this particular example is intended as a light , quickly detachable , easily transportable interpretation of the basic concept , comprising three main component parts , a self contained engine unit , a main body assembly and a handle bar and control lever assembly . referring to fig5 the self contained engine unit is a single cylinder internal combustion engine with a recoil starter 1 and a magneto 2 of orthodox design facing forwards and an enclosed propeller ( not shown ) mounted on the mainshaft facing rearwards , drawing in water at the front 3 and expelling a water jet rearwards through a tunnel 4 . the engine unit includes and is attached to a one piece molded plastic tank 5 that incorporates an air tank 6 with a snorkel 7 at the front , through which the carburetor breathes , and a separate fuel tank 8 at the back . access to the spark plug 19 is through a hole molded in the center of the tank 5 . the engine unit also includes a cradle 9 , that attaches the front of the tank 5 to engine mounts located at the bottom of the crankcase magneto housing 10 . this engine unit is of the type fully described in u . s . pat . no . 3 , 890 , 920 and any further description is thought not to be necessary . referring to the drawings , the main body 11 is a hydrodynamically streamlined component manufactured from a plastic foam which is light , durable , possesses a high degree of buoyancy , is rigid enough to maintain its shape , but is comfortable in use and energy absorbing in the event of a collision . it is one meter long , 0 . 4 meter wide at the rear , narrowing towards the front with a rounded streamlined nose . the rear is chamfered and dished in shape 12 to merge and blend with the upper chest area of the person being propelled . there is a large hole ( not shown ) approximately in the middle , shaped to be a close fit over and around the fuel / air tank 5 of the engine unit . there is a top plate 13 manufactured from rigid plastic sheet fixed to the top of the main body 11 with four nylon screw type fixings 14 . the top plate has two holes ( not shown ), one that locates around the air tank threaded top 15 and the other that locates around the fuel tank threaded top 16 . screwing down the snorkel air tank cap 17 , and the fuel tank cap 18 , fixes the top plate 13 and therefore the main body 11 , to the fuel / air tank 5 of the engine unit . there is a larger hole ( not shown ) in the top plate 13 between the other two , that gives access to the engine units spark plug 19 . to complete the main body assembly , there is a top pad 20 made from the same material as the main body 11 , which acts as a spacer between the main body and the handle bar assembly , covers the snorkel cap 17 , the spark plug access hole , and the fuel cap 18 . it also adds extra buoyancy and provides a comfortable chin or head support for the person being towed . there is a nylon securing strap 21 , that wraps under the fuel tank 8 , goes right through the main body 11 and top plate 13 and buckles over the retains the top pad 20 . the handlebar assembly consists of a set of handlebars 22 , a control lever on each end 23 and 24 , a support bracket on either side 25 , a decorative central cover 28 and a control cable 26 and 27 from each control lever . the support brackets are fixed to the handlebars at a slightly greater width than the width of the main body top pad 20 . the handlebar assembly is fitted to the towing device by pushing each support bracket 25 through a hole ( not shown ) in the forward end of the main body top plate 13 , one on either side of the top pad 20 , right through the main body 11 , and sliding them into a spring loaded retaining clip 29 screwed and fixed on each side of the engine unit cradle 9 . the right hand control lever 24 and its control cable 26 , are connected to the accelerator lever on the carburetor . the left hand control lever 23 and its control cable 27 , is a safety device that in the event of the person being towed , inadvertently letting go of the towing device , would either cause the towing device to go round in a continuous circling motion , or alternatively would stop the engine . the preferred method would be to have the lever and cable connected to a spring loaded rudder ( not shown ) so that when the lever is pulled right back to the handlebar , the rudder would be in a straight line with the towing device , and if the lever was accidentally released , the rudder would spring to one side out of line causing the towing device to move in a continuous circle until retrieved by the user . the advantages of the present invention over prior art can now be seen to be , number 1 , the drag factor and self limiting effect caused by the persons arms , shoulders and chest being in the water has been overcome . number 2 , with the present inventions single entity concept , its closeness and overlapping with the person being towed is such that steering is executed with the shoulders or upper arms , not the hands , by leaning or applying body weight to the relevant side of the rear end of the towing device . the &# 34 ; handlebars &# 34 ; are in a fixed position and their function is simply a means of holding the towing device , and operating the control levers . it has been found in fact that in use the hands wrists and arms can be relaxed completely , consistent with the fingers remaining curled around the handlebars . therefore the tiring effect with prior art of having to steer and direct continuously with hand , wrist or arm pressure has also been overcome . number 3 , the related tiring effect in rough water conditions , or water conditions where waves exist , of the level of the towing device and the level of the person constantly changing in relation to each other is substantially reduced since the hands , arms , shoulders , chest and head of the person being towed and the said towing device , move up and down together , either up together or down together . number 4 , where with prior art , the head is not positively supported above the water surface , with the present invention , when the person is holding the handlebars or means of holding in the normal operating position , even if the person is incapacitated or semi - conscious for any reason , their head would still be positively supported above the water surface , both with the towing device moving or stationary . number 5 , the unique benefit believed to be added , mentioned earlier , which could be the present inventions most important advantage , is a variable stretching or extending force applied to the torso and spine of the person being towed . this is caused by the propulsion force of the towing device pulling the hands , arms , and shoulders of the person in a forward direction , the lack of , or neutrality of water drag around their chest area , so that the force of the water drag pulling rearwards on their lower body , from the waist down , caused by the propelling water jet and surrounding water is substantially greater than any water drag on their upper body . the force of the water drag on their lower body can be increased or decreased simply by varying the angle and position of their feet in relation to the propelling water jet , instead of just letting them trail in line . coupled with the degree of relaxation and infinitely variable movement possible in water , either from steering from side to side or the movement up and down created by waves , the overall effect has been found to be of significant benefit in reducing back pain in a person who suffers with this condition . in conclusion , the present invention provides a water surface towing device that is not limited by poor hydrodynamic efficiency , and therefore has the capability to travel considerably faster than prior art in a smooth relaxed manner , with significantly less physical effort required and since the head is always supported , with a high degree of safety . it is fun to use , and should prove to be a valuable therapeutic aid . it should be noted that the basic and essential concept of the present invention of regarding the towing device and the person being towed as a single entity for hydrodynamic purposes , is capable of interpretation in various ways , including different constructions and materials and ranging from sophisticated permanently assembled examples to relatively simple , light , quickly detachable , easily trasportable examples . therefore , while a relatively simple , quickly detachable example has been illustrated herein , it is appropriate that the appended claims be construed broadly and in a manner consistent with the spirit and scope of the invention herein .
a self powered aquatic device that will tow a person through and across a water surface , where in use , most of the persons body is essentially in the water , but where the head and arms are supported above the surface in a manner that could be described as a powered alternative to swimming but with a higher speed capability . the towing device and the person form an essentially single combined hydrodynamically streamlined shape that diverts or guides surrounding water underneath or around the persons chest area in a smooth flow . steering is executed with the upper arms or shoulders , instead of the hands , and a variable stretching or extending force is applied to the persons torso and spine , controlled by the person .