GB2386352A

GB2386352A - A tilting trailer

Info

Publication number: GB2386352A
Application number: GB0205843A
Authority: GB
Inventors: Brian Lionel Bateson
Original assignee: BATESON TRAILERS Ltd
Current assignee: BATESON TRAILERS Ltd
Priority date: 2002-03-13
Filing date: 2002-03-13
Publication date: 2003-09-17
Also published as: GB0205843D0

Abstract

A trailer comprises a chassis 2, a deck 12 pivotally mounted on the chassis, and means (26 figure 2) for extending the length of the deck, where said means is moveable from a first position U to a second position L, wherein in the first position of the means the centre of gravity of the deck is to one side of the pivotal mounting 10 and in the second position of the means the centre of gravity of the deck is to the other side of the pivotal mounting. The means for extending the length of the deck may be a ramp which when lowered so as to be aligned with the deck causes the deck to tilt so that a load may be rolled on/off the deck. The deck may be locked to the chassis when in use, and a hydraulic/mechanical forcing means may be provided to force the pivoting motion of the deck.

Description

Trailers The invention relates to trailers.

5 There are many known types of trailer transporters for carrying roll-on, roll-off loads such as vehicles and the like. Some of these are tillable so as to make for easier loading and unloading. One type has a twin axle chassis on which a deck is pivotally mounted. The deck sits so that its centre of gravity is to the loading/unloading side of the pivotal mounting. As a consequence, in the unloaded condition, the deck is 10 urged into a tilted, inclined state for easier loading. When a front heavy vehicle, typically a car, is driven or moved on to the deck, the centre of gravity of the loaded deck shifts to the other, non- loadinglunloading side of the pivotal mounting, which urges the deck into a level, horizontal state for transporting. Driving or moving the car off the deck has the opposite effect, and urges the deck back into the tilted state.

15 The deck may be locked in the horizontal position, and a double-acting hydraulic piston and hydraulic pump are provided for damping the motion of the deck and for forcing it to move if necessary.

For any trailer transporter, it is preferable, from the point of view of towing, to have 20 the centre of gravity of the deck to the nonloading/unloading side of the pivotal mounting. This gives the trailer what is known as "nose weight". In effect, this means that there is a slight downward force acting on the trailer or hitch rather than an upward force. Nose weight makes for better stability when towing. Thus, if in the unloaded condition the centre of gravity of the deck is to the loading/unloading side 25 of the pivotal mounting, the trailer will have a tendency to be unstable when towed.

The invention provides a trailer comprising a chassis, a deck pivotally mounted on the chassis, means for extending the length of the deck, which means is moveable from a first position to a second position, wherein in the first position of the means 30 the centre of gravity of the deck is to one side of the pivotal mounting and in the

second position of the means the centre of gravity of the deck is to the other side of the pivotal mounting.

Hence, the extending means can be used to shift the centre of gravity of the deck so 5 as to change the tendency of the deck to pivot from one direction to the other. In one direction, the deck may be restrained by the chassis and the tendency to pivot may urge the deck into engagement with the chassis and to assume the same attitude, which will generally be level and horizontal. In the other direction, the deck may not be restrained and the tendency to pivot may urge the deck into a tilted, inclined state, 10 which makes for easier loading. The trailer may be provided with means for locking the deck in either the level or inclined states, and may be provided with means for forcing the pivoting of the deck. Thesc means may be either mechanical or hydraulic means or a combination of both.

15 The means for extending the length of the deck may be permanently attached to the deck by any means which enables it to be moved between two positions. For example, the extending means may be hingedly attached or telescopically attached.

Alternatively, the extending means may be detachable and moveable between an inactive, storage position and an active, attached position.

2V The deck preferably comprises a surface for load carrying. The surface may be continuous, for example in the form of a solid deck, or may be discontinuous, for example in the form of runners. The extending means also preferably comprises a surface for load carrying. The surface may be continuous or discontinuous. Further 25 preferably, in the second position of the extending means, the surface of the deck and the surface of the extending means are arranged such that the extending means extends the load carrying surface of the deck. Additional preferably, the surface of the deck and the surface of the extending means are arranged generally co-planar.

30 The invention will now be described, by way of example, with reference to the following drawings in which:

Figure 1 is a side view of a trailer according to the invention, shown in the deck-tilted state with platform extended; Figure 2 is a plan view of the trailer shown in figure 1; and S Figure 3 is a partial cross sectional view taken along the line m - m in figure 2.

With reference to figures 1 and 2, a transporter trailer according to the invention, indicated generally at 1, has a chassis 2 comprising a two part framework of square section galvanised steel members: the back part B. generally rectangularly shaped in 10 plan view, comprises side struts 5a, 5b, and a cross strut 7, and the front part A, generally triangularly shaped in plan view, comprises two converging front struts 9a, 9b. At the f ant, pointed end of the f ont part A there is provided a hitch 4 (shown in figure 1 only) for coupling to the trailer 1 to the tow bar of a vehicle (not shown).

The chassis 2 is suspended at the rear part B on twin, spaced apart axles 6a, 6b. At 15 the end of each axle 6a, 6b a wheel 8a, 8b is freely mounted. The twin axles 6a, Gb define a centre axis 10 which extends transversely of the chassis 2, midway between the rotational axes of the axles 6a, 6b.

Pivotally mounted on the chassis 2 is a deck 12 for supporting a load such as a 20 vehicle. The deck 12, generally rectangularly shaped in plan view, comprises a supporting f amework of two, main square section galvanized steel side members 1 6a, 1 6b between which are a number of square section steel cross members 1 8a- 1 8k.

The deck 12 is overlaid with board so as to provide a flat, continuous surface (not shown) for load carrying. The deck 12 also comprises two inboard side members 25 1 9a, 1 9b upon which the cross members 18 fixedly sit.

With further reference to figure 3, there are two pivotal mountings 20a7 20b, one at each of the ends nearest the axles of the chassis side members 5. Each mounting comprises a pin 22 extending transversely through and fixed to the corresponding 30 side member 5. The pin 22 also extends freely through the corresponding inboard side member 19 and a flange 24 projecting from a bridging member 21, bridging the

two inboard side members 19, in coplanar relationship with the rotational axis of the pivotable mountings 20 A platform 26 is hingedly attached at the loading/unloading end of the deck 12 The 5 platform 26, generally rectangularly shaped in plan view, is of the same width as the deck 12. The platform 26 comprises a supporting framework of two square section steel end members 28a, 28b between which are a number of square section steel longitudinal members 30a-30e overlaid with board (not shown), so as to provide a flat, continuous surface. The framework of the platform 26 is three dimensional to 10 the extent that five further ground members 32a-32e are provided, which, together with a corresponding one of the three inboard longitudinal members 30 and a spacer piece 34a-34e respectively form ground support frames, generally triangularly shaped in side view.

15 The platform 26 is hingedly attached to the deck 12. By virtue of its hinge attachment (not shown), the platform 26 is moveable between a first upright, transporting position U to a second, level unloading/loading position L. The platform 26 is held in the upright position U by locking pins (not shown), such that its longitudinal members 30 are generally perpendicular to the chassis side members 20 16 The platform,, 26 is held in the level position L, such that its continuous surface is generally coplanar with the continuous surface of the deck 12, by means of the ground members 32 extending beyond the spacer pieces 34 and engaging a stop 36 underneath the deck cross member 18a nearest the platform 25 In the unloaded condition, when the platform 26 is in the upright position, and the length of the leclc is not extended, the weight distribution of the deck 12 is such that its centre of gravity is in front of, in other words to the non-loading/unloading side of, the centre axis 10. This gives the trailer 1 nose weight and provides stability for towing. Moreover, the centre of gravity is in front of the pivotal mounting 14 so as 30 to urge the deck 12 into engagement with the chassis 2 and into the level, generally horizontal state.

Still in the unloaded condition, when the platform 26 is moved into the level position, and extends the length of the deck 12, the weight distribution of the deck 12 changes and is such that its centre of gravity is behind, in other words to the loading/unloading side of, the pivotal mounting 20. This results in the deck being 5 urged to tilt into an inclined state with the ground members 32 resting on the ground.

The deck 12 is then in a state ready for loading. If a vehicle or other front heavy load is then driven or moved on to the deck 12, the consequence will be to again redistribute the weight of the loaded deck such that its centre of gravity is in hont of he pivotal mounting 20 and the centre point 10. As a consequence, the deck will be 10 urged to assume the level position ready for transporting. The platform 26 can then be placed in the upright position.

When it comes to unloading the vehicle from the trailer 1, the platform 26 is first placed in the level position. The platform 26 then acts as an extension not only to the 1 S length of the deck 12 but also as an extension to the surface of the deck 12 such that the vehicle can be moved or driven backwards on to the platform 26 so as to redistribute the weight on the deck 12 and shift the contra of gravity to behind the pivotal mounting 20. As a consequence, the deck 12 is urged into the tilted position for unloading.

Hence, the platform 26 acts as means by which the deck 12 may be extended either to redistribute the self weight loading and thus the centre of gravity of the deck 12, or so as to facilitate redistribution of the loaded weight of the deck and thereby shift the centre of gravity.

Claims

1. A trailer comprising a chassis, a deck pivotally mounted on the chassis, means for extending the length of the deck, which means is moveable from a first position to a second position, wherein in the first position of the means the centre of gravity of the deck is to one side of the pivotal mounting and in the second position of the means the centre of gravity of the deck is to the other side of the pivotal mounting.

2. A trailer as described in claim 1 wherein the extending means in moving from the first position to the second position shifts the centre of gravity of the deck so as to change the tendency of the deck to pivot from one direction to the other direction.

3. A trailer as described in claim 2 wherein in the one direction the tendency to pivot urges the deck into engagement with the chassis and the deck is restrained by the chassis.

4. A trailer as described in claim 3 wherein when the deck is restrained by the chassis the deck and chassis assume the same attitude.

5. A trailer as described in any one of claims 2 to 4 wherein in the other direction, the deck is not restrained by the chassis such that the tendency to pivot urges the deck into a tilted, inclined state.

6. A trailer as described in any previous claim wherein the trailer is provided with means for locking the pivotally mounted deck on the chassis to prevent the deck from pivoting relative to the chassis.

7. A trailer as described in any previous claim wherein the trailer is provided with means for forcing the pivoting of the deck.

8. A trailer as described in claim 7 wherein the means provided for forcing the pivoting of the deck is mechanical or hydraulic.

9. A trailer as described in any previous claim wherein the means for extending the length of the deck is permanently attached to the deck by any means which enables the means for extending the length of the deck to be moved between the first and second positions.

10. A trailer as described in claim 9 wherein the means for extending the length of the deck is hingedly attached or telescopically attached to the deck.

11. A trailer as described in any one of claims 1 to 8 wherein the means for extending the length of the deck is detachable and moveable between an inactive, storage position and an active, attached position.

12. A trailer as described in any previous claim wherein the deck comprises a surface for load carrying.

13. A trailer as described in claim 12 wherein the extending means also comprises a surface for load carrying.

14. A trailer as described in claims 12 and 13 wherein in the second position of the extending means, the surface of the deck and the surface of the extending means are arranged such that the extending means extends the load carrying surface of the deck.

15. A trailer as described in claim 14 wherein the extending means acts as a ramp for roll-

on roll-off loading of the trailer when in the second position.

16. A trailer as described in either of claims 14 or 15 wherein the surface of the deck and the surface of the extending means are arranged generally co-planar when the extending means are in the second position.

17. A trailer as described in any one of claims 14 to 16 wherein the extending means acts as barrier to roll-off unloading of the trailer when in the first position.

18. A trailer as described in any previous claim wherein when unloaded and the means for extending the length of the deck is in the first position the centre of gravity is forward of the centre axis of the trailer.

19. A method of using a roll-on roll-off trailer, the trailer comprising a chassis, a deck pivotally mounted on the chassis, means for extending the length of the deck, which means is movable from a second position to a first position, the method comprising the steps of moving the means for extending the length of the deck from a second position wherein the centre of gravity of the deck is to one side of the pivotal mounting and the tendency to pivot urges the deck into a tilted, inclined state to a first position of the means wherein the centre of gravity of the deck is to the other side of the pivotal mounting such that the deck tilts into engagement with the chassis and is restrained by the chassis locking the deck in position on the chassis such that a nose weight is present on a hitch of the trailer in normal unloaded use.