Patent Description:
Some window shades may use an operating cord for raising a bottom part of the window shade and a wand for lowering the bottom part. More specifically, the operating cord may be pulled downward to drive a rotary part in rotation, which can be transmitted to a drive axle so that the drive axle can rotate for winding a suspension cord connected with the bottom part. When a user rotates the wand, an arrester coupled to the wand can release the drive axle, which can accordingly rotate as the bottom part lowers under gravity action. Documents <CIT>, <CIT> and <CIT> respectively describe mechanisms for raising or lowering window shades.

In the aforementioned type of window shades, the braking force of the arrester may create resistance against the rotation of the drive axle when the rotary part and the drive axle rotate for raising the bottom part. As a result, the pulling force applied by the user has to overcome the braking force to be able to raise the bottom part, which may require increased effort from the user.

The present application describes a window shade and an actuating system for use with the window shade that can reduce internal friction so that component wear can be reduced and the actuating system can be operated with reduced effort. The actuating system for a window shade according to the invention is defined in independent claim <NUM>. Preferable features thereof are defined in dependent claims <NUM>-<NUM>. Window shades make use of such an actuating system are defined in claims <NUM> and <NUM>.

According to an embodiment, an actuating system for a window shade includes an axle coupling part rotatable for raising and lowering a movable rail of a window shade, a braking part and a brake coupling part connected with each other, the braking part being adapted to apply a braking force on the brake coupling part for preventing rotation of the brake coupling part, a lift actuating module including a spool connected with an operating part, the spool being rotatable in a winding direction to wind the operating part and in an unwinding direction to unwind the operating part, and a clutching mechanism including two clutching parts movable relative to the brake coupling part and the spool to selectively couple the axle coupling part to either one of the spool and the brake coupling part. The spool and the axle coupling part are concurrently rotatable relative to the brake coupling part when the axle coupling part is decoupled from the brake coupling part and coupled to the spool, and the braking force of the braking part is adapted to prevent a rotation of the axle coupling part when the axle coupling part is coupled to the brake coupling part and decoupled from the spool.

Moreover, the application describes embodiments of window shades that can incorporate the actuating system.

<FIG> and <FIG> are perspective views illustrating an embodiment of a window shade <NUM> in different states. Referring to <FIG> and <FIG>, the window shade <NUM> can include a head rail <NUM>, a movable rail <NUM>, a shading structure <NUM> and an actuating system <NUM>. The window shade <NUM> is shown in a retracted or raised state in <FIG>, and in an expanded or lowered state in <FIG>.

The head rail <NUM> may be affixed at a top of a window frame, and can have any desirable shapes. According to an example of construction, the head rail <NUM> can have an elongate shape including a cavity for at least partially receiving the actuating system <NUM> of the window shade <NUM>.

The movable rail <NUM> can be suspended from the head rail <NUM> with a plurality of suspension elements <NUM> (shown with phantom lines in <FIG>). According to an example of construction, the movable rail <NUM> may be an elongate rail having a channel adapted to receive to the attachment of the shading structure <NUM>. Examples of the suspension elements <NUM> may include, without limitation, cords, strips, bands, and the like. According to an example, the movable rail <NUM> may be a bottom rail of the window shade <NUM>. However, it will be appreciated that other shade elements may be provided below the movable rail <NUM> as needed.

The shading structure <NUM> may have any suitable structure that can be expanded and collapsed between the head rail <NUM> and the movable rail <NUM>. According to an example of construction, the shading structure <NUM> can have a cellular structure, which may include, without limitation, honeycomb structures. During use, the shading structure <NUM> can be suspended from the head rail <NUM>, and can be expanded or collapsed by displacing the movable rail <NUM> away from or toward the head rail <NUM>.

Referring to <FIG> and <FIG>, the movable rail <NUM> can move vertically relative to the head rail <NUM> for setting the window shade <NUM> to a desirable configuration. For example, the movable rail <NUM> may be raised toward the head rail <NUM> to collapse the shading structure <NUM> as shown in <FIG>, or lowered away from the head rail <NUM> to expand the shading structure <NUM> as shown in <FIG>. The vertical position of the movable rail <NUM> relative to the head rail <NUM> may be controlled with the actuating system <NUM>.

Referring to <FIG> and <FIG>, the actuating system <NUM> is assembled with the head rail <NUM>, and is operable to displace the movable rail <NUM> relative to the head rail <NUM> for adjustment. The actuating system <NUM> can include a transmission axle <NUM>, a plurality of winding units <NUM> rotationally coupled to the transmission axle <NUM>, and a control module <NUM> coupled to the transmission axle <NUM>.

The transmission axle <NUM> and the winding units <NUM> can be assembled with the head rail <NUM>. The transmission axle <NUM> is respectively coupled to the winding units <NUM>, and can rotate about a longitudinal axis <NUM>. Each of the winding units <NUM> is respectively connected with the movable rail <NUM> via at least one suspension element <NUM>, and is operable to wind the suspension element <NUM> for raising the movable rail <NUM> and to unwind the suspension element <NUM> for lowering the movable rail <NUM>. For example, the winding unit <NUM> may include a rotary drum (not shown) that is rotationally coupled to the transmission axle <NUM> and is connected with one end of the suspension element <NUM>, and another end of the suspension element <NUM> can be connected with the movable rail <NUM>, whereby the rotary drum can rotate along with the transmission axle <NUM> to wind or unwind the suspension element <NUM>. Since the winding units <NUM> are commonly coupled to the transmission axle <NUM>, the winding units <NUM> can operate in a concurrent manner for winding and unwinding the suspension elements <NUM>.

The control module <NUM> is coupled to the transmission axle <NUM>, and is operable to cause the transmission axle <NUM> to rotate in either direction about the longitudinal axis <NUM> for raising or lowering the movable rail <NUM>. In conjunction with <FIG> and <FIG>, <FIG> is an exploded view illustrating a construction of the control module <NUM>, and <FIG> is a cross-sectional view of the control module <NUM>.

Referring to <FIG>, the control module <NUM> can include a housing <NUM> that can be affixed to the head rail <NUM>. The housing <NUM> can have a cavity 210A adapted to receive at least some component parts of the control module <NUM>. According to an example of construction, the housing <NUM> may include two casing portions 212A and 212B that are attached to each other to define at least partially the cavity 210A, and a cover 212C and a bracket 212D that may be affixed to the casing portion 212A to close the cavity 210A at one side thereof. <FIG> is a perspective view illustrating the control module <NUM> without a portion of the housing <NUM> to better show inner construction details of the control module <NUM>.

Referring to <FIG>, the control module <NUM> can include an axle coupling part <NUM>, a braking part <NUM>, a brake coupling part <NUM>, a lift actuating module <NUM> and a clutching mechanism <NUM>, all of which can be assembled with the housing <NUM>. For facilitating the assembly of the different component parts, the housing <NUM> can include a fixed shaft <NUM> having multiple sections of different sizes. According to an example of construction, the fixed shaft <NUM> can include a lug <NUM> fixedly connected with the bracket 212D, and a shaft portion <NUM> fixedly attached to the lug <NUM>. The lug <NUM> and the shaft portion <NUM> can be substantially coaxial to the longitudinal axis <NUM>. It will be appreciated that the lug <NUM> and the shaft portion <NUM> may also be provided as a single part, which can be attached to or formed integrally with the bracket 212D.

The axle coupling part <NUM> can be received at least partially inside the cavity 210A of the housing <NUM>, and can extend outward through the casing portion 212B. According to an example of construction, the axle coupling part <NUM> may be provided as a unitary part of an elongate shape. The axle coupling part <NUM> may be pivotally connected about the fixed shaft <NUM> with the shaft portion <NUM> thereof inserted into a hole <NUM> provided in the axle coupling part <NUM>.

The axle coupling part <NUM> is rotationally coupled to the transmission axle <NUM> so that the transmission axle <NUM> and the axle coupling part <NUM> can rotate in unison about the longitudinal axis <NUM> relative to the housing <NUM>. For example, an end of the transmission axle <NUM> can be inserted into the hole <NUM> at a side of the axle coupling part <NUM> opposite to the fixed shaft <NUM>. A fastener (not shown) may be used to securely attach the transmission axle <NUM> to the axle coupling part <NUM>. Accordingly, the axle coupling part <NUM> can be rotationally coupled to the winding units <NUM> via the transmission axle <NUM>, and the transmission axle <NUM> and the axle coupling part <NUM> can rotate in unison about the longitudinal axis <NUM> for raising and lowering the movable rail <NUM>.

The braking part <NUM> is adapted to apply a braking force for preventing rotation of the brake coupling part <NUM>. According to an example of construction, the braking part <NUM> and the brake coupling part <NUM> are disposed around the longitudinal axis <NUM> and are connected with each other. For example, the brake coupling part <NUM> can have a hollow interior <NUM> and can be disposed around an intermediate portion of the axle coupling part <NUM>, which passes through the hollow interior <NUM> leaving a gap between the intermediate portion of the axle coupling part <NUM> and the brake coupling part <NUM>. During operation, the axle coupling part <NUM> thus can rotate relative to the brake coupling part <NUM>.

The braking part <NUM> can be disposed around the brake coupling part <NUM> in contact with an outer surface <NUM> thereof, and can apply a braking force on the brake coupling part <NUM> for preventing rotation of the brake coupling part <NUM> about the longitudinal axis <NUM>. For example, the outer surface <NUM> may be defined on a ring portion of the brake coupling part <NUM>, and the braking part <NUM> can include a wrap spring mounted around the ring portion of the brake coupling part <NUM> in frictional contact with the outer surface <NUM>. The braking part <NUM> can apply a braking force on the brake coupling part <NUM> via the frictional contact between the braking part <NUM> and the outer surface <NUM> of the brake coupling part <NUM>.

Referring to <FIG>, the lift actuating module <NUM> can include a spool <NUM> connected with an operating part <NUM>, and a spring <NUM> connected with the spool <NUM>. The operating part <NUM> can be a flexible element of a linear shape, and can have an end anchored to the spool <NUM>. Examples of the operating part <NUM> can include, without limitation, a cord or a tape. The spool <NUM> is pivotally connected with the housing <NUM>, and is rotatable in a winding direction to wind the operating part <NUM> and in an unwinding direction to unwind the operating part <NUM>. According to an example of construction, the spool <NUM> may be pivotally connected around the fixed shaft <NUM>, whereby the spool <NUM> can rotate about the longitudinal axis <NUM> for winding and unwinding the operating part <NUM>.

The spring <NUM> is connected with the spool <NUM>, and is adapted to bias the spool <NUM> to rotate in the winding direction. According to an example of construction, the spool <NUM> can have a cavity <NUM> through which passes the fixed shaft <NUM>, and the spring <NUM> can be disposed around the fixed shaft <NUM> inside the cavity <NUM> with two ends of the spring <NUM> being respectively connected with the fixed shaft <NUM> (e.g., at the lug <NUM>) and the spool <NUM>. The lift actuating module <NUM> may be operable to raise the movable rail <NUM> by pulling the operating part <NUM> so that the spool <NUM> rotates in the unwinding direction. When the operating part <NUM> is released, the spring <NUM> can urge the spool <NUM> to rotate for winding at least partially the operating part <NUM>.

The clutching mechanism <NUM> is configured to selectively couple the axle coupling part <NUM> to either one of the lift actuating module <NUM> and the brake coupling part <NUM>, wherein the clutching mechanism <NUM> is operable to couple the axle coupling part <NUM> to the spool <NUM> of the lift actuating module <NUM> and decouple the axle coupling part <NUM> from the brake coupling part <NUM> in response to a rotation of the spool <NUM> in the unwinding direction, and decouple the axle coupling part <NUM> from the spool <NUM> and couple the axle coupling part <NUM> to the brake coupling part <NUM> when the spool <NUM> rotates in the winding direction. Accordingly, the axle coupling part <NUM> and the spool <NUM> can concurrently rotate relative to the brake coupling part <NUM> free of the braking force applied by the braking part <NUM>, when the spool <NUM> rotates in the unwinding direction. This may facilitate raising of the movable rail <NUM> and reduce friction between component parts. When the spool <NUM> rotates in the winding direction, the braking force of the braking part <NUM> can be exerted through the brake coupling part <NUM> and the clutching mechanism <NUM> to the axle coupling part <NUM>, and thus is adapted to prevent a rotation of the axle coupling part <NUM>. The movable rail <NUM> can be thereby held at a desired position relative to the head rail <NUM>. As described hereinafter, the clutching mechanism <NUM> can include two clutching parts <NUM> and <NUM> that are movable relative to the brake coupling part <NUM> and the spool <NUM> to selectively couple the axle coupling part <NUM> to either one of the spool <NUM> and the brake coupling part <NUM>.

In conjunction with <FIG>, <FIG> is an exploded view illustrating some construction details of the clutching mechanism <NUM>. Referring to <FIG>, the brake coupling part <NUM> and the clutching part <NUM> can be disposed around an intermediate portion <NUM> of the axle coupling part <NUM>, and the other clutching part <NUM> can be disposed adjacent to an end <NUM> of the axle coupling part <NUM>. The clutching part <NUM> can be coupled to the brake coupling part <NUM>, and is movable relative to the axle coupling part <NUM> and the brake coupling part <NUM> between a disengaged position where the clutching part <NUM> is disengaged from the axle coupling part <NUM> and an engaged position where the clutching part <NUM> is engaged with the axle coupling part <NUM>. The clutching part <NUM> can be coupled to the spool <NUM>, and is movable relative to the axle coupling part <NUM> and the spool <NUM> between a disengaged position where the clutching part <NUM> is disengaged from the axle coupling part <NUM> and an engaged position where the clutching part <NUM> is engaged with the axle coupling part <NUM>.

The controlled movements of the two clutching parts <NUM> and <NUM> allow to switch the coupling state of the axle coupling part <NUM> with respect to the brake coupling part <NUM> and the spool <NUM> of the lift actuating module <NUM>. More specifically, the clutching mechanism <NUM> is configured so that a rotation of the spool <NUM> in the unwinding direction causes the clutching part <NUM> to move to the engaged position and causes the clutching part <NUM> to move to the disengaged position, whereby the spool <NUM>, the axle coupling part <NUM> and the clutching part <NUM> are concurrently rotatable relative to the brake coupling part <NUM>. Moreover, the clutching mechanism <NUM> is configured so that a rotation of the spool <NUM> in the winding direction causes the clutching part <NUM> to move to the disengaged position, and the clutching part <NUM> can be switched to the engaged position while the clutching part <NUM> is disengaged from the axle coupling part <NUM> so that the braking force of the braking part <NUM> is adapted to prevent a rotation of the axle coupling part <NUM>.

Each of the clutching parts <NUM> and <NUM> may be a single movable part. According to an example of construction, the two clutching parts <NUM> and <NUM> are configured to slide along the longitudinal axis <NUM> in opposite directions to selectively couple the axle coupling part <NUM> to either one of the spool <NUM> and the brake coupling part <NUM>. For example, the clutching part <NUM> can have a ring shape, and the intermediate portion <NUM> of the axle coupling part <NUM> can be disposed through the clutching part <NUM> so that the clutching part <NUM> can slide along the intermediate portion <NUM> relative to the axle coupling part <NUM>. The clutching part <NUM> can likewise have a ring shape, and can be disposed to slide along the shaft portion <NUM> of the fixed shape <NUM>.

Referring to <FIG>, the clutching part <NUM> is coupled to the brake coupling part <NUM>, and is movable between the disengaged position and the engaged position in sliding contact with the brake coupling part <NUM>. According to an example of construction, the clutching part <NUM> can be disposed around the intermediate portion <NUM> of the axle coupling part <NUM> and at least partially received in the hollow interior <NUM> of the brake coupling part <NUM>. The connection between the brake coupling part <NUM> and the clutching part <NUM> allows a limited displacement of the clutching part <NUM> relative to the brake coupling part <NUM> between the disengaged position and the engaged position. To this end, the clutching part <NUM> can be in sliding contact with the brake coupling part <NUM> inside the hollow interior <NUM> via at least one ramp surface provided on the clutching part <NUM> or the brake coupling part <NUM>. For example, the clutching part <NUM> can have a notch <NUM> disposed eccentric from the longitudinal axis <NUM>, and an inner wall <NUM> of the brake coupling part <NUM> at least partially delimiting the hollow interior <NUM> thereof can have a protrusion <NUM> that is restricted to slide within the notch <NUM>. The notch <NUM> of the clutching part <NUM> can include a ramp surface <NUM> extending between two stop surfaces 260A and 260B, the protrusion <NUM> of the brake coupling part <NUM> can have a ramp surface <NUM> extending between two stop surfaces 264A and 264B, and the clutching part <NUM> can be disposed with the ramp surface <NUM> in sliding contact with the ramp surface <NUM>.

With the aforementioned construction, the clutching part <NUM> can move relative to the brake coupling part <NUM> between the disengaged position and the engaged position with the ramp surface <NUM> in sliding contact with the ramp surface <NUM>. More specifically, the clutching part <NUM> can concurrently rotate about and slide along the longitudinal axis <NUM> for switching between the disengaged position and the engaged position, the protrusion <NUM> of the brake coupling part <NUM> being displaced between the two stop surfaces 260A and 260B of the notch <NUM> during the movement of the clutching part <NUM> relative to the brake coupling part <NUM>. When the clutching part <NUM> is in the disengaged position, the axle coupling part <NUM> is rotatable about the longitudinal axis <NUM> while the brake coupling part <NUM> and the clutching part <NUM> remain generally stationary. When the clutching part <NUM> is in the engaged position, the axle coupling part <NUM> and the clutching part <NUM> can be rotationally coupled to each other, and the braking force applied by the braking part <NUM> on the brake coupling part <NUM> is adapted to prevent a rotation of the axle coupling part <NUM> and the clutching part <NUM> via a contact between the stop surface 260A of the clutching part <NUM> and the stop surface 264A of the brake coupling part <NUM>.

Referring to <FIG>, the axle coupling part <NUM> can include a plurality of teeth <NUM> disposed around the longitudinal axis <NUM>, and the clutching part <NUM> can include a plurality of teeth <NUM> disposed around the longitudinal axis <NUM>. The teeth <NUM> can be engaged with the teeth <NUM> when the clutching part <NUM> is in the engaged position, and disengaged from the teeth <NUM> when the clutching part <NUM> is in the disengaged position. The teeth <NUM> may be disposed along a first circumference of the axle coupling part <NUM> at an end of its intermediate portion <NUM>, and the teeth <NUM> may disposed along a circular edge of the clutching part <NUM> that extends around the intermediate portion <NUM> facing the teeth <NUM> of the axle coupling part <NUM>. The teeth <NUM> and <NUM> may have a saw-tooth pattern. When the clutching part <NUM> is in the engaged position, the engagement between the teeth <NUM> and <NUM> allows torque transmission from the axle coupling part <NUM> to the clutching part <NUM> in only one direction R1 and allows rotation of the axle coupling part <NUM> relative to the clutching part <NUM> in a direction R2 opposite to the direction R1. The direction R1 corresponds to a direction of rotation that would move the stop surface 260A of the clutching part <NUM> toward the stop surface 264A of the brake coupling part <NUM>. A torque in the direction R1 can be created by the suspended load of the movable rail <NUM>. When the clutching part <NUM> is in the engaged position, the braking force of the braking part <NUM> can oppose a torque in the direction R1 to hold the movable rail <NUM> in position. When the axle coupling part <NUM> rotates in the direction R2, the configuration of the teeth <NUM> and <NUM> is so that the axle coupling part <NUM> can push the clutching part <NUM> to move away from the engaged position to the disengaged position.

Referring to <FIG>, the clutching part <NUM> is coupled to the spool <NUM> of the lift actuating module <NUM>, and is movable between the disengaged position and the engaged position in sliding contact with the spool <NUM>. According to an example of construction, the clutching part <NUM> can be disposed around the shaft portion <NUM> and at least partially received in a hollow interior of the spool <NUM>. The clutching part <NUM> can be coupled to the spool <NUM> via a sliding connection configured so that a rotation of the spool <NUM> in the unwinding direction (i.e., for unwinding the operating part <NUM>) causes the clutching part <NUM> to slide toward the axle coupling part <NUM> to the engaged position, and a rotation of the spool <NUM> in the winding direction (i.e., for winding the operating part <NUM>) causes the clutching part <NUM> to slide away from the axle coupling part <NUM> to the disengaged position. The sliding connection between the spool <NUM> and the clutching part <NUM> can be carried out via at least one ramp surface provided on the clutching part <NUM> or the spool <NUM>.

<FIG> and <FIG> are partial cross-sectional views illustrating an example of a sliding connection between the spool <NUM> and the clutching part <NUM>. Referring to <FIG>, the clutching part <NUM> can have a ramp surface <NUM> radially distant from the longitudinal axis <NUM>, and the spool <NUM> can have a protrusion <NUM> in sliding contact with the ramp surface <NUM>. The ramp surface <NUM> may be exemplary defined on an edge of a slot 270A provided on a circumferential surface of the clutching part <NUM>, and the protrusion <NUM> may be provided on an inner wall of the spool <NUM>. It will be appreciated the sliding connection may also be achieved by providing the ramp surface <NUM> on the spool <NUM> and the protrusion <NUM> on the clutching part <NUM>. Through the sliding connection, the clutching part <NUM> can concurrently rotate about and slide along the longitudinal axis <NUM> for switching between the disengaged position and the engaged position in response to a rotation of the spool <NUM>. The clutching part <NUM> is shown in the disengaged position in <FIG> and in the engaged position in <FIG>.

As shown in <FIG> and <FIG>, the clutching part <NUM> may connect with a torsion spring <NUM> that is disposed tightly around the shaft portion <NUM>. The torsion spring <NUM> can provide some resistance for assisting in keeping the clutching part <NUM> in the disengaged position.

Referring to <FIG>, the axle coupling part <NUM> can include a plurality of teeth <NUM> disposed around the longitudinal axis <NUM> axially spaced apart from the teeth <NUM>, and the clutching part <NUM> can include a plurality of teeth <NUM> disposed around the longitudinal axis <NUM>. The teeth <NUM> can be engaged with the teeth <NUM> when the clutching part <NUM> is in the engaged position, and disengaged from the teeth <NUM> when the clutching part <NUM> is in the disengaged position. The teeth <NUM> may be disposed along a second circumference of the axle coupling part <NUM> at another end of its intermediate portion <NUM> that is smaller than the first circumference along which are disposed the teeth <NUM>. The teeth <NUM> and <NUM> may have a saw-tooth pattern. When the clutching part <NUM> is in the engaged position, the engagement between the teeth <NUM> and <NUM> allows torque transmission from the spool <NUM> and the clutching part <NUM> to the axle coupling part <NUM> in only the direction R2 and allows rotation of the spool <NUM> and the clutching part <NUM> relative to the axle coupling part <NUM> in the direction R1.

Exemplary operation of the clutching mechanism <NUM> is described hereinafter with reference to <FIG>. Supposing that the clutching part <NUM> is in the engaged position and the clutching part <NUM> in the disengaged position, which corresponds to a state of the clutching mechanism <NUM> in which the axle coupling part <NUM> is coupled to the brake coupling part <NUM> and decoupled from the spool <NUM>. By pulling the operating part <NUM>, the spool <NUM> can be rotated in the unwinding direction corresponding to the direction R2, which causes the clutching part <NUM> to slide in a direction D1 from the disengaged position to the engaged position so that the axle coupling part <NUM> is rotationally coupled to the spool <NUM> via the clutching part <NUM> for rotation in the direction R2. Owing to the configuration of the teeth <NUM> and <NUM>, the coupled rotation of the spool <NUM> and the axle coupling part <NUM> in the direction R2 then can urge the clutching part <NUM> to slide in a direction D2 opposite to the direction D1 from the engaged position to the disengaged position, whereby the axle coupling part <NUM> can be decoupled from the brake coupling part <NUM>. Accordingly, the clutching mechanism <NUM> can be switched to a state in which the axle coupling part <NUM> is decoupled from the brake coupling part <NUM> and coupled to the spool <NUM> for rotation in the direction R2. In this state, the braking force of the braking part <NUM> no longer applies on the axle coupling part <NUM>, while the brake coupling part <NUM> and the clutching part <NUM> remain generally stationary, the spool <NUM>, the clutching part <NUM> and the axle coupling part <NUM> can rotate concurrently for raising the movable rail <NUM>.

When the operating part <NUM> is released after it has been extended from the spool <NUM>, the spring <NUM> can bias the spool <NUM> to rotate in the winding direction corresponding to the direction R1 for retracting the operating part <NUM>. The rotation of the spool <NUM> in the direction R1 causes the clutching part <NUM> to slide in the direction D2 from the engaged position to the disengaged position so that the axle coupling part <NUM> is rotationally decoupled from the spool <NUM>. The suspended load of the movable rail <NUM> then may cause the axle coupling part <NUM> to rotate in the direction R1. Owing to the sliding contact between the ramp surface <NUM> of the clutching part <NUM> and the ramp surface <NUM> of the brake coupling part <NUM> and a frictional contact between the axle coupling part <NUM> and the clutching part <NUM>, the rotational displacement of the axle coupling part <NUM> in the direction R1 causes the clutching part <NUM> to rotate and slide in the direction D1 from the disengaged position to the engaged position so that the axle coupling part <NUM> is coupled to the brake coupling part <NUM> via the clutching part <NUM>. As a result, the clutching mechanism <NUM> can be switched to a state in which the axle coupling part <NUM> is coupled to the brake coupling part <NUM> and decoupled from the spool <NUM>. In this state, the braking force of the braking part <NUM> can apply on the axle coupling part <NUM> to prevent its rotation in the direction R1, whereby the movable rail <NUM> can be held in position relative to the head rail <NUM> while the spool <NUM> rotates in the direction R1 for winding the operating part <NUM>.

In the clutching mechanism <NUM> described herein, the clutching part <NUM> thus can slide in the direction D1 and the clutching part <NUM> in the opposite direction D2 to rotationally couple the axle coupling part <NUM> to the brake coupling part <NUM> and at the same time rotationally decouple the axle coupling part <NUM> with respect to the spool <NUM>. Conversely, the clutching part <NUM> can slide in the direction D2 and the clutching part <NUM> in the opposite direction D1 to rotationally couple the axle coupling part <NUM> to the spool <NUM> and at the same time rotationally decouple the axle coupling part <NUM> with respect to the brake coupling part <NUM>. Since the axle coupling part <NUM> is coupled to only one of the brake coupling part <NUM> and the spool <NUM> at a time, undesirable friction between the axle coupling part <NUM> and the brake coupling part <NUM> can be prevented when the axle coupling part <NUM> rotates along with the spool <NUM>.

Referring to <FIG> and <FIG>, the control module <NUM> can further include a brake release part <NUM> connected with the braking part <NUM>, and a control wand <NUM> connected with the brake release part <NUM> via a transmission assembly <NUM>. The braking part <NUM> can be mounted in frictional contact with the outer surface <NUM> of the brake coupling part <NUM> as described previously, and can have two ends 216A and 216B respectively anchored to the housing <NUM> and the brake release part <NUM>. The brake release part <NUM> is configured to be movable for causing the braking part <NUM> to loosen its frictional contact with the brake coupling part <NUM>. According to an example of construction, the brake release part <NUM> can be disposed for rotation about the longitudinal axis <NUM>. For example, the brake release part <NUM> can have a ring shape pivotally disposed around the intermediate portion <NUM> of the axle coupling part <NUM>. The brake release part <NUM> is thereby rotatable relative to the axle coupling part <NUM> to displace the end 216B of the braking part <NUM> in a direction that urges the braking part <NUM> to enlarge and loosen its frictional contact with the brake coupling part <NUM>.

The control wand <NUM> is operable to urge the brake release part <NUM> to move for causing the braking part <NUM> to loosen the frictional contact with the brake coupling part <NUM>. The control wand <NUM> may have any suitable shape for facilitating manual operation. For example, the control wand <NUM> may have an elongate shape that extends along a lengthwise axis Y and is exposed for operation. The operating part <NUM> may be threaded through a hollow interior of the control wand <NUM>, and may have an end anchored to a handle <NUM>. The handle <NUM> is disposed adjacent to a distal end of the control wand <NUM>, and can be pulled away from the control wand <NUM> for extending the operating part <NUM> from the spool <NUM>. A guide element <NUM> may be provided inside the housing <NUM> for guiding the operating part <NUM>.

The transmission assembly <NUM> is configured so that a predetermined actuating movement of the control wand <NUM> can be transmitted through the transmission assembly <NUM> to urge the brake release part <NUM> to move for causing the braking part <NUM> to loosen the frictional contact with the brake coupling part <NUM>. In conjunction with <FIG>, <FIG> is a schematic view illustrating some construction details of the transmission assembly <NUM>. Referring to <FIG> and <FIG>, the transmission assembly <NUM> can have a construction that is adapted to the actuating movement of the control wand <NUM>. According to an example of construction, the control wand <NUM> is rotatable about the lengthwise axis Y thereof for causing the braking part <NUM> to loosen the frictional contact with the brake coupling part <NUM>, and the transmission assembly <NUM> may include two transmission elements <NUM> and <NUM>. The transmission elements <NUM> and <NUM> can include gear elements. The transmission element <NUM> has a gear portion 288A and is pivotally connected with the control wand <NUM>. The transmission element <NUM> has two gear portions 290A and 290B and is pivotally assembled inside the housing <NUM>. The gear portion 288A of the transmission element <NUM> is meshed with the gear portion 290A of the transmission element <NUM>, and the gear portion 290B of the transmission element <NUM> is meshed with a gear portion 280A provided on the brake release part <NUM>. The two transmission elements <NUM> and <NUM> may be disposed so as to respectively rotate about two axes that are perpendicular to each other, the axis of rotation of the transmission element <NUM> being parallel to the longitudinal axis <NUM>, and the axis of rotation of the transmission element <NUM> being tilted an angle relative to a vertical direction. With this arrangement, a rotational displacement of the control wand <NUM> about the lengthwise axis Y can be transmitted through the transmission assembly <NUM> to the brake release part <NUM>, which causes the brake release part <NUM> to rotate and urge the braking part <NUM> to loosen the frictional contact with the brake coupling part <NUM>. When the control wand <NUM> is released, the braking part <NUM> can recover the tightening state with respect to the brake coupling part <NUM>.

Referring to <FIG>, <FIG> and <FIG>, the control module <NUM> may include a biasing mechanism configured to assist the control wand <NUM> in recovering an initial position corresponding to the tightening state of the braking part <NUM> with respect to the brake coupling part <NUM>. For example, one of the transmission elements <NUM> and <NUM> may be coupled to a biasing spring that exerts a spring force for assisting the control wand <NUM> to recover its initial position when the control wand <NUM> is not operated by a user. According to an example of construction, the transmission element <NUM> may have a toothed portion 288B meshed with a rack element <NUM>, and the rack element <NUM> can be connected with a biasing spring <NUM>. When no external force is applied on the control wand <NUM>, the biasing spring <NUM> can urge the rack element <NUM> to slide and cause the transmission element <NUM> to rotate, which in turn can cause the control wand <NUM> to recover its initial position and the braking part <NUM> to recover the tightening state.

In conjunction with <FIG>, <FIG> and <FIG> are schematic views illustrating exemplary operation for expanding the window shade <NUM> provided with the actuating system <NUM> described previously. Referring to <FIG>, supposing that the movable rail <NUM> is initially held in position relative to the head rail <NUM>. In this initial state, the axle coupling part <NUM> is decoupled from the spool <NUM> and coupled to the brake coupling part <NUM> via the clutching part <NUM>. Accordingly, the tightening action exerted by the braking part <NUM> on the brake coupling part <NUM> can prevent rotation of the axle coupling part <NUM> in a direction that would lower the movable rail <NUM>.

Referring to <FIG> and <FIG>, a user can rotate the control wand <NUM> about its lengthwise axis Y in one direction X1 for expanding the window shade <NUM>. As described previously, this rotational displacement of the control wand <NUM> can urge the brake release part <NUM> to move for causing the braking part <NUM> to loosen the frictional contact with the brake coupling part <NUM>. As a result, the axle coupling part <NUM>, the brake coupling part <NUM>, and the clutching part <NUM> in the engaged position can rotate concurrently for lowering the movable rail <NUM> by gravity action. The spool <NUM> and the clutching part <NUM> can remain generally stationary while the axle coupling part <NUM> rotates for lowering the movable rail <NUM>.

Referring to <FIG> and <FIG>, when the movable rail <NUM> moving downward reaches a desired position, the user can release the control wand <NUM>, which can reversely rotate about its lengthwise axis Y in a direction X2 to recover its initial position owing to the action of the biasing spring <NUM>. As a result, the braking part <NUM> can recover the tightening state, and the movable rail <NUM> can be held in the desired position relative to the head rail <NUM>.

In conjunction with <FIG>, <FIG> and <FIG> are schematic views illustrating exemplary operation for raising the movable rail <NUM> of the window shade <NUM> provided with the actuating system <NUM> described previously. Referring to <FIG> and <FIG>, when a user wants to raise the movable rail <NUM>, the operating part <NUM> can be pulled downward with the handle <NUM>, which causes the spool <NUM> to rotate in the unwinding direction. As a result, the clutching mechanism <NUM> is switched to the state in which the axle coupling part <NUM> is decoupled from the brake coupling part <NUM> and coupled to the spool <NUM> via the clutching part <NUM> like previously described. Accordingly, the axle coupling part <NUM> and the spool <NUM> can rotate concurrently for raising the movable rail <NUM>.

Referring to <FIG> and <FIG>, the user can release the handle <NUM> when the movable rail <NUM> has reached a desired position or when the operating part <NUM> has extended a maximum length. As a result, the spool <NUM> rotates for winding the operating part <NUM> owing to the action of the spring <NUM>, and the clutching mechanism <NUM> is switched to the state in which the axle coupling part <NUM> is decoupled from the spool <NUM> and coupled to the brake coupling part <NUM> via the clutching part <NUM> like previously described. Accordingly, the tightening action exerted by the braking part <NUM> on the brake coupling part <NUM> can prevent rotation of the axle coupling part <NUM> so that the movable rail <NUM> is held in position while the spool <NUM> rotates in the winding direction.

The aforementioned actuation and release of the operating part <NUM> can be repeated multiple times until the movable rail <NUM> rises to a desired position.

<FIG> is an exploded view illustrating a variant construction of the control module <NUM> in which the transmission assembly <NUM> previously described is replaced with a transmission assembly <NUM>, and <FIG> is an enlarged view illustrating some construction details of the transmission assembly <NUM>. Referring to <FIG> and <FIG>, the transmission assembly <NUM> is adapted to operate with a sliding movement of the control wand <NUM> for urging the brake release part <NUM> to move for causing the braking part <NUM> to loosen the frictional contact with the brake coupling part <NUM>. Rather than rotating the control wand <NUM> about its lengthwise axis Y, the control wand <NUM> thus can be pulled downward for lowering the movable rail <NUM>.

Referring to <FIG> and <FIG>, the control wand <NUM> can be slidably connected with the housing <NUM> via a slider <NUM>. For example, the slider <NUM> can be pivotally connected with an upper end of the control wand <NUM>, and can have a rod portion <NUM> slidably received in a channel <NUM> provided inside the housing <NUM>. The pivotal connection between the control wand <NUM> and the slider <NUM> allows tilting of the control wand <NUM> relative to the slider <NUM> for facilitating operation of the control wand <NUM>. The control wand <NUM> and the slider <NUM> can slide in unison upward and downward relative to the housing <NUM>.

The transmission assembly <NUM> can include three transmission elements <NUM>, <NUM> and <NUM>. The transmission element <NUM> is movable upward and downward along with the control wand <NUM>, and can have a toothed portion <NUM>. According to an example of construction, the transmission element <NUM> can be connected with the slider <NUM>, and can slide upward and downward along with the control wand <NUM> and the slider <NUM>. The toothed portion <NUM> of the transmission element <NUM> may extend generally parallel to an axis of sliding movement of the slider <NUM>.

The transmission elements <NUM> and <NUM> may be two gear elements that are pivotally assembled inside the housing <NUM>. The transmission element <NUM> can have a gear portion 312A, and the transmission element <NUM> can have two gear portions 314A and 314B spaced apart from each other. The gear portion 312A of the transmission element <NUM> can be respectively meshed with the toothed portion <NUM> of the transmission element <NUM> and the gear portion 314A of the transmission element <NUM>. The gear portion 314B of the transmission element <NUM> can be meshed with the gear portion 280A of the brake release part <NUM>. With this arrangement, a downward sliding displacement of the control wand <NUM> can be transmitted through the transmission assembly <NUM> to the brake release part <NUM>, which causes the brake release part <NUM> to rotate and urge the braking part <NUM> to loosen the frictional contact with the brake coupling part <NUM>. When the control wand <NUM> is released, the braking part <NUM> can recover the tightening state with respect to the brake coupling part <NUM>.

Referring to <FIG>, the transmission element <NUM> can be coupled to a biasing spring <NUM> that exerts a spring force for assisting the control wand <NUM> to recover its initial position when the control wand <NUM> is not operated by a user. According to an example of construction, the transmission element <NUM> can be fixedly connected with a rod <NUM>, and the biasing spring <NUM> can be disposed around the rod <NUM> with two ends of the biasing spring <NUM> respectively connected with the transmission element <NUM> and a shoulder portion <NUM> provided on a sidewall <NUM> of the housing <NUM>. When no external force is applied on the control wand <NUM>, the biasing spring <NUM> can urge the transmission element <NUM> and the slider <NUM> to slide upward, which in turn can cause the control wand <NUM> to slide upward to recover its initial position and the braking part <NUM> to recover the tightening state.

Aside the transmission assembly <NUM>, the remaining components of the control module <NUM> shown in <FIG> can be similar to the previous embodiment shown in <FIG>.

In conjunction with <FIG> and <FIG>, <FIG> and <FIG> are schematic views illustrating exemplary operation for expanding the window shade <NUM> provided with the control module <NUM> shown in <FIG>. Referring to <FIG>, a user can pull the control wand <NUM> downward in a direction V1 for expanding the window shade <NUM>. As described previously, this downward sliding displacement of the control wand <NUM> can urge the brake release part <NUM> to move for causing the braking part <NUM> to loosen the frictional contact with the brake coupling part <NUM>. As a result, the axle coupling part <NUM>, the brake coupling part <NUM>, and the clutching part <NUM> coupled thereto can rotate concurrently for lowering the movable rail <NUM> by gravity action. The spool <NUM> and the clutching part <NUM> can remain generally stationary while the axle coupling part <NUM> rotates for lowering the movable rail <NUM>. When the movable rail <NUM> moving downward reaches a desired position, the user can release the control wand <NUM>, which can slide upward in a direction V2 to recover its initial position owing to the action of the biasing spring <NUM>. As a result, the braking part <NUM> can recover the tightening state, and the movable rail <NUM> can be held in the desired position relative to the head rail <NUM>. For retracting the window shade <NUM> shown in <FIG> and <FIG>, the movable rail <NUM> can be raised by pulling and releasing the handle <NUM> like previously described.

In conjunction with <FIG>, <FIG> is a perspective view illustrating another variant construction of the actuating system <NUM> that further includes a shade tilting mechanism <NUM>, <FIG> is a perspective view illustrating a portion of the shade tilting mechanism <NUM>, and <FIG> is an exploded view illustrating construction details of the control module <NUM> provided in the actuating system <NUM> shown in <FIG>. Referring to <FIG>, the shade tilting mechanism <NUM> is operable to adjust an angular position of a shading structure of a window shade, and can include a ladder assembly <NUM> and a rotary wheel <NUM> connected with each other. The ladder assembly <NUM> can loop about the rotary wheel <NUM>, and can include two strip portions 332A and 332B that extend downward from the rotary wheel <NUM> and are respectively connected with the shading structure of the window shade. The two strip portions 332A and 332B can include, without limitation, cord, tapes, and the like. The rotary wheel <NUM> can rotate to vertically displace the two strip portions 332A and 332B in opposite directions. According to an example of construction, the rotary wheel <NUM> can be pivotally supported about the transmission axle <NUM>. The rotary wheel <NUM> can be mounted so as to be rotatable relative to the transmission axle <NUM> for vertically displacing the two strip portions 332A and 332B in opposite directions.

Referring to <FIG>, the control wand <NUM> can be connected with the brake release part <NUM> via the transmission assembly <NUM> like described previously, and can be connected with the shade tilting mechanism <NUM> via another transmission assembly <NUM>. The transmission assembly <NUM> can include a plurality of gear elements <NUM>, <NUM>, <NUM>, <NUM> and <NUM>, and a transmission axle <NUM>. The transmission axle <NUM> can extend parallel to the transmission axle <NUM>, and can be pivotally connected with the housing <NUM>. The two gear elements <NUM> and <NUM> can be rotationally coupled to the transmission axle <NUM> at two axially spaced apart locations so that the transmission axle <NUM> and the gear elements <NUM> and <NUM> can rotate in unison. The gear element <NUM> is pivotally disposed inside the housing <NUM>, is rotationally coupled to the control wand <NUM>, and is meshed with the gear element <NUM>. According to an example of construction, the gear element <NUM> can be rotationally coupled to the control wand <NUM> via the slider <NUM>. More specifically, the rod portion <NUM> of the slider <NUM> can be received through a hole 342A provided in the gear element <NUM>. The shape of the rod portion <NUM> and the shape of the hole 342A are configured so that the slider <NUM> is slidable upward and downward along with the control wand <NUM> relative to the gear element <NUM> and the housing <NUM>, and the gear element <NUM> and the slider <NUM> are rotatable along with the control wand <NUM> relative to the housing <NUM> during rotation of the control wand <NUM> about the lengthwise axis Y. The gear element <NUM> is rotationally coupled to the rotary wheel <NUM> so that both the rotary wheel <NUM> and the gear element <NUM> are rotatable in unison about a same axis. The gear element <NUM> is respectively meshed with the gear element <NUM> and the gear element <NUM>.

With the aforementioned construction, the rotary wheel <NUM> of the shade tilting mechanism <NUM> is rotatable about the transmission axle <NUM> and is connected with the control wand <NUM> via the transmission assembly <NUM>. A rotation of the control wand <NUM> about its lengthwise axis Y can urge the transmission axle <NUM> to rotate through the engagement of the gear elements <NUM> and <NUM>, which in turn causes the rotary wheel <NUM> to rotate about the transmission axle <NUM> through the engagement of the gear elements <NUM>, <NUM> and <NUM> for displacing the two strip portions 332A and 332B in opposite directions. Accordingly, the control wand <NUM> is rotatable about its lengthwise axis Y to actuate the shade tilting mechanism <NUM>, and is slidable vertically to urge the brake release part <NUM> to move for causing the braking part <NUM> to loosen the frictional contact with the brake coupling part <NUM> as described previously.

Based on the aforementioned description, it will be appreciated that multiple shade tilting mechanisms <NUM> of the same construction may be provided for use in a window shade. Each shade tilting mechanism <NUM> can likewise have the rotary wheel <NUM> pivotally supported about the transmission axle <NUM>, and a corresponding set of gears including the gear elements <NUM>, <NUM> and <NUM> can be likewise disposed for connecting each shade tiling mechanism <NUM> with the control wand <NUM>.

Aside the shade tilting mechanism <NUM> and the transmission assembly <NUM>, the other components of the actuating system <NUM> shown in <FIG> can be similar to the embodiments previously described. In particular, the control module <NUM> of the actuating system <NUM> shown in <FIG> can be similar to the control module <NUM> shown in <FIG>.

<FIG> is a perspective view illustrating an embodiment of the window shade <NUM> incorporating the actuating system <NUM> shown in <FIG>, and <FIG> are schematic views illustrating exemplary operation of the window shade <NUM> shown in <FIG>. Referring to <FIG>, the window shade <NUM> can include the head rail <NUM>, the movable rail <NUM>, and the shading structure <NUM> disposed between the head rail <NUM> and the movable rail <NUM>. Like previously described, the winding units <NUM> that are assembled with the head rail <NUM> are connected with the movable rail <NUM> via the suspension elements <NUM>, whereby the movable rail <NUM> can be suspended from the head rail <NUM>. The shading structure <NUM> can include a plurality of slats <NUM> that are suspended from the head rail <NUM> with the ladder assembly <NUM> of the shade tilting mechanism <NUM>. More specifically, each of the slats <NUM> can be respectively connected with the two strip portions 332A and 332B of the ladder assembly <NUM>, which respectively extend at a front and a rear of the slats <NUM>. Accordingly, the shade tilting mechanism <NUM> is operable to adjust an angular position of the slats <NUM>.

Referring to <FIG>, a user can pull the control wand <NUM> downward in a direction V1 for expanding the window shade <NUM>. As described previously, this downward sliding displacement of the control wand <NUM> can urge the brake release part <NUM> to move for causing the braking part <NUM> to loosen the frictional contact with the brake coupling part <NUM>. As a result, the axle coupling part <NUM>, the brake coupling part <NUM>, and the clutching part <NUM> coupled thereto can rotate concurrently for lowering the movable rail <NUM> by gravity action. The spool <NUM> and the clutching part <NUM> can remain generally stationary while the axle coupling part <NUM> rotates for lowering the movable rail <NUM>. When the movable rail <NUM> moving downward reaches a desired position, the user can release the control wand <NUM>, which can slide upward in a direction V2 to recover its initial position owing to the action of the biasing spring <NUM>. As a result, the braking part <NUM> can recover the tightening state, and the movable rail <NUM> can be held in the desired position relative to the head rail <NUM>.

Referring to <FIG>, <FIG> and <FIG>, for adjusting an angular position of the slats <NUM>, a user can rotate the control wand <NUM> about its lengthwise axis Y, which can be transmitted through the transmission assembly <NUM> to actuate the shade tilting mechanism <NUM>. For example, the control wand <NUM> can be rotated in a direction S1 for tilting the slats <NUM> toward one side (shown in <FIG>), and can be rotated in an opposite direction S2 for tilting the slats <NUM> toward another opposite side (shown in <FIG>).

Referring to <FIG>, <FIG> and <FIG>, for retracting the window shade <NUM>, the movable rail <NUM> can be raised by pulling and releasing the handle <NUM> like previously described.

Advantages of the structures described herein include the ability to provide an actuating system operable to lower and raise a movable rail of a window shade with reduced effort. The actuating system includes a clutching mechanism that can reduce internal friction during operation, whereby component wear can be reduced, service life can be expanded, and operation of the actuating system can be facilitated. Moreover, the actuating system is adaptable for use with different types of window shades, which can simplify the manufacture of window shades.

Claim 1:
An actuating system (<NUM>) for a window shade (<NUM>), comprising:
an axle coupling part (<NUM>) rotatable for raising and lowering a movable rail (<NUM>) of a window shade (<NUM>);
a braking part (<NUM>) and a brake coupling part (<NUM>) connected with each other; and
a lift actuating module (<NUM>) including a spool (<NUM>) connected with an operating part (<NUM>), the spool (<NUM>) being rotatable in a winding direction to wind the operating part (<NUM>) and in an unwinding direction to unwind the operating part (<NUM>);
characterized in that:
the braking part (<NUM>) is adapted to apply a braking force on the brake coupling part (<NUM>) for preventing rotation of the brake coupling part (<NUM>); and
the actuating system (<NUM>) comprises a clutching mechanism (<NUM>) including two clutching parts (<NUM>, <NUM>) movable relative to the brake coupling part (<NUM>) and the spool (<NUM>) to selectively couple the axle coupling part (<NUM>) to either one of the spool (<NUM>) and the brake coupling part (<NUM>), wherein the spool (<NUM>) and the axle coupling part (<NUM>) are concurrently rotatable relative to the brake coupling part (<NUM>) when the axle coupling part (<NUM>) is decoupled from the brake coupling part (<NUM>) and coupled to the spool (<NUM>), and the braking force of the braking part (<NUM>) is adapted to prevent a rotation of the axle coupling part (<NUM>) when the axle coupling part (<NUM>) is coupled to the brake coupling part (<NUM>) and decoupled from the spool (<NUM>).