Control module having a clutch for raising and lowering a window shade

A control module may be used for raising and lowering a window shade. This configuration allows a user to pull the operating cord a predetermined distance to raise the window shade, then release the operating cord until it has retracted, and then pull the operating cord another predetermined distance to raise the window shade again. A brake mechanism is operably connected to a brake release and configured to lock or unlock the drive axle. A clutch is adapted to be mounted on the axle for selectively engaging the cord drum to the axle. The cord drum may rotate independent of the drive axle when a clutch is disengaged from the drive axle. As a result, movement of the operating cord will not cause the window shade to raise while the clutch is disengaged. When the clutch is engaged with the drive axle, the cord drum and adapter sleeve may rotate together to drive the rotation of the drive axle for raising the window shade.

FIELD OF INVENTION

The present invention generally relates to a window shade utilizing a control module adapted for connection to a drive axle of a window shade for raising or lowering of the window shade.

BACKGROUND OF INVENTION

There are numerous types of window shades and window coverings. Examples of such include Venetian blinds, Roman shades, and cellular shades. Window shades may be lowered to cover windows and minimize sunlight exposure to a room or area while increasing privacy and preventing others from viewing through the window. Window shades may be raised to provide a full and clear view through the window or permit sunlight to pass. Typically, a window shade may be raised or lowered by manipulating an operating cord. The user may pull the operating cord in a downward direction to raise the window shade and release the operating cord to lower the window shade.

In typical fashion, the operating cord is attached to a drive axle within the window shade assembly and used to raise or lower the window shade. Pulling the operating cord in a downward direction causes the drive axle to rotate and wind support cords to raise the window shade while releasing the operating cord causes the drive axle to rotate in an opposite direction therefore lowering the window shade. Because of the amount of window shade to be raised, the range of movement of the operating cord can be quite long, and the length of the cord itself when the window shade is raised is also long.

In addition to the generally undesired aesthetic appearance of long operating cords, operating cords may cause a significant threat to various users and in particular to young children. There is a possibility that young children may asphyxiate if an operating cord becomes tangled around their neck. For this reason, it is important to maintain an operating cord at a high location outside the reach of young children. This may be difficult to do when dealing with certain types of windows and window shades. Generally, while window shades are at a closed position, the operating cord is at a high location. When the user pulls down on the operating cord to open the window shade, the operating cord may move to a lower position where it may dangle at a dangerously low position. This low location creates a danger for young children.

Oftentimes, it may be difficult for users to manipulate long operating cords of this nature. A user may use arm movements to pull the operating cord downward. At a certain point, however, the user's arm is fully extended and the user can no longer pull the cord downward. This requires that the user must release and re-grip the operating cord at a higher location and continue pulling the operating cord downward to take the window shade to a desired height. This procedure may be tedious and unduly cumbersome.

SUMMARY OF THE INVENTION

The present invention relates to a novel control mechanism for raising and lowering a window shade that allows for operation of the window shade with a shorter length of operating cord. The control mechanism is biased toward a locked position for maintaining a desired state of opening of the window shade. The control mechanism is switchable to an unlocked position by pulling action on an operating cord or control stick, and enables one to lower the bottom rail of the window shade.

A window shade assembly may have a window shade that may be raised or lowered by pulling on an operating cord. A user may lower the window shade by gently pulling the operating cord in a downward direction. The user may raise the window shade by continuously pulling the operating cord in a downward direction.

The window shade may be raised by a process of pulling and releasing the operating cord. This process may be similar to a ratcheting technique. The user may pull the operating cord to raise the window shade, then allow the operating cord to retract, and then pull the operating cord again to continue to raise the window shade. This process may be repeated until the window shade reaches a proper height. This configuration allows the window shade to be configured with an operating cord having a much shorter length than other window shade assemblies known in the art. The operating cord can be less than half the length of the window shade and is generally preferred to be about one third the height of the window shade meaning three pulls on the operating cord will fully raise the shade.

The window shade assembly of the present invention has a clutch, which enables a user to pull the operating cord in a downward direction and raise the window covering and then release the operating cord allowing it to retract in an upward direction. When the clutch is disengaged from the drive axle, the retraction of the operating cord will not cause the window shade to be moved. Instead, the window shade will remain in a fixed position. The user may then again continuously pull the operating cord in a downward direction to continue to raise the window shade. This process may be repeated until the window shade reaches a desired height.

While the operating cord is continuously pulled in a downward direction, a brake mechanism is moved to an unlocked position allowing rotation of the drive axle and the clutch operatively engages a cord drum assembly with the drive axle.

The operating cord is pulled and the brake mechanism is moved to an unlocked position by a brake release that moves from an initial biased locked position to a release position allowing the brake mechanism to unlock and permit rotation of the drive axle. The brake mechanism may move to an unlocked position when the brake release is moved by the downward movement of the operating cord or movement of a separately connected control stick. In one example, the brake mechanism may include a spring element, such as a torsion spring, configured to tightly clamp the adapter sleeve in its initial locked position so as to preclude the adapter sleeve from rotating thereby maintaining the drive axle in a fixed position and the window shade locked at a particular height. Once the operating cord is pulled, the brake release moves a portion of the spring element thereby loosening the grasp of the spring element around the adapter sleeve and allowing the operating sleeve to rotate.

The operating cord is pulled and the clutch engages the cord drum assembly with the drive axle. The drive axle is operatively connected to the window shade by way of a raised cord and may raise or lower the window shade by rotating in a particular direction. When the clutch is engaged, the operating cord may be used to rotate the cord drum to connect and rotate the drive axle to raise the window shade. When the clutch is disengaged, the cord drum is not connected to the drive axle and rotates independent of the drive axle. In one example, the clutch may be used to connect the cord drum assembly with an adapter sleeve secured to the drive axle. When the clutch is engaged, the cord drum assembly, the adapter sleeve, and the drive axle are configured to rotate together to raise the window shade.

In one example, the clutch may include a first coupling element and a second coupling element. The first coupling element and second coupling element may be configured to rotate together to a first position and a second position. At the first position, the outer surfaces of the first and second coupling elements may define a guide track that forms a closed-loop configuration. At the second position, the outer surfaces of the first and second coupling elements may include a guide track that forms a loop configuration having a stop region. A track member, such as a rolling ball, may be configured to move in the guide track as the first and second coupling elements rotate. The first and second coupling elements may rotate together while the rolling ball is lodged at the stop region. During this rotation, the rolling ball may contact and engage a radial groove of the adapter sleeve. This configuration allows the clutch to engage and connect the cord drum to the adapter sleeve. The first and second coupling elements and the adapter sleeve may therefore rotate together to drive the drive axle and raise the window shade.

In another example, the clutch may include a coupling element having at least one stud and a plurality of cogs configured to move in an axial direction along the drive axis. The at least one stud may be configured to engage at least one guide track located at an outer surface of the cord drum. As the cord drum rotates in a first direction, the guide track moves around the at least one stud allowing the coupling element to move in an axial direction toward the adapter sleeve. During the rotation, the at least one stud will reach an end point of the guide track and the plurality of cogs of the coupling element will engage a plurality of cogs of the adapter sleeve. It will be appreciated that the at least one stud of the coupling element and the at least one guide track may be switchable so as to allow at least one stud on the cord drum to engage at least one guide track on the cord drum. These configurations allow the clutch to engage and connect the cord drum to the adapter sleeve. The cord drum, coupling element, and the adapter sleeve may therefore rotate together to drive the drive axle and raise the window shade.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF INVENTION

The invention disclosed herein is susceptible to embodiment in many different forms. The embodiments shown in the drawings and described in detail below are only for illustrative purposes. The disclosure is intended as an exemplification of the principles and features of the invention, but does not limit the invention to the illustrated embodiments.

Referring toFIG. 1, a window shade assembly10is shown. The window shade assembly10may include a head rail12, a window shade14, a bottom rail16, a drive axle18, an operating cord20, a control module22, and suspension cords (not shown) connecting between the head rail12and the bottom rail16. The window shade14may be opened by raising the bottom rail16toward the head rail12. Raising the bottom rail16may be effected by manipulating the operating cord20, so as to wind the suspension cords connecting between the head rail12and the bottom rail16. Lowering of the bottom rail16and closing of the window shade14may be done by manipulation of the operating cord20to unwind the suspension cords, and thereby lower the bottom rail16. Using suspension cords to raise the bottom rail to raise or lower the window shade is described in U.S. Pat. No. 7,275,580 to Yu and U.S. Patent Publication No. 2008/00179017 to Yu et al. which are hereby incorporated by reference.

The window shade14may be of any type generally known in the art. In one example, the window shade14may be a cloth material such as a honeycomb material, Venetian blinds, or any other type of shade known in the art. In another example, the window shade14may include a plurality of rails or slats extending vertically and parallel to one another.

The head rail12may be of any types and shapes generally known in the art. The head rail12may be located at a top portion of the window shade assembly10and configured to mount the drive axle18and control module22. The bottom rail16may be of any type generally known in the art and located at a bottom portion of the window shade assembly10. The bottom rail16may be raised by the operating cord20and the suspension cords (not shown) to move the window shade14in an upward direction.

The drive axle18may define a drive axis and be operatively connected to the bottom rail16such that rotation of the drive axle18will cause the bottom rail16to raise or lower. In one example, the rotation of the drive axle18causes the suspension cords to raise the bottom rail16and therefore raise the window shade14. The drive axle18may be operatively connected with the control module22and configured to raise or lower the window shade14in response to movement of the operating cord20.

Referring toFIGS. 1-25, the window shade assembly10may permit a user to raise and lower the window shade14by pulling on the operating cord20. The user may lower the window shade14by gently pulling the operating cord20in a downward direction. The user may then release the operating cord20, which will shift in an upward direction. The upward shift of the operating cord20, however, will not cause the window shade14to be raised or lowered. Instead, the window shade14will remain at a fixed and locked height. The user may continuously pull the operating cord20in a downward direction to continue to raise the window shade14.

In one example, a window shade assembly10may have a relatively shorter operating cord20that allows the user to raise the window shade by repeatedly pulling the operating cord20and then releasing the operating cord20. The operating cord20can be less than one half the height of the window shade. When the operating cord is one third the height of the window shade, the window shade is raised in three pulls of the cord. This process is similar to a ratcheting technique allowing the user to pull the operating cord20to raise the window shade14a certain amount, then allow the operating cord20to retract, and then pull the operating cord20again to continue to raise the window shade. This process may be repeated until the window shade14reaches a desired height. This configuration allows the operating cord to be a much shorter length than those traditionally used in the art.

One example of a control module22that enables the described operation is shown inFIGS. 2 and 3. The control module22includes a brake mechanism24, a brake release26, a cord drum28, and a clutch30. The control module22preferably also includes a motor mechanism32such as a spring motor for driving the cord drum28. The motor mechanism32, however, may also be disposed at a location external of the control module22. The control module22may also include a housing34, a support panel36, and a lid panel38configured to enclose the different elements of the control module22.

The clutch30is adapted to selectively couple and uncouple movements of the cord drum28with the drive axle18. When the clutch30is in an uncoupled state, relative movements between the drive axle18and the cord drum28are permitted, e.g., the drive axle18driven by the weight of the bottom rail16and window shade14can rotate independent from the cord drum28kept stationary for lowering the window shade14and bottom rail16, or the cord drum14can rotate to wind the operating cord10while the drive axle18is locked in a stationary position. When the clutch30is in a coupled state, rotation of the cord drum28can be transmitted to the drive axle18via the clutch30for raising the window shade14and bottom rail16.

In this embodiment, the clutch30may be located between the brake mechanism24and the cord drum28, and may include a first coupling element40, a second coupling element42, a spring element44, mounting fixtures46and48, and a rolling member50such as a rolling ball. In some examples, the clutch30may also include an adapter sleeve76.

Referring toFIGS. 3-5, the mounting fixtures46and48can be affixed at spaced-apart positions on a stationary rod49extending from the lid panel38along the axis of the drive axle18. The first coupling element40may be pivotally assembled around at least one portion of the mounting fixture48, and the second coupling element42may be pivotally assembled around at least one portion of the other mounting fixture46, such that the first coupling element40and second coupling element42can rotate around the axis of the drive axle18in either directions for turning the clutch30to either of the coupled state and uncoupled state.

Referring toFIG. 4, the first coupling element40may be generally cylindrical and configured to mate with the second coupling element42. More specifically, the first coupling element40preferably comprises a cylindrical outer surface66that extends between two end portions of the first coupling element40. The outer surface66includes a recessed region that extends around the first coupling element40so as to define at least partially a guide track64of the clutch30, and at least one notch65. In one example, two notches65can be provided approximately diametrically opposite from each other. A first end portion of the first coupling element40proximate to the cord drum28includes two opposite radial flanges52with which the cord drum28can engage for driving rotational movements of the first coupling element40in either direction. A second end portion of the first coupling element40proximate to the second coupling element42has at least one radial abutment54disposed at a position proximate to the notch65(FIG. 14). Two radial abutments54are preferably formed on an outer surface of the first coupling element40at approximately diametrically opposite positions, and proximate to each corresponding notch65. The first coupling element40also includes at least one groove56that is angularly spaced apart from the radial abutment54. Preferably two grooves56are formed on an outer surface of the first coupling element40at approximately diametrically opposite positions, each groove56being in proximity of one corresponding radial abutment54.

Referring toFIG. 5, the second coupling element42may be generally cylindrical and configured to mate with the first coupling element40. The second coupling element42preferably has two approximately diametrically opposite radial ribs58each having an outer surface68, and an extension60that extends from each radial rib58along a radial direction towards the center of the second coupling element42.

As shown inFIG. 21, when the first and second coupling elements40and42are assembled with each other, a closed-loop guide track64that runs along the circumference of the first and second coupling elements40and42is formed between the outer surfaces66and68of the first and second coupling elements40and42. Each of the radial ribs58can then be movably received at least partially in one corresponding notch65of the first coupling element40, and the extension60can be movably inserted through a corresponding groove56for guiding the relative movement between the first and second coupling elements40and42. The radial ribs58can thereby slide in the notches65to form or remove stop regions61(as better shown inFIG. 17) in the guide track64.

Referring toFIGS. 6-8, the adapter sleeve76is preferably generally cylindrical and is affixed on the drive axle18such that both the adapter sleeve76and the drive axle18rotate in unison. The adapter sleeve76includes a central hole77, and a radial groove78formed on an inner surface of the central hole77and extending linearly parallel with the axis of the drive axle18. Once the clutch30is assembled, the first and second coupling elements40and42are positioned through the central hole77of the adapter sleeve76, such that the guide track64at least partially overlaps with the length of the radial groove78in the adapter sleeve76, the rolling member50being movably engaged into the guide track64and radial groove78.

When the clutch30is in the uncoupled state, the relative position between the first and second coupling elements40and42is such that the rolling member50can move along the radial groove78and the guide track64around the circumference of the first and second coupling elements40and42as the drive axle18and adapter sleeve76rotate, independent from the cord drum28. When the clutch30is in the coupled state, the second coupling element42is angularly shifted to a second position relative to the first coupling element40so as to form a recessed stop region61in the guide track64at a position shifted radially from the notch65(as shown inFIG. 17). As a result, movement of the rolling member50along the guide track64and radial groove78can be blocked at the stop region61, such that rotational movement from the cord drum28can be transmitted through the first and second coupling elements40and42to the adapter sleeve76and drive axle18. Still, in another example, the clutch30may be adapted to transmit rotational movement from the cord drum28directly to the drive axle18.

Referring toFIGS. 11 and 12, the cord drum28can be generally cylindrical and pivotally assembled around the stationary rod49, at a position adjacent to one side of the first coupling element40that is opposite the side of the second coupling element42. The cord drum28is connected with the operating cord20, and is operable to rotate for winding the operating cord20around the cord drum28. The cord drum28also includes at least one radial flange62at one end portion proximate to the first coupling element40that can engage with the radial flange52of the first coupling element40for driving rotating movements of the clutch30.

Referring toFIGS. 2,11and12, the cord drum28is coupled with the motor mechanism32, which is configured to drive rotation of the cord drum28in a direction to wind the operating cord20thereon. The motor mechanism32can be a torsion spring that is assembled through an inner cavity of the cord drum28, the torsion spring having a first end affixed on the stationary rod49and a second end affixed with the cord drum28. Alternatively, the motor mechanism32may be located externally of the control module22and used to drive the reverse rotation of the cord drum28. In this example, the motor mechanism32may be a motor device separate from the control module22but still operatively connected to the cord drum22to drive the reverse rotation of the cord drum22.

Referring toFIGS. 2,3,6,9and10, the brake mechanism24is mounted around the drive axle18, and is operable to either tighten and lock the drive axle18in position, or loosen and unlock the drive axle18for allowing its rotation in either direction. In the illustrated embodiment, the brake mechanism24can include a spring element70, such as a torsion spring. The spring element70has a generally cylindrical shape, and is mounted around the adapter sleeve76. The spring element70has a first prong72and a second prong74. The first prong72extends outward from the spring element70and is anchored with the housing34, whereas the second prong74extends outward from the spring element70and is anchored with the brake release26operable by a user.

Referring toFIGS. 9 and 10, the brake release26can be operable to lock and unlock the brake mechanism24. In one embodiment, the brake release26can include a generally cylindrical collar portion82, and a release actuator crank80connected with the collar portion82at an eccentric position and securely joined with the second prong74of the spring element70. The collar portion82can be mounted coaxial to the drive axis of the drive axle18, but is independent from the movement of the drive axle18. In the illustrated embodiment, the collar portion82is pivotally assembled around a portion of the first coupling element40, with the release actuator crank80extending generally parallel to the drive axis of the drive axle18. When the brake release26is in the locked position, the release actuator crank80is located at a relatively higher position and the spring element70of the brake mechanism24can tighten and lock the drive axle18in position. When the brake release26is pulled downward to a release position, the release actuator crank80is shifted to a relatively lower position, which also pulls the second prong74in a direction to loosen the spring element70and unlock the drive axle18, thereby allowing the drive axle18to rotate.

A bore84may also be provided at an end portion of the release actuator crank80and configured to receive a release mechanism for actuating the brake release26. At least a portion of the operating cord20may movably pass through the bore84and a stop plug86fixedly attached on the operating cord20may engage with the bore84. While the stop plug86is engaged with the bore84, a user may gently pull the operating cord20to move the brake release26to the release position to unlock the drive axle18and allow its rotation.

While the operating cord20is not being manipulated by the user, the window shade14is locked in a fixed position. In this position, the spring element70of the brake mechanism24tightens on the adapter sleeve76, which blocks rotation of the drive axle18. Alternatively, the adapter sleeve76may be removed and the spring element70may tighten directly around the drive axle18to block the rotation.

As shown inFIG. 13, when the user wants to lower the bottom rail16, the operating cord20can be gently pulled downward to move the brake release26to the release position and cause the spring element70to loosen. The brake release26may be moved to the release position by biasing the release actuator crank80to a down position. In the illustrated example, the release actuator crank80can be moved to the down position by slightly pulling the operating cord20downward, the movement of which is transmitted to the release actuator crank80via engagement between the stop plug86and the bore84. In other embodiments, the release actuator crank80can also be moved to the down position by pulling downward a control stick87that is separate from the operating cord20and connected with the release actuator crank80. With the stop plug86remaining engaged with the bore84and the brake release26kept in the release position, the unlocked drive axle18can rotate in a direction that unwinds the suspension cords attached with the bottom rail16, driven by the weight of the bottom rail16and window shade14stacked thereon. While the drive axle18and adapter sleeve76rotate for lowering the bottom rail16, the rolling member50rolls along the radial groove78and the guide track64of the clutch30. More specifically, while the bottom rail16is lowered, the spring element44can exert resistance to keep the first and second coupling elements40and42stationary, such that the clutch30can remain in the uncoupled state without stop regions61in the guide track64. In this uncoupled state, the radial rib58of the second coupling element42is spaced apart from the radial abutment54in the notch65of the first coupling element40.

Once the bottom rail16moving downward reaches the desired height, the brake release26can be moved to the locked position as the spring element70recovers its initial state and tightens around the adapter sleeve76, thereby locking the drive axle18and adapter sleeve76in position and allowing the bottom rail16to be locked at the desired height.

Referring toFIGS. 14-17, when the user wants to raise the bottom rail16, the operating cord20can be pulled downward, causing the brake release26to move to the release position and unlock the drive axle18and adapter sleeve76. Once the brake release26is in the release position, further downward pulling of the operating cord20forces the stop plug86to dislodge from the bore84, and causes the operating cord20to unwind from the cord drum28and slide through the bore84. As shown inFIG. 14, the cord drum28rotates in a direction that unwinds the operating cord20, causing the radial flange62of the cord drum28to push against the radial flange52of the first coupling element40. The first coupling element40is thereby angularly urged to move relative to the second coupling element42, until the radial abutment54of the first coupling element40comes in contact and pushes against the radial rib58of the second coupling element42, as shown inFIG. 15. In this second position, the configuration of the guide track64is changed to form the stop region61therein, as shown inFIGS. 16 and 17.

As the operating cord20is further pulled downward, the cord drum28and clutch30rotate in unison until the rolling member50is positioned in the stop region61. In the illustrated embodiment, two stop regions61can be formed in the guide track64so as to limit the course of the rolling member50for reaching the closest stop region61. Once the rolling member50reaches the stop region61, the clutch30is turned to the coupled state. Owing to the abutment of the rolling ball50at the stop region61and in the radial groove78of the adapter sleeve76, further pulling action on the operating cord20in the same direction can cause rotation of the cord drum28, which can be transmitted from the cord drum28to the clutch30via contact between the radial flanges62and52, and from the clutch30to the drive axle18via engagement of the rolling member50between the radial groove78of the adapter sleeve76and the stop region61of the clutch30. The bottom rail16can then be raised by rotation of the cord drum28driven by pulling down the operating cord20.

The user may release the operating cord20at any particular time such as when the bottom rail16has reached a desired height or after the operating cord20has been fully extended. In response, the spring element70returns to its tightened configuration and tightly holds around the adapter sleeve76, while the release actuator crank80of the brake release26biased by the spring element70moves upward to its initial locked position. The tightened configuration of the spring element70securely locks and blocks rotation of the adapter sleeve76and drive axle18. As a result, both the adapter sleeve76and drive axle18are fixed and the window shade14is locked in position at the desired height. Meanwhile, the motor spring32drives reverse rotation of the cord drum28thereby causing the operating cord20to retract and wind about the cord drum28.

Referring toFIG. 18, as the cord drum28rotates in the reverse direction, the radial flange62of the cord drum28contacts and pushes against the diametrically opposite radial flange52of the first coupling element40for driving the first coupling element40to rotate in unison relative to the second coupling element42.

Referring toFIGS. 19-21, the rotation of the first coupling element40and the cord drum28causes the radial abutment54of the first coupling element40to move away from the radial rib58of the second coupling element42, until another abutment position is reached for recovering the configuration of the closed-loop guide track64without stop regions61shown inFIG. 21. The configuration of the closed-loop guide track64without stop regions61may be reached when the extension60abuts against an end edge56A of the groove56as shown inFIG. 4. This causes the clutch30to move to the uncoupled state while the motor mechanism32further drives reverse rotation of the cord drum28for winding the operating cord20as the first and second coupling element40and42rotate in unison. Since the stop regions61are removed from the guide track64, this coupled rotation of the first and second coupling elements40and42results in a course of the rolling member50along the guide track64and the groove78in the adapter sleeve76. Locked by the spring element70, the adapter sleeve76and drive axle18are kept stationary as the first and second coupling elements40and42and cord drum28rotate for winding the operating cord20. The bottom rail16and window shade14can be locked in position as the operating cord20is wound around the cord drum28. Once the winding is partially or entirely complete (the operating cord20can be wound around the cord drum28until the stop plug86engages with the bore84), the user may again pull the operating cord20in a downward direction to further lift the window shade14. This process may be repeated until the window shade14reaches the desired height.

In an alternate embodiment, as shown inFIGS. 22-25D, a control stick87may be additionally connected to the release actuator crank80and operable to move the brake release26from the initial locked position to the release position. As shown inFIGS. 23A-23D, the control stick87may have a generally hollow cavity such that the operating cord20passes through the hollow interior and extends a distance beyond a distal end89of the control stick87. Referring toFIGS. 23A-23C, when the user wants to lower the bottom rail16, the control stick87can be pulled downward to move the brake release26to the release position. While the control stick87is pulled downward, the distance between the distal edge89of the control stick87and the end of the operating cord20may slightly decrease. Since the control stick87is connected to the release actuator crank similar to80onFIGS. 9 and 10, the operating cord20is specifically used for raising the bottom rail16and may not necessarily need the stop plug similar to86inFIGS. 10 and 11. As shown inFIG. 23D, when pulled, the operating cord20slides downward to extend further outside the control stick87, and causes the brake release26to move to the release position by applying a downward force on the release actuator crank. As the operating cord20unwinds, the cord drum28is driven in rotation to cause the bottom rail16to raise in the same manner described previously. While the operating cord20is being pulled, the distance between the distal edge89of the control stick87and the end of the operating cord20increases.

In another alternate embodiment, as shown in FIGS.24and25A-25D, the control stick87is connected at a lower end91of the operating cord20proximate to the stop plug86. As shown inFIGS. 25A-25C, while the stop plug86is engaged with the bore84, the user can lower the bottom rail16by gently pulling down on the control stick87to move the brake release26to the release position. The user can raise the bottom rail16by continuously pulling down the control stick87. As shown inFIG. 25D, the control stick87pulls the operating cord20causing the stop plug86to dislodge from the bore84and the cord drum20to rotate for raising the bottom rail16. Although similar to the previous embodiment above having only the operating cord20, the control stick87in this embodiment is generally rigid making it easier for some users to grasp and therefore easier to lower and raise the bottom rail16.

Another preferred embodiment is shown inFIGS. 26-38. Similar to the previous embodiment ofFIGS. 1-25, the window shade assembly100may permit a user to raise and lower the window shade114by pulling on the operating cord120. The user may lower the window shade114by gently pulling the operating cord120in a downward direction. The user may raise the window shade114by continuously pulling the operating cord120in a downward direction.

Similar to above, the window shade assembly100in this embodiment includes the head rail112, the window shade114, the bottom rail116, the drive axle118, the operating cord120, the control module122, and suspension cords (not shown).

One example of the control module122that enables the described operation is discussed below and refers toFIGS. 27 and 28. The control module122includes the brake mechanism124, the brake release126, the cord drum128, and the clutch130. The control module122may also include a motor mechanism132such as the spring motor for driving the cord drum128. The motor mechanism132, however, may also be disposed at a location external of the control module122. The control module122may also include the housing134, the support panel136, and the lid panel138configured to house the different elements of the control module122.

The clutch130is adapted to selectively couple and uncouple movements of the cord drum128with the drive axle118. When the clutch118in an uncoupled state, relative movements between the drive axle118and the cord drum128are permitted, e.g., the drive axle118driven by the weight of the bottom rail116and window shade114can rotate independent from the cord drum128kept stationary for lowering the window shade114and bottom rail116, or the cord drum128can rotate to wind the operating cord120while the drive axle118is locked in a stationary position. When the clutch130is in a coupled state, rotation of the cord drum128can be transmitted to the drive axle118via the clutch130for raising the window shade114and bottom rail116.

In this embodiment, the clutch130may be located between the brake mechanism124and the brake release126and configured to selectively connect the cord drum128with the drive axle118. The clutch130may include a coupling element140and a split ring171. In some examples, the clutch may also include the adapter sleeve176.

Referring toFIGS. 29A-29C, the coupling element140has a collar portion151approximately cylindrical in shape and adapted to mount around a circumference of the cord drum128, and an opposite end portion facing the adapter sleeve176. The coupling element140is pivotally configured to rotate about the axis of the drive axle118and move in an axial direction along the axis of the drive axle118for turning the clutch130to either the coupled state or uncoupled state.

The coupling element140may be generally cylindrical and configured to mate with the adapter sleeve176and the cord drum128. More specifically, the coupling element140includes an outer surface that extends between two end portions of the coupling element140.

The collar portion151of the coupling element140has an inner surface that includes at least one radial stud152with which the cord drum128can engage for driving rotational movements of the coupling element in either direction. The radial stud52protrudes inward and inserts into an associated guide track156provided on an outer surface of the cord drum128that pivotally mounts through the collar portion151of the coupling element140. As shown inFIGS. 36A,37A and38A, the radial stud152may movably engage the guide track156such that the radial stud152can move along the guide track156as the cord drum128rotates. The guide track156may be shaped such that rotation of the cord drum128can be converted into a translation movement of the coupling element140parallel with the drive axle118via interaction between the radial stud152and guide track156. For example, as better shown inFIG. 34, the guide track156may include a first section156aof an arc-shape centered on the axis of the drive axle118, and a second section156bthat is turned toward the coupling element140and connected with an end of the first section156a. The guide track156is provided in an amount that corresponds to the amount of radial studs152on the coupling element140.

A second end portion of the coupling element140proximate to the adapter sleeve176has a plurality of cogs154disposed at the outer surface facing the adapter sleeve176. The plurality of cogs154may be configured to contact and engage a plurality of cogs178provided on one facing side of the adapter sleeve176for engaging the clutch130to the adapter sleeve176. As shown inFIGS. 36B and 37B, the coupling element140can move axially, driven by the rotation of the cord drum128and the interaction between the radial stud152and the guide track156, for causing the plurality of cogs154of the coupling element140to engage with or disengage from the plurality of cogs178of the adapter sleeve176. The clutch130is turned to the coupled state when the plurality of cogs154of the coupling element140engage with the plurality of cogs178of the adapter sleeve176, and is turned to the uncoupled state when the plurality of cogs154of the coupling element140disengage from the plurality of cogs178of the adapter sleeve176.

Referring toFIGS. 31A-31C, the adapter sleeve176is preferably generally cylindrical and is affixed around the drive axle118such that both the adapter sleeve176and the drive axle118rotate in unison. The adapter sleeve176includes a central hole177and a plurality of cogs178formed at one end of the adapter sleeve176. The plurality of cogs178of the adapter sleeve176are configured to engage with the corresponding plurality of cogs154of the coupling element140during operation. Once the clutch130is rotated to a coupled state, the coupling element140is positioned through the central hole177of the adapter sleeve176, such that the plurality of cogs154of the coupling element140mate with the plurality of cogs178of the adapter sleeve176. As shown, each of the cogs154and178can have a triangular cross-section such that they can engage with each other when the coupling element140rotates in one direction, and easily disengage from each other when the coupling element140rotates in a reverse direction.

When the clutch130is in the uncoupled state, the plurality of cogs154of the coupling element140are disengaged from the plurality of cogs178of the adapter sleeve176for permitting relative movements between the drive axle118and the cord drum128, e.g., the drive axle118and adapter sleeve176can rotate for lowering the bottom rail116independent from the cord drum128kept stationary, or the cord drum128can rotate for winding the operating cord120independent from the drive axle118locked in position. For turning the clutch130from the uncoupled state to the coupled state, the cord drum128can be rotated by pulling on the operating cord120, which causes the coupling element140to rotate and then axially shift in a direction toward the adapter sleeve176owing to the radial stud152moving into the second section156bof the guide track160. As a result, the plurality of cogs154of the coupling element140moves toward and engage the plurality of cogs178of the adapter sleeve176, thereby turning the clutch130to the coupled state. Consequently, rotational movement of the cord drum128can be transmitted through the coupling element140to the adapter sleeve176and drive axle118. Still, in another example, the adapter sleeve may be removed and the clutch130may be adapted to transmit rotational movement from the cord drum128directly to the drive axle118.

Referring toFIG. 34, the cord drum128may be generally cylindrical and pivotally assembled around the stationary rod149, at a position adjacent to one side of the coupling element140that is opposite the side of the coupling element140. The cord drum128is connected with the operating cord120and is operable to rotate for winding the operating cord120around the cord drum128. The cord drum128is also configured to engage the clutch130for connection to the drive axle118. The cord drum128preferably includes at least one guide track156that can engage the corresponding at least one stud152of the coupling element140for driving rotating and axial movements of the clutch130. Alternatively, the cord drum128will have at least three guide tracks for engaging at least three studs of the coupling element140. Still, it will be appreciated that the guide track156and stud152may be switched and the cord drum128may include at least one stud configured to engage a guide track of the coupling element.

Referring toFIGS. 27 and 28, the cord drum128is coupled with the motor mechanism132, which is configured to drive rotation of the cord drum128in a direction to wind the operating cord120thereon. The motor mechanism132can be a torsion spring that is assembled through an inner cavity of the cord drum128, the torsion spring having a first end affixed on the stationary rod149and a second end affixed with the cord drum128. Alternatively, the motor mechanism132may be located externally of the control module122and used to drive the reverse rotation of the cord drum128. In this example, the motor mechanism132may be a motor device separate from the control module122but still operatively connected to the cord drum122to drive the reverse rotation of the cord drum122.

Referring toFIGS. 27,28and30, the brake mechanism124is mounted around the drive axle118, and is operable to either tighten and lock the drive axle118in position, or loosen and unlock the drive axle118for allowing rotation in either direction. In the illustrated embodiment, the brake mechanism124may include a spring element170, such as a torsion spring. The spring element170has a generally cylindrical shape and is configured with spring-like characteristics permitting tightening or loosening depending on the circumstances. The spring element170is mounted at the drive axis and includes a first prong172and a second prong174. The first prong172extends outward from the spring element170and is anchored with the housing134, whereas the second prong174extends outward from the spring element170and is anchored with the brake release126operable by a user.

Referring toFIGS. 32 and 33, the brake release26can be operable to lock and unlock the brake mechanism124. In one embodiment, the brake release126can include a generally cylindrical collar portion182, and a release actuator crank180connected with the collar portion182at an eccentric position and securely joined with the second prong174of the spring element170. The collar portion182can be mounted coaxial to the drive axis of the drive axle118, but is independent from the movement of the drive axle118. In the illustrated embodiment, the collar portion182is exemplary assembled around a portion of the coupling element140with the release actuator crank180extending generally parallel to the drive axis of the drive axle118. When the brake release126is in the locked position, the release actuator crank80biased by the spring element170is located at a relatively higher position, and the spring element170of the brake mechanism124can tighten and lock the drive axle118in position. When the brake release126is pulled downward to a release position, the release actuator crank180is shifted to a relatively lower position, which also pulls the second prong174in a direction to loosen the spring element170and unlock the drive axle118, thereby allowing the drive axle118to rotate.

A bore184may also be provided at an end portion of the release actuator crank180and configured to receive a release mechanism for actuating the brake release126. At least a portion of the operating cord120may movably pass through the bore184and a stop plug186fixedly attached on the operating cord120may engage with the bore184. While the stop plug186is engaged with the bore184, a user may gently pull the operating cord120to move the brake release126to the release position to unlock the drive axle118.

While the operating cord120is not being manipulated by the user, the window shade114is locked in a fixed position. In this position, the spring element170of the brake mechanism tightens on the adapter sleeve176, which blocks rotation of the drive axle118. Alternatively, the adapter sleeve176may be removed and the spring element170may tighten directly around the drive axle118to block the rotation thereof.

As shown inFIG. 35, when the user wants to lower the bottom rail116, the operating cord120can be gently pulled downward to move the brake release126to the release position and cause the spring element170to loosen. The brake release126may be moved to the release position by biasing the release actuator crank180to a down position. In the illustrated example, the release actuator crank180can be moved to the down position by slightly pulling the operating cord120downward, the movement of which is transmitted to the release actuator crank180via engagement between the stop plug186and the bore184. In other embodiments, the release actuator crank180can also be moved to the down position by pulling downward a control stick87that is separate from the operating cord120and connected with the release actuator crank180. With the stop plug186remaining engaged with the bore184and the brake release126kept in the release position, the unlocked drive axle118can rotate in a direction that unwinds the suspension cords attached with the bottom rail116, driven by the weight of the bottom rail116and window shade114stacked thereon. While the drive axle118and adapter sleeve176rotate for lowering the bottom rail116, the split ring171can provide some degree of rotational resistance to the coupling element140as the split ring171tightens around the coupling element140. As a result, the coupling element140remains disengaged from the rotating adapter sleeve176, and the clutch130can be kept in the uncoupled state.

Once the bottom rail116moving downward reaches the desired height, the brake release126biased by the spring element170can be moved to the locked position, and the spring element170can recover its initial state and tighten around the adapter sleeve176, thereby locking the drive axle118and the adapter sleeve176in position and allowing the bottom rail116to be locked at the desired height.

Referring toFIGS. 36A-38B, when the user wants to raise the bottom rail116, the operating cord120can be pulled downward causing the brake release126to move to the release position and unlock the drive axle118and adapter sleeve176. Once the brake release126is in the release position, further downward pulling of the operating cord120forces the stop plug186to dislodge from the bore184, and causes the operating cord120to unwind from the cord drum128and slide through the bore184. As shown inFIG. 36A-37B, as the cord drum128rotates in a direction that unwinds the operating cord120, the radial stud152of the coupling element140shifts from a first abutment position in the first section156ato a second abutment position in the second section156bof the guide track156, causing the coupling element140to move in an axial direction toward the adapter sleeve176. Once the radial stud152has reached the second abutment position in the second section156bof the guide track156, the plurality of cogs154of the coupling element140engage the plurality of cogs178of the adapter sleeve176to turn the clutch130to the coupled state. Consequently, further rotation of the cord drum128can be transmitted from the cord drum128to the clutch130via the abutment position of the radial stud152in the guide track156, and from the clutch130to drive axle118via engagement between the plurality of cogs154of the coupling element140and the plurality of cogs178of the adapter sleeve176. The bottom rail116can be thereby raised by rotation of the cord drum128driven by pulling down the operating cord120.

The user may release the operating cord120at any particular time, such as when the bottom rail116has reached a desired height or after the operating cord120has been fully extended. In response, the spring element170returns to its tightened configuration and tightly holds around the adapter sleeve176, while the release actuator crank180of the brake release126moves upward to its initial locked position. The tightened configuration of the spring element170securely locks and blocks rotation of the adapter sleeve176and drive axle118. As a result, both the adapter sleeve176and drive axle118are fixed and the window shade114is locked in position at the desired height. Meanwhile, the motor spring132drives reverse rotation of the cord drum128thereby causing the operating cord120to retract and wind about the cord drum128. Referring toFIGS. 37A-37B, as the cord drum128rotates in a reverse direction, the radial stud152is shifted from the second abutment position in the second section156bto the first abutment position in the first section156aof the guide track156, causing the plurality of cogs154of the coupling element140to disengage from the plurality of cogs178of the adapter sleeve176. As a result, the clutch130can be turned to the uncoupled state. While the clutch130is in the uncoupled state, the motor mechanism132further drives reverse rotation of the cord drum128with the coupling element140for winding the operating cord128, independent of the adapter sleeve176locked by the spring element170. The coupling element140and the cord drum128continue to rotate together independent of the adapter sleeve176as the operating cord120is continuously wound until the stop plug186contacts and engages the bore184of the release actuator crank. Locked by the spring element170, the adapter sleeve176and drive axle118are kept stationary, as the coupling element140and the cord drum128rotate for winding the operating cord120. Since the adapter sleeve176is not engaged with the coupling element140and the cord drum128, the drive axle118does not move and the bottom rail116and window shade114can be locked in position as the operating cord120is would around the cord drum128. Once the winding is at least partially complete, the user may again pull the operating cord120in a downward direction to further lift the window shade114. This process may be repeated until the window shade114reaches the desired height.

Similar to that discussed above, additional embodiments forFIGS. 26-38may include the control stick87used to lower the bottom rail116as shown inFIGS. 22-23C. The control stick87may be connected to the release actuator crank80for releasing the brake release26and may have a generally hollow structure. As shown inFIG. 23D, the operating cord20passes through the hollow interior of the control stick87and can be pulled for raising the bottom rail116.

Similar to that discussed above, another additional embodiment forFIGS. 26-38may include the control stick87used for both lowering and raising the bottom rail116. As shown in FIGS.24and25A-25D, the control stick87may be coupled at a lower end91of the operating cord20proximate to the stop plug86. As discussed above, a user may lower the bottom rail116by gently pulling on the control stick87and may raise the bottom rail116by continuously pulling on the control stick87.

The foregoing description and the drawings are illustrative of the present invention and not to be taken as limiting. Other arrangements of the engagement structure may be implemented. Such variations and modifications are within the spirit and the scope of the present invention and will be readily apparent to those skilled in the art in view of the scope of the invention as claimed herein.