GB2195114A

GB2195114A - A container for supplying granular or particulate material

Info

Publication number: GB2195114A
Application number: GB08622694A
Authority: GB
Inventors: Rodney John Lockyer
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-09-20
Filing date: 1986-09-20
Publication date: 1988-03-30
Anticipated expiration: 2006-09-20
Also published as: GB8622694D0; GB2195114B

Abstract

A container for supplying material such as sand, comprises an outer container wall (10) within which a cup-shaped element (18) is mounted at the bottom of the container, the rim of element (18) being connected to wall (10) by an annular wall (16), a shield (20) also being mounted within the container above said cup (18) and wall (16), the shield being aperatured to allow material to fill the cup, from which it is delivered under a pressure head less than the pressure head of the material in the container. In the embodiment of Fig. 4 the shield (38) is only slightly larger than the cup (18), and in the embodiment of Fig. 5, (not shown) the cup (42) is integral with the shield, which forms a cap for the cup, and is rotatable relative thereto to open or close aperature (48). The cup has a cleaning opening at its base. <IMAGE>

Description

SPECIFICATION Controlled delivery container Field of the invention This invention relates to a container which provides for controlled delivery of granular, particulate or like material, and in particular to a container for delivering said material to an outlet point at the base of the container under a head of pressure which does not exceed a predetermined value less than the head of pressure corresponding to the height of the container.

Background to the invention There exist various situations wherein a container capable of holding a substantial volume and weight of material is required to deliver material as aforesaid to a bottom exit under a pressure substantially less than the head of pressure which arises when the container is full or at least filled above a given level.

A particular example of such a situation, to which the present invention is especially applicable, is a container for dry, fine sand for use in sand blasting. For the purpose of sand blasting, especially for small users, a power unit is known which is connectable to a water tap to deliver water under pressure through an outlet wand having a trigger control and downstream thereof a junction piece followed by a nozzle. The junction piece has an inlet connected to a hose through which sand can be sucked, into the water stream passing through the wand, due to the Venturi effect.

This is enabled simply by pushing the free end of the hose into a bag of sand. However, it has been found that the bag of sand must be of a carefully controlled size which does not create an excessive pressure head of sand at the entrance to the hose, because if such an excess pressure head exists sand is sucked into the junction piece and wand at an excessive rate which creates ciogging and blockages. On the other hand, the controlled size bag which avoids this disadvantageous effect is relatively small and is soon emptied. This means that the bags of sand must be relatively frequently replaced, which can be a severe disadvantage when major sand blasting tasks are undertaken in difficult situations, for example on the walls and/or roof of a house.

It is an object of the present invention to provide a controlled delivery container which, amongst other possible usages, provides a solution to the above-described problem of sand delivery for sand blasting.

The invention According to the invention, there is provided a container for delivering granular, particulate or like material to an outlet point at the base of the container under a head of pressure which does not exceed a predetermined value less than the head of pressure corresponding to the height of the container, comprising an outer container wall, a cup-shaped element at the bottom of the container, the outlet point being at the bottom of the cup, a closure wall extending between the periphery of the top of the cup and the outer wall, a shield member above the open top of the cup, said shield member defining aperture means through which material can flow from above the shield member to fill the cup under said pressure head not exceeding the predetermined amount, and means enabling loading of the container above the level of the shield member, said closure wall and/or shield member acting to support the head of material generally above the level of the aperture means.

In the field of sand blasting, as heretofore described, the cup at the bottom of the container preferably has dimensions making it generally equivalent to the controlled size bag previously employed. However, the container itself is capable of holding a much larger sand supply, constituting a reserve from which the cup is kept full without delivering an excessive pressure head at the bottom of the cup.

For sand blasting, the container wall preferably has an aperture, through which the sand hose extends into the container, terminating with a rigid end piece which extends downwardly into the cup with its open end close to the bottom thereof. A resilient washer or bung may seal the container wall aperture around the hose.

In one embodiment, the shield member is an apertured wall having its periphery fixed to the container wall at a spacing above the closure wall associated with the cup. This apertured wall is preferably domed, apex uppermost, and is apertured adjacent its periphery, close to the container wall. In use sand, for example, can fill the container, including the cup, up to the level of the apertures, but will not generally flow to fill the void beneath the dome above the level of the apertures.

In another embodiment, the shield member is a cap located just above or on top of the cup to define the aperture means. Such a cap may possibly be carried by the rigid end piece of the sand hose in the case of sand blasting.

Alternatively, the cup and cap may be formed as a unit. In such a unit the top of the cup or the cap may be apertured and the cap rotata ble relatively to the cup to enable the apertures to be opened or closed. At the bottom of the cup, a window closable by an access ring may be provided, whereby rotation of the ring enables the window to be exposed for access to the bottom of the cup for cleaning purposes.

The container wall preferably has an open top closable by a lid removable to enable filling. If desired, container wall sections may be provided which will fit in piace of the lid, and in turn receive the lid on top, for extending the height of the container in order to increase its capacity.

in fields other than sand blasting, the bottom of the cup may have a delivery port connected thereto, thereby to enable granular, particulate or like material to be fed to said delivery port at a controlled rate largely independent of the extent to which the container is or remains filled.

Description of drawings The container in accordance with the invention will now be exemplified with reference to the accompanying drawings, in which: Figure 1 shows the container in elevation, partly cross-sectioned; Figure 2 is a plan view of a domed shield member; Figure 3 is a transverse cross-section through the container, below the level of the shield member; Figure 4 shows a modified arrangement of the cup and shield members; Figure 5 shows another modification of said members on an enlarged scale; Figure 6 shows a detail of the shield member of Figure 5; and Figure 7 shows a power suction tool for sand blasting with which the container may be used.

Description of embodiments The container of Figure 1, intended for use with a known power suction tool for sand blasting shown in Figure 7, has an outer wall 10 which is extended in height by an optional extension piece 12 and is closed at tke top by a lid 14 removable to enable filling with fine, dry sand.

The bottom region of the container is closed off by a somewhat conical closure wall 16 supporting a central cup 18. Above the closure wall 16 the container is spanned by a domed shield 20, apertured at 22 near its periphery close to the container wall. A sand hose 24 (see also Figure 7) extends through a bung 26 in the wall of the container, terminating in a rigid end piece 28 which extends downwardly into the cup 18 with its open end, carrying a flow restrictor 30, close to the bottom of the cup.

In use, when the container is filled with sand, for example up to the level 32, flow occurs into the lower region through the apertures 22 to fill said lower region, including the cup 18, up to a level just above that indicated at 34. Flow into the lower region then ceases if sand is not used, because the apertures are blocked by the rising sand level. Flow recommences when sand is used, which occurs during sand blasting when sand is sucked out through the sand hose 24. At the outlet point constituted by the open end of the sand hose, the head of pressure developed by the sand is limited to the height of sand below the shield 20, and therefore does not exceed a predetermined value. Emptying can occur, however, past the level 36 which is the lowest level to be expected during normal usage with a full container, to a level partway down the cup.

Further details will be clear from Figures 2 and 3.

Figure 4 shows a modified embodiment when the shield member is in the form of a cap 38 mounted just above the cup 18 to define apertures 40.

Figure 5 shows another modification in which the cup 42 and cap 44 are formed as a unit wherein the cap is rotatable relative to the cup, as by means of gear and pinion 46, to open or close apertures 48. The cup 42 has a window 50 at the bottom, accessible by rotation of a normally closed access ring 52 to enable the bottom of the cup to be cleaned out. Figure 6 shows the cap 44 in more detail.

For completeness, Figure 7 shows the power tool with which the aforedescribed container is intended to be used in application to sand blasting. It comprises a power unit 54 having a water inlet hose 56 for connection to a tap, and a water outlet hose or wand 58 for delivering water under pressure, under control of trigger unit 60, through a junction piece 62 to a nozzle 64. The aforementioned sand hose 24 connects with the junction piece 62, whereat suction created by the Venturi effect of the high pressure water flow causes sand to be drawn through the hose 24 into the water stream. The controlled delivery container of this invention prevents the junction piece and wand from becoming clogged with sand due to excess supply thereof through the sand hose.

Various modifications of the described and illustrated embodiments of container are pos sible within the scope of the invention, especially for fields of application other than sand blasting.

Claims

1. A container for delivering granular, particulate or like material to an outlet point at the base of the container under a head of pressure which does not exceed a predetermined value less than the head of pressure corresponding to the height of the container, comprising an outer container wall, a cup-shaped element at the bottom of the container, the outlet point being at the bottom of the cup, a closure wall extending between the periphery of the top of the cup and the outer wall, a shield member above the open top of the cup, said shield member defining aperture means through which material can flow from above the shield member to fill the cup under said pressure head not exceeding the predetermined amount, and means enabling loading of the container above the level of the shield member, said closure wall and/or shield mem ber acting to support the head of material generally above the level of the aperture means.

2. A container according to claim 1, wherein the cup at the bottom of the container has dimensions making it generally equivalent to a predetermined controlled size bag.

3. A container according to claim 2, wherein the container itself is capable of holding a much larger material supply, than said equivalent to said bag, constituting a reserve from which the cup is kept full without delivering an excessive pressure head at the bottom of the cup.

4. A container according to claim 1 or claim 2 or claim 3, wherein the container wall has an aperture, through which a hose extends into the container, terminating with a rigid end piece which extends downwardly into the cup with its open end close to the bottom thereof, a resilient washer or bung seaiing the container wall aperture around the hose.

5. A container according to any of claims 1 to 4, wherein the shield member is an apertured wall having its periphery fixed to the container wall at a spacing above the closure wall associated with the cup.

6. A container according to claim 5, wherein the apertured wall is domed, apex uppermost, and is apertured adjacent its periphery, close to the container wall, whereby in use material can fill the container, including the cup, up to the level of the apertures, but will not generally flow to fill the void beneath the dome above the level of the apertures.

7. A container according to any of claims 1 to 4, wherein the shield member is a cap located just above or on top of the cup to define the aperture means.

8. A container according to claim 7, wherein the cup and cap are formed as a unit.

9. A container according to claim 8 wherein, in said unit, the top of the cup or the cap is apertured and the cap rotatable relatively to the cup to enable the apertures to be opened or closed, whilst at the bottom of the cup, a window closable by an access ring is provided, whereby rotation of the ring enables the window to be exposed for access to the bottom of the cup for cleaning purposes.

10. A container according to any of claims 1 to 9, wherein the container wall has an open top closable by a lid removabie to ena ble filling, container wall sections being provided which will fit in place of the lid, and in turn receive the lid on top, for extending the height of the container in order to increase its capacity.

11. A controlled delivery container substantially as hereinbefore described with reference to the accompanying drawings.