GB2093783A

GB2093783A - Trailer articulated van

Info

Publication number: GB2093783A
Application number: GB8204386A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-02-27
Filing date: 1982-02-15
Publication date: 1982-09-08

Abstract

A caravan 2 has a forwardly extending part 4 with a towing hitch 3 disposed below the part 4 for engagement with a complementary part carried on the roof of a car. The caravan comprises a frame construction clad with floor, side, and roof panels and including lower side frame members on which wheels 21 are individually mounted. The complementary hitch part for carrying on the roof of a car has gutter clamps 40 and a male member, either a spring loaded bolt or a ball, for engaging in an aperture or socket in towing hitch 3. The gutter clamps may be articulated by pivots 42 to engage various curvatures of roof gutter, and their separation may be adjusted by pin and slot connectors 43. An aerofoil 47 is mounted for turning by the portion 4 and deflecting air foil the inter-vehicle space. <IMAGE>

Description

SPECIFICATION Improved trailer articulated van This invention relates to caravan constructions and towing arrangement for caravan constructions.

Known trailer caravans generally comprise a chassis and a box structure carried by the chassis.

Such a caravan is towed by a towing hitch on a simple or complex towing pole or structure at the end of the chassis, at chassis height. Thisarrangement connects the towing vehicle, usually a family car, at a low level whilst the caravan itself is commonly a high wide structure. This has a centre of gravity which is significantly higher than the top of the chassis even when the body is of light construction. The body also presents a substantial surface to wind resistance, and particularly to cross-winds, the centre of force of which is usually at the mid-point of the face against which it is blowing, significantly higher than the chassis, higher even than the intrinsic centre of gravity of the caravan, and frequently at a level comparable with the height of the towing vehicle.These factors combine to produce pitching and yawing when the caravan is towed and instability particularly in gusty conditions.

Manoeuvre is also difficult because turning radiuses are much higher than for a car on its own, rendering parking and negotiating narrow or twisting lanes difficult for the majority of drivers who only drive a car and caravan combination during holidays.

An object of the invention is to provide a caravan structure and towing arrangement which enabies the stability of the caravan to be improved particularly by eliminating or substantially reducing pitching and yawing movements.

Simply stated, the invention provides a caravan adapted to be connected to a towing hitch on the roof of a towing car.

The pivot thus provided is preferably forward of the rear axle of the towing vehicle, and the hitch may be carried on a roof attachment mounted on the roof of the car.

The caravan construction is preferably chassisless, the body of the caravan then being of box frame construction. Part of the caravan body may be built forwardly over the hitch, so that this part is over at least the rear part of the towing vehicle. The said forwardly built part may thus provide a sleeping and/or luggage compartment.

A preferred embodiment of the invention will be further described by way of example with reference to the accompanying drawings, wherein: Fig. 1 is a side elevation of a caravan according to the invention being towed by a car; Fig. 2 is a diagrammatic illustration of the structural framework of the caravan; Fig. 3 is a perspective view showing the car roof mountable towing hitch; and Fig. 4 is a sectional view of an alternative car roof mountable towing hitch.

Referring first to Fig. 1 of the drawings, the fundamental principle of the invention is illustrated in Fig. 1. A car 1 is towing a caravan 2 constructed in accordance with the invention by means of a roof level towing hitch 3. The pivot of the towing hitch 3 is located between the axles of the car and is carried by a forwardly extending part 4 of the caravan. This part can be used as a storage space or a sleeping space.

Fig. 2 shows the basic frame structure of the preferred embodiment of the caravan construction. The caravan has no chassis, instead the wheels 21 are each mounted via a spring suspension on a lower side member 22 of the boxframe construction.

Each side is completed by forward and after vertical members 23, 24 and a top side member 25, and also an intermediate longitudinal member 26. Inclined bracing members 27, 28 are also provided.

The forwardly extending part 4 is comprised at each side by an upper member 29 (shown sloping to provide a drag reducing profile) and a lower member 30 which is a prolongation of intermediate member 26. Transverse members connect the two side frames between the joint portions to complete the box. The caravan structure is then floored and clad with panels of the requisite types, including doors and windows, and fitted out with necessary furnishings.

The towing hitch 3 is supported on a reinforcing member extending between the lower members 30 for the forwardly extending part 4.

As shown in Fig. 3, a car roof mountable towing hitch comprises a gutter clamp 40 at each side.

Each clamp 40 has an inturned lower edge for gripping the car roof side guttering and is composed of two parts articulated by a pivot 42 to enable the clamp to gutters of various curvatures.

Each part of the clamps 40 is connected via a pin and slot connection 43 to a front or rear transverse member 44. The connections enable the towing hitch to be fitted on roofs of varying width, the pins or bolts on the parts of the clamps 40 being adjusted in the slots before tightening of nuts for fixing the width required.

A fore and aft bridge piece 45 extends between and is secured to the transverse members 44 by rivets for example, and this carries a reinforcing plate on which is mounted a 50 mm (2 inch) ball on a vertical post, for engagement in a corresponding socket in the caravan towing hitch 3.

An aerofoil 47 is swingably carried forwardly on the towing hitch mounting. Box slide guides 41 are pivoted on transverse members 44 and carry arms 48 themselves pivotally connected to plates 49 on aerofoil 47. Elastic rope 50 connected to the plates is additionally shown, Fig. 3, passed round a reeving spur 51 on traverse 44 for reduction of any "chatter", more especially when the car is used without the 'van, by taking a loop in the elastic 50 and doubling it over spur 51.

Referring now to Fig. 4, it will be seen that an alternative towing hitch assembly 3 includes a support plate 31 rigidly fixed to the underside of part 4. Plate 31 has a threaded aperture 32 which receives a threaded shaft 33 carried on a disc 34.

The height of the disc 34 can, by rotating the disc, be adjusted, the shaft 33 being screwed into or out of the aperture.

Disc 34 has a blind bore 35 coaxial with and opposed to the shaft 33. This bore 35 is adapted to receive a spring loaded bolt 36 braced upwardly by a spring 27. The bolt 36 penetrated an aperture in in a plate 38, spring 37 being seated around said aperture.

The bolt 36 can be retracted by a handle 36a and retained in retracted position against the force of spring 37 by rotating the handle to engage a shoulder 39.

Plate 38 with the bolt 36 is adapted to be mounted on and above a passenger car roof by means of supports 40 which include gutter clamps or the like securing means.

It will be appreciated that when disc 34 is properly positioned above plate 38, the bolt 36, can, when handle 36a is released from shoulder 39, be urged by spring 37 into bore 35 or plate 34.

The shaft 33 can counter threaded aperture 32 enable adjustment to be made for varying heights of car roof which vary somewhat from model to model.

Because the caravan is of box-frame construction, no chassis of conventional type is required and the wheels can be mounted on the lower longitudinal frame members 22 as described. Furthermore, the frame members 22 can be suspended from the wheels rather than supported by them, i.e. the wheel axles may be above the frame members as shown, so that for a given head room, inside the caravan, the overall height of the caravan may be reduced.

The caravan also has improved stability, because the centre of gravity of the caravan is below the level of the towing hitch, and can be arranged forwardly of the caravan wheels 21 so that the load of the caravan bears on the car 1 between the car wheels. In cross-winds, stability is also improved because the wind loading on the side of the caravan tending to overturn the caravan exerted above the level of the towing hitch is substantially matched by the load from the same source exerted below the level of the towing hitch which acts against overturning.

"Tracking" of the caravan is also improved with snaking, pitching and yawing of the caravan being virtually eliminated because of the caravan load being exerted evenly on the car chassis rather than as happens in many known caravans, being unstably balanced over the caravan's own wheels.

Manoeuvrability is also improved due to shortening of the caravan-car combination's turning radius.

Because sleeping space can be provided in the forwardly extending part 4 a caravan of given capacity may be of shorter wheel base than a conventional caravan constructed to provide the same accommodation, and the combined length of a car plus caravan much reduced. It is envisaged that a family saloon car and two berth caravan of the invention could be accommodated in a standard garage. With fore and art berths in the part 4, and none in the body of the caravan, such a caravan can also be made narrower than heretofore because no transverse berths are required, thus improving the rear view of the car driver, and the door is provided in the rear of the caravan, as is the case in Fig. 1.

In either mounting for the towing hitch the aerofoil 47 deflects the air stream passing from the car to the rearwardly sloping forwardly extending portion 4 of the 'van and takes away occasion for turbulence and suction drag otherwise engendered between the vehicles with consequent reduction in control, reduced fuel economy and hazard to passing road users.

Claims

1. A caravan adapted to be connected to a towing hitch on the roof of a towing can

2. A caravan according to claim 1 wherein the towing hitch is carried below a forward extension of the upper part of the caravan intended to be over at least part of a towing car.

3. A caravan according to claim 1 or 2 having a single pair of wheels, located towards the rear of the caravan whereby the centre of gravity is forward of the wheels.

4. A caravan according to claim 3 wherein the caravan body comprises a frame structure clad with floor, side, and roof panels, and the wheels are each separately mounted one at each side over a respective lower side frame member.

5. A caravan and car combination including a caravan according to any one of claims 1 to 4 towed by a car by means of a towing'hitch mounted on a roof rack of the car.

6. A towing hitch mountable on the roof rack of a car for engagement with a complementary towing hitch on a caravan according to any of claims 1 to 4, comprising a male member mounted on a frame having car roof gutter clamps at each side.

7. A towing hitch according to claim 6 wherein the separation of the gutter clamps is adjustable.

8. A towing hitch according to claim 7 wherein the adjustment is effected by pin and slot connections between the gutter clamps and the frame.

9. A towing hitch according to claim 6, 7 or 8 wherein each gutter clamp is articulated for engagement with gutters of various curvatures.

10. A towing hitch according to any one of claims 6 to 9 wherein the male member comprises a ball mounted on a vertical post for engagement in a socket in the caravan towing hitch.

11. A towing hitch according to any one of claims 6 to 9 wherein the male member is a spring loaded bolt biased into and retractable from an extended portion for engagement in a bore in the caravan towing hitch.

1 2. A caravan substantially as hereinbefore described and as illustrated in and described with reference to Figs. 1 and 2 of the accompanying drawings.

13. A caravan and car combination substantially as hereinbefore described, with reference to and as illustrated in Figs. 1 and 3 or 4 of the accompanying drawings.

14. A towing hitch adapted to be mounted on the roof of a car substantially as hereinbefore described with reference to and as illustrated in 10 Fig. 3 or Fig. 4.