GB2118120A - Muscle-powered, propeller- driven boat having an hydrostatic transmission - Google Patents

Abstract

A pair of crank handles (1) drive an hydraulic pump (10) which draws oil from tank (11) to supply hydraulic motors (15) which drive screw propellers (17). The motor housings are pivoted on vertical pivot shafts which are coupled together via steering pulleys (20) and an endless belt. A steering lever controls draw strings which enwrap one of the steering pulleys. The transmission includes a reversing valve (14). Buoyancy floats are extendible by hydraulic jacks under the control of a pressure fluid flow reversing valve (21). <IMAGE>

Description

SPECIFICATION Non-powered, propeller-driven boat having an hydrostatic transmission The present invention relates to a nonpowered, propeller driven boat having an hydrostatic transmission.

Non-powered boats are conventionally propelled with oars. Rowing a boat requires skill and a great deal of physical effort. A rowing boat is not easy to turn in a confined space since room is required to manipulate the oars. This creates difficulty when approaching other boats or a landing stage and oars can easily be broken in such circumstances.

Pedal boats have been designed, generally for pleasure purposes, but these are not really satisfactory because their centre of gravity is too high and the boat tends to be unstable unless special precautions are taken, for example by providing twin hulls.

A screw-propeller driven boat may be satisfactorily designed as to be stable and turn in a narrow space but this normally involves the provision of an engine which is expensive and requires considerable maintenance.

The present invention provides a non-powered boat having at least one screw propeller and an hydrostatic transmission coupling manually operable means to drive the propeller.

A specific embodiment of the present invention will now be described by way of example and not by way of limitation with reference to the accompanying drawings in which: FIG. 1 is a side elevation of a boat in accordance with the present invention; FIG. 2 is a plan view of the boat shown in Fig. 1; FIG. 3 shows a detail of the construction of manually operable means and also extendable and retractable buoyancy means; FIG. 4 is a diagrammatic plan view showing the hydrostatic transmission coupling the manually operable means to drive two screw propellers of the boat; FIG. 5 shows a detail of construction of boat steering means provided in association with the screw propellers; FIG. 6 is a plan view corresponding with Fig. 2 and showing the buoyancy means extended on each side of the boat; and FIG. 7 is a diagram of operating gear for extending and retracting the buoyancy means.

With reference now to the accompanying drawings, a pair of crank handles 1 mounted respectively at opposite sides of the boat astern of the thwart are connected via chain-and-sprocket wheel drives 2, 3, 4 and 6, 7 to drive a shaft 8 of a hydraulic pump 10 which is connected to draw hydraulic fluid from an oil tank 1 The shaft 8 mounts a flywheel 9. A change-over valve 14 is mounted at the starboard side of the boat. The function of the valve 14 is to determine the direction of rotation of the screw propellers 1 7 to drive the boat forwardly or in reverse.

When the crank handles 1 are rotated forwardly from the thwart, that is to say, clockwise as seen in Fig. 1, oil is pumped by the pump 10 from the tank 11 through the conduit 12 to the valve 14.

When the valve 14 is set in the forward drive position, oil is supplied, under pressure, via the conduit 1 4a first to a reversible hydraulic motor 1 5 and then to a further reversible hydraulic motor 15' via conduits 1 4b and 14c, the oil being returned to valve 14 via a conduit 1 4d and thence via a conduit 1 3 to the tank 11. The motors 15, 15' are driven in corresponding directions to rotate the motor shafts 1 6, 1 6' mounting the screw propellers 17, 17' respectively to rotate the propellers in a forward drive direction.When the valve 14 is set to a reverse drive position oil under pressure flows first to motor 1 5' in the reverse direction via conduit 1 4d and then to motor 1 5 via conduits 1 4c and 1 4b to drive the motors 1 5, 1 5' in the reverse direction, the oil exhausting from motor 1 5 returning to tank 11 via conduit i 4a, the valve 14 and conduit 13.

In an alternative arrangement, the valve 14 may supply the motors 1 5, 1 5' with oil under pressure in tandem and in a corresponding direction depending on the selling of the valve 1 4.

The housings of the motors 1 5, 1 5' are mounted to turn on vertical shafts 50 journalled in the boat hull (see Fig. 5), the shafts carrying pulleys 20, 20' coupled together by an endless belt 1 9. By rotating the pulleys 20 in unison via the belt 1 9 the direction of movement of the boat is controlied, the screw propellers 1 7, 1 7' being correspondingly pointed at an angle to the foreand-aft line of the boat hull to cause the boat to turn. A pivoted direction control lever 1 8 is coupled, at a point remote from its pivot, to draw strings 18' which alternately wrap the starboard pulley 20 to turn the pulley depending upon the direction of movement of the lever 1 8 fore or aft.

In the central position of the lever 18 the propellers 17, 17' are set to propel the boat directly ahead or directly astern, the indicator on the pulley shown in Fig. 5 then being set to "O" on the circular scale. The lever 1 8 is movable forwardly to rotate the pulleys 20 anti-clockwise in Fig. 5 through 900 for a full forward movement of the lever 18 and vice versa so that, coupled with forward and reverse drive of the propellers, turning of the boat in a very narrow space can be accomplished.

The boat is equipped with buoyancy floats 25, 25' extendable and retractable between the full line and broken line positions shown in Fig. 6 by the operation of double acting hydraulic jacks 23, 23' (see Fig. 7). The floats are mounted on rods 26', 26", 26"' and 26"" slidable in sleeves 24, 24', 24", 24"' carried in board of the boat hull.

The jacks 23, 23' are supplied with oil under pressure from the pump 10 via an oil flow direction reversing valve 21 to extend or retract the floats 25, 25' as desired. When extended, the floats 25, 25' assist in preventing overturning or capsizing of the boat. When retracted, the boat may be propelled at a faster speed.

The hydraulic pump 10 and the hydraulic motors 1 5, 1 5' may take any known or convenient form.

The motors 1 5, 1 5' are equipped with flexible oil conduits to allow the motor housings to turn freely under the control of the lever 18. The lever 1 8 conveniently has set positions to allow the boat to be propelled and steered single handed.

Alternatively, the steering lever 1 8 may be controlled by a passenger.

The advantages of a boat as described with reference to the accompanying drawings are that it is noiseless and may be propelled by unskilled persons with less physical effort than by rowing.

The boat is less liable to damage and may be readily manoeuvred in a confined space. Also, the boat has stabilizing floats which are readily brought into use or retracted as desired.

Claims (12)

1. A non-powered boat having at least one screw propeller and an hydrostatic transmission coupling manually operable means to drive the propeller.

2. A boat as claimed in claim 1 in which twin screw propellers are provided coupled to be driven by the manually operable means.

3. A boat as claimed in claim 1 or 2 in which the hydrostatic transmission comprises an hydraulic pump and an hydraulic motor, the motor is connected to drive the propeller and the motor housing is pivotally mounted to steer the boat.

4. A boat as claimed in claim 3 in which the motor housing has a pivot mounting shaft, the pivot mounting shaft mounts a steering pulley and the steering pulley is rotatable by movement of a pivoted steering lever to steer the boat.

5. A boat as claimed in any preceding claim in which the hydrostatic transmission comprises a reversible hydraulic motor and valve means is included to reverse the direction of drive of the motor.

6. A boat as claimed in any preceding claim having buoyancy floats extendible and retractable by the operation of hydraulic jacks and means to supply the jacks with pressure fluid from pump means forming part of said hydrostatic transmission.

7. A boat as claimed in claim 6 in which the jacks are double acting jacks and said pressure fluid supply means includes a pressure fluid flow reversing valve.

8. A non-powered boat having twin screw propellers, an hydrostatic transmission comprising an hydraulic pump and for each propeller an hydraulic motor connected to drive the propeller, the hydraulic motors having pivotally mounted motor housings coupled together to perform corresponding pivoting movements to point the propellers in corresponding directions in order to steer the boat, and manually operable means for powering the transmission.

9. A boat as claimed in claim 8 in which the manually operable means comprises at least one crank handle.

10. A boat as claimed in claim 9 in which the crank handle is arranged to drive the hydraulic pump shaft via a speed increasing chain-andsprocket drive.

11. A boat as claimed in claim 9 in which the hydraulic pump shaft carries a flywheel.

12. A non-powered boat substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.