GB2077241A - Dispensing particulate materials - Google Patents

Abstract

A hand held rigid or flexible dispenser for particulate materials comprises a container having in its base a plurality of parallel outlet bores formed e.g. by tubes 3 or notably by the internal partitions in a laminated material. An outflow of material is achieved by shaking the container to prevent bridging of particles in the bores. When shaking is stopped, bridging occurs and flow of material through the outlet is halted. <IMAGE>

Description

SPECIFICATION Flow control The present invention relates to a dispenser for particulate materials.

It is often desired to apply particulate materials, e.g. fertilizers, seeds or peat products, to a surface, e.g. a lawn or to the soil. Hitherto, this has been done either by hand broadcasting of the particles (which is slow and relies upon the experience of the operator for its accuracy) or by means of a mechanical spreader (which is often expensive and cumbersome). We have now devised a form of dispenser which reduces these problems.

Accordingly, the present invention provides a container adapted to receive a particulate material and provided with an outlet having a plurality of substantially parallel elongated bores having their inlets adapted to receive particles from the container and having their outlets adapted to discharge material outside the container characterised in that the dimensions of the bores are selected so that bridging of particles across the bores occurs in the absence of particles across the bores occurs in the absence of movement of the container in a motion having a component of direction substantially along the axis of the bores.

For convenience the device of the invention will be described by way of illustration with respect to the preferred form thereof shown in the accompanying drawings in which Figure 1 is a diagrammatic elevational view of the device, Figures 2 to 7 are diagrammatic views of alternative forms of the device of Figure 1. Figure 8 is a diagrammatic plan view of a blank of material from which the device of Figure 1 can be assembled and Figure 9 is a side view of the assembled blank of Figure 8.

The device of the invention comprise a container for the particulate material. This container can be of any suitable shape or size and may be rigid or collapsible. Thus, the container can take the form of a flexible bag or sack or of a squared, rounded or triangular section trough or bin. It is particularly preferred that the container is of a size and form which can readily be carried by a user and is provided with handles, loops or grips by which it can be supported. A convenient form of container is the triangular cross-section trough 1 shown in Figure 1 with the carrying handles 2.

The container can be formed from any suitable material, e.g. metal, wood, plastics, paper or cloth.

A particularly preferred material is a plastics sheet or laminate or the foamed plastics material known as structural plastics. As indicated below it is especially preferred to use a corrugated material which has internal passageways which are used to provide the outlet to the hopper. Thus, the container could be made from corrugated cardboard or its plastics equivalent, notably that material sold under the trade name of Correx.

Such materials can be readily scored or cut whereby the container can be formed by cutting and folding a suitable flat sheet or blank of material. Such a container can be held in shape by forming suitable interlocking tabs and/or slots in the blank or by other suitable fixing means, e.g.

staples, stitches or adhesive.

The container is provided with an outlet which comprises a plurality of substantially parallel elongated bores. The term bore is to be construed herein as including a passageway with any shape of cross-section, e.g. triangular, squared, trapezoidal, polygonal and of regular or irregular shape with or without radial symmetry. Thus, the outlet can be formed by mounting a series of cylindrical tubes side by side, by boring holes through a block or from the internal passageways or flutes formed within a corrugated cardboard or the like. Whilst the outlet can extend over part or all of a generally flat base to the container, we prefer that the container cross-section converge towards the outlet and that, for example the outlet take the form of a row of tubular members mounted along the base of the container as shown in Figure 1.A particularly preferred outlet configuration is that shown in Figure 2 which comprises one or more rows of square section tubes 4 formed along the apex of a triangular cross-section container.

The outlet can be formed as a separate member which is mounted on the container by any suitable means. Thus, as shown in Figure 3, the outlet can take the form of a row of nozzles 3 mounted on a support plate 5 which is then mounted in the base of a container or mounted in an end seam of a sack as shown in Figure 4. However, it is preferred to form the device of the invention from a material which has internal passageways therein, e.g. from corrugated cardboard or Correx, and to expose these passageways to the interior of the container.

Particles within the container can then enter the passageways and travel along the passageways to their outlet outside the container. In this way the material from which the device is made is used to form an integral outlet to the device. This is shown diagrammatically in Figures 5 and 6. Here a container having the general configuration shown in Figure 1 is formed from a sheet of corrugated material so as to have a front wall 10 and a rear wall 1 liThe front wall 10 of the container 1 is partially cut through internally along the apex of the base of the container and the wall is bent along the line of the cut to expose the reeds or flutes of the corrugated material.The material of the wall is then cut externally parallel to, but below, e.g. 1 to 1 Ocms below, the first cut and folded back on itself to form the rear wall 11 of the container. The second cut again exposes the reeds or flutes within the material, but not on an external surface, so that the reeds or flutes form bores extending from within the container to outside the container. Material can flow through the bores as shown arrowed in Figure 5 during operation of the device. If desired the rear wall 11 can be cut along a line opposed to the cut in wall 10 and the wall 11 folded along the cut to expose a double row of bores as shown in Figure 6.

Where the outlet to the container is formed from the reeds or flutes of a corrugated material, the corrugated material can be formed as a coil of material as shown in Figure 7 rather than as a sheet.

Accordingly, from another aspect the present invention provides a container adapted to receive a particulate material and provided with an outlet having a plurality of substantially parallel elongated bores having their inlets adapted to receive particles from the container and having their outlets adapted to discharge material outside the container characterised in that the bores are provided by the internal passageways within a corrugated member.

The term corrugated member is used herein to denote a member having two external planar members substantially parallel to one another and being linked by a series of transverse partitions whereby passageways (or flutes) are formed bounded by adjacent transverse partitions and by the planar members. The partitions can be simple walls linking the two planar members (so as to form a series of parallel squared or trapezoidal cross section passageways) or can be formed by sandwiching a corrugated sheet between the two planar members, the corrugations having any suitable wave form, e.g. a sinusoidal, square or saw tooth wave form. An example of the former type of partition is the extruded plastics material sold under the trade name of Correx; and corrugated cardboard is an example of the second type of partition.

Where the container is to be formed from a corrugated material, this is conveniently done by cutting out a blank of suitable shape having the necessary cuts and folding lines and forming the container as a unitary construction by folding and fixing the blank. Thus, for example a container having the configuration shown in Figure 1 can be formed from a blank as shown in Figure 8.

The blank comprises three approximately equal rectangular panels 31,32 and 33 linked in tandem to one another. The first panel 31 forming the lid to the container, the second panel 32 linked thereto by a hinge line, e.g. by a score zone 34 and forming the front wall 10 to the container and the third panel 33 forming the back wall 11 of the container linked to the second panel 32 via a section 35 having an upper cut line 36 adjacent panel 32 and a lower cut line 37 therein adjacent to panel 33. The cut lines expose the flutes of the corrugated material from which the blank is made on opposite faces of the blank.

Panel 32 carries triangular side pieces 38 and 39 linked to panel 32 by hinge lines, e.g. scores lines 40, and having their apexes at cut line 36.

The container is assembled by folding in side pieces 37 and 38 so that they are generally perpendicular to panel 32. The section 35 is folded back on panel 33 at cut line 37, thus exposing the flutes of the corrugated material.

Panel 33 is then attached to the free hypotenuse of the side pieces 38 and 30. This partially folds section 35 back on panel 32 to expose the flutes of the corrugated material along cut line 36. Panel 31 is then folded down onto the free ends of panel 33 and side pieces 38 and 39 along score zone 34 to form the hinged lid to the triangular section container formed by panels 32 and 33 and sides 38 and 39.

The assembled container is held in place by any suitable means, e.g. staples or adhesive between section 35 and panel 33 and elsewhere. However it is preferred to provide panel 31 and side pieces 38 and 39 with suitable lugs which engage with corresponding slots in panel 33 as shown in Figure 8 or vice versa. The lugs on the side pieces 38 and 39 can be elongated as shown in Figure 8 to provide feet upon which the container can rest as shown in Figure 9. Also as shown dotted in Figure 8 and in Figure 9, the shorter free side of side pieces 38 and 39 can be extended to form handle pieces by which the container can be carried.

The invention therefore also provides a blank made from a sheet of corrugated material and from which a container of the invention can be formed, which blank comprises three approximately equal rectangular panels linked in tandem; the first panel being linked to the second panel along a hinge line, the second panel being linked to the third panel via a smaller generally rectangular section having a transverse cut line through its upper face adjacent the second panel and another transverse cut line spaced from but generally parallel to the first cut line through its under face adjacent the third panel whereby the flutes of the corrugated material are adapted to be exposed upon flexing the blank along the cut lines; the second panel carrying at each side thereof generally triangular side pieces linked thereto by hinge lines and with their apexes directed towards the third panel.

The rate of flow of material through the outlet bores will vary with the dimensions of the bore.

Surprisingly we have found that by suitable selection of the bore dimensions it is possible to control the flow of particles through the bores so that flow will only occur when the device is shaken to give a component of motion generally parallel to the axis of the bores, but not when the device is not so shaken. We believe that this condition is achieved when there is bridging of the particles at the inlet to or within the bores and that the flow of material through the bores is maintained by the shaking which inhibits the formation of a stable bridge. There is a complex inter-relationship between the bore diameterthe diameter of the particles flowing in the bore and the frictional values between the particles and between the particles and the walls of the bores.

The optimum dimensions of bore required to cause bridging with a given particle can be readily determined by simple trial and error variation of the length and diameter of the bores. However, we prefer that the effective bore diameter is from 1.5 to 5 times the mean diameter of the particles and that the length of the bore is from 5 to 20 times the effective diameter of the bore.

The invention also provides a device of the invention wherein the container contains a particulate solid and the bores have an effective internal diameter which is from 1.5 to 5 times the mean diameter of the particles.

The term effective diameter denotes the diameter of the largest circle which can be contained within the cross-section of-the bore.

By using the formation of bridges of particles to interrupt flow of material through the bores, it is possible to do without the flow control means hitherto required with other forms of dispenser.

Actuation of the device is achieved by shaking, oscillating, pivotting or otherwise moving the device in a motion which has a component direction generally parallel to the line of the passageways. This provides a very simple and effective means for dispensing particles from the device and enables one to construct a device which has no moving parts, which is simple and robust and which is simple to operate.

The invention thus also provides a method for dispensing particles from a device of the invention characterised in that the device is reciprocated, oscillated, pivotted or otherwise moved with a motion which has a component direction generally parallel to the axis of the bores so as to inhibit formation of bridges of the particles adjacent to or within the bores and in that movement is halted when it is desired to cease dispensing of the particles.

The device of the invention finds use with a wide range of material, e.g. for dispensing seeds, fertilizers, peat granules and other horticultural products. Typically the particles to be dispensed have a particle size in the range 0.1 to 5 mms, preferably 0.2 to 2 mms with a mean size of 0.5 to 1.5 mms. For such particles the bores in the outlet should have a diameter of from 3 to 5 mms.

Claims (9)

1. A container adapted to receive a particulate material and provided with an outlet having a plurality of substantially parallel elongated bores having their inlets adapted to receive particles from the container and having their outlets adapted to discharge material outside the container characterised in that the dimensions of the bores are selected so that bridging of particles across the bores occurs in the absence of movement of the container in a motion having a component of direction substantially along the axis of the bores.

2. A container adapted to receive a particulate material and provided with an outlet having a plurality of substantially parallel elongated bores having their inlets adapted to receive particles from the container and having their outlets adapted to discharge material outside the container characterised in that the bores are provided by the internal passageways within a corrugated material.

3. A blank made from a sheet of corrugated material and from which a container as claimed in either of claims 1 or 2 can be formed, which blank comprises three approximately equal rectangular panels linked in tandem; the first panel being linked to the second panel along a hinge line, the second panel being linked to the third panel via a smaller generally rectangular section having a transverse cut line through its upper face adjacent the second panel and another transverse cut line spaced from but generally parallel to the first cut line through its under face adjacent the third panel whereby the flutes of the corrugated material are adapted to be exposed upon flexing the blank along the cut lines; the second panel carrying at each side thereof generally triangular side pieces linked thereto by hinge lines and with their apexes directed towards the third panel.

4. A container as claimed in either of claims 1 or 2 wherein the container has a generally triangular cross-section and the outlet is located at the basal apex of the container.

5. A container as claimed in any one of claims 1,2 or 4 wherein the container and the outlet are integral with one another and are formed from a corrugated material having squared cross-section passageways therethrough.

6. A container as claimed in any one of claims 1,2 4 or 5 wherein the outlet bores have a -diameteroffrom 3 to 5 mms.

7. A container or blank therefor as claimed in any one of the preceding claims substantially as hereinbefore described with respect to any one of the accompanying Figures.

8. A container as claimed in any one of claims 1,2, 4, 5, 6 or 7 containing a particulate material having a particle size in the range 0.1 to 5 mms.

9. A method for dispensing particles from a container as-claimed in claim 1 characterised in that the device is reciprocated, oscillated, pivotted or otherwise moved with a motion which has a component direction generally parallel to the axis of the bores so as to inhibit formation of bridges of the particles adjacent to or within the bores and in that movement is halted when it is desired to cease dispensing of the particles.