GB2171662A - Pedal-powered boat - Google Patents

Abstract

A pedal boat consists of a bicycle style transmission 10, 14, 13 coupled through a long propeller shaft 16 to a power boat type propeller and housed within a lightweight and streamlined hull. As the gearbox assembly is well forward in the hull a very long propeller shaft is used which gives an excellent thrust line. In addition, as the forward end is above the water line the need for a water seal and consequent friction is removed. The above arrangement is fitted in two basic hull types, viz a small planing hull designed for 'pottering' or racing on sheltered waters and a long canoe style craft which is fitted with equipment for long distance travel on inland waterways. The hull may terminate with a bulkhead to which bow sections of different length can be attached. <IMAGE>

Description

SPECIFICATION Pedal-powered boat This invention relates to a pedal powered propulsion system used in conjunction with a high efficiency planing of semi- displacement hull of lightweight construction.

Pleasure boats utilising arm or leg power are a familiar sight around our coastline and on boating lakes.

However, due to the method of propulsion, usually rotary paddles driven by a primitive crank, a large percentage of the available power is lost. In addition, the shape of the hull and their ungainly size and weight severely limit the performance.

To overcome the above this invention employs the combination of an efficient power-boat type propeller on a long shallow angled propeller shaft and stern tube assembly, driven by a bicycle style transmission (through an appropriate gearbox) and housed within a lightweight and highly streamlined hull.

The craft described here, with reference to the drawing Figure 1 embody the following general features.

A set of pedals and chainwheel 10 of the type used on a full size bicycle are supported by a 'bottom bracket' type bearing 11 from the same source. The pedals are further provided with a full length adjustable support and straps to increase efficiency and reduce fatigue. This assembly is mounted on a framework 12 which carries at its forward end a spur gearbox to direct the drive through 90 degrees 13. The input shaft of the gearbox has a small sprocket which is arranged in line with the chain wheel to enable a chain 14 to couple them together. A multiple gear arrangement may be used.

The output from the gearbox is taken through a simple universal joint 15 to allow for hull flexing.

The whole assembly is fastened in the hull 18 with the gearbox at the forward end and the output shaft pointing to the stern. This arrangement enables a long propeller shaft 16 and stern tube 17 to be used at a small angle to the horizontal, thus providing an efficient thrust line. In addition, the forward end of the stern tube is above the water line and therefore does not require a water seal (i.e. stuffing box) which would increase shaft friction. The propeller shaft is supported at the forward end by a standard ball race and at the stern by a water lubricated bearing. The skeg 19 is gradually tapered to a knife edge in order to reduce turbulence in the lee of the stern tube to a minimum whilst providing adequate support.

The above arrangement would be fitted for example in the following:a) A small lightweight, high speed planing hull which could be raced on sheltered waters.

b) A larger semi-displacement canoe style craft to enable 2 or more people to travel long distances on inland waterways. A storage area for camping equipment or other baggage would be incorporated in the design. This craft could utilise 1 or more sets of pedals.

In order to cater for different size requirements the forward end of the boat would terminate in a bulkhead and large dowel tubes would enable different length bow sections, each with its own bulkhead to be attached. The extra weight of the longer craft would to some extent automatically be compensated for by the increased water line length.

The integral bulkheads add rigidity and obviate the need for a water seal.

For protection in wet weather a 'covered wagon' style transparent cover would be supported by lightweight style hoops. The hoops would slide in a captive groove on each side of the hull and be slid to the rear and laid down when not in use.

Steering would be accomplished with a cable or lever operated rudder, the size, position and profile of which would be a compromise between propellor blanketing and turning response.

1. A pedal boat consisting of the combination of a highly efficient bicycle style power transmission system driving a long shallow angled propeller shaft and stern tube assembly and housed within a lightweight streamlined hull.

2. A pedal boat as in claim 1 utilizing a long canoe style hull.

3. A pedal boat as in claim 2 wherein means are provided to alter the overall length of the hull by providing different length lug-in bow sections.

4. A pedal boat as in claims 1 to 3 which is provided with storage space for camping gear or other equipment.

5. A pedal boat as in any preceding claim wherein protection from wet weather is provided.

6. A pedal boat as in any preceding claim but incorporating one or more sets of pedals driving one or more propellers.

7. A pedal boat as in claim 1 but incorporating a planning hull form.

8. A pedal boat as in any preceding claim but incorporating a twin or multiple hull form.

9. A pedal boat substantially as any described herein with reference to the accompany drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Pedal-powered boat This invention relates to a pedal powered propulsion system used in conjunction with a high efficiency planing of semi- displacement hull of lightweight construction. Pleasure boats utilising arm or leg power are a familiar sight around our coastline and on boating lakes. However, due to the method of propulsion, usually rotary paddles driven by a primitive crank, a large percentage of the available power is lost. In addition, the shape of the hull and their ungainly size and weight severely limit the performance. To overcome the above this invention employs the combination of an efficient power-boat type propeller on a long shallow angled propeller shaft and stern tube assembly, driven by a bicycle style transmission (through an appropriate gearbox) and housed within a lightweight and highly streamlined hull. The craft described here, with reference to the drawing Figure 1 embody the following general features. A set of pedals and chainwheel 10 of the type used on a full size bicycle are supported by a 'bottom bracket' type bearing 11 from the same source. The pedals are further provided with a full length adjustable support and straps to increase efficiency and reduce fatigue. This assembly is mounted on a framework 12 which carries at its forward end a spur gearbox to direct the drive through 90 degrees 13. The input shaft of the gearbox has a small sprocket which is arranged in line with the chain wheel to enable a chain 14 to couple them together. A multiple gear arrangement may be used. The output from the gearbox is taken through a simple universal joint 15 to allow for hull flexing. The whole assembly is fastened in the hull 18 with the gearbox at the forward end and the output shaft pointing to the stern. This arrangement enables a long propeller shaft 16 and stern tube 17 to be used at a small angle to the horizontal, thus providing an efficient thrust line. In addition, the forward end of the stern tube is above the water line and therefore does not require a water seal (i.e. stuffing box) which would increase shaft friction. The propeller shaft is supported at the forward end by a standard ball race and at the stern by a water lubricated bearing. The skeg 19 is gradually tapered to a knife edge in order to reduce turbulence in the lee of the stern tube to a minimum whilst providing adequate support. The above arrangement would be fitted for example in the following:a) A small lightweight, high speed planing hull which could be raced on sheltered waters. b) A larger semi-displacement canoe style craft to enable 2 or more people to travel long distances on inland waterways. A storage area for camping equipment or other baggage would be incorporated in the design. This craft could utilise 1 or more sets of pedals. In order to cater for different size requirements the forward end of the boat would terminate in a bulkhead and large dowel tubes would enable different length bow sections, each with its own bulkhead to be attached. The extra weight of the longer craft would to some extent automatically be compensated for by the increased water line length. The integral bulkheads add rigidity and obviate the need for a water seal. For protection in wet weather a 'covered wagon' style transparent cover would be supported by lightweight style hoops. The hoops would slide in a captive groove on each side of the hull and be slid to the rear and laid down when not in use. Steering would be accomplished with a cable or lever operated rudder, the size, position and profile of which would be a compromise between propellor blanketing and turning response. CLAIMS

1. A pedal boat consisting of the combination of a highly efficient bicycle style power transmission system driving a long shallow angled propeller shaft and stern tube assembly and housed within a lightweight streamlined hull.

2. A pedal boat as in claim 1 utilizing a long canoe style hull.

3. A pedal boat as in claim 2 wherein means are provided to alter the overall length of the hull by providing different length lug-in bow sections.

4. A pedal boat as in claims 1 to 3 which is provided with storage space for camping gear or other equipment.

5. A pedal boat as in any preceding claim wherein protection from wet weather is provided.

6. A pedal boat as in any preceding claim but incorporating one or more sets of pedals driving one or more propellers.

7. A pedal boat as in claim 1 but incorporating a planning hull form.

8. A pedal boat as in any preceding claim but incorporating a twin or multiple hull form.

9. A pedal boat substantially as any described herein with reference to the accompany drawing.