 of the crank 71 ; the pins on which the rollers 81, 82 are carried are formed with eccentric mounting pins held in split sockets in the ends of the cranks 71, 72, so that the positions of the rollers relative to the operating member 66 may be adjusted by rotating the roller mounting pins in their sockets, the pins being held in adjusted position by tightening the split sockets by screws. The cranks 71, 72 are connected by a pin 77 on crank 72 engaging a short horizontal slot in arm 92 of crank 71. The interlock switch comprises two pivoted contacts 98 engaging, in the position shown, with contact studs on a verticallysliding member 96 of insulating material carrying a pin 101 for engagement with the end of the arm 92 of crank 71 ; the lower end of the member 96 has a lug to be engaged by the underside of arm 92 to open the switch if it fails to open under its own weight or the force of an auxiliary spring which may be provided. The arm 92 is formed as a hook to engage a lip 95 on the casing of the interlock switch to lock the door in the closed position. A lever 105, pivoted on the switch casing, carries a roller engaging the underside of arm 92, and a spring 106 acting on the other end of the lever presses the arm 92 upwards to keep it in engagement with the lip 95 and to hold the switch closed ; this also keeps the rollers 81, 82 clear of the operating member 66. In operation, the first movement of member 66 to the right brings it against the roller 81, thus pressing the crank 71 to the right and carrying arm 92 clear of the lip 95 to unlock the door and at the same to open the interlock switch ; this movement of crank 71 causes, through the pin-and-slot connection 77, movement of crank 72 to bring roller 82 against the other side of the member 66, and a latch 87 pivoted on crank 71 then engages over the mounting pin of roller 82 to hold the two cranks together with their rollers in contact with the member 66. Further movement of member 66 opens the door 67, and there is no play in the mechanism in this movement or in the subsequent closing. As the door approaches the closed position, the nose of latch 87 engages a fixed pin 104, and the latch is thus released; the arm 92 of crank 71 engages the roller on the end of lever 105 and is pressed up to close the switch and engage the fastening lip 95, and this movement causes the crank 72 to carry its roller 82 well away from the member 66, a slight final movement of the latter member then bringing it clear of roller 81. In a modification, the lever 105 may be dispensed with, the spring 106 being transferred to act between the cranks 71, 72, or on either of them, to press crank 71 in a clockwise direction. For unlocking the door from the landing, a member movable against the pressure of a spring is provided inside the shaft, with provision for actuating it by a key or lever from outside ; in the case of emergency unlocking means, the movable member is arranged to press against the roller arm of crank 72 to unlock the door ; in the case of the service unlocking arrangement the movable member is placed clear of the cranks and is adapted to press against the operating member 66 if the car is present, thus moving this member to unlock the door, but if the car is not at the landing the actuation of the movable member of the unlocking means will have no effect. In a modification of the crank mechanism, the crank 72 is not used, and both rollers 81, 82 are mounted on the crank 71, one near the pivot and one at the lower end, the crank being bent to bring the rollers on opposite sides of the operating member 66 ; the latch 87 has its engaging notch facing the other way, and engages a pin fixed on the door. The operating member 66 is shown in Fig. 1 as being mounted on the car door 22, but it may be mounted in any other way on the car ; it may be formed of a channel or other member. The operating mechanism for the car door 22, Fig. 1, comprises an arm 37 connected to the door by a link 38 and fixed to a shaft 30 which has another arm 31 connected by chain 36 to a crank-pin on a wheel 27 driven through gearing by an electric motor; the wheel 27 carries lugs 48, 51 which operate limit switches 50, 52. The motor only performs the opening of the door, the closing being effected by a spring 40 connected by a chain 41 to an arm 34 fixed on the shaft 30 ; the speed of closing is controlled by the motor, which exerts a resisting pull on the chain 36 if the door-closing speed tends to be above that corresponding to the motor speed. A fluid check 42, connected to a fourth arm 32 on shaft 30, cushions the final closing. The arm 32 carries a pin 45, adjustable on the arm, which engages the chain 41, as the door approaches the open position, to increase the initial closing force exerted by the spring. The motor is preferably provided with a mechanical brake, which, in the form described, is released during operation by a cam on the shaft of the wheel 27 ; the brake is on at the beginning and end of the motion, but as these are dead-centre positions of the chain 36 the resistance is compensated by the absence of resistance from the door. An interlock switch 61 operated from the shaft 30 may be provided. The door is carried by rollers 160 running on a track 161 of J-section, the ends of the track being slightly bent up so that the track forms a trough for oil to reduce wear.