GB2105294A - Extensible and retractable gantry for mounting in a vehicle - Google Patents

Abstract

An extensible and retractable gantry can be mounted in or on a vehicle. The gantry comprises two frames (12, 13, 14) each mounted one behind another in the vehicle. Bracing beams (17) tie the two frames to one another. One of the frames stands adjacent the load- receiving entrance to the vehicle body. A beam (18) can travel along the top members (11) of the two frames within the vehicle body. The beam (18) supports a further beam (21) which is extensible and retractable out of and back into the vehicle body. When extended, the beam (21) projects out of the back of the vehicle, and a hoist (26) can travel towards the projecting end of the beam (21) to pick up a load initially standing on the ground adjacent the back of the vehicle and transfer it into the vehicle. The projecting end (28) of the beam (21) may be supported by a prop (28a) whilst the hoist (26) is being operated. When not in use, and with the beam (21) fully retracted, the travelling unit (18, 21) can be locked in a position adjacent one or other of the vehicle body sides and so interferes minimally with the loading area inside the vehicle body. <IMAGE>

Description

SPECIFICATION Extensible and retractable gantry for mounting in a vehicle The invention relates to an extensible and retractable gantry which, in use, can be mounted in or on the body of a vehicle and which carries, or is adapted to carry, a loadlifting mechanism which can be used to pick up loads from the ground on which the vehicle stands and transfer the loads into or onto the vehicle body.

The concept is particularly though not exclusively applicable to vehicles in the form of light delivery vans. Such vans usually have either a rear pair of double doors, or one or more side-mounted sliding doors, or both.

They may have to have relatively heavy pieces of equipment, such as welding sets, loaded into them. The load-receiving floor of the van is inevitably some distance above the ground on which the van stands, and it is often a strain for men to try to lift such heavy pieces of equipment off the ground and into the van.

Powered load-lifting mechanisms for use with light delivery vans are already known.

One example for use with a van having rearmounted double opening doors is shown in UK Patent Specification No. 1,475,324 (Ratcliff). A power-operated platform raises the load to the level of the vehicle floor, and when the load has been transferred into the vehicle, the platform and lifting slides can be folded into the vehicle to allow the double doors to be closed on them.

This illustrated mechanism works well, but it has two major drawbacks. It is extremely heavy and bulky, putting great strain on the vehicle's back axle; and, when folded into the vehicle behind the double doors, it takes up a great deal of the load-carrying space inside the vehicle. It is also relatively complicated, it has to be integrally installed and welded into the vehicle, causing much work, and although it raises the load to the level of the vehicle floor it does not positively transfer it into the vehicle from that level.

Another example, again patented by Ratcliff, is shown in UK Patent Specification No.

1,446,656. This is designed for use with vans having side-mounted sliding doors. Once again, it is a power-operated mechanism which lifts the load to the level of the vehicle floor but which does not positively transfer the load into the vehicle from that level. When not in use, it folds up and slides away be neath the vehicle floor. To that extent it is an improvement on the other Ratcliff mechanism briefly described overleaf, in that it does not take up space inside the vehicle. Again, how ever, it has to be specially fitted into the vehicle beneath the floor; it is very heavy and bulky, and puts strain on one side of the vehicle (the side on which it is mounted); and when not in use it occupies a relatively vulner able travelling position slung beneath the chassis of the vehicle.

The invention seeks to provide a lifting mechanism which can easily be mounted into and taken out of a vehicle, for example a light delivery van, and used to load the van from outside without being unduly heavy; without taking up an excessive amount of the loading space within the vehicle; and without the vehicle itself having to be extensively modified and specially adapted to take the lift.

The inventive concept envisages the use of a relatively simple yet robust gantry frame carrying an extensible and retractable beam, the beam travelling along the gantry between an in-use position, and an out-of use position in which it is well away from the main loading space, and the beam (or another part carried by the beam) being extensible and retractable so that, in use, it projects beyond the load receiving end of the vehicle body and is equipped with a lifting mechanism such as a hoist or a winch.

With such an arrangement in its in-use position, relatively heavy equipment can easily be hoisted to the level of the beam; the hoist, or the beam itself, can be retracted into the vehicle; the equipment released on to the vehicle floor; and the beam and hoist can then travel along the gantry, within the co nfines of the body, to a position in which they do not obstruct the loading area of the vehicle.

Specifically the invention provides an exten sible and retractable gantry for mounting in or on a vehicle, the gantry comprising two frames each themselves comprising an elon gate cross-beam spanning two spaced-apart uprights; means to mount the frames one behind the other in or on the body of a vehicle so that one of the frames stands over a load-receiving region of the vehicle body and its cross-beam is in parallel spaced-apart alignment with the cross-beam of the other frame; a further beam spanning the gap be tween the spaced-apart cross-beams and hav ing, at each of its opposite ends, respective means locating that end of the further beam on the adjacent cross-beam and enabling the further beam to travel along the cross-beam from one upright of the frame towards and away from the other upright; the further beam incorporating or carrying an extensible and retractable portion which, when retracted, lies substantially wholly within the gap between the spaced-apart cross-beams and which, when extended, projects at least partly beyond said one of the frames in a direction away from the other frame; and the extensible and retractable portion carrying, or being adapted to carry, a load-lifting mechanism.

Preferably a section of the extensible and retractable portion can, when said portion is I extended, be swung down to act as a prop between the projecting end of the portion and the ground on which the vehicle, carrying the gantry, stands. Loads lifted by the mechanism can then better be resisted by the projecting portion since it will no longer be simply an unsupported cantilever. The prop section may be adjustable in length to accommodate uneven ground or to accommodate situations such as, for example, when the vehicle backs up against a loading bay which is itself raised above the ground on which the vehicle stands.

Preferably also the load-lifting mechanism can travel back and forth along the extensible and retractable portion of the gantry, when that portion is extended, whilst said portion remains projecting beyond said one of the frames. If the projecting portion is supported by its prop section, the prop can remain in place whilst the load is being transferred. If the prop section is not in use, or is not present in a particular gantry, it is still easier to have to move only the load-lifting mechanism than to have to retract a multiple-part telescopic beam.

The load-lifting mechanism may be able to travel no farther than said one of the frames, bringing the load as far as but not fully into the load-receiving area of the vehicle. Preferably however the mechanism can travel back and forth into and out of the gap between the spaced-apart cross-beams (i.e. between the two spaced-apart gantry frames) whilst the extensible and retractable portion remains projecting beyond said one of the frames. The load can then be brought fully into the vehicle before being released on to the vehicle floor.

In the last-mentioned case, the extensible and retractable portion, when extended, must of course extend into the gap between the two frames as well as projecting in the opposite direction beyond said one of the frames.

As well as being mounted one behind the other in or on the vehicle, the frames may be tied to one another by bracing beams which span the gap between the frames and which extend, preferably, parallel with said further beam. These bracing beams increase the rigidity of the gantry as a whole. They also turn it into a self-contained structure which can readily be mounted on open-bodied forms of the vehicle as a single unit, rather than the two frames having to be mounted and aligned separately, and dismantled separately from the vehicle.

The bracking beams may be so positioned and constructed that said further beam, or a suitably lengthened or (more probably) shortened version thereof, can span the gap between the bracing beams and can travel along the bracing beams instead of travelling along the cross-beams. Thus the load-lifting part of the gantry could be made to project at will from the rear load-receiving region of the vehicle; from either side ioad-receiving region; or alternatively from both if a travelling beam of adjustable length was fitted. For example, the surface of the bracing beams along which the said further beam travels could be level with the corresponding beam-receiving surfaces of the cross-beams of the two frames.

Alternatively those surfaces ot the bracing beams could run above or below the corresponding surfaces of the cross-beams of the two frames, depending on the precise req.-ir- ments of side-loading as opposea to rearloading operation of the gantry. Whatever arrangement is used, the versatility of the basic inventive concept is apparent.

The invention includes within its scope a vehicle fitted with a gantry in accordance with the inventive concept. The vehicle may be a light delivery van but is not restricted to such vans. The gantry described and illustrated in this specification has been developed for use in an enclosed-bodied van, but the invention is equally applicable to open-bodied vehicles where the gantry can be mounted on the loadreceiving platform rather that inside a vehicle body.

One gantry embodying the invention, mounted in a vehicle in accordance with the inventive concept, is shown by way of example in the accompanying drawings. It will now be described with reference to those drawings, in which: Figure 1 shows the gantry and parts of the vehicle in perspective; Figures 2a and 2b show in detail the means which locate the opposite ends of the travelling beam on the cross-beams of the gantry frames; Figure 3 shows one end support of the extensible and retractable portion of the gantry; Figures 4a and 4b show the other end support of that portion; Figures 5a and 5b show the prop section of the projecting portion; and Figures 6a and 6b show the trolley which carries the load-lifting mechanism.

Figs. 5a and 5b are drawn to a scale larger than Fig. 1. All the remaining figures are drawn to a larger scale still. Fig. 1 does not show every detail of the gantry, or of the vehicle in which it is mounted, but it is intended to give an accurate overall impression of the way in which the gantry is constructed, mounted in the vehicle, and used.

The gantry is built around two frames each comprising an elongate cross-beam, referenced 11, spanning two spaced-apart uprights referenced respectively 12, 1 3. The components 11, 12, 1 3 are all box-section beams which are spot-welded to one another via angle plates referenced 14, 1 5. Steel plates 1 6 are welded to the bottom ends of each of the uprights 12, 1 3. Holes are trilled through each of these plates 1 6 to enable the two frames to be mounted one behind the other in the body of a vehicle indicated in chain line in Fig. 1 so that, as shown, one of the frames stands over the rear load-receiving region of the vehicle body; the other frame stands at the other end of the loading area of the body just behind the driver's cab; and the two frames, which are each essentially the same size and shape as one another, stand with their cross-beams 11 in parallel co-extensive spaced-apart relation.

The plates 1 6 of the frame adjacent the back of the driver's cab are bolted to the loadreceiving floor of the vehicle. The corresponding plates 1 6 of the other frame adjacent the rear load-receiving entrance of the vehicle are bolted through the floor to the chassis of the vehicle. Elongate bracing beams 1 7 run in parallel spaced-apart relation between the two frames 12, 13, 14 inside the vehicle body.

They are box-section beams, like the beams of the two frames. They extend at right angles to the cross-beams 11 and they effectively tie the two frames to one another. Each frame unit 11, 12, 1 3 can be welded up under precisely controlled conditions and can then be fitted into the van body and mounted therein as a single unit to which are affixed the remaining parts of the gantry which will be described shortly.

Short steel bracing straps tie the uprights 1 3 of one of the gantry frames (the one standing behing the driver's cab) to the vehicle body side pillars just behind the cab.

These strips are not shown in the drawings.

They help the gantry unit to stay rigidly located in the vehicle body. Apart from these strips, and the bolts which secure the plates 1 6 to the vehicle floor and vehicle chassis, the gantry frame relies on its own inherent rigidity to take the loads imposed on it. The vehicle body does not have to be specially cut, fitted, welded or otherwise adapted to take the gantry unit, and when the unit is removed the vehicle will be virtually unchanged from its original state and need not be refitted or repainted.

A further beam 1 8 spans the gap between the two spaced-apart gantry frames 12, 13, 14. It is a box-section steel beam, like the other beams of the gantry. To each of its opposite ends there is welded a respective roller-carrying trunnion 1 9. The rollers locate each end of the beam 1 8 on the top surface of the adjacent cross-beam 11, and enable the beam 1 8 to travel along the cross-beam from one upright 1 3 of the frame towards and away from the other upright 12, i.e. in Fig. 1 towards and away from each opposite side of the vehicle body and generally across the load-receiving area of the body.

Stops, not shown in the drawings, are positioned on the top surfaces of each upright 11 to prevent the rollers of the trunnions 1 9 from coming completely into contact with the side of the vehicle body. Other stops may be positioned just over half way along the length of each cross-beam 11, on the top surface thereof, so that the travel of the beam 1 8 across the body is effectively restricted to the position shown in Fig. 1 in which the beam is roughly half way across the gap between the bracing beams 1 7. Alternatively the beam 18 may be permitted to travel all the way across the vehicle body, from one upright 1 3 to the other upright 1 2 of each frame, in which case stops would be provided at each opposite end of each cross-beam 11 to prevent the rollers of the trunnions 1 9 from hitting either of the vehicle body sides.

The travelling beam 1 8 carries a further beam 21 which can be extended and retracted. When retracted, the beam 21 lies wholly within the gap, spanned by the beam 18, between the two gantry frames 12, 13, 14. When extended, the end of the beam 21 projects beyond the rear of the two gantry frames and out of the back of the vehicle. The vehicle is provided with the usual double opening rear doors, but these are not shown in Fig. 1. The beam 21 slides along the beam 1 8 and is supported thereon by respective front and rear roller trunnions 22, 23. The rollers of these trunnions engage the top surface of the beam 18. The beam 21 is a hollow box-section beam open at both ends.

Along the bottom face of the beam 21 there is spot-welded a steel flange 24. The flange projects, as Fig. 1 shows, from each side surface of the beam 21. A roller-carrying trolley 25 can travel back and forth along the flange 24. The trolley 25 carries a chain hoist, or winch, indicated generally by the reference 26. The hoist or winch is a loadlifting mechanism of Knows kind and need not be described in detail. It is preferably readily detachable from the trolley 25 with which it travels along the beam 21, 24.

A handle 27 hangs from the rear end of the beam 21. It enables the beam to be easily pulled out of, and pushed back into, the vehicle body by a man standing initially outside the vehicle. It is welded to the underneath of the flange 24.

A steel bar 28 is telescoped inside the hollow box beam 21. The bar is solid and rectangular in cross section. A section 28a, of this bar 28, can be swung down to act as a prop between the projecting end of the beam 21 and the ground on which the vehicle stands. At the very end of the section 28a is a foot 29.

Fig. 1 shows the gantry with the beam 1 8 locked in position half way across the vehicle body; the beam 21 and bar 28 extended to project out of the back of the vehicle; the prop 28a supporting the projecting end of the beam 21 and the bar 28; and the travelling hoist 26 being brought on its trolley 25 along the beam 21 and out of the back of the vehicle to be positioned over a load (not shown) which initially stands on the ground behind the vehicle. The load is lifted off the ground and suspended by the hoist 26. The trolley 25 is then pushed back along the beam 21, passed the frame 12, 13, 14 and beyond the trunnion 23 until the load is well inside the vehicle body.The load is then lowered on to the floor of the vehicle, the hook of the hoist 26 is released from it, and the hoist can be brought out again along the beam 21 to pick up and bring into the vehicle a further item of equipment.

When ali items of equipment have been lifted and loaded into the vehicle, or if only the one load is to be transferred, the prop 28a is swung back up in line with the rest of the bar 28; both bar sections 28, 28a are telescoped into the box beam 21; the beam 21 is slid back into the vehicle body along the beam 1 8 until the handle 27 is inside the gap between the two frames 12, 13, 14; and the double doors (not shown) can be closed.

The beam 21 can then be locked in its fully-retracted position, against the beam 18; and that beam 1 8 can be unlocked from its Fig. 1 position, pushed along the cross-beams 11 to a position in which it is adjacent one or the other of the vehicle body sides, and locked in that position in which it interferes minimally with the vehicle loading space.

Figs. 2a and 2b show in detail the construction of the roller trunnions 1 9 which locate and support each opposite end of the travelling beam 18. The rollers 31 themselves are made of hard nylon. They are secured rotatably to the single trunnion plate 32 by hardened steel pins 33. They are flanged, as shown in Fig. 2b, so as to embrace their adjacent cross-beam 11. The single trunnion plate is also flanged beneath, as Fig. 2b shows particularly clearly, at 34, the flange 34 running along but not normally contacting the underside of the cross-beam 11.

Steel plate webs 35 brace the trunnion plate 32 against the adjacent end face of the travelling beam 18. A rotatable locking knob 36 is carried in a co-operating threaded nut 37 welded to the outer face of the trunnion plate 32. The shank of the knob 36 passes through the plate 32 and bears in a slot machined in the adjacent face of the crossbeam 11 as Fig. 2b shows to locate the travelling beam 1 8 in position on the beam 11. Alternatively no slot could be machined in the beam 11 and the end of the knob 36 could simply bear frictionally against the adjacent surface of the beam 11 to lock the travelling beam 1 8 in any one of a number of desired positions along the length of the beam 11.

Figs. 3, and 4a and 4b, show respectively the construction of the roller trunnions 22 and 23 which support the projecting beam 21 beneath the travelling beam 1 8. Each of these roller trunnions comprises two spaced-apart trunnion plates with hardened nylon flanged rollers carried on pins between them. Each assembly 22, 23 has rollers which engage both above and beneath the beam 18. Both trunnions are welded via spaces 38 to the projecting box beam 21. The plates of the trunnion 23 are so welded along a greater length than those of the trunnion 22, since thay have to resist a greater force tending to separate the beam 21 from them.

Stops, not shown in any of the drawings, are mounted on the top surface of the beam 1 8 towards each opposite end of the beam.

They are engaged by the top rollers of the trunnions 22, 23 at each end of the travel of the beam 21 along the beam 18. They prevent the trunnions 22, 23 from hitting the trunnions 1 9 of the beam 18.

Fig. 5a shows how the prop 28a is pinjointed to the bar 28 so that it can be swung down to support the bar 28 when in its projecting position. The prop 28a is in three parts. One part is screw threaded and extends from the pin-joint 39. Another part is similarly screw threaded, but opposite-handed and is indicated by the reference numeral 41. It carries the foot 29. Each of these screw threaded parts enters one end of a hollow internally screw threaded tube 42 which occupies most of the length of the prop 28a. If the tube 42 is rotated in one direction, it advances towards the pin-joint 39 and it also draws the screw threaded part 41 towards the pin-joint. If the tube 42 is rotated in the opposite sense, it moves away from the pinjoint 39 and it also causes the screw threaded part 41 to extend out of the opposite end of the tube 42.

The foot 29 is simply pin-jointed to the end of the screw threaded part 41 as shown in Fig. 5b.

Pins 43 take up any slackness of fit between the bar 28 and beam 21. They could be eccentric, and so be adjustable to take up wear which might develop progressively between the two parts 28, 21. Further pins 44 engage a flange 45 welded to the inner end of the bar 28. They prevent the bar 28 from being pulled fully out of the box beam 21.

Although the bar 28 has been described as a solid rectangular section bar, it could be a hollow box beam. It could in fact be constituted by two box beams welded one on top of another. This would give a beam of extra strength for very little increase in weight. Any box beam would of course be lighter in weight than a solid bar, and in many cases would be better able to withstand the strains on it in this particular application.

Figs. 6a and 6b show the construction of the simple but robust trolley 25 which carries the hoist 26. Hardened nylon rollers are again supported between two spaced-apart trunnion plates which are held by threaded spacing pins. The rollers are flanged, but only on one face, as shown clearly in Fig. 6a. Accordingly the pins which secure the rollers to the trunnion plates are headed in similar manner to those securing the rollers to the single trunnion plate 32 of the trunnion assemblies 1 9 at each end of the travelling beam 1 8.

Although the frame units 11 , 1 2,1 3 have been described as welded-up units, they could instead be bolted together, using plates such as the plates 1 4 to provide the necessary ties between the uprights 12,13 and cross-beam 11.

Claims (9)

1. An extensible and retractable gantry for mounting in or on a vehicle, the gantry comprising two frames each themselves comprising an elongate cross-beam spanning two spaced-apart uprights; means to mount the frames one behind the other in or on the body of a vehicle so that one of the frames stands over a load-receiving region of the vehicle body and its cross-beam is in parallel spacedapart alignment with the cross-beam of the other frame; a further beam spanning the gap between the spaced-apart cross-beams and having, at each of its opposite ends, respective means locating that end of the further beam on the adjacent cross-beam and enabling the further beam to travel along the cross-beam from one upright of the frame towards and away from the other upright; the further beam incorporating or carrying an extensible and retractable portion which, when retracted, lies substantially wholly within the gap between the spaced-apart cross-beams and which, when extended, projects at least partly beyond said one of the frames in a direction away from the other frame; and the extensible and retractable portion carrying, or being adapted to carry, a load-lifting mechanism.

2. A gantry according to Claim 1 in which a section of the extensible and retractable portion can, when said portion is extended, be swung down to act as a prop between the projecting end of the portion and the ground on which the vehicle, carrying the gantry, stands.

3. A gantry according to Claim 1 or Claim 2 in which the load-lifting mechanism can travel back and forth along the extensible and retractable portion of the gantry, when that portion is extended, whilst said portion remains projecting beyond said one of the frames.

4. A gantry according to Claim 3 in which the load-lifting mechanism can travel back and forth into and out of the gap between the spaced-apart cross-beams whilst the extensible and retractable portion remains projecting beyond said one of the frames.

5. A gantry according to any of the preceding claims in which the frames are tied to one another by bracing beams which span the gap between the two frames and which extend, preferably, parallel with said further beam.

6. A gantry according to Claim 5 in which said further beam, or a suitably lengthened or (more usually) shortened version thereof, can span the gap between the bracing beams, and the opposite ends of the further beam can travel along the bracing beams instead of travelling along the cross-beams.

7. A gantry substantially as described herein with reference to, and as illustrated in, the accompanying drawings.

8. A vehicle incorporating a gantry according to any of the preceding claims.

9. A vehicle into which a gantry according to any of Claims 1-7 is incorporated in a manner substantially as described herein with reference to, and as illustrated in, the accompanying drawings.