The invention relates to window coverings and more particularly to an operating system for controlling the operation of the window covering. A window covering may comprise a head rail from which a panel is suspended. The head rail may be mounted to a window frame or other architectural feature. The panel may be supported by lift cords to raise and lower the panel relative to the head rail. The raising and lowering of the panel may be controlled using pull cords or the raising and lowering of the panel may comprise a “cordless” system where the panel is raised and lowered by direct manipulation of the panel.
In some embodiments, an operating system for a window covering comprises at least one spring motor; at least one brake; at least one lift spool assembly; and an effective shaft operatively coupled to each of the at least one spring motor, the at least one brake, and the at least one lift spool assembly. The shaft synchronizes the at least one spring motor, the at least one brake, and the at least one lift spool assembly. The at least one brake comprises an outer race selectively coupled for rotation with the shaft by a one-way clutch where the outer race is in contact with an adjustable band brake.
The outer race may have a generally cylindrical shape that defines a cylindrical brake surface where the band brake is in contact with the brake surface. The one-way clutch may comprise an inner race that is fixed for rotation with the effective shaft and that is selectively coupled for rotation with the outer race. The one-way clutch may comprise at least one recess formed on the outer race that receives a ball bearing. The at least one recess may define a first position where when the ball bearing is located in the first position the inner race and outer race are decoupled such that the inner race is freely rotatable relative to the outer race. The at least one recesses may cooperate with the inner race to define a second position for receiving the ball bearing where when the ball bearing is located in the second position the inner race and the outer race are coupled together for simultaneous rotation in a first direction. The inner race may define an aperture that receives the shaft such that shaft extends through the inner race and the shaft and the inner race rotate together. The band brake may comprise a substantially cylindrical second brake surface that contacts the cylindrical brake surface of the outer race. The band brake may have a first free end and a second free end where the first free end and the second free end are movable toward and away from one another. An adjustment mechanism may move the first free end towards and away from and the second free end. A spring may move the first free end toward the second free end. A force applied by the band brake on the outer race may be adjustable. The band brake may be supported in a head rail and a force applied by the band brake on the outer race may be controlled by an adjustment mechanism where the adjustment mechanism is accessible through an aperture formed in the head rail. The one-way clutch may comprise a one-way needle bearing. The one-way needle bearing may be mounted for rotation with the outer race. The one-way needle bearing may comprise a plurality of needle bearings that receive the shaft.
In some embodiments, an operating system for a window covering comprises at least one spring motor, at least one brake; at least one lift spool assembly comprising a spool; and an effective shaft operatively coupled to each of the at least one spring motor, the at least one brake, and the spool such that the shaft and the spool rotate together. The spool comprises a sloped arcuate receiving end that receives a lift cord and that narrows to an opposite end. A first cord pusher comprises an angled surface that pushes the lift cord toward the opposite and a second cord pusher is spaced from the first cord pusher that pushes the lift cord toward the opposite end.
The spool may be mounted on a cradle that includes a surface arranged below the spool. The spool may be disposed over the surface a distance that is less than two times the diameter of the lift cord. The spool may be mounted on a cradle where the cradle supports the first cord pusher. The first cord pusher may be spaced a second distance from the spool approximately equal to or less than about one half the diameter of the lift cord. The spool may comprise a flange that extends radially from the receiving end where the flange extends from the spool a third distance that is approximately equal to or greater than about 1.5 times a diameter of the lift cord. The spool may comprise a flange that extends radially from the receiving end where the flange extends into a recessed area of the cradle and is disposed behind the first cord pusher such that a serpentine path is created between the receiving end and a distal end of the spool. A cover may cover a top portion of the spool. The cover may comprise a recess for receiving the flange. The cover may comprise the second cord pusher. The first cord pusher and the second cord pusher may be disposed such that the first cord pusher and the second cord pusher push the lift cord sequentially. The lift spool assembly may comprise a second spool where the spool and the second spool are operatively connected by a transmission such that the spool and the second spool rotate together.
In some embodiments, an operating system for a window covering comprises at least one spring motor, at least one brake, at least one lift spool assembly; and an effective shaft operatively coupled to each of the at least one spring motor, the at least one brake, and the at least one lift spool assembly to synchronize the at least one spring motor, at least one brake, and at least one lift spool assembly. The at least one spring motor is positionable at any unoccupied location on the shaft. The at least one spring motor applies a first force directly to the shaft at a first location along the shaft and the brake applies a brake force directly to the shaft at a second location along the shaft where the first location is spaced along the longitudinal axis of the shaft from the second location.
The at least one spring motor may comprise a first spring motor and a second spring motor where the second spring motor is positionable at any unoccupied location on the shaft. The first spring motor may be located at one end of the shaft. The first spring motor may be physically connected to the at least one brake. The at least one spring motor may comprise a first spring motor, a second spring motor and a third spring motor where the second spring motor and the third spring motor may be positionable at any unoccupied location on the shaft. The at least one lift spool assembly may comprise a spool connected to a panel by a lift cord such that rotation of the spool moves one end of the panel in a first direction and a second direction, and the at least one spring motor may substantially counterbalance the load of the panel on the lift cord where the force generated by the at least one spring motor is less than the load of the panel to allow the one end of the panel to move in one of the first direction and the second direction when the panel is released. A first keyed hole may be formed in the at least one spring motor, a second keyed hole may be formed in the at least one brake, and a third keyed hole may be formed in the at least one lift spool assembly such that the shaft may be inserted through the first keyed hole, the second keyed hole, and the third keyed hole. The at least one spring motor may comprise a first spool and a second spool and a spring wound on the first spool and the second spool where one of the first spool and the second spool define the first keyed hole. The at least one brake may comprise a one-way clutch that defines the second keyed hole. The at least one lift spool assembly may comprise a spool where the spool defines the third keyed hole.
In some embodiments, an operating system for a window covering comprises a spring motor, a brake; a lift spool assembly comprising a first spool and a second spool; and an effective shaft operatively coupled to each of the spring motor, the brake, and the first spool. The shaft is operatively coupled to the first spool such that the shaft and the first spool rotate together and the first spool and the second spool are operatively connected by a transmission such that the first spool drives the second spool.
The first spool and the second spool may rotate in opposite directions. The first spool may be connected to a lift cord and the second spool may be connected to the lift cord. The first spool may be connected to a lift cord section and the second spool may be connected to a lift cord section. A first gear may be mounted for rotation with the first spool and a second gear may be mounted for rotation with the second spool. The first gear may mesh with the second gear. The first gear may be mounted on the first spool and the second gear may be mounted on the second spool.
In some embodiments, a window covering comprises at least one spring motor, a brake, at least one lift spool assembly comprising a spool; an effective shaft connected to each of the at least one spring motor, the brake and the at least one lift spool assembly. The shaft synchronizes the at least one spring motor, the brake and the at least one lift spool assembly. The at least one spring motor, the brake, the at least one lift spool assembly and the effective shaft are mounted in a head rail. A lift cord is connected between the spool and the end of a panel such that rotation of the spool moves the end of the panel in a first direction and a second direction. The at least one spring motor substantially counterbalances the load of the panel on the lift cord such that the one end of the panel moves in one of the first direction and the second direction when the panel is released. The brake applies a brake force to the shaft that resists movement of the end of the panel in the one of the first direction and the second direction. The force is adjustable after the at least one spring motor, the at least one lift spool assembly, the brake and the effective shaft are mounted in a head rail.
The brake force may be controlled by an adjustment mechanism. The adjustment mechanism may be accessible through an aperture formed in the head rail. The adjustment mechanism may be accessible when the brake is in the head rail.
In some embodiments, a method of making an operating system for a window covering comprises: providing a panel having a size; selecting a determined number of motors based on the panel; providing a brake; providing at least one lift spool assembly comprising a spool connected to a panel by a lift cord such that rotation of the spool moves one end of the panel in a first direction and a second direction; interconnecting and synchronizing the determined number of motors, the brake, and the at least one lift spool assembly using a shaft and mounting the determined number of motors, the brake, the shaft and the at least one lift spool assembly in a head rail; adjusting a brake force applied by the brake to the shaft to stop the movement of the one end of the panel in the one of the first direction and the second direction after the brake is mounted in the head rail.
Embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like references numbers are used to refer to like elements throughout.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Relative terms such as “below” or “above” or “upper” or “lower” or “horizontal” or “vertical” or “top” or “bottom” or “front” or “rear” may be used herein to describe a relationship of one element, area or region to another element, area or region as illustrated in the figures. It will be understood that these terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures.
Referring to
The shade panel 4 may be supported by lift cords 21 that are connected to or near the bottom edge of the panel 4 or to the bottom rail 19. The lift cords 21 may be retracted toward the head rail 18 to raise the shade or extended way from the head rail to lower the shade. The lift cords 21 may be operatively connected to the operating system that may be used to raise and lower the shade panel as will hereinafter be described. In one type of window covering, known as a privacy panel, each lift cord extends down the outside of one side of the panel, around the bottom of the panel and up the outside of the other side of the panel, as shown in
For a slatted blind, the slats 17 are also supported by a tilt cord 20 that functions to tilt the slats 17 between open positions where the slats 17 are spaced from one another and closed positions where the slats 17 are disposed in an abutting, overlapping manner. The tilt cord 20 may comprise a ladder cord as shown that supports the individual slats 17 where manipulation of the ladder cord results in the tilting of the slats 17 between an open position, closed positions and any intermediate position. The tilt cord 20 may be controlled by a user control 25 such as a control wand or cord that is manipulated by the user to adjust the opening and closing of the slats. Each tilt cord 20 may comprise a ladder cord that has a plurality of rungs 26 that are connected to and supported at each end by vertical support cords 28 and 30. A slat 17 rests on top of is otherwise supported by each rung 26. A drum or other control device may be rotated by a user using a control 25 such that the front vertical support cord 28 may be raised or lowered while the back vertical support cord 30 is simultaneously lowered or raised, respectively, to tilt the rungs 26 and the slats 17. Typically, the slats will be supported by two or more tilt cords 20 and two or more lift cords 21 depending upon the width of the window covering. While specific embodiments of a window covering are disclosed, the window covering may have a wide variety of constructions and configurations.
The operating system for controlling movement (raising and lowering) of the panel uses a cordless design where the raising and lowering of the panel is adjusted by manually moving the panel into position and then releasing the panel. The operating system, if balanced properly, holds the panel in position without the panel sagging (lowering) or creeping (rising). The operating system described herein may be used to control the movement of the bottom edge of a traditional panel and/or the top edge of a top down panel. The operating system uses spring motors, take-up spools and brakes to balance the load of the panel such that it may be moved into a desired position without sagging or creeping. It is difficult to balance the load of a window covering panel because the forces exerted by the spring motor, brake and system friction must be balanced against the supported load of the panel where the load of the panel supported by the lift cords varies as the panel is raised and lowered. As a result, cordless window coverings have been limited to custom blinds where the window covering may be weighted to balance against the forces generated by the spring motor, brake and system friction. The operating system of the invention is an improved cordless operating system that is more easily and effectively balanced and is less expensive than existing systems. As a result, the operating system of the invention may be used with size-in-store window coverings, lower cost window coverings as well as custom blinds. With size-in-store blinds the operating system is located such that the width of the window covering may be cut down to a desired size outside of the factory without adversely affecting the operating system. The operating system may be easily tuned to balance the size of the panel even after being cut down in a size-in-store operation.
An embodiment of the operating system of the invention is shown in
According to one embodiment, the brake 42 may be a one-way brake that applies a braking force on the shaft 46 that resists rotation of the shaft in the lowering direction such that sagging of the window covering is prevented. When a user raises the panel 4, the spring motors 40 wind the lift cords on the spools of the lift spool assemblies 44 and assist the user in raising the panel. When the user releases the panel 4, the brake 42 holds the shaft 46 in the desired position and prevents sagging of the panel. To lower the panel 4, the user pulls down on the bottom of the panel 4 (or on the top of the panel in a top down shade) to overcome the brake force generated by brake 42 and the forces generated by the spring motors 40. However, as described further herein, a one-way brake may be applied in the opposite direction to resist rotation of the shaft in the raising direction.
Referring to
Description of the spring motor 40 will be described with reference to
The spring motor 40 comprises a power spool 60 having a drum 62 for receiving a spring 64. Although not required in all embodiments, according to one embodiment, the power spool 60 also comprises a gear 66 mounted for rotation with the drum 62. Power spool 60 rotates about an axis formed by axles 70 that are supported in apertures 72 formed in side plates 68. A through hole 74 extends through the power spool 60 and defines the axis of rotation of the spool (
The spring motor 40 also comprises a take-up spool 80 including a drum 82 for receiving the spring 64. The take-up spool 80 is mounted on an idler gear 84 such that the take-up spool 80 and idler gear 84 may rotate both together and relative to one another as will hereinafter be described. The idler gear 84 comprises a gear 86 that is mounted to a post 88 where the post 88 is received in and extends through a sleeve 90 in drum 82 and forms the rotational axis of the drum 82 and the idler gear 84. The post 88 and sleeve 90 frictionally engage one another but may rotate relative to one another when the friction between the post 88 and sleeve 90 is overcome. Post 88 freely rotates about an axis formed by pins 92 that extend from side plates 68. The pins 92 engage a bore 92 that extends through the post 88. Other mounting mechanisms for rotatably mounting the idler gear 84 may also be used.
The power spool 60 and the idler gear 84 are mounted between the side plates 68 such that the power spool 60 and idler gear 84 may freely rotate. The power spool 60 and the idler gear 84 are positioned such that gear 66 engages gear 86. Spring 64 is wound on the power spool 60 and take-up spool 80 such that as the panel 4 is lowered the spring 64 is wound onto the power spool 60 and is unwound from the take-up spool 80. Energy is stored in the spring 64 as it is wound on the power spool 60. As the panel is raised the spring 64 unwinds from the power spool 60 back onto the take-up spool to rotate the shaft 46 and wind the lift cords 21 on the spools of lift spool assemblies 44.
According to one embodiment, the spring 64 may comprise a variable force spring and may be designed such that maximum torque is generated when the panel is fully raised and the load on the lift cords 21 from supporting the full weight of the panel is greatest and a minimum torque is generated when the panel 4 is fully lowered and the load on the lift cords from supporting the panel is lowest. Because the spring force is relatively low when the panel 4 is initially raised from the fully lowered position, the possibility exists that the spring 64 will “billow” around the take-up spool 80 rather than being tightly wound around the spool. To prevent the billowing of the spring 64 the power spool 60 and take-up spool 80 may be geared together by gears 66 and 86 such that the take-up spool 80 is forced to rotate and wind the spring 64 when the panel 4 is initially raised. However, because the speed at which the spring 46 moves does not match the rotational speed of the take-up spool 80 over the entire range of motion, the take-up spool 80 and power spool 60 may spin at different speeds over the range of motion. Therefore, it may be preferable to allow the drums 82 and 62 to spin independently of one another over at least portions of the range of motion of the panel. By mounting the take-up spool drum 82 on post 88 of idler gear 84, the drum 82 may spin freely relative to the idler gear 84 when the friction between the idler gear 84 and drum 82 is overcome to allow independent rotation of the drum 80 relative to power spool 60. If the spring 64 does not billow or the billowing of the spring does not cause binding or otherwise interfere with the operation of the motor, the idler gear 84 and/or drive gear 66 may be eliminated and take-up spool 80 may be allowed to rotate independently of power spool 60 throughout the entire range of motion.
The arrangement of the spring 64 will be described. According to some embodiments, it may be desired to approximately match the output torque of the spring 64 to the load supported by the spring motor 40 over the entire range of motion of the panel 4 between the fully raised position and the fully lowered position. In a typical window covering the load supported by the lift cords increases as the panel is raised and decreases as the panel is lowered. This is because as the panel is raised the panel stacks on top of itself and on the bottom rail and the stacked load is supported by the lift cords. As the panel is lowered the panel unstacks such that more of the load of the panel is transferred to and supported by the tilt cords and/or head rail, depending on the style of window covering, and less of the load is supported by the lift cords. Thus, it may be desirable to increase the torque output of the spring motor 40 as the panel is raised and to decrease the torque output as the panel is lowered.
To provide a variable force output, a variable force spring 64 may be used. According to one embodiment, the natural diameter of the spring 64 varies along the length of the spring to produce a variable output. The variable force spring can be created by winding a metal strip into a coil where the spring has a smaller diameter on the inside end of the coil (higher spring force) and an increasingly larger diameter to the outside end of the coil (lower spring force). However, if the spring 64 is mounted on the motor 40 as coiled the smaller diameter would be on the inside of the spring coil and the torque output by the motor 40 would increase as the coil is extended (i.e. the torque would increase as the panel is lowered). This is the opposite force curve desired in the operation of a window covering. To achieve the desired force curve, the spring is mounted on the spools in a reverse manner such that the larger natural diameter is on the inside end of the coil at end 64a and the smaller natural diameter is on the outside end of the coil at end 64b (
It is appreciated that a variable force spring 64 can be generated in a number of other manners, which may also be utilized in the embodiments described herein. For example, a variable force spring may be formed by tapering the spring from a first end of the spring to a second end of the spring such that the thickness and/or width of the spring varies (rather than or in addition to its curvature) along its length. Another example of a variable force spring comprises a spring having a series of apertures or other cutouts formed along the length of the spring where the cutouts increase in size from a first end of the spring to a second end of the spring. Other embodiments for creating a variable force spring may also be used.
In one embodiment, to create the spring motor 40, the coil spring 64 is wrapped on the storage spool 80 and the storage spool 80 and power spool 60 are mounted between the side plates 68. The spring 64 is then reverse wrapped on the power spool 80 to preload the spring. The power spool 80 is held in the reversed wrap condition such as by inserting a pin 99 that engages the power spool 60 and one of the side plates 68. The reverse wrapped (preloaded) spring motor 40 is inserted into the head rail of the blind and is connected to the shaft 46 when the panel 4 is in the in the fully lowered position.
It may be difficult to construct the spring motor 40 such that the torque generated by the spring motor exactly matches the varying load of the panel 4. As a result, the spring motor 40 may be designed such that it is intentionally either underpowered or overpowered relative to the load of the panel. If the spring motor 40 is slightly underpowered the panel will tend to sag and if the spring motor is slightly overpowered the panel will tend to creep. A one-way brake 42 is used to prevent the sagging or creeping of the panel 4 depending on whether an overpowered or underpowered spring motor is used. In the illustrated embodiment the spring motor 40 is designed such that the force generated by the spring motor is slightly underpowered relative to the load of the panel 4 and the brake 42 is used to prevent sagging. The operating system of the invention may also be used with an overpowered spring motor where the brake function is reversed to prevent creeping.
One embodiment of a brake 42 suitable for use in the operating system of the invention is shown in
The spring motor 40 and brake 42 may also be formed as separate units that are independently mounted to the shaft 46. The brake 42 comprises an outer race 106 and an inner race 108 where the inner race 108 is connected to the outer race 106 using a one-way clutch. The inner race 108 is mounted for rotation with the shaft 46 and the outer race 106 is in contact with an adjustable band brake 110. The brake force may be applied to the outer race using a mechanism other than a band brake such as a clamp brake, brake shoe and the like.
Referring to
The inner race 108 is rotatably mounted in the bore 118 of the outer race 106 such that the inner race 108 may rotate relative to the outer race 106. The inner race 108 comprises a first section 108a and a second section 108b that together form the inner race (
A ball bearing 128 is positioned in the each of the spaces defined between the outer recesses 122, 124 and 126 and the inner recesses 144, 146 and 148. The ball bearings 128 are trapped between the web 116 of the outer race 106 and the side walls 120 of the inner race but are free to move in the spaces defined by the inner recesses 144, 146 and 148 and the outer recesses 122, 124 and 126.
A brake member is provided that contacts the brake surface 114 on outer race 106 to apply the braking force to the system. Referring to
Reference will be made to
When the panel is lowered the shaft 46 rotates counterclockwise as shown in
To assemble the brake 42, three ball bearings 128 are inserted into the recesses 122, 124 and 126 on a first side of the outer race 106. The first inner race section 108a is inserted into the outer race 106 to hold the three ball bearings in place. The assembly is flipped over and three ball bearings are inserted into the recesses 122, 124 and 126 on the second side of the outer race 106. The second inner race section 108b is inserted into the outer race 106 to hold the three ball bearings in place. The assembled inner race 108 and outer race 106 are inserted into the band brake 110 and the brake assembly is trapped between the side plates 100 and 102. In the illustrated embodiment the side plates 100 and 102 are snap fit together by inserting pins 101 formed on one of the side plates into mating receptacles 103 formed on the other side plate. The side plates may also be connected using separate fasteners, adhesive or the like.
An alternate embodiment of the brake is shown in
An alternate embodiment of a one-way brake is shown in
The one-way clutch comprises a one-way needle bearing assembly 318 that is trapped between the blocks 302 and 304 such that the pressure created by the clamping action of the blocks 302 and 304 is applied to the external brake surface 321 of the needle bearing assembly 318. The blocks 302 and 304 may include cradles or brake surfaces 320 or other similar structures for retaining the needle bearing assembly 318 that act on the external brake surface 321 of the needle bearing assembly. The needle bearing assembly 318 comprises an annular housing 322. A plurality of one-way needle bearings 324 are positioned around the interior opening of housing 322. The one-way needle bearings 324 may rotate in a first direction relative to the housing 322 but are prevented from rotating in the opposite direction. The shaft 46 is inserted through the needle bearing assembly 318 such that it engages and rides on the needle bearings 324. When the shaft 46 is rotated in a first direction (corresponding to raising the panel) the needle bearings 324 are free to rotate relative to the housing 322 and the brake has no effect on the rotation of shaft 46. When the shaft is rotated in a second direction (corresponding to lowering the panel) the needle bearings 324 are locked between shaft 46 and the housing 322 causing the housing 322 to rotate with shaft 46 against the brake force generated by the blocks 302 and 304 on the brake surface 321.
Another embodiment of a one-way brake is shown in
Another embodiment of a one-way brake is shown in
One embodiment of a lift spool system 44 suitable for use in the operating system of the invention is shown in
Referring to
The base 170 includes a first offset surface 176 and a second offset surface 178 arranged below spools 160 and 164, respectively. The spools 160 and 164 are arranged such that the drive spool 160 is disposed over one offset surface 176 and the driven spool 164 is disposed over the other offset surface 178. The offset surfaces 176 and 178 are disposed a distance from the surfaces of the spools 160 and 164 that, in one embodiment, can be less than two times the diameter of the lift cords to guide the lift cords onto the spools in a non-overlapping manner. The spools 160 and 164 are formed with a sloped arcuate receiving end 192, which may have an arcuate shape in one embodiment, at the end of the spool that receives the lift cord. The receiving end 192 narrows to opposite end 194 such that the spools have a tapered shape. The arcuate sections of spools 160 and 164 force the cords to slip downward toward the slightly tapered end 194 of the spools. Decreasing the surface friction of the spool material or increasing the slope of the arcuate section makes the cord slide down the spool more easily. However, if the curvature of the arcuate section is too steep the cord may be more likely to wind on top of itself. The slight taper of the spools ensures that the cord sections already wrapped on the spool remain looser than the cord sections being wrapped on the spools to allow the cords to be pushed down the spool with minimum force with each winding of the cord. The tapered shape of the spools 160 and 164 facilitates the orderly winding of the lift cords on the spools such that as each cord is wound on a spool the cord is moved from the wider receiving end 192 toward the narrow end 194 such that the cord does not wind on itself.
Referring to
To further maintain the cord on the spools a cradle cover 720 may be provided on the top of the spools that is spaced from the spools a distance such that the cord is constrained to wrap onto the spools rather than jumping off the spools as shown in
The illustrated embodiment shows a two spool arrangement that is used with a privacy-type lift cord. A privacy-type lift cord is wound around one spool, extends down the front side of the panel, wraps under or through the bottom rail and extends up the back side of the panel 4 where it is wound around the second spool as shown in
Assembly of the operating system will now be described according to one example embodiment. A head rail 18 is provided that may have an interior space for receiving the operating system as shown in
As previously described, the brake 42 and one of the motors 40 may be combined into a single unit if desired. In one embodiment, the components of the system snap into the head rail such that separate fasteners are not required, however, other mounting mechanisms including the use of separate fasteners may be used. While an embodiment of a lift system is shown in
The lift spool systems 44 are arranged in a one to one relationship with the lift cords 21 such that for a typical window covering where two lift cords are used, two lift spool systems 44 are also used. For larger window coverings, three or more lift cords may be used and a corresponding number of lift spool systems 44 are also used. Each lift spool system 44 can be arranged proximate to (i.e. approximately above) the associated lift cord such that the lift cord is wrapped onto the spool at the large diameter receiving end 192 of the spool. Apertures are provided in the head rail 18 and cradle 168 to receive the lift cords.
The assembly of a privacy-type lift cords will now be described with reference to
A first end of the lift cord 21 is threaded through an aperture in the head rail and through an aperture 714 in the lift spool cradle 168. The cord is operatively coupled to the drive spool 160 such that rotation of the spool winds the lift cord on the spool. In one embodiment a knot is tied in the first end of the lift cord 21 and the cord is inserted into a slot 199 on the drive spool 160 (
The panel 4 is then suspended vertically from the head rail 18 by the lift cords. The lift cords 21 are wound on the spools 160 and 164 to take the slack out of the lift cords such that the panel is suspended at its full length and there is no slack in the lift cords. The shaft 46 is inserted through the mating keyed receptacles on the motor(s) 40, brake(s) 42 and drive spool(s) 160 to create the lift system as shown, for example, in
In addition to adjusting the brake force during manufacture of the window covering or as part of a size-in-store operation the adjustment mechanism allows a user to adjust the braking force during use of the window covering. For example, a user may adjust the brake force if the system ever becomes out of balance during use. For example, if the force output by the spring motors changes over time, the user can loosen or tighten the brake to accommodate the change in motor output without returning the blind to the manufacturer or even removing the blind from the window. Moreover the adjustment of the brake force may be used to adjust the operating parameters of the window covering. For example if the user does not require the window covering to be raised completely to the head rail the brake force may be lowered. One example of such a use would be in a situation where an eight foot tall window covering is installed but a user can only reach six feet. As a result the user will not be raising the window covering the full eight foot height of the panel. Because the panel is not fully raised the full eight feet the brake never needs to hold the full weight of the stacked panel. As a result the brake force may be lowered such that the maximum brake force applied to the system is set to hold six feet of panel rather than the maximum eight feet. The user may want to lower the maximum brake force in this situation to lower the force that needs to be applied to the panel by the user to lower the panel.
For a top down shade, where the top edge of the panel may be raised and lowered relative to the head rail, the operating system may be connected to the top edge of the panel 4 to control the movement of the top edge of the panel. In top down shades the top edge of the panel may include a middle rail. The lift cords are connected to the top edge or middle rail rather than to the bottom edge of the panel or bottom rail. In a top down shade the load on the system increases as the panel is raised because as the top of the panel is raised more of the shade panel is suspended from the top rail (rather than resting on the bottom rail) such that the operating system operates in the same manner to support the load and facilitate the raising and lowering of the top edge of the panel as previously described. “Top down/bottom up” shades are also known where the top edge/middle rail and the bottom edge/bottom rail are independently movable. In such systems two operating systems may be used where one operating system is connected to the top edge/middle rail and the other operating system is connected to the bottom edge/bottom rail. The two operating systems operate independently to control the movement of the panel.
An example embodiment of a top down/bottom up window covering is shown in
Referring to
In one embodiment a single shaft 46 extending through all of the components may be used; however, in other embodiments the shaft may be provided as multiple segments where a segment extends between the components such as between the motors, cradle, and brake. For example, a first shaft segment may extend from the left end of the head rail through spool system 44a and motor 40a and terminate inside of the drive spool of spool system 44b where the shaft is operatively coupled to the drive spool. A second shaft segment may extend from, and be operatively coupled to, the drive spool of spool system 44b and extend through the remaining components. In such an embodiment, the shaft segments function as a single shaft because the shaft segments are operatively coupled to one another by the common component(s) (the drive spool of spool system 44b in the present example). While a system with a single shaft 46 and a two segment shaft have been described other embodiments using a greater number of shaft segments may be used where the shaft segments are coupled in series by the common components such that the shaft segments are operatively coupled to one another to form an effective shaft that synchronizes the movement of the components.
All of the components of the system may be disposed inside of the ends of the head rail 18 such that the head rail extends beyond each end of the lift system a desired length L. In one embodiment length L may be approximately 3 inches; however, length L may be varied to accommodate various cut down lengths. The length the head rail extends beyond the ends of the operating system may be cut off in a size-in-store operation such that the window covering may be sized to a customer desired size. While size-in-store systems and cutting machines are known, the operating system of the invention allows a window covering with a cordless operating system to be used in a size-in-store system.
Because the components are modular and independent from one another, the motors 40 may be positioned anywhere along the length of the shaft 46 and the motors do not have to be co-located with one another. This provides an advantage because the torques exerted on the shaft 46 by the motors 40 may be spread out along the length of the shaft 46 to shorten the length of the shaft over which the torques are applied. In systems that place all of the motors at one end of the shaft significant twisting forces are accumulated over the length of the shaft. In the system of the invention, where the motors 40 may be placed anywhere along the length of the shaft 46, the load accumulation may be minimized. For example, if four lift spool systems 44 are used and three motors 40 are required to handle the load of the panel 4, the motors 40 may be alternated with the lift spool systems 44 along the length of the shaft 46 such that the torsional load on the shaft is minimized. Moreover, the number of motors 40 is not tied to the number of lift cords 21, lift spool systems 44 or brakes 42 such that the motors, lift cords, lift spool systems and brakes may be provided as needed.
Additional lift spool systems 44, brakes 42 and motors 40 may also be added to the system by simply adding more components into the head rail before inserting the shaft 46. As a result, the system may be easily scaled to work with larger or smaller or heavier or lighter window coverings. Because all of the components are synchronized through the shaft 46, it is possible to scale up the system by multiplying the number of motors 40 by the factor of the window width. For example, for a particular window covering style the motor may be sized for a particular span (e.g. 12 inches) and then propagated in multiples of that basic span to create larger span window coverings or window coverings having a greater mass (e.g. panel mass may change with slatted blind compositions, such as real wood, faux wood, composites etc.). The length of the shaft 46 may be increased for larger and/or heavier window coverings to accommodate additional components but because the components may be located at any location along the length of the shaft excessive twisting loads are not created on the shaft. The operating system may also be scaled to very short spans, as small as 6 inches, by locating all of the components in close proximity to one another. The modular system simplifies the manufacture of the window covering, is scalable, allows easy replacement of components and is relatively inexpensive.
The operating system also accommodates a tilt system for use with slatted blinds where the slats may be tilted for light control and privacy in addition to being raised and lowered. The tilt system may be omitted in window coverings such as cellular shades or Roman shades or the like where tilting of slats is not required. Referring to
With any shade panel it is desirable to have the bottom edge of the panel and/or bottom rail level during use of the window covering. When the panel is in any raised position, the levelness of the bottom edge of the panel and/or bottom rail is directly related to the variation in lengths of the lift cords spanning the width of the window covering. Where one lift cord is shorter than the other lift cord, the bottom of the panel will angle upward toward the shorter lift cord. A system for equalizing the lengths of the lift cords to provide a level bottom rail is described with reference to
An adjustment assembly 200 (
Referring to
To use the adjustment assembly, a bore or hole 203 is formed on the bottom rail 19 that is dimensioned to receive the sleeve anchor 202. Typically, the sleeve anchor 202 is mounted on the bottom rail 19 so as to be vertically aligned with the lift spool assembly 44 and the lift cord 21. The portion of the lift cord 21 that passes below or through the bottom rail 19 (
The window covering is then supported from the head rail and the bottom rail 19 is checked for level. If it is not level, the longer lift cord (the lower end of the bottom rail) is adjusted. The length of the cord is adjusted by rotating the plug 216 in the sleeve anchor 202. As the plug 216 rotates, the cord 21 is wrapped around the plug 216 in drum 224 to shorten its effective length. The plugs 216 are rotated until the bottom rail is level. As the plug 216 is rotated projections 223 on the plug 216 ratchet over the projections 212 on the anchor sleeve 202 such that when the plug 216 is released the engaging projections hold the plug 216 in position relative to the anchor sleeve 202. Each “click” of the plug 216 over projections 212 may shorten or lengthen the lift cord a predetermined distance such as one-eighth of an inch such that if the user needs to shorten a lift cord a quarter of an inch the plug 216 is rotated two “clicks”. The ratcheting movement may provide tactile and audible feedback to the user. Once the lift cords are properly adjusted, the bottom of the tilt cord (if a tilt cord is used such as in a slatted blind) is inserted into one of the slots 226 or 227 on the head 220 of the plug 216. A cap 230 is then inserted over and engages the head 220 of the plug 216 and the rim 222 of sleeve anchor 202. The cap 230 holds the tilt cord in place and fixes the position of the plug 216 relative to the sleeve anchor 202. The cap 230 is provided with cross-members 231 that engage slots 226 and 227 and tabs 232 that engage mating surfaces on the sleeve anchor 202 to connect these components together. The cap 230 is also provided with slots 234 for receiving the tilt cords.
Specific embodiments of an invention are disclosed herein. One of ordinary skill in the art will recognize that the invention has other applications in other environments. Many embodiments are possible. The following claims are in no way intended to limit the scope of the invention to the specific embodiments described above.
This application claims benefit of priority under 35 U.S.C. §119(e) to the filing date of U.S. Provisional Application No. 61/671,212, as filed on Jul. 13, 2012, which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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61671212 | Jul 2012 | US |