AU759428B2 - Tilting stand for bulk container - Google Patents

Description

P00011 Regulation 3.2 Revised 2/98

AUSTRALIA

Patents Act, 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT TO BE COMPLETED BY THE APPLICANT NAME OF APPLICANT: oo oo BRAMBLES AUSTRALIA LIMITED ACTUAL INVENTOR: ADDRESS FOR SERVICE: INVENTION TITLE: DETAILS OF ASSOCIATED PROVISIONAL APPLICATION NO: Peter Maxwell Associates Level 6 Pitt Street SYDNEY NSW 2000 TILTING STAND FOR BULK CONTAINER PP 8547 8 February 1999 Australia The following statement is a full description of this invention including the best method of performing it known to us:- 2 This invention relates to stands for bulk containers and more particularly to a stand which tilts so as to aid in the discharge of the contents of the container.

In their most basic form, intermediate bulk containers (IBCs) are a "pallet cage". This is a product that has a pallet as its base, and to which "cage side-sections" can be added to construct a container into which customers then load their products.

More sophisticated IBCs have a "steel pallet base" with folding sides attached to them. These products are easy to assemble and disassemble and offer excellent relocation efficiency. By using liner bags inside them, IBCs have found new and high growth markets, particularly in the food and chemical industries.

The highest growth has been achieved in the "liquids market" where due S* to their increased efficiency and lower cost, IBC units are displacing large o 15 numbers of 44 gallon/200 litre drums.

However, when the base of the IBC is parallel to the ground, it is difficult to dispense the entire contents.

Itis an object of the invention to provide a device and method for more efficient emptying of IBCs.

According to one aspect of the invention there is provided a tilting stand for an intermediate bulk container, the stand having a forward end defined by the direction of discharge, the stand comprising:a rigid frame; the frame having an upper deck; opposing pivots extending from the upper deck to a container support; a lifting cylinder extending between the frame and the container support; a one way pressure valve connected to an input of the lifting cylinder for maintaining a constant, pre-established minimum pressure to the lifting cylinder so that the lifting cylinder acts like a spring.

00000In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings in o.

S•which:- Fig. 1 is a top plan view of a tilting stand; Fig. 2 is a side elevation of the stand shown in Fig. 1 in a resting position; Fig. 3 is a side elevation of the stand shown in Fig. 1 in a tilted position; Fig. 4 is a side elevation of a gravity powered stand in an initial o or rest position; 15 Fig. 5 is a side elevation of the stand shown in Fig. 4 in a charged position; and Fig. 6 is a side elevation of the stand shown in Fig. 1 in a tilted position.

As shown in Figs. 1 to 3, a tilting stand 10 comprises a rigid base or frame 11 and a pivoting container support 12. The frame 11 comprises an upper deck 101 supported above a lower deck 102 by legs 103. The lower deck 102 rests at ground level. In this embodiment, the support 12 is attached to the base 11 with two opposed pivots 13. A pneumatic (or hydraulic) lifting cylinder 14 extends between the frame 11 and the support 12. Multiple cylinders may be employed.

An intermediate bulk container IBC is intended to be deposited onto the upper surface 15 of the support 12. The IBC faces and discharges forward in the direction of arrow 16. In the initial or down position, the cylinder 14 is located somewhat behind the centre of the load. The pivots 13 are located somewhat forward of the initial load. Using a 1200mm long IBC as an example, the cylinder 14 may be located 650mm from the front edge of the support 12 with the pivots 13 located 450mm from the front edge.

In this embodiment, the cylinder's fluid chamber 105 pivots with respect to the lower deck 102 and the rod 106 pivots with respect to the upper deck 101 where it is attached.

~Pressure regulation and control are provided by valves (for example a single ball valve) and fittings 17 supported on an arm 18 which places the controls at a convenient height for the operator. In this embodiment, the °cylinder 14 is preferably a pneumatic cylinder and working pressure is supplied from an external line. The pressure to the cylinder 14 is pre-set (for example to 80 psi) so that the support 12 tilts forward approximately 15-20 degrees when the contents of the IBC falls to about 20 percent of its initial capacity. The main cylinder 14 acts like a spring.

The tilting support 12 includes a safety stop or limit 70 which creates a mechanical interference and thus a permanent minimum clearance between the support 12 and the base 11. The safety stop or limit 70 may also be mounted on the base 11.

As depicted in Figs. 4 to 6, a tilting stand is capable of being powered by gravity. In this embodiment, the frame 20 includes a base 21 and a sub-frame 22. Upright cylindrical legs 23 affixed to the corners of the base 21 slide within the sub-frame's hollow cylindrical legs 34. This telescopic action allows the sub-frame 22 to rise and fall with respect to the base 21. An IBC support 35 is connected by opposing pivots 36 to the upper deck 37 of the sub-frame 22.

A main hydraulic cylinder 38 connects the support 35 to the base 21. In this embodiment, water is an acceptable hydraulic fluid. The main cylinder 38 is centrally located, but located behind the pivots 36. Four smaller cylinders 39, located toward the corners, inboard of the telescopic legs, support the subframe 22 relative to the base 21. The main and smaller or secondary corner cylinders 39 are all hydraulically connected to an inelastic gas and liquid reservoir 40. The gas (usually air) within the reservoir 40 is pre-compressed and compressed further when the fluid level in the reservoir 40 rises. Fluid rises in the reservoir when it is pumped into the reservoir 40 by the main or smaller cylinders. Gas pressure which accumulates in the reservoir 40 is used to selectively pump fluid from the reservoir to the main cylinder 38 alone for tilting the IBC and into the smaller cylinders 39 for returning the sub-frame 22 and support 35 to the initial position. The duty cycle is explained more fully below.

In its rest position (Fig. there is no load on the IBC support and all olooo main and corner cylinders are fully extended. The IBC support 35 is parallel with the base 21 and is maintained in a parallel relationship by a safety lock 41.

The safety lock 41 comprises a hinged or otherwise pivoting cover plate 43 and pin 44. The spring biased retractable pin 44 extends from the upper deck 37 into the IBC support 35 and locks the IBC support 35 to the frame. Only when the plate 43 is pivoted or moved out of the way (against gravity) can the pin be accessed. This same safety feature may be fitted to the device shown in Figs.

1 to 3.

Fig. 5 illustrates the charged position. The stand is charged by lowering the loaded IBC using, for example, a fork lift. This lowering compresses the main cylinder 38 and corner cylinders 39 and diverts the associated flow of liquid into the reservoir 40. This rising liquid causes the gas in the reservoir to compress. When the reservoir 40 is charged, the ball valve is set to prevent fluid to flow into the corner cylinders 39. The telescopic legs stabilise the subframe 22 and protect the cylinders from excessive shear loads.

In the charged condition (Fig. all cylinders are lowered and the reservoir's gas pressure is adequate to complete the duty cycle. This entails both tilting the support 35 and IBC when the IBC is about 20 percent full and eventually, returning the sub-frame 22 to the rest or initial position at the end of the duty cycle.

The tilting stand 10 is readied for service, from the charged position, when the cover plate 43 is moved out of the way and the pin 44 is withdrawn.

Note from Fig. 6 that the raised safety plate 43 serves as a flag or warning that the support 35 and the IBC are mobile.

In service, the pressure within the reservoir 40 will displace the main cylinder's rod (but not the corner cylinders) and tilt the support 35 when the Sdiminishing weight of the IBC eventually reaches a predetermined limit.

Mechanical constraints restrict the tilting to about 15-20 degrees in the forward direction when about 80 percent of the contents of the IBC have been discharged. This position is illustrated in Fig. 6.

The remaining pressure in the reservoir 40 is used to expand the smaller cylinders 39 and thereby return the sub-frame 22 to its initial or rest position (Fig. This is done by using the ball valve to admit fluid flow into the corner cylinders 39. The duty cycle is completed when the IBC is removed from the support 35, the pin 44 is re-inserted and the cover plate 43 is closed.

Although this description contains certain specific details of construction and method, these should be seen as examples and not as limitations to the scope or spirit of the invention.

Claims (12)

1. A tilting stand for an intermediate bulk container, the stand having a forward end defined by the direction of discharge, the stand comprising:- a rigid frame; the frame having an upper deck; opposing pivots extending from the upper deck to a container support; a lifting cylinder extending between the frame and the container support; a one way pressure valve connected to an input of the lifting cylinder for maintaining a constant, pre-established minimum pressure to the lifting cylinder so that the lifting cylinder acts like a spring. *l

2. The tilting stand of claim 1, wherein: the container support has a centre of load; the opposing pivots being located forward of the centre of load. o•

3. The stand of either of claims 1 or 2, wherein: the upper deck is supported above a lower deck by legs; the lifting cylinder extends from the lower deck to the upper deck.

4. The stand of any of claims 1 to 3, wherein: the lifting cylinder comprises a fluid chamber and rod, each being pivoted at their point of attachment.

The stand of any of claims 1 to 4, wherein: a mechanical safety stop is mounted on either the frame or container support and creates a mechanical limit between the frame and container support and thus a minimum safe clearance between the frame and container support. 0

6. The stand of any one of claims 1 to 5, wherein: the lifting cylinder is a pneumatic cylinder.

7. The stand of any of claims 3 to 5, wherein: the lifting cylinder is a hydraulic cylinder; the legs are telescopic and one leg is disposed in each corner of the stand; a secondary cylinder is located near each leg; 0 the lifting and secondary cylinders each connected to a .:00 hydraulic reservoir; the hydraulic reservoir being partially fillable with a working fluid and also having pressurised gas with it; compression of the secondary cylinders under load causing a gas pressure build up in the reservoir; one or more valves being provided to selectively allow the pressure build up to deliver working fluid to the lifting cylinder but not the secondary cylinder.

8. The stand of claim 7, wherein: the one or more valves allow residual gas pressure in the reservoir to be diverted, when required, to the secondary cylinders, to extend them, but not to the lifting cylinders.

9. The stand of any of claims 2 to 8, wherein: the centre of load is disposed between the lifting cylinder and the forward end.

The stand of any one of claim 1 to 9, wherein: a retractable pin extends between the frame and the container support so as to maintain the container support in a fixed horizontal position when required.

11. The stand of claim 10, wherein: a hinged cover plate covers the pin and only allows the pin's S withdrawal from the container support when the coverplate is displaced, against gravity, to expose the pin.

12. A tilting stand for an intermediate bulk container substantially as hereinbefore described with reference to the accompanying drawings. Dated this 3 day of November, 1999 BRAMBLES AUSTRALIA LIMITED Patent Attorneys for the Applicants PETER MAXWELL ASSOCIATES