Control system for architectural coverings with reversible drive and single operating element

The present invention provides for retractable coverings for architectural openings utilizing a control system having a single operating element allowing a user to move a retractable covering between extended and retracted positions by imparting a repetitive motion to the operating element. The control system may include an input assembly, a transmission, and an output assembly cooperatively engaging to convert linear movement of the operating element into rotational movement of a head roller in the required direction to provide movement of the covering in the desired direction and distance. The input assembly may convert linear movement of the operating element into rotational movement imparted to the transmission. The input assembly may also engage the transmission to effect the direction of rotational output from the transmission. The transmission imparts rotational movement to the output assembly, which interfaces with the head roller to rotate the head roller and to provide a braking feature.

FIELD OF THE INVENTION

The present invention relates to retractable coverings for architectural openings. More particularly, the present invention relates to operating systems for controlling retractable coverings for architectural openings using a single operating element.

BACKGROUND OF THE INVENTION

Operating systems utilized in window coverings for architectural openings, such as shade and blind assemblies, are commonly used. Conventional shade and blind assemblies typically comprise a head rail, bottom rail, and slats or a covering disposed there between. Generally, a control system for raising and lowering such blinds or shades are installed in the head rail and may include an operating element, such as a cord, for lowering or raising the blinds or shades. The operating element is typically connected to pulleys or drums within the head rail, which when activated by a user, lift the bottom rail or lower the bottom rail via cords attached to the bottom rail. The operating element may be a continuous loop so as to present to the user a convenient method for operating the shade or blind. Other control systems may have a plurality of operating elements that are not in a loop so as to present the user a choice of one of the operating elements to raise or lower the blind. Other control systems, such as the cord lock system, may employ a single operating element that is not in a loop, is used to both raise and lower the blind, and is locked into place by a pivoting lock that directly engages and binds the cord (i.e., operating element).

Whether the control system utilizes a single looped type operating element or a plurality of operating elements, the operator must choose which direction to pull the loop or which operating element to activate in order to move the architectural covering in a desired direction. This can be especially confusing if the operating elements are tangled.

Inherent in the loop operating element and cord lock systems is the problem of having a very long operating element with which to operate the system. Often, a greater length of operating element is necessary to raise or lower the shade or blind due to the longer drop of the shade or blind. A greater length of the operating element or the use of a looped cord present a strangulation hazard to children who may become entangled in the operating element.

U.S. patent application Ser. No. 10/791,645, which was filed Mar. 1, 2004 and is hereby incorporated in its entirety into the present application, discloses a novel control system that addresses many of the aforementioned problems associated with window covering operating systems. However, said control system is not configured such that it is compatible with every operating system for a window covering. Also, improvements in operational smoothness and dependability would be beneficial.

There is a need in the art for a control system offering improved operational smoothness and dependability while addressing the aforementioned challenges related to moving window coverings. There is also a need in the art for a method of using and making such a control system.

BRIEF SUMMARY OF THE INVENTION

The present invention, in one embodiment, is a control system for a roller tube equipped retractable covering for architectural openings. The control system employs a single operating element (i.e., cord, cable, chain, etc.) that is retractable. To lower the covering, the operating element is repeatedly pulled/extended in a first downward direction/path, the control system automatically retracting the operating element after each pull/extension. To raise the covering, the operating element is repeatedly pulled/extended in a second downward direction/path, the control system automatically retracting the operating element after each pull/extension.

The present invention provides for retractable coverings for architectural openings utilizing a control system having a single operating element allowing a user to move a retractable covering for architectural openings between extended and retracted positions by imparting a repetitive motion to the operating element. When the retractable covering is vertically disposed, a user can raise or lower the retractable covering by imparting a repetitive up and down motion to the pull cord.

In one aspect of the present invention, a covering for an architectural opening includes a head rail assembly, at least one sheet of fabric, and a head roller rotatably supported by the head rail assembly and adapted to extend or retract the at least one sheet upon rotation of the head roller in a first direction or a second direction. A control system is connected with the head rail assembly and is adapted to rotate the head roller in the first direction and the second direction. The control system includes an input assembly, a reversible transmission, and an output assembly. The input assembly includes a single operating element and is operative to convert linear motion of the operating element into rotational motion of a first motion transfer element. The transmission is operative to translate rotation of the first motion transfer element into rotation of a second motion transfer element in either of two desired output rotational directions. The output assembly is operatively engaged with the second motion transfer element to rotate the head roller. A pull force applied in a first pull direction/path imparted on the single operating element causes the head roller to rotate in the first direction, and the pull force applied in a second pull direction/path imparted on the single operating element causes the head roller to rotate in the second direction.

In another form of the present invention, the input assembly includes a single operating element and is operative to convert linear motion of the operating element into rotational motion of a first motion transfer element. The transmission is operative to translate rotation of the first motion transfer element in the first direction into rotation of a second motion transfer element through at least one planet gear rotatably connected with a planet carrier. The output assembly is operatively engaged with the second motion transfer element to rotate the head roller. The input assembly includes a braking element adapted to brake the planet carrier to cause rotation of the second motion transfer element in the second direction, and the input assembly is adapted to release the planet carrier to cause rotation of the second motion transfer element in the first direction.

In yet another form of the present invention, the input assembly includes a single operating element and is operative to convert linear motion of the operating element into rotational motion of a first motion transfer element. The transmission is operative to translate rotation of the first motion transfer element in the first direction into rotation of a second motion transfer element though a planetary gear set configured to selectively operate in a first configuration and a second configuration. The output assembly is operatively engaged with the second motion transfer element to rotate the head roller. The first configuration provides a first mechanical advantage and causes the second motion transfer element to rotate at a first speed. The second configuration provides a second mechanical advantage and causes the second motion transfer element to rotate at a second speed.

In still another form of the present invention, the input assembly includes a single operating element and is operative to convert linear motion of the operating element into rotational motion of a first motion transfer element. The transmission is operative to translate rotation of the first motion transfer element into rotation of a second motion transfer element through a clutch and at least one third gear. The output assembly operatively engaged with the second motion transfer element to rotate the head roller. Rotation of the first motion transfer element in the first direction engages the least one third gear to activate the clutch to cause rotation of the second motion transfer element in the first direction. The clutch is configured to allow rotation of the second motion transfer element in the first direction and second direction when the clutch is deactivated.

In still another form of the present invention, the input assembly includes a single operating element and is operative to convert linear motion of the operating element into rotational motion of a first motion transfer element. The transmission operative to translate rotation of the first motion transfer element into rotation of a second motion transfer element. The output assembly is operatively engaged with the second motion transfer element to rotate the head roller. The input assembly is configured to engage the transmission to cause the head roller to rotate in the first direction when the operating element travels in a first path through the input assembly, and is configured to engage the transmission to cause the head roller to rotate in a the second direction when the operating element travels in a second path through the input assembly.

In still another form of the present invention, the input assembly includes a single operating element and is operative to convert linear motion of the operating element into rotational motion of a first motion transfer element. The transmission is operative to translate rotation of the first motion transfer element into rotation of a second motion transfer element. The output assembly operatively engaged with the second motion transfer element to rotate the head roller. A pull force applied in a first pull direction imparted on the single operating element causes the head roller to rotate in the first direction. The input assembly is operative to allow a change in direction of the pull force on the single operating element while the head roller is rotating in the first direction without reversing rotation of the head roller.

In still another form of the present invention, the input assembly is operative to convert linear motion of an operating element into rotational motion of a first motion transfer element. The transmission operative to translate rotation of the first motion transfer element into rotation of a second motion transfer element through at least a third gear rotatably connected with a planet carrier. The output assembly operatively engaged with the second motion transfer element to rotate the head roller. The input assembly includes a shift arm having a pawl adapted to engage ratchet teeth on the planet carrier when a pull force in a first pull direction is imparted on the single operating element. The input assembly is also configured to automatically retract the single operating element into the head rail assembly and disengage the pawl from the ratchet teeth when no pull force is applied to the single operating element.

The present invention, in one embodiment, is an input assembly for a control system adapted to selectively extend and retract a covering for an architectural opening. The control system has a transmission configured to receive a rotational input in a first rotational direction and selectively provide a rotational output in the first rotational direction or in a second rotational direction. The input assembly comprises an operating element, a spool, a biasing element, a pulley and a shift arm. The spool is rotatably mounted on a first axle and adapted to storably receive the operating element. The biasing element is coupled to the spool and adapted to cause the spool to retract the operating element from an extended state onto the spool. The pulley is rotatably mounted on a second axle and adapted to receive the operating element. The shift arm is pivotally mounted on a third axle and includes a pawl tooth and a first surface for engaging the operating element. The operating element extends from the spool, about the pulley and adjacent the first surface of the shift arm. Displacement of the operating element in a first direction brings the operating element into contact with the first surface and causes the shift arm to pivot such that the pawl tooth is prevented from engaging the transmission. Displacement of the operating element in a second direction allows the shift arm to pivot such that the pawl tooth engages the transmission.

In one embodiment, the shift arm further includes a second surface for engaging the operating element. Displacement of the operating element in the second direction brings the operating element into contact with the second surface and causes the shift arm to pivot such that the pawl tooth engages the transmission.

In one embodiment, pawl tooth engagement with the transmission causes the transmission to provide rotational output in the second rotational direction. Failure of the pawl tooth to engage with the transmission causes the transmission to provide rotational output in the first rotational direction.

The present invention, in one embodiment, is an input assembly for a control system adapted to selectively extend and retract a covering for an architectural opening. The input assembly includes a transmission, a pulley, a shift arm and an operating element. The transmission is rotationally mounted on a first axle and includes a spool. The pulley is rotationally mounted on a second axle. The shift arm is pivotally mounted on a third axle and includes a pawl tooth. The operating element retractably extends from the spool, about the pulley and adjacent the shift arm. Extending the operating element from the spool in an extending direction provides the transmission with a rotational input in a first rotational direction.

The present invention, in one embodiment, is a method of selectively extending and retracting a covering for an architectural opening. The method includes: a routing an operating element from a spool, about a pulley and adjacent a shift arm, wherein the spool drives a transmission rotationally mounted on a first axle, the pulley is rotationally mounted on a second axle, and the shift arm includes a pawl tooth for engaging the transmission and is privotally mounted on a third axle; and extending the operating element in an extension direction to create a rotational input for the transmission in a first rotational direction.

The features, utilities, and advantages of various embodiments of the invention will be apparent from the following more particular description of embodiments of the invention as illustrated in the accompanying drawings and defined in the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

I. Discussion of First Embodiment

a. General Overview of First Embodiment

Retractable coverings for architectural openings are well known in the art. Such retractable coverings are generally movable between extended and retracted positions. When such coverings are vertically oriented, they are moveable between raised and lowered positions. Retractable coverings may also include vanes or slats, which are typically movable or tiltable between open and closed positions. A head rail typically houses a control system to allow a user to move the retractable covering between retracted and extended positions. As such, the retractable covering may be suspended from the head rail, and may include a bottom rail with vanes or slats disposed between the head rail and the bottom rail. The control system may include an operating element, such as a pull cord, to allow a user to operate the control system. Operation of the control system causes the retractable covering to move.

The present invention provides for a control system having a single operating element allowing a user to move the retractable covering between extended and retracted positions by imparting a repetitive motion to the operating element. For example, when the retractable covering is vertically disposed, a user can raise or lower the retractable covering by imparting a repetitive up and down motion to the pull cord. While the present invention is described below in connection with a covering of the type shown inFIG. 1, it is to be appreciated that the present invention is applicable to other types of devices for covering architectural openings.

As shown inFIG. 1, the covering100includes a vertical first fabric sheet102parallel to a vertical second fabric sheet104which are interconnected by a plurality of horizontal spaced flexible fabric vanes106. The covering100shown inFIG. 1is also provided with a light control feature. The light control feature is affected through motion of the first sheet102relative to the second sheet104in a direction perpendicular to the fabric vanes106. Relative motion between the first sheet and the second sheet changes the angle of the vanes, which in turn, controls the amount of light admitted through the covering. The covering may be configured to react in different ways in response to being lowered or raised. For example, the covering100shown inFIG. 1opens (i.e. vanes are orthogonal to the first sheet and the second sheet) only when the covering is in a fully extended or lowered position, as shown inFIG. 6F. At any position, other than the fully extended position, the covering100is in a closed condition with the first fabric sheet102and the second fabric sheet104being movable vertically together and in close proximity being separated only by the vanes106which are disposed in flat substantially coplanar relationship between the sheets, as shown inFIG. 6E.

As shown inFIGS. 6E and 6F, the first fabric sheet102and the second fabric sheet104are suspended from a head roller108. As can be understood fromFIGS. 1-5A, the head roller108is connected with a control system110and rotatably supported inside a head rail assembly112. The head rail assembly112includes a left end cap114and a right end cap116connected with a front rail118. A pull cord120is provided to allow a user to operate the control system110in order to raise or lower a bottom rail122of the covering100. Operation of the control system110imparts rotational motion to the head roller108, which in turn wraps the covering100onto the head roller108or unwraps the covering from the head roller, causing the bottom rail122to move up or down, respectively. As explained in more detail below, the pull cord120is connected to an operating cord124(see inFIGS. 2 and 3) through a stopper or coupler126. Various types of stoppers or couplers126may be utilized. For example, the stopper or coupler126shown inFIGS. 2 and 3is in the form of a releasable clasp126. In another form, the stopper or coupler may be configured as a knot in the operating element. When the control system is not in use, the operating cord124is retracted inside the head rail assembly112. A tassel128may be also provided to allow a user to more easily grasp the pull cord120when operating the control system110.

c. Control System

FIGS. 2,7E, and7F illustrate how the control system110is operated to raise the covering100, andFIGS. 3,6E and6F illustrate how the control system110is operated to lower the covering100. Direction of movement of the covering, either upward or downward, is dictated by the generally downward direction in which the user pulls on the pull cord120. More particularly, the downward direction in which the user pulls on the pull cord120, which can be selectively angled, causes the control system110to engage and rotate the head roller108to either wrap or unwrap the covering100, which causes the bottom rail122to move up or down, respectively. In addition, the control system100allows a user to repeatedly pull on the pull cord120in the same downward direction to place the covering in a desired position.

In a first embodiment, as shown inFIGS. 1-3, the control system110is located on the right end cap116. However, in a second embodiment, the control system110is located on the left end cap114. The following discussion of the subject invention will be made in reference to the first embodiment depicted inFIGS. 1-3, wherein the control system110is located on the right end cap116. With respect to the second embodiment, wherein the control system110is located on the left end cap114, those skilled in the art will understand that the configuration and operation of the second embodiment is identical to those of the first embodiment, except physical orientation and operational movement of the second embodiment are the mirror image of the physical orientation and operational movement of first embodiment.

In order to raise the covering100, as shown inFIGS. 2,7E, and7F, a user grasps the pull cord120and pulls downwardly in a vertical direction with respect to the head rail assembly112. The user may also pull downwardly in a slightly right angled diagonal direction to move the covering in the upward direction. As discussed in more detail below, by pulling downwardly either vertically or in the slightly right angled diagonal direction, both referred to as an upward operating pull direction130, the control system110engages to rotate the head roller108in a direction to raise the covering100. As the user pulls on the pull cord120in the upward operating pull direction130, the operating cord124is pulled from the control system110housed in the head rail assembly112. The distance a user may pull the pull cord120and operating cord124is limited by the length of the operating cord. Once the user releases the pull cord, the control system automatically retracts the operating cord back into the head rail assembly until the stopper or coupler126abuts the head rail assembly.

As shown inFIGS. 2,7E, and7F, the upward distance the bottom rail122moves is dictated by the distance the pull cord120and operating cord124are pulled, the rotational mechanical advantage provided by the control system110, and the diameter of the head roller108. The mechanical configuration of the control system110and the diameter of the head roller108combine to determine the upward distance the covering moves in response to a distance that the operating cord is pulled. As such, in one embodiment, the control system mechanical configuration and the head roller diameter combined to provide increased mechanical advantage and reduced speed when raising the covering and increased speed in the downward direction when operating force requirements are less. For example, as shown inFIG. 2, the control system configuration and the head roller diameter are such that they provide a 2:1 mechanical advantage. As a result, in order to move the covering an upward distance of “X,” the operating cord124must be pulled a distance of “2X .” As can be understood by those skilled in the art, a wide range of other mechanical advantages are possible depending on the combination of the control system mechanical configuration and the head roller diameter.

Once the bottom rail122is raised to the desired position, the user may release the pull cord120. Upon release of the pull cord, the operating cord is automatically retracted into the head rail assembly112by the control system110. The control system also includes a braking feature to hold the covering in position once the user releases tension from the pull cord. If the user pulls the pull cord such that the operating cord is extended to its full length, and the bottom rail does not move the desired distance upward, the user can allow the operating cord to retract into the head rail and then pull again on the pull cord to continue raising the bottom rail122. This process can be repeated until the bottom rail122has reached the desired position.

In order to lower the covering, as shown inFIGS. 3,6E, and6F, a user grasps the pull cord120and pulls downward in a slightly left angular diagonal direction to move the covering in the downward direction, also referred to as the downward operating pull direction132. As discussed in more detail below, by pulling in the downward operating pull direction132, the control system110engages to rotate the head roller108in a direction to lower the covering. As the user pulls on the pull cord in the downward operating pull direction132, the operating cord124is pulled in unison from the control system110housed in the head rail assembly112. The distance a user may pull the pull cord120and operating cord124is limited by the length of the operating cord, and the control system automatically retracts the operating cord back into the head rail assembly until the stopper or coupler126abuts the head rail assembly once the user releases the pull cord.

As shown inFIGS. 3,6E, and6F, the downward distance the bottom rail122moves is dictated by the distance the pull cord120and operating cord124are pulled, the mechanical advantage provided by the control system110, and the diameter of the head roller108. As similarly described above with reference to upward movement of the covering, the mechanical configuration of the control system110and the diameter of the head roller108combine to determine the downward distance the covering moves in response to a distance that the operating cord is pulled. For example, as shown inFIG. 3, the control system configuration and the head roller diameter are such that they provide a 1:1 mechanical advantage. As a result, in order to move the covering a downward distance of “Y,” the operating cord124must be pulled a distance of “Y.” As can be understood by those skilled in the art, a wide range of other mechanical advantages are possible depending on the combination of the control system mechanical configuration and the head roller diameter. Also, the present invention can be configured to provide identical or different mechanical advantages for upward and downward movement of the covering100.

Once the bottom rail122is lowered to the desired position, the user may release the pull cord120. Upon release of the pull cord, the operating cord124is automatically retracted into the head rail assembly112by the control system110. The control system's braking feature mentioned above holds the covering in position once the user releases tension from the pull cord. If the user pulls the pull cord such that the operating cord is extended to its full length and the bottom rail does not move the desired distance downward, the user can allow the operating cord to retract into the head rail and then pull again on the pull cord to continue lowering the bottom rail. This process can be repeated until the bottom rail has reached a desired position.

d. Head Roller and Covering Connected Thereto

As previously mentioned, the covering100is connected with the head roller108, and depending upon which direction the head roller rotates, the covering100is either wrapped onto the head roller108or unwrapped from the head roller108. As shown inFIGS. 4,5A, and6F, the head roller108is hollow and generally tubular-shaped. The head roller is provided with two exterior channels134.

As illustrated inFIG. 6F, each exterior channel134has a wide inner space136and a narrow opening138defined by opposing walls140on the outer surface of the head roller108. Each exterior channel134extends longitudinally along the entire length of the head roller108. The first fabric sheet102and the second fabric sheet104of the covering100are provided with flat strips142adapted to fit inside the wide inner spaces136of the exterior channels134and held in position by walls140of the exterior channels134. The flat strips142can be made from stiff material, such as metal or plastic.

The first fabric sheet102and the second fabric sheet104are connected with the head roller108by sliding the flat strips142into the exterior channels134from either end of the head roller108, such that the first fabric sheet102and the second fabric sheet104exit the exterior channels134through the narrow opening138. It is to be appreciated that the head roller108and the covering100may utilize various configurations to connect the head roller with the covering. For example, other such configurations are described in U.S. Pat. No. 5,320,154, which is hereby incorporated in its entirety as if fully disclosed herein.

e. Head Rail Assembly

As shown inFIGS. 4 and 5A, the left end cap114and the right end cap116fasten to cut edges of the front rail118. The left end cap114and the right end cap116also have an inner side144and outer side146. Extended edges148extend perpendicularly from the inner sides144of the left end cap114and the right end cap116and are adapted to be press fit into slots located on the front rail118. It is to be appreciated that extended edges may be configured differently for various shaped front rails. The head roller108is supported from the head rail assembly112(shown inFIG. 1) by the control system110connected with the right end cap116and a cylindrical extension150rotatably connected with the left end cap114. Although the present invention is depicted and described with the control system connected with the right end cap, it is to be appreciated that the control system may also be connected with the left end cap in other arrangements of the invention.

f. Head Roller Support

Referring toFIG. 5A, the cylindrical extension150is supported on a rotatable left end cap shaft (not seen) extending from the inner side144of the left end cap114through an extension aperture152located in the cylindrical extension150. A fastener (not shown) passing into the extension aperture152may be used to secure the cylindrical extension150to the left end cap shaft. As such, the cylindrical extension150can freely rotate either clockwise or counterclockwise. A longitudinal inner groove154is located on the inner wall156of the head roller108and extends the entire length of the head roller. Two longitudinal spaced ridges158on the exterior surface160of the cylindrical extension150are adapted to be received in the longitudinal inner groove154on a left end portion162of the head roller108. As such, the cylindrical extension150rotates along with the head roller108. The cylindrical extension150is also provided with two radially extending tabs164to prevent the flat strips142(seeFIG. 6F) from moving longitudinally inside the exterior channels134on the head roller108.

As shown inFIGS. 4,5C and5C′, and discussed in more detail below, a circular recess166is located on the inner side144of the right end cap116for receiving a portion of the control system110. As illustrated inFIGS. 4 and 5B, a rotator spool168, as will be described in more detail later and having rotation controlled by the control system110, includes a longitudinal fin170located on its exterior adapted to cooperatively engage the longitudinal inner groove154at a right end portion172of the head roller108. As such, rotation of the rotator spool168causes the head roller108to rotate.

g. Control System Assembly Structure Overview

As can be understood fromFIGS. 4,5B,5C and5C′, the control system110includes an input assembly174, a transmission176, and an output assembly178cooperatively engaging to convert linear movement of the pull cord120imparted by a user into rotational movement of the head roller108in the required direction to provide movement of the covering100in the desired direction and distance. The input assembly174converts linear movement of the pull cord120into rotational movement, which is imparted to the transmission176. The input assembly174also engages the transmission176to effect the direction of rotational output from the transmission176. The transmission176, in turn, imparts rotational movement to the output assembly178. The output assembly178interfaces with the head roller108to rotate the head roller in the direction dictated by the transmission176and to provide the braking feature that holds the head roller in position. It is to be appreciated that rotational movement transferred between the input assembly, the transmission, and output assembly may be accomplished with any suitable motion transfer elements, such as a gears and couplings. It is to be appreciated that the components described herein may be constructed from various materials. For example, some embodiments of the present invention utilize materials having the low flexible modulus characteristics of a thermoplastic elastomer polymer. Another embodiment utilizes high density polyethylene.

A detailed structural description of the input assembly174is provided below, followed by detailed descriptions of the transmission176and the output assembly178. To assist in better understanding the structural details of the control system, reference is made throughout to the various figures depicting the control system in disassembled and assembled states. For instance,FIGS. 5B,5C and5C′ show an exploded isometric view of the control system.FIG. 6is a cross-sectional view of the assembled control system engaged to lower the window covering, taken along line6-6inFIGS. 1 and 4.FIGS. 6A-6Gdepict various cross sectional views taken along the length of the control system depicted inFIG. 6.FIG. 7is a cross-sectional view of the assembled control system engaged to raise the covering, taken along line7-7inFIGS. 1 and 4.FIGS. 7A-7Fdepict various cross sectional views taken along the length of the control system depicted inFIG. 7. Descriptions of the rotations of various components of the control system (i.e. clockwise or counterclockwise) are always based on the reference point of looking toward the inner side144of the right end cap116.

h. Input Assembly Overview

The structure and operation of the input assembly174will now be discussed in detail. As shown inFIGS. 4,5B,5C and5C′, the input assembly174includes the pull cord120connected with the operating cord124through the stopper or coupler126, a cord guide arm180, a shift arm182, a cord pulley184, a clock spring186, an axle188, and a cord spool190, all cooperatively engaging to convert linear movement of the pull cord120into a rotational movement of the cord spool190, which is imparted to the transmission176. As discussed in more detail below, the operating cord124extends from the stopper or coupler126and passes through the cord guide arm180, the shift arm182, and the pulley184from where it is wrapped around the cord spool190. As a user pulls on the pull cord120to move the covering100in the desired direction, the operating cord124is unwound from the cord spool190. As will be described in detail later, after the user releases tension from the pull cord120and operating cord124, the clock spring186, cord spool190, and axle188cooperatively engage to automatically wind the operating cord124back onto the cord spool190. The operating cord124is automatically retracted to a point where the stopper or coupler126abuts the cord guide arm180. Depending on whether the user pulls the pull cord in the upward operating pull direction130or the downward operating pull direction132, the shift arm182pivots to engage the transmission176, which dictates the direction in which the head roller108is rotated.

As shown inFIG. 4, a tassel128may be connected with the pull cord120to allow a user to more easily grasp the pull cord when operating the control system110. Various tassel configurations may be utilized. For example, the tassel128shown inFIG. 4has four sides192sloping toward each other and connecting with a flat top surface194having a tassel cord aperture196located therein. The pull cord120extends from a first knot198located at a first end200of the pull cord120and from the inside of the tassel128through the tassel cord aperture196. The first knot198is tied such that it is too large to pass through the tassel cord aperture196. As such, the first knot198engages the flat top surface194from inside the tassel128in order to connect the tassel with the pull cord. The tassel128can be constructed from various types of materials, such as plastic or rubber. Depending on how much force the control system imparts on the pull cord when automatically retracting the operating cord, it may or may not be desirable to construct the tassel from a lightweight material. It is to be appreciated that the position of the tassel can be adjusted by simply moving the location of the first knot on the pull cord.

As shown inFIG. 4, the stopper or coupler126may be in the form of the releasable clasp126. As such, the pull cord120extends from the tassel128and connects with a first portion202of the releasable clasp126. The pull cord passes120through a first clasp cord aperture204located in the bottom of the first portion202of the releasable clasp126. A second knot206tied in a second end208of the pull cord120prevents the pull cord from passing back through the first clasp cord aperture204, which acts to connect the pull cord to the first portion202of the releasable clasp126.

The first portion202of the releasable clasp releasably connects with a second portion210of the releasable clasp126. A first end212of the operating cord124is connected with the second portion210of the releasable clasp126by having a first knot214tied in the first end212of the operating cord124that is too large to pass through a second clasp cord aperture216located in the second portion210of the releasable clasp126.

The first portion202of the releasable clasp126can be configured to separate from the second portion210of the releasable clasp126when excessive tension is applied to the pull cord120. As such, the releasable clasp126can act to reduce strangulation hazards as well as protect the control system110from damage caused by pulling too hard on the pull cord120.

As shown inFIG. 4, the first portion202of the releasable clasp126is a U-shaped member202having a base220with two arms222extending upward therefrom. The arms222of the first U-shaped member202are configured such that the arms222can deflect inwardly toward each other and outwardly away from each other. An inwardly extending tab224is located toward the end of each arm222on the first U-shaped member202.

The second portion210of the releasable clasp126is also a second U-shaped member210having a base228with two arms230extending downwardly therefrom. Ledges232are also located on opposing sides of the base228of the second U-shaped member210. The tabs224located on the arms222of the first U-shaped member202are adapted to cooperatively engage the ledges232on the base228of the second U-shaped member210to releasably connect the first portion202of the releasable clasp126with the second portion210of the releasable clasp126.

In one form, the releasable clasp is configured such that the tabs224slope downward as they extend inwardly toward each other from the arms220. The ledges232can also be configured to receive the downward sloping tabs224. In this configuration, the tabs224interacting with the ledges232act to pull the arms222together in response to tension in the pull cord120. As such, the releasable clasp acts to resist separation of the first portion202from the second portion210as the tension in the pull cord increases. The releasable clasp can further be constructed such that the first portion202will break at a predetermined tension in the pull cord. For example, in one embodiment, the first portion of the releasable clasp is constructed to break when the tension in the pull cord reaches 30 pounds.

In another form, the releasable clasp126is configured such that when excessive tension is applied to the pull cord120, forces resulting from the tension exerted between the tabs224and the ledges232will cause the arms222of the first U-shaped member218to move outwardly away from each other until the tabs224disengage from the ledges232, causing the first portion202to separate from the second portion210of the releasable clasp126.

The various elements of the input assembly174are supported by the right end cap116. As shown in FIGS.5C and5C′, the circular recess166is defined by a partially circular wall234extending from the inner side144of the right end cap116. A first end cap shaft236, a second end cap shaft238, and a third end cap shaft239are integrally connected with and extend perpendicularly from the inner side144of the right end cap116. As such, the first end cap shaft236, the second end cap shaft238, and the third end cap shaft239do not rotate.

As shown in FIG.6BB, the cord guide arm180acts to provide outboard support for the second end cap shaft238. Specifically, a cylindrical spacer294extends perpendicularly from the cord guide arm180and includes a cylindrical hole297. The second end cap shaft238is received within the cylindrical hole297when the cord guide arm180is assembled onto the right end cap16.

As discussed in more detail below, the assembly comprising the cord spool190, the clock spring186, and the axle188(seeFIG. 5B) is rotatably supported by the first end cap shaft236. The second end cap shaft238passes through the cylindrical hole292of the pulley184to rotatably support the pulley184. The shift arm182is pivotably supported on the third end cap shaft239.

Although a detailed structural description of the axle188follows, it should be noted that the axle188interfaces with the input assembly174, the transmission176, and the output assembly178. As such, additional descriptions of the various functions performed by the axle will be described below separately as part of the detailed descriptions of the input assembly, the transmission, and the output assembly. It is to be appreciated that the axle188can be made from various suitable materials. For example, the axle in one embodiment of the present invention is made from a polycarbonate filed with a polymer such as PTFE or similar material.

As shown inFIG. 5B, the axle188may include a plurality of outer surfaces defined along its length by varying diameters. Each outer surface is directed to a function more particularly described below. The axle188shown inFIG. 5Bincludes a first surface240, a second surface242, a flange244, and a third surface246. The first surface is separated from the second surface242by the flange244. The second surface is separated from the third surface246by a shoulder430.

In some embodiments of the present invention, the first surface240may have a slightly smaller diameter than the second surface242. For example, in one particular embodiment, the first surface has a diameter that is 0.081 inches less than the second diameter. A second surface spacer248is located where the second surface242and the flange244join. The third surface246may have a smaller diameter than the first surface240and the second surface242, and may also be configured to taper to yet a smaller diameter until reaching a second end250of the axle188.

As further illustrated inFIG. 5B, a passage252is located through the center of the axle188. The passage opens through a first end254and the second end250of the axle188. As can be understood from FIGS.6and6AA, the passage252is grooved at the first end254and is adapted at the second end250to receive a fastener256. As shown inFIGS. 5C,5C′ and6AA, the outer surface of the first end cap shaft236is grooved to define a plurality of longitudinal ridges258extending radially from the circumference. The groove surface of the first end cap shaft236is adapted to cooperate with a correspondingly shaped grooved female opening in the first end254of the axle188. As such, the longitudinal ridges258prevent the axle188from rotating relative to the first end cap shaft236.

l. Cord Spool & Clock Spring Connection

The structural and cooperative relationship between the cord spool190, the clock spring186, the axle188, the pulley184, the shift arm182, the cord guide arm180, and the operating cord124of the input assembly174will now be described. As shown in FIGS.5C,5C′ and5G, the cord spool190is disc-shaped and includes a first side260and a second side262. The first side260of the cord spool190includes a circular cavity264adapted to store the clock spring186, and the second side262of the cord spool190includes a sun gear266integrally attached thereto. As such, the cord spool190and the sun gear266rotate together. An opening268is located in the center of the cord spool190and is adapted to accept a flange270integrally connected with a planet carrier272(seeFIG. 5K), which is part of the transmission176discussed below. When assembled, the cord spool190is rotatably supported on the flange270, which surrounds the first surface240of the axle188.

As shown inFIGS. 5C,5C′ and5G, the cord spool190includes a groove274in the outer circumference adapted to receive the operating cord124wound thereupon. As shown inFIG. 6Aand discussed in more detail below, the operating cord124is wound clockwise (as viewed by looking toward the inner side144of the right end cap116) onto the groove274of the cord spool190. As such, when the operating cord124is unwound from the cord spool190(i.e. when a user pulls on the pull cord), the cord spool rotates counterclockwise.

As shown inFIG. 6A, a second knot276tied in a second end278of the operating cord124is located in the circular cavity264. The operating cord124extends from the second knot276and passes through a cord notch280and into the groove274. The second knot276prevents the operating cord124from slipping through the cord notch280, thus connecting the second end278of the operating cord124to the cord spool190.

As shown inFIGS. 5C,5C′,5G, and6A, the clock spring186is stored inside the circular cavity264of the cord spool190. The clock spring functions to automatically retract the operating cord124onto the cord spool when tension is released from the pull cord120. The clock spring186includes a first tang282located in the outer winding of the clock spring186, and a second tang284located in the inner winding of the clock spring186. The first tang282engages a first clock spring recess286located on the cord spool190to connect the clock spring with the cord spool. The second tang284engages a second clock spring recess288on the first surface240of the axle188to connect the clock spring with the axle.

When a user pulls on the pull cord120, which in turn unwinds the operating cord124from the cord spool190, the cord spool rotates counterclockwise. Because the clock spring186is fixed at the second tang284by the axle188, the clock spring contracts from an expanded state as the cord spool rotates counterclockwise. As such, rotation of the cord spool coils the clock spring to the extent the operating cord is wound thereupon. When tension is released from the pull cord and operating cord, the cord spool is rotated clockwise by the expanding clock spring to rewind the operating cord back onto the cord spool. As can be understood fromFIGS. 5C,5C′,6and6A, when the control system110is assembled with its components, the axle188is inserted into opening268of the cord spool190and wound slightly to place a pre-load on the clock spring186. This pre-load on the clock spring assures that some tension is always maintained on the operating cord when the system is not in use.

m. Operating Cord Path from Spool to Clasp

As shown inFIGS. 5C,5C′ and6A, the operating cord124passes from the cord spool190to wrap clockwise partially around a groove290in the outer circumference of the pulley184. From the pulley184, the operating cord124exits the head rail assembly112through the cord guide arm180.

As previously mentioned, the shift arm182is pivotally supported off the third end cap shaft239, and the pulley184is rotatably supported off the second end cap shaft238. The cord guide arm180acts to provide outboard support for the second end cap shaft238. As shown in FIGS.5C and5C′, the pulley184has a center opening292adapted to fit around the second end cap shaft238.

When assembled, the pulley cooperates with the second end cap shaft to enable the pulley to freely rotate about the second end cap shaft. The shift arm cooperates with the third end cap shaft to enable the shift arm to freely pivot about the third end cap shaft. Thus, the third end cap shaft is a bearing surface for the shift arm opening, enabling the shift arm to freely pivot on the third end cap shaft. As mentioned above and as described in more detail below, the pivotal position of the shift arm determines whether the shift arm engages the transmission176, which in turn, dictates the direction in which the head roller108is rotated.

As shown inFIG. 6A, the inner side144of the right end cap116includes a first cord barrier wall298, which is a semicircular-shaped structure integral to the right end cap formed partially from the extended edges148(seeFIG. 4). The first cord barrier wall298extends from the inner side of the right end cap. It will be appreciated that the outer circumferential edge of the pulley184is closely proximate to the first cord barrier wall298, but does not engage it. The close proximity of the surfaces of the pulley and the first cord barrier wall is accomplished by the close tolerances between the placement of pulley184and the second end cap shaft238. It is to be appreciated that the mounting of the pulley upon the second end cap shaft238places the outer circumferential edge of the pulley184closely proximate to the first cord barrier wall298.

In one embodiment of the present invention, the outer circumferential edge of the pulley184is placed proximate to the first cord barrier wall298at a distance of less than 0.1 operating cord diameters. This close proximity prevents the operating cord124from escaping from the groove290of the pulley184and thereby becoming trapped between the pulley and the wall298. Thus, as the operating cord124travels from the cord spool190over the pulley184, the pulley is free to rotate, providing a low friction surface for the operating cord, but preventing the operating cord from becoming trapped between the remaining proximate elements.

n. Shift Arm

As shown inFIGS. 5C-5Eand5M-5V, the shift arm182includes a cylindrical portion299and a side wall portion300, which perpendicularly intersects the outer circumferential surface301of the cylindrical portion299near the left end of the cylindrical portion299. The cylindrical portion299includes a flange302and a cylindrical hole303. The flange302perpendicularly extends from the outer circumferential surface301at the left end of the cylindrical portion299. The cylindrical hole303extends through the cylindrical portion299and receives the third end cap shaft239such that the shift arm182may pivot about said shaft239.

The side wall portion299includes a first leg304, a second leg305and a wall section306perpendicularly extending from the forward edge of the side wall portion299. The first leg304angles rearwardly from the cylindrical portion299to terminate with a pawl tooth307. The second leg305extends rearwardly from the wall section306at a slightly obtuse angle to form a boss308.

As best understood fromFIG. 5N, the boss308includes a first cord engagement surface309that is generally vertically oriented and arcuately transitions from an orientation that is generally parallel to the vertical planar surfaces of the wall section306to an orientation that is generally oblique to the vertical planar surfaces of the wall section306and the side wall portion300. As can be understood fromFIGS. 5D,5U and5V, the arcuate transition of the first cord engagement surface309occurs as the second leg305extends downwardly to form the boss308. As best understood fromFIG. 5N, the first cord engagement surface309faces generally rearwardly.

As illustrated inFIGS. 5D,5E and5N, an arm310extends rearwardly and generally perpendicularly from the right edge of the wall section306. In one embodiment, as best understood fromFIG. 5N, the arm310extends to the left to perpendicularly intersect the right vertical planar surface of the first leg304. The arm310includes a second cord engagement surface311that faces generally forwardly and includes a first section312and a second section313.

The first section312is adjacent the right planar surface of the first leg304, and the second section313is adjacent the rearward planar surface of the wall section306. The first section312is generally linear as it extends from the first leg304to the second section313. The first section forms an acute angle with the right vertical planar surface of the first leg304. The second section313arcuately transitions from the first section312to extend generally perpendicularly into the rearward vertical planar surface of the wall section306.

n. Shift Arm Operation

To begin an operational sequence, a pull force upon the operating cord124causes the pulley184to rotate. However, pulling the operating cord124downward to the right or left determines which direction the shift arm182will pivot and whether the pawl tooth307will engage or not engage the teeth314of the planet carrier272. As indicated in FIG.6AAA, when a user pulls on the pull cord, the operating cord124is unwound from the cord spool190, which turns the cord spool in a counterclockwise direction. The operating cord124feeds off the cord spool190to pass over the pulley184between the first cord barrier wall298and the pulley184and down between the cord engagement surfaces309,311of the shift arm182.

As can be understood fromFIGS. 3,5N,5O,5Q,5S,5U,6B,6BB and6BBB, when the operating cord124is displaced downwardly and to the left (i.e., in the downward operating pull direction132) as shown in FIGS.3and6BB, the operating cord124engages the first cord engagement surface309on the boss308. This causes the shift arm182to pivot counterclockwise (as viewed inFIG. 6B) about the second end cap shaft239such that the operating cord124ends up residing between the first section312of the second cord engagement surface311and the right vertical planar surface of the wall portion300(i.e., the area indicated by arrow A inFIG. 5N). As a result, the pawl tooth307does not engage the teeth314on the planet carrier272as depicted inFIG. 6B.

As can be understood fromFIGS. 2,5N,5R,5T,5V,7A,7AA and7AAA, when the operating cord124is displaced downwardly and to the right (i.e., in the upward operating pull direction130) as shown in FIGS.2and7AA, the operating cord124engages the second cord engagement surface311on the arm310. This causes the shift arm182to pivot clockwise (as viewed inFIG. 7A) about the second end cap shaft239such that the operating cord124ends up residing between the second section313of the second cord engagement surface311and the rearward vertical planar surface of the wall section306(i.e., the area indicated by arrow B inFIG. 5N). As a result, the pawl tooth307is forced into engagement with the teeth314on the planet carrier272as depicted inFIG. 7A.

As can be understood fromFIG. 5E, the mass of the wall portion300, which is offset from the axis of the cylindrical hole303, causes the shift arm182to rotate clockwise about said axis as viewed inFIG. 5E. As a result, the pawl tooth307is biased rearwardly and into engagement with the teeth314of the planet carrier272, even without pulling the operating cord124in the upward operating pull direction130.

o. Cord Guide Arm

As shown inFIGS. 5C,5C′,5H, and5J the cord guide arm180is an elongate element having a right side322(depicted inFIG. 5J) and a left side324(depicted inFIG. 5H). As shown inFIG. 5H, the left side324includes a rib326disposed longitudinally thereon to add structural strength along the length of the cord guide arm. In one embodiment, a cylindrical hole296is located at the upper end of the cord guide arm. The cylindrical hole296is adapted to receive the female end of a cylindrical spacer294as shown in FIG.6BB. In another embodiment, the cylindrical spacer294is an integral part of the cord guide arm180and the cylindrical hole296does not exist. As discussed below, when assembled, the cord guide arm is held in a fixed position relative to the right end cap116.

As shown in FIGS.5J and6BB, the cylindrical spacer294extends perpendicularly from the right side322and includes a cylindrical hole297, which receives the second end cap shaft238and provides outboard support therefor. The second end cap shaft238is received within the center opening292of the pulley184and serves as a support surface about which the pulley184may rotate.

Many points of engagement between the cord guide arm180and the right end cap116are provided to fix the cord guide arm in proper alignment with the shift arm182. As shown inFIGS. 5C,5C′,5H and5J, the cord guide arm180includes two fingers330adapted to engage with corresponding slots332on the right end cap116. The fingers330are configured to “snap fit” into the slots332for fixedly retaining the cord guide arm in a fixed position relative to the right end cap. A brace334is located between the fingers330on the cord guide arm. The brace helps to further retain the cord guide arm in a fixed relationship with respect to the right end cap upon assembly of the components. The brace334includes a notch336for engagement with an extended edge rib (not shown) on the right end cap116.

As shown inFIGS. 4,5C,5C′,5H,5J and6AA, a filler338and a snap340project from the right side322. The filler and the snap also maintain the cord guide arm in a fixed relationship with right end cap. The filler338is adapted to substantially fit within a recess342on the right end cap116, and the snap340is adapted to engage a ledge344on the right end cap116. As will be appreciated, as the cord guide arm is assembled into its operational position, the snap is brought to a forced engagement with the ledge by sliding over the ledge and snapping into position.

p. Parked Position

As shown inFIGS. 5C,5C′,5H and5J, a horn346is located at the lower end of the cord guide arm180. A horn opening348is located at the lower end of the horn346. The horn opening348is a curved and flared opening formed by horn walls350. The horn opening348is adapted to stop and retain the releasable clasp126in a “parked” position (see FIGS.6BBBB and7F).

As mentioned above, when the pull cord120is not being pulled, the stopper or coupler126is drawn against the cord guide arm180, or more particularly, the horn opening348, and is held in place by tension in the operating cord124generated by the clock spring186. In one embodiment, the parked position of the stopper or coupler126urges the operating cord to directly overlay the first cord engagement surface309of the boss308on or near the extreme tip of the boss308, as shown in FIG.6BBBB. As a result, when the pull cord120is not being pulled, the shift arm182is maintained in a position wherein the pawl tooth307does not engage the teeth314of the planet carrier272.

As previously discussed, when a user pulls on the pull cord120, the cord engagement surfaces309,311of the shift arm182cooperate with the operating cord124such that the shift arm182is enabled to pivot and engage the pawl tooth304with the transmission, or the shift arm182is prevented from pivoting to engage the pawl tooth304with the transmission. However, in one embodiment, when the pull cord120is not being pulled and the releasable clasp126is in the parked position depicted in FIGS.6BBBB and7F, the flared opening348is configured to urge the operating cord124to directly overlay the first cord engagement surface309of the boss308on or near the extreme tip of the boss308, as shown in FIG.6BBBB. When the pull cord120is being pulled, the flared opening348of the cord guide arm180urges the user to pull on the pull cord and operating cord in either the upward operating pull direction130or the downward operating pull direction132, as shown inFIGS. 2 and 3.

If the pull direction is in the upward operating pull direction130(seeFIG. 2), the operating cord124moves from the parked position and contacts the second cord engagement surface311of the shift arm182as discussed above and shown in FIGS.6BBBB,7A,7AA and7AAA. However, as shown inFIGS. 6B,6BB,6BBB and6BBBB, if the pull direction is in the downward operating pull direction132(seeFIG. 3), the operating cord124remains in contact with the first cord engagement surface309of the boss because the parked position already had the operating cord124in contact with the tip of the boss309.

q. Final Summary of Input Assembly

To summarize the operational description of the input assembly, as a user pulls on the pull cord120to move the covering100in the desired direction, the operating cord124is unwound from the cord spool190, causing the cord spool to rotate in a counterclockwise direction. The operating cord passes over the pulley184and between the cord engagement surfaces309,311of the shift arm182. Pulling the operating cord124downwardly right or left determines the direction of the pivot for the shift arm and whether the pawl tooth307will engage the teeth of the planet carrier272.

If the user pulls the pull cord in the upward operating direction130, the shift arm is allowed to pivot such that the pawl tooth307on the shift arm engages the transmission, causing the head roller108to rotate in a direction to wrap the covering100onto the head roller, as will be explained more fully later. Alternatively, if the user pulls the pull cord in the downward operating direction132, the shift arm is prevented from pivoting to engage the pawl tooth with the transmission176, causing the head roller to rotate in a direction to unwrap the covering from the head roller.

Rotation of the cord spool190operates as an input to the transmission, which imparts rotational movement to the output assembly178and the head roller108. After the user releases tension from the pull cord and operating cord, the clock spring186causes the cord spool to automatically wind the operating cord back onto the cord spool. As the operating cord winds back onto the cord spool, the operating cord is automatically retracted until the stopper or coupler126engages the horn opening348of the cord guide arm180, placing the operating cord back into the parked position over the first cord engagement surface309.

r. Transmission Overview

The structure and operation of the transmission176will now be discussed in detail. As shown in FIGS.5C and5C′, the transmission includes a sun gear266integrally connected with the second side262of the cord spool190, a planet carrier272, four planet gears352, a spider354, and a ring gear356(seeFIG. 5B). These components all cooperatively engaging to convert rotational movement of the cord spool into rotational movement of the ring gear, which imparts rotational movement to the output assembly178.

As discussed in more detail below, a user pulling on the pull cord120causes the cord spool to rotate counterclockwise (see FIG.6AAA). Because the sun gear is integral with the cord spool, the sun gear also rotates in a counterclockwise direction.

If the user pulls the pull cord in the upward operating direction130(seeFIG. 2), the shift arm182pivots until the pawl tooth307engages ratchet teeth314on the planet carrier272, which prevents the planet carrier from rotating (seeFIG. 7A). Counterclockwise rotation of the sun gear causes clockwise rotation of the four planet gears352about their respective axes (seeFIG. 7B). The four planet gears353in turn engage the ring gear356to turn the ring gear in a clockwise direction.

Alternatively, if the user pulls the pull cord in the downward operating direction132(seeFIG. 3), the shift arm182does not pivot to engage the pawl tooth307with the planet carrier272(seeFIG. 6B), allowing the planet carrier to rotate. As such, counterclockwise rotation of the sun gear initially causes clockwise rotation of the four planet gears about their respective axes as the four planet gears orbit counterclockwise about the axis of the sun gear (seeFIG. 6G) due to the planet carrier272rotating counterclockwise as a result of frictional resistance between interfacing surfaces of the planet carrier272and the cord spool190. After the planet carrier has rotated counterclockwise for a brief period, the planet carrier engages the spider354to turn the spider in a counterclockwise direction, which engages the ring gear356to turn in a counterclockwise direction (seeFIG. 6C). At this time, the four planet gears cease to rotate about their respective axes and simply continue to orbit counterclockwise about the axis of the sun gear as the planet carrier rotates counterclockwise (seeFIG. 6G). Adequate engagement of the planet carrier with the spider to facilitate the cord spool, planet carrier and ring gear turning counterclockwise as one integral unit is made possible by the resistance to motion of the ring gear by frictional drag associated with the wrap springs.

As discussed in more detail below, the spider acts as a part time one-way clutch activated by the planet carrier to rotate the ring gear. As such, when the spider is deactivated, the spider would not interfere with rotation of the ring gear in either the clockwise or counterclockwise directions.

As mentioned above and as shown inFIGS. 5C,5C′ and7B, the sun gear266is integrally connected with the second side262of the cord spool190and is adapted to engage four planet gears352on the planet carrier272. Although four planet gears are depicted and described with reference to the transmission, it is to be appreciated that the transmission can be configured to include more than or less than four planet gears. The planet carrier is disc-shaped and has a first side358and a second side360with a center circular opening362passing there through, as shown inFIGS. 5C,5C′ and5K. A series of ratchet teeth314are located on the periphery of the planet carrier. The ratchet teeth314are adapted to engage with the pawl tooth304on the shift arm182. The sun gear266is adapted to be received in the center circular opening362of the planet carrier272from the first side358. The flange270inside the center circular opening includes an inner surface364adapted to receive the first surface240of the axle188and includes an outside surface366to act as a bearing surface for the sun gear266. The length of the flange270, the width of the sun gear266, and the depth of the center circular opening362are substantially equal to allow the flange and the sun gear to fit together so as to enable the sun gear to engage the planet gears352.

As shown inFIGS. 5C,5C′ and7B, the second side360of the planet carrier includes a circular shaped raised structure370adapted to accept the four planet gears352. The raised structure370has four sun gear openings372spaced at ninety-degree intervals there around. Planet gear axles374extending from the second side360of the planet carrier272and are radially positioned to correspond with the location of the sun gear openings372in the raised structure370. The planet gears are configured with center holes376adapted to receive the planet gear axles374. As such, when the planet gears are positioned on the planet carrier axles, the planet gears project geared surfaces into the sun gear openings. Moreover, upon inserting the sun gear into center circular opening of the planet carrier, the sun gear engages the planet gears. Therefore, rotation of the cord spool190rotates the sun gear266, which rotates the four planet gears352.

t. Engagement of Planet Carrier and Spider

As shown inFIGS. 5C,5C′,5L, and6C, two actuator tabs378extend from the circular raised structure370on the planet carrier272. The actuator tabs378are trapezoidally shaped, each having a small notch380located thereon. The actuator tabs378are adapted to engage the spider354upon rotation of the planet carrier272. The spider354includes a somewhat flexible and resilient body382generally oblong or “football” shape having an open center384with rounded ends386. Arcuate legs388project from the rounded ends386in opposite directions with respect to each other. The legs388may also be flexible and resilient so as to be bendable outwardly or away from the body382. Wedges390located at a distal end of each leg388are adapted to engage the small notches380on the actuator tabs378and the ring gear356upon counterclockwise rotation of the planet carrier272, as discussed in more detail below. Opposite a point of attachment of each leg388is a small stop392adapted to engage the actuator tabs378upon clockwise rotation of the planet carrier272. It is to be appreciated that the spider can be made from various suitable materials. For example, the spider in one embodiment of the present invention is made from a thermoplastic polyester elastomer, such as HYTREL® manufactured by DUPONT®. Other embodiments are made from creep resistant, low modulus, amorphous thermoplastics such as polycarbonate.

The open center384of the spider354is adapted to receive the first surface240of the axle188. The engagement of the first surface of the axle and the open center of the spider is an interference fit. As such, the diameter of the open center384of the spider354is slightly smaller than the outside diameter of the first surface240of the axle188. In one embodiment of the present invention, the diameter of the open center of the spider is 0.016 inches smaller than the outer diameter of the first surface of the axle. The interaction of the spider material with the axle material along with the interference fit create some friction between the spider and the first surface of the axle, but the spider can move around the first surface without binding. The friction between the body of the spider and the first surface of the axle enables engagement of the actuator tabs with the spider upon rotation of the planet carrier in a counterclockwise direction, and disengagement of the spider from the actuator tabs upon rotation of the planet carrier in a clockwise direction.

u. Ring Gear

As previously mentioned, depending upon which direction the user pulls on the pull cord, either the four planet gears352or the spider354cause the ring gear356to rotate in either a clockwise direction or a counterclockwise direction, respectively. As shown inFIGS. 5B and 5F, the ring gear356is defined by a flanged portion394having a first side396and a second side398with a cylindrical portion400extending from the second side398. A cylindrical opening402passes through the flanged portion394and the cylindrical portion400. As shown inFIGS. 5F and 7B, the first side396of the flanged portion394is largely open ended having a first geared lip404adapted to engage the four planet gears352on the planet carrier272. Moreover, the first geared lip is slightly raised from the first side of the flanged portion to form a flange bearing surface406. The flange bearing surface406is adapted to cooperate with a circular groove408on the second side360of the planet carrier272to create a bearing surface as well as an axial support between the planet carrier and the ring gear (see FIGS.5C and5C′).

As shown inFIGS. 5F and 6C, a second geared lip410is located interiorly of the first geared lip404. The second geared lip410has a smaller diameter than the first geared lip404and is adapted to engage the spider wedges390. As previously mentioned, the legs388of the spider354are flexible. As shown inFIG. 6C, counterclockwise rotation of the planet carrier272moves the two actuator tabs378into engagement with the two legs388on the spider354. More particularly, the actuator tabs engage the spider such that the actuator tabs move between the wedges390and the body382of the spider354until the notches380on the actuator tabs378engage the wedges, causing the legs of the spider to flex and bend outwardly from the body of the spider. As the legs388flex and bend outwardly, the wedges390are driven to engage the second geared lip410of the ring gear356. Friction between the body of the spider and the first surface of the axle holds the body of the spider in a fixed position relative to the axle until the actuator tabs adequately engage the legs of the spider. The engagement of the wedges with the second geared lip surface is compressional in that the wedges are driven to fit the second geared lip by outward force of the expanded leg against the actuator tab. Continued rotation of the planet carrier and ring gear in a counterclockwise direction, enables the wedges to remain in a continued compressional engagement with the second geared lip. When the planet carrier rotates in the clockwise direction, friction between the spider body and the first surface of the axle overcomes friction between the actuator tabs and the spider legs, allowing the actuator tabs to disengage from the spider legs, which disengages the spider from the ring gear.

As shown inFIG. 5B, the cylindrical portion400of the ring gear356is defined by three elevated sleeve extensions. A first sleeve extension412extends from the second side398of the flanged portion394. A second sleeve extension414extends from the first sleeve extension412and has a diameter smaller than the first sleeve extension. A third sleeve extension416extends from the second sleeve extension414and has a diameter smaller than the second sleeve extension. Further, the third sleeve extension includes an U-shaped channel418formed therein with two side walls420extending from the second sleeve extension to the end of the third sleeve extension416. As discussed below, the two side walls420function to cooperate with the braking system.

As shown inFIG. 5F, a shoulder422located near the second geared lip410is defined by the connection of the third sleeve extension416and the second sleeve extension414. The shoulder422is adapted to cooperate with the flange244of the axle188to create a thrust bearing between the ring gear356and the axle188. When the ring gear is mounted on the second surface242of the axle188, the shoulder contacts the flange244at an area just outside the circumference of the second surface spacer248. As such, the second surface spacer248helps to maintain the alignment of the axle188with the ring gear356by maintaining the shoulder422in an appropriate thrust bearing position.

v. Summary of Transmission

To summarize the operational description of the transmission176, as a user pulls on the pull cord120to move the covering100in the desired direction, the operating cord124is unwound from the cord spool190, causing the cord spool and the sun gear266to rotate in a counterclockwise direction (seeFIGS. 6A,6AAA,6B, and7A). If the user pulls the pull cord in the upward operating direction130(seeFIGS. 2 and 7A), the shift arm182is allowed to pivot such that the pawl tooth307on the shift arm engages the ratchet teeth314on the planet carrier, which prevents the planet carrier from rotating. As such, the counterclockwise rotation of the sun gear causes the four planet gears352to rotate in a clockwise rotation about their respective axles374(seeFIG. 7B). The rotating planet gears352in turn engage the first geared lip404of the ring gear356to cause the ring gear to rotate in a clockwise direction. Clockwise rotation of the ring gear, which engages the output assembly (seeFIGS. 7C and 7D), causes the head roller108to rotate in a clockwise direction to wrap the covering100onto the head roller.

Alternatively, if the user pulls the pull cord120in the downward operating direction132(seeFIGS. 3 and 6B), the shift arm182is prevented from pivoting to engage the pawl tooth307with the ratchet teeth314on the planet carrier272. This allows the planet carrier to rotate freely about the first surface240of the axle188. As such, counterclockwise rotation of the sun gear266initially causes clockwise rotation of the four planet gears352about their respective axles374as the four planet gears352orbit counterclockwise about the axis of the sun gear266due to the planet carrier272rotating counterclockwise as a result of frictional resistance between interfacing surfaces of the planet carrier272and the cord spool190.

After the planet carrier272has rotated counterclockwise for a brief period, the two actuator tabs378of the planet carrier272eventually engage the legs388on the spider354to turn the spider354in a counterclockwise direction. The actuator tabs378cause the legs388of the spider354bend outwardly away from the body382of the spider until the wedges390on the distal ends of the legs are compressed by the actuator tabs378against the second geared lip410of the ring gear356. As a result, the spider354engages the ring gear356to turn it in a counterclockwise direction, as can be understood fromFIG. 6C. At this time, the four planet gears352cease to rotate about their respective axles374and simply continue to orbit counterclockwise about the axis of the sun gear266as the planet carrier272rotates counterclockwise. Adequate engagement of the planet carrier272with the spider354to facilitate the cord spool190, planet carrier272and ring gear356turning counterclockwise as one integral unit is made possible by the resistance to motion of the ring gear356by frictional drag associated with the wrap springs424. Counterclockwise rotation of the ring gear356, which engages the output assembly178, causes the head roller108to rotate in a counterclockwise direction to unwrap the covering100from the head roller108(seeFIGS. 6C and 6D).

Once the user releases tension from the pull cord120, the clock spring186recoils the operating cord124onto the cord spool190in a clockwise direction. As the cord spool recoils, the planet carrier272moves in a clockwise direction. Rotation of the planet carrier in a clockwise direction disengages the wedges390on the spider legs388from the actuator tabs378on the planet carrier272. As such, the legs contract to their original position relative to the spider body, which disengages the wedges from the second geared lip. Disengagement of the wedges from the second geared lip causes the rotation of the ring gear to cease.

w. Output Assembly Overview

The structure and operation of the output assembly178will now be discussed in detail. As shown inFIG. 5B, the output assembly includes the fastener256, two wrap springs424rotatably supported on the second surface242of the axle188, and the rotator spool168supported by the cylindrical portion400of the ring gear356. These components engage to convert rotational movement of the ring gear into rotational movement of the head roller108. As discussed in more detail below, a user pulling on the pull cord124in the upward operating direction130(seeFIGS. 2 and 7E), causes the ring gear356to rotate in a clockwise direction, which causes the rotator spool168and the head roller108to rotate in a clockwise direction. Alternatively, a user pulling the pull cord in the downward operating direction132(seeFIGS. 3 and 6E) causes the ring gear to rotate in a counterclockwise direction, which causes the rotator spool168and the head roller108to rotate in a counterclockwise direction.

As shown inFIGS. 5B,6D, and7D, two wrap springs424of a spring clutch are adapted to receive the second surface242of the axle188. It is to be appreciated that the number of wrap springs used may vary for different embodiments of the present invention. The inside diameters of the wrap springs are slightly smaller than the outside diameter of the second surface of the axle, which provides a frictional engagement between the second surface and the wrap springs. This frictional engagement enables a braking action for the ring gear356. When the ring gear356is mounted on the axle188, the third sleeve extension416surrounds the wrap springs424such that wrap spring tangs426extend outwardly from the wrap springs424near the side walls inside the U-shaped channel418.

Still referring toFIGS. 5B,6D, and7D, the braking effect of the wrap springs424is released by the side walls420of the U-shaped channel418in the third sleeve extension416of the ring gear356engaging one or a plurality of wrap spring tangs426. As such, the rotational force of the side walls against the wrap spring tangs causes the wrap springs to expand, thereby loosening their frictional engagement on the second surface248of the axle188. The reduced frictional engagement allows rotation of the ring gear356. However, as the force imparted on the wrap spring tangs lessens, the wrap springs contract, thereby tightening their frictional engagement on the second surface of the axle, which provides a braking response. As well as holding the covering in a particular position, engagement of the side walls against the wrap spring tangs also helps to prevent the ring gear from turning too quickly when the user is pulling on the pull cord.

As previously discussed, the diameter of the shoulder422of the ring gear356is slightly larger than the diameter of the second surface spacer248on the axle188. As such, the wrap spring424closest to the spacer is prevented from becoming lodged under the shoulder as the ring gear356rotates. This may be an important function when more than two wrap springs are fitted about the second surface of the axle. In addition, an end lip428on the interior of the third sleeve extension416is adapted to cooperate with a second surface shoulder430of the axle188when the axle is inserted there through, which helps to prevent the wrap springs424from moving in a longitudinal direction along the second surface242of the axle188.

As shown inFIGS. 5B,6D, and7D, the cylindrically-shaped rotator spool168includes a brake housing portion432having a hollow interior at an open end434. Radially spaced longitudinal fins436are located on the outside of the rotator spool. A first longitudinal fin170is adapted to fit within the longitudinal inner groove154of the head roller108, as shown inFIG. 4. A longitudinal boss438is adapted to connect with the interior of the brake housing portion432. Referring back toFIGS. 5B,6D, and7D, the brake housing portion432of the rotator spool168is adapted to be placed over the third sleeve extension416of the ring gear356so the longitudinal boss438fits into the U-shaped channel418between the wrap spring tangs426near the side walls420. As such, when the ring gear rotates in either a clockwise or counterclockwise direction, the longitudinal boss of the brake housing portion of the rotator spool engages the side walls of the U-shaped channel. Thus, the rotator spool rotates in the same direction as the ring gear.

As shown inFIGS. 5B,6, and7, the rotator spool168is secured to the axle188by the fastener256to maintain a thrust connection between the components of the control system. More particularly, the fastener256enters an opening440in the rotator spool and passes through the center of the axle188and screws into the first end cap shaft236. When the components of the control system are assembled on the axle and the axle is installed on the first end cap shaft, the second end250of the axle188extends a slight distance outwardly from the opening440of the rotator spool168. In one embodiment, the axle extends 0.015 inches outwardly from the opening of the rotator spool. As such, when the fastener is screwed into the first end cap shaft, the screw head442does not press against the rotator spool168. As a result, the rotator spool is able to freely rotate.

y. Overall Summary

The above-described control system110assembled on the right end cap116of the head rail assembly112, as shown inFIGS. 6 and 7, allows a user to raise or lower the covering100by pulling on the pull cord120in either the upward operating pull direction130or the downward operating pull direction132. The control system110also allows the user to pull repetitively on the pull cord in the same direction to achieve the desired position of the covering. Once the user releases the pull cord, the control system automatically retracts the operating cord back into the head rail assembly, and the braking system holds the covering in position.

II. Discussion of Second Embodiment

a. General Overview of Second Embodiment

A second embodiment of the covering100and control system110of the present invention will now be discussed.FIG. 8illustrates a second embodiment of the covering100, which includes a first vertical fabric sheet102and a second vertical fabric sheet104. The first fabric sheet102has a series of uniform horizontal folds105that are attached at generally uniform intervals to the second fabric sheet104. As with the first embodiment, the covering100of the second embodiment is suspended from a head rail assembly112that includes a left end cap114, a right end cap116and a control system110that is operated via a pull cord120.

As will be evident to those skilled in the art, the configuration and operation of the control system110for the second embodiment is generally the same as the configuration and operation of the control system for the first embodiment, except, as best understood via a comparison betweenFIGS. 6B,7A,9A,10A,12A and13A, the orientation of the pawl tooth307and the teeth314on the planet carrier272are reversed, and the operating cord124is wound about the 190 cord spool in a reversed direction. Specifically, as shown inFIGS. 9A,10A,12A and13A, the operating cord124is wound counterclockwise about the cord spool190. Because of these differences, the various rotational components of the input assembly174, the transmission176and the output assembly178of the second embodiment rotate in directions opposite from the same components of the first embodiment.

b. Summary of Rotational Movement for Components of the Input, Transmission, and Output Assemblies of the Second Embodiment

With respect to the second embodiment of the control system110, a user pulling on the pull cord120causes the operating cord124to unwind from the cord spool190As a result, the cord spool190rotates clockwise (seeFIGS. 9A and 12A). Because the sun gear266is integral with the cord spool190, the sun gear266also rotates in a clockwise direction.

If the user pulls the pull cord120in the upward operating direction130(seeFIG. 2), the shift arm182pivots until the pawl tooth307engages ratchet teeth314on the planet carrier272, which prevents the planet carrier272from rotating (seeFIGS. 10A and 13A). Clockwise rotation of the sun gear266causes counterclockwise rotation of the four planet gears352about their respective axles374(seeFIGS. 10A and 13A). The four planet gears353in turn engage the ring gear356to turn the ring gear356in a counterclockwise direction. Counterclockwise rotation of the ring gear356, which engages the output assembly178, causes the head roller108to rotate in a counterclockwise direction to wrap the covering100onto the head roller108.

Alternatively, if the user pulls the pull cord120in the downward operating direction132(seeFIG. 3), the shift arm182does not pivot to engage the pawl tooth307with the planet carrier272(seeFIGS. 10A and 13A), allowing the planet carrier272to rotate. As such, clockwise rotation of the sun gear266initially causes counterclockwise rotation of the four planet gears352about their respective axles374as the four planet gears352orbit clockwise about the axis of the sun gear266due to the planet carrier272rotating clockwise as a result of frictional resistance between interfacing surfaces of the planet carrier272and the cord spool190.

After the planet carrier272has rotated clockwise for a brief period, the two actuator tabs378of the planet carrier272eventually engage the legs388on the spider354to turn the spider354in a clockwise direction. The actuator tabs378cause the legs388of the spider354bend outwardly away from the body382of the spider until the wedges390on the distal ends of the legs are compressed by the actuator tabs378against the second geared lip410of the ring gear356. As a result, the spider354engages the ring gear356to turn it in a clockwise direction, as can be understood fromFIG. 6C(which is the same as the second embodiment, except the legs388of the spider354point in a counterclockwise direction, the teeth of geared lip410are inclined in the opposite direction, and the directional arrow would be reversed to indicate clockwise rotational displacement of the ring gear356and head roller108). At this time, the four planet gears352cease to rotate about their respective axles374and simply continue to orbit clockwise about the axis of the sun gear266as the planet carrier272rotates clockwise. Adequate engagement of the planet carrier272with the spider354to facilitate the cord spool190, planet carrier272and ring gear356turning clockwise as one integral unit is made possible by the resistance to motion of the ring gear356by frictional drag associated with the wrap springs424. Clockwise rotation of the ring gear356, which engages the output assembly178, causes the head roller108to rotate in a clockwise direction to unwrap the covering100from the head roller108.

As in the first embodiment, the spider354of the second embodiment acts as a part time one-way clutch activated by the planet carrier272to rotate the ring gear356. As such, when the spider354is deactivated, the spider354would not interfere with rotation of the ring gear356in either the clockwise or counterclockwise directions.

c. Shift Arms

Two different versions of the shift arm182may be employed with the second embodiment of the control system110. The first shift arm version is depicted in FIGS.9A-9AA,9AAAAA,10A-10AAA, and11A-11E. The second shift arm version is depicted in FIGS.12A-12AAA,13A-13AAA, and14A-14E.

As shown inFIGS. 11A-11E, the first version of the shift arm182includes a cylindrical portion500, a block portion502, a first arm504, a second arm, and a pawl tooth307. The cylindrical portion500includes a cylindrical hole508, which extends through the cylindrical portion500and receives the third end cap shaft239such that the shift arm182may pivot about said shaft239(seeFIGS. 9A and 10A). The block portion502extends downwardly and rearwardly from the cylindrical portion500.

As indicated inFIGS. 11D and 11E, in one embodiment of the first version of the shift arm182, the first arm504projects generally horizontally forward from the front side of the block portion502and has one side that is coplanar with the right vertical planar side of the block portion502. The second arm506projects generally horizontally forward from the front side of the block portion502, has one side that is generally coplanar with the left vertical planar side of the block portion502, generally resides in a plane that is generally parallel to the plane in which the first arm504resides, and is located above the first arm504. The pawl tooth307extends generally upward and rearward from the top of the cylindrical and block portions500,502and has one side that is coplanar with the right vertical planar side of the cylindrical and block portions500,502.

As shown inFIGS. 11A-11C, in one embodiment of the first version of the shift arm182, the first arm504projects generally horizontally forward from the front side of the block portion502and has one side that is coplanar with the left vertical planar side of the block portion502. The second arm506projects generally horizontally forward from the front side of the block portion502, has one side that is generally coplanar with the right vertical planar side of the block portion502, generally resides in a plane that is generally parallel to the plane in which the first arm504resides, and is located above the first arm504. The pawl tooth307extends generally upward and rearward from the top of the cylindrical and block portions500,502and has one side that is coplanar with the left vertical planar side of the cylindrical and block portions500,502.

As shown inFIGS. 11A-11E, the first arm504forms a boss504that includes a first cord engagement surface510that is generally vertically oriented and has an orientation generally oblique to the vertical planar surface of the front side of the block portion502. Specifically, in one embodiment, the first cord engagement surface510intersects the vertical planar surface of the front side of the block portion502at a point along said planar surface that is approximately at the lateral midpoint of said planar surface. The first cord engagement surface510extends forwardly along an oblique route to intersect the tip512of the boss504. At the tip512, the first cord engagement surface510arcuately transitions about the tip512to intersect a side surface of the boss504that is generally co-planar with a planar side surface of the block portion502.

As shown inFIGS. 11A-11E, the second arm506forms a bracket506that opens towards the boss504in a direction that is generally parallel to the axis of the cylindrical hole508. The inside surface of the bracket506forms a second cord engagement surface520that is generally vertically oriented and includes a first oblique section520′, a perpendicular section520″, and a second oblique section520′″. The perpendicular section520″ extends perpendicularly forward away from the front vertical planar surface of the block portion502. The first and second oblique sections520′,520′″ extend from opposite ends of the perpendicular section520″, face each other, and diverge as they extend from the perpendicular section520″ to their respective tips.

As shown inFIGS. 14A-14E, the second version of the shift arm182includes a cylindrical portion500, a block portion502, a boss arm504, and a pawl tooth307. The cylindrical portion500includes a cylindrical hole508, which extends through the cylindrical portion500and receives the third end cap shaft239such that the shift arm182may pivot about said shaft239(seeFIGS. 12A and 13A). The block portion502extends downwardly and rearwardly from the cylindrical portion500.

As shown inFIGS. 14A-14E, the boss arm504projects generally horizontally forward from the front side of the block portion502and curves gradually upward. The boss arm504includes a first cord engagement surface510that is generally vertically oriented and has a parallel section510′ and an oblique section510″. The parallel section510′ has an orientation that is generally parallel to the axis of the cylindrical hole508. The oblique section510″ has an orientation that is generally oblique to the parallel section510′. The parallel section510′ arcuately transitions into the oblique section510″, which extends forwardly from the parallel section510′ to a tip512of the boss arm504. The parallel section510′ arcuately transition to the oblique section510″ at a point that is approximately at the lateral midpoint of the shift arm182.

In one embodiment of the second version of the shift arm182, as indicated inFIGS. 14A-14C, the oblique section510″ arcuately transitions about the tip512to a side of the boss arm504that is generally co-planar with the left vertical planar surface of the block portion502. The pawl tooth307extends generally upward and rearward from the top of the cylindrical and block portions500,502and has one side that is coplanar with the left vertical planar side of the cylindrical and block portions500,502.

In one embodiment of the second shift arm182, as indicated inFIGS. 14D-14E, the oblique section510″ arcuately transitions about the tip512to a side of the boss arm504that is generally co-planar with the right vertical planar surface of the block portion502. The pawl tooth307extends generally upward and rearward from the top of the cylindrical and block portions500,502and has one side that is coplanar with the right vertical planar side of the cylindrical and block portions500,502.

d. Operation of the Shift Arms

For a discussion of the second embodiment of the control system110employing the first version of the shift arm182, reference is now made to FIGS.9A-9AA,9AAAAA,10A-10AAA and11A-11E. To begin an operational sequence, a pull force upon the operating cord124causes the pulley184to rotate about the second end cap shaft238. However, pulling the operating cord124downward to the right or left determines which direction the shift arm182will pivot and whether the pawl tooth307will engage or not engage the teeth314of the planet carrier272. When a user pulls on the pull cord, the operating cord124is unwound from the cord spool190, which turns the cord spool in a clockwise direction. The operating cord124feeds off the cord spool190to pass over the pulley184between the first cord barrier wall298and the pulley184and down between the cord engagement surfaces510,520of the shift arm182.

As can be understood fromFIGS. 3,9A-9AA,9AAAAA and11A-11C, when the operating cord124is displaced downwardly and to the left (i.e., in the downward operating pull direction132), the operating cord124engages the first cord engagement surface510on the boss504. This causes the shift arm182to pivot clockwise (as viewed inFIG. 9A) about the third end cap shaft239such that the operating cord124ends up residing against the first cord engagement surface510near or on the tip512of the boss504. In one embodiment, as depicted in FIGS.9AA and9AAAAA, the operating cord124will end up residing against the first cord engagement surface510on the tip512of the boss504near the left planar vertical side of the shift arm182. As a result of the operating cord124engaging the first cord engagement surface510near or on the tip512of the boss504, the pawl tooth307does not engage the teeth314on the planet carrier272, as depicted inFIG. 9A.

As can be understood fromFIGS. 2,10A-10AAA and11A-11C, when the operating cord124is displaced downwardly and to the right (i.e., in the upward operating pull direction130), the operating cord124engages the second oblique section520′″ of the second cord engagement surface520on the second arm506. This causes the shift arm182to pivot counterclockwise (as viewed inFIG. 10A) about the third end cap shaft239such that the operating cord124ends up residing against the perpendicular section520″ of the second cord engagement surface520. As a result, the pawl tooth307is forced into engagement with the teeth314on the planet carrier272as depicted inFIG. 10A.

As can be understood fromFIG. 10A, the mass of the block portion502, which is offset from the axis of the cylindrical hole508, causes the shift arm182to rotate counterclockwise about said axis as viewed inFIG. 9A. As a result, the pawl tooth307is biased rearwardly and into engagement with the teeth314of the planet carrier272, even without pulling the operating cord124in the upward operating pull direction130.

For a discussion of the second embodiment of the control system110employing the second version of the shift arm182, reference is now made to FIGS.12A-12AAA,13A-13AAA and14A-14E. To begin an operational sequence, a pull force upon the operating cord124causes the pulley184to rotate about the second end cap shaft238. However, pulling the operating cord124downward to the right or left determines which direction the shift arm182will pivot and whether the pawl tooth307will engage or not engage the teeth314of the planet carrier272. When a user pulls on the pull cord, the operating cord124is unwound from the cord spool190, which turns the cord spool in a clockwise direction. The operating cord124feeds off the cord spool190to pass over the pulley184between the first cord barrier wall298and the pulley184and down along the cord engagement surface510of the shift arm182.

As can be understood fromFIGS. 3,12A-12AAA and14A-14C, when the operating cord124is displaced downwardly and to the left (i.e., in the downward operating pull direction132), the operating cord124engages the oblique section510″ of the first cord engagement surface510on the boss arm504. This causes the shift arm182to pivot clockwise (as viewed inFIG. 12A) about the third end cap shaft239such that the operating cord124ends up residing against the first cord engagement surface510near or on the tip512of the boss arm504. In one embodiment, as depicted in FIGS.12AA and12AAA, the operating cord124will end up residing against the first cord engagement surface510on the tip512of the boss504near the left planar vertical side of the shift arm182. As a result of the operating cord124engaging the first cord engagement surface510near or on the tip512of the boss504, the pawl tooth307does not engage the teeth314on the planet carrier272, as depicted inFIG. 12A.

As can be understood fromFIG. 12A, the mass of the block portion502, which is offset from the axis of the cylindrical hole508, causes the shift arm182to rotate counterclockwise about said axis as viewed inFIG. 13A. As a result, the pawl tooth307is biased rearwardly and into engagement with the teeth314of the planet carrier272when the operating cord124is not displaced to the left (i.e., in the upward operating pull direction130). Thus, as can be understood fromFIGS. 2,13A-13AAA and14A-14C, when the operating cord124is displaced downwardly and to the right (i.e., in the upward operating pull direction130), the bias causes the shift arm182to pivot counterclockwise about the third end cap shaft239until the parallel section510′ of the first cord engagement surface510on boss arm504encounters the operating cord124and the pawl tooth307is in engagement with the teeth314on the planet carrier272, as depicted inFIG. 13A.

e. Axle Arrangements for Shift Arm and Pulley

As shown in FIG.9AAA, in one version of the second embodiment of the control mechanism110, the third end cap shaft239includes a cylindrical hole extending along the axis of the shaft239. Said cylindrical hole receives a pin530extending from the cord guide arm180to provide outboard support for the third end cap shaft239.

As indicated in FIG.9AAAA, in one version of the second embodiment of the control mechanism110, the cylindrical spacer294includes a cylindrical hole extending along the axis of the spacer294. Said cylindrical hole receives the second end cap shaft238. As a result, the spacer294is able to provide outboard support for the shaft238.

f. Parked Position

As discussed in detail with respect to the first embodiment of the control system110, the second embodiment of the control system110has a cord guide arm180with a horn opening348adapted to matingly receive the clasp126in a “parked” position, as depicted inFIGS. 10B,10BB,13B and13BB. As can be understood from FIGS.10B and10BB, when the clasp126is in the “parked” position for the first version of the shift arm182, the operating cord124abuts against the first cord engagement surface510on or near the tip512of the boss504. As a result, when the pull cord120is not being pulled, the shift arm182is maintained in a position wherein the pawl tooth307does not engage the teeth314of the planet carrier272.

As depicted in FIGS.13B and13BB, when clasp126is in the “parked” position for the second version of the shift arm182, the operating cord124abuts against the oblique section510″ of the first cord engagement surface510on or near the tip512of the boss504. As a result, when the pull cord120is not being pulled, the shift arm182is maintained in a position wherein the pawl tooth307does not engage the teeth314of the planet carrier272.

As discussed in detail with respect to the first embodiment of the control system110, as the operating cord124travels laterally relative to the shift arm182, the position of the operating cord relative to cord engagement surface(s)510,520determines whether the shift arm182pivots to engage or disengage with the transmission176. The position of the operating cord124relative to the cord engagement surface(s)510,520is determined by the pull direction in which the user is placing force on the pull cord and operating cord.

When the pull cord120is not being pulled and the releasable clasp126is in the parked position depicted inFIGS. 10B,13B and7F, the flared opening348is configured to urge the operating cord124to directly overlay the first cord engagement surface510of the boss308on or near the extreme tip312of the boss308, as shown inFIGS. 10B,10BB,13B,13BB. When the pull cord120is being pulled, the flared opening348of the cord guide arm180urges the user to pull on the pull cord and operating cord in either the upward operating pull direction130or the downward operating pull direction132, as shown inFIGS. 2 and 3.

With respect to the first version of the second embodiment, as depicted inFIGS. 9A and 10A, if the pull direction is in the upward operating pull direction130(seeFIG. 2), the operating cord124moves from the parked position and contacts the second cord engagement surface520of the shift arm182as discussed above and shown inFIGS. 10A,10AA and10AAA. With respect to the second version of the second embodiment, as depicted inFIGS. 12A and 13A, if the pull direction is in the downward operating pull direction132(seeFIG. 3), the natural bias of the shift arm configuration causes the shift arm182to pivot counterclockwise until the parallel section510′ of the first cord engagement surface510encounters the operating cord124as discussed above and shown inFIGS. 13A,13AA and13AAA. However, with respect to both the first and second version of the second embodiment, as shown inFIGS. 9A,9AA,10B,10BB,12A,12AA,13B and13BB, if the pull direction is in the downward operating pull direction132(seeFIG. 3), the operating cord124remains in contact with the first cord engagement surface309of the boss because the parked position already had the operating cord124in contact with the tip of the boss309.

It will be appreciated from the above noted description of various arrangements and embodiments of the present invention that a control system for a covering for an architectural opening has been described, which includes an input assembly, a transmission, and an output assembly. The control system can be formed in various ways and operated in various manners depending upon whether covering is to be rolled up along the front or rear side of the head roller. It will be appreciated that the features described in connection with each arrangement and embodiment of the invention are interchangeable to some degree so that many variations beyond those specifically described are possible. For example, the control system can be assembled and supported by various portions of the head rail assembly, such as an end cap, or the control system can be disengaged from the head rail assembly.

Although various embodiments of this invention have been described above with a certain degree of particularity or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to those disclosed embodiments without departing from the spirit or scope of this invention. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative only of particular embodiments, and not limiting. Changes in detail or structure may be made without departing from the basic elements of the invention as defined in the following claims.