GB2152911A

GB2152911A - Container discharge apparatus

Info

Publication number: GB2152911A
Application number: GB08500812A
Authority: GB
Inventors: Douglas Charles Mcrae
Original assignee: National Research Development Corp UK
Current assignee: National Research Development Corp UK
Priority date: 1984-01-17
Filing date: 1985-01-14
Publication date: 1985-08-14
Also published as: GB8401111D0; GB2152911B; GB8500812D0

Abstract

A container discharge apparatus 19 provides a previously open-topped box 25 with a two-part lid 3,6. In operation, the apparatus is used to lift and invert the box 25 over a hopper (not shown) and the moving part 6 of the lid is withdrawn behind the fixed part 3 to provide an opening through which the contents of the box will discharge into the hopper. <IMAGE>

Description

SPECIFICATION Container discharge apparatus The present invention relates to container discharge apparatus and in particular, but not exclusively, to container discharge apparatus for tipping a box or other container to discharge therefrom potatoes or other agricultural produce contained therein.

Many thousands of tonnes of potatoes in the United Kingdom are stored each year in boxes with a capacity of 1 tonne. Other capacities are 0.5 tonne and 2 tonnes. These boxes are emptied each year by placing them in a static box tipper mounted often over a storage hopper, or by a tipper unit mounted on a fork lift truck, either of the industrial or the rough terrain type.

Present day box tippers, whilst they succeed in completely emptying the box, allow the potatoes to escape in a relatively uncontrolled manner. As the potatoes exit from the box, they may impact against the top clamp of the box and often pour over the sharp edge of the angle iron clamping plate usually fitted to retain the box in position as it tips.

The mode of tipping of the box may be by a forward movement or a lateral movement about the centre of the long axis of the box. in both cases, potatoes (or other produce) furthest from the front edge of the box avalanche rapidly out, combining their journey to the escape point with the drop thereafter. This can be damaging and it is an object of the present invention to provide a container discharge apparatus in which this drawback is eliminated or at least significantly reduced.

According to the present invention, a container discharge apparatus comprises means for attaching the apparatus to an at least partially opentopped box or like container, closure means for at least partially closing the previously open-topped region of the container, and control means operative to effect withdrawal of the closure means from the previously open-topped region of the container whereby after use of the tipping means to lift and tip the container so as to bring the contents of the container into contact with the closure means, said withdrawal of the closure means by the control means allows at least some of the contents of the container to escape through said now open region of the container.

Conveniently, the closure means comprises a sliding lid member and the control means is operative to slide the lid member laterally between its open and closed positions.

The invention also includes an assembly comprising the container discharge apparatus of the present invention in combination with the tipping means for lifting and tipping the container so as to bring the contents of the container into contact with the closure means.

Conveniently, the tipping means is operable to tip the container through an angle in excess of 90 and preferably in excess of 130 .

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of a container discharge apparatus set up ready for use; Figures 2a and 2b show a first operational mode of the apparatus of Figure 1; and Figures 3a and 3b show a second operational mode of the same apparatus.

Thus referring first to Figure 1, a container discharge apparatus 19 in accordance with the present invention is shown mounted on a conventional tipper unit 20 mounted on a fork lift truck 21 of which only the two lifting forks 22, 23 are visible in Figures 1, 3a, and 3b of the drawings.

The container discharge apparatus 19 comprises a rectangular steel frame 24 comprising two channel section steel members 1 attached to a cross beam 11 and a box retaining flange 2 and a rear angle iron member (not shown). A fixed lid 3 occupying approximately half the width of the attachment and spanning the two members 1 lends rigidity to the structure and retains the potatoes in co-operation with a sliding lid 6. The fixed lid carries two slide rails 5.

The sliding lid 6 which is provided with a round front edge 7 slides in the channels on rails 8. The underside of the lid carries two countersunk slide rails which slide on top of slide rails 5. The four corners of the lid (not shown) carry small nylon rollers to prevent jamming of the lid should it skew slightly. A ram clevis 9 is attached near the leading edge of the lid on top of twin thrust roller rails 10.

The cross beam 11 is drilled to carry a double acting ram 12 and plated to restore its strength in the region of the ram hole drilling. The ram is mounted on trunnion plates 13 and is free to pivot through a limited angle in a vertical plane. The plates 13 carry two ball races which act as thrust rollers 14 running on the thrust roller rails 10.

The frame 24 is connected to the clamping bar 15 by a clamping bar clevis 16. The clevis may be fitted with stops so that the attachment adopts a substantially horizontal rest position.

In operation, a box 25 filled with potatoes or other produce, is lifted by the fork lift tipper unit 20 in the normal way after the clamping bar ram 17 has lowered the attachment on to the box.

The operator now raises the box on the forks, places it over the hopper or container into which the potatoes are to be tipped, inverts it and presses a hydraulic control lever (not shown) to retract the lid. The lid, as it moves back slowly, releases the load. The controlled drop and the ability to move the box to a lower position in the hopper minimise damage. Tests using the attachment have shown a reduction of 75% in splitting of the potatoes compared with conventional tippers.

For safety reasons it is desirable that the hydraulic system operating the lid operates in a set sequence so that the lid is closed whilst the box is still over the hopper and before it is tipped back to the horizontal position. This arrangement will reduce the risk of accidental trapping of hand or limb between the lid and the box retaining flange and cross bar. If desired, as an added safety feature, a 25 mm thick stop 18 may be fitted to prevent the lid from fully closing.

Although the apparatus 19 is intended for use with box tippers of either the forward tipping or side tipping form, only the forward tipping mode of operation has been described above. In fact, the basic principle is the same whatever the mode of tipping. However, the attachment for side tipping would be modified slightly to take account of the direction of movement of the potatoes by having the lid retract along the long dimension of the box 25 i.e. at right angles to that shown in Figure 1.

Figures 2a and 2b and Figures 3a and 3b have been included to illustrate forward and side tipping of the container 25. For clarity, these Figures are diagrammatic only and the container discharge apparatus has in fact been entirely omitted from Figures 3a and 3b where reference numeral 26 indicates a side retaining arm of the tipper unit.

This is engaged by the right-hand side of the box 25 (as in Figure 3a) at least during the clockwise rotation of the box towards the position shown in Figure 3b.

Regarding the construction of apparatus 19, it should be pointed out that because a full tonne load is imposed on the lid 6 after inversions of the box 25, it is desirable to support it against deflection though not absolutely essential. The characteristics of 25 mm thick plywood (exterior grade) make for a good lid material. The thrust of the weight prior to opening the lid 6 when the box is upside down creates a maximum bending movement in the centre of the lid and this is transmitted to the thrust rollers from the thrust roller rails. The fixed lid 3 also deflects and it transmits thrust to the rollers through the fixed lid slide rails and the corresponding slide rails on the retractable lid.

Although there is no currently enforced standard size for 1 tonne boxes for which the device is principally (but not exclusively) designed, attachments could of course be produced to suit whatever sizes predominate.

The use of the attachment on a fork lift with side shift is beneficial for making the operation easier.

Claims

1. For use with a tipper unit, a container discharge apparatus comprising means for attaching the apparatus to an at least partially open-topped box or like container, closure means for at least partially closing the previously open-topped region of the container, and control means operative to effect withdrawal of the closure means from the previously open-topped region of the container whereby after use of the tipping means to lift and tip the container so as to bring the contents of the container into contact with the closure means, said withdrawal of the closure means by the control means allows at least some of the contents of the container to escape through said now open region of the container,

2.An apparatus as claimed in Claim 1 in which the closure means comprises a sliding lid member and the control means is operative to slide the lid member laterally between its open and closed positions.

3. An assembly comprising a container discharge apparatus as claimed in Claim 1 or Claim 2 in combination with the tipping means for lifting and tipping the container so as to bring the contents of the container into contact with the closure means.

4. An assembly as claimed in Claim 3 in which the tipping means is operable to tip the container through an angle in excess of 90".

5. An assembly as claimed in Claim 4 in which the tipping means is operable to tip the container through an angle in excess of 130 .

6. An apparatus or assembly substantially as hereinbefore described with reference to, and/or as illustrated in, Figures 1, 2a, and 2b of the accompanying drawings.

7. An apparatus or assembly substantially as hereinbefore described with reference to and/or as illustrated in, Figures 1, 3a and 3b of the accompanying drawings.