GB2078663A

GB2078663A - Loading and unloading platform for a road trailer

Info

Publication number: GB2078663A
Application number: GB8020685A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-06-24
Filing date: 1980-06-24
Publication date: 1982-01-13
Also published as: GB2078663B

Abstract

A "roll-loader" mobile crane can move under its own power backwards and forwards between a road trailer T and a fixed platform, with its wheels W running along rails R on the trailer and similar rails 10 on the platform. The rails 10 are supported by a carriage 11 so that they can move up and down in unison about a pivot shaft 27 and can tilt sideways about a pivot shaft 25, and the carriage 11 can in turn move horizontally sideways relative to a stationary plinth 12. When the road trailer T is reversed up to the platform, chamfered beams 29 attached to the rails 10 engage in chamfered recesses in an attachment 30 on the rear of the trailer and thereby causing the rails 10 to move about the pivot shafts 25, 27 and the carriage 11 to move along the plinth 12 as necessary to align the rails 10 with the rails R. <IMAGE>

Description

SPECIFICATION Loading and unloading platform for a road jailer This invention relates to a loading and Unloading platform for use in conjunction with a trailer of the type having guide means thereon on which a mobile crane or the like can run.

According to the present invention, such a platform comprises a fixed support, further guide means on which said mobile crane or the like can run, mounting means supporting the further guide means on the fixed support for horizontal and vertical movement relative thereto transversely of the direction of extent of the guide means, and alignment means movable with the further guide means and adapted for engagement with corresponding alignment means on said trailer, whereby during engagement of said trailer with the platform in use, the alignment means cause the further guide means to move relative to the fixed support as necessary to come into alignment with the guide means on said trailer.

Conveniently, the further guide means includes a pair of elongate guides or rails which are transversely spaced apart, and the mounting means also permits the further guide means to pivot about an axis which is parallel to said guides or rails; and which is preferabiy also substantially mid-way therebetween.

Vertical movement of the further guide means relative to the fixed support can be provided by a pivot which allows the further guide means to move angularly about a horizontal axis transverse to the direction of its extent, the pivot advantageously being disposed remotely from an end of the further guide means which is nearer said trailer in use.

Desirably, the mounting means includes a carriage on which the further guide means is carried and which is movable horizontally relative to the fixed support transversely of the direction of extent of the further guide means. The amount by which the carriage can move in this manner can be restricted, and means can be provided to limit the positions in which said trailer can be engaged with the platform, such as by blocks which are disposed so as to obstruct the trailer wheels if said trailer is positioned outside these limits.

The alignment means on the platform can comprise at least one projection, and the alignment means on said trailer can comprise at least one recess in which said at least one projection is engageable, the projection(s) and recess(es) having engagement surfaces which are chamfered in a horizontal plane and in a vertical plane.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in "'ihich:- Figure 1 is a front view of a platform according to the present invention; Figure 2 is a plan view of the platform shown in Figure 1; Figure 3 is a side view of the platform and also shows the rear end of a trailer partially engaged with the platform; Figure 4 is a rear end view of the trailer; and Figure 5 is a perspective view of the rear end of the trailer.

The illustrated platform is capable of supporting a mobile crane of the so-called "roll-loader" type which can move under its own power from the platform onto a road trailer (indicated at T in Figure 3) and from the trailer back to the platform as required. The mobile crane is not specifically shown in the drawings: however, its wheels are indicated at W in Figure 3. The crane is guided and supported in this movement by a pair of transversely spaced rails R on the trailer, and by a pair of correspondingly spaced rails 10 on the platform.It is a function of the platform to ensure that the two sets of rails are properly aiigned when the trailer is engaged with the platform, despite variation (within limits) in the height and attitude of the trailer due to its loading, and while allowing for variation (again within limits) of the lateral position of the trailer with respect to the platform.

To this end, the rails 10 are mounted on a carriage 11 for pivotal movement about two separate axes respectively parallel with and perpendicular to the direction of extent of the rails, and the carriage 11 is in turn supported on a plinth 1 2 for horizontal rectilinear movement relative thereto.

The construction of the platform will now be described in more detail. The plinth 12 includes two side frames each of which comprises a front leg 13, a rear leg 14 which is slightly longer than the front leg, and a horizontal beam 1 5 interconnecting the front and rear legs. A pair of horizontal I-section beams 1 6 interconnect the two side frames respectively adjacent the front and rear ends of the beams 1 5, their upper flanges forming guide rails along which flanged wheels 1 7 of the carriage 11 run. Inclined abutments 1 8 (see Figure 1) are provided at the ends of the beams 1 6 to limit the amount by which the carraige 11 can move along the latter.The two sides frames of the plinth 12 are also interconnected by a further I-section beam 1 9 which extends between the upper ends of the rear legs 14, the beam 1 9 being disposed with its web horizontal so that a front flange thereof forms a thrust-receiving surface along which a roller 20 (see Figure 3) on the carriage 11 can run. The structural components of the plinth 12 are all made of steel.

The carriage 11 comprises a chassis constructed from a pair of spaced, mutually parallel beam 21 of hollow rectangular cross section transversely interconnected by a further pair of spaced, parallel beams 22 which are disposed beneath the rails 10 respectively.

Outboard of the beams 22, a pair of axles 23 are rotatably journalled in sealed ball-bearing units mounted in the beams 21, the axles carrying a respective one of the flanged wheels 1 7 at each end thereof. Typically, the beams 21 and 22 have a cross-section of 1 52 mm x 102 mm, the axles 23 are of 50 mm diameter, and the diameter of the wheels 17 is 150 mm.

A pedestal 24 bridges the beams 22 slightly forward of the rearmost beam 21 and carries a shaft 25 on which a frame 26 is pivotally mounted by means of two sealed flanged bearings, the shaft 25 being disposed parallel to the rails 10 and mid-way therebetween, as viewed in plan. Sealed flanged ball-bearing units are carried by the frame 26 and pivotally support a shaft 27 which transversely interconnects the rails 10 at their rear ends. Pivotai movement of the shaft 27 relative to the frame 26 causes the front ends of the rails 10 to be raised and lowered in unison, while pivotal movement of the frame 26 with respect to the shaft 25 causes the relative heights of the rails 20 to be varied. The shafts 25 and 27 are positioned so that the movement of the rails 10 about the shafts presents a minimal charige at the platform/trailer rail junction.Typically the shafts 25 and 27 have a diameter of 70 mm.

The undersides of the forward ends of the rails 10 are interconnected by a transverse beam 28 from which two beams 29 extend forwardly in mutually parallel, spaced relation. The forward ends of these beams are chamfered inwardly to provide a lead-in to an attachment 30 (see Figures 3 to 5) which is secured to the rear ends of the trailer T. In a preferred arrangement, the beams 29 are constructed of 150 mm x 102 mm rectangular hollow section material and extend forwards for a distance of 500 mm, and their forward ends are chamfered at an included angle of 600 and are faced with 10 mm thick steel.

As can be seen to advantage in Figures 4 and 5, the attachment 30 includes a box-like structure 31 defining a recess whose side walls 32 are splayed outwardly in the rearward direction of the trailer so as to provide a lead-in for the forward ends of the beams 29 on the platform. It will be noted that the beams 29 and the side walls 32 are chamfered or splayed in both a horizontal plane and a vertical plane to assist proper engagement of the beams 29 in the attachment 30. When the beams are fully engaged in the attachment 30, the rails 10 on the platform are correctly aligned with the rails R on the trailer, and V-shaped tongues 31 on the forward ends of the rails 10 engage in correspondingly shaped notches 32 in the rear ends of the rails R.

In order to engage the trailer with the platform for loading or unloading, the trailer is reversed into a position in which the beams 29 enter the box like structure 31 of the trailer attachment. Upon further backing of the trailer, the chamfered surfaces of the beams 29 ride along the splayed walls 32 of the attachment 30, causing the rails 10 to pivot about the shafts 25, 27 and the carriage 11 to run along the plinth rails 16 as necessary until the beams 29 are fully engaged with the attachment 30, whereupon as described above the rails 10 on the platform become aligned with the rails R on the trailer. During this operation, the thrust imposed on the platform is received by the beam 1 9 via the roller 20.

Pivotai movement of the rails 10 about the shaft 25 compensates for a difference in the relative heights of the two trailer rails of up to 50 mm. Similarly, pivotal movement of the rails 10 about the shaft 27 compensates for variation in the height of the trailer rails above groundlevel, and up to 100 mm above and below a mean rail height can be accommodated in this manner. A trailer riding at a rail height of 1350 mm when engaged with the platform causes the rails 10 to tilt upwardly at an angle of 20 away from the trailer, while the trailer riding at 1450 mm will cause the rails 10 to tilt downwardly at an angle of 20 away from the trailer. When the trailer is disengaged from the platform, the rails 10 occupy a rest position in which they are inclined upwardly at 40.

Movement of the carriage 11 along the plinth rails 1 6 allows for variation in the position of the trailer in the transverse direction of the platform, so that the position in which the trailer is reversed up to the platform is not particularly critical. In fact, a misalignment of up to 125 mm on either side of centre can be accommodated in this manner. In order to ensure that the trailer cannot be reversed into a position outside these limits, blocks are preferably set into the ground forward of the platform so as to obstruct the wheels of the trailer if the latter is more than 125 mm off-centre: if the trailer is properly aligned with the platform then it will pass between these blocks.

When the trailer is fully engaged with the platform, it can be arranged that the trailer wheels rest against a second set of blocks set into the ground in order to prevent severe loads from being imposed on the platform. In addition, although not shown in the drawings, two braced steel posts can be positioned to either side of the plinth 12, carrying rubber pads which are level with the rear flush raves of the trailer.

Once installed, the platform described above is virtually maintenance-free particularly since all bearings thereof are sealed units. In the event of major attention being required, the platform can be dismantled into its various sub-assemblies, each of which is capable of being reduced to elementary components. Moreover, the attachment 30 is easily fitted to the trailer.

requiring only minor modification of the latter, and is capable of withstanding a considerable amount of use whilst being easily replaceable when worn.

Claims

1. A loading and unloading platform for use in connection with a trailer of the type having guide means thereon on which a mobile crane or the like can run, the platform comprising a fixed support, further guide means on which said mobile crane or the like can run, mounting means supporting the further guide means on the fixed support for horizontal and vertical movement relative thereto transversely of the direction of extent of the gtide means, and alignment means movable with the further guide means and adapted for engagement with corresponding alignment means on said trailer, whereby during engagement of said trailer with the platform in use, the alignment means causes the further guide means to move relative to the fixed support as necessary to come into alignment with the guide means on said trailer.

2. A platform as claimed in Claim 1, wherein the further guide means includes a pair of elongate guides or rails which are transversely spaced apart, and the mounting means also permits the further guide means to pivot about an axis which is parallel to said guides or rails.

3. A platform as claimed in Claim 2, wherein the axis about which the guide means pivots is disposed substantially mid-way between said guides or rails.

4. A platform as claimed in Claim 1, 2 or 3, wherein vertical movement of the further guide means relative to the fixed support is provided by a pivot which allows the further guide means to move angularly about a horizontal axis transverse to the direction of its extent.

5. A platform as claimed in Claim 4, wherein said pivot is disposed remotely from an end of the further guide means which is nearer said trailer in use.

6. A platform as claimed in any preceding claim wherein the mounting means includes a carriage on which the further guide means is carried and which is movable horizontally relative to the fixed support transversely of the direction of extent of the further guide means.

7. A platform as claimed in Claim 6, wherein the amount by which the carriage can move horizontally relative to the fixed support is restricted, and means is provided to limit the positions in which said trailer can be engaged with the platform.

8. A platform as claimed in any preceding claim, wherein the alignment means on the platform comprises at least one projection, and the alignment means on said trailer comprises at least one recess in which said at least one projection is engageable, the projection or projections and the recess or recesses having engagement surfaces which are chamfered in a horizonal plane and in a vertical plane.

9. A loading and unloading platform substantially as hereinbefore described with reference to the accompanying drawings.