Abstract: A drive arrangement for a roller curtain covering an opening defined by a frame includes a drum mounted horizontally across one side of the opening, a pair of hollow drive shafts fixed against rotation in opposite ends of the drum, and a pair of coaxial tension shaft portions fixed to the frame and received through respective hollow drive shafts. At least one coil spring is associated with each tension shaft portion, each spring having a first end fixed to a tension shaft portion and a second end fixed to the drum. A pair of drive motors are operatively connected to respective hollow drive shafts for synchronously rotating the drive shafts in order to coil a roller curtain on the drum.

Abstract: A drum driving device for a window shade includes a housing fixed to a frame of the window shade. A cord pulley is rotatably received in the housing. A drum is rotatably mounted to a drum shaft received in the housing A single-direction clutch device is mounted between the drum and the cord pulley. The clutch device includes a chamber defined in the housing. A driving shaft is coaxially mounted to the cord pulley. A transmission shaft is mounted in the chamber. A driving spring is mounted to an inner periphery of the chamber and around the driving shaft and the transmission shaft in the chamber. The transmission shaft has an outer diameter not larger than that of the transmission shaft. The driving spring is in tight contact with the driving shaft and the inner periphery of the chamber. The transmission shaft is extended out of the chamber and connected to the drum.

Abstract: A drive arrangement for a roller curtain covering an opening defined by a frame includes a drum mounted horizontally across one side of the opening, a pair of hollow drive shafts fixed against rotation in opposite ends of the drum, and a pair of coaxial tension shaft portions fixed to the frame and received through respective hollow drive shafts. At least one coil spring is associated with each tension shaft portion, each spring having a first end fixed to a tension shaft portion and a second end fixed to the drum. A pair of drive motors are operatively connected to respective hollow drive shafts for synchronously rotating the drive shafts in order to coil a roller curtain on the drum.

Abstract: An assembly for covering an opening comprises a movable cover having a first flexible cover part that can be wound on or off a winding tube, a second rigid cover part attached to the first cover part at the end of latter remote from the winding tube and a third flexible cover part attached to the second cover part at the end of latter remote from the first cover part, wherein the free end of the third cover part extends around a reversing member which is movable by a first driving member, which free end is connected to a second driving member, and wherein the ratio between the winding velocity V1 of the winding tube, and thus the first and second cover parts, the driving velocity V2 of the first driving member and the driving velocity V3 of the second driving member is such, that V1+V3=2 V2, whereas V3>V2>V1>0.

Abstract: A motor drive for a rolling steel door which includes a motor and a speed reducer driven by the motor to take up/let off the rolling steel door. A brake disk is rotated with the motor shaft of the motor, a sprocket wheel is moved along an axle and forced by a spring into engagement with the brake disk to stop the motor shaft of the motor from rotation. An electromagnet is securely mounted on the axle and magnetized to attract the sprocket wheel for enabling the motor shaft of the motor to rotate freely upon starting of the motor. A lever operated by hand disengages the sprocket wheel from the brake disk. A control box is coupled to the power output shaft of the speed reducer to control the operation of the motor, wherein when the control box is controlled to start the motor, the electromagnet is magnetized to attract the sprocket wheel from the brake disk and enables the motor shaft of the motor to be freely rotated.

Abstract: An electromechanical sun visor for a motor vehicle window includes a sun shade screen rolled onto a spring-loaded takeup roller and a roller housing attachable to the interior of the roof of the vehicle adjacent the window upper side. A rotatable shaft is driven in forward and backward directions with a bidirectional electric motor connected to the car battery to retract and extend the sun shade screen. Extreme positions of the screen are detected with microswitches that control shut off of the motor.

Abstract: A door operator having a fluid drive motor and a manual override. The bidirectional hydraulic motor connects to a drive shaft through a power train including a shiftable --quill--type manual clutch mechanism which allows an alternate connection of the drive shaft to a manually-operated wheel. When the cable which shifts the clutch for manual drive is pulled, a switch disables the control for the hydraulic motor. When the motor is not provided with pressured fluid from the pump a hydraulic brake engages the motor.

Abstract: A clutch or rolling door operating mechanism permits use of two sources of power for moving the door between open and closed positions. A drive gear rotates about an eccentrically mounted shaft which itself is turned through a clutch of the fixed drag type to swing the gear into engagement with the drive train for moving the door via manual power and to permit the gear to swing into disengagment with such drive train for moving the door by electric power operation. In one form a circuit interlock prevents motor operation during manual driving of the door; in a second form an audible "clacker" sounds to indicate manual operation of the operating mechanism.

Abstract: The fireplace screen comprises a frame defining a central opening and including first and second pairs of vertical guide tracks along opposite lateral sides of the opening. A housing is mounted above the frame and a first flexible covering element is mounted for movement in the first pair of guide tracks. The first flexible covering element comprises a perforate mesh formed of heat resistant material. A second flexible covering element is mounted for movement in the second pair of guide tracks. The second covering element comprises an imperforate heat resistant material. A mechanism is mounted in the housing for individually raising and lowering the first and second covering elements in the guide tracks thereby covering and uncovering the central opening.