GB2137940A - Container Trailer - Google Patents

Abstract

A semi-trailer designed to carry a container comprises a main frame (10) and a sub-frame (19) which are capable of relative sliding movement in a horizontal, fore-and-aft direction within limits established by stops (27', 27'' and 28') so that with the sub-frame (19) releasably locked in the position shown the trailer extends beyond the rear end of the container, which upstands from the rear end (11) of the main frame (10); in order to gain unobstructed access to the doors in the rear end wall of the container when the trailer is stationary or parked the sub-frame (19) is held stationary by braking the wheels (18) supporting it and the main frame (10) carrying the container is moved rearwardly until the rear end (37) of the sub-frame (19) is substantially aligned with the rear end (11) of the main frame (10) in the same vertical plane, so that the trailer no longer projects beyond the rear wall of the container. <IMAGE>

Description

SPECIFICATION Container Trailer This invention relates to an improved trailer for the transport by road of containers of fixed dimension when articulated to a tractor vehicle.

Under the new regulations permitting gross carriage weights of up to 38,000 kgs a trailer 8,762 mm long is required to carry a container with a standard length of 6,096 mm. If the centre of gravity of the load is to act 4,038 mm from the rear end of the trailer the rear doors of the container will be 990 mm forward of the rear end of the trailer. This means that access to the rear doors of the container while on the trailer will be obstructed by a rear end portion of the trailer projecting 990 mm beyond the container.

To overcome this problem there is provided, in accordance with the present invention, a vehicle having a cargo-carrying main frame and a supporting wheel assembly the position of which relative to the main frame is adjustable longitudinally of the vehicle.

The wheel assembly is preferably mounted on a sub-frame which has limited horizontal sliding movement relative to the main frame, means being provided to lock the sub-frame in at least one of its limit stop positions relative to the main frame.

A trailer vehicle in accordance with the invention has means at a forward position for articulated connection of the trailer to a tractor vehicle and a rear wheel assembly which is movable toward and away from said articulation means.

The sub-frame is preferably movable between a transport position extending rearwardly beyond the main frame and a parked position in which the rear of the sub-frame is approximately coincident with the rear of the main frame.

The main frame and sub-frame may have side members with co-operating flanges whereby the relative movement of the frames is substantially restricted to movement in the fore-and-aft direction of the trailer which is limited by abutment stops. The side members of the frames preferably have apertures which register when the frames are in one of their limit stop positions whereby a locking pin can be passed through said apertures to lock the frames against relative movement.

The sub-frame may be a bogie having three pairs of road wheels mounted on respective springs.

If the main frame is adapted to support a container 6,096 mm in length with the rear end of the container substantially coincident with the rear end of the main frame the sub-frame, in the transport position thereof, preferably extends 990 mm beyond the rear end of the main frame.

Suitable flexible connections or "Suzies" are provided between the main frame and the bogie to provide pneumatic and electrical power respectively for the brakes and lights.

A preferred embodiment of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a side elevation of a trailer in accordance with the invention having its bogie in the extended or transport position, Figure 2 is a view similar to Figure 1, but showing the bogie in the retracted or parked position, Figure 3 is a plan view of the trailer with its bogie in the transport position, Figure 4 is a rear view, and Figure 5 is a detail on an enlarged scale taken on the line V-V of Figure 2.

The road semi-trailer illustrated comprises a main frame 10 designed to carry a container (not shown) 6,096 mm long with the doors at the rear end of the container substantially in the same vertical plane as a rear cross member 11 of the main frame. The main frame 10 also comprises a front cross member 12 which, together with the cross member 11, holds in spaced relation two "I" cross section longitudinal members 14.

Between these at the leading end of the trailer the usual provision is made at 1 5 for releasably articulating the trailer to the fifth wheel of a tractor vehicle (not shown) and telescopic land legs 1 6 braced by stays 1 7 extend from the members 14 to support the leading end of the trailer above the ground when the trailer is unhitched from a tractor vehicle.

The main frame 10 is 7,772 mm long but to support the container with its centre of gravity 4,038 mm from the rear end of the trailer it is necessary that the latter should extend 990 mm beyond the rear end of the container, the trailer having an overall length of 8,762 mm. To provide for this, in accordance with the present invention, the three pairs of road wheels 1 8 by which the rear of the trailer is supported are commonly mounted on a sub-frame 1 9 which is movable relative to the main frame 10 between limit stop positions shown respectively in Figure 1 and Figure 2.To permit relative sliding movement of the bogie comprising the sub-frame 1 9 and the wheels 1 8 in a horizontal plane, channel-section side members 20 of the sub-frame have inwardly directed flanges the upper ones 21 of which each have an underlying layer 22 of anti-friction material which rides on a bracket 23 fixed to the associated longitudinal member 14 of the main frame 10 so as to extend outwardly therefrom parallel with its foot 24. This, in turn, slidably rests on cross members 13 of the sub-frame 19 fixed in space relation to its side members 20, and at least the three sub-frame cross members 13 further from its rear end have guide blocks 26 positioned on their top surfaces to prevent relative lateral movement of the feet of the longitudinal members 14 of the main frame.In this way relative movement of the main frame 10 and the bogie 1 8, 1 9 is restricted in all directions except the horizontal fore-and-aft direction.

Rearward movement of the bogie 18, 19 relative to the main frame 10 is limited by stops 27' on top of the sub-frame side members 20 which abut stops 27" on the main frame 10 when the bogie is in the transport position shown in Figures 1 and 3, and forward movement of the bogie 18, 19 relative to the main frame 10 is limited by stops 28' on the main frame 10 which abut the leading cross member 13 of the sub-frame 19 when the bogie is in the parked position shown in Figure 2.

Beneath each joint between each cross member 13 and each side member 20 of the sub-frame 19 is welded a spring bracket 29. On the spring brackets 29 the suspensions (not shown) and the axles 25 of the three pairs of wheels 18 are mounted. Bolts 34, one of which is partially shown in Figure 5, are provided to lock the subframe 19 relative to the main frame 10 when in the transport position or the parked position. The bolts 34 travel in respective bosses 31 fixed to the longitudinal members 14 of the main frame in register with holes 32 therein. To lock the subframe 19 to the main frame 10 when in the position shown in Figures 1 and 3 or Figure 2 the bolts 34 are projected out of their bosses 31 so that they pass through holes 33 in the side members 20 and into bosses 30 integral with the latter.The bolts 34 may be in pairs which are oppositely displaceable transversely of the main frame by common pneumatic devices (not shown).

Flexible connections or "Suzies" (not shown) supply pneumatic and electrical power from the main frame 10 to the brake assemblies 35 and the electrical equipment 36 on the bogie 18, 19 and accommodate the relative movement of the bogie and the main frame.

When hitched to a tractor vehicle and travelling along a road the bogie is locked by the bolts 34 in the position shown in Figures 1 and 3. In this position a container 6,096 mm long mounted on the main frame so that the rear end of the container is upstanding from the rear end 11 of the main frame 10 will have its centre of gravity approximately 4,038 mm from the rear end 37 of the trailer, and the trailer will project 990 mm beyond the rear end of the container. When the trailer is stationary and it is desired to gain access to the doors in the rear wall of the container while the latter is still on the trailer the bolts 24 are caused to release the sub-frame 1 9 after which the main frame 10 and sub-frame 19 are relatively moved to the position shown in Figure 2. This can be effected quite easily by applying the brakes 35 of the trailer bogie and then moving the main frame 10 backward by reversing the tractor vehicle before unhitching the trailer. The main frame 10 is arrested in the position shown in Figure 2 by abutment of the stops 28' with the leading end of the bogie. It is locked in this position by the bolts 34. With the trailer in the parked position it may be unhitched from the tractor and supported at its forward end by the legs 16. It will be understood that while the trailer is stationary or parked it is not mandatory that the centre of gravity of the load should act 4,038 mm from the rear end of the trailer.

Claims (9)

1. A vehicle having a cargo-carrying main frame and a supporting wheel assembly the position of which relative to the main frame is adjustable longitudinally of the vehicle.

2. A vehicle as claimed in claim 1, wherein said wheel assembly is mounted on a sub-frame which has limited horizontal sliding movement relative to the main frame, means being provided to lock the sub-frame in at least one of its limit stop positions relative to the main frame.

3. A trailer vehicle as claimed in claim 1 or claim 2 having means at a forward position for articulated connection of the trailer to a tractor vehicle and a rear wheel assembly which is movable toward and away from said articulation means.

4. A trailer as claimed in claim 3 as appendant to claim 2, wherein the sub-frame is movable between a transport position extending rearwardly beyond the main frame and a parked position in which the rear of the sub-frame is approximately coincident with the rear of the main frame.

5. A trailer as claimed in claim 4, wherein the main frame and sub-frame have side members with co-operating flanges whereby relative movement of the frames is substantially restricted to movement in the fore-and-aft direction of the trailer which is limited by abutment stops.

6. A trailer as claimed in claim 5, wherein the side members of the frames have apertures which register when the frames are in one of their limit stop positions whereby a locking pin can be passed through said apertures to lock the frames against relative movement.

7. A trailer as claimed in any one of claims 46, wherein the sub-frame is a bogie having three pairs of road wheels mounted on respective springs.

8. A trailer as claimed in any one of claims 47, wherein the main frame is adapted to support a container 6,096 mm in length with the rear end of the container substantially coincident with the rear end of the main frame and wherein the subframe, in the transport position thereof, extends 990 mm beyond the rear end of the main frame.

9. A trailer substantially as described in the description with reference to and as shown in the accompanying drawings.