JP2012026262A - Self-raising window covering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-raising window covering and its control mechanism.SOLUTION: String winding assemblies 20 and 22 are mounted coaxially on a drive shaft and include winding drums 24 and 26 and a rotatable positioning component. The winding drums 24 and 26 are operatively connected to a pulling string 42 and have a tapered portion. The positioning component is designed to move the string winding assemblies 20 and 22 laterally along a drive shaft 18 during a rotation. The string winding assemblies 20 and 22 are designed to convert the rotational force of the drive shaft 18 to a pulling force of the pulling string 42, and the pulling force is greater than a downward force exerted by a shade component 38 and a bottom crossbar 40 throughout the range of opening and closing. A clutch component 36 or engaging component is operatively connected to the drive shaft 18 and designed to releasably engage the drive shaft on a desired position.

Description

  The present invention relates to a window covering that can be raised without opening the window covering itself or the control mechanism when it is opened. In particular, the present invention applies an upward force of sufficient magnitude to raise the shade member and bottom rung to the shade member and bottom rung without applying any additional force by the user when raising. The present invention relates to a window covering having a control mechanism.

  Window shades and window coverings can be found in many applications and are used to adjust the amount of light entering the room and to provide an aesthetic appeal to the decoration. Such window shades and window coverings take a number of forms, including rollr shades, roman shades, venetian blinds, and cellular shades. Conventional cellular or pleated shades use a cord lock or transmission mechanism to raise and lower the window covering and place it in the desired position. In window coverings that use a string lock, the string extends through the folded fabric, traverses the inside of the upper rung, passes through the securing mechanism and exits. Other cellular shades include a continuous loop string that is pulled by the user to raise and lower the transmission mechanism and the window shade. Roman shades and Venetian blinds also tend to have lifting strings fixed to the lower bar or bottom rung.

  There are several drawbacks to these designs. The string has the potential danger of the child becoming entangled or suffocated by the exposed control string. The laces are also aesthetics of window coverings in that they must extend around the surface of the window covering and be wrapped around a hook when the blind is opened, or simply left on the floor. Tend to disturb. In addition, in window coverings that use a string lock, as a result of raising and lowering the window covering, the string is subject to significant wear due to friction against the surface.

  Another window covering that works without a string is a typical roll shade. These roll shades are provided with a torsion coil spring type pull-in mechanism, to which a roller is attached, combined with a clutch or a locking mechanism, and the shade is collected by being wound on the roller. In operation, the roll shade is pulled down to the desired position by the user and secured in that position by a clutch or locking mechanism. To release the lock and allow the shade to rise, the user typically pulls the shade's bottom rung sufficiently to extend the shade sufficiently to release the internal clutch or locking mechanism. When the clutch or locking mechanism is released and the user releases the shade, the shade is retracted using a torsion spring driven retraction mechanism. However, known roll shades can only function on flat shade materials that can be rolled up tightly to a limited location.

  The mechanisms used in such roll shades are not compatible with other window coverings such as cellular shades, venetian blinds, and roman shades. As the roll shade is raised, the amount of shade to be pulled is reduced so that the constant load torsion spring member can apply the necessary hoisting force or upward force throughout the open range. In contrast, similar lifting mechanisms are typically not suitable for cellular shades, venetian blinds, and roman shades. In this type of window covering, the shade member material is typically collected by raising the bottom member, such as the bottom rung, so that as the window covering rises, more weight is placed on the bottom member. To gather. The reason for this is that as the bottom rung rises, shade material or shade members gradually accumulate on the bottom rung and increase the load applied to the lift mechanism.

  To cope with this increasing weight, very strong torsion springs are used to accommodate the maximum weight of the shade. However, one drawback of this approach is that the window covering can be stored too quickly and out of control. One attempt to address this problem can be found in Welfolder US Pat. No. 6,666,252. This patent teaches the use of a fluid brake to control the pull string pull rate throughout the pulling process. Another approach already in use is shown in Todd US Pat. No. 6,056,036, which uses a mechanical friction member to continuously slow the retraction. One problem with these approaches is that the spring being used exerts a force that makes it difficult for the user to overcome when attempting to lower the shade. Excessive pulling force by the user often leads to breakage of the window covering.

  As an alternative, variable force springs are used. Such variable force springs are quite complex to use and manufacture.

  Accordingly, there is a need for a window covering lifting mechanism for window coverings such as Venetian blinds, cellular shades, and roman shades that automatically lifts and overcomes the above problems. Existing.

  The present invention relates to a self-lifting window covering and a control mechanism for the window covering. Specifically, the window covering is operatively connected at the top rung, shade member (such as a cellular panel, blind slat, or roll shade material), bottom rung, first end to the lower rung. Self-raising window covering with one pull string and control mechanism. The upper rung can define an elongated channel in which the control mechanism is disposed. In some embodiments, the control mechanism includes a drive shaft and a drive unit operably connected to the drive shaft. The drive unit may be a constant load spring, but is configured to provide a substantially constant rotational force on the drive shaft.

  In addition, at least one string winding assembly is provided in coaxial relation with the drive shaft. Typically, the number of string winding assemblies is the same as the number of lifting strings. However, in some cases, a single string take-up assembly may be configured to operate on multiple strings. The string take-up assembly may comprise at least one take-up drum having a tapered portion operatively connected to the second end of the pull-up string. Further, the string take-up assembly includes a rotatable positioning member for moving the string take-up assembly laterally along the drive shaft when the positioning member rotates. In a preferred embodiment, the positioning member is a threaded tubular member connected to the take-up drum. The string take-up assembly is configured to convert the rotational force of the drive shaft into a lifting string lifting force, where the lifting force is applied by the shade member and the bottom rung throughout the range of opening and closing. Greater than the total downward force being generated. In a preferred embodiment, the string take-up assembly is secured to the drive shaft for rotation by a hub member configured to engage the string take-up assembly and the drive shaft. The hub member may be in sliding relationship with the tapered portion of the string winding assembly.

  Further, the clutch member or the locking member is operably connected to the drive shaft, and is configured to releasably lock the drive shaft at a desired position. In a preferred embodiment, the clutch member is arranged coaxially with respect to the drive shaft, and is connected to the reciprocating body that can move between the release position and the locking position, and the reciprocating body is held with respect to the drive shaft. And a spring member operable to reinforce or relieve. The reciprocating body is in close contact with the drive shaft in order to prevent rotation of the drive shaft against the rotational force applied by the drive unit in the locked position, and is applied by the drive unit in the release position. The spring member is configured to be loosened with respect to the drive shaft in order to enable rotation of the drive shaft by the rotational force generated.

FIG. 3 is a partial cutaway perspective view of a preferred embodiment of a window covering according to the present invention. It is a disassembled perspective view of the single spring coil drive unit of FIG. It is side surface sectional drawing of the single spring coil drive unit of FIG. It is side surface sectional drawing of another single spring coil drive unit. It is side surface sectional drawing of a double spring type drive unit. It is side surface sectional drawing of another double spring type drive unit. FIG. 2 is an exploded perspective view of the string take-up assembly shown in FIG. 1. It is a front view of the state where the window covering of FIG. It is a front view of the state opened to the middle of the window covering of FIG. 1, and an upper crosspiece is shown by the cross section. FIG. 6 is a perspective view of a preferred clutch member when the window covering is in a fully raised position. It is sectional drawing of the clutch member of FIG. 9A. FIG. 9B is a perspective view of the clutch member of FIG. 9A when the user pulls down the window covering. It is sectional drawing of the clutch member of FIG. 10A. FIG. 9B is a perspective view of the clutch member of FIG. 9A when the user releases the window covering. It is sectional drawing of the clutch member of FIG. 11A. FIG. 9B is a perspective view of the clutch member of FIG. 9A when the user pulls down the window covering to release the clutch member. It is sectional drawing of the clutch member of FIG. 12A. It is a perspective view of the clutch member of Drawing 9A when a window covering raises automatically. It is sectional drawing of the clutch member of FIG. 13A. FIG. 6 is a perspective view of another embodiment of a window covering according to the present invention, in which a speed reduction member is provided. FIG. 15 is a side cross-sectional view of the speed reduction member of FIG. 14 with the speed reduction member being separated from one string take-up assembly. FIG. 15 is a side cross-sectional view of the speed reduction member of FIG. 14 with the speed reduction member engaging a single string take-up assembly. It is side surface sectional drawing of the deceleration member of FIG. 14 when a window covering is pulled up completely.

  Although the present invention is disclosed herein, many different types of embodiments of the present invention are readily possible. Preferred embodiments of the invention are illustrated in the drawings and are described in detail below. However, the disclosure herein is merely illustrative of the principles and features of the present invention and is not intended to limit the present invention to the embodiments shown herein.

  Referring to FIG. 1, an embodiment of a self-raising window covering 10 according to the present invention is shown. An upper rung 12 is provided that defines a channel. A pair of drive units such as spring units 14 and 16 are attached coaxially about the drive shaft 18. Further, a string take-up assembly 20 and 22 is attached to the drive shaft 18. Each of the string take-up assemblies 20 and 22 includes frustoconical take-up drums 24 and 26 and threaded tubular members 32 and 34, respectively. One end of pull-up cords 28 and 30 (shown wound on take-up drums 24 and 26) are secured to take-up drums 24 and 26. In this embodiment, a clutch 36 is further provided and is coaxially attached to the drive shaft 18. Each of these components will be described in more detail later. In addition, the window covering 10 includes a shade member such as a cellular shade material 38 and a bottom member such as a bottom rung 40. The term “string” as used herein is suitable for hanging and supporting a shade member and can be wound or pulled out to stretch or retract the shade member, a cord, a strip. ), Ribbons, strings, or similar flexible and elongated members. In addition, a relatively short length of strap 42 can be provided to allow the user to pull down the window covering and to release the clutch and automatically store the window covering as will be described in more detail below. .

  Referring to FIG. 2, a preferred embodiment of the spring unit 14 is shown. The spring unit 14 includes a spring casing 42, a spring shaft 44, a constant load coil spring 46, and a cover 48. The coil spring 46 and the spring shaft 44 are fixed in the casing 42, and the casing 42 is closed by a cover 48. A first end 50 of the coil spring 46 is fixed to the spring shaft 44, and the spring shaft 44 is coaxially connected to the drive shaft 18 (FIG. 1). In this preferred embodiment, the coil spring is configured to provide sufficient rotational force to drive shaft 18 and take-up drums 24 and 26 to raise the shade member and bottom rung. Other alternative embodiments of the spring unit are possible, such as the embodiments shown in FIGS.

  For example, the suitable spring unit 114 shown in FIG. 3 is fixed to the first spring shaft 142 with the first end connected to the drive shaft 18 shown in FIG. 1, and the second end is the first A wound spring member 146 may be provided that is secured to a second spring shaft 144 that is offset from the spring shaft 142. The relaxed winding spring 146 can first be wound around the second spring shaft 114. As the shade member is pulled downward, the winding spring 146 can be withdrawn from the second spring shaft 144 and gradually wrapped around the first spring shaft 146. This configuration of the spring unit 114 is considered suitable when the winding spring 146 used has a large length to allow a longer extension range for the shade member.

  FIG. 4 shows another suitable spring unit 214 that is similar to the embodiment shown in FIG. 3 except that the second end of the wrap spring is not connected to the second spring shaft. Yes. Instead, the winding spring 246 is wound onto itself at the second end, while the first end 252 of the winding spring 246 is only connected to the drive shaft 18 shown in FIG. Two spring shafts 218 are connected.

  Yet another suitable embodiment of the spring unit is shown in FIGS. In FIG. 5, the spring unit 314 includes an assembly of two wrap springs 346 and 348 that can be used to provide a greater lifting force to the shade member. The first end of the first coil spring 346 is connected to the first spring shaft 344, and the first end of the second coil spring 348 is connected to the second spring shaft 345. Yes. The second end of the first winding spring 346 and the second end of the second winding spring 348 are located between the first and second spring shafts 344 and 345, respectively, to the drive shaft 18. It is connected to a third spring shaft 318 that is connected. As the shade member is pulled downward, the winding springs 346 and 348 are pulled out of the first and second spring shafts 344 and 345, respectively, and are gradually wound around the third spring shaft 318 and become larger on the drive shaft 18. A rising force can be applied. In FIG. 6, the illustrated embodiment is similar to that of FIG. 5, except that the two springs 446 and 448 that wrap around the shaft 418 connected to the drive shaft are not connected to the second spring shaft. Very similar to the embodiment shown. Each of the illustrated embodiments uses a spring as the drive mechanism for the drive unit, but it should be understood that any mechanism suitable for applying a rotational force to the drive shaft is available. It is.

  Referring again to FIG. 1, the rotational force applied to the drive shaft 18 causes the string winding assemblies 20 and 22 to rotate and translate to wind the strings 28 and 30, thereby causing the shade member 38 to move. , Pulled up vertically towards the upper rung 12. A preferred embodiment of the string winding assembly will be described in more detail with reference to FIG.

  The string take-up assembly 20 is coaxially attached to a drive shaft 18 that passes through a fixed housing composed of a frame 64 and an upper cover 65. The string winding assembly 20 includes a winding drum 24 and a rotary positioning member (such as a threaded tubular member 32) fixedly connected to one end of the winding drum 24. The string take-up assembly 20 is preferably configured to transmit relative rotational movement between the drive shaft 18 and the string take-up assembly 20, such as the adapter 60, while allowing relative translation between the two. It is attached to the drive shaft 18 via a hub member. In some embodiments, an adapter 60 with a through hole for mounting the drive shaft 18 can be coaxially mounted inside the central hole of the take-up drum 24. In order to transmit a rotational motion while allowing a smooth relative translation between the winding drum 24 and the adapter 60, radially inward from the surface of the central hole of the winding drum 24 on the outer peripheral surface of the adapter 60. Radial portions that contact the ribs protruding into the surface can be provided. In addition, a threaded tubular member 32 engages a toothed roller 66 that is rotatably mounted to a frame 64 and a bracket 68 that are rigidly secured to the upper rung 12. Thereby, while transmitting rotational motion between the drive shaft 18 and the string winding assembly 20, it is possible to enable smooth relative translation with little friction between the two. Furthermore, the engagement through the adapter 60 and the threaded tubular member 32 can improve the load support of suspended components such as the shade member 38 and the bottom rung 40, for example.

  The winding drum 24 is tapered and preferably in the shape of a truncated cone, and can be provided with striations or grooves to improve the gripping of the string 28 wound on the surface of the winding drum 24. The end of the pulling string (not shown) is fixed toward the end 62 having the larger diameter of the winding drum 24. As the string take-up assembly 20 rotates and translates in the direction to take up the take-up string 28, the take-up string is gradually wound onto the narrower portion of the take-up drum 24.

  Referring to FIGS. 8A and 8B, the window covering lifting operation is shown. When the shade member 38 is fully extended as shown in FIG. 8A, the pull string 28 is fully withdrawn from the thicker portion of the take-up drum 24. When the bottom rung 40 is raised by the elastic force of the spring units 14 and 16, as shown in FIG. 8b, the rotating string due to the threaded engagement between the threaded tubular member 32 and the roller 66. The winding assembly 20 moves laterally within the upper rung 12 so that the lifting string is wound along the winding drum 24 towards the narrow end of the winding drum 24.

  Since the shade member 38 is folded and stacked on the bottom rung 40 by raising the bottom rung 40, the total weight to be lifted by the elastic force applied by the spring units 14 and 16 increases. Next, the load applied to the spring unit will be described with reference to one spring unit. The load applied to the spring unit 14 is approximated by the product between the suspension weight W (including the weight of the bottom crossbar and the shade member 38 stacked on the bottom crosspiece) and the winding radius R of the winding drum 24. Is derived from the momentum M by an appropriate magnification. As the bottom rung 40 rises, W increases while the take-up cord 28 gradually slides with less friction thanks to the adapter 60 and the threaded tubular member 32 and the adapter 60. R is reduced because it is wound around the narrower portion of the wire. Therefore, despite the increase in the suspension weight W, the load M applied to one spring unit 14 can be kept at an almost unchanged level, which is overcome by the constant load spring 46 (FIG. 2) and The shade member 38 can be kept at a level at which it can be completely pulled up. To lower the window covering, the user applies a certain appropriate pulling force regardless of the height position of the window covering. Thus, the string take-up assemblies 20 and 22 allow the constant force spring units 14 and 16 to be used appropriately to lift the suspension weight burden W that increases as they rise.

  In some embodiments, such as the illustrated embodiment, the shade member itself can have an effect on the overall downward force or hanging weight. For example, if the shade member is a cellular window covering, the overall downward force can be reduced by the inherent upward spring bias on the material. The overall contribution of this spring bias varies with the extent of the cellular window covering.

  As described above, as the window covering opens, the total suspended weight increases and the overall lifting force decreases. Accordingly, the window cover ascends at a slower rate as it approaches a fully open state. Thus, the disadvantages typically found in roll shades where the shade is drawn rapidly and wildly are avoided.

  Referring again to FIG. 6, a clutch member 36 is provided to lock the shade member 38 and bottom rung 40 in the desired position. The clutch member 36 is mounted coaxially to the drive shaft 18 and releases the drive shaft 18 when the user pulls the bottom rung 40 downward to spread the shade member 38 so that the user has the desired height at the bottom rung 40. The drive shaft 18 is configured to be locked when released. When the user pulls the bottom rung down slightly again, the clutch is disengaged and the bottom rung 40 can be raised by the spring units 14 and 16. Referring to FIGS. 9A and 9B, the clutch member 36 includes a casing 70 having fixed protrusions 72 and 74. A collar 76 that rotates together with the drive shaft 18 is provided and reciprocates along the drive shaft 18 in the axial direction. A reciprocating body 78 is mounted coaxially over the collar 76, and is rotatable and axially movable with respect to the collar 76. A spring 80 having a first end 82 and a second end 84 is provided between the collar 76 and the reciprocating body 78.

  9A and 9B show the clutch when the window covering 10 is in a fully raised position. The spring 80 is in a relaxed state, and the second end 84 is brought into contact with the protrusion 74. As shown in FIGS. 10A and 10B, when the user pulls the bottom rung (not shown), a clockwise rotation (as shown) occurs in the shaft 18 and collar 76, and the second spring 80 The end 84 is separated from the protrusion 74. The spring 80 is tightened to the collar 76, so that the rotation of the collar 76 is transmitted to the reciprocating body 78 by contact between the first end 82 of the spring 80 and the reciprocating body 78. Abut. When the reciprocating body 78 comes into contact with the protrusion 72, the spring 80 is loosened again, and the drive shaft 18 can continue to rotate when the user pulls the bottom rung further. Referring to FIGS. 11A and 11B, when the user releases the bottom rung at the desired height, the spring 80 is tightened to the collar 76 and the drive shaft 18 biased by the spring units 14 and 16 (FIG. 1) is The reciprocating body 78 is rotated counterclockwise until the protrusion 72 reaches a locking position where it comes into contact with the stopper 79 of the reciprocating body 78. In this locked position, the spring 80 is tightened to stop the rotation of the drive shaft 18 against the pulling force provided by the spring units 14 and 16. Referring to FIGS. 12A and 12B, when the user pulls the bottom rung down slightly, the spring 80 is tightened and the resulting rotation of the drive shaft 18 and collar 76 causes the reciprocating body 78 to be in the locked position. To the release position. When the user releases the bottom rung, as shown in FIGS. 13A and 13B, the spring units 14 and 16 cause the drive shaft 18 to rotate counterclockwise and the second end 84 of the spring 80 to engage the protrusion 74. The spring 80 is loosened, so that the drive shaft 18 can continue to rotate and fully open the window covering.

  Another embodiment of a window covering according to the present invention is shown in FIG. In most aspects, this embodiment is the same as the previously described embodiment. The window covering 510 includes an upper cross 512 having a pair of spring units 514 and 516 with a drive shaft 518. A string take-up assembly 520 and 522 is also provided. Lift strings 528 and 530 pass through the shade member 538 and are connected to the bottom rung 540. Furthermore, at least one deceleration member 550 is provided. A deceleration member 550 can engage one string take-up assembly 522 to decelerate the rise of the bottom rung 540 as it approaches the top rung.

  A preferred embodiment of the deceleration member 520 is shown in FIGS. In the position of FIG. 15A, the string take-up assembly 522 is separated from the deceleration member 550. The string take-up assembly 522 also moves in the direction of the deceleration member 550 as the string 526 is taken up. When the string take-up assembly 522 contacts the plate 552 of the speed reduction member 550 as shown in FIG. 15B, the plate 552 is rotated by the rotation of the string take-up assembly 522. The plate 552 is connected to the shaft sleeve 554, and the shaft sleeve 554 is in contact with a speed reducing member such as viscous oil housed in the housing 556. The sleeve 554 is configured to achieve resistive contact with the deceleration member to decelerate the rotation of the string winding assembly. For example, the shaft sleeve 554 can be provided with protrusions or fins. The rate of ascending of the bottom rung by the spring units 514 and 516 is reduced as the bottom rung approaches the top rung, thus stopping more smoothly in a position where the bottom rung is fully opened.

  The above description should be understood as illustrative only and should not be understood as limiting the present invention. Still other variations can be easily made by those skilled in the art within the technical idea and scope of the present invention.

Claims (26)

A control mechanism for a self-raising window covering comprising a top rung, a suspended shade member, a bottom rung, and at least one pull-up string having a first end operatively connected to the bottom rung Because
A drive shaft;
A drive unit that is operatively connected to the drive shaft and applies a substantially constant rotational force to the drive shaft;
A first end having a first diameter attached to the drive shaft and having a diameter decreasing toward a second end having a second diameter smaller than the first diameter. A take-up string is provided for lifting a hanging weight composed of at least the bottom rung and the part of the shade member stacked on the bottom rung by a rotational force applied by the drive unit. At least one string winder assembly operable to wind the wire;
A clutch member that is operatively connected to the drive shaft, is configured to releasably engage the drive shaft, and prevent rotation of the drive shaft against a rotational force applied by the drive unit. When,
A control mechanism comprising:   The control mechanism according to claim 1, wherein the drive unit includes a constant load spring.   2. The string take-up assembly is secured to rotate relative to the drive shaft through a hub member configured to engage the string take-up assembly and the drive shaft. The control mechanism described.   4. A control mechanism according to claim 3, wherein the hub member is slidably engaged with a winding portion of the string winding assembly.   A screw that engages one or more toothed rollers so that the string winding assembly translates the string winding assembly axially along the drive shaft as the string winding assembly rotates. The control mechanism according to claim 1, comprising a cylindrical member with a mountain. The clutch member is
A reciprocating body arranged coaxially with respect to the drive shaft and movable between a release position and a locking position;
A spring member connected to the reciprocating body and operable to tighten or relieve holding of the reciprocating body on the drive shaft;
Comprising
In the locked position, the reciprocating body is configured to tighten the spring member to the drive shaft in order to prevent rotation of the drive shaft against the rotational force applied by the drive unit, and to release the release position. The control mechanism according to claim 1, wherein the spring member is relaxed with respect to the drive shaft in order to enable rotation of the drive shaft by a rotational force applied by the drive unit. .   The control mechanism according to claim 6, wherein the clutch member further includes an annular collar having an outer peripheral surface fixed to the drive shaft and to which the spring member is attached.   The control mechanism of claim 1, further comprising a speed reduction member engageable with the string take-up assembly to decelerate the upward movement of the bottom rung toward the top rung. Automatic ascending window covering,
An upper rung defining an elongated channel;
A bottom member;
A shade member suspended between the upper rung and the bottom member;
A control mechanism mounted in the channel of the upper rung;
Comprising
The control mechanism is
A drive shaft operable to rotate with a substantially constant rotational force applied by the drive unit;
A first end having a first diameter attached to the drive shaft and having a diameter decreasing toward a second end having a second diameter smaller than the first diameter. At least one string winding assembly including a winding;
A first end portion and a second end portion, the first end portion being fixed to the first end portion of the winding portion, and the second end portion being the bottom member; At least one lifting string connected to the
A clutch member operatively connected to the drive shaft and configured to releasably prevent rotation of the drive shaft;
Including window coverings.   The window covering according to claim 9, wherein the drive unit includes a constant load spring.   The window covering according to claim 9, wherein the string winding assembly is attached to the drive shaft by a hub member.   The window covering of claim 11, wherein the hub member is slidably engaged with a winding portion of the string winding assembly.   A thread that engages one or more toothed rollers so that the string winding assembly translates the string winding assembly axially along the drive shaft as the string winding assembly rotates. The window covering of Claim 9 containing a cylindrical member with attachment. The clutch member is
A reciprocating body arranged coaxially with respect to the drive shaft and movable between a release position and a locking position;
A spring member connected to the reciprocating body and operable to tighten or relieve holding of the reciprocating body on the drive shaft;
Comprising
In the locked position, the reciprocating body tightens the spring member to the drive shaft in order to prevent rotation of the drive shaft against the rotational force applied by the drive unit, and the release position. The window covering according to claim 9, wherein the spring member is configured to be relaxed with respect to the drive shaft in order to enable rotation of the drive shaft by a rotational force applied by the drive unit. .   The window covering according to claim 14, wherein the clutch member further includes an annular collar having an outer peripheral surface fixed to the drive shaft and to which the spring member is attached.   The window covering of claim 9, wherein the control mechanism further comprises a deceleration member engageable with the string winding assembly to decelerate the upward movement of the bottom member toward the upper rung.   The window covering of claim 9, wherein the shade member comprises a foldable cellular shade. Automatic ascending window covering,
The upper rung,
A plurality of lifting strings suspended from the upper rung,
A bottom member suspended from the upper rung by the lifting string;
A shade member suspended between the upper rung and the bottom member;
A clutch member operably connected to the drive shaft and configured to releasably lock the drive shaft;
Comprising
The upper rung further comprises a control mechanism comprising a drive unit configured to apply a substantially constant rotational force to the drive shaft and a string take-up assembly coaxially attached to the drive shaft;
The string winding assembly is configured to convert the rotational force of the drive unit into a linear lifting force of the lifting string and to increase the lifting force as the bottom member ascends;
A window covering in which the linear lifting force is sufficient to fully lift the bottom rung and shade member when moving the window covering from the closed position to the open position.   19. The string take-up assembly includes a take-up drum having a tapered portion and a positioning member configured to move the string take-up assembly laterally along the drive shaft during rotation. Window covering.   19. The string take-up assembly is secured to rotate relative to the drive shaft by a hub member configured to engage the string take-up assembly and the drive shaft. Window covering.   21. The window covering according to claim 20, wherein the hub member is slidably engaged with the tapered portion of the string.   The window covering according to claim 19, wherein the positioning member is a threaded cylindrical member.   The window covering according to claim 18, wherein the drive unit comprises a constant load spring. A spring member configured to releasably fix the position of the drive shaft when the clutch member is in a tightened state and to allow rotation of the drive shaft when in a relaxed state; And
The clutch member further includes a reciprocating body disposed annularly around the drive shaft and configured to selectively hold the spring member in the clamped and related positions. The window covering described.   The window covering according to claim 24, further comprising an annular collar fixed to the drive shaft and connected to the spring member.   The window covering of claim 18, further comprising a speed reducing member engageable with the string take-up assembly and in a coaxial relationship.

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