NZ203397A - Retractable conveyor in floor of load-carrying deck - Google Patents

Description

Priority Date(s): , o r- 2 -23 Complete Specification Filed: • Class: &«?.?.'/?*. / . .£££1 ."#?■ ;Publication Data* fi.OJ P.O. Journal, No: M o. i v 25FEB1983 NEW ZEALAND The Patents Act, 1953 COMPLETE SPECIFICATION "IMPROVEMENTS RELATING TO LOAD HANDLING APPARATUS" WE, REXPORT INTERNATIONAL • {AUST.) PTY. LTD., a Company incorporated under the lavi/s of the State of Victoria, of 12-14 Tarnard Drive, Braeside, in the State of Victoria, Australia,.do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement.- 203397 "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 and yet is simple and effective in use on vehicles, or in warehouse floor installations .

In a broad form of the invention, there is provided a 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, the arrangement being such that said chain or cable means is retractably mounted in said slot to project f'V r \9 203397 — 3 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. Also the chain which may be of conventional closed linked type is 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 is provided.

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

The wear pad is 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 508,9 85.

The invention will be described in greater detail having reference to the accompanying drawings in which:- ♦' - ^ -1 ' • j ' " 19 AU6"i93£. 203 Figure 1 is a plan view schematically illustrating the conveyor device.

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

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

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 a substantially vertical axis in the floor of a container cargo hold or vehicle body or the like. The motors 18 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 the end of the chain run.

The chain 10 is preferably of the conventional closed link type 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. 203397 The housing 15 houses the operating conveyor chain which is exposed above floor level to move fehc a palletised load or container. The drive motors 18 and tensioning mechanism 30 e»4 the return feed chain is 5 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 cora-10 pressed air bag is preferred and pressure of approximately 100 kpa has been found to be adequate.

The arrangement is such that when the bag is inflated, the wear strip 16 is lifted with the chain to project above the level of the floor. See Figure 2. When 15 the bag is deflated, the wear pad 16 and chain fall^ below the level of the floor 13. The wear pad 16 is preferably of low friction high density plastics material having good resistance to wear.

The wear pad is preferably slotted into a base 20 material 19 which may be light metal, wood or a cheaper plastic? material.

The channel bracket 15 is prevented from spreading under load by a series of bolts 20 mounted in slots 21 to allow the reciprocal movement of these wear 25 pads and base 19. Preferably foam plastics 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 30 expose the run of chain above the floor level^ and engage a load mounted on the floor. The load is preferably mounted on a pallet for easy lifting and for mobility on the adjacent roller system 22. The motor 18 is started and the chain urges the load to move. Preferably the deck 35 includes roller conveyors 22 which may be of the type disclosed in Australian Patent No. 508,985 to reduce friction. 203397 With reference to Figures 5 to 7 the motors 18 are electric (a) and hydraulic (b)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 5 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 10 mounted in the floor of the container having spigots depending from driving sprockets 11 for interengaging with motors 18a and 18b.

The tensioning device 30 includes a pair of sprockets 33 mounted on a T-shaped pivot arm 34 pivotally 15 mounted about pivot point 35. The arm is spring tmocfc^ 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 20 drive sprocket wheel 11 substantially disposed with the spindle 51 in a horizontal plane. The drive motor(s) being mounted on a spring loaded pivoted plate for chain tensioning. The plate 52 is pivotally mounted on axle 53 such that the weight of the plate and its superstructure 25 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 electric motor 56 interconnected by a worm 57 and worm 30 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 35 17 is adjustable to suit varying loads. The engagement fv -3MAYN8S! a ♦ with the load may be segmental to move a load in one area of the deck independant of another area. This allows all gaps between pallet loads to be closed up or accumulated.

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 any forms including a projecting pawl to lock the load in either direction.

Other modifications may be made for example the drive sprockets 11 require notching to avoid slip however it has been found preferable 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 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. 203397 8

Claims (7)

WHAT WE CLAIM IS:

1. 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, the arrangement being such that said chain or cable 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.

2. Conveyor apparatus as claimed in claim 1 wherein the pulleys are rotatable about a substantially vertical axis.

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 paid 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 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/je^unloading section for interengagement with said conveyor means.

7. Conveyor apparatus substantially as herein described when having reference to the accompanying drawings. REXPORT INTERNATIONAL (AUST.) PTY.LTD