Patent GB-1375313-A (GB)
IPC: A63B35/12
Filed: 1972-02-18
Abstract: 1375313 Diver transport vessel Y OHISHI 18 Feb 1972 [24 Feb 1971 25 March 1971 (2) 1 Dec 1971] 7549/72 Heading B7A [Also in Divisions H1 and H2] A diver transport vessel is powered by an electric motor 14 and has means for trimming the vessel to compensate for the weight of the diver, for avoiding leakage of electrolyte from the motor battery 29, and for protecting components against moisture and battery gases. The vessel has a fixed handlebar 2 bearing brackets 9 on which a watershield 10 is adj ustably mounted. The vessel propeller 16 rotates within a shroud 18 whose rear end may be downwardly directed, Figs. 11 and 12 (not shown), to provide an upthrust for balancing the weight of the diver. Alternatively, a deflecting flap, Figs. 9 and 10 (not shown), may be pivoted to the rear of the shroud. In order to protect electrical components against moisture they may be enclosed within sealed containers, Figs. 15 and 16 (not shown), lined with thermally insulating material and also containing moisture absorbent material. A high thermal conductivity metal plate is embodied in the hull to rapidly release heat from the hull interior to the surrounding water. An audible and/or visible warning of the accumulation of water in the vessel is given when sufficient water is present to bridge two electrodes, Figs. 17 and 18 (not shown). As illustrated in Fig. 3, battery gases may be collected by a manifold 23 and pass through a moisture absorber 25 to inflate and be retained in a bag 27. Periodical removal of a cap 30, which also covers a battery charging point, vents the battery gases from the bag 27. Gases may leave the battery cells through plugs screwed into the top of the battery. Gas in turn leaves the plugs through lateral openings covered by flexible sleeves, Figs. 27-34 (not shown), which allow passage of gas under pressure but resist the flow of electrolyte. As a further precaution, an electrolyte absorbing packing may surround the plugs. Having passed the sleeves, gases may be handled by a system of the Fig. 3 type or may pass through a non-return valve in the vessel hull. In a modification the battery is enclosed in a casing, Figs. 23 and 24 (not shown), surmounted by a swivel fitting to which is connected a flexible battery-gas exhaust pipe. This pipe leads to the battery charging point covered by the cap 30. An inflatable container such as 27 may be interposed in the pipe 146. Cables for distributing power from the battery to other electrical components may have a vinyl sealing compound forced between their component wires and the cable sheath, Fig. 20 (not shown), to prevent battery gases leaking along the cables. Where a cable passes through a bulkhead to a terminal box mounted on or integral with the bulkhead, Figs. 21 and 22 (not shown), the cable and the terminals are surrounded by compressed annular seals to prevent the migration of gases across the bulkhead. Electric circuitry is present, Figs. 35-37 and 40 (not shown), for switching the connection of the battery cells from a series to a parallel array if the output voltage drops below a predetermined level, so that overdischarge of the battery is avoided and effectively to utilize the remaining battery capacity at half speed operation of the motor. In addition, the motor current is sensed and the motor is stopped if overload is indicated.