GB2506011A

GB2506011A - Carrier assembly

Info

Publication number: GB2506011A
Application number: GB1313470.5A
Authority: GB
Inventors: Terence Butlin
Original assignee: Eco Filters Ltd
Current assignee: Eco Filters Ltd
Priority date: 2012-08-09
Filing date: 2013-07-29
Publication date: 2014-03-19
Anticipated expiration: 2033-07-29
Also published as: WO2014023946A1; EP2882510B1; EP2882578B1; GB201311932D0; EP2882510A1; GB201313470D0; WO2014023945A1; GB2504848B; GB2504848A; GB2506011B; EP2882578A1

Abstract

A carrier assembly 4 for a cementitious press mould of the type used to fabricate paving slabs or kerbs comprises a carrier support 8 and a removeably engageable carrier insert 54. The carrier support 8 comprises a frame adapted to receive and support the carrier insert which may comprise a support ledge incorporating a plurality of drainage apertures a plurality of corner portions and support members (102 in figure 8). The carrier insert comprising a plurality of perforations 20 which may form a pattern on its surface that engages with a filter section 6. A filter for the carrier may comprise a frame 32 or outer portions (82-88 figure 6) receiving frame strips (74-80) received in channels (94) in the sides of the insert.

Description

CARRIER ASSEMBLY

This invention relates to a carrier assembly for use in a cementitious press mould such as a wet concrete, hermetic or semi-dry mix press mould.

A known cementitious press mould comprises a mould cavity having a closed base and side walls. A metered amount of cementitious mix is placed into the mould cavity and a movable press head is then moved towards the closed base to apply a high compressive io pressure on to the cementitious mix.

The press head comprises a die head having a head plate that comes into contact with the mixture contained in the mould. The head plate is of a shape and size that corresponds to the cross-sectional shape and size of the mould cavity.

The base of the press mould comprises a bottom former that has a shape and size that corresponds to the cross-sectional shape and size of the mould cavity.

Various actions within the cementitious mix occur when the compressive pressure is applied. For example, in a wet concrete press mould, a wet concrete mix is compacted, it is shaped to the shape of the mould, and excess water is squeezed out of the wet mixture.

A result of these actions is the formation of a moulded product, such as a paving slab or

kerb, for example.

In a wet concrete press mould, excess water is conducted away from the die head under the assistance of a vacuum, created in the die head and through the bottom former of the mould cavity. It is known that the action of the press head causes the majority of the excess water to be expelled via the die head.

It has been found that during the moulding process, the compressive forces applied by the press head to the concrete mix cause a large proportion of the excess fluid to flow toward the edges of the die head, resulting in high pressure and frictional forces acting on the edges of the die head.

In a hermetic press mould, a cementitious mix designed specifically for the press mould is placed in the mould cavity. The cementitious mix usually consists of a face and back mix.

The face mix normally comprises expensive aggregates with a high cement content and is generally very wet when discharged into the mould. The back mix is a weak semi-dry cement mix, and is placed on top of the face mix within the cavity.

Due to the fact that a hermetic press mould comprises a sealed base, cement enriched io water from the face mix is forced through the back mix when under pressure from the press head.

In a semi-dry press mould, a semi dry mix having a higher cement content, and slightly wetter consistency than the back mix of a hermetic press mould, is placed in the mould cavity. The water/cement ratio of the mix is such that on compaction from either pressure or vibration, the mix forms a solid mass to the required strength.

It is also known to provide filters which cover the closed base and the moveable head plate in order to provide a release for removal of the moulded product from the mould and also to assist in preventing particulate material (such as cement particles and aggregate fines) from exiting the mould via the closed bottom or the head plate.

It is known to form perforations in both the bottom former and the die head in order to assist the flow of excess fluid out of the mould. The bottom former and the die head may each be described as carriers. In known cementitious press moulds, one or both carriers may comprise a carrier plate. When the carrier plate comprises the bottom former, the plate may comprise perforations arranged in a particular pattern in order to produce a variety of patterns on products formed by the press mould.

In such known press moulds, the pattern produced on a product is produced by the filter.

This is because it is not possible to change the pattern of the perforations formed on the bottom former, since the bottom former is a permanent part of the press mould. The only way to change the pattern on a product formed by the press mould is therefore to change filters so that the pattern is produced on the product by means of the filter, rather than the former.

It is therefore necessary to stock filters appropriate to each type of product that will be produced using the press mould.

According to a first aspect of the present invention there is provided a carrier assembly for a cementitious press mould, the carrier assembly comprising a carrier support and a carrier insert comprising a first surface and an opposite second surface removeably engageable with the carrier support, wherein the carrier support comprises a frame adapted to receive and support the carrier insert, and the carrier insert comprises a plurality of perforations and is adapted to engage with, and be supported by the carrier io frame.

The carrier insert may have a pattern formed on its surface. The pattern may be formed from one or more of the plurality of perforations, or may be formed by indentions or other apertures for example.

The drainage apertures may thus form part of the pattern, or they may comprise smaller holes that are masked by the pattern.

By means of the present invention, it is possible to have a carrier insert with a particular pattern appropriate to a particular product. When it is desired to produce a different product having a different pattern, it is necessary simply to remove the carrier insert and to replace it with a second insert having a pattern appropriate for that product.

In this way, it is possible to readily create a different pattern by inserting an appropriate carrier insert into the carrier support.

The carrier assembly may comprise a bottom former. In such embodiments, the carrier support comprises a bottom former support, and the carrier insert comprises a bottom former insert. The ability to create a pattern on a product being formed in the mould is particularly useful when the carrier assembly is a bottom former assembly.

Because the carrier support comprises a frame which supports the carrier insert, the carrier insert makes contact with the carrier support around edge portions of the carrier insert only. This means that by suitably dimensioning the frame relative to the carrier insert, most of a central portion of the carrier insert will be open, and not in contact with the carrier support.

This in turn means that it is possible for a fluid to drain freely away through apertures formed in the carrier insert.

The present invention thus facilitates drainage of fluids during the moulding process.

This is in contrast to known press moulds comprising a carrier insert supported by a carrier plate. In such known press moulds, drainage holes must be formed in the carrier plate as well as in the carrier insert. However, it can be difficult, if not impossible to ensure alignment of the drainage holes in the carrier plate with those in the carrier insert.

This will be a particular problem in moulds where the carrier insert is readily exchangeable with other inserts in order to ensure that an appropriate pattern is produced on a product being formed by the mould. This is because every time an insert is placed on the carrier plate, it is necessary to position the insert to attempt to align the apertures in the insert with those in the carrier plate.

The carrier insert and the carrier support may be formed from any suitable material such as steel, wood or a plastics material. Any material that is capable of withstanding the forces exerted during the pressing process could be used.

In some embodiments of the invention, the carrier frame may comprise a plurality of corner portions.

The carrier frame may be of any convenient shape, and may, for example comprise four corner portions.

The corner portions may be detachable from the carrier frame. This means that the corner portions may be machined separately from the remainder of the frame. This in turn means that it is possible to produce substantially square corners.

In some embodiments, the carrier frame may have some other shape, not having any corner portions. For example, the carrier frame may be substantially oval or circular in shape.

The carrier support may comprise an additional support member. In some embodiments of the invention it may be necessary to have an additional support member to support the carrier insert, in addition to the carrier frame.

The carrier frame may be formed from a single piece of material, although in other embodiments it may be formed from a plurality of frame components.

It may be more economical to form the carrier frame from a plurality of the frame components since it is often possible to use less material if the carrier frame is formed in this way. This is in contrast to when the carrier frame is formed from a single piece of material, when it may be necessary to machine the frame from a large piece of material, most of which will not be used for the frame. This can wasteful and time consuming.

The frame components may be joined together by any suitable means, for example by means of adhesive, through the use of nails, screws or bolts, or means of welding or bonding, for example.

The carrier support may comprise a ledge formed in the carrier frame, the ledge comprising a support surface adapted to receive and support the carrier insert.

In such embodiments, the carrier insert is adapted to make contact with the ledge along a peripheral portion of the second surface thereof.

The ledge may comprise a plurality of drainage apertures. These drainage apertures enable fluid to drain away during use of the mould, rather than accumulating and creating a well or wet area around the edge of the former assembly.

The ledge may comprise a plurality of ledge portions. The ledge portions may be spaced apart from one another. In one embodiment, the ledge portions are substantially triangular in shape and are positioned at corners of the frame. In other embodiments however the ledge portions may be positioned at different parts of the frame.

In some embodiments, the additional support member comprises a bar extending across the carrier frame.

In some embodiment of the invention there may be more than one additional carrier support member.

In embodiments of the invention comprising one or more additional support members, the one or more additional support members may comprise a plurality of drainage apertures.

In other words, the carrier support may comprise a plurality of drainage apertures allowing drainage of fluids during use of the mould.

The carrier support may comprise a first surface and second opposite surface.

In some embodiments, the carrier insert may comprise a recess extending around the second surface to form a recessed carrier insert.

In use, the recessed carrier insert is engageable with the ledge of the carrier support such that the recess of the insert engages with the ledge. This means that the insert is held in position such that the second surface is substantially flush with the second surface of the carrier support. In other words, the carrier support and the carrier insert may be positioned at the same level relative to one another during use.

In some embodiments of the invention, the first surface of the carrier insert will extend above the carrier support. This means that, in use, a filter assembly can be secured around the carrier insert which will stand proud of the carrier support.

In such embodiments, the carrier insert may comprise a plurality of channels extending at least partially along edges of the carrier insert.

According to a second aspect of the present invention there is provided a filter assembly comprising a carrier assembly according to the first aspect of the present invention further comprising a filter assembly engageable with the carrier assembly.

Any suitable filter assembly may be used with a carrier assembly of the present invention.

One particularly suitable filter assembly is described in our co-pending application No. GB 1214240.0.

The filter assembly described therein comprises a filter comprising a filter sheet mounted on a filter frame. Such a filter assembly may be directly engageable with the carrier support of the carrier assembly according to embodiments of the invention.

The filter sheet and filter frame may be manufactured to appropriate dimensions to fit a particular carrier support.

The filter sheet may be attached to the filter frame by any convenient means such as by stitching, adhering, bonding through the use of ultrasonic techniques etc. Alternatively, the edges of the filter sheet may be folded around the filter frame and then glued to an underneath surface of the filter frame, for example.

The filter frame may be made from any suitable material, such as a plastics material. In particular, the filter frame may be farmed from polypropylene, fibreglass, carbon fibre, metal or wood, for example.

The filter frame may be farmed from a single piece of material. Alternatively it may be formed from a plurality of frame sections each of which frame sections is engageable with one or more other frame sections to form the filter frame.

In embodiments of the invention in which the carrier insert is raised above the carrier border, the carrier insert may serve as a carrier engagement portion engaging with the filter assembly and holding the filter in place.

The filter frame may be shaped to have an interference fit with the carrier insert. In other embodiments a clip or other retainer may be used to hold the filter frame against the carrier insert.

In some embodiments of the invention, the filter sheet forming the filter comprises frame receiving portions extending around the perimeter of the fabric sheet.

In such embodiments the filter comprises a plurality of separate filter strips, each strip extending along an edge of the filter sheet.

The filter strips may be formed from any particular material and for example may be formed from a plastics material.

The filter strips may be attached to the filter sheet by any convenient means, and may for example be adhesively attached to the filter fabric. The filter strips may be attached to the filter sheet by means of bonding. The bonding may be any type of bonding such as heat bonding or pressure bonding.

Once the filter strips have been attached to the filter sheet, they may be folded so that they are orientated at substantially 90° to the plane in which the sheet of fabric lies.

The carrier insert may have channels formed therein, which channels are shaped to receive the frame strips to thereby hold the filter tautly in position over the carrier insert.

The invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a schematic exploded representation of a filter assembly according to an embodiment of the invention; Figure 2 is a schematic representation showing parts of the carrier support forming the carrier assembly shown in Figure 1; Figure 3 is a schematic representation showing how the carrier insert is positioned within the carrier support shown in Figure 2; Figure 4 is a schematic representation of a filter forming part of a filter assembly according to an embodiment of the invention; Figure 5 is a schematic representation showing how the frame strips of the filter can be positioned for engagement with the carrier insert; Figure 6 is a schematic representation of a carrier insert for use with the filter shown in Figure 4 and comprising channels for receiving the frame strips of the filter; and Figures 7 and 8 are schematic representations of a carrier support according to a further embodiment of the invention.

Turning now to Figure 1, a filter assembly according to an embodiment of the invention is designated generally by the reference numeral 2.

The filter assembly comprises a carrier assembly 4 and a filter 6.

The carrier assembly comprises a carrier support 8 comprising a carrier frame 10.

The carrier frame 10 comprises a support ledge 12 extending around the carrier frame and providing a support surface. The ledge has a plurality of drainage apertures 14 farmed therein. The drainage apertures 14 are through holes that allow fluid to drain away from the carrier assembly during use.

The carrier frame 10 comprises detachable corner portions 16. The corner portions 16 are manufactured separately from the carrier frame 10. This enables the corners to be accurately machined avoids having rounded portions at the corners of the frame.

The carrier assembly further comprises a carrier insert 18 shaped to fit within the carrier frame 10 such that the carrier insert 18 is supported on the ledge 12. The carrier insert 18 is formed with the drainage holes 20 and is also embossed with a pattern that will be transferred to a product during use of the mould.

The drainage holes 20 may either form part of the pattern or may be formed from apertures that are smaller than those used in the pattern and therefore hidden by the pattern. In this embodiment the drainage holes are part of the pattern.

The carrier insert is shaped to engage with the ledge 12 such that it extends above, and stands proud of the carrier frame 10.

The filter assembly 2 comprises a filter sheet 30 and a filter frame 32. The filter sheet 30 may be attached to the filter frame 32 by any convenient means such as by stitching, adhesion, heat bonding, pressure bonding, ultrasonic techniques etc. In use, the filter frame 32 is locatable around the carrier insert 18 that extends above the carrier frame 10.

The carrier frame 10 as shown in Figure 1 may be formed from one sheet of material, with the corner portions 16 being formed separately to the remainder of the carrier frame 10.

Turning now to Figure 2, another carrier frame 40 is illustrated. The carrier frame 40 is made up of separate components 42, 44, 46, and 48 which are joined together in any convenient manner.

Turning now to Figure 3, another embodiment of a carrier assembly according to the present invention is shown, and designated generally by the reference numeral 50. In this embodiment, the carrier assembly comprises a carrier support 52 and a carrier insert 54.

The carrier support 52 is similar to the carrier support 8 shown in Figure 1.

The carrier insert 54 comprises a first portion 56 and a second, recessed portion 58.

io When the carrier insert 54 is located within the carrier support 52, the recessed portion 58 is shaped to fit within the ledge 12 so that when the carrier insert is positioned within the carrier support 52, the recessed portion 58 extends to be level with the carrier support with an underside of the carrier support 52.

A surface 60 of the first portion of the carrier insert is adapted to engage with the ledge 12 thus allowing the carrier insert to be supported by the carrier support 52.

Turning now to Figures 4 to 6, a second embodiment of a filter assembly according to an embodiment of the invention is designated generally by the reference numeral 70. The filter assembly 70 comprises a sheet of filter fabric 72 and frame strips 74, 76, 78 and 80.

The filter sheet comprises outer portions 82, 84, 66 and 88. Each of the outer portions is shaped to receive one of the frame strips 74, 76, 78 and 80. A respective frame strip 74, 76, 78, 80 may be attached to a outer portion 82 to 88, and the frame strips 74 to 80 may then be bent over in the direction as shown by arrows 90.

In such an embodiment the carrier assembly comprises a carrier insert 92, The sides of the insert 92 have been machined to form channels 94 shaped to receive a frame strip once it has been attached to the filter fabric. In such an embodiment the filter may be pulled over the carrier insert with all four of the frame strips 74 to 80 being located in a respective channel 94. This has the effect of creating a taut filter over the face of the carrier insert.

Turning now to Figures 7 and 6, a carrier frame according to another embodiment of the invention is designated generally by the reference numeral 100.

In this embodiment of the invention the carrier support comprises a plurality of ledge portions 102, which in this embodiment are substantially triangular in shape, and are formed in the corners of the frame. The carrier support comprises an additional support member 104 which provides additional support to the carrier insert.

The ledges 102 and the additional support member 104 may comprise a plurality of drainage holes of the type shown in Figure 1 and designated by the reference numeral 12.

In this embodiment, the frame is formed from a plurality of frame members 106.

Claims

CLAIMS1. A carrier assembly for a cementitious press mould, the carrier assembly comprising a carrier support and a carrier insert comprising a first surface and an s opposite second surface removeably engageable with the carrier support, wherein the carrier support comprises a frame adapted to receive and support the carrier insert, and the carrier insert comprises a plurality of perforations and is adapted to engage with, and be supported by the carrier frame.
2. A carrier assembly according to Claim 1 wherein the carrier insert comprises a pattern formed on a surface thereof.
3. A carrier assembly according to any one of the preceding claims wherein the carrier support comprises a bottom former support and the carrier insert comprises a bottom former insert.
4. A carrier assembly according to any one of the preceding claims wherein the carrier frame comprises a plurality of corner portions.
5. A carrier assembly according to any one of the preceding claims comprising an additional support member.
6. A carrier assembly according to any one of the preceding claims wherein the carrier support comprises a ledge formed in the carrier frame, the ledge comprising a support surface adapted to receive and support the carrier insert.
7. A carrier assembly according to Claim 6 wherein the ledge comprises a plurality of drainage apertures.
8. A carrier assembly according to any one of the preceding claims wherein the carrier support comprises a first surface and an opposite second surface.
9. A carrier assembly according to any one of the preceding claims wherein carrier insert comprises a recess extending around the second surface of the insert carrier to form a recessed carrier insert.
10. A filter assembly for a cementitious press mould comprising a carrier assembly according to any one of Claims 1 to 9, further comprising a filter engageable with the carrier insert.
11. A filter assembly according to Claim 10 wherein the filter comprises a filter sheet mounted on a filter frame.
12. A filter assembly according to Claim 11 in which the filter sheet comprises frame receiving portions extending at least partially around the perimeter of the filter sheet.
13. A filter assembly according to Claim 12 wherein the filter comprises a plurality of separate filter strips, each strip extending at least partially along an edge of the filter sheet.
14. A cementitious press mould comprising a filter assembly according to any one of Claims lOto 12.
15. A cementitious press mould comprising a carrier assembly according to any one of Claims ito 9.