GB2094184A - Applying granules to building tiles - Google Patents

Abstract

In the manufacture of building tiles (2) having a partially granular surface of which a portion is not granulated, masking devices in the form of bucket-shaped containers (6) are used to prevent granular material from being applied to the said portion of the tile surface during the granulating operation. The containers (6) are located in spaced relationship around an endless chain system (3, 5) which is arranged to cause the closed lower end of the container (6) to engage the said portion of the tile surface at a granulating station (G) and subsequently to cause the container (6) to be inverted above a granular material supply (9), whereby any excess material, which would otherwise be applied to the said portion but is received in the container (6), is recycled for re-use. A tile transport system includes lugs (8) which guide consecutive tiles to the station (G) and move in synchronism with the containers (6). A feed conveyor (1) for the tiles (2) moves in the same direction as both the masks and the lugs but at a slower speed, whereby randomly positioned tiles (2) on the conveyor (1) are separated from each other before reaching the station (G). <IMAGE>

Description

SPECIFICATION Method and apparatus for manufacturing building tiles with partially granulated surfaces Description This invention relates to building tiles, such as concrete roof tiles with granular surfaces, wherein a predetermined portion of an otherwise totally granular tile surface is not granulated during manufacture of the tile. The invention is particularly related to a method and an apparatus for manufacturing a building tile having a partially granular surface.

An advantage associated with tiles having surface area portions which are not granular is that, in use of the tiles in adverse weather conditions, such as in heavy rain and strong winds, the non-granular and generally smooth portions of the imbricated tiles substantially reduce or even prevent the possibility of the ingress of water between the tiles. Additional iy, this type of tile can be used to construct roofs whose pitches are lower than those of roofs constructed from tiles with totally granular surfaces, in view of the lack of or substantial reduction in the ingress of water between the imbricated tiles which are manufactured in accordance with the invention.

Therefore, in accordance with one aspect of the invention, there is provided a method of manufacturing a building tile having a partially granular surface of which a predetermined portion is not granulated during the granulating operation, wherein masking means is used to prevent a granular or particulate material from being applied to said predetermined portion of the tile surface during the granulating operation, said masking means being arranged to receive the excess granular or particulate material, which would otherwise be applied to said predetermined surface portion, and to return the excess material to a supply from which the granular or particulate material is applied to the remaining portion of the tile surface during the granulating operation.

In accordance with a second aspect of the invention, there is provided apparatus for manufacturing a building tile having a partially granular surface of which a predetermined portion is not granulated, the apparatus including masking means for preventing a granular or particulate material from being applied to said predetermined portion of the tile surface, said masking means being arranged to receive excess granular or particulate material, which would otherwise be applied to said predetermined surface portion, and to return the excess material to a supply which is associated with the apparatus and from which the material is applied to the remaining portion of the tile surface.

Preferably, said masking means is in the form of a bucket-type container which, during the masking operation, has its open end uppermost, with its lower end engaging the tile surface to provide the masking action. After the excess material has been received in the bucket-type container, the container can be inverted such that the material falls into the supply which is located above the position where the material is applied to the remaining portion of the following tiles.

Advantageously, the tiles, to whose surfaces the granular or particulate material is to be applied, are fed to a granulating station upon a conveyor with which is associated indexing means for moving consecutive tiles to the granulating station in coordination with the bucket-type masking means.

In a preferred embodiment of the invention, the indexing means and masking means are carried on separate endless, driven belts or chains whose respective speeds can be adjusted to provide coordination between said means at the granulating station. A rotating brush may be associated with the bucket-type masking means, such that the closed lower end thereof can be brushed clean between each masking step at the granulating station.In orderthatthe invention may be more fully understood, a preferred embodiment of apparatus in accordance therewith, for performing the inventive method, will now be described by way of example and with reference to the accompanying drawings in which: Figure lisa side elevation of the general form of the apparatus; Figure 2 is a diagramatic, side elevation of the more important working components of the apparatus shown in Figure 1; Figure 3 is a diagramatic side elevation of the transmission drives for the components shown in Figure 2; Figure 4 is a partial plan view of the drives shown in Figure 3; and Figure 5 is a perspective view of a bucket-type container constituting the masking means of the apparatus shown in the previous Figures.

Referring now to the Figures of the drawings, apparatus for manufacturing a concrete tile having a partially granular surface comprises a feed conveyor indicated generally at 1 which feeds tiles 2 to a granulating station Gin the direction of the arrow A.

Two chain drive systems 3,4 are driven at the same linear speed, the first chain system 3 comprising two parallel driven chains 5 of which only one is shown.

Spaced along the length of these chains 5 is a series of bucket-type containers 6 which constitute masks, as will be described below. The second chain system 4 comprises an endless, driven chain 7 which, as indicated above, is moving at the same linear speed as that of the chains 5. This chain 7, whose linear speed as that of the chains 5. This chain 7, whose linear speed is greater than that of the feed conveyor 1, has indexing lugs 8 for engaging behind each tile 2 as it moves along the conveyor 1, whereby the tiles are separated by a predetermined distance and guided to the granulating station G.The guiding movement of the indexing lugs 8 is in synchronism with the movement of the masking containers 6, such that each respective pair of lugs 8 and containers 6 arrive in a co-ordinated manner at the granulating station G, together with an associated tile 2 whose upper surface is to be partially granulated with a granular or particulate material which is fed under gravity from a material supply 9 located directly above the granulating station G. This material supply 9 can be controlled to allow granular or particulate material to fall under gravity therefrom each time a tile 2 is located at the granulating station G.

At the station G, the lower, closed end of each bucket-type container 6 engages with the upper surface of the associated tile 2, to mask a predetermined portion of of this surface, so that none of the granular or particulate material is applied thereto, whilst the remaining unmasked portion of the upper tile surface has the material applied to it from the supply 9.

After each container 6 has carried out its masking action at the granulating station G it is moved upwardly and subsequently inverted above the material supply 9, so that any excess material which has been received in the container 6 at the granulating station G falls into the supply 9 for subsequent application to a following tile 2.

In operation of the apparatus, as shown in Figure 2, the tiles 2 are fed in a generally random manner along the conveyor 1 until they reach more or less the position indicated at B. Here, the trailing edge of each tile 2 is engaged by a respective indexing lug 8 which then moves the associated tile 2 to the granulating station G at a speed which is greater than that at which the conveyor 1 is moving. As the guided tile 2 reaches the granulating station G, an associated bucket-type container 6 engages its closed lower end with the predetermined portion of the upper surface of the tile 2 to which the granular or particulate material is not to be applied. At this station G, the material is then applied from the supply 9 to the remaining portion of the upper surface of the tile 2.Any excess material, which would otherwise be applied to the predetermined portion of the upper tile surface, falls into the masking container 6 which, on movement upwardly and away from the granulating station G is eventually inverted above the supply 9, such that this excess material falls into this supply for subsequent recirculation.

As shown in Figures 1,3 and 4, the two chain systems 3 and 4 are adjustably driven by an electric motor 10 via respective chain drive wheels 11, 12.

Each of these drive wheels 11, 12 is driven from a main drive wheel 13 associated with the motor 10, the wheel 11 via a belt or chair drive 14. The remaining pair of chain wheels 15, 16 of the chain system 5 and the remaining one chain wheel 17 of the chain system 4 are freeiy rotatable. A belt wheel 18 is also provided for the endless belt conveyor 1, although this wheel is not associated with the drive for that of the chain wheels 11, 12 of the respective systems 3, 4.

The speed of each chain system 3, 12 can be adjusted to regulate the synchronism between the masking containers 6, the indexing lugs 8 and/or the movement of the tiles 2 along the conveyor 1.

As shown in Figure 1, the apparatus is provided with a rotating brush 19 which cleans the inverted containers 6 as they move between the chain wheels 15 and 11 of the chain system 3. This rotating brush 19 can also be driven from the electric motor 10.

Adjustment means 20, 21 are also shown in Figure 1 for adjusting synchronism between the two chain systems 3, 4.

Referring now to Figure 5 of the drawings, here there is shown a perspective view of a typical form of bucket-type container 6 whose closed lower end engages, at the granulating station G with the predetermined portion of the upper surface of each tile 2, to which granular or particulate material is not.

to be applied. In this particular case two planar portions 22 of the closed end of the masking container 6 engage with the upper tile surface, with the container moving in the direction of the arrows C. The other underside portions 23, 24 of the closed end of the container 6 are generally concave, although this particular shape, in combination with the two planar portions 22, is sufficient to form the necessary masking action.

In the particular embodiment of apparatus in accordance with the invention described above, the chain system 3 has eight associated bucket-type masking containers 6, although it will be appreciated that any desired number may be used. Similarly, the appropriate number of indexing lugs 8 can also be provided, as long as there is synchronism between these lugs 8 and the associated containers 6.

Claims (17)

1. A method of manufacturing a building tile having a partially granular surface of which a predetermined portion is not granulated during the granulating operation, wherein masking means is used to prevent a granular or particulate material from being applied to said predetermined portion of the tile surface during the granulating operation, said masking means being arranged to receive the excess granular or particulate material, which would otherwise be applied to said predetermined surface portion, and to return the excess material to a supply from which the granular or particulate material is applied to the remaining portion of the tile surface during the granulating operation.

2. A method according to claim 1, wherein said masking means is provided by a plurality of buckettype containers which are spaced along an endless, driven chain or belt, the closed end of each container engaging the predetermined portion of the tiled surface during the granulating operation, with the open end of the container uppermost.

3. A method according to claim 2, wherein, after the granulating operation, each bucket-type container is inverted, such that excess granular or particulate material, which was received in the container during the granulating operation, is returned to the material supply for subsequent re-use.

4. A method according to claim 2 or 3, wherein consecutive tiles are guided to the station where the granulating operation is carried out by means of indexing means which move in synchronism with the bucket-type containers.

5. A method according to claim 4 wherein said indexing means comprises a plurality of lugs spaced about an endless driven belt or chain.

6. A method according to claim 5, wherein the linear speed of the belt or chain carrying the indexing lugs is varied to regulate the synchronism between the lugs and the bucket-type masking containers.

7. A method according to any preceeding claim, wherein said masking means is cleaned, preferably with a rotatable brush, between each respective granulating operation.

8. A method of manufacturing a concrete building tile having a partially granular surface, substantially as hereinbefore described with reference to the accompanying drawings.

9. An apparatus for manufacturing a building tile having a partially granular surface of which a predetermined portion is not granulated, the apparatus including masking means for preventing a granular or particulate material from being applied to said predetermined portion of the tile surface, said masking means being arranged to receive excess granular or particulate material, which would otherwise be applied to said predetermined surface portion, and to return the excess material to a supply which is associated with the apparatus and from which the material is applied to the remaining portion of the tile surface.

10. An apparatus according to claim 9, wherein said masking means comprises a plurality of bucketshaped containers spaced along an endless driven belt or chain and arranged such that the closed end of each container engages a predetermined portion of the surface of a respective tile, whereby no granular or particulate material is applied thereto during the granulating operation.

11. An apparatus according to claim 9 or 10 including indexing means arranged to guide each consecutive tile to the granulating station and to move in synchronism with said masking means.

12. An apparatus according to claim 11, wherein said indexing means comprises a plurality of indexing lugs spaced around an endless driven belt or chain.

13. An apparatus according to any of claims 9 to 12, wherein the linear speed of said masking means, said indexing means and/or a feed conveyor for the tiles is adjustable.

14. An apparatus according to any of claims 9 to 13 including a rotatable brush arranged to clean said masking means between respective granulating operations at the granulating station.

15. An apparatus for manufacturing a concrete building tile having a partially granular surface substantially as hereinbefore described with reference to the accompanying drawings.

16. A concrete building tile when made by a method according to any of claims 1 to 8.

17. A concrete building tile when manufactured by an apparatus according to any of claims 9 to 15.