Abstract:
The present invention provides a cervical collar with a rack and pinion adjustment mechanism. The rack moves a chin support member, which raises and lowers a chin piece. Independently, the present invention provides methods and mechanisms in which the chin support can angulate independently of the collar body. Such angulation is preferably accomplish by pivotally supporting the chin piece on the racks, or on the left and right chin support pieces. Thus, in a preferred class of embodiments, the collar has a pivot for the chin support pieces relative to the collar body, and an other pivot for the chin piece relative to the chin support pieces.

Description:
FIELD OF THE INVENTION 
   The field of the invention is cervical collars. 
   BACKGROUND OF THE INVENTION 
   Cervical collars are generally used to maintain a spine in neutral alignment. In order to maintain neutral alignment, the user&#39;s chin must be supported at a particular position. Because of this requirement for neutral alignment, and because users of the collars are proportioned differently, collars are made in various sizes. One of the problems with making collars in various sizes, however, is that medical practitioners have to stock and keep track of a multitude of sizes, which can become quite burdensome. 
   In order to address the burden caused by the need to stock various sizes, adjustable collars have emerged. One more recent patent, U.S. Pat. No. 6,663,581 to Calabrese, teaches a collar that can be adjusted by manually sliding a mandible into position and then inserting a clip to lock it. While the Calabrese collar may have addressed the adjustability problem with a modicum of success, there are still problems with the way the adjustment is done. One problem is that previously known adjustable collars have independently adjusted left and rights sides, which allows for asymmetric adjustments. Another problem is that making left and right adjustments requires two adjustments rather than one. Still a third problem is that failure of the adjustment on a single side to hold in position may result in a significant torquing of the head and lead to significant misalignment of the cervical spine. 
   A separate set of problems with respect to prior art cervical braces is that the chin support piece is rigidly coupled to the collar body, and does not sufficiently allow for different shaped chins. The result is that a wearer can experience excessive pressure at localized regions of the chin. This is not so much of a problem for an emergency collar, but it a very significant problem for a collar intended for extended wear. 
   Thus, there is a need for an adjustable collar where left and rights sides can be adjusted with a single motion, and that provides a chin support that can angulate independently of the collar body. 
   SUMMARY OF THE INVENTION 
   The present invention provides methods and mechanisms in which left and rights sides can be adjusted with a single motion. Adjustment of the left and rights sides can be advantageously accomplished using a gear mechanism, and in particular a rack and pinion mechanism. As the pinion is rotated, the chin support member is raised or lowered as a result of movement of the racks. 
   Independently, the present invention provides methods and mechanisms in which the chin support can angulate independently of the collar body. Such angulation is preferably accomplish by pivotally supporting the chin piece on the racks, or on the left and right chin support pieces. Thus, in a preferred class of embodiments, the collar has a pivot for the chin support pieces relative to the collar body, and an other pivot for the chin piece relative to the chin support pieces. 
   Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  is a front perspective view of a cervical collar. 
       FIG. 2  is a front view of the cervical collar of  FIG. 1 , with the cover removed. 
       FIG. 3  is an exploded perspective view of a cervical collar of  FIG. 1 . 
       FIG. 4  is a perspective view of an alternative cervical collar utilizing a single rack. 
   

   DETAILED DESCRIPTION 
   Referring first to  FIGS. 1-4 , a cervical collar  100  comprises a main collar body  110 , mechanism enclosure  111 , a knob  120 , a first rack  130 , a second rack  140 , a first chin support member  135 , a second chin support member  145 , and a chin piece  150 . 
   First and second racks  130 ,  140  and the pinion gear  310  cooperate to adjust the height of the first and second chin support member  135 .  145 , and thereby the height of the chin piece  150 . These parts are configured to allow use of a single (or relatively small number of collars) to maintain the head and neck in neutral alignment, supports must be consistent with the key dimension of an individual wearer. As used herein, the term “key dimension” means the height of the inferior surface of the chin where the chin piece supports the chin, relative to a horizontal line drawn at the top of the shoulder where the collar body rests upon the trapezius muscles. 
   As best seen in  FIG. 1 , the racks  130 ,  140  are guided between the main collar body  110  and mechanism retainer  370  toward the pinion gear  310 . The pins  132  and  142  couple the racks to the chin support members  135  and  145  such that upward movement of a rack causes the associated chin support member to also move upward. Likewise, downward movement of a rack will cause the associated chin support member to move downward. Because the racks  130 ,  140  are used to push the chin support members  135 ,  145  upward relative to collar body  110  (and of course also relative to the wearer&#39;s sternum and shoulders), they are preferably made of a sufficiently stiff material. Contemplated materials include hard thermoplastic, metal, etc. 
   Pinion gear  310  is preferably constructed from a relatively hard plastic or other suitable material that exhibits relatively little wear over time due to contact with the rack teeth (e.g. acetyl resin). The teeth of the pinion gear must of course mate with the teeth of the racks. 
   In the embodiment of  FIGS. 1-4 , the height adjustment is accomplished by rotating knob  120 , which causes rotation of a pinion gear (see  310  in  FIG. 3 ), which moves the racks  130 ,  140  laterally and vertically, which causes the first and second chin support members  135 ,  145  to move up and down. Rotation of the knob  120 , and hence of the gear  310 , is preferably bi-directional with one direction (e.g. clockwise) causing the racks  130 ,  140  to move upward and he other (e.g. counter-clockwise) causing the racks to move downward. 
   Since the pinion gear  310  operates upon both racks  130 ,  140  simultaneously, each chin support member  135 ,  145  moves up or down at the same time, at the same rate, and for the same distance. Preferred embodiments include some mechanism for limiting the travel of the racks  130 ,  140  and support members  135 ,  145 . This can be accomplished in several ways. For example, travel of the racks  130 ,  140  can be readily limited by limiting rotation of the pinion gear  310 , through the use of stops, by limiting the number of teeth on one or both of the racks  130 ,  140 , and/or limiting the rise of the chin support member  135 ,  145  such as through the use of a pin within a slot.  FIGS. 1 and 2  show the use of pins  132 ,  142  cooperation with slots  160 ,  170  for this purpose. Slots  160  and  170  allow the support members  135 ,  145  to move from a fully extended configuration in which the pins  132 ,  142  are at their highest point to a fully compressed configuration in which the pins  132 ,  142  are at their lowest point. The fully extended configuration is intended to adapt to a person with a large key dimension (tall neck), while the most compressed configuration is intended to adapt to a person with an especially small key dimension (short neck). 
   It should also be appreciated that the extent of pivoting of the chin piece  150  should probably be limited in some manner to prevent excessive angulation that could result in the wearer&#39;s chin sliding off the chin piece. Such limitation can be provided by the shapes of the juxtaposing surfaces of the chine piece  150  and the side pieces  135 ,  145 . 
   Preferred embodiments of collar  100  can be readily sized to a wearer by including calibration markings  190  that correspond to key dimensions. For example, a calibration marking for a “short” collar might correspond to a key dimension of 0.75. The calibration can be in a relatively small unit of measure such as a millimeter but is more likely to be in centimeters, inches or some other designation. Placement of the calibration markings  190  should be conspicuous to the person setting the size (generally not the user himself). In  FIG. 1 , for example, the calibration markings  190  are shown on the side of the collar body. In other embodiments, the calibration may be on or around the knob or some other place along the path of either rack. 
   Knob  120  not only rotates, but also move in and out. In the fully inward configuration the knob is locked from rotation, and in the outward configuration the knob  120  is rotatable (unlocked). In the particular embodiments shown, the pinion gear  310  is directly connected to the knob  120 , and the knob  120  is biased to the locked (inward) position. 
   A safety  180 , comprising lock  182  and spring  184 , can optionally be provided as a secondary means of prohibiting movement of the racks. Safety  180  can operate in any suitable fashion, but in this particular embodiment the safety  180  prevents the knob  120  from moving to the outward (rotatable) position. This may be done by providing a tab on the pinion gear which can be stopped by contact with the safety. 
   Chin support members  135  and  145  are pivotally mounted to the main collar body  110  at points  112  and  114 . Additionally, chin piece  150  is pivotally mounted to the chin support members  135  and  145  at pivots  137 ,  147 . As used herein the term pivot includes mechanisms that provide pivoting motion, even though there is no actual axle or line about which the pivoting motion takes place. Thus, chin piece  150  can be said to be pivotally mounted to the chin support members  135  and  145  at pivots  137 ,  147  even in situations where these parts are molded together in a manner that provides sufficient “play” to effectively provide a pivoting type motion. 
   An alternative embodiment of a cervical collar  400  is shown in  FIG. 4 . The collar  400  has a single central rack  405  and a pinion gear  410  attached to main collar body  415 . Rotation of the pinion gear  410  moves rack  405  upward, which therefore raises chin piece  450 . As with the embodiment of  FIGS. 1-3 , the height of the chin piece  450  can be adjusted by rotating a knob  420 , which turns the pinion gear  410 . In this embodiment, however, there is no need to pull out the knob. 
   It should also be appreciated that the terms “rack” and “pinion” are used herein in a broader manner than ordinary usage, and include embodiments with teeth of any size, or indeed no teeth at all. In the latter case, for example, the rack and pinion can each have rubbery surface that together provide sufficient friction to couple the relatively motions of the rack and pinion. Moreover, in common usage one often refers to the rack portion of a rack and pinion as being flat. As used in this application, a rack need not be flat, and indeed in most instances will be curved. The only essential feature of the racks and pinions as used herein is that the rack translates in space as the pinion rotates. Where discussion is limited to a toothed rack and pinion, either the teeth are expressly stated, or the pinion is referred to as a pinion gear. 
   Thus, specific embodiments and applications of a cervical collar with a geared adjustment have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.