GATHERING AND GUIDING ARRANGEMENT FOR THE LOADING AND UNLOADING OF CONTAINERS OR PLATFORMS ONTO VEHICLES

Abstract: A vehicle for carrying a container or platform has a lifting mechanism for loading the container or platform onto the vehicle. There are roller means (10, 12) rotatable about a substantially horizontal axis and located at the rear of the vehicle. A gathering and guiding means (16), preferably a rotatable roller, is located at each side of the vehicle forwardly of the roller means (10, 12) and positioned to be encountered by and to guide and centralise the container during a loading operation.

Description: This invention relates to a gathering and guiding arrangement for the loading and unloading of containers or platforms onto vehicles. It has been proposed, in French Patent Specification FR-A-2407095 published 1979, upon which the first part of claim 1 is based, to lift a container onto a vehicle using a chain or cable. At the rear of the vehicle are provided a rearmost pair of rollers (16 in the drawings of the French patent) and forward rollers 15 mounted in front of and slightly above the rollers 16. Some guidance is provided by plates 22. Both the rollers 15 and the rollers 16 rotate about horizontal axes. The purpose of the rollers 15 is to bear the weight of the container as it is being loaded. The rollers 15, being rotatable about a horizontal axis, would not in use effect any centralising function. It is customary, as shown for example in British Patent 2 033 346, Figure 1, see part 19, to provide rollers at the rear of a vehicle which is to carry a mountable and demountable container or platform which is to be loaded onto and unloaded from the vehicle by a pivotable hook arm. Often, in such a vehicle, to accommodate minor misalignment between the fore and aft axis of the vehicle and the fore and aft axis of the container, the rollers are shaped with inwardly sloping substantially frusto-conical outer ends. It has been found that under many conditions, e.g. darkness, poor visibility, uneven ground, sloping ground, and restricted area for manoeuvring the vehicle, that this arrangement is not adequate to cope with the minimum misalignment which the vehicle driver can reasonably achieve. It will be realised that the driver normally has only restricted vision in a rearward direction and that difficulties are particularly acute with long vehicles. In order to provide greater gathering capacity it is not practical to extend the frusto-conical outer end as the resultant increase in maximum diameter would foul the underside of the body members, and also increase the overall length of the chassis which could be undesirable. Also, the gathering characteristic of the frusto-conical member (roller) in such a known arrangement is such that there will be a point loading on the conical section at a position in the loading cycle when the rear end of the body is still on the ground. Thus the centralising or gathering function of the conical roller will be resisted by the ground contact of the body causing the still misaligned body to take up an attitude where there will be point loading at both sides of the vehicle. The above sequence will tend to distort the body members and will apply undesirable side loads to the lifting equipment. In practice the task of manoeuvring a vehicle into the proper position ready to pick up a container is often very time consuming, and to attempt a lift when the misalignment is too great may be very dangerous. It would be particularly dangerous if the vehicle was on a side slope as the lifting of a heavy or loaded container raises its centre of gravity several feet (metres) above the ground and the side force may tip the vehicle over sideways. It would be highly desirable if there was an effective mechanism so that a greater misalignment can be tolerated and safer operation achieved, than in prior art designs. US-A-3 225 945 directed to boat trailers shows guiding rollers whereby the axes of the guide rollers extend outwardly and forwardly. According to the invention there is provided the combination of a container or platform and a vehicle for carrying the container or the platform, the vehicle having a lifting mechanism for loading the container or platform onto the vehicle, said lifting mechanism including at least two relatively pivotable frames movable in a substantially vertical plane and driven by respective fluid-operable piston-cylinder devices, there being roller means rotatable about a substantially horizontal axis and located at the rear of the vehicle, and gathering and guiding means located at each side of the vehicle constituted by a rotatable roller, characterised in that the rotation axis of each of said rotatable rollers extends in a direction outwardly of the vehicle, upwardly and forwardly, in that each rotatable roller is located forwardly of the said roller means and is positioned to be encountered by the container or platform subsequently to it encountering the said roller means, whereby said rotatable rollers serve to guide and centralise the container or platform during a loading operation, and in that said gathering and guiding means is located so that it is encountered by a side edge of the container or platform shortly after the rear end of the container or platform has left the ground. In a particular embodiment of the invention, the rotation axis of each said rotatable roller may extend in a direction such that its projection onto a vertical transverse plane perpendicular to the vehicle fore and aft axis is a line between about 20 and 75, preferably between 25 and 50, degrees to the horizontal. The projection of the said rotation axis onto a vertical central plane of the vehicle may be a line between 20 and 75 degrees to the horizontal. In quoting these figures, and in the description herein, it is assumed that the vehicle is standing on a horizontal surface. The invention will be better understood from the following non-limiting description of an example thereof given with reference to the accompanying drawings in which:- Figure 1 is an end elevation, partly in section, looking rearwardly, showing one example of an arrangement in accordance with the invention; Figure 2 is a plan view of the left-hand side of the arrangement shown in Figure 1; and Figure 3 is a side elevation looking in the direction III indicated in Figure 1. The gathering and guiding arrangement illustrated in Figures 1-3 may be mounted at the rear of a vehicle for carrying a container. The vehicles shown in British Patent Specification Nos. 1 327 928, 1 371 811, 1416 864, 1 540 611 and 2 033 346 are examples of vehicles to which the present invention can be applied. The illustrated arrangement includes rear rollers 10, 12 mounted at the rear of the vehicle for free rotation about a common horizontal axis. Each roller is mounted in suitable bearings, the bearings being indicated at 14 in Figure 3. In contrast to the frusto-conical ended rollers conventionally used in prior art arrangements, the rollers 10 and 12 are both cylindrical, and have a greater axial extent, e.g. being 1½ times or twice as long as a conventional roller. A gathering and guiding means constituted in this embodiment of the invention by a roller 16 is provided at each side of the vehicle forwardly of the rollers 10, 12. Each roller 16 is mounted for free rotaiton on a shaft 20, there being suitable bearings internally of the roller to mount the roller on the shaft 20. The shafts 20 are both angled forwardly and upwardly so that the axes of rotation of the rollers 16 are disposed as described hereinabove. The vehicle chasis frame is indicated at 22. Each roller 16 is preferably substantially cylindrical in shape as illustrated. Alternatively, however, each roller 16 may be tapered, that is to say, may be shaped as a frustum of a cone with the larger diameter end outwardly of the vehicle. The rollers 16 are mounted in relation to the rollers 10, 12 and the path of travel of the lifting mechanism when loading a container onto the vehicle in such a manner that a misaligned container contacts one, then both of the rollers 10, 12 taking the vertical reaction resulting in rear of body leaving the ground. Following this the container makes contact with one of the rollers 16. The main weight of the container is then supported at two regions, i.e. by the hook (and the lifting mechanism to which it is attached) and the rollers 10, 12. As the lifting mechanism continues its travel in conventional manner the container continues to contact the gathering and guiding means and is thus centralised and guided to a proper position on the vehicle. In a container loading operation, the surface of the roller 16 first contacted by a side of a container underside longitudinal structural member is located a considerable distance laterally outwardly of the vehicle, and as a consequence the capability of the vehicle to safely load a container when the vehicle and container are misaligned is improved; in other words, an arrangement in accordance with the invention can cope more safely with a greater degree of misalignment than prior art arrangement. In a preferred embodiment of the invention, the lifting mechanism includes at least two relatively pivotably frames, movable in a substantially vertical plane, and driven by respective fluid-operable piston-cylinder devices. An example of this kind of arrangement is the vehicle disclosed and claimed in British Patent No. 2,033,346.

Claims: 1. The combination of a container or platform and a vehicle for carrying the container or the platform, the vehicle having a lifting mechanism for loading the container or platform onto the vehicle, said lifting mechanism including at least two relatively pivotable frames movable in a substantially vertical plane and driven by respective fluid-operable piston-cylinder devices, there being roller means (10, 12) rotatable about a substantially horizontal axis and located at the rear of the vehicle, and gathering and guiding means (16) located at each side of the vehicle constituted by a rotatable roller, characterised in that the rotation axis of each of said rotatable rollers (16) extends in a direction outwardly of the vehicle, upwardly and forwardly, in that each rotatable roller (16) is located forwardly of the said roller means (10, 12) and is positioned to be encountered by the container or platform subsequently to it encountering the said roller means (10, 12), whereby said rotatable rollers (16) serve to guide and centralise the container or platform during a loading operation, and in that said gathering and guiding means (16) is located so that it is encountered by a side edge of the container or platform shortly after the rear end of the container or platform has left the ground. 2. A combination according to claim 1 in which the said rotation axis extends in a direction such that its projection onto a vertical transverse plane perpendicular to the vehicle fore and aft axis is a line between about 20 and 75 degrees to the horizontal; and such that its projection onto a vertical central plane of the vehicle is a line between about 20 and 75 degrees to the horizontal. 3. A combination according to claim 2 in which the said projection onto the said vertical transverse plane is between 25 and 50°. 4. A combination according to claim 1, 2 or 3 in which the rotatable roller (16) is substantially cylindrical. 5. A combination according to claim 1, 2 or 3 in which the rotatable roller (16) is tapered, that is, is shaped as a frustum of a cone with the larger diameter end outwardly of the vehicle. 6. A combination according to any preceding claim in which each rotatable roller (16) has an axial length greater than its maximum diameter. 7. A combination according to any preceding claim in which bearings are located internally of each said rotatable roller (16) to mount each roller (16) on a respective shaft.

Inventors: RAISIO, REIJO JUHANI
Applicants: MULTILIFT LIMITED
Application year: 1985
Main classification: B60P1
IPC codes: B60P1