Abstract: A reinforcing bar for stiffening and guiding a flexible curtain in a vertically raisable door is fixed horizontally to the curtain and each of its ends penetrates into a corresponding vertical guiding slideway (1). At each of its ends, the bar includes a zone of reduced mechanical strength to enable the bar to escape from the guideways (1) when it is subjected to a thrust of given force substantially perpendicularly to the curtain (2). The bar is constituted, for example, by tubular portion (3) having two protective end pieces (43) fitted to its respective ends, with the end pieces being designed to break at zones of weakness (433).

Abstract: A support and transmission module (25) for the winding shaft (23) of a lifting curtain door, said shaft being rotated by an electric motor, comprises a closed case (30) containing at least two parallel module shafts (31, 33, 35). A primary module shaft (31) and a secondary module shaft (33) are colinearly connectable to the outlet shaft (32) of the motor and to the winding shaft (23), respectively. These module shafts carry toothed wheels (42, 43, 44, 45) which cause them to rotate together. They transmit torque generated by the motor (27) to the winding shaft (23) and they reduce the speed of rotation of said motor. Such a module is reliable and can be prefabricated industrially and fitted to any type of lifting curtain door, and makes it possible, in combination with another, similar module, to replace the score of parts normally required for providing a system for supporting and driving the winding shaft of a lifting curtain door.

Abstract: A vertically-opening door installation which is exposed to cold on one side includes a vertically-opening flexible curtain (6) and two risers to guide the respective side edge of the curtain. Each riser includes a lining (12) made of a material which is a poor conductor of heat and which lines the inside of the channel section bar, and at least one longitudinally-extending cavity (14) providing a cushion of air between the outside surface of the channel section bar and the inside surface of its lining. The inside surface of lining (12) is smooth. At least one of the longitudinally-extending cavities (14) may include electrical heater resistance (15) or similar heating devices. The riser is provided to prevent frost and ice from forming around the side edges of the curtain of a goods-handling door which is exposed to the cold.

Abstract: A counterweight (12) provided at the end of a shaft (8) for winding up the door-raising belts (3) of a concertina type door. The counterweight (12) is designed to open the door to a fraction of its height. It co-operates with the motor (7) when the door is being opened and closed under normal circumstances. A motor and brake unit (14) is provided including both the motor (7) and a brake for locking the shaft (8) when the motor is not in operation. Catch means may also be provided on the bottom of the door. Manual means are provided for releasing the shaft-locking brake means in the event of a power failure. The device is essentially a safety device and in the event of a motor breakdown or a power failure it enables the concertina-type door to be rapidly opened, at least partially. Similarly, in the event of the coupling between the drive shaft and the motor being broken, the device prevents the door from falling to its closed position in a catastrophic manner.

Abstract: The drive mechanism for a concertina-type door, including a motor and stepdown gearbox (1), a shaft (2) for winding up door-lifting belts (15), and an end-of-stroke unit (4), are mounted in a U-shaped metal channel section beam whose open side does not face downwardly and whose web is thus either the bottom horizontal portion of the beam, or else is disposed vertically. The beam (11) is fixed as a lintel at or near the top of door risers (12, 13), and is closed by a removable cover. The inside of the beam is lined with insulating material (16) and is equipped with a thermostatically controlled heater resistance. The beam housing enables the drive components to be maintained and repaired if need be without being removed from the door. It also enables a concertina-type door to operate safely in all weathers, and facilitates manufacture thereof.