GB2247436A - Boats and boat trailers - Google Patents

Abstract

A boat trailer includes a longitudinally extending frame member (21) and a transom plate (13). The frame member (21) and transom plate (13) are either attached to a boat so as to be launched with the boat, or integral parts of the boat. A towing hitch assembly (30) is attached to the forward end of the frame member (21) and road wheels (24) are releasably and pivotally mounted on the transom plate (13). <IMAGE>

Description

BOATS AND BOAT TRAILERS Field of the Invention This invention relates to boats and boat trailers and is concerned with the provision of improved designs of boats and of boat trailers.

Summary of the Invention According to a first aspect of the present invention there is provided a boat trailer comprising a longitudinally extending frame member, means for attaching a towing hitch to the forward end of the frame member, a transom plate connected to the rearward end of the frame member and pivot mounting means for the releasable attachment of road wheels to the transom plate.

The longitudinally extending frame member and the transom plate are preferably designed so that, when the boat is launched, the frame member and transom plate go into the water with the boat. The frame member and transom plate may thus be either attached to the boat if, for example, the boat is an inflatable craft, or an integral part of the boat if, for example, the boat is of fibreglass construction.

According to a second aspect of the present invention there is provided the combination of a boat and a boat trailer wherein the trailer includes a longitudinally extending frame member, to which a towing hitch can be attached, and a transom plate, to which road wheels can be attached, which frame member and transom plate are intended to be launched with the boat.

Brief Description of the Drawings Figure 1 is an end view of a dinghy and a trailer in their "towing" mode, Figure 2 is an end view of the dinghy and trailer in their "launching" mode, Figures 3 to 8 are perspective views illustrating components of the trailer, Figure 9 illustrates the bow of the dinghy and the associated towing hitch, Figure 10 illustrates a portion of the stern of the dinghy and one of the road wheels in its sea-going position, Figure 11 is a side view of the trailer alone, Figure 12 shows the stern of the dinghy and trailer fitted with "launching" wheels, and Figure 13 shows the use of a jack for removal or replacement of the road wheels.

Description of the Preferred Embodiments Figure 1 shows an assembly 10 comprising the combination of a dinghy and a trailer. The trailer includes a pair of inclined stays 11 on which pneumatic road wheels 24 are mounted, the stays 11 being carried by a transom plate 13. The stays 11 are in the form of square-section steel leg members which may be hollow but are preferably filled with a foamed plastics material, for example, a foamed polyurethane. The stays or leg members 11 are pivoted at points 14 within swivelling brackets 15 on pivot pins 16 and are retained securely in the road transport positions within guide brackets 17 through which securing cotters 18 can be inserted or removed as desired.

In order to ensure that the hingedly mounted stays or leg members 11 are retained securely in the required positions while the assembly 10 is being driven along the road, catches 19 (see Figure 5) are provided on each of the guide brackets 17.

The transom plate 13 is secured to the dinghy by means of four fixing bolts 20 which can readily be removed when required but which are provided with anti-vibration washers to prevent inadvertent loosening of the bolts in use. The design of the transom plate 13 is such that it can be used, basically, for any type of inflatable dinghy though the positions of the holes to receive the fixing bolts 20 will be determined by the design of the dinghy.

At the base of the transom plate 13, there is a boxsection steel housing member 23 which is welded permanently to the transom plate 13. This housing member 23 receives a hollowsection square steel frame member 21 as described in more detail below. The steel frame member 21 extends from the bow to the stern of the dinghy immediately beneath the undersurface of the dinghy and thus provides the additional function of a keel, improving the stability of the dinghy.

Figure 3 illustrates the positions at which the retaining brackets 15 and guide brackets 17 are mounted on the transom plate 13, the catches 19 mounted on the guide brackets 17 being shown in Figure 5. As will be appreciated from an examination of Figure 5, the catches 19, when in their locked positions (as shown) serve to conceal the gaffs in the brackets 17.

Figure 4 shows one of the hinged leg members 11 and its wheel 24 which is fitted with a pneumatic tyre. Each boxsection leg member 11 has welded to it a pair of solid cylindrical bars 19a which are so positioned along the length of the respective leg members 11 that, as the leg members 11 are pivoted into their road travel positions, the bars 19a will lift the catches 19 and will engage in the gaffs formed in the brackets 17 and catches 19 thereby holding the leg members 11 securely in the required positions.

The box-section housing 23, shown in Figure 3, extends at right angles to the plane of the transom plate 13 and is reinforced by a triangular support or brace plate 26 which is welded in position to the lower edge of the transom plate 13, the transom plate 13 being formed with two circular holes 28 containing one-way flap valves to allow the egress of water from within the dinghy.

After the transom plate 13 has been attached to the dinghy, the frame member 21 is inserted in the housing 23 and is secured therein by means of two high tensile steel bolts 27 which have captive anti-vibration nuts and washers to ensure that the frame member 21 cannot become detached as a result of vibration of the structure.

The box-section steel frame member 21, which may be hollow, but is preferably filled with a foamed plastics material, has aligned holes 22 at one end thereof to receive the fixing bolts 27 and, at its other end, is provided with a hitch assembly 30. The hitch assembly 30 includes a standard towing hitch 31 which, when the assembly is in its towing mode (as illustrated in Figures 6 and 11), can be engaged with a standard ball-type hitch member of a towing vehicle.

The hitch assembly 30 can be locked in its towing mode by means of a high tensile steel bolt 32 having a captive nut and washer. The hitch assembly 30 includes a hinge pin 33 which extends between two wing brackets 34 connected to a short boxsection element 33. Figure 6 shows the hitch assembly 30 in its towing mode whereas Figure 8 shows the hitch assembly 30 in its sea-going or stowed mode.

The height of the towing hitch 31 above the ground when in its towing mode is determined by the length of the short box-section element 35, this length being chosen in dependence on the type of dinghy which is to be towed. Figure 7 illustrates an optional support leg 60. This support leg 60 can be slid into the box-section element 35 and locked in position at the required height by means of a locking pin 61 which can be inserted in a hole 62 near the base of the element 35. When not in use, the support leg 60 can be removed and stowed within the dinghy.

When it is desired to move into the sea-going mode as illustrated in Figure 8, the box-section element 35 can be pivoted about the axis of pin 33 by removing pin 32 and then turning the assembly 30 into a position over the bow of the dinghy. This movement of the assembly 30 can be effected by means of a handle 43 which is fitted with a plastic ferrule 44, the handle 43 being welded in position between the two brackets 34. In an alternative arrangement, pins 32 and 33 are both removable to enable the hitch assembly to be removed for storage in, for example, the boot of a car.

Figure 4 shows the axle 39 on which wheel 24 is mounted, the dimensions of the axle 39 being determined by the parameters of the wheel hub. Figure 4 also shows the provision of a round steel bar 45 which is welded to each leg member 11, the bars 45 facilitating movement of the leg members 11 between their different positions. An extension 29 (see Figure 4) is provided on one branch of each bracket 17 and acts as a guide for the box-section leg member 11 as it enters the bracket 17.

A round bar 46 welded across the top of the two catches 19 enables both catches 19 to be lifted together when it is desired to disengage the leg member 11 from the bracket 17.

To improve the rigidity of each of the leg members 11 when in the sea-going mode, an eye-bolt 63 is employed to secure the mudguard of each wheel to its supporting backstay.

The eye of the bolt 63 can receive a rope which is threaded through the eye and then tied to the two side braces found on most dinghies.

The particular form of hitch 31 shown in the drawings is that which is commercially most readily available, though any suitable hitch can be employed. As shown in Figure 6, the hitch 31 is attached to the box-section element 35 by means of high tensile steel bolts 40 which are provided with anti-vibration nuts and washers.

As best illustrated in Figure 11, the square-section frame member 21 extends between the transom plate 13 and the hitch assembly 30 and is disposed beneath the dinghy so as to protect the underside of the dinghy if, for example, it is dragged over a shingle beach. Frame member 21 includes a curved portion on which are mounted locking catches 41 and a pintle 42. The locking catches 42 engage with the painter bracket on the dinghy and the pintle 42 permits the attachment of extra security ropes or straps which can be tied around the bow of the dinghy.

Figure 12 shows the use of alternative leg members lla.

The leg members 11a are tubular elements pivoted to the brackets 15 on the transom plate 13. At their lower ends, the leg members 11a are provided with large plastic spherical wheels 64. The leg members 11a will be used in instances where, for example, the dinghy has to be pushed over soft sand before it can be launched.

When the leg members 11a carrying the spherical wheels 64 are released from the positions illustrated in Figure 12, they can be hinged outwardly and upwardly into positions in which they lie against the inflated air bags of the dinghy. In this position, the spherical wheels 64 will provide additional buoyancy for the dinghy and, since they are much lighter than the normal road wheels 24 shown in, for example, Figure 1, the total "dead" weight will thereby be reduced.

Figure 13 illustrates the use of a jack mechanism 65 which may be required when the boat trailer has been driven to a position adjacent the launching position and it is desired to replace the normal road wheels 24 either by the spherical wheels 64 (for movement of the trailer across loose sand) or by alternative, lightweight wheels (not shown) for movement of the trailer across, for example, shingle.

The jack mechanism includes a main upright element from which a cylindrical pin 66 projects for engagement within the box-section housing 23. After the pin 66 has been engaged in the housing 23, the pin 66 can be raised or lowered relative to the upright by appropriate rotation of a handle 67. .THe rear of the dinghy can thus be raised clear of the ground to change the wheels, and then lowered again.

The particular design of trailer described above and illustrated in the drawings is, in effect, fitted to the dinghy so that the transom plate 13 and frame member 21, though detachable when required, will effectively remain permanently connected to the dinghy. The road wheels 24 and the hitch assembly 30 are detachable but are of such size that they can readily be placed within the boot of a car or within any other vehicle used to tow the dinghy to its launching position.

In a further embodiment of the invention, as applied to a boat produced from fibreglass, i.e. from a glass-fibrereinforced plastics material, normally a polyester resin, the frame member 21 and/or the transom plate 13 are integral parts of the boat structure. Thus, as the fibreglass rovings are applied to produce the boat, the frame member 21 and/or the transom plate 13 are placed within the mould and become embedded within the plastics material.

The transom plate 13, when embedded within the fibreglass, will provide an anchorage to which the pivot mountings, brackets and catches for the legs 11 can be attached. The frame member 21, when embedded within the fibreglass, will provide a structural element to the forward end of which a towing hitch assembly can be attached.

A boat produced from fibreglass and incorporating a frame member and transom plate in the manner indicated above will be very little different in weight as compared to a conventional fibreglass boat but will have the important advantage that, to enable it to be towed, all that will be required will be the fitment of a hitch assembly to the forward end of the frame member and the attachment of a pair of wheel assemblies to the transom plate.

Claims (9)

Claims:

1. A boat trailer comprising a longitudinally extending frame member, means for attaching a towing hitch to the forward end of the frame member, a transom plate connected to the rearward end of the frame member and pivot mounting means for the releasable attachment of road wheels to the transom plate.

2. A boat trailer according to Claim 1 in combination with a boat and in which the longitudinally extending frame member and the transom plate are so designed that, when the boat is launched, the frame member and transom plate go into the water with the boat.

3. The combination of Claim 2, in which the frame member and transom plate are attached to the boat.

4. The combination of Claim 2, in which the frame member and/or the transom plate is or are integral with the boat.

5. The combination of a boat and a boat trailer wherein the trailer includes a longitudinally extending frame member, to which a towing hitch can be attached, and a transom plate, to which road wheels can be attached, which frame member and transom plate are intended to be launched with the boat.

6. A boat trailer according to Claim 1, in which the pivot mounting means for the road wheels are positioned on the transom plate adjacent releasable catch means which cooperate with legs on which the wheels are mounted to hold the legs in their "road-driving" positions.

7. A boat trailer substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

8. The combination of a dinghy and a boat trailer substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

9. A fibreglass boat in which a longitudinally extending frame member and a transom plate are incorporated within the moulded structure of the boat, the frame member being provided at its forward end with means for attachment of a hitch, and the transom plate being provided with means for the mounting of road or other wheels, substantially as hereinbefore described.