GB2118518A - Improvements relating to load-handling apparatus - Google Patents

Abstract

Conveying apparatus for incorporation in a floor (13) to move a load therealong, the floor having an elongate slot therein. The conveying apparatus comprises an endless cable or chain (10) mounted on an arrangement of drive (11) and guide (12) pulleys rotatable about generally parallel axes so that the chain or cable travels along said slot in the floor. Elevating means (e.g. an inflatable pad) is arranged to raise and lower the path of the cable or chain in the slot relative to the floor, so that when raised the chain or cable will be above the level of the floor to engage a load on the floor and move the load along the floor. <IMAGE>

Description

SPECIFICATION Improvements relating to load handling apparatus The present invention relates to load handling apparatus particularly conveying apparatus suitable for mounting on a body of a transport vehicle or container.

A number of so-called movable floor systems are available in which chain conveyors are mounted for engaging and moving loads into position for carriage or storage. Such systems known to applicant involve the use of heavy and large power drives and require large spatial zones to accommodate them.

Roller conveyors have been disclosed in patent literature comprising a series of rollers and driven in a common direction to advance a load placed thereon. Such arrangements include a rope frictionally engaging and driving the rollers from beneath.

Examples of this type of conveyor are disclosed in U.S. patent Nos. 2,002,830; 2,129,510; 1,959,157 and 3,610,406. One disadvantage with these constructions is the large amount of space utilised. In some truck, warehouse and container applications, space is at a premium. It is also desirable in applications of the invention to provide for continuous handling of loads from truck to warehouse or load utilisation centres resulting in desirable reduction of storage spaces.

The present invention seeks to provide a conveying device of relatively small dimension which is simple and effective in use on vehicles, or in warehouse floor installations.

!r. a broad form of the invention, there is provided G corlveyor apparatus for a load on a load carrying deck including endless powered conveyor means extending along the deck for conveying the load along the deck, said conveyor means being retractable to be moved between a projected load engaging position and a non engaging position.

There is provided according to the present invention conveyor apparatus for mounting in the floor of a storage container or transport vehicle including a slotted floor, an endless chain or cable means mounted in the slot, for engaging and conveying a load along the floor in the direction of said slot, said chain or cable being mounted on driving and/or guiding pulleys rotatable about a substantially vertical axis the arrangement being such that said chain means is retractably mounted in said slot to project above the plane of said floor in use to frictionally engage a load for movement thereof.

Conveniently, the chain means is reversible and frictionally engages said load to allow limited slip.

The chain, which may be of conventional closed linked type, can be mounted on a wear pad which is vertically reciprocable to project or retract said chain in the plane of the floor. To ensure constant engagement on the sprocket or pulleys, a chain tension compensator means may be provided.

In one form of the invention, a wear pad is mounted upon a pneumatic or hydraulic elevating means. Alternatively, the wear pad may be mechanically moved by cams, wedges or the like.

The wear pad can be slotted to accommodate the specific profile of the chain used to ensure smooth and aligned movement of the chain along the wear pad.

In an alternative form of the invention the conveyor apparatus may be mounted in the floor of a shipping container with standard hydraulic and/or electric drive means provided in a truck chassis, ship hold or storage area wherein the container may be mounted.

Preferably the chain conveyor of the present invention is used in association with a floor including a roller track system which allows relatively free movement of the load on rollers which themselves may be retractable (such as disclosed in Australian Patent No. 508,985).

The invention will be described in greater detail having reference to the accompanying drawings in which Figure 1 is a plan view schematically illustrating the conveyor device.

Figure 2 is a partial sectional end view showing a wear pad and support in a chain housing.

Figure 3 is a partial side view taken on line A-A in Figure 2.

Figure 4 is an end view of an electric motor drive.

Figure 5 is a partial perspective view of a container mounted conveyor apparatus.

Figure 6 is a partial detailed view of part A of Figure 5.

Figure 7 is a partial perspective view of a tray mounted conveyor apparatus.

Figures 8 and 9 show views of an alternative drive mechanism.

Referring to Figure 1, the conveyor includes an endless chain 10 engaging around sprockets 12 mounted for rotation about substantially vertical axes in the floor 13 of a container cargo hold or vehicle body or the like. Motors (18a, 18b) are preferably mounted in a central location and may be electric, hydraulic or pneumatic. A tensioning device 30 is provided to absorb slack and maintain a substantially constant tension in the endless chain 10. The motors may be mounted at one end of the chain run.

The chain 10 is preferably of the conventional closed linktype made of strong, hard wearing and relatively inexpensive material. The deck or floor 13 is slotted to expose the chain along the majority of one side of the chain length, with the chain then receding beneath the floor to engage the end sprockets 12 and the motor drive mechanism. The axes of the sprockets may be inclined slightly to the vertical to ensure smooth meshing of the chain and each sprocket.

Referring to Figures 2 and 3 the slotted deck includes a chain housing 15 accommodating a slotted wear pad 16 and a lifting bag 17.

The housing 15 houses the operating conveyor chain which is exposed above floor level to move the palletised load or container. The drive motors 18(a, b), tensioning mechanism 30 and the return feed chain are housed under the floor surface. Preferably the bag is filled with compressed air, however, it will be appreciated the device may be hydraulic or mechanically actuated by cams, wedges or linkages preferably in segmental sections along the full length of the deck. Use of a compressed air bag is preferred and a pressure of approximately 100 kpa has been found to be adequate.

The arrangement is such that when the bag is inflated, the wear pad 16 is lifted with the chain to project above the level of the floor. See Figure 2.

When the bag is deflated, the wear pad 16 and chain falls below the level of the floor 13. The wear pad 16 is preferably of low friction high density plastic material having good resistance to wear.

The wear pad is preferably slotted into a base material 19 which may be light metal, wood or a cheaper plastic material.

The channel bracket housing 15 is prevented from spreading under load by a series of bolts 20 mounted in slots 21 to allow the reciprical movement of these wear pads and base 19. Preferably foam plastic or soft rubber gasket material 31 is inserted in a continuous inset 32 formed in the side of base 19. This restricts entry of sharp objects into the area near the inflated bag.

In operation the wear pad 16 is lifted up to expose the run of chain above the floor levels and engage a load mounted on the floor. The load is preferably mounted on a pallet for easy lifting and for mobility on an adjacent roller system 22. The motor 18 is started and the chain urges the load'to move.

Preferably the deck includes roller conveyors 22 which may be of the type disclosed in Australian Patent No. 508,985 to reduce friction. The roller conveyor can be of the retractable type.

With reference to Figures 5 to 7 motor 1 8a is electricand motor 18b hydraulic and either can be the motive force depending upon whether there is a source of electrical or hydraulic power available on the truck or on site.

The arrangement illustrated in Figure 5 depicts a freight container mounted conveyor apparatus adapted to be interengaged onto a base such as a truck tray or an unloading or loading bay. The conveyor apparatus is mounted in the floor of the container having spigots 11 a depending from the driving sprockets 11 for interengaging with slotted drive heads of the motors 1 8a and 1 8b.

The tensioning device 30 includes a pair of sprockets 33 mounted on a T-shaped pivot arm 34 pivotally mounted about pivot point 35. The arm is spring biased at 36 to maintain substantially constant tension.

Referring to Figures 8 and 9 an alternative drive is illustrated. The motor drive mechanism may be contained in a unitised housing with guide pulleys 50 and drive sprocket wheel 11 substantially disposed with its spindle 51 in a horizontal plane. The drive motor(s) is/are mounted on a spring loaded pivoted plate for chain tensioning. The plate (52) is pivotally mounted on an axle 53 such that the weight of the plate and its superstructure tends to tension the chain 10. In addition an adjustable spring mounted tensioning device 54 maintains stability of the arrangement under operating conditions.

The drive includes a hydraulic motor 55 and an electric motor 56 interconnected by a worm 57 and worm wheel 58 drive. The sprocket 11 is supported in bearing 59. The spring tensioning device includes adjustment means 60 to allow adjustment of tension and to allow up and down movement of the plate during operation.

The degree of upward pressure exerted by the bag 17 is adjustable to suit varying loads. The engagement with the load may be segmental to move a load in one area of the deck independent of another area.

This allows gaps between pallet loads to be closed up.

The optional horizontal disposition of the sprocket drive allows for relatively low head room as is available within the structure supporting standard transport decking. Thus the chain mounting guides and end pulley or sprocket system can be accommodated in a height of only 75 mm between chassis members and the deck surface.

Low kerbs may be provided on each side of each load track to ensure straight tracking of the load.

Usually two load tracks are fitted with a vehicle deck width limit.

Safety lock out means can be added to prevent uncontrolled movement of the load on the load carrying deck. The lock out means may take many forms including a projecting pawl to lock the load in either direction.

Other modifications may be made. For example the drive sprockets 11 may be notched to avoid slip, however it has been found preferably not to notch other sprockets in the conveyor system to avoid local tightening of the chain. Referring to Figure 6 a chain support roller 40 is provided at the loading and unloading end of the conveyor to take the high loads that may occur as the load first meets, or moves off, the chain. The roller 40 ensures that the chain engagement of the load is retained for the full extent of the conveyor length. The position of the roller is adjustable by a bolt adjustment 41.

To avoid overloading or equipment damage either or both the hydraulic and electric motors 18 may be fitted with a clutch (not shown) to allow disconnection of one unit when the other is providing power particularly in the case of one unit driving through an irreversible gear or worm and worm wheel drive.

Claims (8)

1. A conveyor apparatus for a load on a load carrying deck including endless powered conveyor means extending along the deck for conveying the load along the deck, said conveyor means being retractable to be moved between a projected load engaging position and a non engaging position.

2. Conveyor apparatus for mounting in the floor of a storage container or transport vehicle including a slotted floor, an endless chain or cable means mounted in the slot, for engaging and conveying a load along the floor in the direction of said slot, said chain or cable being mounted on driving and/or guiding pulleys rotatable about a substantially vertical axis the arrangement being such that said chain means is retractably mounted in said slot to project above the plane of said floor in use to frictionally engage a load for movement thereof.

3. Conveyor apparatus as claimed in claim 1 or 2 wherein the endless conveyor means is a chain of conventional closed link type and is mounted on a slotted wear pad vertically reciprocable to move the chain between said retracted and projected position.

4. Conveyor apparatus as claimed in claim 3 wherein the wear pad is mounted upon an inflatable bag.

5. Conveyor apparatus as claimed in any preceding claim when used in conjunction with a roller track system or conveyor.

6. Conveyor apparatus as claimed in claim 5 wherein the roller conveyor is of the retractable type.

7. Conveyor apparatus as claimed in any preceding claim wherein the conveyor means is mounted in the floor of a freight container or transport vehicle and the driving means is mounted separately onto a transport chassis or loading and unloading section for interengagement with said conveyor means.

8. Conveyor apparatus substantially as herein described when having reference to the accompanying drawings.