Dispensing – Collapsible wall-type container – With casing or support
Reexamination Certificate
2000-06-01
2002-11-19
Yuen, Henry C. (Department: 3754)
Dispensing
Collapsible wall-type container
With casing or support
C220S001600
Reexamination Certificate
active
06481598
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to the unloading of fluid-like or flowable cargo in a container lined with a container liner. In particular, it relates to a container liner with displacement means for moving the contents of the liner towards a discharge opening in the liner.
2. Background Art
Bulk cargo containers are used for transportation of a variety of products. For some products, it is advantageous to fit the container with a flexible liner of e.g. polyethylene or the like. Powered, granular or other flowable materials can be loaded directly from a storage space, such as a silo or the like and into the liner of the container saving a packaging operation by the manufacturer while also making more efficient use of the container space, as packaging materials, such as bags, pallets, etc. do not have to be transported with the products.
The product in the container can subsequently be unloaded and transferred directly into a new storage space with tie recipient. All in all, the whole handling process is considerably easier and a lot less expensive. The product can be discharged from the container liner by tilting the container whereby the powdered, granular or similarly flowable material flows under gravity towards and out of a discharge open at the lower end of the container liner.
However, some of the powdered or granular material is usually trapped in the lower corner regions of the container. In order to move the powdered material towards the discharge, it is known to mount triangular corners, to minimise the likelihood of products accumulating in the corner regions during the discharge operation. An example of such rigid angled corners integrated in a bulkhead is known from U.S. Pat. No. 4,799,607. From U.S. Pat No. 5,531,361, an active bulkhead is known where tetrahedron-shaped inflatable bags are mounted in the lower corners on each side of the discharge. Similarly, inflatable tetrahedrons mounted inside the container liner are known from U.S. Pat. No. 5,489,037.
From international patent application No. WO 95/01925, another solution is known. Here, two inflatable bladders are provided at each lower corner region at the discharge end of the liner.
By these known solutions, the material in the corner regions of the liner is lifted up in the corner region whereby the angle of dip of the material might be exceeded causing the material to slide towards the centre of the container liner. The size of the inflatable corners are relatively restricted due to the design of the corners. Moreover, the lifting of the material in the corners by inflating the corners produces an immense stress in the walls of the corners as well as the walls of the liner itself. This stress is caused by the air pressure in the inflated corner deriving from the pressurised air source filling the corner as well as the load of the material being lifted. This means that the material in the liner just outside the area exposed to impact by the inflating liner could form a dip in the liner creating stress in the liner wall as well.
Such stress can cause the corners or even the liner itself to burst which is unfortunate for obvious reasons as the material is thereby wasted with all the distressing implications associated therewith.
In the above mentioned U.S. Pat. No. 5,531,361, a vibrating mechanism is installed for vibration of the rigid support surface of the corner lifting the liner corner. Hereby, the flow of the material is eased and the discharge flow is enhanced.
However such bulkhead designs take up a lot of space in the container whereby the space for storing the products to be transported is reduced.
It is the object of the invention to provide an improved liner and a method of discharging said liner in such a manner that the above-mentioned drawbacks with the existing liners on the market are avoided.
SUMMARY OF THE INVENTION
This object is achieved by the present invention consisting of a liner for use in a box-like cargo container for transportation of powder, granular or other flowable products, said liner comprising top and bottom walls, two side walls and first and second end wall portions corresponding to the wall portions of the container, a discharge opening at the lower portion of said first end wall, through which the contents of the liner are discharged, displacement means for guiding the content of material towards said discharge opening, said displacement means comprising at least one inflatable, flexible bag having an essentially triangular or trapezoid shape substantively abutting said end first wall, and a first essentially triangular portion supporting the outside surface of the floor and a second essentially triangular portion supporting the adjacent side wall portion of the liner, said triangular bag comprising three corners positioned substantively at the edge of the end wall and the side wall portion, the end wall and the bottom wall portion, and the side wall and the bottom wall portion
By the present invention, an inflatable bag is provided that moves the material in the liner sideways towards said discharge opening. An inflatable bag according to the invention has an essentially triangular shape and is aligned with the end wall and is attached to the liner along the edge of the side wall and the floor of the liner. This means that the material is not lifted but pushed sideways away from the side wall of the corner region of the container. The stress implied in the bag as well as in the liner is thereby reduced considerably.
In particular, the upper corner portion of the flexible bag is provided with a flexible inflation tube for inflation of the flexible bag with pressurised air causing the inflation to advance from the upper portion and downwards in the bag as the amount of material in the liner is reduced. This means that the pressurised air in the flexible bag distributes itself in the correct manner causing the material to “roll”. The upper portion of the material trapped in the corners at any given time is pushed sideways by the progressing inflation of the bag whereby the angle of dip is exceeded and the material slides down towards the discharge opening. The method and design of the liner relieve the material from excessive stress thus eliminating the risk of overloading and bursting the bags and/or the liner itself during the discharge operation.
In addition, the discharge operation is more efficient since the bags can be designed in considerably larger dimensions without increasing the risk of causing the bag to burst due to excessive internal pressure.
Moreover, by attaching the triangular flexible bags to the outside surface of the liner by a number of individual double adhesive strips, the liner occupies a minimum of space when folded together and shipped off to the point of use. Also, a liner with flexible corner bags according to the invention can be manufactured in a simple and inexpensive manner. The points of attachment can be chosen in accordance with the desired impact of the inflated bag on the corner region of the liner.
In a preferred embodiment, the inflatable bag comprises two essentially triangular or trapezoid, flexible sheets secured to each other in a gas-tight manner along the edges forming an interior space that can be increased in volume by inflation with pressurised air. Hereby, the manufacture of the flexible inflatable bags is simple and the production is easily altered to accommodate different sizes of bags. Moreover, the bags hardly occupy any space when deflated.
In the preferred embodiment, two flexible sheets are of an elastomeric material, preferably polyethylene, polypropylene or the like, said sheets being secured to each other by welding. The inflation tube comprises a first end that is preferably welded to the upper corner portion of the sheets forming the bag, said sheets being provided with a non-adhesive paper sheet prior to their assembly, such as a heat-transporting grease-proof paper sheet, said paper sheet being positioned in the opening of said first end of the inflation tube.
Buechner Patrick
Caretex A/S
Merchant & Gould P.C.
Yuen Henry C.
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