Patent GB-384046-A (GB)
Title: Improvements in folding doors
IPC: B60J5/06
Filed: 1931-10-27
Abstract: 384,046. Doors for passenger vehicles ; floors. ENGLISH ELECTRIC CO., Ltd. 28, Kingsway, London, and WARNER, P. E., Mayfield, Chapel Lane, New Longton, near Preston. Oct. 27, 1931, No. 29755. [Classes 103 (ii) and 103 (iv).] Folding doors, particularly for tramcars and other vehicles comprising a leaf hinged to the door frame and a second leaf hinged to the free edge of the first, are operated by means rotating the first leaf about its hinge axis and guide means are provided to impart to the second leaf, on rotation of the first, a folding motion about the hinges between the leaves and to constrain the free edge of the second leaf to a path between its extreme positions ; the guide means comprise a member mounted on the outer end of the second leaf, a member on a bracket secured to the second leaf and extending back past the hinges between the leaves, and fixed guides adapted to engage with these members. When the doors are mounted on the step of a vehicle, a guard-plate is provided to cover the opening in the floor inside the vehicle when the doors are closed, and this guard-plate is brought into and out of position by the doors themselves. The arrangement shown comprises double folding doors for a tramcar having tapered ends. Each door comprises a leaf a mounted on a vertical shaft d and a leaf b hinged to the free edge of leaf a at c. The leaf b carries at the top a roller g near the free edge and a bracket e at the hinged edge extending back past the hinged edge. The roller g engages a channel guide A<1> on the door frame when the door is near the closed position, and a roller f on the bracket e engages a guide A when the door is near its open position, the guides being so arranged that the door is always positively guided by one or the other ; the guide A causes unfolding of the doors at the commencement of the closing movement, so that the doors may be folded quite flat and no excessive force is required ; the free edge of leaf b moves approximately parallel to the plane of the doorway opening. The shafts d carrying the doors have sprockets at the top, and these are connected by crossed rods, with short lengths of chain passing round the sprockets, so that both doors open together; the sprockets are of different sizes to allow both doors to open to a position perpendicular to the length of the vehicle. The shaft d of one door on each side carries an additional sprocket connected by chain and rod gearing, including a turnbuckle for adjustment, to a central control gear at the driver's position. This control gear, Fig. 6, comprises a handle k<1> operating a shaft carrying a sprocket m<1> connected to the doors on one side of the vehicle and a handle k<2> fixed to a sleeve on the shaft, the sleeve carrying a sprocket m<2> for the other set of doors. Between the two handles is a disc w having notches in which catches on the handles engage to hold the doors open or closed. The doors are situated on the step of the vehicle, and in order to cover the opening in the floor, which allows opening of the doors, when the doors are closed a plate n, Fig. 1, is provided, sliding on rollers under the floor in a direction perpendicular to the length of the vehicle. A lever L is pivoted at its centre to this plate and has slotted ends engaging pins on brackets B at the bottom of the leaves a of the doors, so that the movement of the doors is transmitted to the plate n without any twisting effect due to the difference in movement of the two doors.