Technical Field

The present invention relates to an improved top hatch design for a bulk container. As used herein, the term "bulk container" means a shipping container suitable for transporting particulate bulk materials, (e.g. grain) by sea, rail or road.

Background Art

Any discussion of the prior art throughout the specification is not an admission that such prior art is widely known or forms part of the common general knowledge in the field.

In the past, bulk materials commonly have been transported in hoppers (by rail) or trailers (by road). In general, the hoppers or trailers have been open topped or covered by flexible canvas covers. The use of bulk containers for bulk materials has become increasingly popular, especially where the bulk materials need to be kept clean, dry, and free from any contamination. Further, bulk containers are advantageous if a particular load needs to be kept separate and identifiable for the whole of its journey:- for example, there is an increasing demand for wholly traceable food stuffs which can be guaranteed to be (for example) "organic" or free from genetically engineered material.

Bulk containers commonly in use at present are filled through an opening in the top of the container; this opening is covered either by a canvas cover or by a porthole type of cover. The canvas cover has the drawback of having a relatively short working life, and is unlikely to be reliably waterproof. The porthole type of cover can be made completely waterproof, but has to be opened and closed by somebody climbing on to the top of the container, releasing the catch, and swinging the cover open; this is a time-consuming job, and can be dangerous. Disclosure of Invention

An object of the present invention is the provision of a top hatch for a bulk container which ameliorates at least some of the above described problems.

The present invention provides A top hatch for a bulk container which includes a hatch cover which is arranged to slide between an open position to allow access to an aperture in the top of a bulk container, and a closed position to close said upper aperture in the bulk container; wherein the sliding movement between open and closed positions is controlled by a control means adapted to be mounted on the side of the container.

Preferably, the hatch cover extends over a major portion of the length of the bulk container.

Preferably, the sliding movement of the hatch cover between open and closed position is achieved by cables connected between the hatch cover and the control means.

Preferably, said cables are arranged such that the movement of the hatch cover between the open and closed positions is achieved by pulling one or more of the cables.

Preferably, said control means includes a lever adapted to be pivotally mounted on the side of the container, said cables being connected to said lever such that movement of said lever pulls said cables.

In a first embodiment of the invention, said lever is adapted to be pivotally mounted on the side of the container at the upper end of the lever and said cables are connected to the lower end of said lever. The hatch cover is movable from the open to the closed position by means of a first pair of cables, each of which is secured at one end to one side of the hatch cover and at the other end to the lower end of said lever; and the hatch cover is movable from the closed to the open position by means of a second pair of cables, each of which is secured at one end to the opposite side of the hatch cover and at the other end to the lower end of said lever. In a second embodiment of the invention, said lever is adapted to be pivotally mounted on the side of the container at a point intermediate the ends of the lever; said cables are connected to the upper end of said lever, adjacent the top of the container; and the lower end of said lever is arranged to be moved from side to side about said pivot, to move the hatch cover between open and closed positions. The hatch cover is movable between the open and closed positions by two cables, one of which is secured to one side of the hatch cover and the other of which is secured to the other side of the hatch cover. Preferably, said one cable is secured, at one end to one side of the upper end of said lever, is secured to said one side of the hatch cover, extends around the top of the container, and the other end of said one cable is secured to the opposite side of the other end of said lever; and said other cable is secured at one end to said one side of the upper end of said lever, extends around a first turning point located between said one side of the upper end of said lever and said one side of the hatch cover, is secured to the other side of said hatch cover, extends around a second turning point located adjacent said other side of said hatch cover, and is secured at the other end to said other side of the upper end of said lever.

Preferably, the lower end of said lever is mounted for horizontal movement along a guide bar.

Preferably also, the hatch cover is supported such that its upper surface is inclined: - this assists in shedding moisture. The hatch cover may be slidably supported upon a pair of inclined bars adapted to be mounted on the top of the container, one on each side of said aperture. Preferably, a coving is arranged cover the higher end of said inclined hatch cover when the hatch cover is in the closed position.

The present invention also provides a bulk container incorporating a top hatch as disclosed above. Preferably, the aperture in the top of the bulk container extends over a major portion of the length of the top of the bulk container.

Brief Description of the Drawings

By way of example only, a preferred embodiment of the invention is described with reference to the accompanying drawings in which :- Figure 1 is isometric view of a container incorporating a top hatch in accordance with the present invention;

Figure 2 is an isometric view of part of the container of Figure 1 , on a larger scale and showing the hatch open;

Figure 3 is an end view of part of the container;

Figure 4 and 5 are plan views of the top of the container, showing the cables;

Figure 6 is a side view of the container;

Figure 7 is a view of part of Figure 6, on a larger scale;

Figure 8 is a side view of the container incorporating a second embodiment of the present invention; and

Figure 9 is a plan view of the top of the container of Figure 8, showing the cables.

Detailed description of one example embodiment of the invention

Referring to the drawings, a bulk container 10 is formed from two longer sides 1 1 , two shorter sides 12, a base 13 and a top 14; the sides, base and top all are formed from ribbed or otherwise reinforced sheet metal that is welded together in known manner. The container may be of conventional construction or, preferably, is of the improved construction described in the co-pending application of the same date.

The top 14 is formed with a filling aperture 15 which extends nearly the full length of the top, parallel to the longer sides 1 1 , and is rectangular in plan. Each of the shorter sides of the aperture is fitted with a wedge shaped support 17, which increases in height across the length of each side; the lower end of each support 17 is flat with the top 14.

A coving 18 extends along the longer side 19 of the aperture 15 which is adjacent the higher ends of the supports 17.

A hatch cover 20, which is slightly larger in plan than the filling aperture 15, is arranged to slide over the aperture 15, to close the aperture. The hatch cover 20 is a flat panel, each shorter end of which is mounted on spaced brackets 21 , and arranged to slide on bars 22 which are secured in mountings 23, 23a, along both of the shorter sides of the aperture 15. Each bracket 21 is apertured to be a sliding fit on the corresponding bars 22 and either is made of a bearing material or is fitted with a suitable bearing so that it slides smoothly on the bar 22.

Each mounting 23a adjacent the coving 18 is higher than the corresponding mounting 23, so that each bar 22 slopes at the same angle as the supports 17. The height of the coving 18 is such that the return edge 18 a of the coving lies above the ends of the supports 17, and is spaced above those supports by a sufficient distance to allow the cover 20 to pass underneath. This provides a waterproof cover for the container when the cover 20 is in the closed position and the upper edge of the cover 20 lies underneath the edge 18 a of the coving 18. The fact that the bars 22, and hence the cover 20, are inclined, assists the cover to shed water readily and prevents water from pooling on the cover.

As shown in Figures 4 - 7, the hatch cover 20 is slid between the open and closed positions by means of cables (shown in broken lines) which pull the cover to the desired position. Cables 30, 31 for moving the hatch cover 22 to the open position are secured one to each side of the leading edge 32 of the hatch cover 20. The leading edge 32 of the hatch cover is the edge which, when the hatch cover is closed, lies beneath the coving 18.

As shown in Figures 4 and 6, the cable 30 is secured to one side of the leading edge 32, extends down that side of the hatch cover and across the top 14 of the container to the adjacent longer side 1 1 , along edge of the joint between the top 14 and the corresponding longer side 1 1 , down the edge of the longer side 1 1 and along the lower margin of that side, to be secured to the control lever 35.

The cable 31 is secured to the other side of the leading edge 32, extends down the corresponding side of the hatch, and across the top 14, and then extends parallel to the cable 30 down the edge of the longer side and along the lower margin of that side, and is also secured to the control lever 35. As shown in Figures 5 and 6, cables 36, 37 for moving the hatch cover to the closed position are secured one to each side of the trailing edge 38 of the hatch cover. The trailing edge 38 of the hatch cover is the edge which is lower when the hatch is in the closed position shown in Figure 3.

The cable 36 is secured to one side of the trailing edge 38 of the hatch cover 20, extends along the side of the hatch cover and along the top of the container, and then along the adjacent longer edge of the top 14, and down the adjacent edge of the side 1 1 of the container, and along the lower margin of that side, to be secured to the control lever 35.

The cable 37 is secured to the other side of the trailing edge 38 of the hatch cover 20, extends along that side of the hatch cover, and then doubles back on itself to run parallel to the cable 36 along the side of the hatch cover and along the top of the container, then down the adjacent edge of the side 1 1 of the container and along the lower margin of that side, to be secured to the control lever 35.

For clarity, the cables 30, 31 and 36, 37 are depicted as exposed cables, and could be arranged in this way, but preferably the cables would be protected by conduits.

The control lever 35 is mounted centrally on one of the longer sides 1 1 and comprises a telescopic bar 40 which is pivoted to the side of the container at a pivot 41 . The end of the bar 40 opposite to the pivot 41 is apertured and is mounted on a bearing and arranged to slide in the directions of arrows A and B on a guide bar 42 which is supported horizontally across the side 1 1 by support brackets 43.

When the control lever 35 is in the position shown in Figures 6 and 7, the hatch cover 20 is closed. To open the hatch cover 20, the control lever 35 is pivoted towards the open position using handle 44, by sliding the telescopic bar 40 along the bar 42 until the lower end of the control lever lies in the open position. As the telescopic bar 40 pivots on the pivot 41 , the bar 40 can telescope to shorten or lengthen as necessary. As the control lever 35 is moved from the closed to the open position, the lever pulls the cables 30, 31 with it as it moves, pulling the hatch cover 20 in the direction of Arrow C (Figure 4).

To open the hatch 20, the control lever 35 is pivoted back to the closed position by sliding the telescopic bar 40 along the bar 42, in the direction of Arrow B (Figure 7). The cables 36, 37 move with the control lever 35 to pull the hatch cover in the direction of Arrow D (Figure 5) until the hatch cover lies in the closed position.

Provision may be made for locking the control lever 35 in either or both of the open and closed positions, to prevent accidental movement or tampering.

It will be appreciated that both the opening and closing movements of the hatch cover are positive movements in that in both cases the hatch cover is pulled into position. Further, the cable connection mechanism is simple to operate, can easily be repaired if damaged, and is operated by a user standing at one side of the container:- there is no need for the user to climb on top of the container; this is both quicker and much safer.

The cables 30, 31 , 36, 37 may be any suitable type of cable but preferably are Morse cables.

An alternative design for the control lever 35 is to use a solid bar 40a in place of the telescopic bar 40. To accommodate the changes in length of the bar 40a as it is pivoted on the pivot 41 , the bearing on the bar 40a which slides on the guide bar 42 is formed with a slot to accommodate the changes in length of the bar 40a as it moves along the guide bar 42.

Another example embodiment of the invention will now be described below in detail with reference to Figures 8 and 9; this embodiment is identical to the top hatch design described with reference to Figures 1 - 7, except as set out below. In referring to the drawings, the same reference numerals are used as in Figures 1 - 7 above. As shown in Figure 8, the control lever 35 shown in the embodiment of Figures 1 - 7 is replaced by a control lever 50 which is pivoted to the side 1 1 at a point 51 about two thirds along the length of the control lever 50. The pivot point 51 is closer to the top 14 of the container 10, so as to give a user operating the handle 44 to pivot the control lever the maximum mechanical advantage.

The lower end 52 of the control lever 50 adjacent the handle 44 is arranged to slide along a guide rod 42, as described with reference to Figure 6 of application 201 1 /900814. The control lever 50 may be telescopic or mounted on a slotted bearing, as described with reference to the embodiment of Figures 1 - 7.

The upper end 57 of the control lever 50 is arranged to slide along a guide rod 58 which is mounted along the top of the side 1 1 , parallel to the guide rod 42.

In the embodiment of Figures 8 and 9, the cables 55, 56 are attached to the upper end 57 of the control lever 50. This reduces the length of the cables required.

The cables 55, 56 operate to pull the hatch cover 20 between the open and closed positions in the same manner as described with reference to Figures 1 - 7.

Referring to Figure 9, the hatch cover 20 is arranged to slide over a filling aperture 15 formed in the top 14 of the bulk container 10, in the same manner as described with reference to Figures 1 - 7. The hatch cover 20 is moved between the closed position shown in Figure 9 and the open position, in which the hatch cover 20 is moved clear of the filling aperture 15, by means of the cables 55, 56, both of which are secured to the upper end 57 of the control lever 50.

The cable 55 is secured at one end 55a to the upper end 57 of the lever 50 extends in a loop around the top 14 of the container, is rigidly secured along one side 58 of the hatch cover 20, and then continues around the perimeter of the top 14 of the container, with the other end of the cable 55b secured to the opposite side of the upper end 57 of the lever 50 to the first end of the cable 55a. The cable 56 has one end 56a secured to the same side of the upper end 57 of the lever 50 as the end 55a of the cable 55, and is then formed in a loop around a turning point 60 to double back on itself and extend along the perimeter of the top 14 and then along the side 59 of the hatch cover 20, opposite to the side 58. The cable 56 is rigidly secured to the side 59 and then is looped back on itself around a turning point 61 to return along a parallel course to be secured at the other end 56b to the same side of the upper end 57 of the control lever 50 as the end 55b of the cable 55.

Figure 9 shows the hatch cover 20 closed. To open the hatch cover, the lever 50 is pivoted about the pivot 51 in the direction of arrow A to pull the ends 55b and 56b of the cables 55, 56 in the direction of arrow A. Since the cables 55, 56 are rigidly secured to the sides 58, 59, respectively of the hatch cover 20, movement of the cables in the direction of arrow A slides the hatch cover in the direction of arrow D, to the open position.

When the hatch cover is to be closed, the lever 50 is pivoted about the pivot 51 in the direction of arrow B. This moves the ends 55a, 56a of the cables 55, 56 in the direction of arrow B, and slides the hatch cover 20 in the direction of arrow C, i.e. back into the closed position.

As with the embodiment described with reference to Figures 1 - 7, cables 55 and 56 may be any suitable type of cable but preferably are Morse cables.

For clarity, the cables 55, 56, are shown as exposed cables, but preferably would be protected by conduits. Claims

1 . A top hatch for a bulk container which includes a hatch cover which is arranged to slide between an open position to allow access to an aperture in the top of a bulk container, and a closed position to close said upper aperture in the bulk container; wherein the sliding movement between open and closed positions is controlled by a control means adapted to be mounted on the side of the container.

2. The top hatch as claimed in claim 1 wherein said sliding movement of the hatch cover between the open and closed positions is achieved by cables connected between the hatch cover and the control means.

3. The top hatch as claimed in claim 2, wherein said cables are arranged such that the movement of the hatch cover from the open position to the closed position, or from the closed position to the open position, is achieved by pulling one or more of the cables.

4. The top hatch as claimed in claim 1 , wherein said control means includes a lever adapted to be pivotally mounted on the side of the container.

5. The top hatch as claimed in claim 3, wherein said control means includes a lever adapted to be pivotally mounted on the side of the container, said cables being connected to said lever such that movement of said lever pulls said cables.

6. The top hatch as claimed in claim 5, wherein said lever is adapted to be pivotally mounted on the side of the container at the upper end of the lever, and said cables are connected to the lower end of said lever.

7. The top hatch as claimed in claim 6, wherein the hatch cover is movable from the open to the closed position by means of a first pair of cables, each of which is secured at one end to one side of the hatch cover and at the other end to the lower end of said lever; and the hatch cover is movable from the closed to the open position by means of a second pair of cables, each of which is secured at one end to the opposite side of the hatch cover and at the other end to the lower end of said lever.