Patent Publication Number: US-11375766-B2

Title: Adjustable helmet for a hockey or lacrosse player

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 15/139,536, filed Apr. 27, 2016, now pending, which is a continuation of U.S. patent application Ser. No. 13/548,622, filed Jul. 13, 2012, now U.S. Pat. No. 9,345,282, which claims the benefit of U.S. Provisional Patent Application No. 61/512,076, filed Jul. 27, 2011, and of U.S. Provisional Patent Application No. 61/587,040, filed Jan. 16, 2012, all of which are hereby incorporated by reference herein in their entireties. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an adjustable helmet for a hockey or lacrosse player. 
     BACKGROUND OF THE INVENTION 
     Adjustable helmets made up of a front shell, a rear shell and fastening means are well known in the field of sports equipment, and especially in the field of hockey helmets. 
     U.S. Pat. No. 6,966,075 relates to an adjustable hockey helmet comprising: a back shell having a smooth interference-free sliding surface and two sides, wherein each side comprises two elongated slots and a series of anchoring holes, a front shell having a smooth interference-free sliding surface and two sides, wherein each side comprises a wing element adapted to overlap the interference-free sliding surface of the back shell, two slots and two anchoring holes. The front shell and the back shell are movably connected to each other by a peg inserted within the two elongated slots of the back shell and the two slots of the front shell. The helmet also comprises left and right manually operated locking devices. More particularly, the front shell has a left locking device mounted to the left wing and a right locking device mounted to the right wing. Each of the left and right locking devices has two teeth and is movable between a locked position and a released position. In the locked position, two teeth engage the two anchoring holes of the front shell and two holes of the series of holes of the back shell. In the released position, two teeth do not engage the series of anchoring holes of the back shell for allowing the front shell and the back shell to move in relation to each other. 
     Against this background, there is a need in the industry for an adjustable helmet where the player can move a single actuator between a first locked position, wherein the first and second shells define a first hollow space for receiving the player&#39;s head, a released position, wherein the first and second shells are moveable relative to one another, and a second locked position, wherein the first and second shells define a second hollow space for receiving the player&#39;s head, the second hollow space being different than the first hollow space. The single actuator is mounted on the top portion of the helmet such that use of two actuators on each side of the helmet is eliminated. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, there is provided an adjustable helmet for receiving a head of a hockey or lacrosse player, the head having a crown region, left and right side regions, a top region, a back region and an occipital region, the helmet extending along a longitudinal axis and comprising: (a) a first shell having a first top portion for facing at least partially the top region of the player&#39;s head, a front portion for facing at least partially the crown region of the player&#39;s head, and left and right side portions extending rearwardly from the front portion for facing at least partially the left and right side regions of the player&#39;s head; (b) a second shell having a second top portion for facing at least partially the top region of the player&#39;s head, a rear portion for facing at least partially the back and occipital regions of the player&#39;s head, and left and right side portions extending forwardly from the rear portion for facing at least partially the left and right side regions of the player&#39;s head; and (c) a single actuator comprising at least one tooth extending substantially transversely relative to the longitudinal axis, the single actuator being mounted to one of the first and second top portions; wherein one of the first and second top portions comprises at least one aperture extending substantially transversely relative to the longitudinal axis and wherein the other one of the first and second top portions comprises a plurality of apertures extending substantially transversely relative to the longitudinal axis; wherein, in use, the single actuator is moveable by the player between: a first locked position, wherein the at least one tooth extends in the at least one aperture and in a first aperture of the plurality of apertures and wherein the first and second shells define a first hollow space for receiving the player&#39;s head; a released position, wherein the at least one tooth no longer extends in the at least one aperture and the plurality of apertures such that one of the first and second shells is moveable relative to the other of the first and second shells; and a second locked position, wherein the at least one tooth extends in the at least one aperture and in a second aperture of the plurality of apertures and wherein the first and second shells define a second hollow space for receiving the player&#39;s head, the second hollow space being different than the first hollow space. 
     This and other aspects and features of the present invention will now become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A detailed description of the embodiments of the present invention is provided herein below, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a head of a player; 
         FIG. 2  is a right side elevational view of the head of the player of  FIG. 1 ; 
         FIG. 3  is a front perspective exploded view of a helmet constructed in accordance with an embodiment of the invention; 
         FIG. 4  is a rear perspective exploded view of the helmet of  FIG. 3 ; 
         FIG. 5A  shows a top view of the first shell of the helmet of  FIG. 3 ; 
         FIG. 5B  shows a top view of the second shell of the helmet of  FIG. 3 ; 
         FIG. 6  is a rear side perspective view of the helmet of  FIG. 3 ; 
         FIG. 7  is a rear side perspective view of the helmet of  FIG. 3 , with the single actuator shown in a released position; 
         FIG. 8  is an enlarged rear elevational view of the single actuator shown in a released position; 
         FIG. 9A  is a side view of the helmet of  FIG. 3 , with the single actuator in a first locked position, wherein the first and second shells define a first hollow space for receiving the player&#39;s head; 
         FIG. 9B  is a front view of the helmet corresponding to the position shown in  FIG. 9A ; 
         FIG. 10A  is a side view of the helmet of  FIG. 3 , with the single actuator shown in a released position and showing movement of the back shell relative to the first shell; 
         FIG. 10B  is a front view of the helmet corresponding to the position shown in  FIG. 10A ; 
         FIG. 11A  is a side view of the helmet of  FIG. 3 , with the single actuator in the released position; 
         FIG. 11B  is a front view of the helmet corresponding to the position shown in  FIG. 11A ; 
         FIG. 12A  is a side view of the helmet of  FIG. 3 , with the single actuator in a second locked position, wherein the first and second shells define a second hollow space for receiving the player&#39;s head; 
         FIG. 12B  is a front view of the helmet corresponding to the position shown in  FIG. 12A ; 
         FIG. 13A  is an enlarged cross-sectional view of the helmet of  FIG. 9B  taken along line  13 A- 13 A; 
         FIG. 13B  is an enlarged cross-sectional view showing the single actuator in the first locked position; 
         FIG. 14  is an enlarged cross-sectional view of the helmet of  FIG. 10B  taken along line  14 - 14 ; 
         FIG. 15  is an enlarged cross-sectional view of the helmet of  FIG. 11B  taken along line  15 - 15 ; 
         FIG. 16A  is an enlarged cross-sectional view of the helmet of  FIG. 12B  taken along line  16 A- 16 A; 
         FIG. 16B  is an enlarged cross-sectional view showing the single actuator in the released position in broken lines and the single actuator in the second locked position in full lines; 
         FIG. 17  is an enlarged bottom perspective view of the actuator; 
         FIG. 18  is a cross-sectional view of the actuator of  FIG. 17  taken along line  18 - 18 ; 
         FIG. 19  is a cross-sectional view of the actuator of  FIG. 17  taken along line  19 - 19 ; and 
         FIG. 20  is an enlarged top perspective view of a base member. 
     
    
    
     In the drawings, embodiments of the invention are illustrated by way of examples. It is to be expressly understood that the description and drawings are only for the purpose of illustration and are an aid for understanding. They are not intended to be a definition of the limits of the invention. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION 
     To facilitate the description, any reference numeral designating an element in one figure will designate the same element if used in any other figures. In describing the embodiments, specific terminology is resorted to for the sake of clarity but the invention is not intended to be limited to the specific terms so selected, and it is understood that each specific term comprises all equivalents. 
     Unless otherwise indicated, the drawings are intended to be read together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms “horizontal”, “vertical”, “left”, “right”, “up”, “down” and the like, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, “radially”, etc.), simply refer to the orientation of the illustrated structure. Similarly, the terms “inwardly,” “outwardly” and “radially” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate. 
       FIGS. 1 and 2  illustrate a head of a hockey or lacrosse player. The head comprises a crown region CR, left and right side regions LS, RS, a back region BR and an occipital region OR. The crown region CR has a front part that substantially corresponds to the forehead and a top part that substantially corresponds to the front top part of the head. In fact, the crown region CR generally corresponds to the frontal bone region of the head. The left and right side regions LS, RS are approximately located above the ears of the player. The occipital region OR substantially corresponds to the region around and under the external occipital protuberance of the head. 
       FIGS. 3 and 4  show an adjustable helmet  10  for receiving the head of the hockey or lacrosse player. The helmet  10  extends along a longitudinal axis A-A and comprises a first shell  12  and a second shell  14  interconnected together. As shown, the first shell  12  may be a front shell and the second shell  14  may be a rear shell. The first shell  12  and second shell  14  may be made of a relatively rigid material, such as polyethylene, NYLON, polycarbonate materials, thermoplastics, or thermosetting resins or any other suitable material. The first and second shells  12 ,  14  include a plurality of ventilation apertures that provide the added comfort of allowing air to circulate around the head of the player. 
     The first shell  12  has a first top portion  12   TP  for facing at least partially the top region of the player&#39;s head, a front portion for facing at least partially the crown region of the player&#39;s head, and left and right side portions extending rearwardly from the front portion for facing at least partially the left and right side regions of the player&#39;s head. 
     The second shell  14  has a second top portion  14   TP  for facing at least partially the top region of the player&#39;s head, a rear portion for facing at least partially the back and occipital regions of the player&#39;s head, and left and right side portions extending forwardly from the rear portion for facing at least partially the left and right side regions of the player&#39;s head. As shown the first top portion  12   TP  may be a front top portion and the second top portion  14   TP  may be a rear top portion. 
     The first shell  12  overlays left and right front inner pads  15 ,  16  while the second shell  14  overlays left and right rear inner pads  18 ,  20  and a top inner pad  22 . The left and right front inner pads  15 ,  16  face the crown region CR and face at least partially the left and right side regions LS, RS. The left and right rear inner pads  18 ,  20  face the back region BR and face at least partially the left and right side regions LS, RS. The top inner pad  22  faces the back and top regions of the head. The inner pads  16 ,  18 ,  20 ,  22  may be made of shock absorbing materials such as expanded polypropylene (EPP) or expanded polyethylene (EPE). Other materials can also be used without departing from the spirit of the invention. 
     The left and right front inner pads  15 ,  16  have a three-dimensional external configuration that matches the three-dimensional internal configurations of the first shell  12  and is mounted to the first shell  12  by any suitable means such glue, stitches, tacks, staples or rivets. Similarly, the left and right rear inner pads  18 ,  20  have three-dimensional external configurations that match the three-dimensional internal configurations of the second shell  14  and are mounted to the second shell  14  by any suitable means, such as glue, stitches, tacks, staples or rivets. 
     The helmet  10  may also comprise left and right comfort pads  24 ,  26  facing the left and right side regions and located just above the ears and left and right comfort pads  28 ,  30  facing the left and right temple regions of the head. The helmet  10  may further comprise left and right comfort pads  25 ,  27  facing the left and right side regions and located just above the ears and between the first and second shells  12 ,  14 . The comfort pads  24 ,  25 ,  26 ,  27 ,  28 ,  30  may be made of soft materials such as polyvinyl chloride (PVC). Other materials can also be used without departing from the spirit of the invention. The comfort pads  24 ,  25 ,  26 ,  27 ,  28 ,  30  may be affixed on the inner surface of the corresponding inner pads or shells by any suitable means, such as glue or an adhesive layer. 
     The helmet  10  may comprise left and right ear covers  32 ,  34  for protecting the ears of the player. 
     The helmet  10  may also comprise an occipital pad  36  facing the occipital region OR of the player&#39;s head and movable relative to the second shell  14  between different positions to adjust the fit of the helmet  10  on the player&#39;s head. 
     The occipital pad  36  may be made of any suitable padding material. For example, in some embodiments, the occipital pad  36  may comprise polymeric foam such as expanded polypropylene (EPP) foam, expanded polyethylene (EPE) foam, foam having two or more different densities (e.g., high-density polyethylene (HDPE) foam and low-density polyethylene foam), or any other suitable foam. Other materials may be used for the occipital pad  36  in other embodiments. 
     As best shown in  FIG. 4 , the occipital pad  36  is supported by a support  38  which is movable relative to the second shell  24  in order to move the occipital pad  36 . A wedge  40  (best shown in  FIG. 3 ) is located between the second shell  14  and the support  38  and connected to an actuator  42  such that, when the player operates the actuator  42 , the wedge  40  moves between different positions relative to the second shell  14  and the support  38 . The wedge  40  has a thickness that increases gradually from its top edge to its bottom edge such that downward vertical displacement of the wedge  40  between the second shell  14  and the support  38  moves the occipital pad  36  from a first position towards a second position in which it applies a greater pressure upon the occipital region OR of the player&#39;s head. Movement of the occipital pad  36  allows it to be positioned in a first position in which it is closer to the back portion of the second shell  14  and in a second position in which it is further inward of the helmet  10  and closer to the occipital region OR to apply more pressure on the occipital region OR than in its first position. 
     As best shown in  FIGS. 3 and 4 , the support  38  may have an upper portion with left and right connectors, projections or pins  38 A that are received in apertures provided in the rear inner pads  18 ,  20  (see aperture  20 A) such that the support is mounted to the rear inner pads  18 ,  20 . The upper portion of the support  38  may also comprise a member extending upwardly with a connector, projection or pin  38 B that is received in an aperture  22 A provided in the top inner pad  22  such that the top inner pad  22  is only affixed at that point to the second shell  14 . 
     The helmet  10  also comprises a single actuator  50  comprising at least one tooth extending substantially transversely relative to the longitudinal axis A-A. 
     As best seen in  FIGS. 8 and 17 , the single actuator  50  has a cam member  51  adapted to pivot about an axis B-B that extends substantially transversely relative to the longitudinal axis A-A and the single actuator  50  extends from the cam member  51  and has a handle  53  for allowing the player to move the single actuator  50  between a first locked position (shown in  FIG. 13B ), a released position (shown in  FIG. 14 ) and a second locked position (shown in full lines in  FIG. 16B ). The handle  53  may have a curved or recessed portion for allowing movement or rotation of the single actuator  50  by the player with only one finger or with only the thumb. 
     The single actuator  50  may comprise a first pair of first and second teeth  52 A 1 ,  52 A 2  being spaced apart and a second pair of first and second teeth  52 B 1 ,  52 B 2  being spaced apart. Each of the first and second teeth  52 A 1 ,  52 A 2  and first and second teeth  52 B 1 ,  52 B 2  extend substantially transversely relative to the longitudinal axis A-A (or along an axis substantially parallel to the axis B-B). 
     The single actuator  50  is mounted to one of the first and second top portions  12   TP ,  14   TP . For example, the second top portion  14   TP  may comprise first and second posts  56 A,  56 B and the single actuator  50  may be pivotally mounted relative to the first and second posts  56 A,  56 B. The first and second posts  56 A,  56 B may be integrally formed with the second top portion  14   TP . Alternatively, as best shown in  FIGS. 3, 4 and 20 , the first and second posts  56 A,  56 B may be part of a base member  56  and the first and second posts  56 A,  56 B may extend in apertures  14 A,  14 B provided in the second top portion  14   TP  (see  FIG. 5B ). The base member  56  may also have a base  56 C with first and second apertures  56 D 1 ,  56 D 2  (see  FIG. 20 ). 
     Reverting to  FIG. 8 , the single actuator  50  may have first and second walls  58 A,  58 B abutting against the first and second posts  56 A,  56 B respectively and a wire  60  may slide through holes provided in the first and second walls  58 A,  58 B and first and second posts  56 A,  56 B. In one embodiment, the wire  60  may be a wire clip in the shape of a dovetail with both of its ends exerting an external force when it is inserted in the holes. This ensures that the wire  60  will not fall out accidentally, since it would need to be manually compressed in order to be removed. 
     One of the first and second top portions  12   TP ,  14   TP  comprises at least one aperture extending substantially transversely relative to the longitudinal axis A-A and the other one of the first and second top portions  12   TP ,  14   TP  comprises a plurality of apertures extending substantially transversely relative to the longitudinal axis A-A. 
     Referring to  FIGS. 5A, 5B, 13B and 16B , the second top portion  14   TP  has a pair of first and second apertures  62   1 ,  62   2  being spaced apart. It is understood that the first and second apertures  62   1 ,  62   2  may be replaced by one aperture or opening that is large enough for receiving the first pair of first and second teeth  52 A 1 ,  52 A 2  and second pair of first and second teeth  52 B 1 ,  52 B 2 . The first top portion  12   TP  has a plurality of pairs of first and second apertures  64 A 1 ,  64 A 2 ;  648   1 ,  64 B 2 ;  64 C′,  64 C 2 ;  64 D 1 ,  64 D 2 ;  64 E 1 ,  64 E 2 ;  64 F 1 ,  64 F 2 ;  64 G 1 ,  64 G 2 ;  64 H 1 ,  64 H 2 , More specifically, in one embodiment, the first top portion  12   TP  may have a first and second series of eight apertures extending substantially transversely relative to the longitudinal axis A-A, the first and second series of apertures being spaced apart. 
     Referring to  FIG. 13B  showing the single actuator  50  in the first locked position, the first tooth  52 A′ and the first tooth  52 B 1  extend in the first aperture  62   1 . The first tooth  52 A 1  and the first tooth  52 B 1  also extend in first apertures of the plurality of first apertures  64 A 1 ,  64 B 1 ,  64 C 1 ,  64 D 1 ,  64 E 1 ,  64 F 1 ,  64 G 1 ,  64 H 1  (more specifically, the first tooth  52 A 1  and the first tooth  52 B 1  extend in apertures  64 D 1 ,  64 E 1 ). It is understood that the second tooth  52 A 2  and the second tooth  52 B 2  also extend in the second aperture  62   2  and the second tooth  52 A 2  and the second tooth  52 B 2  also extend in first apertures of the plurality of second apertures  64 A 2 ,  64 B 2 ,  64 C 2 ,  64 D 2 ,  64 E 2 ,  64 F 2 ,  64 G 2 ,  64 H 2  (more specifically, the second tooth  52 A 2  and the second tooth  52 B 2  extend in apertures  64 D 2 ,  64 E 2 ). It is also understood that the first pair of first and second teeth  52 A 1 ,  52 A 2  and second pair of first and second teeth  52 B 1 ,  52 B 2  may extend in the first and second apertures  56 D 1 ,  56 D 2  of the base member  56 . It is understood that the first and second apertures  56 D 1 ,  56 D 2  may be replaced by one aperture or opening that is large enough for receiving the first pair of first and second teeth  52 A 1 ,  52 A 2  and second pair of first and second teeth  52 B 1 ,  52 B 2 . 
     In the first locked position, the first and second shells  12 ,  14  define a first hollow space HS 1  for receiving the player&#39;s head. 
     The single actuator  50  is movable to a released position, wherein the at least one tooth no longer extends in the at least one aperture and the plurality of apertures such that one of the first and second shells  12 ,  14  is moveable relative to the other of the first and second shells  12 ,  14 . 
     As best shown in  FIG. 14 , the first tooth  52 A 1  and the first tooth  52 B 1  no longer extend in the first aperture  62   1  and the first tooth  52 A 1  and the first tooth  52 B 1  no longer extend in the first apertures of the plurality of first apertures  64 A 1 ,  64 B 1 ,  64 C 1 ,  64 D 1 ,  64 E 1 ,  64 F 1 ,  64 G 1 ,  64 H 1  (which were apertures  64 D 1 ,  64 E 1 ) such that one of the first and second shells  12 ,  14  is moveable relative to the other of the first and second shells  12 ,  14 . It is understood that the second tooth  52 A 2  and the second tooth  52 B 2  also no longer extend in the second aperture  62   2  and the second tooth  52 A 2  and the second tooth  52 B 2  also no longer extend in the first apertures of the plurality of second apertures  64 A 2 ,  64 B 2 ,  64 C 2 ,  64 D 2 ,  64 E 2 ,  64 F 2 ,  64 G 2 ,  64 H 2  (which were apertures  64 D 2 ,  64 E 2 ). 
     In use, a player who puts on the helmet  10  and realizes that it is too large or too small, does not need to remove the helmet  10 . The player must simply reach up and grasp the single actuator  50  (the handle  53 ) and rotate the actuator  50 . As best shown in  FIGS. 6 and 7 , the single actuator  50  is mounted to the second top portion  14   TP  and is pivotable about an axis that extends substantially transversely relative to the longitudinal axis A-A (or along an axis substantially parallel to the axis 
     B-B shown in  FIG. 8 ) and the single actuator  50  is also located at a central location where it overlies the longitudinal axis A-A such that the player can easily reach up the single actuator  50  (the handle  53 ) in order to rotate the single actuator  50  with the thumb or with only one finger and bring the single actuator  50  in the released position shown in  FIGS. 7 and 14 . 
     Because the helmet  10  has a single actuator, namely the actuator  50 , the player can actuate, move or rotate the single actuator  50  with only one hand as opposed to using both hands as required by prior helmets wherein left and right locking devices are located on both sides of the helmet. By providing the single actuator  50  on one of the first and second top portions  12   TP ,  14   TP , this allows to reduce the manufacturing cost and the number of components of the helmet. Moreover, because actuators on the left and right sides of the helmet are eliminated, those sides may be designed as being thinner such that the helmet may be generally less bulky. 
     Once the single actuator  50  is in the released position, the player can expand or contract the size of the helmet  10  by pushing or pulling the first and second shells  12 ,  14  in relation to each other. As shown in  FIG. 14 , the second shell  14  is pushed rearwardly in order to increase the size of the hollow cavity defined by the first and second shells  12 ,  14 . 
     As indicated previously, the top inner pad  22  is only affixed to the second shell  14  at only one point (connector  38 B best seen in  FIG. 3 ). The upper surface of the top inner pad  22  may also comprise a recess  22 B for at least partially receiving the base  56 C of the base member  56  and the top inner pad  22 , base member  56  and actuator  50  thus move with the second shell  14  when the first and second shells  12 ,  14  move relative to each other. Moreover, as best seen in  FIGS. 5A, 13B and 16B , the first top portion  12   TP  may define a band, strip or extension extending generally rearwardly along the axis A-A and being at least partially located between the second top portion  14   TP  and the base  56 C of the base member  56 . The bottom surface of the second top portion  14   TP  may also comprise a channel or a rectangular opening for at least partially receiving the first top portion extension. 
     Once the player has selected a desired helmet size, the first shell  12  and second shell  14  must be securely locked in place so that movement of the first and second shells  12 ,  14  in relation to each other is prevented. The player must then actuate (rotate) the actuator  50  such that this actuator is in a second locked position, wherein the at least one tooth extends in the at least one aperture and in a second aperture of the plurality of apertures. 
     Referring to  FIG. 16B  showing the single actuator  50  in the second locked position, the first tooth  52 A 1  and the first tooth  52 B 1  extend in the first aperture  62   1 . The first tooth  52 A 1  and the first tooth  52 B 1  also extend in second apertures of the plurality of first apertures  64 A 1 ,  64 B 1 ,  64 C 1 ,  64 D 1 ,  64 E 1 ,  64 F 1 ,  64 G 1 ,  64 H 1  (more specifically, the first tooth  52 A 1  and the first tooth  52 B 1  extend in apertures  64 G′,  64 H 1 ). It is understood that the second tooth  52 A 2  and the second tooth  52 B 2  also extend in the second aperture  62   2  and the second tooth  52 A 2  and the second tooth  52 B 2  also extend in second apertures of the plurality of second apertures  64 A 2 ,  64 B 2 ,  64 C 2 ,  64 D 2 ,  64 E 2 ,  64 F 2 ,  64 G 2 ,  64 H 2  (more specifically, the second tooth  52 A 2  and the second tooth  52 B 2  extend in apertures  64 G 2 ,  64 H 2 ). 
     In the second locked position, the first and second shells  12 ,  14  define a second hollow space HS 2  for receiving the player&#39;s head. As best shown in  FIGS. 13A and 16A , the second hollow space HS 2  is different (larger) that the first hollow space HS 1 . 
     It is understood that either of the first pair of teeth  52 A 1 ,  52 A 2  or the second pair of teeth  52 B 1 ,  52 B 2  may be omitted such that the single actuator  50  has only one pair of teeth. It is also understood that the single actuator  50  may only have one tooth extending along the width of the actuator  50  instead of a pair of first and second teeth being spaced apart or instead of the first pair of first and second teeth  52 A 1 ,  52 A 2  and the second pair of first and second teeth  52 B 1 ,  52 B 2 . Similarly, it is understood that the second top portion  14   TP  may have one single aperture instead of the pair of first and second apertures  62   1 ,  62   2  and the first top portion  12   TP  may have a plurality of single apertures instead of the plurality of pairs of first and second apertures  64 A 1 ,  64 A 2 ;  64 B 1 ,  64 B 2 ;  64 C 1 ,  64 C 2 ;  64 D 1 ,  64 D 2 ;  64 E 1 ,  64 E 2 ;  64 F 1 ,  64 F 2 ; 
       64 G 1 ,  64 G 2 ;  64 H 1 ,  64 H 2 . 
     If the single actuator  50  has only one tooth, in the first locked position, this tooth extends in the single aperture of the second top portion  14   TP  and in a first aperture of the plurality of apertures of the first top portion  12   TP , and in the second locked position, this tooth extends in the single aperture of the second top portion  14   TP  and in a second aperture of the plurality of apertures of the first top portion  12   TP . 
     It is understood that the width and thickness of the tooth (e.g. first and second teeth  52 A 1 ,  52 A 2 ) are determined such that the tooth is tightly received in its corresponding aperture of the series of apertures (e.g. apertures  64 A 1 ,  64 B 1 ,  64 C 1 ,  64 D 1 ,  64 E 1 ,  64 F 1 ,  64 G 1 ,  64 H 1 ) in order to prevent movement of the first and second shells  12 ,  14  relative to each other. The tooth should therefore tightly register, extend or fit in its corresponding aperture of the series of apertures when the actuator is in the first or second locked position. Moreover, the width, thickness and/or length of the tooth (e.g. first and second teeth  52 A 1 ,  52 A 2 ) are determined such that the tooth can sustain a force due to an impact on the helmet. As best shown in  FIG. 19 , the tooth may have a generally rectilinear or straight portion  150  followed by a shorter arcuate or curved portion  152 . The straight portion  150  may have a length between 0.8 cm and 1.2 cm and the curved portion  152  may extend over a length between 0.1 cm to 0.4 cm. The thickness of the tooth may be between 0.1 cm and 0.3 cm. The tooth may have a width between 0.8 cm and 1.2 cm. 
     The left and right portions of the first shell  12  may have left and right sliding surfaces, each of the left and right sliding surfaces having first and second projections  72  (pegs) extending inwardly, wherein the left and right portions of the second shell  14  have left and right sliding surfaces, each of the left and right sliding surfaces having first and second slots  70  extending along an axis substantially parallel to the longitudinal axis A-A, and wherein the left and right sliding surfaces of the first shell  12  overlap at least partially the left and right sliding surface of the second shell  14 . 
     The first and second projections  72  register in the first and second slots  70  respectively such that the first and second projections  72  are moveable within the first and second slots  70  between first and second sliding positions when the first and second shells  12 ,  14  move from the first and second locked positions. The left and right sliding surfaces of the first shell  12  may at least partially overlap the left and right sliding surface of the second shell  14 . 
     The left and right sliding surfaces of the first and second shells  12 ,  14  may define smooth, interference-free sliding surfaces that are adapted to be in contact with each other when the helmet  10  is secured in a selected position. The interference-free sliding surfaces of the helmet  10  still experience minor unavoidable friction, but can be moved in relation to each other without substantial interference and in a smooth movement. 
     The slot and peg assembly allows the first shell  12  and the second shell  14  to slide backwards and forwards and guides their relative movement. The slots  70  determine the path of movement of the first shell  12  and the second shell  14  with respect to each other. As can be seen in  FIGS. 13A, 14, 15 and 16A , the slots  70  may be oriented in a slightly downward sloping direction from the rear to the front of the helmet  10 . Alternatively, the slots  70  may be positioned at any angle depending on how the first shell  12  and the second shell  14  are designed to move in relation to each other. 
     The above description of the embodiments should not be interpreted in a limiting manner since other variations, modifications and refinements are possible within the scope of the present invention. The scope of the invention is defined in the appended claims and their equivalents.