GB2056930A

GB2056930A - Rowing equipment

Info

Publication number: GB2056930A
Application number: GB8022614A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-08-22
Filing date: 1980-07-10
Publication date: 1981-03-25

Abstract

Rowing equipment is provided that allows the oarsman to face the direction of travel and maximize the seating capacity by rowing from the rear thwart. Each oar comprises two hinged sections 1 and 2 interconnected to promote an opposite angular movement one to the other the interconnection of the oar sections 1 and 2 being arranged so that the outer oar section will describe a greater angle than the inner oar section thus allowing a greater sweep of water in relation to inner oar angular movement than with a conventional oar, or the same sweep of water with a much reduced outer oar length to that of a conventional oar. The blade 7 can be arranged to feather automatically on the return stroke. The two hinged oar sections 1 and 2 can be folded together to provide a small package for easy conveyance. <IMAGE>

Description

SPECIFICATION Improvements in rowing equipment The invention relates to an improvement in rowing technique particularly concerning the means of propulsion.

According to the invention there is provided a means of propulsion for a rowing boat in which each oar has an inboard section and an outboard section, said sections coming together at a common zone of attachment to the boat and being interconnected so as to promote an opposite movement of the outboard section to that of the inboard section whereby to allow the oarsmen to face the direction of travel of the boat.

Both sections of the oar are connected to a further pivot through two short arms, this pivot being movable fore and aft of the boat in a suitable channel affixed firmly to the boat on the gunwale.

The two sections of the oar are pivoted to allow movement horizontal to the water the energy imparted by the oarsman to the inner section being transmitted to the outer section with blade through the two short pivoted arms. The two oar section can move relative one to the other only in a horizontal plane so that a downwards movement on the part of the oarsmen will result in a raising of the outer oar section with blade. This would apply during the reverse stroke.

The two short pivoted arms or links can be of unequal length to provide a mechanical advantage if required.

The oarsman can sit amidships on the centre thwart as is usual or, more importantly, he can sit on the rear thwart facing forward.

The advantages of the new equipment over current equipment are many and various but the freedom to face the direction of travel must be of paramount importance both from a convenience and safety aspect.

The wide centre thwart of an ordinary three thwart dinghy or yacht tender can accommodate three passengers facing forward free of the legs of the oarsman who will be on the rear thwart, and the forward thwart will retain its normal single capacity promoting an overall capacity of five persons instead of the usual four giving an increase of 25%.

It is likely that the existing rowlock holes situated in the gunwale aft of the centre thwart could be utilized forthe new equipment by the oarsman sitting on the rear thwart but new gunwale hole positions forward of the centre thwart would be required of a centre thwart oarsman sitting in this position to better balance his boat with no passengers.

The freedom to incorporate short arms or links of unequal length with the longer link on the inner oar section will provide a mechanical advantage that will allow a broad angle of sweep of the outer oar and blade without the requirement that the oarsman has to match this angle with the inner oar section.

It can be arranged that the working length of one or both short arms can be adjustable by the oarsman to suit his particular requirement. It could also be arranged that the two sections of oar can be quickly separated or folded to facilitate handling away from the boat and to provide an easier "package" for transportation such as in the boot of a motor-car.

An alternative mechanism would include toothed gears at each end of the oar section meshing at the zone of attachment to the boat and being of different diameters to provide the mechanical advantage described previously.

With the oar being produced in two sections linked and pivoted together it is now permissable to arrange that the outer section and the blade in particular can be feathered without any deliberate movement on the part of the oarsman in twisting his wrist. The blade can be rotatable to a near horizontal state on the outer oar section during the reverse stroke by arranging that the lower half of the blade is greater in area that the upper half. The greater resistance to the water of the lower half would cause it to rotate on the reverse stroke, the degree of rotation being limited to almost 90" by a circumferential stop on the outer oar section.The blade would revert to a vertical state on the propulsive or power stroke, again due to its asymetric balance that may be assisted by a light rotary spring device encouraging the normal position of the blade to the vertical.

The improvement in rowing equipment in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a plan view of a three thwart dinghy or tender with the improved rowing equipment fitted and illustrating the carrying capacity advantage. The oarsman is shown in View A at the end of the reverse stroke and in View B towards the end of the power stroke.

Figure 2 shows a plan view of a three thwart dinghy with the improved rowing equipment fitted and illustrating the mechanical advantage obtainable and the self-feathering blade. The oarsman is shown in View A at the end of the reverse stroke and in View B towards the end of the power stroke.

The advantageous seating arrangements afforded by the improved rowing equipment can be seen in Figure 1 with the oarsman on the aft thwart and the remaining two thwarts used to their capacity. In View B, Figure 1 the inner oar section 2 pivoted at 5 is being drawn towards the oarsman causing the end of short arm 4 to slide in channel 6 drawing with it the end of short arm 3 to which it is pivoted. In turn the other end of short arm 3 draws rearwards the outer oar section 1 to which it is pivoted causing the blade at the end of section 1 to transmit forward propulsive movement to the boat.

A reversal of this procedure during which the oarsman pushes forward the inner oar section 2 causes a reverse stroke with outer oar section and blade 1. The blade can be lifted clear of the water during the reverse stroke by the oarsman depressing inner section 2 at the same time as pushing forward.

An advanced version of the equipment would allow for a mechanical advantage to be brought about by arranging that short arm 4 shown in Figure 2, View B be made longer than short arm 3 thus exaggerating the angle of movement of oar section 1 over oar section 2 and providing a means of increas ing forward movement of the boat during each power stroke.

The need to deliberately iift the blade from the water during the reverse stroke could be eliminated by arranging that blade 7, shown in Figure 2, View A, could swivel on outer oar section 1 the blade moving to a rear horizontal state on the reverse stroke by arranging that the lower half of the blade be larger in section than the upper half causing greater resistance and encouraging a swivelling motion. A light spring biased to return the blade to a vertical state at the end of the reverse stroke would ensure correct blade positioning priorto the power stroke.

The materials for the improved rowing equipment could be traditional timber four inner and outer oar sections 2 and 1 respectively or they could be plastic or aluminium alloy section. Short arms 3 and 4 and channel 6 would preferably be metallic to ensure adequate rigidity and durability and blade 7 could be of aluminium alloy or plastic. Pivot pins would be non-ferrous to avoid the problem of corrosion that occur in a marine environment.

Claims

1. A means of propulsion for a rowing boat in which each oar has an inboard section and an outboard section, said sections coming together at a common zone of attachment to the boat and being interconnected so as to promote an opposite movement of the outboard section to that of the inboard section whereby to allow the oarsman to face the direction of travel ofthe boat.

2. A means of propulsion according to claim 1 wherein the inboard and outboard oar sections are interconnected by a linkage in the form of two arms that connect each section of oarto a common pivot moving within a fixed channel.

3. A means of propulsion according to claim 1 wherein the inboard and outboard oar sections are interconnected by a mechanism in the form of two toothed gears each of which is secured to a respective one of the oar sections, said gears meshing together in such a manner as to ensure said opposite movement.

4. A means of propulsion according to any one of claims 1 to 3 wherein the interconnection of said oar sections is such as to provide a mechanical advantage allowing a greater angle of movement of the outboard oar section to that of the inboard section.

5. A means of propulsion according to any preceding claim wherein the blade affixed to the outboard oar section is free to rotate through a limited arc whereby at the commencement ofthe return stroke of the oar the blade automatically rotates into a feathered position.

6. A means of propulsion according to claim 5 wherein the blade is free to rotate about the longitudinal axis of the oar.

7. A means of propulsion according to claim 5 wherein the blade is free to rotate about a vertical axis and offering no resistance on the return stroke of the oar.

8. A means of propulsion substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.

8. A means of propulsion according to any one of claims 1 to 4 wherein the blade affixed to the out board oar section comprises means supporting one or more flaps capable of moving from a substantially vertical plane into a trailing position relative to said support means whereby at the commencement of return stroke of the oar the blade is automatically feathered.

9. A means of propulsion according to any preceding claim wherein the complete oar can be bodily removed from the boat and the two oar sections folded together to allow easy conveyance to and from the boat.

10. A means of propulsion substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.

New claims or amendments to claims filed on 14 Nov 1980.

Superseded claims 1 to 10.

New or amended claims:- 1 to 8 CLAIMS

1. A means of propulsion for a rowing boat allowing the oarsman to face the bow of the boat and in which each oar has an inboard and outboard section the ends of which come together pivotally at a common zone of attachment to the boat and being mechanically interconnected so as to promote an opposite movement of the inboard section to that of the outboard section the interconnection being in the form of two arms or links each connected to an oar section and themselves coming together at a pivot moving within a fixed channel attached to the gunwhale of the boat.

2. A means of propulsion according to claim 1 wherein the interconnection of said oar sections is such as to provide a mechanical advantage allowing a greater angle of movement of the outboard oar section to that of the inboard section.

3. A means of propulsion according to any preceding claim wherein the blade affixed to the outboard oar section is free to rotate through a limited arc whereby at the commencement of the return stroke of the oar the blade automatically rotates into a feathered position.

4. A means of propulsion according to claim 3 wherein the blade is free to rotate about the longitudinal axis ofthe oar.

5. A meals of propulsion according to claim 3 wherein the blade is free to rotate about a vertical axis and offering no resistance on the return stroke of the oar.

6. A means of propulsion according to any one of claims 1 and 2 wherein the blade affixed to the outboard oar section comprises means supporting one or more flaps capable of moving from a substantially vertical plane into a training position relative to said support means whereby at the commencement of return stroke of the oar the blade is automatically feathered.

7. A means of propulsion according to any preceding claim wherein the complete oar can be bodily removed from the boat and the two oar sections folded together to allow easy conveyance to and from the boat.