Patent Publication Number: US-9421119-B2

Title: Cervical collar brace with cable adjustment

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of U.S. Non-Provisional patent application Ser. No. 13/683,528, now U.S. Pat. No. 8,740,830 filed Nov. 21, 2012, and which application is hereby incorporated herein by reference, and which application is a continuation-in-part application of U.S. Non-Provisional patent application Ser. No. 13/451,704, now U.S. Pat. No. 8,864,693 filed on Apr. 20, 2012, and which is also hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention related to an orthopedic brace and in particular relates to cervical collar. 
     SUMMARY OF THE INVENTION 
     Briefly described, in a preferred form, the present invention comprises a cervical collar brace including a main body collar, a first chin side support pivotally mounted relative to the main body collar, and a second chin side support pivotally mounted relative to the main body collar. A cable adjuster is provided for adjustably securing the first and second chin side supports to the main body collar, with the cable adjuster including a rotatable wheel, one or more cables secured to the rotatable wheel, and one or more lift effectors coupled to the first and second chin side supports for lifting the chin side supports in response to rotation of the rotatable wheel in a first rotation direction. A chin piece is provided for supporting a wearer&#39;s chin and in turn is supported by the chin side supports. Preferably, the one or more cables are guided for lifting the chin side supports with the use of a capstan and cable guide tubes. 
     Optionally, the capstans can be in the form of rotating pulleys. Alternatively, the capstans can be fixed pivot pins, if desired. For Also preferably, the one or more cables comprise two cables, one for each chin side support. Alternatively, a single continuous cable can be employed to operate both chin side supports. 
     Optionally, the cervical collar brace also includes a biasing member for biasing the first and second chin side supports toward a lowered position and wherein the cable adjuster is operable for raising the chin side supports against the biasing of the biasing member. Preferably, the biasing member comprises one or more resilient rubber bands. 
     In one form the cable adjuster does not restrict the position of the chin side supports to discrete positions relative to the main body collar, but instead is infinitely variable within a range of motion. In another form the cable adjuster restricts the position of the chin side supports to discrete positions relative to the main body collar. In this regard, the rotatable wheel can be secured in discrete positions by hard stops. 
     Preferably, the one or more cables is/are guided within guide elements formed in or secured to the main body collar. In one preferred form, the guide elements guide one end of the one or more cables through an upper opening through which the cable can be partially drawn to raise the chin side supports relative to the main body collar. 
     These and other features and advantages of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         FIG. 1  is a perspective view of a cervical collar brace according to a first example embodiment of the invention. 
         FIG. 2  is a partially exploded perspective view of the orthopedic brace of  FIG. 1 . 
         FIG. 3  is a perspective view of another cervical collar brace according to a second example embodiment of the present invention. 
         FIG. 4  is a partially exploded perspective view of a portion of the orthopedic brace of  FIG. 3 . 
         FIG. 5  is a partially exploded perspective view of a portion of the orthopedic brace of  FIG. 3 . 
         FIG. 6  is a partially cut-away, perspective view of a portion of the orthopedic brace of  FIG. 3  according to a third example embodiment of the present invention. 
         FIG. 7A  is a perspective view of a portion of the orthopedic brace of  FIG. 3 , wherein the support arm is fully lifted. 
         FIG. 7B  is a perspective view of a portion of the orthopedic brace of  FIG. 3 , wherein the support arm is fully lowered. 
         FIG. 8  is a perspective view of a portion of the cable adjuster of the orthopedic brace of  FIG. 3  according to a fourth example embodiment of the present invention. 
         FIG. 9  is a perspective view of a portion of the cable adjuster of the orthopedic brace of  FIG. 3  according to a fifth example embodiment of the present invention. 
         FIG. 10  is a right side perspective view of a cervical collar brace according to a sixth example embodiment of the invention. 
         FIG. 11  is a left side perspective view of the orthopedic brace of  FIG. 10 . 
         FIG. 12  is a close up perspective view of a portion of the orthopedic brace of  FIG. 10 . 
         FIG. 13  is a close up perspective view of a portion of the orthopedic brace of  FIG. 10 , showing the connection of cables with the rotatable wheel. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawing figures, in which like reference numbers refer to like parts throughout the several views, preferred forms of the present invention will now be described by way of example embodiments. It is to be understood that the embodiments described and depicted herein are only selected examples of the many and various forms that the present invention may take, and that these examples are not intended to be exhaustive or limiting of the claimed invention. Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. 
     With reference now to the drawing figures, wherein like reference numbers represent like parts throughout the several views,  FIGS. 1-3  show a cervical collar brace  10  according to a first example embodiment of the present invention. In example embodiments, the cervical collar  10  includes a main collar body  20 , a first chin support member  30 , a second chin support member  40 , a chin piece  50 , and a cable adjuster  60 . Typically, the first and second chin supports  30  and  40  pivotally mount to the main collar body  20 , and the chin piece  50  pivotally mounts to the first and second chin supports  30 ,  40 . Thus, the chin supports  30  and  40  can pivot relative to the main collar body  20  and the chin piece  50  can pivot relative to the chin supports  30  and  40 . The cable adjuster  60  is partially housed within the main collar body  20  and adjustably secures the chin supports  30  and  40  to the main collar body  20 . With a single motion of the cable adjuster  60 , the chin supports  30  and  40  pivot relative to the main collar body  20 , thereby lifting or lowering the pivotally-mounted chin piece  50  to support a wearer&#39;s chin. Those skilled in the art will understand that the cervical collar  10  can be made in a variety of sizes and shapes so as to accommodate users of various body sizes. 
     The main collar body  20  generally comprises a “U-shaped” member having a first (closed) end  21  for placement against a wearer&#39;s neck or chest region and a second (open) end  22  for wrapping around the sides of a wearer&#39;s neck or head. In typical embodiments, the main collar body  20  has one or more holes, pins, slots or other mounting elements to accommodate mounting or cooperating elements of the collar brace  10 . In example embodiments, the first end  21  includes an orifice or aperture  25  formed therein to receive a portion of the cable adjuster  60 . The second end  22  includes a first arm  23  and a second arm  24  generally shaped for placement against a wearer&#39;s shoulders. Each arm  23 ,  24  is pivotally mounted to the chin side supports  30 ,  40 . In one form, the pivotal connection is formed by a pivot hole formed in the chin supports  30 ,  40  and in the arms  23 ,  24 , with pivot pins  33 ,  43  received in the pivot holes. Also, first slots  122 ,  142  are formed in the main collar body  20  for accompanying the cable adjuster  60 . Optionally, one or more channels, pathways, and/or conduits can be mounted to, within, or partially within the main collar body  20  for guiding a portion of the cable adjuster  60 . 
     The chin supports  30 ,  40  are generally elongate members having a first end  32 ,  42  and a second end  34 ,  44  generally opposite thereto. In example embodiments, the chin supports  30 ,  40  are mirror images of one another. The first ends  32 ,  42  of the chin supports  30 ,  40  have pivot holes  36 ,  46  to assist in pivotally mounting the same to the pivot holes of the first and second arms  23 ,  24 . The second ends  34 ,  44  of the chin supports  30 ,  40  have mounting holes  38 ,  48  to assist in pivotally mounting the chin piece  50  thereto. Further, the chin supports  30 ,  40  include second slots  124 ,  144  formed therein between the first and second ends for accompanying the cable adjuster  60 . Preferably, the first end  32  of the first chin support  30  pivotally mounts to the first arm  23  and the first end  42  of the second chin support  40  pivotally mounts to the second arm  24 . Various types of pins, screws, clips or other fasteners can be used to pivotally secure the members together. In preferred embodiments, the second ends  34 ,  44  of the pivotally mounted chin supports  30 ,  40  generally extend towards the first end  21  of the main collar body  20 . In additional example embodiments, one or more channels and/or pathways can be mounted to, within, or partially within the chin supports  30 ,  40  for guiding a portion of the cable adjuster  60 . 
     The chin piece  50  is a delta-shaped member having a first end  52  and second end  54  generally opposite thereto. The first and second ends  52 ,  54  have mounting holes to assist in pivotally mounting the same to the second end mounting holes  38 ,  48  of the chin supports  30 ,  40 . Preferably, one or more pins, screws, clips, or other fasteners pivotally mount the first end  52  mounting hole of the chin piece  50  to the second end mounting hole  38  of the first chin support  30  and the second end  54  mounting hole of the chin piece  50  to the second end mounting hole  48  of the second chin support  40 . 
     The cable adjuster  60  generally includes a rotatable wheel  70 , a knob  80 , a plurality of mating or catching surfaces  90 , cables  100  and  102 , and first and second lift effectors  120 ,  140 . In typical embodiments, the rotatable wheel  70  has two cables  100 ,  102  mounted thereto and pivotally mounts within the aperture  25 . In one example, one cable having a sufficient length to reach both lift effectors  120 ,  140  is mounted to the rotatable wheel  70  at its midpoint. Alternatively, two cables  100 ,  102  can each be attached to the rotatable wheel  70  and respective lift effectors  120 ,  140 . Free ends of the cables extend to each arm  23 ,  24  or each chin support  30 ,  40  where they are mounted to pins  126 ,  146  for slidably coupling the first slots  122 ,  142  to the second slots  124 ,  144 . Preferably, the pins  126 ,  146  are permitted to travel within the slots wherein rotation of the rotatable wheel  70  causes the pins  126 ,  146  to lift the second ends of the pivotally-mounted chin supports  30 ,  40  relative to the main collar body  20 . 
     Optionally, the cervical collar  10  can include a posterior member or rear head support  54  for placing against a wearer&#39;s rear neck or head (see  FIG. 3 ). Preferably one or more apertures are formed therein to receive a hook or loop material to be removably mounted or secured to a hook or loop material on the collar  10 . Further, the first end of the main body collar  20  can include an integral or removably mounted skirt-like flange  56  for additional cushioning support to a wearer&#39;s neck or chest region. 
       FIG. 4  shows a portion of the cable adjuster  60  according to a second example embodiment. In general, one or more biasing springs can be mounted within the orifice  25  of the main body collar  20  to control the behavior of the rotatable wheel  70  and one or more elements of the cable adjuster  60  can include mating or catching surfaces to secure the rotatable wheel  70  to particular discrete positions. In typical embodiments, the orifice  25  includes a first end  26  and a second end  27 . Optionally, instead of using hand catches to provide discrete stops, one can use smooth friction surfaces to provide infinitely variable positioning. The first end  26  includes one or more catching surfaces or detents  90  surrounding a central opening and the second end  27  includes an opening sized to receive the rotatable wheel  70 . Preferably, the opening of the second end  27  is larger than the opening of the first end  26 . In additional example embodiments, the orifice  25  can have a substantially similar first and second side and a separate fitting can be used to form one or more catching surfaces or detents  90  (see  FIG. 2 ). 
     In example embodiments, the rotatable wheel  70  is housed within the second end of the orifice  25  and mounts to a knob  80  positioned close to the first end  26 . The knob  80  includes a grasping area to permit a wearer or user to rotate the rotatable wheel  70 , indents or catching surfaces to mate with the detents  90  of the first end  26 , a central shaft to couple to the rotatable wheel  70 , and a bore within the knob to receive a screw or fastener. Preferably, the central shaft of the knob  80  extends through the central opening of the first end  26  of the orifice  25  and mounts within a recessed portion of the rotatable wheel  70 . Generally, the central shaft of the knob  80  and the recessed portion of the rotatable wheel  70  have a substantially similar contour to engage and couple to one another. Preferably, the rotatable wheel is secured in discrete positions by the catching surfaces or hard stops. This can be selected by pulling the knob  80  away from the orifice  25 , thereby removing the indents from the detents  90 , turning the knob to the desired position while remaining disengaged from the detents, and then returning the knob  80  to its unpulled state. Those skilled in the art will further understand that a mechanism permitting the rotatable wheel  70  to be secured in infinitely variable positions (for example a rotatable disc and a selective brake to lock at a desired position) can be used and still be within the scope of the invention. 
     Additionally, a coil spring  72  can be positioned between the pivotally mounted rotatable wheel  70  and knob  80 . Preferably, the coil spring  72  is housed within the second end  27  of the orifice  25  and biases the knob  80  towards the second end  27 , thereby preventing the rotatable wheel  70  from rotating by forcing the catching surfaces of the knob  80  and first end  26  of the orifice  25  to engage each other. When it is desired to reposition the rotatable wheel  70 , the knob  80  can be pulled away from the orifice and rotated. Optionally, a screw or fastener  74  can be used to further secure the rotatable wheel  70  to the knob  80  and prevent the bias of the coil spring  72  from decoupling the two. 
     Moreover, a spiral-like torsion spring  75  can couple to the rotatable wheel  70  to bias the wheel towards an unwound position. As depicted in  FIGS. 4-6 , the torsion spring  75  is housed within a portion of the rotatable wheel  70  and secured by a cap  76 . The cap  76  generally includes a central shaft to couple to a central portion of the torsion spring  75  and a perimeter flange to mount to the second end  27  of the orifice  25 . For example, as the rotatable wheel  70  is rotated in a first direction, the central shaft of the cap  76  remains stationary, preventing the central portion of the torsion spring from rotating with the rotatable wheel  70 , and the outer perimeter of the torsion spring is forced to rotate with the rotatable wheel  70 . When the unwound position is desired, the mating surfaces of the orifice first end  26  and the knob  80  are disengaged from one another, and while the mating surfaces remain disengaged by continuously overcoming the bias of the coil spring  72 , the knob  80  and coupled rotatable wheel  70  can be easily turned to an unwound position by the bias of the torsion spring  75 . 
       FIG. 6  shows a partial cut-away view of a portion of the cable adjuster  60  according to a third example embodiment. In general, the portion of the cable adjuster  60  includes the orifice  25  comprising one or more detents  90 . The rotatable wheel  70  is housed within the second end  27  and coupled to the central shaft of the knob  80 . The torsion spring  75  is housed within a portion of the rotatable wheel  70 , and the cap  76  encloses the second end  27  and couples to the central portion of the torsion spring  75 . In this configuration, the coil spring  72  is removed between the rotatable wheel  70  and the knob  80  wherein the rotatable wheel  70  can be unwound by removing the indents of the knob  80  from the detents  90  a first time. When the original unwound position is desired, the indents of the knob  80  are disengaged from the detents  90  and the knob  80  and the coupled rotatable wheel  70  is freely biased to an unwound position. 
       FIGS. 7A-B  show perspective views of the first lift effector  120  including a portion of the main body collar  20  and the pivotally mounted first chin side support  30 . As described herein, the first and second lift effectors  120 ,  140  are mirror images of one another and thus only lift effector  120  will be discussed. Since the cable winding or unwinding around the rotatable wheel  70  actuates both the first and second lift effectors  120 ,  140 , the first and second chin supports  30 ,  40  move up or down at the same time, at the same rate, and for the same distance. The lift effector  120  includes the first slot  122  formed within the first arm  23  of the main body collar  20 , the second slot  124  formed within the first chin side support  30 , the pin  126  coupling the slots  122 ,  124  together, and a cable  100  having a first end mounted to the rotatable wheel  70  and a second end mounted to the pin  126 . From a lowered position (rotatable wheel unwound), the pin  126  is driven within the first slot  122  by turning the rotatable wheel  70  (see  FIG. 7B ). Subsequently, as the pin  126  is forced to travel within the first slot  122 , the second slot  124  is forced to adjust accordingly, thereby lifting the pivotally mounted chin support  30  (see  FIG. 7A ). Those skilled in the art will further understand that slots of a variety of shapes, sizes or configurations can be used and still be within the scope of the invention. Those skilled in the art will further understand that pins of many shapes, sizes, forms, configurations or frictional-fits can be used and still be within the scope of the invention. 
     Optionally, the slots can include one or more catching surfaces or indents to interact with a portion of the cable adjuster  60 , for example to maintain a particular position of the chin supports  30 ,  40  if the catching surfaces or indents  90  of the cable adjuster  60  were released unintentionally, permitting the rotatable wheel  70  to unwind. 
       FIG. 8  shows a perspective view of a portion of the first lift effector  120  according to a fourth example embodiment. As described herein, the first and second lift effectors  120 ,  140  are mirror images of one another and thus only lift effector  120  will be discussed. In example embodiments, the cord  100  is guided from the rotatable wheel  70  to a top portion of the first slot  122  through a conduit or tube  104 , for example like a Bowden cable used to operate a bicycle braking system. The tube  104  can be mounted to, within, or partially within the main collar body  20 . Further, the cord extends within or near the slot  122  and mounts to the pin  126 . The cord  100  can be mounted to the pin by tying a knot, a loop, a looped or notched member within or extending from the pin  126 , or by any other connector. As the rotatable wheel  70  is turned, the cable  100  is drawn and raises the pin  126 , further raising the chin support  30  (see  FIG. 7A ). 
     In additional example embodiments, the lift effectors  120 ,  140  can include one or more biasing members for biasing the first and second chin supports  30 ,  40  towards a lowered position. As depicted in  FIG. 8 , a biasing member or resilient rubber band  128  is mounted to the pin  126  at a first end and to a post  130  at a second end. The biasing member  128  biases the pin  126  towards a bottom portion of the slot  122 , thereby biasing the pivotally mounted first chin support  30  toward a lowered position. Preferably, the bias of the biasing member  128  is adjusted to permit the cable adjuster  60  to operate. Those skilled in the art will understand that one or more gears could be used to reduce the rotational force required to overcome the bias of the biasing member  128 . 
       FIG. 9  shows a perspective view of a portion of the first lift effector  120  according to a fifth example embodiment. In example embodiments, the cord  100  is guided from the rotatable wheel  70  to a generally central portion of the first arm  23  through a conduit or tube  204 , for example a Bowden cable. Further, the cord extends from the end of the generally centrally-positioned tube  204  and passes around one or more structures or connectors before mounting to the pin  126 . For example, the cord  100  passes around a first post  230  and under a second post  232  (generally forming a backwards “S” shape), and further passes over a third post  234  close to the top portion of the slot  122  before mounting to the pin  126 . Preferably, the posts have one or more apertures to thread and guide the cord  100  therethrough. Additionally, the cord  100  can be mounted to the pin by tying a knot, a loop, a looped or notched member within or extending from the pin  126 , or by any other connector. Similarly, as the rotatable wheel  70  is turned, the cable  100  is drawn and raises the pin  126 , further raising the chin support  30  (see  FIG. 7A ). Those skilled in the art will understand that one or more pulleys, guides, or friction-reducing elements can be used and still be within the scope of the invention. 
     In additional example embodiments, the cable  100  can further extend to the second slots  124 ,  144  of the first and second lift effectors  120 ,  140 . In example embodiments, the cable  100  can be guided close to the second slots  124 ,  144  through a tube (e.g., like tube  104  or  204 ). In this manner, by turning the rotatable wheel  70 , the pin (e.g., like pin  126 ,  146 ) is forced to travel within the second slots  124 ,  144 , and the first slots  122 ,  142  are forced to adjust accordingly. Additionally, the cable  100  can be guided through the pivots where the first and second chin supports  30 ,  40  are mounted to the arms  23 ,  24  of the main collar body  20 . 
     In commercial embodiments, the elements of the cervical collar  10  are generally made of a plastic (e.g., polyethylene, thermoplastic, etc.) or other materials transparent to X-Ray, computed tomography, and magnetic resonance imaging. The cervical collar  10  can also include one or more removable pads for additional comfort and support to a wearer or user. Preferably, the removable pads are made of a laminated foam material or a material suitable to wick away moisture and to reduce skin irritation. In example embodiments, one side of the removable pads comprises a loop material (or fabric having a weave that cooperates with hook material) and one side comprises a material suitable to be placed against the skin of a user or wearer. Any portion of the main collar body  20 , first or second chin support  30 ,  40 , chin piece  50 , optional rear head support  54 , and/or optional flange  56  can include hook material for cooperating with the loop material of the one or more removable pads. 
       FIGS. 10-12  show a cervical collar brace  610  according to a sixth example embodiment of the present invention. The cervical collar  610  includes a main collar body  620 , a first chin support member  630 , a second chin support member  640 , a chin piece  650 , and a cable adjuster  660 . The first and second chin supports  630  and  640  are pivotally mounted relative to the main collar body  620 , and the chin piece  650  is pivotally mounted relative to the first and second chin supports  630 ,  640 . Thus, the chin supports  630  and  640  can pivot relative to the main collar body  620  and the chin piece  650  can pivot relative to the chin supports  630  and  640 . 
     The cable adjuster  660  is mounted to the main collar body  620  and adjustably secures the chin supports  630  and  640  to the main collar body  620 . With a single motion of the cable adjuster  660 , the chin supports  630  and  640  pivot relative to the main collar body  620 , thereby lifting or lowering the pivotally-mounted chin piece  650  to support a wearer&#39;s chin. The cable adjuster  660  includes a rotatable wheel  670  or knob and a pair of cables  680 ,  690  secured to the rotatable wheel  670 . 
     A pair of lift effectors  710 ,  715  are coupled to the first and second chin side supports for lifting or lowering the chin side supports in response to rotation of the rotatable wheel  670 . Two capstans  720 ,  725  are positioned above the lift effectors  710 ,  715  for reversing a movement of the ends of the cables. In this example embodiment, the capstans comprise rotatable pulleys. Alternatively, the capstans can comprise fixed pins over which the cables are looped for sliding motion. 
     The two cables  680 ,  690  each include first and second end portions, with the first end portion secured to a lift effector for pulling the lift effector in one direction and the second portion secured to the lift effector for pulling the lift effector in a second direction, opposite to the first direction. For example, as shown in  FIG. 10 , the single cable  690  has a first end  691  for lifting the lift effector and a second end  692  for pulling the lift effector downwardly. Optionally, the cables run in fixed tubes (secured to the collar body  620 ) to keep the cables reasonably taut and allow movement of the cables to be turned into movement of the lift effectors (by preventing the cables from assuming a different overall shape/orientation as they are pulled in one direction or another). See for example the fixed tubes  683 ,  684 ,  693 ,  694 . As mentioned above, these can be in the form of Bowden tubes. The tubes are secured at their ends to the main collar body  620 , such as by ferrules  686 ,  687 ,  696 ,  697 . 
     Preferably, each cable is arranged in a race-track configuration, and each cable includes first and second end portions, with the first portion secured to a lift effector for pulling the lift effector in one direction and the second portion secured to the lift effector for pulling the lift effector in a second direction, opposite to the first direction. Thus, preferably, each cable is a single cable and its two ends are each attached to the lift effector such that moving the race-track cable in one direction lifts the lift effector and moving the cable in the opposite direction lowers the lift effector (and thus the chin piece). Preferably, the rotatable wheel is connected to an internal axle and the cables are wrapped around the axle such that rotation of the rotatable wheel in one direction causes the cables to pull up on the lift effectors and rotation of the rotatable wheel in an opposite direction causes the cables to pull down on the lift effectors. 
       FIG. 12  shows the cable adjuster&#39;s rotatable wheel  670  in greater detail. As depicted in this figure, the wheel  670  has a knurled or serrated circumferential edge  671  and a toothed rear surface  672 . Those skilled in the art will recognize that the rotatable wheel or knob can take various forms/shapes for convenience, aesthetics, or ergonomics. The toothed rear surface carries a small number of radially projecting teeth on the annular rear surface  672 , such as teeth  673 ,  674 ,  675 ,  676 . These teeth are adapted to engage a circular array of teeth  665 . Thus, the cable adjuster is movable between various discrete positions, and thereby restricts the position of the chin side supports to discrete positions relative to the main body collar. 
     In other words, the rotatable wheel portion of the cable adjuster is secured in discrete positions by hard stops (the teeth). The rotatable wheel is secured in these discrete positions by hard stops which are selected by pulling out on the rotatable wheel and turning the rotatable wheel while it is pulled out and then returning the rotatable wheel to its unpulled state. Thus, the wheel can be pulled out along axis  668 , rotated about the axis  668  to achieve the desired adjustment in the height of the chin piece, and the wheel can be moved back into a locked position (with the teeth engaged with one another) by returning the wheel along axis  668 . Preferably, a spring is provided for biasing the wheel toward its retracted position in which the teeth  673 - 676  are engaged with the circular array of teeth  665 . 
       FIG. 13  shows the connection of the cables  680 ,  690  with the rotatable wheel  670  in greater detail. As depicted in this figure, an internal axle or drum  677  of the rotatable wheel  670  provides for the connection of the single cables  680 ,  690 . In one form, the single cables  680 ,  690  engage slots  679  formed along the periphery of the axle  677 . As such, the slots  679  ensure the cables  680 ,  690  remain engaged therewith such that motion of the rotatable wheel  670  causes movement of the ends  681 ,  682 ,  691 ,  692  of the cables  680 ,  690 . In other forms, the single cables  680 ,  690  may be cut or separated as desired, for example, wherein an end opposite of the end  691  is connected to one slot and wherein an end opposite the end  692  is connected to another slot of the axle  677 . In example forms, a knot or cord protrusion can be provided to ensure that the cords remain engaged with the slots  679 . Optionally, glues, adhesives or other forms of connecting or coupling additives can be used with the cables  680 ,  690  and slots  679  as desired. 
     In  FIGS. 10-13 , the collar is shown with an outer covering thereof removed, for clarity of illustration such that the cables and the tubes are depicted as mounted on an inside portion of the collar. In a commercial embodiment of this invention, it is expected that the tubes and cables will be covered with an outer covering. 
     Applicants have found that this embodiment of  FIGS. 10-13  provides an exceptionally smooth adjustment of the chin piece, while also providing secure positioning thereof. 
     While the invention has been described with reference to preferred and example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.