Patent Publication Number: US-11643872-B2

Title: Operating system for a covering for an architectural opening

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of pending U.S. patent application Ser. No. 15/856,121, filed Dec. 28, 2017, entitled “Operating System For a Covering For an Architectural Opening”, which is a continuation application of U.S. patent application Ser. No. 14/766,043, filed Aug. 5, 2015, now U.S. Pat. No. 9,890,588, entitled “Operating System For a Covering For an Architectural Opening”, which application is the national stage application of International Patent Application No. PCT/US2013/030176, filed Mar. 11, 2013, entitled “Operating System For a Covering For an Architectural Opening’, which are hereby incorporated by reference herein in their entirety for all purposes. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to coverings for architectural openings, and more particularly to methods and apparatus for operating a covering for an architectural opening. 
     BACKGROUND 
     Coverings for architectural openings, such as windows, doors, archways, and the like, have taken numerous forms for many years. Some conventional coverings include a retractable shade portion that is movable between an extended position and a retracted position. In the extended position, the shade portion of the covering may be positioned across the opening. In the retracted position, the shade portion of the covering may be positioned adjacent one or more sides of the opening. 
     To move the shade portion of the covering between the extended and retracted positions, some coverings include a roller rotatably associated with a fixed end rail of the covering. Rotation of the roller in a first direction retracts the shade portion of the covering to a position adjacent one or more sides of the opening, and rotation of the roller in a second, opposite direction extends the shade portion across the opening. The roller generally extends between two opposing end caps, and the shade portion of the covering may wrap around the roller or be gathered or stacked adjacent to the roller. For example, some retractable coverings include a flexible shade or shade material suspended from a roller. The shade material can either be wrapped about the roller to retract the shade material or unwrapped from the roller to extend the shade material. As another example, some retractable coverings, such as Venetian blinds, include a plurality of slats that are raised or lowered as lift cords are wrapped about or unwrapped from a rotatable roller. Regardless of the form of the retractable covering, rotation of the roller generally causes movement of the shade portion of the covering. To actuate movement of the roller, and thus the shade portion of the covering, an operating system may be operably coupled to the roller. 
     SUMMARY 
     Examples of the disclosure may include a covering for an architectural opening. In one example, the covering may include a roller, a shade, and an operating system. The roller may be rotatable about a longitudinal axis in an extension direction and a retraction direction. The shade may be associated with the roller. The operating system may be operably associated with the roller. The operating system may include a base, a drive mechanism associated with the base to provide an input torque, a transmission associated with the drive mechanism to selectively transmit the input torque to the roller, and an actuator arm operably associated with the base to indirectly set a rotation direction of the roller. The actuator arm may be movable about a first axis that is generally transverse to the longitudinal axis of the roller. 
     The covering may further include an engagement arm operably associated with the base and movable about a second axis. The second axis may be generally parallel to the longitudinal axis of the roller. The second axis may be generally transverse to the first axis. The engagement arm may selectively engage the transmission to set the rotation direction of the roller. The transmission may include a ring gear, and the engagement arm may selectively engage the ring gear to set the rotation direction of the roller. The operating system may further include a biasing element configured to bias the engagement arm into engagement with the transmission. To set the rotation direction of the roller to the extension direction, the actuator arm may contact the engagement arm to disengage the engagement arm from the transmission. The engagement arm may include a detent configured to retain the actuator arm in a position associated with the extension direction. The drive mechanism may include a single operating element. The single operating element may be operably associated with the actuator arm so that select movement of the single operating element moves the actuator arm. The shade may be wrappable about the roller. The drive mechanism may be motorized. When the actuator arm indirectly sets the rotation direction of the roller to the extension direction, the shade may extend automatically under the influence of gravity without further action by an operator. 
     In another example, the covering may include a rotatable roller, a shade associated with the roller, and an operating system operably associated with the roller. The operating system may include a base, a drive mechanism associated with the base to provide an input torque, a transmission associated with the drive mechanism to selectively transmit the input torque to the roller, an engagement arm movably associated with the base and selectively engageable with the transmission to set a rotation direction of the roller, and an actuator arm operably associated with the base and the engagement arm to move the engagement arm relative to the transmission. The actuator arm may be movable about a first axis, and the engagement arm may be movable about a second axis that is generally transverse to the first axis. 
     The roller may be rotatable about a longitudinal axis. The first axis may be generally transverse to the longitudinal axis of the roller. The second axis may be generally parallel to the longitudinal axis of the roller. The actuator arm may be positioned relative to the transmission so that the actuator arm does not engage the transmission. When the engagement arm sets the rotation direction of the roller to an extension direction, the shade may extend automatically under the influence of gravity without further action by an operator. 
     In another example, an operating system for an architectural covering is provided. The operating system may include a base, a drive mechanism operably associated with the base to provide an input torque, a transmission operably associated with the drive mechanism to selectively transmit the input torque, an engagement arm movably associated with the base and engageable with the transmission, and an actuator arm operably associated with the base and the engagement arm to move the engagement arm relative to the transmission. The actuator arm may be movable about a first axis. The engagement arm may be movable about a second axis that is generally transverse to the first axis. The actuator arm may be positioned relative to the transmission so that the actuator arm does not engage the transmission. 
     This summary of the disclosure is given to aid understanding, and one of skill in the art will understand that each of the various aspects and features of the disclosure may advantageously be used separately in some instances, or in combination with other aspects and features of the disclosure in other instances. Accordingly, while the disclosure is presented in terms of examples, it should be appreciated that individual aspects of any example can be claimed separately or in combination with aspects and features of that example or any other example. 
     This summary is neither intended nor should it be construed as being representative of the full extent and scope of the present disclosure. The present disclosure is set forth in various levels of detail in this application and no limitation as to the scope of the claimed subject matter is intended by either the inclusion or non-inclusion of elements, components, or the like in this summary. Moreover, reference made herein to “the present invention” or aspects thereof should be understood to mean certain examples of the present disclosure and should not necessarily be construed as limiting all examples to a particular description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate examples of the disclosure and, together with the general description given above and the detailed description given below, serve to explain the principles of these examples. 
         FIGS.  1 A through  1 F  are isometric views of a mechanically-operated covering with a shade portion in various positions, while  FIG.  1 G  is an isometric view of a motorized covering. 
         FIGS.  2 A and  2 B  are section views taken along line  2 A- 2 A as shown in  FIG.  1 A  and line  2 B- 2 B as shown in  FIG.  1 D  of one example of a roller with a shade material unwrapped from and wrapped about the roller, respectively. 
         FIGS.  3 A,  3 B, and  3 C  are a distal isometric view, a distal elevation view, and a side elevation view, respectively, of one example of an operating system. 
         FIGS.  4 A and  4 B  are an exploded, distal isometric view and an exploded, proximal isometric view, respectively, of the operating system shown in  FIGS.  3 A through  3 C . 
         FIGS.  5 A,  5 B, and  5 C  are a distal elevation view, a section view taken along line  5 B- 5 B as shown in  FIG.  5 A , and a section view taken along line  5 C- 5 C as shown in  FIG.  5 A , respectively, of the base shown in  FIGS.  4 A and  4 B . 
         FIGS.  6 A and  6 B  are an exploded, distal isometric view and an exploded, proximal isometric view, respectively, of the drive mechanism shown in  FIGS.  4 A and  4 B . 
         FIG.  7    is a proximal elevation view of the spool spring shown in  FIGS.  6 A and  6 B . 
         FIGS.  8 A,  8 B, and  8 C  are a proximal elevation view, a distal elevation view, and a side elevation view, respectively, of the spool shown in  FIGS.  6 A and  6 B . 
         FIGS.  9 A and  9 B  are an exploded, distal isometric view and an exploded, proximal isometric view, respectively, of the transmission shown in  FIGS.  4 A and  4 B . 
         FIG.  10    is a distal elevation view of the clutch element shown in  FIGS.  9 A and  9 B . 
         FIGS.  11 A and  11 B  are a side elevation view and a proximal cross-sectional isometric view, respectively, of the axle shown in  FIGS.  9 A and  9 B . 
         FIGS.  12 A and  12 B  are a distal isometric view and a distal elevation view, respectively, of one of the wrap springs shown in  FIGS.  9 A and  9 B . 
         FIGS.  13 A and  13 B  are a side elevation view and a proximal cross-sectional isometric view, respectively, of the sun gear shown in  FIGS.  9 A and  9 B . 
         FIGS.  14 A and  14 B  are a side elevation view and a proximal cross-sectional isometric view, respectively, of the planetary gear carrier shown in  FIGS.  9 A and  9 B . 
         FIGS.  15 A and  15 B  are a proximal elevation view and a side elevation view, respectively, of the ring gear shown in  FIGS.  9 A and  9 B . 
         FIGS.  16 A and  16 B  are side elevation views of the actuator assembly shown in  FIGS.  4 A and  4 B  in a retraction mode and an extension mode, respectively. 
         FIGS.  17 A through  17 F  are a distal elevation view, a proximal elevation view, a side elevation view, another side elevation view, yet another side elevation view, and a further side elevation view, respectively, of the lock arm shown in  FIGS.  16 A and  16 B . 
         FIGS.  18 A through  18 E  are a distal elevation view, a proximal elevation view, a side elevation view, another side elevation view, and yet another side elevation view of the shift arm shown in  FIGS.  16 A and  16 B . 
         FIG.  19    is an isometric view of the cross pin shown in  FIGS.  16 A and  16 B . 
         FIGS.  20 A and  20 B  are a distal isometric view and a distal elevation view, respectively, of one example of an assembly of an end cap, a spool assembly, a clutch element, and an actuator assembly of the operating system shown in  FIGS.  4 A and  4 B .  FIG.  20 C  illustrates the assembly of  FIG.  20 B  with an electrically controllable actuator mechanism. 
         FIG.  21 A  is a proximal isometric view of the transmission and the actuator assembly shown in  FIGS.  4 A and  4 B  positioned in a retraction mode. 
         FIGS.  21 B and  21 C  are proximal elevation views of the transmission and the actuator assembly shown in  FIG.  21 A  with the clutch element in a disengaged and an engaged position, respectively. 
         FIG.  21 D  is a proximal isometric view of the transmission and the actuator assembly of the operating system shown in  FIGS.  4 A and  4 B  positioned in an extension mode. 
         FIGS.  22 A and  22 B  are a distal isometric view and a distal elevation view, respectively, of an assembled base, drive mechanism, clutch element, axle, brake mechanism, and actuator assembly of the operating system shown in  FIGS.  4 A and  4 B . 
         FIG.  23    is a proximal elevation view of the transmission and the actuator assembly with the axle removed to illustrate the interaction between the wrap springs and the sun gear. 
         FIGS.  24 A and  24 B  are cross-sectional views of the operating system of  FIGS.  3 A through  4 B  taken along the line  24 A,B- 24 A,B as shown in  FIG.  3 B . 
         FIG.  25    is a section view of another example of an operating system. 
         FIGS.  26 A and  26 B  are distal elevation views of the operating system of  FIG.  25    in an extension and a retraction mode, respectively. 
     
    
    
     It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the disclosure or that render other details difficult to perceive may have been omitted. In the appended drawings, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a letter that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label. It should be understood that the claimed subject matter is not necessarily limited to the particular examples or arrangements illustrated herein. 
     DETAILED DESCRIPTION 
     The present disclosure provides an operating system for a covering for an architectural opening. The operating system may be a fully contained module mounted on an end of a head rail of the covering and may support an end of an associated roller. The operating system may include a retraction mode and an extension mode. When in the retraction mode, the operating system is operable to raise or retract a shade portion of the covering. When in the extension mode, the operating system is operable to lower or extend the shade portion of the covering. 
     The operating system may utilize a single operating element, such as a cord or ball chain, to switch the operating system between the retraction and extension modes and, once in the retraction mode, to retract or lift the shade portion of the covering. To switch between modes, an operator may move the operating element in preset directions. In one implementation, a downward motion shifts the operating system into the retraction mode, while a lateral motion shifts the operating system into the extension mode. 
     Once in the retraction mode, in one implementation a single retractable operating element may be manipulated by an operator with a motion of vertical, reciprocating strokes to retract or lift the shade portion of the covering. A brake element or mechanism may inhibit or prevent the shade portion of the covering from extending or lowering across the architectural opening during retraction. To shift the operating system into the extension mode, an operator may move the operating element in a transverse direction relative to an extension/retraction direction of the shade portion. 
     Once in the extension mode, the shade portion may extend without further action by the operator. In one implementation, once the operating system is shifted into the extension mode, the shade portion of the covering may lower automatically under the influence of gravity. The operating system may include a speed governing device to control or regulate the extension or lowering speed of the shade portion of the covering. 
     Referring to  FIGS.  1 A through  1 F , a retractable covering  10  for an architectural opening is provided. The retractable covering  10  includes a head rail  14 , a bottom rail  18 , and a shade portion, for example a flexible shade  22 , extending between the head rail  14  and the bottom rail  18 . The head rail  14  includes two opposing end caps  26 A,  26 B, which may enclose the ends of the head rail  14  to provide a finished appearance. The bottom rail  18  may extend horizontally along a lower edge of the shade material  22  and may function as a ballast to maintain the shade  22  in a taut condition and to aid in a gravity-assisted extension of the shade  22 . 
     The shade  22  may include vertically suspended front  30  and rear  34  sheets of flexible material, such as sheer fabric, and a plurality of horizontally-extending, vertically-spaced flexible vanes  38 . The vanes  38  may be secured along horizontal lines of attachment along front and rear edges to the front and rear sheets  30 ,  34 . The sheets  30 ,  34  and vanes  38  may form a plurality of elongated, vertically-aligned, laterally-extending, transversely-collapsible cellular units which are longitudinally secured, such as adhered, to adjacent cellular units to define a vertical stack of cellular units, which may be referred to as a cellular panel. The sheets  30 ,  34  and/or the vanes  38  may be constructed of continuous lengths of material or may be constructed of strips of material attached or joined together in an edge-to-edge, overlapping, or other suitable relationship. 
     The shade  22  may be constructed of substantially any type of material. For example, the shade  22  may be constructed from natural and/or synthetic materials, including fabrics, polymers, and/or other suitable materials. Fabric materials may include woven, non-woven, knits, or other suitable fabric types. The shade  22  may have any suitable level of light transmissivity. For example, the shade  22 , including the sheets  30 ,  34  and/or the vanes  38 , may be constructed of transparent, translucent, and/or opaque materials to provide a desired ambience or decor in an associated room. In one example, the sheets  30 ,  34  are transparent and/or translucent, and the vanes  38  are translucent and/or opaque. 
     The shade  22  may be operably associated with a roller  42  so that rotational movement of the roller  42  about a longitudinally-extending axis moves the shade  22  between extended and retracted positions. For example, rotation of the roller  42  in a first direction may retract the shade  22  to a position adjacent one or more sides of an associated architectural opening and rotation of the roller  42  in a second, opposite direction may extend the shade  22  across the opening. The shade  22  may be coupled to and wrappable about the roller  42 , as shown in  FIGS.  2 A and  2 B , so that rotation of the roller  42  causes the shade  22  to wrap around or unwrap from the roller  42  depending upon the direction of rotation, generally referred to as a roller shade. Alternatively, the shade  22  may be stackable or gatherable adjacent to or beneath the roller  42 . For example, the covering  10  may include lift elements, such as lift cords, wrappable about the roller  42  and extending between the head rail  14  and the bottom rail  18 . As the roller  42  is rotated, the lift elements are wrapped about or unwrapped from the roller  42  to effect extension or retraction of the shade  22 . 
     Still referring to  FIGS.  1 A through  1 F , the covering  10  is shown with the shade  22  in various positions.  FIG.  1 A  depicts the shade  22  in a fully extended position in which rotation of the roller  42  moves the front and rear sheets  30 ,  34  vertically (relative to each other) to shift the vane  38  material between open and closed positions. In the open or expanded position, the front and rear sheets  30 ,  34  are horizontally spaced with the vanes  38  extending substantially horizontally therebetween.  FIGS.  1 B through  1 F  depict the shade  22  in partially extended or retracted positions in which the shade  22  is in the closed position. When in the closed or collapsed position, the front and rear sheets  30 ,  34  are relatively close together and the vanes  38  extend generally vertically in an approximately coplanar, contiguous relationship with the front and rear sheets  30 ,  34 . 
     With continued reference to  FIGS.  1 A through  1 F , the covering  10  includes an operating system that may allow an operator of the covering  10  to lift or lower the bottom rail  18  between fully retracted and fully extended positions. The operating system may include a drive mechanism configured to provide an input torque to the operating system. The drive mechanism may include a crank, an electrical motor, a spring, an operating element  46  operably coupled to a pulley, or any other suitable drive element or mechanism. The operating element  46  may be a cord, ball chain, or other suitable device. The operating element  46  may have a tassel  50  coupled to a free end of the operating element  46 . 
     The operating system may be operated mechanically and/or electrically. For illustrative purposes, the example covering  10  shown in  FIGS.  1 A through  1 F  is operated mechanically with an operating element  46 . As shown in  FIG.  1 G , the covering  10  may be operated electrically with a motor  43 , a transceiver  44  operably coupled to the motor  43 , and a transmitter, such as a remote-control unit  45 , operably coupled to the transceiver  44 . 
     To retract or lift the shade  22  from the fully extended position illustrated in  FIG.  1 A , an operator may pull downward on the operating element  46  with approximately vertical, reciprocating or repeating strokes. As shown in  FIG.  1 B , upon downward movement of the operating element  46  (represented by the arrow  54 A), the shade material  22  is retracted, raised, or lifted (represented by the arrow  58 A) from the fully extended position of  FIG.  1 A . Upon reaching the bottom of the downward stroke of the operating element  46 , an operator may release or resistively raise the operating element  46  and the operating system automatically retracts or reels in the operating element  46  (represented by the arrow  54 B) for repeated actuation. 
     As shown in  FIG.  1 C , as the operating element  46  is retracted, the operating system maintains or holds the shade  22  in its new raised state. Once the operating system has retracted the operating element  46  a distance above the bottom of the stroke, an operator may pull downward on the operating element  46  in a second stroke to further retract the shade  22 , as depicted in  FIG.  1 D . This reciprocating process is repeated until the shade  22  is retracted to a desired position. The vertical stroke of the operating element  46  may vary in different implementations of the operating system. In one implementation, the operating element  46  is about 48 inches in length. The ratio of the retraction of the shade  22  to the stroke of the operating element  46  also may vary depending on the specific implementation of the operating system. In one implementation, the ratio of shade  22  retraction to operating element  46  extension is approximately 0.4. 
     To extend or lower the shade  22  from a fully or partially retracted or lifted position, an operator may pull the operating element  46  in a diagonal or lateral direction across the face of the shade  22 , as indicated by arrow  54 C in  FIG.  1 E . The diagonal or lateral movement of the operating element  46  may shift the operating system into an extending mode in which the shade  22  may extend or lower automatically via gravity. Thus, in one implementation, after transitioning the operating system into the extending mode, the operator can release the operating element  46  and walk away from the covering  10  while the shade  22  extends or lowers without operator intervention, as indicated by arrow  58 B in  FIG.  1 F . After the shade  22  is extended to a desired position, the operator can inhibit further extension, as well as retract or raise the shade  22 , if desired, by pulling the operating element  46  vertically downward to shift the operating system into the retraction mode. In this retraction mode, the shade  22  may retract in response to the reciprocating process as described above and shown in  FIGS.  1 A through  1 D . Additionally, the operating system may include a brake element or mechanism to prevent undesired extension or lowering of the shade  22  when the operating system is in the retraction mode. 
     With reference to  FIGS.  2 A and  2 B , a roller  42  is shown in lengthwise cross section.  FIG.  2 A  is a section taken along line  2 A- 2 A of  FIG.  1 A  and illustrates the roller  42  when the shade  22  is in an extended position.  FIG.  2 B  is a section taken along line  2 B- 2 B of  FIG.  1 D  and illustrates the roller  42  with a portion of the shade material  22  wrapped about the roller  42 , which may be concealed within the head rail  14 . The roller  42  may be formed in various shapes, including an approximately cylindrical tube as shown in  FIGS.  2 A and  2 B . 
     The roller  42  depicted in  FIGS.  2 A and  2 B  extends between two opposing end caps  26 A,  26 B and is rotatably coupled to the head rail  14  to retract or extend the shade  22  dependent upon the direction of rotation of the roller  42 . In one implementation, the shade  22  is wrapped about or unwrapped from a rear side of the roller  42 , with the rear side of the roller  42  positioned intermediate the front side of the roller  42  and a street side of an associated architectural opening. To actuate movement of the roller  42 , and thus the shade  22  of the covering  10 , the operating system may be operably associated with an end  66 A,  66 B of the roller  42  and serve as one of the end caps  26 A,  26 B. 
     Referring to  FIGS.  3 A through  3 C , one example of an operating system  70  is provided. The operating system  70  may be assembled as a single, modular unit that couples to one end of the head rail  14  and supports an associated end  66 A of the roller  42 . The operating system  70  may be pre-assembled and thus simplify on-site assembly of the covering  10 . The operating system  70  may be referred to as an operating module or unit. 
     Referring to  FIGS.  4 A and  4 B , the operating system  70  is shown in an exploded, sub-assembly view. The operating system  70  may include a base  74 , a drive mechanism  78 , a transmission  82 , and an actuator or shift mechanism  86 . The base  74 , the drive mechanism  78 , and the transmission  82  may be aligned along a common axis, which may be co-axial with a central axis of the roller  42 . The actuator mechanism  86  may be laterally offset from the common axis and may be coupled to the base  74  near the periphery of the transmission  82 . The actuator mechanism  86  may shift the operating system  70  between retraction and extension modes. In one implementation, the actuator mechanism  86  selectively interacts with the transmission  82  to transition the operating system between modes. 
     Referring to  FIGS.  3 A through  5 C , the operating system  70  may include a base  74  configured to serve as an end cap  26 A of the head rail  14  and to provide a foundation for the remaining components of the operating system  70 . The base  74  may have a proximal face  90  and a distal face  94 . The proximal face  90  may be exposed when attached to the head rail  14 , and the distal face  94  may confront the drive mechanism  78 , the transmission  82 , and the actuator mechanism  86 . 
     To attach the base  74  to the head rail  14 , the base  74  may include a distally-extending, peripheral flange  98 . The flange  98  may define a female receptacle  102  (see  FIG.  5 A ) configured to snugly receive a corresponding male feature of the head rail  14 . When looking at the distal face  94  of the base  74  (see  FIG.  5 A ), the flange  98  may be inset from the right or front edge  106  of the base  74  to provide lateral space for the end of the head rail  14  to occupy in abutting relationship to an outer, front surface  110  of the flange  98 . The inset distance may be designed to form a flush or seamless transition between the edge  106  of the base  74  and an outer, front surface of the head rail  14 . 
     To attach the base  74  to the drive mechanism  78  and the transmission  82 , the base  74  may include a post  114  extending distally from the distal face  94  of the base  74 , as shown in  FIGS.  4 A,  5 A, and  5 B . The post  114  may include a proximal, smooth portion  118  and a distal, splined portion  122 . That is, the smooth portion  118  may be located intermediate the distal face  94  and the splined portion  122 . The splined portion  122  may have a smaller outer diameter than the smooth portion  118 , thus defining a transitionary shoulder  126  located between the smooth and splined portions  118 ,  122  of the post  114 . The post  114  may be hollow and may have an internal wall  130  that defines an axially-extending bore  134 . The portion of the wall  130  corresponding to the splined portion  122  may be threaded. 
     With continued reference to  FIGS.  4 A,  5 A, and  5 B , the base  74  also may include a spool spring anchor  138  extending distally from the distal face  94  of the base  74  and positioned radially outward from the post  114 . The anchor  138  may form a substantially circular arc, although other configurations are contemplated. If arc-shaped, the anchor  138  may extend any suitable angle around the central axis of the post  114 . For example, the arc-shaped anchor  138  depicted in  FIG.  5 A  extends about 45 degrees around a central axis of the post  114 , although other angles more or less than 45 degrees are contemplated. 
     As shown in  FIGS.  4 A,  5 A, and  5 B , the base  74  further may include an inner annular rim  142  and an outer annular rim  146 , both of which may extend distally from the distal face  94  of the base  74 . The inner annular rim  142  is located radially outward of the post  114  and the anchor  138 . The inner annular rim  142  may form a substantially continuous ring around the post  114  to define a space  148  located radially between the inner annular rim  142  and the post  114 . The space  148  may be configured to receive the drive mechanism  78 . When the drive mechanism  78  is seated within the space  148 , a distal face of the drive mechanism  78  may be substantially flush or congruent with a distal face  150  of the inner annular rim  142 . 
     Still referring to  FIGS.  4 A,  5 A, and  5 B , the outer annular rim  146  is spaced radially outward from the inner annular rim  142  and extends distally beyond a distal face  150  of the inner annular rim  142 . That is, a distal face  154  of the outer annular rim  146  is located distally of the distal face  150  of the inner annular rim  142 . Thus, the outer annular rim  146  defines an interior space located distally of and contiguous with the space defined by the inner annular rim  142 . A portion of the outer annular rim  146  interior space extends radially outward of the inner annular rim  142  and receives a proximal portion of the transmission  82 . The base  74  may include radially-extending spokes  158  that extend between the inner and outer annular rims  142 ,  146 . The spokes  158  may be distally congruent with the distal face  150  of the inner annular rim  142 . 
     With reference to  FIGS.  4 A and  5 A , the base  74  further may define an operating element conduit  162  that extends through the inner and outer annular rims  142 ,  146 . The conduit  162  may be configured to accommodate the passage of an operating element  46 , such as a cord or ball chain. As such, the operating element  46  can be threaded through the conduit  162  so that a portion of the operating element  46  is positioned within the inner rim  142  and a portion of the operating element  46  is positioned outside of the outer rim  146 , where the operating element  46  is accessible by an operator (see  FIGS.  1 A through  1 F , for example). 
     Referring to  FIGS.  4 A,  5 A, and  5 B , the outer annular rim  146  may form a discontinuous ring around the inner annular rim  142  so that a portion of the inner annular rim  142  is not surrounded by the outer annular rim  146 . A lock component of the actuator mechanism  86  may be operably coupled to the base  74  radially outward of, and adjacent to, the unsurrounded portion of the inner annular rim  142 , which also may be described as the missing section or gap in the outer rim  146 . In one implementation, the lock component of the actuator mechanism  86  is selectively positioned near the inner annular rim  142  to shift the operating system  70  into the retraction mode and away from the inner annular rim  142  to shift the operating system  70  into the extension mode. 
     Referring to  FIG.  5 A , adjacent to an upper end of the unsurrounded portion of the inner annular rim  142 , the base  74  may include a boss  166  that extends distally from the distal face  94  of the base  74 . The boss  166  may define a substantially cylindrical pivot aperture  170  configured to pivotably seat the lock component of the actuator mechanism  86 . The boss  166  may include a recessed portion  174  to delimit a pivotable range of the lock component of the actuator mechanism  86 . Adjacent to the boss  166  and radially outward from the missing section or gap of the outer rim  146 , the base  74  may include placement tabs  178  that protrude from an inner wall of the flange  98  to define a seat for a biasing element, such as a spring. 
     With reference to  FIGS.  4 A and  5 A , adjacent to the operating element conduit  162 , the outer annular rim  146  may be positioned radially inward of the flange  98  in an overlapping relationship. The outer annular rim  146  and the flange  98  may each include an opposing guide rail  182 A,  182 B that extend toward each other to define a gap therebetween. A shifting component of the actuator mechanism  86  may be positioned between the opposing guide rails  182 A,  182 B. 
     Below the guide rails  182 A,  182 B, the base  74  may include a pair of spaced protuberances  186 A,  186 B that extend laterally between the outer annular rim  146  and the flange  98 . The protuberances  186 A,  186 B may protrude distally from the distal face  94  of the base  74 , and each of the protuberances may include an arcuate or curved surface that oppose each other to define a seat for a cross pin  190  (see  FIG.  19   ). Near the terminal ends of the protuberances  186 A,  186 B, the flange  98  and the outer annular rim  146  each may include a recession or opening, such as the aperture  192  formed in the flange  98 , to house the ends of the cross pin  190 . 
     Referring now to  FIGS.  4 A,  4 B, and  6 A through  8 C , an example drive mechanism  78  of the operating system  70  is provided. The depicted drive mechanism  78  comprises a spool assembly having a spool  194  biased by a power or spool spring  198 . Although as previously discussed, the operating system may be motorized. 
     The spool  194 , as shown in  FIG.  8 C , may include a proximal face  210 , a distal face  214 , and a circumferential groove  218  formed between the proximal and distal faces  210 ,  214 . As shown in  FIGS.  4 A,  4 B,  6 A,  6 B,  8 A, and  8 B , the spool  194  also may include a central aperture  226 , defined by a substantially cylindrical wall  222 , that is sized to receive the smooth portion  118  of the post  114  of the base  74 . During operation, the wall  222  of the spool  194  may rotatably bear against the smooth portion  118  of the post  114 . 
     With reference to  FIGS.  6 B and  8 A , the proximal face  210  of the spool  194  has a proximal abutment surface  230  positioned proximal and radially outward from an interior cavity  234 . A spool spring anchor  238  may be located within the cavity  234 . The anchor  238  may form a substantially circular arc, although other configurations are contemplated. The arc-shaped anchor  238  may extend any suitable angle around the central axis of the aperture  226 . For example, the arc-shaped anchor  238  depicted in  FIG.  5 A  extends about 60 degrees around a central axis of the aperture  226 , although other angles more or less than 60 degrees are contemplated. When the operating system  70  is assembled, the proximal abutment surface  230  of the spool  194  may bear against the distal face  94  of the base  74 , the outer periphery of the spool  194  may be disposed radially inward of the inner annular rim  142 , and the distal face  214  of the spool  194  may be approximately flush with the distal face  150  of the inner annular rim  142 . 
     The spool spring  198 , as shown in  FIGS.  6 A through  7   , is configured to provide a spool  194  retraction force and may be housed within the inner cavity  234  of the spool  194 . The spool spring  198  may include a number of windings extending between an inner end portion  202  and an outer end portion  206 . The inner and outer end portions  202 ,  206  each may be folded over to form an inner and outer hook, respectively, so that when the operating system  70  is assembled, the inner end portion  202  engages the anchor  138  of the base  74  and the outer end portion  206  engages the anchor  238  of the spool  194 . In this configuration, when viewing the distal face  94  of the base  74 , a clockwise rotation of the spool  194  relative to the base  74  radially contracts the windings of the spool spring  198  to create a counterclockwise biasing force, resulting in a spool retraction force. 
     Referring to  FIGS.  6 A,  8 B, and  8 C , the distal face  214  of the spool  194  may include an embossed ring  240  encircling the central aperture  226  and a pair of diametrically opposed clutch tabs  242  located along a radially outward portion of the ring  240 . Each of the clutch tabs  242  may be formed in an apostrophe or comma shape with a radially thicker clockwise trailing edge  246  and a radially thinner clockwise leading edge  250 . Each of the tabs  242  also may include a curved inner surface or wall  254  that extends between the trailing and leading edges  246 ,  250 . Additionally, each of the tabs  242  may include a ramp or cam surface  256  that inclines outward from the leading edge  250  toward the trailing edge  246 . In other words, the cam surface  256  may incline in a counterclockwise direction from the leading edge  250  of each of the tabs  242 . Near the trailing edge  246  of each of the tabs  242 , the ramp or cam surface  256  may terminate at a stop shoulder  258 . 
     Referring to  FIG.  8 C , the spool  194  includes a circumferential groove  218  formed between the proximal and distal faces  210 ,  214 . Although not depicted in  FIG.  8 C , the operating element  46  may be wound around the spool  194  and disposed within the groove  218 , which may be formed to receive various lengths of the operating element  46 . For example, in one implementation, about 48 inches of the operating element  48  may be wound around and located within the groove  218 . To couple the operating element  48  to the spool  194 , one end of the operating element  48  may be routed through a slot  262 A or  262 B (see  FIG.  8 A ) formed in a proximal side wall  266 A of the groove  218 , placed within the inner cavity  234  of the spool  194 , and knotted, secured, or otherwise configured to prevent that end of the operating element  46  from being displaced from the cavity  234 . After being wound around the groove  218 , the other end of the operating element  46  may be routed through a slot  270  formed in a distal side wall  266 B of the groove  218  (see  FIG.  8 C ) and temporarily secured distally of the distal side wall  266 B until the spool assembly is operably coupled to the base  74 . 
     Referring now to  FIGS.  9 A and  9 B , an example transmission  82  of the operating system  70  is shown in exploded below. The transmission  82  includes a clutch element  274 , an axle  278 , at least one wrap spring  282 , a sun gear  286 , a plurality of planet gears  290 , an annulus or ring gear  294 , a planet carrier  298 , and a fastener  302 . When assembled, the components of the transmission  82  may be coaxially aligned with the post  114  of the base  74 . During shade  22  retraction, the transmission  82  generally receives an input torque from the drive mechanism  78  and provides an output torque to the roller  42 . The transmission  82  may provide a gear reduction, such as by the example planetary gear system, to reduce the amount of input torque required to retract the shade  22 . During shade  22  extension, the transmission  82  may be disengaged from the other components of the operating system  70  so that the roller  42  can rotate in an extension or lowering direction via gravity. 
     Referring to  FIGS.  9 A through  10   , the clutch element  274  may serve as a one-way clutch transferring torque from the spool  194  to the sun gear  286  during extension of the operating element  46 , while allowing free rotation of the spool  194  relative to the sun gear  286  during retraction of the operating element  46 . With reference to  FIG.  10   , the clutch element  274  may include a body  306  with two resilient arms  310 A,  310 B each having a connected end  314  and a free end  318 . The body  306  also may include an inner bearing surface  330  and opposing outer bearing surfaces  334 A,  334 B that each extend between proximal and distal faces  322 ,  326  of the clutch element  274 . The outer bearing surfaces  334 A,  334 B each may terminate at shoulders, namely a clockwise rotation shoulder  338  and a counterclockwise rotation shoulder  342 . 
     The resilient arms  310 A,  310 B each wrap about the bearing surfaces  334 A, B in a radially spaced relationship and in a counterclockwise direction. Each of the resilient arms  310 , in combination with a corresponding bearing surface  334 , define a gap  346  closed at one end by the clockwise rotation shoulder  338  and open at the other, entrance end. The free end  318  of each of the arms  310  include an outward directed barb  350 . When the operating system  70  is assembled, the inner surface  330  of the body  306  rotatably bears against the smooth portion  118  of the post  114  of the base  74  and the proximal face  322  of the body  306  abuts against the ring  240  of the spool  194 . 
     As shown in  FIGS.  20 A and  20 B , the clutch element  274  may be axially positioned on the smooth portion  118  of the post  114  of the base  74 . Upon extension of the operating element  46  (see  FIGS.  1 A and  1 D ), the spool  194  rotates in a shade retraction direction (as indicated by arrow A in  FIG.  20 B ) about the post  114 . The rotation of the spool  194  moves the clockwise leading edge  250  of each of the clutch tabs  242  radially between the resilient arms  310  and the body  306  of the clutch element and towards the clockwise rotation shoulder  338  located at the intersection of the arms  310  and the body  306 . As the leading edges  250  of the clutch tabs  242  move toward the shoulder  338 , the resilient arms  310  ride up the cam surfaces  256  of the clutch tabs  242  and are expanded radially outward, thereby increasing the effective outer diameter of the clutch element  274 . Once the stop shoulders  258  of the clutch tabs  242  contact the free ends  318  of the resilient arms  310 , the clutch tabs  242  drive the arms  310 , and hence the clutch element  274 , in a clockwise direction. 
     During retraction of the operating element  46  (see  FIG.  1 C ), the spool  194  rotates in a shade extension direction (as indicated by arrow B in  FIG.  20 B ) about the post  114 . The shade extension rotation of the spool  194  moves the clockwise trailing edge  246  of each of the clutch tabs  242  towards the counterclockwise rotation shoulder  342 . As the trailing edges  246  of the clutch tabs  242  move toward the shoulder  342 , the resilient arms  310  descend down the cam surfaces  256  of the clutch tabs  242  and contract radially inward to a non-deformed state, thereby decreasing the effective outer diameter of the clutch element  274 . Once the trailing edges  246  of the clutch tabs  242  contact the shoulder  342 , the clutch tabs  242  drive the clutch element  274  in the shade extension direction. However, as will be discussed below, the decreased effective outer diameter of the clutch element  274  isolates the rotation of the spool  194  from the transmission  82 , thereby enabling retraction of the operating element  46  without impacting the position of the shade  22 . 
     Referring to  FIGS.  9 A,  9 B,  11 A, and  11 B , one example of an axle  278  of the operating system  70  is provided. When the operating system  70  is assembled, the axle  278  is keyed to the base  74  to prevent rotation of the axle  278  relative to the base  74 . That is, the axle  278  is non-rotatably coupled to the base  74 . Referring to  FIGS.  11 A and  11 B , the example axle  278  includes an interior wall  352  and an exterior wall  354 . The interior wall  352  may define a bore  358  extending longitudinally through the axle  278 . The proximal portion of the interior wall  352  may include a cylindrical section  362 , a splined section  366 , and a transition section  370  located intermediate the cylindrical section  362  and the splined section  366 . The cylindrical section  362  may have a larger diameter than the splined section  366 , which includes alternating ribs and grooves. The transition section  370  may be arcuate, curved, or chamfered. The distal portion of the interior wall  352  may be substantially smooth and cylindrical. When the operating system  70  is assembled, the cylindrical section  362  may abut the smooth portion  118  of the post  114  of the base  74 , the splined section  366  may matingly engage the splined portion  122  of the post  114 , and the proximal face of the stepped shoulder of the splined section  366  may abut the distal face of the post  114 . 
     The exterior wall  354  of the axle  278  may include a radially-extending flange  374 , a tapered distal surface  378 , and a cylindrical surface  382  located intermediate the flange  374  and the tapered surface  378 . A step shoulder  386  may be formed between the larger diameter cylindrical surface  382  and the smaller diameter tapered surface  378 . The axle  278  also may include a proximal face  390  and a distal face  394 . When the operating system  70  is assembled, the proximal face  390  may abut the distal face  326  of the clutch element  274  and the distal face  394  may bear against the underside of the head of the threaded fastener  302 . 
     Referring to  FIGS.  9 A,  9 B,  12 A, and  12 B , a brake element or mechanism is provided. The example brake element includes two identical wrap springs  282 . When the operating system  70  is assembled, the wrap springs  282  are interference fit onto the cylindrical section  362  of the axle  278 , as shown in  FIGS.  22 A and  22 B . As such, the wrap springs  282  function as a one-way brake and are configured to rotationally slip around the axle  278  in a shade retraction direction (as indicated by arrow A in  FIG.  22 B ) and clamp or lock onto the axle  278  in a shade extension direction (as indicated by arrow B in  FIG.  22 B ). Thus, in one implementation, as the operating element  46  is extended from the spool  194 , the spool  194  rotates and the wrap springs  282  rotationally slip about the axle  282  to raise or retract the shade  22 . However, as the operating element  46  is reeled in by the spool  194 , the wrap springs  282  lock about the axle  278  to prevent unintentional extension or lowering of the shade  22 . 
     With reference to  FIGS.  12 A and  12 B , each wrap spring  282  includes terminal end segments  398 ,  402  spatially separated by a number of windings. One end segment  398  may be directed slightly outward to prevent inadvertent catching, gouging, or scarring of the cylindrical section  362  of the axle  278 . The other end segment  402  may extend radially outward to form a tang. Although two wrap springs  282  are provided for illustrative purposes, other configurations are contemplated. For instance, any number of wrap springs  282 , such as one, two, or more than two, may be utilized. In addition, if a plurality of wrap springs  282  are used, the wrap springs  282  may be different from each other. 
     Referring to  FIGS.  9 A,  9 B,  13 A, and  13 B , an example sun gear  286  of the transmission  82  is provided. The sun gear  286  may include external gear teeth  404  and a hollow interior. The sun gear  286  also may include an inner surface defining a proximal clutch portion  406  and a distal brake portion  410 . The clutch portion  406  may include circumferentially spaced, radially-inward directed ridges  414  that define recesses  418  between the ridges  414 . The clutch portion  406  may receive the clutch element  274 , as shown in  FIGS.  21 A through  21 D . 
     When the resilient arms  310  of the clutch element  274  are in a non-deformed state, as shown in  FIG.  21 B , the effective outer diameter of the clutch element  274  is smaller than the inner diameter of the ridges  414  of the sun gear  286 . As previously discussed, the clutch element  274  may be in a non-deformed state, and thus may rotate within the sun gear  286  without interference, when the spool  194  rotates in a shade extension direction. As such, during retraction of the operating element  46 , the clutch element  274  may rotatably isolate the sun gear  286  from the spool  194  or any other suitable drive mechanism. 
     When the resilient arms  310  of the clutch element  274  are in a deformed state, as shown in  FIG.  21 C , the barbs  350  of the radially-expanded, resilient arms  310  are located within opposing recesses  418  and engage opposing ridges  414  to transfer rotation of the spool  194  to the sun gear  286 . As previously discussed, the clutch element  274  may be in a radially-expanded state, and thus rotatably couple the sun gear  286  to the spool  194 , when the spool  194  rotates in a shade retraction direction. As such, during extension of the operating element  46 , the clutch element  274  may rotatably couple the sun gear  286  to the spool  194  (as shown in  FIG.  21 C ) or any other suitable drive mechanism. 
     With reference to  FIG.  13 B , the brake portion  410  of the sun gear  286  may extend distally from the clutch portion  406 . The brake portion  410  may include a counterbore section  422 , a radially inturned lip  426 , and at least one slot  430  extending longitudinally between the proximal counterbore section  422  and the distal lip  426 . The counterbore section  422  may be configured to seat the flange  374  of the axle  278 . When assembled, the proximal face  390  of the axle  278  may be approximately flush or congruent with the leading proximal edge of the brake portion  410  (as shown in  FIG.  25 B ). Also when assembled, the radially inturned lip  426  may rotatably bear against a distal portion of the cylindrical surface  382  of the axle  278  and may be distally aligned with the step shoulder  386  of the axle  278  (see  FIG.  25 B ). The radially inturned lip  426  also may axially retain the wrap spring  282  around the cylindrical surface  382  of the axle  278 . 
     The at least one slot  430  of the brake portion  410  of the sun gear  286  may be configured to receive the tangs  402  of the wrap springs  282  to rotatably lock the wrap springs  282  and the sun gear  286  depending on the direction of rotation. As shown in  FIG.  23    (axle  278  is removed for clarity), two wrap springs  282  are positioned coaxially within the sun gear  286 . The tang  402  of each wrap spring  282  extends into one of the four circumferentially spaced slots  430  so that the rotation of the sun gear is rotatably linked to each wrap spring  282 . 
     With continued reference to  FIG.  23   , upon extension of the operating element  46  (see  FIGS.  1 B and  1 D ), the spool  194  rotates in a shade retraction direction (as indicated by arrow A in  FIG.  23   ), the clutch tabs  242  radially expand the resilient arms  310 , and the barbs  350  engage the ridges  414  of the clutch portion  406  of the sun gear  286  to transmit the spool  194  torque to the sun gear  286 . Upon rotation of the sun gear  286  in the shade retraction direction, a wall of the slot  430  contacts the tang  402  of the wrap springs  282  and radially expands the windings of the at least one wrap spring  282 . The radial expansion of the windings permits the wrap springs  282  to rotationally slip around the stationary axle  278  in the shade retraction direction. 
     Upon retraction of the operating element  46  (see  FIG.  1 C ), the spool  194  rotates in a shade extension direction (as indicated by arrow B in  FIG.  23   ), the clutch tabs  242  contact the counterclockwise rotation shoulders  342 , and the clutch element  274  rotates freely within the clutch portion  406  of the sun gear  286  without transmitting the spool  194  torque to the sun gear  286 . Thus, torque from the spool  194  is not transmitted to the sun gear  286  in the shade extension direction. 
     In addition to the clutch element  274  not transmitting torque in the shade extension direction from the spool  194  to the sun gear  286 , the wrap springs  282  may prevent the sun gear  286  from rotating in the shade extension direction due to the weight of the shade  22  imparting a shade extension torque on the roller  42 . Upon rotation of the sun gear  286  in the shade extension direction, a wall of the slot  430  contacts the tang  402  of the wrap springs  282  and radially contracts the windings about the cylindrical surface  382  of the axle  278 . The radial contraction of the windings prevents rotation of the sun gear  286  about the stationary axle  278  in the shade extension direction. In this manner, the wrap springs  282  act as a brake mechanism to lock or maintain the desired position of the shade  22  relative to the architectural opening. 
     Referring to  FIGS.  9 A,  9 B,  14 A, and  14 B , an example planetary gear carrier  298  of the transmission  82  is provided. The planetary gear carrier  298  may include a carrier portion  434  and a bearing portion  438 . The carrier portion  434  may include a radially extending flange  442  with a proximal face  446 . The carrier portion  434  also may include a plurality of pins  450  that extend proximally from the face  446 . Each of the pins  450  may support a planet gear  290  (shown in  FIGS.  9 A and  9 B ). The carrier portion  434  may include any suitable number of pins  450 . In one implementation, the carrier portion  434  includes at least three pins  450 . In the depicted implementation, the carrier portion  434  includes six pins  450 . 
     The bearing portion  438  of the gear carrier  298  may be configured to fit into an end of the roller  42  and transmit motion between the gear carrier  298  and the roller  42 . The bearing portion  438  may include a plurality of ribs  454  extending distally from the flange  442  and radially outward from a tiered wall  458 . The ribs  454  may be configured to rotatably couple the gear carrier  298  and roller  42 . For example, the ribs  454  may frictionally engage an inner portion of the roller  42 , may key into corresponding interior features of the roller, or otherwise couple the components together. The bearing portion  438  may include any suitable number of ribs  454 . In one implementation, the plug portion  438  includes at least three ribs  454 . In the depicted implementation, the plug portion  438  includes six ribs  454  (see  FIG.  9 A ). 
     The tiered wall  458  of the gear carrier  298  may define a larger diameter proximal cavity  462  and a smaller diameter distal cavity  466 . The proximal cavity  462  may be configured to house the sun gear  286  (except for the external gear teeth  404 ). The distal cavity  466  may be configured to house, and may radially abut, the tapered surface  378  of the axle  278 . Although depicted as an integral unit, the carrier portion  434  and the bearing portion  438  of the gear carrier  298  may be individual components that are coupled together. 
     Referring to  FIGS.  9 A,  9 B,  15 A, and  15 B , an example annulus or ring gear  294  of the transmission  82  is provided. The ring gear  294  may include inwardly directed gear teeth  470 , outwardly directed teeth  474  located radially outward from the gear teeth  470 , and a series of bridges  478  extending radially between the inwardly directed gear teeth  470  and the outwardly directed teeth  474 . The bridges  478  may be spaced apart from one another to reduce the amount of material, and thus the weight, of the ring gear  294 . In some implementations the ring gear  294  may be constructed of plastic, in which case the spaces between the bridges  478  may reduce warpage, sinks, and/or voids. The ring gear  294  may include a circumferential flange or cap  482  extending radially outward and distally from the outward directed teeth  474 . 
     With reference to  FIGS.  21 A through  21 D  and  FIG.  23   , when the operating system  70  is assembled, the planet gears  290  mesh between the sun gear  286  and the ring gear  294 . The sun gear  286 , planet gears  290 , ring gear  294 , and planet carrier  298  generally form a planetary gear set or gear reduction unit, thereby reducing the amount of force required to retract or raise the shade  22 . In one implementation, the gear ratio of the planetary gear set is 2.5. 
     As previously discussed, during extension of the operating element  46  (see  FIGS.  1 B and  1 D ), the sun gear  286  rotates relative to the stationary axle  278  in a shade retraction direction. If the ring gear  294  is rotatably locked during this rotation of the sun gear  286 , the planet gears  290  rotate about their respective pins  450  and orbit around the sun gear  286 . The orbiting motion of the planet gears  290  rotate the planet carrier  298 , which in turn rotates the roller  42  in a shade retraction direction. 
     During retraction of the operating element  46  (see  FIG.  1 C ), the sun gear  286  is rotatably isolated from the spool  294  and thus does not rotate the planet carrier  298 . In addition, during retraction of the operating element  46 , the weight of the shade  22  suspended from one edge of the roller  42  may impart a torque on the roller in the shade extension direction. This torque may be transferred to the planet gears  290  through the planet carrier  298 . As previously discussed, the wrap springs  282  may prevent rotation of the sun gear  286  in the shade extension direction. Thus, if the sun gear  286  and the ring gear  294  are rotatably locked, the planet gears  290  are prevented from moving, which in turn maintains the shade  22  in the current position. Alternatively, if the ring gear  294  is not rotatably locked, the planet gears  290  may orbit about the sun gear  286  in the shade extension direction to extend the shade  22  across the architectural opening. 
     Referring now to  FIGS.  4 A,  4 B, and  16 A through  19   , an example actuator or shift mechanism  86  of the operating system  70  is provided. The actuator mechanism  86  selectively engages the transmission  82  to transition the operating system  70  between retraction and extension modes. Although the following discussion describes an actuator mechanism  86  shifted mechanically by an operating element  46 , the actuator mechanism  86  may be mechanically and/or electrically actuated. For instance, as shown in  FIG.  20 C , an electrically-controlled actuator  484  may be attached to the base  74  and positioned to selectively shift the actuator mechanism  86  between retraction and extension modes. The actuator  484  may interact with the actuator mechanism  86  in various manners, such as electromagnetically, to move the actuator mechanism  86 . The actuator  484  may be electrically coupled with a transceiver operable to receive signals from a remote transmitter, such as a remote-control unit  45  (see  FIG.  1 G ), and transmit signals to a remote receiver. Electrically-controlled linear and/or rotary actuators may be used. 
     In one implementation, an operator shifts the actuator mechanism  86  between modes by manipulating an operating element  46  in a predefined direction. For instance, the operator may pull the operating element  46  across the face of the shade  22  in a diagonal or lateral movement (e.g., arrow  54 C in  FIG.  1 E ) to shift the actuator mechanism  86  into a shade extension mode, thereby permitting the shade  22  to automatically extend or lower, such as via gravity. Once in the shade extension mode, the operator may shift the actuator mechanism  86  into a shade retraction mode (which stops the extension) by pulling the operating element  46  vertically downward or in a direction opposite to that shown in  FIG.  1 E . 
     Referring to  FIGS.  16 A,  16 B,  21 A, and  21 D , the actuator mechanism  86  may include an engagement or lock arm  490  and an actuator or shift arm  486 . The lock arm  490  may be pivotably associated with the base  74  of the operating system  70 . In one implementation, the lock arm  490  has a preset pivotable range. At one end of the pivotal range, the lock arm  490  engages the transmission  82  to substantially prevent rotation of the roller  42  in a shade extending direction, which may be referred to as the shade retraction mode. At the other end of the pivotal range, the lock arm  490  disengages from the transmission  82  to permit rotation of the roller in the shade extending direction, which may be referred to as the shade extension mode. The lock arm  490  may be biased toward the shade retraction mode by a biasing element such as a spring. 
     An example lock arm  490  is provided in  FIGS.  17 A through  17 F . The lock arm  490  may include a post  494  configured to be rotatably seated within the pivot aperture  170  of the base  74 , a cutout  498  configured to receive a portion of the boss  166 , and an overpass  502  located distally of the cutout  498  and configured to be seated within the recessed portion  174  of the boss  166  to limit the pivotal range of the lock arm  490 . The post  494 , the boss  166 , or both may include catch or snap features to axially interlock the post  494  within the pivot aperture  170  while permitting rotation of the lock arm  490  relative to the base  74 . A biasing element, such as a torsion spring, may be associated with the post  494  and the boss  166  to rotationally bias the lock arm  490  toward the shade retraction mode, for example. The pivot axis of the lock arm  490  may be generally parallel to a central longitudinal axis of the transmission  82 . When assembled, the post  494  may extend in a proximal direction towards the base  74  and away from the roller  42 . 
     The lock arm  490  also may include an engagement tooth  518  configured to engage the transmission  82  when the actuator mechanism  86  is in the shade retraction mode. When the actuator mechanism  86  is in the shade retraction mode, as shown in  FIGS.  21 A through  21 C , the engagement tooth  518  of the lock arm  490  may matingly engage or intermesh with the outwardly directed teeth  474  of the ring gear  294  to substantially prevent rotation of the ring gear  294 . When the actuator mechanism  86  is in the shade extension mode, the lock arm  490  may be pivoted away from the transmission  82  so that the engagement tooth  518  is spatially separated from the outwardly directed teeth  474  of the ring gear  294  to permit rotation of the ring gear  294 . The tooth  518  may include a buttress or rib  520  extending proximally from the tooth  518  to provide additional rigidity to the tooth  518 . The distal surface  526  of the lock arm  490 , including the engagement tooth  518 , may be approximately planar and configured to abut the proximal face of the circumferential flange or cap  482  of the ring gear  294 . 
     As previously discussed, the actuator mechanism  86  may be biased toward the shade retraction mode. In the implementation depicted in  FIGS.  17 A through  17 F , the lock arm  490  includes a mandrel  522  configured to seat one end of a compression spring  524  (shown in  FIGS.  20 B and  22 B ), with the other end of the compression spring  524  seated within the placement tabs  178  protruding from the flange  98  of the base  74  (see  FIG.  5 A ). In this implementation, the compression spring  524  pivots the lock arm  490  into the shade retraction mode in which the engagement tooth  518  is engaged with an outwardly directed tooth  474  of the ring gear  294  to prevent rotation of the ring gear  294 . The mandrel  522  may be conical, cylindrical, or any other suitable shape. 
     With continued reference to  FIGS.  17 A through  17 F , the lock arm  490  additionally may include a biasing or contact surface  506 , a retention surface  510 , and a detent  514  located intermediate the contact surface  506  and the retention surface  510 . The contact surface  506  may extend in a distal direction from the detent  514  at an oblique angle relative to a longitudinal plane. The retention surface  510  may extend in a proximal direction from the detent  514  in a parallel relationship to a longitudinal plane. In other words, the biasing or contact surface  506  may be oriented at an oblique angle relative to the retention surface  510 . The detent  514  may protrude outward from the lock arm  490  relative to the contact surface  506  and the retention surface  510 , both of which may be substantially planar. The contact surface  506 , the retention surface  510 , and/or the detent  514  may be formed of a wear resistant material, which may be uniform with the lock arm  490 . In one implementation, the contact surface  506 , the retention surface  510 , and/or the detent  514  may be plated, treated, or otherwise associated with nickel or any other suitable material to provide wear resistance. 
     To transition the actuator mechanism  86  between modes, the actuator mechanism  86  may include a shift arm  486  configured to manipulate the position of the lock arm  490  relative to the transmission  82 . The shift arm  486  may be rotatably coupled to the base  74  of the operating system  70  and may have a preset rotatable range. At one end of the rotatable range, the shift arm  486  disengages the lock arm  490  from the transmission  82  to permit rotation of the roller  42  in a shade extending direction, generally referred to as the shade extension mode (see  FIGS.  16 B and  21 D ). At the other end of the rotatable range, the shift arm  486  does not interfere with the engagement of the lock arm  490  and the transmission  82 , generally referred to as the shade retraction mode (see  FIGS.  16 A and  21 A through  21 C ). When the operating system  70  is in the shade extension mode, the shift arm  486  may retain the lock arm  490  in a disengaged position relative to the transmission  82  until an external force pivots or rotates the shift arm  486  about the cross pin  190 , moving a lower portion of the shift arm  486  toward the base  74  and an upper portion of the shift arm  486  away from the base  74 , thereby shifting the operating system  70  into the shade retraction mode. The rotation axis of the shift arm  486  may be approximately perpendicular to the pivot axis of the lock arm  490 . 
     An example shift arm  486  is provided in  FIGS.  18 A through  18 E . The shift arm  486  may include a pin housing  530  configured to receive a cross pin  190  (shown in  FIG.  19   ). As such, the cross pin  190 , the pin housing  530 , or both may serve as a pivot point or fulcrum for the shift arm  486 . With reference to  FIGS.  5 A and  5 C , the pin housing  530  may be rotatably seated between the protuberances  186 A,  186 B and the ends of the cross pin  190  may be rotatably seated in opposing recesses or openings in the rim  146  and the flange  98 , such as the aperture  192  formed in the flange  98 . 
     At one end of the rotatable range of the shift arm  486 , the shift arm  486  engages the lock arm  490 , causing the lock arm  490  to disengage the outward facing teeth  474  of the ring gear  294 , generally referred to as the shade extension mode. In this mode (see  FIGS.  16 B and  21 D ), the lock arm  490  permits rotation of the ring gear  294 , thereby permitting extension of the shade  22 , which may be under the effect of gravity. At the other end of the rotatable range of the shift arm  486 , the shift arm  486  does not displace the lock arm  490 , allowing the lock arm  490  to engage the ring gear  294  under spring load, generally referred to as the shade retraction mode. In this mode (see  FIGS.  16 A and  21 A through  21 C ), the lock arm  490  prevents rotation of the ring gear  294 , thereby preventing extension of the shade  22  and enabling retraction of the shade  22 . 
     Referring back to  FIGS.  18 A through  18 E , the shift arm  486  also may include first and second lever portions or arms  534 ,  538  extending away from the pin housing  530  in different directions, which may be opposing. The first lever arm  534  may include an eyelet  542  configured to accommodate the passage of the operating element  46 . The eyelet  542  may be closed, as shown in  FIG.  18 D , or open. As shown in  FIGS.  20 A and  20 B , when the shift arm  486  is coupled to the base  74 , the eyelet  542  may be approximately vertically aligned with the operating element conduit  162  extending through inner and outer annular rims  142 ,  146  of the base  74  so that a vertical movement of the operating element  46  (see  FIGS.  1 B through  1 D ) may not pivot or rotate the shift arm  486  about the cross pin  190  but a lateral movement of the operating element  46  transverse to the rotation axis of the shift arm  486  (see  FIG.  1 E ) may pivot or rotate the shift arm  486  about the cross pin  190 . As shown in  FIG.  18 C , the first lever arm  534  also may include a guide or pathway  546  to facilitate threading of the operating element  46  through the eyelet  542 . The eyelet  542  may open through an angled bottom surface  548  of the shift arm  486 . 
     With continued reference to  FIGS.  18 A through  18 E , the second lever arm  538  may include a biasing face or surface  550  located on a proximal side of the arm  538  and a retaining shoulder  554  located on a distal side of the arm  538 , both of which may be associated with a terminal end  558  of the second lever arm  538 . The biasing face  550  may be rounded to facilitate smooth engagement with, and thus shifting of, the lock arm  490 . With reference to  FIGS.  16 A and  16 B , upon rotation of the shift arm  486  in a first direction, as indicated by arrow  562 , the biasing face  550  contacts the biasing surface  506  of the lock arm  490  to pivot the lock arm  490  about the post  494 , thereby disengaging the engagement tooth  518  from the outer teeth  474  of the ring gear  294  to permit extension of the shade  22 . Once the biasing face  550  surpasses the detent  514 , the retaining shoulder  554  engages the detent  514  and retains the lock arm  490  in the shade extension mode until a lateral force is exerted on the first lever arm  534 . The lateral force may be created by an operating element  46  extending through the eyelet  542 , which may pivot or rotate the shift arm  486  in a second direction, as indicated by arrow  566 , to overcome the detent  514  and release the lock arm  490  from the extension mode. As previously discussed, the lock arm  490  may be biased toward the engaged position or shade retraction mode and thus, once the lock arm  490  is released from engagement with the shift arm  486 , the lock arm  490  may automatically pivot into engagement with the external teeth  474  of the ring gear  294 . 
     Referring now to  FIGS.  24 A and  24 B , one example of the assembled operating system  70  is depicted in cross section. The operating system  70  may be a self-contained, modular unit that is insertable into an end of the roller  42  and may serve as an end cap  26  of the head rail  14 . In one implementation, the operating system  70  provides a thin gap between an end of the roller  42  and an associated end of the head rail  14 , thereby minimizing a light gap between the shade  22  and the architectural opening when the shade  22  is in an extended position across the opening. In one specific implementation, the distance between the end of the roller  42  and the end of the head rail  14  is about 0.44 inches. 
     With continued reference to  FIGS.  24 A and  24 B , a fastener  302  may secure the operating system  70  together. The fastener  302  may extend along a central longitudinal axis  570  of the drive mechanism  78  and the transmission  82 . As shown in  FIGS.  24 A and  24 B , the fastener  302  may threadably engage the internal wall of the post  114  of the base  74 . Additionally or alternatively, a nut, such as a lock nut, may threadably engage the fastener and may be housed within the hollow post  114  of the base  74  of the operating system  70 . 
     In operation, the operating system  70  may be selectively switched into a retraction mode or an extension mode by manipulating the position of the actuator mechanism  86 . In one implementation, a user may use the operating element  46  to switch the operating system  70  from a retraction mode into an extension mode. With reference to  FIG.  21 A , the lock arm  490  is engaged with the ring gear  294  (retraction mode). To disengage the lock arm  490  from the ring gear  294 , and thus change the rotation direction of the roller  42 , a user may pull the operating element  46  in a direction generally along a longitudinal axis of the roller  42  from a point proximate to an associated end of the roller  42  toward an opposing end of the roller  42 . This transverse movement of the operating element  46  pivots or rotates the shift arm  486  about the pivot pin  190  in a first direction  562 , moving the first or lower lever arm  534  axially away from the base  74  and the second or upper lever arm  538  axially toward the base  74  (see  FIGS.  16 A,  16 B,  20 A,  20 B, and  21 A ). During the rotation of the shift arm  486  in the first direction  562  (see  FIG.  16 A ), a face  550  of the second lever arm  538  contacts a surface  506  of the lock arm  490 , thereby pivoting the lock arm  490  radially away from the ring gear  294  to disengage the tooth  518  of the lock arm  490  from the outwardly directed teeth  474  of the ring gear  294 . 
     In one implementation, a user may use the operating element  46  to switch the operating system  70  from an extension mode into a retraction mode. With reference to  FIG.  21 D , the lock arm  490  is disengaged from the ring gear  294  (extension mode). To engage the lock arm  490  with the ring gear  294 , and thus alter the rotation direction of the roller  42 , a user may pull the operating element  46  in a vertically downward direction. Since the operating element  46  is routed downward from the operating element conduit  162  of the base  74  through the eyelet  542  of the shift arm  486  (see  FIGS.  20 A and  20 B ), upon a vertically downward movement of the operating element  46 , the slight axial offset of the eyelet  542  relative to the conduit  162  causes the operating element  46  to move the first or lower lever arm  534  toward the base  74 , which in turn moves the second or upper lever arm  538  away from the base  74 , which in turn pivots the lock arm  490  radially towards the ring gear  294  into an engaged position (retraction mode). More particularly, the downward movement of the operating element  46  pivots or rotates the shift arm  486  about the pivot pin  190  in a second direction  566 , moving the first or lower lever arm  534  axially toward the base  74  and the second or upper lever arm  538  axially away from the base  74  (see  FIGS.  16 A,  16 B,  20 A,  20 B, and  21 A ). During rotation of the shift arm  486  in the second direction  566  (see  FIG.  16 B ), a retaining shoulder  554  and a face  550  of the second lever arm  538  passes by a detent  514  of the lock arm  490 , thereby permitting the lock arm  490  to pivot radially toward the ring gear  294  under the influence of the compression spring  524  (see  FIG.  20 C ), resulting in the tooth  518  of the lock arm  490  meshing with the outwardly directed teeth  474  of the ring gear  294  (retraction mode, see  FIG.  21 A ). 
     When the lock arm  490  is engaged with ring gear  294  (retraction mode), the operating system  70  permits the shade  22  to be raised or retracted. To raise or retract the shade  22 , an operator may pull downward on the operating element  46 . While pulling in a downward direction, the movement of the operating element  46  rotates the spool  194 , which in turn increasingly tensions the spool spring  198 . In addition, the clutch element  274  engages the sun gear  286 , causing the sun gear  286  to rotate along with the spool  194 . As the sun gear  286  rotates, the ring gear  294  is prevented from rotating by the engagement of the lock arm  490  with the outwardly directed teeth  474  of the ring gear  294 . The locked ring gear  294  causes the planet gears  290  to orbit around the sun gear  286 , which in turn causes the planet carrier  298  to rotate. As the planet carrier  298  is coupled to the roller  42 , rotation of the planet carrier  298  rotates the roller  42 , retracting the shade material  22 . 
     At the end of the downward stroke, the operator releases or resistively raises the operating element  46  and the spool spring  198  correspondingly reels in the operating element  46  around the groove  218  of the spool  194 . As the operating element  46  is retracted, the clutch element isolates the sun gear  286  from the rotation of the spool  194 . Additionally, the operating system  70  prevents the roller  42  from rotating in a shade extension direction, thereby maintaining the position of the shade  22  relative to the architectural opening during the intermittent retraction of the operating element  46 . In one implementation, the sun gear  286  is rotationally locked to the stationary axle  278  in the shade extension direction by at least one wrap spring  282  and the ring gear  294  is rotationally locked by the actuator mechanism  86 . Thus, in this implementation, the sun gear  286  and the ring gear  294  prevent the planet gears  298  from orbiting about the sun gear  286 , thereby prohibiting extension of the shade material  22  across the opening when the operating system  70  is in a retraction mode. Therefore, even though the spool  194  is able to rotate and reel in the operating element  46 , the operating system  70  holds the shade  22  in place. In this fashion, the operator can cyclically pull down on and then retract the cord as many times as necessary to raise or retract the shade material  22  a desired distance, causing the spool  194  to reciprocate rotationally back and forth and the sun gear  286  to incrementally advance forward in a winding direction. 
     To switch the operating system  70  into an extension mode to extend or lower the shade  22 , the operator may move the operating element  46  in a lateral direction resulting in a diagonal extension of the operating element  46 . This lateral movement may be toward the middle of the shade  22 . The lateral movement of the operating element  46  causes the shift arm  486  to pivot or rotate, with the first or lower lever arm  534  moving away from the base  74  and the second or upper lever arm  538  moving toward the base  74 , which as previously discussed may be an end cap. The biasing face  550  of the shift arm  486  contacts the biasing surface  506  of the lock arm  490 , which in turn causes the lock arm  490  to pivot away from and disengage the ring gear  294 . During this operation, the operator may feel and/or hear a click as the ring gear  294  is released, which may correspond to the biasing face  550  and/or the terminal end  558  of the shift arm  486  surpassing a detent  514  on the lock arm  490 . The amount of operating element  46  motion needed to switch modes of the operating system  70  may be negligible. 
     Once the lock arm  490  is disengaged from the ring gear  294 , the fixed orientation of the roller  42  may be released, allowing the shade material  22  to unwind and lower by gravity or any other downward biasing element (such as a supplemental spring), for example. The detent  514  associated with the interface of the shift arm  486  and the lock arm  490  maintains the actuator mechanism  86  in the shade extension mode, allowing the operator to release the operating element  46  and no longer monitor the covering  10  as the shade  22  is lowering. Generally, the shade  22  will lower regardless of the operating element  46  handling nuances of the operator, such as holding or releasing the operating element  46 . To stop the extension or lowering of the shade  22 , the operator may shift the operating system  70  into a retraction mode by pulling vertically downward on the operating element  46 , for example. With reference to  FIG.  16 B , the downward motion of the operating element  46  pivots or rotates the shift arm  486  about the cross pin  190  in the second direction  566 , as the operating element  46  is routed through the operating element conduit  162 , which resides in the same general vertical plane as the pivot pin  190  (see  FIG.  4 A ). The roller  42  or operating system  70  may include any suitable speed governing device to regulate the downward speed of the shade  22 . 
     With reference to  FIGS.  25 ,  26 A, and  26 B , another example of an operating system  1070  is provided. The operating system  1070  generally has the same features and operation as the operating system  70  previously described with the exception of the clutch element  274  and the actuator mechanism  86 . Accordingly, the preceding discussion of the features and operation of the operating system  70 , as depicted in  FIGS.  1 - 24   , should be considered equally applicable to the operating system  1070  depicted in  FIGS.  25 ,  26 A, and  26 B , except as noted in the following discussion pertaining to the wrap springs  1282  and the actuator mechanism  1086 . The reference numerals used in  FIGS.  25 ,  26 A, and  26 B  correspond to the reference numbers used in  FIGS.  1 - 24    to reflect the similar parts and components, except the reference numerals have been incremented by one-thousand. 
     As shown in  FIGS.  25  through  26 B , the operating system  1070  may include a transmission  1082  having a sun gear  1286 , a plurality of planet gears  1290 , and an annulus or ring gear  1294 . Similar to the operating system  70  previously discussed, the operating system  1070  includes a wrap spring  1282 A coupled to the sun gear  1286  and having an interference fit between the inner diameter of the wrap spring  1282 A and the outer diameter of the stationary axle  1278 . The wrap spring  1282 A rotationally slips around the axle  1278  in one direction to permit retraction of the shade, but locks around the axle  1278  in the other direction to prevent unwarranted extension of the shade. In contrast to the operating system  70 , the operating system  1070  replaces the clutch element  274  with a second wrap spring  1282 B having an interference fit between the outer diameter of the wrap spring  1282 B and the inner diameter of the sun gear  1286 . The second wrap spring  1282 B includes a tang  1402  that is coupled to the spool  1194  so that rotation of the spool  1194  in a first, shade retraction direction is transmitted to the sun gear  1286  and rotation of the spool  1194  in a second, shade extension direction is not transmitted to the sun gear  1286 . Thus, similar to the operating system  70  previously discussed, the operating system  1070  selectively transfers torque from the drive mechanism to the transmission in a first direction that retracts the shade but not in a second direction that extends the shade. Further, the operating system  1070  includes a brake element that maintains the shade in a desired position until an operator shifts the operating system  1070  into an extension mode. As shown in  FIG.  25   , the operating system  1070  may include an optional cover  1602 , which may be snap-fit onto a proximal side of the base  1074 . 
     With reference to  FIGS.  26 A and  26 B , the operating system  1070  also includes an actuator or shift mechanism  1086 . As shown in  FIG.  26 A , the actuator mechanism  1086  is in an extension mode in which the shift arm  1486  has pivoted the lock arm  1490  out of engagement with the outer teeth  1474  of the ring gear  1294 , thereby permitting the shade to extend across an associated architectural opening. A detent  1514  located on the lock arm  1490  holds the shift arm  1486  in the extension mode until a lateral force is applied to the shift arm  1486  through the eyelet, for example. As shown in  FIG.  26 B , the actuator mechanism  1086  is in a retraction mode in which an engagement tooth  1518  of the lock arm  1490  is engaged with the external teeth  1474  of the ring gear  1294 , thereby preventing rotation of the ring gear  1294  relative to the base  1074  and preventing extension of the shade. Similar to the actuator mechanism  86  previously discussed, the lock arm  1490  is biased into the engaged position or retraction mode with a biasing element. However, the actuator mechanism  1086  employs an extension spring  1524 , rather than the compression spring  524  discussed in relation to the actuator mechanism  86 . As can be appreciated, any suitable type of biasing element may be used in either example operating system. Although the shape of the shift arm  1486  and the lock arm  1490  are different than the shift arm  486  and the lock arm  490  previously discussed, the shift arm  1486  and the lock arm  1490  generally include the same features and function similarly as the shift arm  486  and the lock arm  490 . 
     The foregoing description has broad application. For example, while the provided examples include a transmission having a planetary gear set, it should be appreciated that the concepts disclosed herein may equally apply to any type of transmission, regardless of whether the transmission includes a gear reduction. For instance, some transmissions used by the operating system may not include a planetary gear set, such as in applications for small sized window coverings. Thus, it should be appreciated that the actuator mechanism may engage any type of transmission device. Further, the input and output components of the planetary gear set may vary depending on the window covering application. Moreover, although wrap springs and one type of clutch element have been discussed, other suitable brake and/or clutch elements may be used. Additionally, the example operating system may be used with any type of shade, including, but not limited to, roller and stackable shades. Furthermore, the example operating module or system may be used in association with either end of a head rail. For example, although the illustrated operating module may be configured for association with a right-hand side of a covering, an operating module configured for association with a left-hand side of the covering may be provided and may be a mirror image of the illustrated module. Accordingly, the discussion of any embodiment is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these examples. In other words, while illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art. 
     The foregoing discussion has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form or forms disclosed herein. For example, various features of the disclosure are grouped together in one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, it should be understood that various features of the certain aspects, embodiments, or configurations of the disclosure may be combined in alternate aspects, embodiments, or configurations. Moreover, the following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure. 
     The phrases “at least one”, “one or more”, and “and/or”, as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. 
     The term “a” or “an” entity, as used herein, refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. 
     The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Accordingly, the terms “including,” “comprising,” or “having” and variations thereof are open-ended expressions and can be used interchangeably herein. 
     All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader&#39;s understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of this disclosure. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. Identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to connote importance or priority, but are used to distinguish one feature from another. The drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the drawings attached hereto may vary.