Abstract:
Neck brace that inhibits excessive neck movement during impact, yet allows for a high degree of movement of the wearer&#39;s head during normal operation of the neck brace. May include impact surface(s) that limits movement of a helmet by contacting an underside of the helmet; bearing surface(s) configured for bearing on wearer; a structure between impact surface and bearing surface, sufficiently resilient to transfer impact loads of the helmet to the impact surface, to the wearer&#39;s body; wherein the impact surface is displaceable towards an adjacent part of the bearing surface and wherein the structure is configured to permit the displacement at rates slower than a predetermined rate of displacement and to resist the displacement if the rate of displacement exceeds the predetermined rate. May include a pivotal joint between the displaceable part and remainder of neck brace and impact brake element(s).

Description:
[0001]    This application is continuation in part of U.S. Utility patent application Ser. No. 11/440,576 which is a national stage filing of international application PCT/ZA2004/000148 filed 26 Nov. 2004, published in English under PCT Article 21(2), which claims benefit from and is a Paris Convention filing of South African Patent Application Serial No. 2003/9174 filed 26 Nov. 2003, the specifications of which are all hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to protective equipment for inhibiting neck injuries while wearing a helmet. In particular, the invention relates to a neck brace. 
         [0004]    2. Description of the Related Art 
         [0005]    A device in the form of a neck brace is disclosed in International Patent Application No. PCT/ZA04/00148, which is intended to be worn around the neck and to receive impact loads from the bottom edge of a full face helmet and to transfer these loads to the wearer&#39;s body along a load path. The neck brace described in PCT/ZA04/00148 inhibits excessive movement of the helmet and thus of the wearer&#39;s head during impact, e.g. during a collision in motor sport. 
         [0006]    The neck brace described in PCT/ZA04/00148 was designed to inhibit head and neck movement as little as possible during normal operation and it has achieved that purpose. However, in some exceptional cases, notably in high speed road motorcycling, the wearer needs to tilt the head more severely during normal operation, typically to achieve higher aerodynamics. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    One or more embodiments of the invention inhibit excessive neck movement during impact, yet allow for a high degree of movement of the wearer&#39;s head during normal operation of the neck brace. 
         [0008]    According to the present invention there is provided a neck brace that includes:
       at least one impact surface which, when the brace is used with a helmet, limits movement of the helmet by contacting an underside of the helmet;   at least one bearing surface which is shaped and configured for bearing on the body of a wearer of the brace;   a structure that extends between the impact surface and the bearing surface, the structure being sufficiently resilient to transfer impact loads of the helmet on the impact surface, to the wearer&#39;s body; and,   wherein at least part of the impact surface is displaceable towards an adjacent part of the bearing surface and wherein the structure is configured to permit the displacement at rates slower than a predetermined rate of displacement and to resist the displacement if the rate of displacement exceeds the predetermined rate.       
 
         [0013]    The brace may include a pivotal joint between the displaceable part and the remainder of the neck brace and the pivotal joint may be configured to permit pivotal, as well as sliding displacement of the displaceable part relative to the remainder of the neck brace. 
         [0014]    The neck brace may include a rear displaceable part at the rear of the neck brace which is downwardly pivotable towards the upper back of a wearer of the neck brace and may include a front displaceable part at the front of the neck brace which is downwardly pivotable towards the chest of the wearer and which may be configured to slide rearwards towards the wearer&#39;s chest during the pivotal movement. 
         [0015]    The support structure may include at least one impact brake element extending between the displaceable part of the impact surface and the remainder of the structure. 
         [0016]    The impact brake element may include:
       a first component which defines a first brake surface;   a second component which defines a second brake surface and which is displaceable relative to the first component when the displaceable part is displaced relative to the neck brace, the first and second braking surfaces extending at an acute angle relative to each other;   at least one lock element disposed between the first and second brake surfaces; and,   the lock element being configured to allow movement between the first and second components at rates lower than a predetermined rate and to engage the first and second brake surfaces in a taper lock, when displacement between the two components occurs at a rate exceeding the predetermined rate.       
 
         [0021]    The first brake surface may be a cylindrical surface and the second brake surface may be a frusto-conical surface. The first component may be an outer cylindrical sleeve and the second component may be elongate in shape and may be longitudinally displaceable with at least part of the second component inside the sleeve, the second component including a protuberance that protrudes outside the sleeve, at least at times. An annular recess may be defined around the second component of at least one the lock element and the second brake surface may be defined on the inner circumference the annular recess and at least one, but preferably a plurality of lock elements are held captive inside the annular recess. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0022]    For a better understanding of the present invention, and to show how the same may be carried into effect, the invention will now be described by way of non-limiting example, with reference to the accompanying drawings in which: 
           [0023]      FIG. 1  is a three dimensional view from the front and from above, of a neck brace in accordance with the present invention; 
           [0024]      FIG. 2  is a side view of the neck brace of  FIG. 1 ; 
           [0025]      FIG. 3  is a three dimensional view of the neck brace of  FIG. 1 , taken from the front at an oblique angle; and 
           [0026]      FIGS. 4A to 4C  are sectional views through an impact brake element of the neck brace of  FIG. 1 , in three different operational conditions. 
       
    
    
     DETAILED DESCRIPTION  
       [0027]    Referring to  FIGS. 1 to 3 , a neck brace in accordance with the present invention is generally indicated by reference numeral  10 . 
         [0028]    The neck brace  10  includes a front section  12  and a rear section  14  which can be secured together at lateral hinge connectors  16  to form a ring that can extend around the neck of a wearer. The front section  12  is U-shaped in plan view and includes a top flange  20  defining part of a generally upwardly facing impact surface  30  that can receive impact loads from the bottom of a full face helmet worn by the wearer, a bottom flange  22  defining a cushioned chest bearing surface  44  that is configured to bear on the wearer&#39;s chest, and a structure in the form of a wall  24  that extends between the top and bottom flanges to transfer the impact loads from the helmet to the wearer&#39;s body. 
         [0029]    The rear section  14  is also U-shaped in plan view and includes a top flange  52  that is generally a continuation of the top flange  20  of the front section, with an upwardly facing impact surface  30 , and bottom flange  54  that is generally a continuation of the bottom flange  22  and that defines padded shoulder bearing surfaces  88  where it is configured to bear on the shoulders of the wearer. A structure in the form of a wall  66  extends between the top flange  52  and the bottom flange  54 . The rear section further includes two bars  68  that each extends from the rear of the bottom flange  54  along the upper back of the wearer with a padded back bearing surface  72  for bearing on the back of the wearer. 
         [0030]    The purpose of the top flanges  20  and  52  is to limit movement of the wearer&#39;s helmet during impact, e.g. during high speed motor sport accidents, by contacting the underside of the helmet with the impact surface  30  and transferring the impact load to the wearer&#39;s body via the chest, shoulder and back bearing surfaces  44 , 88 , 72  to reduce the risk of injury to the neck and upper spine of the wearer. 
         [0031]    Embodiments of the invention may utilize two bars  68  as shown or any other number of bars as one skilled in the art will recognize as any number of bars  68  including one or more displaced at any point along bottom flange  54  may be utilized in keeping with the spirit of the invention. 
         [0032]    Referring further to  FIGS. 1 to 3 , in the present invention, a rear part of the top flange  52  is pivotally connected to the remainder of the rear section  14  at pivotal joints  90 , so that it forms a rear displaceable part  92  that can pivot downwards towards the upper back of the wearer, i.e. towards the shoulder and/or back bearing surfaces  88 , 72 . Two impact brake elements  94  extend between the displaceable part  92  and each of the bars  68  to permit some pivotal movement in the joints  90 , but to inhibit undesirable pivotal movement, as described in more detail below. 
         [0033]    Similarly, a front part of the top flange  20  is pivotally connected to the remainder of the front section  12  at pivotal joints  96 , so that it forms a front displaceable part  98  that can pivot downwards towards the chest of the wearer, i.e. towards the chest bearing surface  44 . In addition, the pivotal joints  96  are configured to allow the rear ends of the displaceable part  98  to slide rearwards relative to the remainder of the front section  12  to allow the displaceable part to slide rearwards and/or pivot downwards. Two impact brake elements  100  extend between the displaceable part  98  and lateral locations on the bottom flange  22  to permit some pivotal and/or sliding movement in the joints  96 , but to inhibit undesirable pivotal and/or sliding movement, as described in more detail below. 
         [0034]    Referring to  FIGS. 4A to 4C , each of the impact brake elements  94 , 100  includes a first component in the form of an outer cylindrical sleeve  102  which defines a first, cylindrical brake surface  104  on the inside of the sleeve and a second component in the form of an elongate probe  106 , most of which is receivable inside the sleeve and which is longitudinally (i.e. axially) displaceable relative to the sleeve. The probe  106  has an elongate protuberance  108  at its upper end that protrudes outside the sleeve  102  by a degree that varies depending on the position of the probe inside the sleeve. The probe  106  defines an annular recess  110  on its circumference, with a second, tapered (i.e. frusto-conical) brake surface  112  defined on the inner circumference of the annular recess. 
         [0035]    The inner circumference of the annular recess (i.e. the tapered brake surface  112 ) is tapered at a very small angle with the result that the recess is not strictly “annular” in shape, but for the purposes of this description, the term “annular” is to be interpreted to include an annulus with a slightly tapered inner wall. 
         [0036]    A number of lock elements in the form of balls  114  are held captive inside the annular recess  110  by the wall of the sleeve  102 , i.e. between the cylindrical and tapered brake surfaces  104 , 112 . The brake element  94 , 100  is shaped and dimensioned such that the balls  14  fit inside the recess  110  with a slight clearance at the wider, lower end of the recess, such that the balls fit inside the recess with an interference fit higher in the recess. 
         [0037]    The impact brake element  94 , 100  is shown in  FIG. 4A  in a fully extended condition, with the protuberance  108  extending far outside the top of the sleeve  102 . A compression coil spring (not shown) is provided inside the sleeve  102 , below the probe  106 , to urge the probe upwardly towards its fully extended position. The lower end of the sleeve  102  is attached to the bottom flange  22  or one of the bars  68 , as the case may be, and the top end of the protuberance  108  can be attached to the relevant displaceable part  92 , 98  or can simply be positioned so that the underside of the displaceable part can press longitudinally against the end of the protuberance. 
         [0038]    Each of the impact brake elements  94 , 100  is normally in this extended condition and is held in this condition by its coil spring, but as the relevant displaceable part  92 , 98  is displaced relative to the remainder of the brace  10 , it presses the probe  106  towards the sleeve  102 , to slide further inside the sleeve against the bias of the spring. 
         [0039]    Referring to  FIG. 4B , if the probe  106  is caused to slide longitudinally downwardly into the sleeve at a relative low rate, the balls  114  are held at the lower end of the recess  110  by gravity and there is thus a clearance between the balls and the respective braking surfaces  104 , 112 , so that the sliding movement can continue without interference. 
         [0040]    However, referring to  FIG. 4C , if the probe  106  is caused to slide longitudinally downwardly into the sleeve  102  at a relative high rate, e.g. under an impact load, the inertia of the balls  114  cause them not to follow the rapid downward movement of the probe at the same rate, with the result that the balls slide upwardly relative to the recess  110  (because the probe and balls are sliding downwardly at different rates). At the higher position of the balls  114  in the recess  110 , the circumference of the tapered brake surface  112  is wider and the balls are urged outwardly by the tapered brake surface to become locked between the tapered and cylindrical brake surfaces  112 , 104  in a taper lock. 
         [0041]    The dimensions and particularly the tolerances and clearances of the balls  114  and brake surfaces  104 , 112  can be dimensioned to allow downward movement of the probe  106  relative to the sleeve  102  without interference if the rate of relative movement between the probe and the sleeve is below a predetermined rate and to activate the taper lock as described herein above, when the rate of relative movement of the probe into the sleeve exceeds the predetermined rate. 
         [0042]    It is to be understood that in the illustrated example of the present invention, the balls  114  are biased downwardly towards the wider end of the annular recess  110  by gravity. It is possible to enhance this bias or to replace it by using another biasing element such as a flexible element in the annular recess  110  that presses against the balls  114 . However, the simplicity of the illustrated configuration is shown for ease of understanding. Any other method of biasing balls  114  in the freely moving position is in keeping with the spirit of the invention. 
         [0043]    Referring to all the drawings, in use, when a wearer needs to tilt his head far backwards, e.g. when a motorcyclist is tucking into an aerodynamic position on the motorcycle and needs to get his torso as low as possible on the motorcycle, the head can be tilted backwards at a moderate (safe) rate so that the bottom edge of the motorcyclist&#39;s helmet presses the rear displaceable part  92  to pivot downwardly at a rate lower than a predetermined rate, while pressing the probes of the rear impact brake elements  94  into their respective sleeves without interference, as described above with reference to  FIG. 4B . If the rider tilts his head forward again, the impact brake elements  94  are extended by their coil springs and the rear displaceable part  92  pivots upwards. 
         [0044]    However, in the event that the rider&#39;s head is tilted backwards rapidly, e.g. during a rear impact collision, whether the impact brake elements  94  are fully extended or only partly extended, the downward impact of the bottom of the helmet on the rear displaceable part  92  will cause the rapid downward movement of the displaceable part and of the probes  106 , at a rate that is higher than the predetermined rate, and the downward movement of the probes relative to the sleeves  102  will be stopped by the taper lock as described above, with reference to  FIG. 4C . The result is that the impact load from the helmet is transferred from the displaceable part  92  along a load path via the locked rear impact brake elements  94  to the bars  68  and thus to the rider&#39;s body, to inhibit excessive head movement and to reduce the risk of injury to the rider&#39;s neck and upper spine. 
         [0045]    The same applies to the front displaceable part  98  that can be pivoted downwardly and slid rearwards at rates lower than a predetermined rate by a pressing the bottom edge of the helmet against the front displaceable part. In the event of an impact, e.g. a front impact collision that tends to cause the rider&#39;s head to rotate forward, the front displaceable part  98  will be pressed towards the wearer&#39;s chest at a rate exceeding the predetermined rate and the front impact brake elements  100  will be locked by their taper lock and will transfer the impact load along a load path from the helmet and displaceable part  98  to the chest bearing surface  44  and to the chest of the rider, to inhibit excessive head movement and to reduce the risk of injury to the rider&#39;s neck and upper spine. 
         [0046]    In addition to the advantages of the neck brace  10  mentioned above, the provision of two bars  68  spaced from the centre of the wearer&#39;s back, allows the brace to be worn comfortably with clothing such as motorcycling apparel that includes an aerodynamic protuberance or “hump” on the wearer&#39;s back, for preventing a vacuum behind the wearer&#39;s helmet at high speed. Further, the front bottom flange  22  defines a recess  116  which allows the wearer easy access to zippers or the like, that is often positioned centrally on the front of garments such as motorcycling apparel and/or to prevent discomfort by pressing on such zippers or the like.