GB2039842A

GB2039842A - Discharging Container Contents

Info

Publication number: GB2039842A
Application number: GB7902439A
Authority: GB
Original assignee: FAIRBAIRN LAWSON PACKAGING Ltd
Current assignee: FAIRBAIRN LAWSON PACKAGING Ltd
Priority date: 1979-01-23
Filing date: 1979-01-23
Publication date: 1980-08-20

Abstract

To discharge fluent materials from a flexible bulk container 10 a spade 12 is located in a "pocket" in the base of the container so that it becomes suspended from the container. The spade has an aperture 13 and a slidable shutter for opening and closing the aperture. The base of the container is slit through the aperture to provide an outlet capable of being regulated by the shutter. <IMAGE>

Description

SPECIFICATION Flexible Buik Containers and a Method and Means for Regulating the Discharge of Material Therefrom This invention is concerned with the discharge of fluent aterial such as powdered or granular material, from flexible bulk containers, and the invention includes a flexible bulk container, a method of controlling the discharge of fluent material from a flexible bulk container, and a discharge control device for use with a flexible bulk container.

Flexible bulk containers are essentially large bags or sacks, generally made of woven plastics material. One well known type of flexible bulk container, is woven from flat polypropylene tape, the weaving taking place without twisting of the tape, so that there are virtually no interstices between the warp and weft yarns in the finished fabric. The bulk containers are fabricated by stitching or by use of other known means, and whilst the detailed design varies from one type of bulk container to another, essentially they all consist of a base, side walls, and lifting means attached to or forming part of the side walls. Such a flexible bulk container may be made from a single piece of woven material, or from a plurality of pieces of woven material secured together.

The lifting means employed, may take the form of webbing or rope material, or it may be constructed from the same material as the body of the container. Such lifting means is intended to be used with mechanical lifting equipment, for example, a crane fitted with a hook, but fork lift trucks or modified agricultural tractors are also widely employed for lifting the containers.

Sometimes, these have to be provided with a special hook, or in the case of a fork lift truck, the forks themselves can be used in association with the lifting means on the container.

The capacity of flexible bulk containers varies, but the containers in general use, fall within the range 500 to 2500 kilogrammes weight of contents. The contents themselves, vary from powders, to quite coarse granular material. Prilled urea based fertilizers for agricultural use are a typical load for bulk containers of this kind.

The method whereby the contents of the containers are emptied by the end user varies, according to circumstances, but generally the method is based upon the container itself being supported clear of ground level by the lifting means, and cutting through the base of the container with a sharp knife, or other cutter, the length of the cut being estimated, in order to provide a satisfactory rate of flow of the fluent contents of the container out through the opening formed by the cut. Another method which is sometimes used, is to provide an emptying spout which is sewn into the base of the container, and which is tied off, until discharge of the contents is required. However, this considerably increases the cost of the container itself.

It will be appreciated, that it is necessary for a receiving hopper or other open container to be positioned beneath the container in order to receive the contents when the latter are discharged from the container. Apart from the difficulty of estimating the correct size of opening to provide a satisfactory rate of flow if the slitting method is used, or the high cost of the container if an emptying spout is fitted, these known methods of discharging the contents are likely to give rise to the generation of dust, which in some cases may represent a health risk to the operators.

It is the principle object of the present invention therefore, to provide a method and means, whereby the discharge of the contents of a flexible bulk container, can be satisfactorily regulated.

It has been found, that users of material which is supplied to them in flexible bulk containers frequently require a means whereby the container can be quickly and conveniently connected to a flexible discharge hose, in order to be able to direct the discharge to a convenient position, which may not be immediately beneath the container, or to provide a means of coupling the container to some form of conveyor. A secondary object of the invention therefore, is to provide a means whereby a discharge conduit can conveniently be attached to the container.

Furthermore, it has been found in practice that users of the material supplied to them in flexible bulk containers are often desirous of a means of conveniently starting and stopping the flow of material from the container, so that it is notnecessary to discharge the whole contents of the container at a single operation. Frequently, the users would also find it advantageous to have a means of regulating the rate at which the fluent material is discharged from the containers. It is a further object of the present invention therefore, to provide means whereby these desiderata can be achieved.

One form of flexible bulk container with which the present invention is particularly well adapted for use, is described in United Kingdom Patent Specification No: 1475019, and improvements to this flexible bulk container are described in United Kingdom Patent Applications Nos: 7374/78 and 7375/78. The container described in the said United Kingdom Patent and Patent Applications has a special construction, whereby the base or bottom of the container is formed and closed.

Whilst the present invention, has been developed with a view to use in connection with flexible bulk containers having base formations as described in the said United Kingdom Patent and pending applications, it may also be used with other designs and constructions of flexible bulk containers.

According to one aspect of the invention, a flexible bulk container is fitted with a discharge control device in the form of an apertured platter having a slidable shutter for closing its aperture, the platter being suspended from the container and lying beneath the base of the container, there being an outlet in the base of the container registering with the aperture in the platter.

Preferably, the platter is suspended from the container by a web extending under the base of the container from side-to-side thereof and joined to the container base and/or walls only at the sides, so that the platter is received in the openended "pocket" between the base and the web. It is further preferred that the outlet in the base of the container is formed by slits which form one or more openable flaps in the base.

Further, it is preferred that the platter is in accordance with the third aspect of the invention as set forth below.

According to a second aspect of the invention, a method of controlling the discharge of fluent material from a flexible bulk container comprises the steps of: positioning an apertured platter with a slidable shutter for closing the aperture thereof immediately below the base of the container, with the shutter in an open position; forming an outlet in the base of the container by rupturing the base through the aperture to form an outlet opening, and manipulating the shutter to regulate the size of the discharge opening provided by the outlet opening and the aperture.

According to a third aspect of the invention a discharge control device for use with a flexible bulk container comprises a platter formed with a nose at one end to facilitate penetration of the platter into a "pocket" formed in a flexible container, the platter having an aperture and a shutter adapted to slide between a position where it closes the aperture and a position where it opens the aperture.

According to a preferred arrangement, the shutter is sandwiched between two laminations of the platter, the aperture being formed through both laminations. Preferably, the shutter projects from one end of the platter, and is provided with a hand grip at the projection. The platter itself is also preferably provided with a pair of hand grips one at each side.

According to another preferred feature of this third aspect of the invention, the platter is provided with attachment means for releasably attaching a conduit to the platter in a position such that the material discharging from the flexible container through the aperture will flow into the conduit. The attachment means may comprise an annular member secured to the underside of the platter around the aperture and having one or more formations for securing one end of a conduit to it by relative turning movement between the conduit and the annular member.

The invention in all three aspects, will be better understood from the following description of a bulk container, discharge means for use with the bulk container, and the method of using the discharge means, all of which are described herein by way of examples only, with reference to the accompanying drawings, in which:: Figure 1 is a perspective view of a flexible bulk container during the course of its construction, Figure 2 is a perspective view similar to Figure 1, but showing a further stage in the construction of the container, Figure 3 is a view similar to Figures 1 and 2, but showing the completed container, Figure 4 is a perspective view, showing a container constructed as illustrated in Figures 1 to 3, but fitted with lifting means, and suspended from a hook, Figure 5 illustrates the lower portion of the container shown in Figure 4, and the iisertion of a discharge control "spade", Figure 6 is a perspective view partly in section, of the spade shown in Figure 5, Figure 7 is an underneath perspective view of the spade shown in Figures 5 and 6, Figure 8 is a perspective view from underneath the container shown in Figure 5, after the spade has been fitted, and showing a step in the opening of the container, Figure 9 is a view looking in the direction of arrow IX in Figure 8, Figure 10 is a view similar to Figure 8, but to a larger scale, showing a further stage in the opening of the container, and Figure 11 is a perspective view of the lower portion of a bulk container, fitted with a flexible discharge conduit.

A flexible bulk container 1 in this instance, is produced from a single sheet of fabric made of woven flat polypropylene tape, as previously described, the piece of fabric being formed into four equal walls arranged in a rectangular fashion, the ends of the fabric being joined together by stitching or welding, along a vertical corner of the container. The fabric is slit at the corners of the four walls, so that four substantially identical flaps 2, 3, 4 and 5 are provided, one at the lower end of each of the four walls of the container. A pair of opposite flaps 2 and 4 are brought together by bending across the bottom of the container, and their extremities are sewn together or otherwise joined to form a joint line 6 (see Figure 2). The two flaps 2 and 4, thus form the base of the container 1.

The two remaining opposite flaps 3 and 5, are then brought together in the same way as the first pair of flaps 2 and 4 and their extremities joined by sewing or other means, forming a second joint line 7 disposed at right angles to the first joint line 6. Thus, the container can be considered as having a double walled base, the upper wall being constituted by the flaps 2 and 4, and the lower wall by the flaps 3 and 5. However, for present purposes, the fabric constituted by the flaps 3 and 5, will be referred to as a web under the base constituted by the flaps 2 and 4, and since this web is only joined to the side walls of the container 1 at the sides, there is an open ended "pocket" 11 formed between the base and the web.

Figure 4 shows a container 10 constructed as described above, but fitted with a pair of lifting straps 9, and in Figure 4, the container is shown in a filled condition, suspended from the hook 8 of a crane, lift truck or similar lifting apparatus (not shown) the container being lifted by the lifting apparatus, to a convenient height above ground level for discharging into a hopper, or onto a conveyor. In this condition, it will be appreciated that the base of the container is pressed tightly against the web, giving a double layer effective base, but there is some access between the two layers, through the slightly open mouth 11 at each side of the container.

For the purpose of regulating the flow of material from the containers, a spade 12, illustrated in Figures 5, 6 and 7 is provided. The spade 12 has a body which generally takes the form of an elongate rectangular platter, with a rounded nose portion 1 2a at its leading end. The laminated construction includes top and bottom members 1 2b and 1 2c, spaced apart by longitudinally extending edge members 1 2d, so that a shaliow cavity 1 2e of approximately the same depth as the edge members 1 2d is formed internally of the body 1 2b. The cavity 1 2e, opens out at the trailing end of the body 12, and a platelike shutter 1 4 is fitted within the cavity 1 2e, one end of the shutter 14 extending out through the trailing end of the spade 12, as shown in Figures 6 and 7.A slot 1 5 is formed through this trailing end of the shutter 14, to provide a hand grip, whereby the shutter can be manipulated, with a permitted sliding movement longitudinally with respect to the body 12 of the spade.

A circular aperture 13 is formed through both the upper and lower members 1 2b and 1 2c of the spade, so that when the shutter 14 is retracted rearwardly with respect to the spade, there is a circular passage through the cavity 13, but when the shutter 14 is pushed forwardly with respect to the body of the spade, the forward end of the shutter acts as an obturator for the cavity 1 3, and in this way, a "hit-and-miss" valve is provided by the spade 12.

A pair of handles 16 is provided at the trailing end of the body of the spade, for manipulating the spade itself, and for holding the body of the spade, whilst the shutter 14 is manipulated with its sliding action.

An annular metal flange 18 is secured to the under surface 1 7 of the spade, this flange extending around the underside of the aperture 13. The flange has an inner portion 1 8a (see Figure 9) which is joggled downwardly with respect to the outer portion of the flange, so that it is spaced slightly from the under surface 1 7 of the body of the spade. A pair of rectangular slots 1 8b is formed in the joggled inner portion 1 8a of the flange, and these slots are open on the inside of the flange.

A flexible conduit for use with the spade 12, is illustrated at 23 in Figure 11. This conduit is of conventional construction, and is fitted with a metal funnel 22 at its inlet end. This funnel has a pair of lugs extending radially outwardly, at its outer extremity, the outside diameter of the funnel 22, being a close fit within the bore of the flange 1 8 fitted to the spade 12.

If it is required to connect the flexible conduit 23 to the spade, then the pegs on the funnel 22 must be aligned with the slots 1 8b in the flange, and the funnel inserted into the bore of the flange.

The pegs can then enter the space between the joggled portion 1 8a of the flange and the under surface 1 7 of the spade, and by rotating the funnel 22 with respect to the spade, the pegs are moved into positions under the joggled portion 1 8a whereby the funnel 22 becomes tightly secured to the spade.

Assuming that the flexible bulk container 10 in the position illustrated in Figure 4 has to be emptied, the nose end of the spade is introduced into the mouth indicated at 11, and then the spade is pushed manually into the "pocket" between the base and the web of the container, until the aperture 13 is under the centre of the base. At this stage, the spade is attached to the container 10, being suspended therefrom, by the web which extends under the base.

The shutter 14 is slid forwardly into the fully closed position, and at this stage, a circular hole 19 is cut in the web by use of a knife. This cutting operation, is facilitated by the metal flange, since either the periphery of the flange itself, or the effective boss formed by the joggled portion 1 8a can be used as a guide for the cutting operation.

When the material cut out from the web has been removed, then the flange 1 8 and the underside of the shutter 14 which obscures the aperture 13, are visible from the underside.

The shutter 14 is then retracted approximately half way across the aperture 13, so that the leading edge of the shutter extends across a diameter of the aperture. Again using the knife, a semi-circular incision 20 is formed through the base of the container, using the inside diameter of the flange 18 as a guide. The shutter 14 is then withdrawn to a position illustrated in Figure 10, and the knife is pressed through the base fabric, in the position shown in Figure 10, where the rear edge of the knife blade rests against the leading edge of the shutter. Holding the knife in one hand, and the handle of the shutter in the other, the operative then pushes both the knife and the shutter forwardly, making a diametral cut 21 across the portion of the base of the container which is exposed through the aperture 13, until the cut 21 joins the semi-circular cut 20 previously formed.

By these two cutting operations, two quarter circle flaps are formed in the base of the bag, which are able to open downwardly, to allow the contents of the bag to discharge through the aperture 13. It has been found, that this provides a very satisfactory method of opening the base of the bag. However, since the shutter 14 has been moving across the aperture 1 3 during the second cutting action, when the knife is finally withdrawn, and the shutter pushed to its forward extremity, the aperture 1 3 will be closed, and material cannot escape from the container 10, because the flaps formed by the cutting operation are resting on the top side of the shutter 14.

The container is then ready for discharging as and when required. When it is necessary to remove material from the container, it is only necessary to retract the shutter by a desired amount, and this will allow the fluent material to pour out through the aperture 1 3. If it is required to arrest the discharge of material, this can be achieved simply by pushing the shutter forwardly, to close off the aperture 13. It will also be appreciated, that it is possible to regulate the rate of flow of material from the container 10, by adjusting the position of the shutter 14 with respect to the body of the spade 12.

When the container 10 is completely empty, it is of course possible to remove the spade 12, and use it with another container. Hence, the user need only have a single spade, for each position at his works, where unloading of the material from a container 10 is required.

If it is required to feed the material from the container through a conduit such as the conduit 23, then after the slits have been formed in the base of the container, and whilst the shutter 14 is still in the closed position, the funnel 22 is fitted to the flange 18, and then when the shutter is moved to the open position, the material discharging from the container 10 flows through the conduit 23. In a typical installation, the conduit 23 may be of a length to enable the flow of material to be directed by hand into hoppers or similar equipment.

The dimensions of the spade and its component parts are not critical, but a typical size would be 1.5 metres long, 0.4 metres wide and 12 millimetres thick. The aperture 13 may be in the order of 0.2 metres diameter. With a spade of these typical dimensions, the shutter would be of the order of 0.25 metres wide and 3 millimetres thick. It is envisaged that the spade and its shutter might be fabricated from marine plywood, since this material will facilitate construction, and offers freedom from deterioration due to the weather or exposure to the contents of the flexible containers being emptied. However, it will be appreciated that the spade could be made in plastics material or sheet steel.

Whilst the connection between the funnel 22 and the flange 18 described above, is of the "quick release 1/4 tum" type, it will be appreciated that other releasable connections may be employed. The flange 18 is arranged to project the minimal amount from the lower surface 1 7 of the spade 12, and if necessary could be recessed into the body of the spade, so as to keep the overall thickness of the spade to a minimum. It will be appreciated, that it is desirable to keep the spade as thin as possible, consistent with it possessing the necessary strength properties, in order that the spade may be slid into the "pocket" between the base and the web of the flexible container.

Claims

1. A flexible bulk container fitted with a discharge control device in the form of an apertured platter having a slidable shutter for closing its aperture, the platter being suspended from the container and lying beneath the base of the container, there being an outlet in the base of the container registering with the aperture in the platter.

2. A flexible bulk container as claimed in Claim 1, in which the platter is suspended from the container by a web extending under the base of the container from sideto-side thereof and joined to the container base and/or walls only at the sides, so that the platter is received in the openended "pocket" between the base and the web.

3. A flexible bulk container as claimed in Claim 1 or Claim 2, in which the outlet in the base of the container is formed by slits which form one or more openable flaps in the base.

4. A method of controlling the discharge of fluent material from a flexible bulk container comprising the steps of: positioning an apertured platter with a slidable shutter for closing the aperture thereof immediately below the base of the container, with the shutter in an open position; forming an outlet in the base of the container by rupturing the base through the aperture to form an outlet opening, and manipulating the shutter to regulate the size of the discharge opening provided by the outlet opening and the aperture.

5. A discharge control device for use with a flexible bulk container comprising a platter formed with a nose at one end to facilitate penetration of the platter into a "pocket" formed in a flexible container, the platter having an aperture and a shutter adapted to slide between a position where it closes the aperture and a position where it opens the aperture.

6. A discharge control device as claimed in Claim 5, in which the shutter is sandwiched between two laminations of the platter, the aperture being formed through both laminations.

7. A discharge control device as claimed in Claim 5 or Claim 6, in which the shutter projects from one end of the platter, and is provided with a hand grip at the projection.

8. A discharge control device as claimed in any one of Claims 5 to 7, in which the platter itself is provided with a pair of hand grips one at each side.

9. A discharge control device as claimed in any one of Claims 5 to 8, in which the platter is provided with attachment means for releasably attaching a conduit to the platter in a position such that the material discharging from the flexible container through the aperture will flow into the conduit.

10. A discharge control device as claimed in Claim 9, in which the attachment means comprises an annular member secured to the underside of the platter around the aperture and having one or more formations for securing one end of a conduit to it by relative turning movement between the conduit and the annular member.

11. A discharge control device constructed and arranged substantially as herein described with reference to the accompanying drawings.

12. A flexible bulk container as claimed in Claim 1, in which the discharge control device is in accordance with any one of Claims 5 to 11.

1 3. A method of controlling the discharge of fluent material from a flexible bulk container, substantially as herein described with reference to the accompanying drawings.