Abstract: Motorized window treatment systems are disclosed. A motorized window treatment system may include a covering material, a sensor circuit, and a control circuit. The sensor circuit may be configured to generate sensor signals indicative of a position of the covering material. The control circuit may be configured to determine a present sensor state of the sensor circuit, determine a predicted sensor state for the sensor circuit based at least in part on a power-down position recorded at a first time and a final position recorded at a second time, compare the predicted sensor state with the present sensor state, and determine a present position of the covering material based on the comparison of the predicted sensor state and the present sensor state. Methods of adjusting a position of a covering material of a motorized window treatment also are disclosed.

Abstract: A sidewall assembly for an aircraft and an aircraft are provided. In one example, the sidewall assembly includes a window. A sidewall portion has an inner-facing side and at least partially surrounds the window. The sidewall portion and the window have a curved contour. A transparent display panel is coupled to the sidewall portion and covers the inner-facing side of the sidewall portion including the window. The transparent display panel includes a display screen configured to display information to a passenger. The transparent display panel including the display screen have a curved contour that substantially matches the curved contour of the sidewall portion and the window. A display controller is in communication with the transparent display panel to communicate a video/audio signal providing the information to the display screen.

Abstract: A load control system for a building having a lighting load, a window, and a heating and cooling system comprises a lighting control device, a daylight control device, and a temperature control device operable to be controlled so as to decrease a total power consumption of the load control system in an energy-savings mode. The energy-savings mode can be manually overridden in response to actuation of the actuator of an input control device, such that the load control system enters a manual mode for manually adjusting the loads controlled by the lighting control device, the daylight control device, and the temperature control device. The load control system is operable to automatically return to the energy-savings mode at a time after the load control system entered the manual mode.

Abstract: The present invention provides a curvature-adjustable backboard assembly and a curved display device. The curvature-adjustable backboard assembly of the present invention includes a curvable backboard, a slider-crank mechanism, and a first low-speed position-limiting electric machine.

Abstract: A movable partition system includes a movable partition, a floating jamb attached to an end of the movable partition and located within a pocket configured to retain the movable partition when in a retracted position, at least two base plates attached to the floating jamb, and at least two jamb stops attached to opposing interior walls of the pocket. Each of the at least two jamb stops are configured to engage a respective base plate of the floating jamb, wherein the floating jamb, the at least two base plates, and the at least two jamb stops are configured such that disengaging the floating jamb from a secure position within the pocket when the movable partition is in an extended position requires disengaging one of the at least two jamb stops from the respective base plate on each side of the movable partition. Methods of providing a security barrier are disclosed.

Abstract: The invention provides a sanitization booth 10 has side walls 12 approximately twice as long as it's entrance and exit openings 14, 16 are wide to permit a person to step into the booth and pass therethrough while being sprayed or misted with a sanitization or disinfection liquid, from above 18, below 20, and the sides 22 by liquid sanitizer pumped through a reticulation pipe system 24 and through nozzles 26 along the extent thereof, thereby to sanitize the person, their clothing, as well as their footwear including the soles thereof. The booth 10 includes a hand sanitization point 28 at the entrance 14 to the booth 10 so that the person who has been sanitized by passing through the booth also sanitizes their hands which have been used to cover their eyes while in the booth. The invention also provides a sanitization system and a kit for assembly of a sanitization apparatus.

Abstract: The present invention provides a curvature-adjustable backboard assembly and a curved display device. The curvature-adjustable backboard assembly of the present invention includes a curvable backboard, a slider-crank mechanism, and a first low-speed position-limiting electric machine.

Abstract: A motorized window treatment for controlling the amount of daylight entering a space through a window includes a covering material, a drive shaft, and a motor coupled to the drive shaft for raising and lowering the covering material. The window treatment also includes a spring assist unit for assisting the motor by providing a torque that equals the torque provided by the weight on the cords that lift the covering material at a position midway between fully-open and fully-closed positions to minimize motor usage and conserve battery life. The window treatment may comprise a photosensor for measuring the amount of daylight outside the window and temperature sensors for measuring the temperatures inside and outside of the window. The position of the covering material may be automatically controlled in response to the photosensor and the temperature sensors, or in response to an infrared or radio-frequency remote control.

Abstract: The present disclosure is directed to a flood barrier designed for the dry-flood proofing of door and window openings in a building. The flood barrier includes a rigid frame, preferably formed of metal extrusions. To this frame are clamped a water-impervious barrier and a sacrificial bladder to protect the water-impervious barrier from impacts by wind- or water-borne, debris and impacts. A number of webbings may be provided on the side of the water-impervious barrier opposite the sacrificial bladder to further support the water barrier layer. Sealing gaskets are provided on the rigid frame where the frame contacts the building, or in case of a door opening, also the floor. The sacrificial bladder permits water to accumulate between the sacrificial bladder and the water-impervious layer thereby utilizing the non-compressible nature of the water to attenuate the impacting force.

Abstract: A motorized window treatment may provide a low-cost solution for controlling the amount of daylight entering a space through a window. The window treatment may include a covering material (e.g., a cellular shade fabric or a roller shade fabric), a drive assembly for raising and lowering the covering material, and a motor drive unit including a motor configured to drive the drive assembly to raise and lower the covering material. The motorized window treatment may comprise one or more battery packs configured to receive batteries for powering the motor drive unit. The batteries may be located out of view of a user of the motorized window treatment (e.g., in a headrail or in a battery compartment). The motorized window treatment may use various power-saving methods to lengthen the lifetime of the batteries, e.g., to reduce the motor speed to conserve additional battery power and extend the lifetime of the batteries.

Abstract: A driving assembly for window blinds includes a mounting plate, a winding roller and driving wheels that are engaged with one another, at least one first guiding roller, and at least one second guiding roller. An elastic element is elastically wound around the driving wheels, a pull rope has a starting end fixed to the winding roller and is divided into at least two sections, under a first status, the pull rope partially winds around the winding roller then winds around the second guiding roller and the first guiding roller in turns along outer edges of the second and the first guiding rollers; while under a second status, the pull rope disengages from the winding roller, the second guiding roller and the first guiding roller in turns. The driving assembly has simple structure and convenient assembly, and brings effortless and quick operation to pull or lift the window blind.

Abstract: A manually operated override release mechanism for use with a motorized window shade assembly having a shade fabric with a leading edge, the shade fabric being disposed behind a pane and movable between an opened position and a closed position upon operation of a motor. The override release mechanism has an actuator movable between a first position and a second position and biased in the first position. The actuator has a first side secured to one end of a cable, and a second side. The other end of the cable is connected to the motor.

Abstract: A retractable cellular shade is illustrated in various embodiments to consist of a support structure that could assume numerous forms including cellular material, flexible sheets of material, tapes or ribbons, or flexible monofilaments or similar cords of natural or synthetic fibers with the support structure supporting a plurality of vanes or slats in various configurations and orientations. The movement of the vanes or slats is totally dependent upon movement of the support structure. The fabric so formed can be incorporated into a covering for architectural openings with the covering including a headrail with means for gathering the fabric material within the headrail.

Abstract: Disclosed is a roman shade assembly (100, 200) that utilizes lift bands (108, 208) rather than lift cords. The shade (110, 210) can be formed of textured materials or woven woods. The shade assembly includes lift bands (108,208) that attach to a rotatable member(s) (115, 215) and can be extended or retracted within an architectural opening by rotating the member(s). The lift bands can be slidingly connected to the shade at multiple points along the vertical length of the shade. Accordingly, as the wide lift bands are extended or retracted, the attached shade is likewise extended or retracted to cover or uncover an architectural opening.

Abstract: A fire barrier for buildings includes a ceramic fiber based material such as ceramic paper. The ceramic prevents the burning of the building in case of a fire. The ceramic material may be mounted to the building on spools prior to use and rapidly deployed therefrom in the event of a fire near the building.

Abstract: A covering for an architectural opening is provided. The covering may include a head rail, an end rail, and a cellular panel operably connected between the head rail and the end rail. The cellular panel may include at least one cellular unit. Each cellular unit may include a primary cell having a first side and a second side. In one configuration, the first side has a single crease, and the second crease has three creases. A vane may be operably connected to the primary cell and extend around at least a portion of a side of the primary cell.

Abstract: An expandable and contractable shade assembly includes at least a first column of cell structures aligned vertically one above another and a second column of cell structures also aligned vertically one above the other. The second column of cell structures can be positioned offset and nested with the first cell structures such that each second cell structure may be positioned in between two adjacent of the first cell structures. One or more lift cords may be encased or contained within the first cell structures. The first cell structures not only have lift cords but also provide the product with added integrity.

Abstract: Movable partition systems include a drive mechanism including a motor positioned at least partially on a side of a track opposite a movable partition. Automatically movable partition systems include a movable partition movable along a track and a motor configured to move the movable partition, the motor positioned on a side of the track opposite the movable partition. Methods of installing a movable partition system include coupling a movable partition to a track, positioning a drive mechanism at least partially on a side of the track opposite the movable partition, and coupling an elongated drive member to the movable partition. Methods of moving a movable partition along a track include actuating a drive mechanism positioned at least substantially in a header recess. Drive modules for a movable partition system and other methods of installing a movable partition system including attaching a motor to a section of track are also disclosed.

Abstract: A motorized window treatment controls daylight entering a space through a window and includes a covering material, a drive shaft, lift cords received around the drive shaft and connected to the covering material, and a motor coupled to the drive shaft. It also includes a spring assist unit for the motor providing a torque that equals the torque provided by the weight on the lift cords at a position midway between fully-open and fully-closed positions, minimizing motor usage and conserving battery life. A photosensor for measuring the daylight outside the window and temperature sensors for measuring the temperatures inside and outside of the window may be provided. The position of the covering material is automatically controlled to save energy, or may also be controlled in response to an infrared or radio-frequency remote control.

Abstract: A Venetian shade and Roman shade assembly is presented having a header with a drive shaft assembly positioned in the header, the drive shaft having a plurality of lift and tilt spool assemblies. A motor controller assembly is removably positioned within the header and connected to the drive shaft assembly. The motor controller assembly includes a motor, a plurality of batteries and a motor controller that is wirelessly controllable by a remote. When the motor of the motor controller assembly is activated, the motor rotates the drive shaft assembly thereby raising or lowering the shade material as well as tilting the shade material.

Abstract: The swing door assembly disclosed herein is formed and assembled to keep fluids (liquids) in particular (rain) water out of a building such as a home or business. An interoperating accordion screen is also disclosed. Several examples will be provided demonstrating a door that swings inward, a door that swings outward, and an example of each with an accordion style screen provided in the door assembly. Such accordion-style screen assemblies have been known to cause significant problems in transfer of fluid away from the exterior surface of the door and building due in part to the alignment channels needed to keep the accordion screens in proper position when closed.

Abstract: An actuating system for a window shade comprises a transmission axle, a spring drive unit operable to urge the transmission axle to rotate in a first direction for raising a shading structure of the window shade, and a control module including an arrester assembled around the transmission axle, and an operating cord operatively connectable with the transmission axle. The arrester has a locking state in which the arrester acts against the spring drive unit to block a rotational displacement of the transmission axle in the first direction, and an unlocking state in which rotation of drive axle is allowed. The operating cord is operable to turn the arrester from the locking state to the unlocking state and to drive rotation of the transmission axle in a second direction opposite to the first direction for lowering the shading structure of the window shade.

Abstract: A battery-powered motorized window treatment for covering at least a portion of a window may be adjusted into a service position to allow for access to at least one battery that is powering the motorized window treatment. A headrail of the motorized window treatment may be adjusted to the service position to allow for easy replacement of the batteries without unmounting the headrail and without requiring tools. The motorized window treatment may comprise brackets having buttons that may be actuated to release the headrail from a locked position, such that the head rail may be rotated into the service position. The headrail easily rotates through a controlled movement into the service position, such that a user only needs one free hand available to move the motorized window treatment into the service position and change the batteries.

Abstract: A remote control system for use with a movable partition comprises a motor configured to drive movement of a movable partition of a movable partition system, a processor coupled with the motor to generate an actuation signal to control the motor, and a remote control switch coupled with the motor and configured to transmit a trigger signal to the processor in response to receiving an activation signal from a remote control key. The processor is configured to control the motor to drive the movable partition to a predetermined position along a track in response to the trigger signal. A method of driving a movable partition comprises receiving an activation signal from a remote control key, and driving the movable partition to an intermediate position along a track to provide access to user interface elements of the movable partition in response to receiving the activation signal.

Abstract: A window covering includes a headrail, a bottom rail, a shading member, two pulley assemblies, and a cord. The shading member is between the headrail and the bottom rail. The pulley assemblies are received in the headrail, each of which has a frame and a pulley. The frame has an opening, and the pulley is connected to the frame. The cord is a woven Y-shaped cord, having a control section and two lift sections. The cord runs over the pulleys of the pulley assemblies, the control section extends out of the headrail to be operated by a user, and the lift sections extend out of the frames via the openings respectively to connect to the bottom rail through the shading member.

Abstract: A window cover system includes an extendible window cover with a pair of lift cords. A lift cord pulley shaft is coupled to a pair of spaced apart lift cord pulleys. A spring drive unit has a beveled gear system with a first gear that is spring biased to resist rotation of first gear in one direction of rotation, and a second gear meshed with the first gear. The lift cord pulley shaft extends through the second gear and is configured to rotate therewith.

Abstract: A window covering includes a headrail, a bottom rail, a shading member, two pulley assemblies, a car, a control cord, and a transmission cord. The shading member is between the headrail and the bottom rail. The pulley assemblies and the car are received in the headrail, and the car is free for reciprocation. The control cord runs around one of the pulley assemblies and the car, and then going out of the headrail to be pulled or released by a user. The transmission cord has a main section and two branch sections, wherein the main section runs around the other one of the pulley assemblies and the car, and the branch sections go out of the headrail to be connected to the bottom rail.

Abstract: A motorized window shade includes a head rail, a bottom part suspended from the head rail, and a covering structure arranged between the head rail and the bottom part. An electric motor is arranged in the head rail and is operable to drive a vertical displacement of the bottom part. The window shade further includes a control interface electrically connected with the electric motor, and suspended outward from the head rail. The control interface is operable to control rotation of the electric motor for raising and lowering the bottom part. An elongated tube may further be disposed outside the head rail. The elongated tube has an upper end connected with the head rail, and the control interface is assembled adjacent to a lower end of the elongated tube.

Abstract: The present disclosure describes a method and system by which a biometric client with a unique device ID and one or more biometric probes may request a token/certificate that may be used as an authentication credential for one or more cloud-based applications. Using a mobile or stationary computing device, the biometric client may submit one or more biometric probes along with an associated device ID to a cloud biometric authentication system, wherein said cloud biometric authentication system may use the device ID to search biometric templates for matching. If the comparison results in a successful match, a token/certificate is generated and returned to the biometric client. Until expiration, the biometric client may use said token/certificate to access one or more cloud-based applications.

Abstract: A battery-powered motorized window treatment for covering at least a portion of a window may be adjusted into a service position to allow for access to at least one battery that is powering the motorized window treatment. A headrail of the motorized window treatment may be adjusted to the service position to allow for easy replacement of the batteries without unmounting the headrail and without requiring tools. The motorized window treatment may comprise brackets having buttons that may be actuated to release the headrail from a locked position, such that the head rail may be rotated into the service position. The headrail easily rotates through a controlled movement into the service position, such that a user only needs one free hand available to move the motorized window treatment into the service position and change the batteries.

Abstract: A covering for an architectural opening is provided. The covering may include an accumulator roller, a shade attached to the accumulator roller, and a shade actuation system. The shade may be wrappable about the roller. The shade may include two laterally-separable sheets interconnected by a plurality of vertically-spaced vanes. The shade actuation system may be selectively engageable with a confronting face of one of the two laterally-separable sheets. Engagement of the shade actuation system and the one of the two laterally-separable sheets may restrict movement of the one of the two laterally-separable sheets relative to the other of the two laterally-separable sheets.

Abstract: A curtain structure without drawstring may include a curtain unit, a string scrolling base and an upper cover. The string scrolling base has a shell disposed in the base of the curtain unit, center portion of the shell having a shaft, both sides of which having a positioning shaft, and a line slot formed on both side walls of the positioning shaft, wherein upper periphery of rotating base has driving teeth having at least one groove, restricting guiding groove and arc rail groove on top surface thereof, and a driving unit is disposed on the positioning shafts, the driving unit having a rod to secure the string collecting bodies, and conjugating teeth are linked with the driving teeth of the rotating base; and an upper cover having a restricting groove corresponding to the rotating base, and a ball restricted in the groove of the restricting groove and the rotating base.

Abstract: A batter's eye or backdrop apparatus and system, and to a free-standing deployable batter's eye apparatus and system, including a panel which may be raised, lowered and/or removed, as desired. The apparatus and system are easy to install and maintain, designed to tolerate design wind loads by changing orientation, shape and/or area presented to winds in response to the winds and/or wind pressures. The batter's eye apparatus is flexible and allows for movement in instantaneous wind modes, thereby reducing the complexity and cost of a support structure for the batter's eye and the batter's eye system. The batter's eye also includes a panel, screen or sheet that may be raised, and lowered closer to the ground to provide further protection against damage due to winds and/or weather.

Abstract: A covering for an architectural opening is provided. The covering may include a rotatable roller, a shade attached to the rotatable roller, and a shade actuation system. The shade may be wrappable about the roller. The shade may include two laterally-separable sheets interconnected by a plurality of vertically-spaced vanes. The shade actuation system may be selectively engageable with a confronting face of one of the two laterally-separable sheets. Engagement of the shade actuation system and the one of the two laterally-separable sheets may restrict movement of the one of the two laterally-separable sheets relative to the other of the two laterally-separable sheets.

Abstract: A cordless curtain assembly includes a curtain unit, a control unit, a fixed part, a movable part and an operation cord. The curtain is connected between the head box and a bottom bar. The user may pulls the bottom bar to operate the operation cord which is wrapped to the first and second pillars in the fixed part and the movable part. The movable part is moved and activates the spring to lift the curtain. When the user lifts the bottom bar, the spring force is release so that the movable part moves back to its initial position to let the operation cord to pull the curtain upward.

Abstract: The invention relates to a winding apparatus for covering an opening. According to the invention transmitting means are provided for interaction between a drive unit and a winding element, having a windable pulling element which is received between a first rotatable winding body and a second rotatable winding body in such a manner that the pulling element can be wound and unwound by way of the first winding body which is driveable by the drive unit, wherein the second winding body and the winding element are rotatably coupled together and wherein the cover element can be wound by way of an unwinding operation of the pulling element from the second winding body.

Abstract: Movable partition systems include a movable partition engaged with and movable along a longitudinal track and a lead drive box coupled to the movable partition and engaged with the track. The lead drive box is configured to move along the track and move the movable partition along the track. The lead drive box includes a trolley for disposition within the track, a motor coupled to the lead drive box, and a rotatable drive member coupled to the lead drive box and the motor. The rotatable drive member engages an elongated drive member extending along the track to motivate the lead drive box and the movable partition attached thereto along the track when engaged with the motor and the motor is rotating. An electronics module disposed within the lead drive box is configured for controlling operation of the motor responsive to signals originating from sources carried by the lead drive box.

Abstract: The present invention advantageously provides a motorized roller shade that includes a shade conduit having an outer surface upon which a shade is attached and an inner surface defining an inner cavity. The motorized shade also comprises a motor disposed within the inner cavity along with a controller coupled to the motor that controls the motor. The motorized roller further comprises a power supply sleeve having an interior space, wherein the power supply sleeve is disposed within the inner cavity, wherein the power supply sleeve is coupled to the motor. The sleeve may be accessed by an access port that extends between the outer surface and the inner surface.

Abstract: A method for operating a window cover utilizes an extendible window cover having a first rail, a second rail and a pair of lift cords. The first and second rails of the window cover are movable relative to each other. According to the method, at least one of the first rail and the second rail is moved in a first direction to cause the lift cords to unwind from the lift cord pulleys, thereby rotating a lift cord pulley shaft and a set of gears. Further, at least one of the first rail and the second rail is moved in a second direction to cause the lift cords to wind on the lift cord pulleys, with the lift cord pulley shaft rotating in an opposite direction.

Abstract: A curtain assembly comprises a rotatable drive element wherein at least one helical guide structure is formed on, or into, the outer surface of the drive element. A drive attachment element having a structure that communicates with the helical guide structure to move the drive attachment element axially along the drive element when the drive element is rotated. Specific embodiments incorporate either a manual or motor-driven rotation assembly for rotating the drive element. Further specific embodiments involve a helical guide structure that comprises a helical groove and a structure that comprises a tooth that engages with the helical groove.

Abstract: A covering for architectural openings includes a cord drive with a pulley that is supported by a bearing surface which lies in the plane of the cord.

Abstract: An apparatus and method associated with the extension and retraction of a covering for an architectural opening. More particularly, an apparatus and method which monitors the extension of a shade to control the extension and position when the extension motion of the shade is interrupted.

Abstract: Movable partition systems include a drive mechanism including a motor positioned at least partially on a side of a track opposite a movable partition. Automatically movable partition systems include a movable partition movable along a track and a motor configured to move the movable partition, the motor positioned on a side of the track opposite the movable partition. Methods of installing a movable partition system include coupling a movable partition to a track, positioning a drive mechanism at least partially on a side of the track opposite the movable partition, and coupling an elongated drive member to the movable partition. Methods of moving a movable partition along a track include actuating a drive mechanism positioned at least substantially in a header recess. Drive modules for a movable partition system and other methods of installing a movable partition system including attaching a motor to a section of track are also disclosed.

Abstract: A battery-powered motorized window treatment for controlling the position of a covering material includes a motor drive unit having a belt drive. The motor drive includes a motor for rotating a drive shaft to thus raise and lower the covering material and is powered by one or more batteries. The belt drive includes a belt that surrounds a first pulley coupled to the motor and a second pulley, which operates to rotate the drive shaft. The belt drive isolates noise generated by the motor from the gears and parts of the motor drive unit and the motorized window treatment. The belt drive includes rollers for holding the belt on the pulleys, and the belt is sized to reduce the load on the motor, such that the motor draws less current from the batteries. As a result, the batteries have a much longer lifetime than those of a typical prior art battery-powered motorized window treatment.

Abstract: Example architectural opening coverings powered by rotary motors are described. An example architectural opening covering apparatus includes a rotatable member, a covering mounted to the rotatable member, a motor having a drive shaft which is capable of rotating the rotatable member in a first direction to raise the covering and in a second direction opposite the first direction to lower the covering, and a drive shaft coupling substantially preventing the motor from applying torque in the second direction.

Abstract: Wire supports for use with a movable partition system comprise a cantilever member configured for connection to a panel of a movable partition. A wire-supporting member through which wire may be inserted is rotatably connected to the cantilever member. Movable partition systems comprise a movable partition comprising at least two sheets of panels extending at least substantially parallel to one another and laterally distanced from one another to define an interior space between the at least two sheets of panels. At least one wire support disposed in the interior space between a proximal end and a distal end of the at least two movable partitions comprises a cantilever member secured to at least one panel of one of the movable partitions and a wire-supporting member rotatably connected to the cantilever member at least partially supporting at least one wire inserted through the wire-supporting member.

Abstract: Movable partition systems include a movable partition coupled to and movable along a track. The movable partition may comprise at least two accordion folding sheets of panels, a motor carried by the movable partition, and at least one electronic component unit configured to control the motor. The electronic component unit may be carried by the movable partition and disposed between the sheets of folding panels. Methods of installing a movable partition system include coupling an electronic component box to a floating door jamb within a movable partition.

Abstract: A cordless window blind includes a headrail; a first bottom rail suspended from the headrail by a first cord and a second cord; a window covering disposed between the headrail and the first bottom rail and movable between a raised configuration and a lowered configuration; a drive actuator including a spring motor including a drive wheel, a driven wheel, and an elongated spring belt having a first end secured to the drive wheel and a second end secured to the driven wheel, wherein the spring belt includes a length with a tapered width. Further included are first and second spools having a conical circumferential surface around which the first and second cords are respectively wound when the window covering is in the raised configuration. Also included is a hinged valence arm.

Abstract: A method and device for winding venetian blinds or honeycomb blinds, one ends of said multi-strand lift cords are fixedly connected with the underbeam of the venetian blinds or honeycomb blinds, while the other ends pass through the slats of the venetian blinds or honeycomb blinds converge into a strand rope; and finally the strand rope is fixedly connected with a winding reel which is rotated to wind the rope to realize the action of winding. The winding method of “many cords in one” is used in the present invention. The purpose of controlling the whole set of venetian blinds or honeycomb blinds is achieved by controlling a rope with a winding reel. The venetian blinds or honeycomb blinds of the present invention with simpler structure, more convenient installation, longer operating life, better lifting balance of the blinds, more beautiful products, and less influences of the window size.

Abstract: A window shade comprises first and second rails, and a shading structure and a suspension cord connected between the first and second rails. The second rail includes a resistance balancing unit and a cord winding unit to which the suspension cord respectively connects. The resistance balancing unit comprises a housing having an abuttal surface, a pulley pivotally connected with the housing, and a torsion spring. The pulley has a winding portion around which the suspension cord is wrapped, and a shaft portion extending coaxial to the winding portion from a side thereof. The torsion spring is tightly mounted around the shaft portion and has at least one end. The pulley when rotating in one direction drives the end of the torsion spring to push against the abuttal surface of the housing, whereby the torsion spring loosens to allow rotation of the pulley relative to the torsion spring.