Abstract:
A buoyancy compensator jacket includes a cushion pad lying inside a backplate of the jacket and the cushion pad is water-impervious on its surface and formed in a plurality of regions with dome-shaped swellings being convex toward the back of a wearer. The jacket including such cushion pad can prevent water permeation into the pad from occurring and a weight of the pad from increasing due to the water permeation during diving.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a buoyancy compensator jacket for diver. 
     Japanese Patent Application Publication No. 1993-112291A describes a buoyancy compensator jacket, which is provided on its back with holder means serving to fix an air tank thereto. This holder means comprise a frame member equivalent to a backplate and a sheet member made of woven fabric adapted to be would around the air tank and to fix this to the frame member. The frame member is covered with a cushion pad from the inner side of a bladder jacket in order to protect the wearer&#39;s back from uncomfortable irritation exerted by the frame member fixing the air tank to the jacket&#39;s back. 
     The cushion pad used in the known buoyancy compensator jacket is usually made of foamed material such as foamed urethane, particularly open cell material. The cushion pad is preferable so far as its elasticity is concerned. However, a considerable amount of water permeates the cells and, after diving, a weight of the bladder jacket correspondingly increases, making it difficult to walk. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide a buoyancy compensator jacket that is designed so that an initial weight of the cushion pad may be maintained even after diving. 
     According to this invention, there is provided a buoyancy compensator jacket for diving comprising a bladder jacket into which the air for buoyancy compensation can be introduced, a backplate mounted on a rear side of the bladder jacket provided with means for securing an air tank thereto, a cushion pad mounted on any one of the bladder jacket and the backplate so as to lie between the back of a wearer and the backplate. 
     The cushion pad is made of flexible elastic material which is water-impervious on a surface thereof and formed on a plurality of regions thereof with dome-shaped swellings which are convex toward the back of the wearer. 
     In the buoyancy compensator jacket according to this invention, the cushion pad lying inside the backplate and destined to be pressed against the diver&#39;s back is made of the elastic member of closed cell foam type or substantially non-cellular type which is water-impervious at least on its external surface. Accordingly, there is no anxiety that water permeation into the cushion pad might occur as the wearer dives and a weight of the cushion pad might increase after diving as the conventional cushion pad has often experienced. 
     The unique arrangement according to this invention such that bosses formed, for example, on the cushion pad are engaged with respective through-holes formed in the backplate as the bosses are elastically deformed advantageously facilitates the cushion pad and the backplate to be assembled together. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of a buoyancy compensator jacket according to this invention; 
     FIG. 2 is a perspective view of the buoyancy compensator jacket as viewed from its rear side; 
     FIG. 3 is a fragmentary exploded perspective view of the buoyancy compensator jacket; 
     FIG. 4 is a sectional view taken along line IV—IV in FIG. 3; 
     FIG. 5 is a sectional view taken along line V—V in FIG. 1; and 
     FIG. 6 is a fragmentary sectional view of a cushion pad. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Details of a buoyancy compensator jacket for diving according to this invention will be more fully understood from the description given hereunder with reference to the accompanying drawings. 
     FIGS. 1 and 2 are front and rear views of a buoyancy compensator jacket  1 , respectively, in which an air tank  5  is cylindrical and mounted on the jacket  1  as indicated by chain lines. 
     The buoyancy compensator jacket  1  includes a bladder jacket  3  into which the buoyancy compensating air can be introduced, an air tank strap  2  and a cushion pad  4 . A diver can wear the jacket  3  with a shoulder strap  6  as well as a waist belt  7  having been length-adjusted. The air tank  5  is provided on its top with a first stage  8  from which a regulator hose  9  extends to a second stage  11  from which, in turn, an inflation hose  12  extends to a rear side of the jacket  3 . A mouthpiece  13  is mounted on the second stage  11 . The air tank strap  2  extends along the outer side, then along the inner side and again along the inner side of the rear body of the jacket  3  and it longitudinal opposite ends are connected by means of a buckle  14  in a length-adjustable manner. The buckle  14  may be fastened on the air tank strap  2  to fix the air tank  5  to the jacket  3 . 
     FIG. 3 is a fragmentary exploded perspective view of the buoyancy compensator jacket  1  in which the strap  2  is not illustrated. As shown, a backplate or harness  22  and the cushion pad  4  extend inside a fabric layer  21  (i.e., above the fabric layer  21  as viewed in FIG. 3) and a pair of rod members  23  extend outside the fabric layer  21  (i.e., below the fabric layer  21  as viewed in FIG.  3 ). The backplate  22  and the rod members  23  are assembled together by means of four sets of bolts  26  and nuts  27  with the fabric layer  21  therebetween and secured to the fabric layer  21 , i.e., the jacket  3  (See FIG. 2 also). Upon achievement of securing the backplate  22  and the rod members  23  to the jacket  3 , the bolts  26  extend through respective through-holes  31 ,  32 ,  33  formed in the backplate  22 , the rod members  23  and the fabric layer  21 . The backplate  22  is formed in its middle region with four through-holes  34  and in its lower end (i.e., the vicinity of its left end as viewed in FIG.  3 ). The cushion pad  4  is formed on its lower surface with four cylindrical bosses  37  projecting downward and one L-shaped boss  38 . The cushion pad  4  may be placed upon the backplate  22  which has already been secured to the jacket  3  to engage the cylindrical bosses  37  with the respective through-holes  34 , on one hand, and to engage the L-shaped boss  38  with the through-hole  36 . In this manner, the pad  4  is assembled with the plate  22 , so the pad  4 , the plate  22 , the fabric layer  21  and the rod members  23  are integrally placed upon one another in the vertical direction. 
     In the assembly of the pad  4 , the plate  22  and the fabric layer  21  placed upon one another, first rectangular slots  41  of the pad  4 , second rectangular slots  42  of the plate  22  and third rectangular slots  43  of the fabric layer  21  are aligned one with another. In the assembly of the plate  22 , the fabric layer  21  and the rod members  23  placed upon one another, fourth rectangular slots  44  of the plate  22 , fifth rectangular slots  45  of the fabric layer  21  and sixth rectangular slots  46  of the rod members  23  are aligned with one another. The air tank strap  2  is inserted successively into these rectangular slots until the state shown in FIGS. 1 and 2 is established. 
     The cushion pad  4  is symmetrical about a center line C—C bisecting a width of the jacket  3  on its rear body and comprises an upper portion  51  extending along the center line C—C vertically of the jacket  3  to cover the plate  22  and a lower portion  52  extending circumferentially of the jacket  3 , i.e., orthogonally to the center line C—C. The upper portion  51  is formed with a first pair of dome-shaped swellings  53  projecting toward a jacket wearer&#39;s back on both sides of the center line C—C, respectively. Similarly, the lower portion  52  is formed on each side of the center line C—C with three second swellings  54 , specifically,  54 A,  54 B,  54 C arranged circumferentially of the wearer&#39;s torso. These second swellings  54 A,  54 B,  54 C have their respective dimensions as measured in the direction of the center line C—C progressively reducing as they go away from the center line C—C. 
     FIG. 4 is a sectional view taken along line IV—IV in FIG. 3, in which chain lines indicate an outline defined by the back of the diver wearing the buoyancy compensator jacket  1  and the cushion pad  4  curved in contact with the outline  56 . Except the bosses  37 ,  38  and ribs R (See FIGS.  1  and  3 ), the cushion pad  4  has a substantially uniform thickness and partially depressed at the second swellings  54  so as to be convex toward the outline  56  of the wearer&#39;s back in the form of domes. Similarly to the second swellings  54 , the first pair of swellings  53  are dome-shaped. Such cushion pad  4  is made of flexible elastic material such as plastic elastomer so that both the first swellings  53  and the second swellings  54  may be elastically deformed as these swellings  53 ,  54  are pressed against the diver&#39;s back to provide a desired cushioning effect. In this way, it is not apprehended that the back plate  22  might be uncomfortably pressed against the diver&#39;s back. To improve the cushioning effect, the cushion pad  4  according to this embodiment adopts an arrangement such that the second swellings  54 A,  54 B,  54 C have their respective dimensions as measured in the direction of the center line C—C progressively reduced as they go away from the center line C—C (See FIG.  3 ). Also to improve the cushioning effect, the second swellings  54  are formed so that their heights H from their peripheries progressively increased as they go away from the center line C—C. 
     For such cushion pad  4 , it is important that at least its outer surface should be water-impervious so that water permeation into the pad  4  may not occur and, to meet such requirement, substantially non-porous or closed cell foamed plastic elastomer, rubber or the like is used as the flexible elastic material to form such cushion pad  4 . 
     FIG. 5 is a sectional view taken along line V—V in FIG.  1 . In the cushion pad  4 , the cylindrical bosses  37  are engaged with the respective through-holes  34  of the backplate  22  as the cylindrical bosses  37  are elastically deformed and simultaneously the diameter-enlarged portions  37 A of the respective bosses  37  are pressed against the outer surface  22   a  of the backplate  22  around the respective through-holes  34  so that the bosses  37  may be reliably prevented from falling off from the respective through-holes  34 . Similarly, the L-shaped boss  38  is engaged with the through-hole  36  of the backplate  22  as this L-shaped boss  38  is elastically deformed and the leg portion  38 A of this L-shape defining a distal end of this boss  38  is pressed against the outer surface  22 A of the backplate  22 . 
     FIG. 6 is a fragmentary sectional view of the cushion pad  4  having a construction differing from that of the cushion pad  4  shown in FIG.  5 . The pad  4  according to this embodiment also is made of the flexible elastic member but different from that shown in FIG. 5 in that, as viewed in its section, the pad  4  comprises skin layers  61 ,  62  defining inner and outer surfaces of the pad  4  and a core layer  63  disposed between these two skin layer  61 ,  62 . The skin layers  61 ,  62  are substantially non-cellular and prevent water permeation into the core layer  63  which has, in turn, a plurality of closed cells contributing to the light weight cushion pad  4 . 
     It is possible without departing from the scope of this invention to secure the cushion pad  4  to the backplate  22  by forming the swellings on the backplate  22 , instead of on the cushion pad  4  as in the illustrated embodiment so that these swellings may be engaged with respective depressions form in the cushion pad  4  as the cushion pad  4  is elastically deformed.