Patent GB-1121341-A (GB)
Title: Improved apparatus for propulsion through water
IPC: A63B35/00
Filed: 1966-07-11
Abstract: 1,121,341. Swimming apparatus. L. ESNAULT. 11 July, 1966 [13 July, 1965; 27 June, 1966], No. 31031/66. Heading A6D. The invention relates to an apparatus to enable a person to travel through water, characterized in that it includes at least one tubular member 1 containing slidable sealing flap valves 24 carried by a rod 4 coaxial with the tubular member, and two tie members 2, 5 for respectively securing one pair of the user's members to the tubular member and the other pair of members to the rod, the sealing means being pivotally connected to the rod about an axis perpendicular to the longitudinal axis thereof and being provided with elastic means 28 which urge it towards its position wherein it completely seals the tubular member. In the apparatus as shown the user grasps tube 16 with both hands, his shoulders lodging against cushions 21a, 21b of shoulder-pieces 3 and his feet being slipped into the sandalfootrests 19, and by alternately bending and extending his legs, causes the shoulder pieces and the footrests to alternately move towards and away from one another, which in turn causes tubes 1 and pistons 24 to move in relation to one another. Assuming the apparatus to be initially motionless with rods 4 fully home in tubes 1 and flap-valves 24 closed (if they were not, elastic members 28 would immediately restore them into that position), then when the user stretches his legs flapvalves 24 thrust against the water, and because they meet heavy opposition therefrom tubes 1 are caused to move forward since their ends are open and the water therefore opposes only little resistance to this forward motion. Once the apparatus is in maximum extension, then if the user bends back his legs, flapvalves 24 fold back along the length of rods 4 as soon as the latter begin to penetrate deeper into the tubes, responsively to the water pressure that overcomes the resistance offered by restoring members 28. Were the apparatus to be motionless at the start of this phase, then the assemblies comprising flap-valves 24 and the corresponding rods 4 would merely penetrate into the tubes, which would then undergo a slight rearward shift in response to the resistance of the water exerted against the small cross-section offered by the flapvalves 24 when folded along the length of the rods. In order to permit of varying the speed attained and the effort to be made to reach a given speed, each tube 1 is provided, at its end into which rod 4 penetrates, with a variable-aperture nozzle 31 adjustable by a ring 32 rotatably mounted on tube 1 within easy reach of the user's hand. A rudder [44 Figure 12 not shown] is provided operable by tube 52 surrounding tube,6a forming part of the tie member 2, the tube 52 also serving as a hand grip. A modification is described consisting of a single cylinder tube and a single piston with associated rod (Figures 21 to 24 not shown). Another modification is described (Figures 25 to 32 not shown) in which floats are provided above two parallel cylindertubes joined by a head rest at one end a thrust bar provided with foot straps at the other.