Patent Description:
The subject matter disclosed herein relates generally to a position sensing assembly for a tensioning system.

Articles of footwear generally include two primary elements: an upper and a sole structure. The upper can include one or more elements that are configured to fit around and receive a foot. In some embodiments, the upper can form structure that extends over instep and toe areas of the foot, along medial and lateral sides of the foot, and around a heel area of the foot. The upper may also incorporate a securement system, such as a shoelace, straps, or other members, that can be used to adjust the fit of the footwear. The securement system can also permit entry and removal of the foot from the void within the upper.

<CIT> describes a tensioning system for articles of footwear and articles of apparel. The tensioning system includes a tensioning member that is tightened or loosened using a motorized tensioning device for winding and unwinding the tensioning member on a spool. The motorized tensioning device includes a torque transmitting system that allows for incremental tightening, incremental loosening and full loosening of the tensioning member.

An article of footwear according to the claimed invention is defined in claim <NUM>. Dependent claims <NUM>-<NUM> define particular embodiments of the article of footwear according to the claimed invention. Example methods and systems are directed to a position sensing assembly for a tensioning system. Examples merely typify possible variations. Unless explicitly stated otherwise, components and functions are optional and may be combined or subdivided, and operations may vary in sequence or be combined or subdivided. In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of example embodiments. It will be evident to one skilled in the art, however, that the present subject matter may be practiced without each or all of these specific details.

Articles of footwear have conventionally utilized lacing mechanisms that involve manual manipulation of laces or other mechanisms, e.g., manually tying the laces, to secure the article of footwear to a foot of a wearer. However, alternative mechanisms have been developed that provide for the tightening of laces, cables, and the like utilizing motors, transmissions, and reels. Such motors, transmissions, and reels may preferably tighten and loosen the laces within desired parameters, e.g., to provide for a desired tightness when the article of footwear is being worn and a desired looseness when the article of footwear is off of the foot or being removed. Too loose or tight may provide for discomfort while being worn.

However, a motor and/or motor controller does not necessarily know what state the motor is in vis-à-vis the lace. For instance, if the motor controller resets or otherwise enters an indeterminate state, the motor may seek to tighten or loosen the lace beyond the comfort level of the wearer under the circumstances. A motor or motor controller would not inherently be possessed of a system that provides a physical or optical brake to cause the motor to tighten and loosen the lace within desired parameters.

An article of footwear has been developed which includes an motorized lacing system, including a tensioning system. The tensioning system utilizes an indicator tab mounted on a lead screw secured to a reel member for the lace. The position of the indicator tab along the lead screw indicates the state of the lace on the reel, with one position indicating that the lace is taut and another position indicating that the lace is loose. An optical sensing unit detects the position of the indicator tab. Because the indicator tab is not reliant on the state of the motor, the indicator tab may consistently provide for the actual state of the lace on the reel.

The present embodiments relate to a position sensing assembly for a tensioning system designed to provide tension to a lace, cord, or other type of strand. For example, <FIG> and <FIG> illustrate an exemplary embodiment of an article of footwear <NUM> that is configured with a tensioning system <NUM>. The tensioning system may be capable of both tightening and loosening a strand. For example, in the exemplary embodiment shown in the drawings, tensioning system <NUM> may both tighten and loosen a lace <NUM> of a lacing system <NUM>. Details of the mechanism of tightening and loosening lace <NUM> are described below with respect to <FIG>. The tensioning system may include a position sensing assembly that assists in controlling the degree to which the strand is tightened and loosened. As explained in more detail below with respect to <FIG>, such a position sensing assembly may prevent tightening of the strand when the strand is meant to be loosened.

The exemplary embodiment shown in the drawings includes an article of footwear configured with a tensioning system having a position sensing assembly. However, it is understood that the tensioning system and position sensing assembly may be used with articles other than articles of footwear. As discussed in further detail below, a tensioning system may not be limited to footwear and in other examples, not according to the claimed invention, a tensioning system could be used with various kinds of apparel, including clothing, sportswear, sporting equipment and other kinds of apparel. In still other examples, not according to the claimed invention, a tensioning system may be used with braces, such as medical braces.

The Figures show how a position sensing assembly may be incorporated into a tensioning system used with an article of footwear. Thus, the Figures show features of an article of footwear, a tensioning system, and a position sensing assembly. More particularly, <FIG> show the outward appearance of article <NUM>. <FIG> show how the tensioning system <NUM>, including the position sensing assembly, interrelates with article <NUM>. <FIG> provides a detailed view of features of tensioning system <NUM> and lacing system <NUM> both isolated from article <NUM>. <FIG> show details of a reel member <NUM> of tensioning system <NUM>. <FIG> demonstrate how tensioning system <NUM> may tighten and loosen lace <NUM> of tensioning system <NUM> to permit the wearer to tighten an upper <NUM> of article <NUM> around the foot, and to loosen upper <NUM> to facilitate entry and removal of the foot from the interior void (i.e., through throat opening <NUM>). <FIG> show how an optical sensing unit <NUM> detects the position of an indicator tab <NUM> disposed on a lead screw <NUM>. The position of indicator tab <NUM> may indicate the relative tension of lace <NUM>.

In the current embodiment, article of footwear <NUM>, also referred to hereafter simply as article <NUM>, is shown in the form of an athletic shoe. However, in other embodiments, tensioning system <NUM> may be used with any other kind of footwear including, but not limited to: hiking boots, soccer shoes, football shoes, sneakers, running shoes, cross-training shoes, rugby shoes, basketball shoes, baseball shoes as well as other kinds of shoes. In some embodiments article <NUM> may be configured for use with various kinds of non-sports related footwear, including, but not limited to: slippers, sandals, high heeled footwear, loafers as well as any other kinds of footwear.

For reference purposes, article <NUM> may be divided into three general regions: a forefoot region <NUM>, a midfoot region <NUM>, and a heel region <NUM>, as shown in <FIG> and <FIG>. Forefoot region <NUM> generally includes portions of article <NUM> corresponding with the toes and the joints connecting the metatarsals with the phalanges. Midfoot region <NUM> generally includes portions of article <NUM> corresponding with an arch area of the foot. Heel region <NUM> generally corresponds with rear portions of the foot, including the calcaneus bone. Article <NUM> also includes a medial side <NUM> and a lateral side <NUM>, which extend through each of forefoot region <NUM>, midfoot region <NUM>, and heel region <NUM> and correspond with opposite sides of article <NUM>. More particularly, medial side <NUM> corresponds with an inside area of the foot (i.e., the surface that faces toward the other foot), and lateral side <NUM> corresponds with an outside area of the foot (i.e., the surface that faces away from the other foot). Forefoot region <NUM>, midfoot region <NUM>, and heel region <NUM> and medial side <NUM>, lateral side <NUM> are not intended to demarcate precise areas of article <NUM>. Rather, forefoot region <NUM>, midfoot region <NUM>, and heel region <NUM>, and medial side <NUM>, lateral side <NUM> are intended to represent general areas of article <NUM> to aid in the following discussion. In addition to article <NUM>, forefoot region <NUM>, midfoot region <NUM>, and heel region <NUM> and medial side <NUM>, lateral side <NUM> may also be applied to a sole structure, an upper, and individual elements thereof.

For consistency and convenience, directional adjectives are also employed throughout this detailed description corresponding to the illustrated embodiments. The term "lateral" or "lateral direction" as used throughout this detailed description and in the claims refers to a direction extending along a width of a component or element. For example, a lateral direction of article <NUM> may extend between medial side <NUM> and lateral side <NUM>. Additionally, the term "longitudinal" or "longitudinal direction" as used throughout this detailed description and in the claims refers to a direction extending across a length or breadth of an element or component (such as a sole structure or an upper). In some embodiments, a longitudinal direction of article <NUM> may extend from forefoot region <NUM> to heel region <NUM>. It will be understood that each of these directional adjectives may also be applied to individual components of an article of footwear, such as an upper and/or a sole structure. In addition, a vertical direction refers to a direction perpendicular to a horizontal surface defined by the longitudinal direction and the lateral direction. It will be understood that each of these directional adjectives may be applied to various components shown in the embodiments, including article <NUM>, as well as components of a tensioning system <NUM>.

The article of footwear <NUM> includes a sole structure <NUM> and an upper <NUM>. Generally, upper <NUM> may be any type of upper. In particular, upper <NUM> may have any design, shape, size and/or color. For example, in embodiments where article <NUM> is a basketball shoe, upper <NUM> could be a high top upper that is shaped to provide high support on an ankle. In embodiments where article <NUM> is a running shoe, upper <NUM> could be a low top upper.

In some embodiments, sole structure <NUM> may be configured to provide traction for article <NUM>. In addition to providing traction, sole structure <NUM> may attenuate ground reaction forces when compressed between the foot and the ground during walking, running or other ambulatory activities. The configuration of sole structure <NUM> may vary significantly in different embodiments to include a variety of conventional or non-conventional structures. In some cases, the configuration of sole structure <NUM> can be configured according to one or more types of ground surfaces on which sole structure <NUM> may be used. Examples of ground surfaces include, but are not limited to: natural turf, synthetic turf, dirt, as well as other surfaces.

In different embodiments, sole structure <NUM> may include different components. For example, sole structure <NUM> may include an outsole, a midsole, and/or an insole. In addition, in some cases, sole structure <NUM> can include one or more cleat members or traction elements that are configured to increase traction with a ground surface.

In an exemplary embodiment, sole structure <NUM> is secured to upper <NUM> and extends between the foot and the ground when article <NUM> is worn. Upper <NUM> defines an interior void within article <NUM> for receiving and securing a foot relative to sole structure <NUM>. The void is shaped to accommodate the foot and extends along a lateral side of the foot, along a medial side of the foot, over the foot, around the heel, and under the foot. Upper <NUM> may also include a collar that is located in at least heel region <NUM> and forms a throat opening <NUM>. Access to the interior void of upper <NUM> is provided by throat opening <NUM>. More particularly, the foot may be inserted into upper <NUM> through throat opening <NUM>, and the foot may be withdrawn from upper <NUM> through throat opening <NUM>.

In some embodiments, article <NUM> can include a lacing system <NUM>. Lacing system <NUM> extends forward from the collar and throat opening <NUM> in heel region <NUM> over a lacing area <NUM> corresponding to an instep of the foot in midfoot region <NUM> to an area adjacent to forefoot region <NUM>. Lacing area <NUM> extends between a lateral edge <NUM> and a medial edge <NUM> on opposite sides of upper <NUM>. Lacing system <NUM> includes various components configured to secure a foot within upper <NUM> of article <NUM> and, in addition to the components illustrated and described herein, may further include additional or optional components conventionally included with footwear uppers.

In this embodiment, a plurality of strap members <NUM> extends across portions of lacing area <NUM>. Together with tensioning system <NUM> (described in detail below), plurality of strap members <NUM> assist the wearer to modify dimensions of upper <NUM> to accommodate the proportions of the foot. In the exemplary embodiments, plurality of strap members <NUM> extend laterally across lacing area <NUM> between lateral edge <NUM> and medial edge <NUM>. As will be further described below, strap members <NUM> and a lace <NUM> of tensioning system <NUM> permit the wearer to tighten upper <NUM> around the foot, and to loosen upper <NUM> to facilitate entry and removal of the foot from the interior void (i.e., through throat opening <NUM>).

In some embodiments, upper <NUM> includes a tongue <NUM> that extends over a foot of a wearer when disposed within article <NUM> to enhance the comfort of article <NUM>. In this embodiment, tongue <NUM> extends through lacing area <NUM> and can move within an opening between opposite lateral edge <NUM> and medial edge <NUM> of upper <NUM>. In some cases, tongue <NUM> can extend between a lace and/or strap members <NUM> to provide cushioning and disperse tension applied by the lace or strap members <NUM> against a top of a foot of a wearer. With this arrangement, tongue <NUM> can enhance the comfort of article <NUM>.

Some embodiments may include provisions for facilitating the adjustment of an article to a wearer's foot, including tightening and/or loosening the article around the wearer's foot. These provisions include a tensioning system. In some embodiments, a tensioning system may further include other components that include, but are not limited to, a tensioning member, lacing guides, a tensioning assembly, a housing unit, a motor, gears, spools or reels, and/or a power source. Such components may assist in securing, adjusting tension, and providing a customized fit to a wearer's foot. These components and how, in various embodiments, they may secure the article to a wearer's foot, adjust tension, and provide a customized fit will be explained further in detail below.

Referring now to <FIG>, article <NUM> includes an example of a tensioning system <NUM>. Examples of tensioning system <NUM> may include any suitable tensioning system, including incorporating any of the systems disclosed in one or more of Beers et al. , <CIT>, now <CIT>, <CIT>, now<CIT>, <CIT>, now<CIT> and titled "Footwear Having Removable Motorized Adjustment System"; (collectively referred to herein as the "Automatic Lacing cases").

In different embodiments, a tensioning system may include a tensioning member. The term "tensioning member" as used throughout this detailed description and in the claims refers to any component that has a generally elongated shape and high tensile strength. In some cases, a tensioning member could also have a generally low elasticity. Examples of different tensioning members include, but are not limited to: laces, cables, straps and cords. In some cases, tensioning members may be used to fasten and/or tighten an article, including articles of clothing and/or footwear. In other cases, tensioning members may be used to apply tension at a predetermined location for purposes of actuating some components or system.

Tensioning system <NUM> includes a tensioning member in the form of a lace <NUM>. Lace <NUM> is configured to modify the dimensions of the interior void of upper <NUM> and to thereby tighten (or loosen) upper <NUM> around a wearer's foot. In one embodiment, lace <NUM> may be configured to move plurality of strap members <NUM> of lacing system <NUM> so as to bring opposite lateral edge <NUM> and medial edge <NUM> of lacing area <NUM> closer together to tighten upper <NUM>. Similarly, lace <NUM> may also be configured to move plurality of strap members <NUM> in the opposite direction to move lateral edge <NUM> and medial edge <NUM> further apart to loosen upper <NUM>. With this arrangement, lace <NUM> may assist with adjusting tension and/or fit of article <NUM>. As discussed in more detail below, the position sensing assembly may help control how much lace is wound around the shaft.

In some embodiments, lace <NUM> may be connected or joined to strap members <NUM> so that movement of lace <NUM> is communicated to plurality of strap members <NUM>. For example, lace <NUM> may be bonded, stitched, fused, or attached using adhesives or other suitable mechanisms to attach portions of lace <NUM> extending across lacing area <NUM> to each strap member of plurality of strap members <NUM>. With this arrangement, when tension is applied to lace <NUM> via tensioning system <NUM> to tighten or loosen lacing system <NUM>, lace <NUM> can move strap members <NUM> between an open or closed position.

In some embodiments, lace <NUM> may be configured to pass through various lacing guides <NUM> that route lace <NUM> across portions of upper <NUM>. In some cases, ends of lacing guides <NUM> may terminate adjacent to lateral edge <NUM> and medial edge <NUM> of lacing area <NUM>. In some cases, lacing guides <NUM> may provide a similar function to traditional eyelets on uppers. In particular, as lace <NUM> is pulled or tensioned, lacing area <NUM> may generally constrict so that upper <NUM> is tightened around a foot. In one embodiment, lacing guides <NUM> may be routed or located between layers of the material forming upper <NUM>, including any interior layers or linings.

In some embodiments, lacing guides <NUM> may be used to arrange lace <NUM> in a predetermined configuration on upper <NUM> of article <NUM>. Referring to <FIG>, in one embodiment, lace <NUM> is arranged in a serpentine, or alternating-sides, configuration on upper <NUM>. In some other embodiments, lace <NUM> may be arranged, via lacing guides <NUM>, in different configurations.

Tensioning system <NUM> includes a reel member <NUM>. Reel member <NUM> is a component within a tensioning device <NUM> of tensioning system <NUM>. Reel member <NUM> is configured to be rotated around a central axis in opposite directions to wind and/or unwind lace <NUM> and thereby tighten or loosen tensioning system <NUM>.

In an exemplary embodiment, reel member <NUM> is a reel or spool having a shaft <NUM> running along the central axis and a plurality of flanges extending radially outward from shaft <NUM>. The plurality of flanges can have a generally circular or round shape with shaft <NUM> disposed within the center of each flange. The flanges assist with keeping the wound portions of lace <NUM> separated and organized on reel member <NUM> so that lace <NUM> does not become tangled or bird-nested during winding or unwinding when tensioning system <NUM> is tightened or loosened.

In an exemplary embodiment, reel member <NUM> may include a center flange <NUM> located approximately at a midpoint along shaft <NUM> of reel member <NUM>. Center flange <NUM> may include an aperture <NUM> that forms an opening extending between opposite faces of center flange <NUM>. Aperture <NUM> is configured to receive lace <NUM>. As shown in <FIG>, lace <NUM> extends through aperture <NUM> in center flange <NUM> from one side or face of center flange to the other side or opposite face. With this arrangement, portions of lace <NUM> are disposed on opposite sides of center flange <NUM> and lace <NUM> is interconnected to reel member <NUM>.

In one embodiment, reel member <NUM> may include at least three flanges on shaft <NUM>. In this embodiment, reel member <NUM> includes a first end flange <NUM>, center flange <NUM>, and a second end flange <NUM>. Center flange <NUM> is located along shaft <NUM> between first end flange <NUM> and second end flange <NUM>. First end flange <NUM> and second end flange <NUM> are located on shaft <NUM> at opposite ends of reel member <NUM> on either side of center flange <NUM>. First end flange <NUM> and/or second end flange <NUM> may assist with keeping portions of lace <NUM> that are wound on reel member <NUM> from sliding off the ends of reel member <NUM> and may also assist with preventing lace <NUM> from becoming tangled or bird-nested during winding or unwinding when tensioning system <NUM> is tightened or loosened.

In some embodiments, tensioning assembly <NUM> of tensioning system <NUM> may be located within a cavity <NUM> in sole structure <NUM>. Sole structure <NUM> can include an upper surface <NUM> that is disposed adjacent to upper <NUM> on a top of sole structure <NUM>. Upper surface <NUM> may be directly or indirectly attached or joined to upper <NUM> or a component of upper <NUM> to secure sole structure <NUM> and upper <NUM> together. Sole structure <NUM> may also include a lower surface or ground-engaging surface <NUM> that is disposed opposite upper surface <NUM>. Ground-engaging surface <NUM> may be an outsole or other component of sole structure <NUM> that is configured to be in contact with a ground surface when article <NUM> is worn.

In an exemplary embodiment, cavity <NUM> is an opening in sole structure extending from upper surface <NUM> towards lower surface <NUM>. Tensioning assembly <NUM> of tensioning system <NUM> may be inserted within cavity <NUM> from the top of sole structure <NUM>. In an exemplary embodiment, cavity <NUM> has an approximately rectangular shape that corresponds with a rectangular shape of tensioning assembly <NUM>. In addition, cavity <NUM> may be of a similar size and dimension as tensioning assembly <NUM> so that tensioning assembly <NUM> conformably fits within cavity <NUM>. With this arrangement, tensioning assembly <NUM> and related components may be protected from contact with a ground surface by lower surface <NUM> when article <NUM> is worn.

Referring now to <FIG>, an exploded view of article <NUM>, including sole structure <NUM>, upper <NUM>, lacing system <NUM>, and tensioning system <NUM> are illustrated. In this embodiment, the configuration of lace <NUM> through lacing guides <NUM> can be seen alternately extending across lacing area <NUM> of upper <NUM> between medial edge <NUM> on medial side <NUM> and lateral edge <NUM> on lateral side <NUM>.

In addition, to facilitate lace <NUM> being able to tighten and loosen tensioning system <NUM>, ends of lace <NUM> are anchored to upper <NUM> at different locations. As shown in <FIG>, a first anchor <NUM> secures one end of lace <NUM> to upper <NUM> near or adjacent to throat opening <NUM> in heel region <NUM> of upper <NUM> and a second anchor <NUM> secures the opposite end of lace <NUM> to upper <NUM> near or adjacent to forefoot region <NUM>. First anchor <NUM> and second anchor <NUM> may be attached or joined to upper <NUM> may any suitable mechanism, including, but not limited to, knotting, bonding, sewing, adhesives, or other forms of attachment.

<FIG> illustrates an exploded view of an example of components of tensioning system <NUM> including reel member <NUM>, lace <NUM>, and a position sensing assembly. In some embodiments, tensioning system <NUM> can include tensioning assembly <NUM> that is configured to adjust the tension of components of lacing system <NUM>, including lace <NUM> and/or strap members <NUM>, to secure, adjust, and modify the fit of article <NUM> around a wearer's foot. Tensioning assembly <NUM> may be any suitable device for adjusting tension of a tensioning member, such as a lace or strap, and can include any of the devices or mechanisms described in the Automatic Lacing cases described above.

Referring to <FIG>, some components of tensioning assembly <NUM> are shown within a portion of a housing unit <NUM>. In some embodiments, housing unit <NUM> may be shaped so as to optimize the arrangement of components of tensioning assembly <NUM>. In one embodiment, tensioning assembly <NUM> includes housing unit <NUM> that has an approximately rectangular shape. However, it should be understood that the shape and configuration of housing unit <NUM> may be modified in accordance with the type and configuration of tensioning assembly used within tensioning system <NUM>.

In this embodiment, tensioning assembly <NUM> includes reel member <NUM> that is mechanically coupled to a motor <NUM>. In some embodiments, motor <NUM> could include an electric motor. However, in other embodiments, motor <NUM> could comprise any kind of non-electric motor known in the art. Examples of different motors that can be used include, but are not limited to: DC motors (such as permanent-magnet motors, brushed DC motors, brushless DC motors, switched reluctance motors, etc.), AC motors (such as motors with sliding rotors, synchronous electrical motors, asynchronous electrical motors, induction motors, etc.), universal motors, stepper motors, piezoelectric motors, as well as any other kinds of motors known in the art.

Motor <NUM> may further include a crankshaft <NUM> that can be used to drive one or more components of tensioning assembly <NUM>. For example, a gear <NUM> may be mechanically coupled to reel member <NUM> and may be driven by crankshaft <NUM> of motor <NUM>. With this arrangement, reel member <NUM> may be placed in communication with motor <NUM> to be rotated in opposite directions around a central axis.

For purposes of reference, the following detailed description uses the terms "first rotational direction" and "second rotational direction" in describing the rotational directions of one or more components about a central axis. For purposes of convenience, the first rotational direction and the second rotational direction refer to rotational directions about central axis of shaft <NUM> of reel member <NUM> and are generally opposite rotational directions. The first rotational direction may refer to the counterclockwise rotation of a component about the central axis, when viewing the component from the vantage point of a first end <NUM> of shaft <NUM>. The second rotational direction may be then be characterized by the clockwise rotation of a component about the central axis, when viewing the component from the same vantage point.

In some embodiments, tensioning assembly <NUM> may include provisions for powering motor <NUM>, including a power source <NUM>. Power source <NUM> may include a battery and/or control unit (not shown) configured to power and control tensioning assembly <NUM> and motor <NUM>. Power source <NUM> may be any suitable battery of one or more types of battery technologies that could be used to power motor <NUM> and tensioning system <NUM>. One possibly battery technology that could be used is a lithium polymer battery. The battery (or batteries) could be rechargeable or replaceable units packaged as flat, cylindrical, or coin shaped. In addition, batteries could be single cell or cells in series or parallel. Other suitable batteries and/or power sources may be used for power source <NUM>.

In the embodiments shown, motor <NUM>, power source <NUM>, reel member <NUM>, crankshaft <NUM>, and gear <NUM> are all disposed in housing unit <NUM>, along with additional components, such as control unit or other elements, which may function to receive and protect all of these components within tensioning assembly <NUM>. In other embodiments, however, any one or more of these components could be disposed in any other portions of an article, including the upper and/or sole structure.

Housing unit <NUM> includes openings <NUM> that permit lace <NUM> to enter into tensioning assembly <NUM> and engage reel member <NUM>. As discussed above, lace <NUM> extends through aperture <NUM> in center flange <NUM> of reel member <NUM> to interconnect lace <NUM> with reel member <NUM>. When lace <NUM> is disposed through aperture <NUM> of center flange <NUM>, lace <NUM> may include a first lace portion <NUM> located on one side of center flange <NUM> and a second lace portion <NUM> located on the opposite side of center flange <NUM>. Accordingly, openings <NUM> in housing unit <NUM> allow both first lace portion <NUM> and second lace portion <NUM> of lace <NUM> to wind and unwind around reel member <NUM> within the inside of housing unit <NUM> of tensioning assembly <NUM>.

Referring now to <FIG>, an enlarged view of an example of reel member <NUM> is illustrated. In this example, reel member <NUM> has a central axis that extends along a longitudinal length of reel member <NUM> from a first end <NUM> to a second end <NUM>. As described above, reel member <NUM> is configured to rotate about the central axis in a first rotational direction and an opposite second rotational direction to wind or unwind lace <NUM> around portions of shaft <NUM>. In addition, reel member <NUM> may include a screw <NUM> disposed at second end <NUM> that is configured to engage with one or more gear assembly components, including gear <NUM> and/or crankshaft <NUM>, so as to be in communication with motor <NUM>. With this configuration, motor <NUM> may rotate reel member <NUM> about the central axis in the first rotational direction and the second rotational direction.

In some embodiments, reel member <NUM> may include a lead screw <NUM> disposed at first end <NUM>. As discussed in more detail below, lead screw <NUM> may be part of the position sensing assembly.

In some embodiments, portions of shaft <NUM> of reel member <NUM> may be described with reference to the plurality of flanges extending away from shaft <NUM>. For example, a first shaft section <NUM> extends between first end flange <NUM> and center flange <NUM> and a second shaft section <NUM> extends between second end flange <NUM> and center flange <NUM>. Shaft <NUM> may also include a third shaft section <NUM> extending from first end flange <NUM> to first end <NUM> and a fourth shaft section <NUM> extending from second end flange <NUM> to second end <NUM>. In some embodiments, screw <NUM> may be disposed on fourth shaft section <NUM>. In some embodiments, lead screw <NUM> may be disposed on third shaft section <NUM>.

In some embodiments, each of the plurality of flanges has two opposing faces with surfaces that are oriented towards opposite ends of reel member <NUM>. For example, first end flange <NUM> has an outer face <NUM> having a surface oriented towards first end <NUM> of shaft <NUM> and an opposite inner face <NUM> having a surface oriented towards second end <NUM>. Similarly, second end flange <NUM> has an outer face <NUM> having a surface oriented towards second end <NUM> and an opposite inner face <NUM> having a surface oriented towards first end <NUM> of shaft <NUM>. Center flange <NUM> includes a first face <NUM> and an opposite second face <NUM>. First face <NUM> of center flange <NUM> has a surface oriented towards first end <NUM> of shaft <NUM> and facing inner face <NUM> of first end flange <NUM>. Second face <NUM> of center flange <NUM> has a surface oriented towards second end <NUM> of shaft <NUM> and facing inner face <NUM> of second end flange <NUM>.

In an exemplary embodiment, center flange <NUM> includes aperture <NUM>, described above. Aperture <NUM> extends between first face <NUM> and second face <NUM> of center flange <NUM> and provides an opening that allows lace <NUM> to extend between the opposite sides or faces of center flange <NUM>. In some embodiments, center flange <NUM> extends radially outward from shaft <NUM> and aperture <NUM> is located on center flange <NUM> so as to be spaced apart from shaft <NUM>. In this embodiment, aperture <NUM> is located adjacent to a perimeter edge of center flange <NUM>. In different embodiments, the distance between the perimeter edge of center flange <NUM> and the location of aperture <NUM> may vary. For example, the distance may be determined on the basis of revolution rate of tensioning assembly <NUM> and/or motor <NUM> or may be determined on the basis of the desired tension within tensioning system <NUM>.

As shown in <FIG>, when lace <NUM> extends through aperture <NUM> in center flange <NUM>, lace <NUM> can include a first lace portion <NUM> disposed on one side of center flange <NUM> and a second lace portion <NUM> disposed on the opposite side of center flange <NUM>. In this embodiment, first lace portion <NUM> is disposed on the side of center flange <NUM> that corresponds with first face <NUM> and second lace portion <NUM> is disposed on the side of center flange <NUM> that corresponds with second face <NUM>. With this arrangement, lace <NUM> may be interconnected to reel member <NUM>.

As will be further described below, reel member <NUM> is operable to be rotated in the first rotational direction or the second rotational direction to wind or unwind lace <NUM> and thereby tighten or loosen tensioning system <NUM>. For example, motor <NUM> and/or an associated control unit of tensioning system <NUM> can be used to control rotation of reel member <NUM>, including automatic operation and/or based on user inputs. When tensioning system <NUM> is tightened, reel member <NUM> rotates while lace <NUM> is interconnected to center flange <NUM> at aperture <NUM>. This rotation causes first lace portion <NUM> and second lace portion <NUM> to be wound onto portions of shaft <NUM> on opposite sides of center flange <NUM>. Specifically, first lace portion <NUM> is wound onto first shaft section <NUM> and second lace portion <NUM> is wound onto second shaft section <NUM>.

In this embodiment, first face <NUM> of center flange <NUM> and inner face <NUM> of first end flange <NUM> serve as boundaries or walls on the ends of first shaft section <NUM> to assist with keeping first lace portion <NUM> located on first shaft section <NUM> of reel member <NUM> during winding and unwinding of lace <NUM> with tensioning assembly <NUM>. In a similar manner, second face <NUM> of center flange <NUM> and inner face <NUM> of second end flange <NUM> serve as boundaries or walls on the ends of second shaft section <NUM> to assist with keeping second lace portion <NUM> located on second shaft section <NUM> of reel member <NUM> during winding and unwinding of lace <NUM> with tensioning assembly <NUM>. With this arrangement, lace <NUM>, including first lace portion <NUM> and second lace portion <NUM>, may be prevented from getting tangled or bird-nested during operation of tensioning system <NUM>.

<FIG> illustrates a cross-sectional view of reel member <NUM> and shows the interconnection of lace <NUM> with reel member <NUM> within tensioning system <NUM>. In this embodiment, first lace portion <NUM> of lace <NUM> extends through aperture <NUM> in the surface of first face <NUM> of center flange <NUM> and second lace portion <NUM> of lace <NUM> outwards from aperture <NUM> in the surface of second face <NUM> on the opposite side of center flange <NUM>. With this arrangement, lace <NUM> is interconnected to reel member <NUM> via aperture <NUM> in center flange <NUM> such that rotation of reel member <NUM> about the central axis will cause first lace portion <NUM> and second lace portion <NUM> to respectively wind about first shaft section <NUM> and second shaft section <NUM>.

In some embodiments, tensioning system <NUM> is operable to be controlled between at least a tightened condition and a loosened condition. In different embodiments, however, it should be understood that tensioning system <NUM> may be controlled to be placed into various degrees or amounts of tension that range between a fully tightened and a fully loosened condition. In addition, tensioning system <NUM> may include predetermined tension settings or user-defined tension settings. The position sensing assembly may be used to determine whether the tensioning system <NUM> is in the tightened condition, a loosened condition, or a condition that is in between the tightened condition and the loosened condition. <FIG> and <FIG> illustrate examples of tensioning system <NUM> being operated between a loosened condition (<FIG>) and a tightened condition (<FIG>). It should be understood that the method of tightening and/or loosening tensioning system <NUM> using tensioning assembly <NUM> may be performed in reverse order to loosen tensioning system <NUM> from the tightened condition to the loosened condition. <FIG> illustrate examples of a position sensing assembly using optical sensing unit <NUM> to sense a position of indicator tab <NUM>. The position of indicator tab <NUM> may indicate the condition of tensioning system <NUM>.

Referring now to <FIG>, an example of tensioning system <NUM> in a loosened condition is illustrated. In this embodiment, a foot <NUM> of a wearer is inserted into article <NUM> with tensioning system <NUM> in an initially loosened condition. In the loosened condition, lacing system <NUM> and plurality of strap members <NUM> are unfastened or in an open position to allow entrance of foot <NUM> within the interior void of upper <NUM>. Lace <NUM> is connected to strap members <NUM> of lacing system <NUM> and is also interconnected to reel member <NUM> of tensioning assembly <NUM> by being disposed through aperture <NUM> in central flange <NUM> of reel member <NUM>. With this arrangement, winding of lace <NUM> around portions of reel member <NUM> will cause tension in lace <NUM> to pull plurality of strap members <NUM> of lacing system <NUM> to a closed position and tighten upper <NUM> around foot <NUM> when tensioning system <NUM> is in the tightened condition.

<FIG> illustrates an example of tensioning system <NUM> in a tightened condition. In this embodiment, tensioning device <NUM> rotates reel member <NUM> in the first rotational direction (e.g., counterclockwise) about the central axis to apply tension to lace <NUM> and tighten tensioning system <NUM>. The interconnection of lace <NUM> to central flange <NUM> through aperture <NUM> causes first lace portion <NUM> to wind around first shaft section <NUM> and second lace portion <NUM> to wind around second shaft section <NUM> when reel member <NUM> is rotated in the first rotational direction. The tension applied to lace <NUM> and transmitted from lace <NUM> to plurality of strap members <NUM> moves lacing system <NUM> to a closed position to secure upper <NUM> around foot <NUM> when tensioning system <NUM> is in the tightened condition.

Similarly, rotation of reel member <NUM> can be made in the opposite second rotational direction to unwind lace <NUM> from portions of shaft <NUM> to return tensioning system <NUM> to the loosened condition, as shown in <FIG> above. In addition, in some embodiments, rotation of reel member <NUM> in the second rotational direction may be performed by motor <NUM>, by a user manually pulling on lace <NUM>, and/or strap members <NUM>, or both.

In an exemplary embodiment, rotation of reel member <NUM> in either or both of the first rotational direction and the second rotational direction will cause lace <NUM> to wind or unwind substantially equally around portions of shaft <NUM> of reel member <NUM>. That is, the amount of first lace portion <NUM> wound on first shaft section <NUM> and the amount of second lace portion <NUM> wound on second shaft section <NUM> will be approximately equal on opposite sides of central flange <NUM> when tensioning system <NUM> is in the tightened condition. Similarly, during unwinding of lace <NUM> from reel member <NUM>, approximately equal portions of lace <NUM> are unwound from opposite sides of center flange <NUM> when tensioning system <NUM> is placed in the loosened condition from the tightened condition. That is, the amount of first lace portion <NUM> unwound or spooled out from first shaft section <NUM> and the amount of second lace portion <NUM> unwound or spooled out from second shaft section <NUM> will be approximately equal.

To control how much lace is wound around the shaft, a position sensing assembly is included with the tensioning system. Referring to <FIG> and <FIG>, tensioning system <NUM> is shown as having a position sensing assembly. The position sensing assembly includes a shaft. For example, the position sensing assembly may include third shaft section <NUM>. The shaft of the position sensing assembly may be configured to rotate about the same rotational axis as the rest of shaft <NUM>. In some embodiments, the shaft may be integral with the rest of shaft <NUM>. In other embodiments, the shaft may be a separate part connected to shaft <NUM> and/or first end flange <NUM>. The shaft of the position sensing assembly is a lead screw. For example, the position sensing assembly shown in <FIG> includes lead screw <NUM>.

The position sensing assembly includes an indicator tab. For example, the position sensing assembly may include indicator tab <NUM>. The position sensing assembly includes an optical sensing unit <NUM>.

In some embodiments, indicator tab <NUM> may have a passage <NUM> configured to receive lead screw <NUM>. Passage <NUM> may further include interior threads that may engage with threads of lead screw <NUM>. The exterior of indicator tab <NUM> may have any geometric shape allowing first optical sensor <NUM> and second optical sensor <NUM> to detect indicator tab <NUM> in the manner described below. For example, in some embodiments, as shown in <FIG> and <FIG>, the exterior of indicator tab <NUM> may have a rectangular shape. In another example, in other embodiments, the exterior of the indicator tab may have an arcuate shape, a triangular shape, or a square shape.

In some embodiments, indicator tab <NUM> may include a first portion <NUM> that extends away from the portion of indicator tab <NUM> including passage <NUM>. As shown in <FIG>, first portion <NUM> may have a height H1. Height H1 may be selected to extend beyond lead screw <NUM> a distance sufficient for optical sensing unit <NUM> to detect indicator tab <NUM> without interference from lead screw <NUM>. The portion of indicator tab <NUM> detected by optical sensing unit <NUM> is a detectable area. In some embodiments, the portion of indicator tab <NUM> that includes passage <NUM> may be a first unit and first portion <NUM> may be a second unit attached to the first unit. For example, in some embodiments, the portion of the indicator tab that includes a passage may be a nut and the first portion of the indicator tab may be a flag, tab, or other object extending from the nut. In some embodiments, the indicator tab may be a nut.

Indicator tab <NUM> may include a second portion <NUM> that extends away from the portion of indicator tab <NUM> including threaded passage <NUM>. As shown in <FIG>, second portion <NUM> may have a height H2. For reasons discussed in more detail below, height H2 may be selected to extend beyond lead screw <NUM> a distance sufficient for a surface <NUM> of indicator tab <NUM> to contact bottom surface <NUM> of housing unit <NUM>.

In some embodiments, second portion <NUM> may be both the detectable area and the portion contacting a surface of housing unit <NUM>. In other words, optical sensing unit <NUM> may be positioned to detect second portion <NUM> instead of first portion <NUM>. For example, optical sensing unit may be positioned closer to surface <NUM> than where optical sensing unit <NUM> is shown in <FIG>. In a more specific example, optical sensing unit may contact surface <NUM>. In embodiments in which second portion <NUM> is the detectable area, height H1 may be selected to extend less than a distance sufficient for optical sensing unit <NUM> to detect indicator tab <NUM> without interference from lead screw <NUM>. Additionally, in such embodiments, height H2 may be selected to extend beyond lead screw <NUM> a distance sufficient for optical sensing unit <NUM> to detect indicator tab <NUM> without interference from lead screw <NUM>.

Optical sensing unit <NUM> may be any sort of optical sensing unit capable of detecting the presence of an object in two different positions, and distinguishing between when the object is in the first position and when the object is in the second position. Optical sensing unit <NUM> includes a first optical sensor <NUM> capable of detecting the first position (<FIG>) and a second optical sensor <NUM> capable of detecting the second position (<FIG>). First optical sensor <NUM> and second optical sensor <NUM> are capable of detecting the presence of an object. More specifically, first optical sensor <NUM> and second optical sensor <NUM> are capable of detecting the presence of indicator tab <NUM>. First optical sensor <NUM> is positioned and oriented such that first optical sensor may detect the presence of indicator tab <NUM> in the first position. As shown in <FIG>, first optical sensor <NUM> is vertically aligned with the indicator tab <NUM> such that first optical sensor <NUM> can detect the detectable area of indicator tab <NUM> when indicator tab <NUM> is in the first position. Second optical sensor <NUM> is positioned and oriented such that second optical sensor <NUM> may detect the presence of indicator tab <NUM> in the second position. Second optical sensor <NUM> is vertically aligned with the indicator tab <NUM> such that second optical sensor <NUM> can detect the detectable area of indicator tab <NUM> when indicator tab <NUM> is in the second position. In some embodiments, as shown in <FIG>, first optical sensor <NUM> may be disposed on the same face of optical sensing unit <NUM> on which second optical sensor <NUM> is disposed. In such an arrangement, first optical sensor <NUM> and second optical sensor <NUM> may be disposed side-by-side. For example, in some embodiments, first optical sensor <NUM> may be vertically aligned with second optical sensor <NUM>. The spacing between first optical sensor <NUM> and second optical sensor <NUM> is discussed below along with the operation optical sensing unit <NUM>. Optical sensing unit <NUM> may be configured to distinguish between when the object is in the first position and when the object is in the second position. For example, optical sensing unit <NUM> may be connected with a processor programmed to distinguish between when the object is in the first position and when the object is in the second position.

An example of the operation of the position sensing assembly is now described. Because third shaft section <NUM> may rotate about the same rotational axis as the rest of shaft <NUM>, third shaft section <NUM> may rotate the same number of times shaft <NUM> rotates. Accordingly, the rotation of third shaft section <NUM> corresponds with the rotation of shaft <NUM>. As third shaft section <NUM> rotates, contact between a surface <NUM> of housing unit <NUM> and bottom surface <NUM> of indicator tab <NUM> may inhibit indicator tab <NUM> from rotating in conjunction with shaft <NUM>. When third shaft section <NUM> rotates, the threaded engagement between indicator tab <NUM> and screw <NUM>, along with the contact between a surface <NUM> of housing unit <NUM> and bottom surface <NUM> of indicator tab <NUM>, causes indicator tab <NUM> to travel linearly along screw <NUM> in both a first linear direction and a second linear direction that is opposite the first linear direction. The first linear direction may be directed away from both center flange <NUM> and first end flange <NUM>. The second linear direction may be directed toward both center flange <NUM> and first end flange <NUM>. Indicator tab <NUM> may travel linearly along screw <NUM> between a first position (<FIG>) and a second position (<FIG>). Indicator tab <NUM> may travel linearly along screw <NUM> in the first linear direction to the first position (<FIG>). Indicator tab <NUM> travel linearly along screw <NUM> in the second linear direction toward the second position (<FIG>).

<FIG> shows indicator tab <NUM> in the first position. In the first position, indicator tab <NUM> is positioned as far as indicator tab <NUM> may go in the first linear direction. In some embodiments, a surface <NUM> of housing unit <NUM> may prevent indicator tab <NUM> from moving further in the first linear direction past end <NUM> of shaft <NUM>.

<FIG> shows indicator tab <NUM> in the second position. In the second position, indicator tab <NUM> is positioned as far as indicator tab <NUM> may go in the second linear direction. In some embodiments, the lack of threads and/or the presence of a larger diameter at bulged region <NUM> may prevent indicator tab <NUM> from moving further in the second linear direction. While the exemplary embodiment shows bulged region <NUM> of third shaft section <NUM>, it is understood that a nut or other object may be disposed where bulged region is located to prevent indicator tab <NUM> from moving further in the second linear direction. In some embodiments, bulged region <NUM> may be eliminated and first end flange <NUM> may prevent indicator tab <NUM> from moving further in the second linear direction.

The diameter of third shaft section <NUM>, the length of third shaft section, and/or the threading (e.g., the angle of threads, pitch of threads, and/or number of threads per unit of distance) may be selected to correspond with the loosened and tightened condition of tensioning system <NUM>. Accordingly, in some embodiments, as shown in <FIG>, the first position of indicator tab <NUM> may correspond with the fully loosened condition of tensioning system <NUM> shown in <FIG>. Additionally, in some embodiments, as shown in <FIG>, the second position of indicator tab <NUM> may correspond with the fully tightened condition of tensioning system <NUM> shown in <FIG>. Thus, the position of indicator tab <NUM> along screw <NUM> may indicate the relative tension of lace <NUM>. While <FIG> show the most extreme positions of indicator tab <NUM>, it is understood that indicator tab <NUM> may have positions between the first position and the second position that indicate different degrees of tension of the tensioning system <NUM>.

<FIG> show the operation of optical sensing unit <NUM>, including how optical sensing unit <NUM> detects the position of an indicator tab <NUM> disposed on lead screw <NUM>. When indicator tab <NUM> is disposed in the first position, first optical sensor <NUM> may detect the presence of indicator tab <NUM>, and second optical sensor <NUM> may not detect the presence of indicator tab <NUM>. In other words, the condition of first optical sensor <NUM> detecting the presence of indicator tab <NUM> and second optical sensor <NUM> detecting the absence of indicator tab <NUM> may indicate that indicator tab <NUM> is in the first position and tensioning system <NUM> is in the loosened condition.

In some embodiments, when indicator tab <NUM> is disposed in the second position, first optical sensor <NUM> may not detect the presence of indicator tab <NUM>, and second optical sensor <NUM> may detect the presence of indicator tab <NUM>. In other words, the condition of first optical sensor <NUM> detecting the absence of indicator tab <NUM>, and second optical sensor <NUM> detecting the presence of indicator tab <NUM>, may indicate that indicator tab <NUM> is in the second position and tensioning system <NUM> is in the tightened condition. In some embodiments, a width W of indicator tab <NUM> and/or the distance between first optical sensor <NUM> and second optical sensor <NUM> may be selected to cause the above-mentioned detection of the first position and the second position. In some embodiments, width W of indicator tab <NUM> and/or the distance between first optical sensor <NUM> and second optical sensor <NUM> may be selected to cause first optical sensor <NUM> and second optical sensor <NUM> to be incapable of detecting the presence of indicator tab <NUM> at the same time. In some embodiments, first optical sensor <NUM> may be positioned or directed, with respect to indicator tab <NUM>, such that indicator tab <NUM> is out of the line of sight of first optical sensor <NUM> when indicator tab <NUM> is in the second position. In some embodiments, second optical sensor <NUM> may be positioned or directed, with respect to indicator tab <NUM>, such that indicator tab <NUM> is out of the line of sight of second optical sensor <NUM> when indicator tab <NUM> is in the first position.

In other embodiments, width W of indicator tab <NUM> and/or the distance between first optical sensor <NUM> and second optical sensor <NUM> may be selected to cause first optical sensor <NUM> and second optical sensor <NUM> to be capable of detecting the presence of indicator tab <NUM> at the same time. In such an embodiment, the condition of first optical sensor <NUM> and second optical sensor <NUM> both detecting the presence of indicator tab <NUM> at the same time may indicate that indicator tab <NUM> is in a position that is located between the first position and the second position, and thus, tensioning system <NUM> is in a condition that is in between the tightened condition and the loosened condition. In some embodiments, first optical sensor <NUM> and second optical sensor <NUM> may each be pivoted to direct the respective sensor toward a particular direction.

By sensing the first position of indicator tab <NUM>, position sensing assembly may detect a condition that indicates when a lace is, and is not, wrapped about the shaft. Detecting this condition may assist in determining when rotation of shaft <NUM> should cease. Stopping shaft <NUM> from rotating when shaft <NUM> is absent of any lace may prevent lace <NUM> from beginning to wind around shaft <NUM> in a rotational direction that is opposite the rotational direction in which lace <NUM> was previously wound. Halting rotation of shaft <NUM> when shaft <NUM> is absent of any lace may leave the lace is the loosest condition. In other words, less lace on shaft <NUM> means more lace positioned between medial edge <NUM> and lateral edge <NUM> of upper <NUM>. As a result, medial edge <NUM> and lateral edge <NUM> may be spaced further apart as lace <NUM> is removed from shaft <NUM>. The more lace that is on the shaft <NUM>, the less the percentage of lace <NUM> that is positioned between medial edge <NUM> and the lateral edge <NUM>. As a result, medial edge <NUM> and lateral edge <NUM> may be closer together as lace <NUM> is wound around shaft <NUM>. In one embodiment, discussed in more detail above, lace <NUM> may be configured to move plurality of strap members <NUM> of lacing system <NUM> so as to bring opposite lateral edge <NUM> and medial edge <NUM> of lacing area <NUM> closer together to tighten upper <NUM>.

<FIG> is a flowchart for making a tensioning system and/or an article of footwear, in an example embodiment. While the flowchart may be utilized to make the tensioning system <NUM> and/or the article of footwear <NUM>, as well as any suitable system, article, or device.

At <NUM>, a lead screw is extended from a second end of a shaft a reel member, the reel member configured to rotate about a central axis, the shaft having a first end opposite the second end, the lead screw configured to rotate about the central axis. The lead screw includes a first set of threads and configured to rotate about the central axis and an indicator tab mounted on the lead screw such that the indicator tab is moveable linearly along the lead screw from a first position on the lead screw to a second position on the lead screw as the lead screw rotates about the central axis. In an example, extending the indicator tab comprises engaging a second set of threads of a passage extending through the indicator tab with the first set of threads of the lead screw and positioning a first portion of the indicator tab extending away from the passage and to be detected by the first optical sensor when the indicator tab is in the first position and by the second optical detector when the indicator tab is in the second position.

In an example, extending the indicator tab includes extending a second portion of the indicator tab away from the passage in a direction opposite the first portion. In an example, extending the second portion includes contacting the second portion with a surface of the housing unit such that the surface inhibits the indicator tab from rotating in conjunction with rotation of the lead screw.

At <NUM>, an optical sensing unit is disposed adjacent the lead screw and configured to detect a position of the indicator tab at one of the first position and the second position. In an example, wherein the reel member is configured to tighten the tensioning system by winding a lace around the shaft based, at least in part, on the position of the indicator tab as detected by the optical sensing unit. In an example, the lead screw, the reel member, the indicator tab, and the optical sensing unit form a tensioning system.

At <NUM>, disposing the optical sensing unit further comprises positioning a first optical sensor to detect the indicator tab in the first position. In an example, disposing the optical sensing unit comprises positioning the first optical sensor to not detect the indicator tab in the second position. In an example, positioning the first optical sensor includes positioning the first optical sensor such that the first optical sensor can detect the second portion when the indicator tab is in the first position.

At <NUM>, disposing the optical sensing unit further comprises positioning a second optical sensor to detect the indicator tab in the second position. In an example, disposing the optical sensing unit comprises positioning the second optical sensor to not detect the indicator tab in the first position.

At <NUM>, an article of footwear is formed by securing an upper to a sole structure and securing the tensioning system with respect to at least one of the upper and the sole structure.

Claim 1:
An article of footwear, comprising:
an upper;
a sole structure attached to the upper; and
a tensioning system (<NUM>) disposed within the sole structure, the tensioning system (<NUM>) including:
a reel member (<NUM>) configured to rotate about a central axis, the reel member (<NUM>) having a shaft extending from a first end (<NUM>) to a second end (<NUM>) opposite the first end (<NUM>);
characterized in that the tensioning system further comprises a lead screw (<NUM>) extending from the second end (<NUM>) of the shaft and having a first set of threads, wherein the lead screw (<NUM>) is configured to rotate about the central axis;
an indicator tab (<NUM>) mounted on the lead screw (<NUM>) such that the indicator tab (<NUM>) is moveable linearly along the lead screw (<NUM>) from a first position on the lead screw (<NUM>) to a second position on the lead screw (<NUM>) as the lead screw (<NUM>) rotates about the central axis; and
an optical sensing unit (<NUM>) disposed adjacent the lead screw (<NUM>);
wherein the reel member (<NUM>) is configured to tighten the tensioning system (<NUM>) by winding a lace (<NUM>) around the shaft based, at least in part, on the position of the indicator tab as detected by the optical sensing unit;
wherein the optical sensing unit (<NUM>) comprises a first optical sensor (<NUM>) and a second optical sensor (<NUM>);
wherein the first optical sensor (<NUM>) is vertically aligned with the indicator tab (<NUM>) such that the first optical sensor (<NUM>) can detect the indicator tab (<NUM>) when the indicator tab (<NUM>) is in the first position; and
wherein the second optical sensor (<NUM>) is vertically aligned with the indicator tab (<NUM>) such that the second optical sensor (<NUM>) can detect the indicator tab (<NUM>) when the indicator tab (<NUM>) is in the second position.