Abstract:
A scuba tank accessory unit improves the diver experience by providing a streamlined diving unit for a back mounted diving device. The diving unit has a propulsion unit having a space for mounting a battery powered electric motor, armature extending out one end of the propulsion unit and further attached to a propellor. A battery pack is contained in a housing unit located either concentrically about the electric motor or atop it such that the electric motor extends slightly therein with a depression or cavity at the bottom of the housing unit.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a battery powered propulsion unit for an underwater breathing apparatus having a tank worn on the diver&#39;s back. More specifically, the invention relates to a more perfect arrangement of the battery units within a back mounted propulsion unit. 
     BACKGROUND OF THE INVENTION 
     Underwater motion has always been a challenge to fisherman, deep sea explorers and hobbyists. The various factors unique to the ocean environment such as salinity, pressure, density and temperature and more present obstacles to be overcome when swimming under the ocean. Because of the aforementioned, scuba equipment designers must offer solutions that can meet the increased demands for performance, portability and streamlining of the propulsion unit. 
     Prior propulsion units such as that found in U.S. Pat. No. 4,467,742 awarded to Gustavo Duboy (herein incorporated by reference) have provided a novel battery system located on opposite sides of a belt such as shown in FIG. 1. In particular, the &#39;742 patent teaches a battery-powered propulsion unit for a diver&#39;s tank has an electric motor driving a propellor and mounted in a housing which is attachable to the lower end of the tank. A belt worn on the diver&#39;s waist carries first and second groups of battery holders, each made up of separable halves which are releasably attached to the belt on opposite sides of its buckle. The buckle carries a control switch for the motor which is connected by flexible cables to the motor and to the first and second groups of battery holders. 
       FIG. 1A  presents a prior art solution having a scuba tank harness mounted on a propulsion unit mounted to the back of an individual having a waist mounted battery holder unit.  FIG. 1B  illustrates a closeup of a cross section of the scuba tank harness, propulsion unit, protective shroud covering the propulsion unit and the electric motor effecting the forwards motion. 
     This prior art solution has many novelties that were good for the time it was created. However, a failing of this prior art system is that the battery packs are located on opposite sides of the user&#39;s waist; another is that the bulky non-streamlined nature of the battery holders create a reduction in fluid flow. These two realities of the prior art system combine to create a drag effect when the propulsion unit is engaged. Thus, there needs to be some solution to overcome the problems found in the prior art. 
     Accordingly, there remains a need in the art for providing a battery powered propulsion unit that does not suffer from a bulky ungainly battery holder unit. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the deficiencies of the known art and the problems that remain unsolved by providing a system. 
     In accordance with one embodiment a diver&#39;s tank apparatus comprising:
     a propulsion unit having a space therein for positioning of   an electric motor with   an armature connected thereto and   a battery pack arranged about the periphery of the electric motor.   

     In another aspect, a plurality of batteries each arranged between a pair of battery holders and arranged in series to create a predetermined voltage. 
     In another embodiment, a propulsion unit comprising:
     a propulsion unit housing   an electric motor connected to   a propellor armature threaded through an opening in the propulsion unit housing and   a battery holder unit disposed concentrically about the electric motor.   

     In another aspect, wherein the battery holder unit further comprises an annular holder device. 
     In another embodiment, a diver propulsion unit comprising:
     a motor having   a propellor and its armature attached thereto and to   a battery housing wherein the motor is disposed underneath the housing and a head of the motor extends into the housing through an opening in the housing.   

     In another aspect, a streamlined propulsion unit attached to the battery housing, the motor and the propellor armature. 
     These and other aspects, features, and advantages of the present invention will become more readily apparent from the attached drawings and the detailed description of the preferred embodiments, which follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The preferred embodiments of the invention will hereinafter be described in conjunction with the appended drawings provided to illustrate and not to limit the invention, in which: 
         FIG. 1A  presents a prior art solution having a scuba tank harness mounted on a propulsion unit mounted to the back of an individual having a waist mounted battery holder unit.  FIG. 1B  illustrates a closeup of a cross section of the scuba tank harness, propulsion unit, protective shroud covering the propulsion unit and the electric motor effecting the forwards motion. 
         FIG. 2A  presents an isometric view of a scuba tank harness or holder being disengaged from the battery propulsion propellor unit.  FIG. 2B  presents an isometric view of the rear portion of the battery propulsion propellor unit showing the propellor protruding out the rear of the unit. 
         FIG. 3A  presents a top view of the propulsion unit showing the battery unit of the present embodiment;  FIG. 3B  illustrates a section view through the propulsion unit;  FIG. 3C  is an isometric view of a propulsion unit;  FIG. 3D  illustrates the electrical connections made at the bottom inner portion of the battery holder;  FIG. 3E  illustrates the electrical connections made at the bottom portion of a sealing lid for the battery holder. 
         FIG. 4A  illustrates a top view of a  40  cell battery convention of another embodiment.  FIG. 4B  illustrates a section view of the propulsion unit, propulsion unit shroud,  40  cell battery container located above an electric motor. 
     
    
    
     Like reference numerals refer to like parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word “exemplary” or “illustrative” means “serving as an example, instance, or illustration.” All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims. For purposes of description herein, the terms “upper”, “lower”, “left”, “rear”, “right”, “front”, “vertical”, “horizontal”, and derivatives thereof shall relate to the invention as oriented in each individual figure. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     A Diver&#39;s Propulsion System is shown beginning on  FIG. 2A . This figure presents an isometric view  200  of a scuba tank harness or holder  230  being disengaged from the battery propulsion propellor unit. A scuba tank holder  230  has a groove or thread  240  that matches a corresponding thread or groove  260  on the inner lip of a propulsion unit  250 . These two cooperate to provide a water tight seal when the two corresponding threads or grooves  240 ,  260  are engaged together. Thus, the contents of the propulsion unit  250  including a cylindrical holder  210  for a battery pack, electric motor housing  220  and electrical connections can be protected from water seepage. The electric motor housing  220  has a propellor  280  attached thereto through the use of an armature  270 .  FIG. 2B  presents an isometric view of the rear portion of the battery propulsion propellor unit showing the propellor  280  protruding out the rear of the unit attached to the armature  270 . The location where the armature extends into and out of the back of the propulsion unit  250  are sealed with appropriate water tight rubber seals or similar materials. 
     As shown in  FIG. 3A , a conical propulsion unit  301  has a cylindrical battery holder  210  concentrically disposed about the electrical motor M  306  in the figure. Appropriate physical support for this cylindrical battery holder  210  is provided by having its external surface integrated with the inner walls of the conical propulsion unit  301  as shown; in this embodiment, the bottom edge of the cylindrical battery holder  210  is integrated with the inner surface of the conical propulsion unit  301 . The battery pack holder  210  includes a number of water-tight battery holders each holding a rechargeable battery  303  of predetermined voltage. The cylindrical battery holder  210  is shaped in the form of an annulus between an inner  304  and outer walls  302  with a plurality of cylindrical recesses for snugly receiving the corresponding batteries  303  arranged in alternating positive negative fashion. 
     This arrangement facilitates electrical connection between adjacent contacts on the top portion of the bottom surface of the battery holder  210  and between adjacent contacts on the underside of sealing annulus  307  shown in  FIG. 3B . This electrical connection scheme is described further below with respect to  FIG. 3D-E . Finally, there are plastic protrusions  305  that are integrated with the battery holder  210  that create multiple cylindrical cavities or slots for proper positioning of the batteries therein; these protrusions extend from the inside of the inner wall  304  to the inside of the outer wall  302 . 
       FIG. 3B  illustrates a section view through the propulsion unit  301 . This view better illustrates how the batteries  303  are arranged about the motor  306 . The bottom  308  of the cylindrical holder unit  210  is integrated with the inner surface of the conical propulsion unit  301  where the bottom  308  meets the perpendicular circular material of the cylindrical holder unit  210 ; in other words, the circumferential material forming the external boundary of the annulus holder. This view also shows the sealing annulus  307  of the cylindrical holder unit  210  having threads along its outer edge corresponding to the inner lip of surface  302  and it is understood that the inner circular edge of the annulus  307  has threads that correspond with similar threads found on the inner lip of surface  304 ; these threads have corresponding threads along the inner lips  302 ,  304  so as to effect a good seal with the holder unit thereof. Finally, this figure shows plastic or metallic supports S from the external surface of the electrical motor made from protrusions extending from the inner surface of the propulsion unit to the external surface of the motor M. 
       FIG. 3C  is an isometric view of a propulsion unit having a cylindrical battery holder unit  210  therein. Two types of seals for the battery holder unit  210  are described herein; a first having an screw-on annular sealing device and a second having an arrowhead connection arrangement. In a first embodiment, the rotational engagement between the sealing annulus  307  and the top of battery holder unit  210  acts to make a second watertight seal for protection of the batteries from water seepage. An alternative solution to the sealing of this battery holder unit  210  is to have a protrusion  314  extending from one side of the sealing annulus  307  as shown; this is user inserted into a slot (not shown) found along an inner edge of the larger radial circle at the top of the annular holder unit  210 . Thus, the engagement arrowhead  314  acts to secure the sealing annulus onto the top of the battery holder unit. The arrowhead  314  is inserted into a corresponding loop or slot extending from the inner lip of the larger radial surface of the battery holder unit  210 . This embodiment is completed by providing a water tight seal with the addition of appropriate rubber strips to help seal the contact points and edges as needed; the other embodiment using grooves also adds a rubber seal(s) as needed. 
       FIG. 3D  illustrates the electrical connections made at the bottom inner portion of the battery holder. At the bottom of the battery holder unit  210  is an inner portion  308  also in the shape of an annulus. This inner portion  308  has alternating metallic spring and flat contacts  316 − and  316 + embedded in slots as appropriate. Additionally, there are electrical wires  315  extending out through a hole in the side of the battery holder unit that is rubber sealed; thus, the wires are in wired contact with the motor in the center of the propulsion unit and actuate motion of the system. The spring and flat contacts  316 − and  316 + are arranged about the top inner side of the battery holder  210  in such a fashion that they form a circuit with the bottom of annulus sealing lid  307 . The contacts are numbered a, b, c, d, e, f, g, h, i, j on the top of the inner portion  308  and a′, b′, c′, d′, e′, f′, g′, h′, i′, j′ on the bottom of sealing annulus lid  307 . The connections alternate according to the needs of the circuit. 
       FIG. 3E  illustrates the electrical connections made at the underside or bottom portion of a sealing lid  307  for the battery holder. The annular sealing lid  307  has alternating metallic spring and flat contacts  316  embedded in slots as appropriate. The insertion of the batteries in an alternating fashion up then down then up and so on each in a single cavity of the battery holder unit  210  permits the series connection of the batteries to provide a working voltage for the motor. Thus the negative portion of a battery is in contact with a spring  316 − and its positive portion is in contact with a flat metallic plate  316 +. Finally, a wired connection  317  is made between adjacent contacts as appropriate to make the series connection. 
     The battery holder unit  210 , sealing annulus  307  and battery cavity protrusions  305  are made from a suitable plastic or similar materials. The electrical contacts are made from suitable metallic materials. 
       FIG. 4A  illustrates a top view of a  40  cell battery convention of another embodiment. 
     This embodiment  400  shows a cylindrical container  401  having  40  batteries  402  along with their cylindrical sub-spaces. Filler material  407  acts as spacing material between the different battery compartments and their inserted batteries. Sub spacers  408  and  409  are spaces formed to lessen the amount of weight of the holder  401 .  FIG. 4B  illustrates a section view of the propulsion unit, propulsion unit shroud,  40  cell battery container located above an electric motor. The motor M sits underneath the battery holder cell  401  and extends slightly therein to provide physical support to the holder unit. Again the holder unit  401  has integral support from the side inner walls of conical propulsion unit  404 . The motor is further supported by supports  406  that extend from the inner walls of propulsion unit  404  towards the surface of the motor M. The motor  405  armature extends out the bottom of the conical propulsion unit  404  thereby providing power to a propellor (not shown). Appropriate seals for the propellor armature and other components are understood in this and the other embodiment. 
     Thus, the embodiment taught herein have shown how to make a battery powered propulsion unit that overcomes the prior art problems of streamlining the bulky ungainly battery holder unit as the battery pack is now located within the confines of the propulsion unit instead of external to the user&#39;s body.