GB2181678A

GB2181678A - Treating stone blocks to simulate weathering

Info

Publication number: GB2181678A
Application number: GB08516216A
Authority: GB
Inventors: John Arthur West; Brian David Burns
Original assignee: ECC Quarries Ltd
Current assignee: Camas UK Ltd
Priority date: 1985-06-27
Filing date: 1985-06-27
Publication date: 1987-04-29
Also published as: GB2181678B; GB8516216D0

Abstract

Stone blocks are treated by agitating them in a drum (8) which is rotated about its central axis. The axis is inclined to the horizontal at an angle of up to 4 DEG . The speed of rotation is between 5 and 20 r.p.m. The stone blocks may be produced by splitting reconstructed stone slabs, and the described treatment roughens the edges and corners to give the blocks a weathered appearance. <IMAGE>

Description

SPECIFICATION Stone blocks This invention relates to stone blocks and, in particular,to a method of producing stone blocks having a weathered appearance.

According to the present invention there is provided a method of treating stone blocks to achieve a weathered appearance, the method comprising agitating a pluralityofthe blocks together so that the blocks impinge one against another whereby sharp edges and corners of the blocks are broken off by impactand/orabrasion.

In this specification, the term "stone" is used to include not only natural stone, but also other stone-like materials, such as reconstructed stone, for example stone manufactured from Portland cement and natural stone aggregates, and concrete.

Pigments may also be included.Theterm "blocks" includes building blocks as well as blocks for other purposes such as paving and facing.

In a preferred embodiment of the present invention, the blocks are produced by splitting reconstructed stone slabs into the individual blocks, which are then agitatedtogetherto provide the weathered appearance.

In a preferred method in accordance with the present invention, the blocks are introduced into a vessel which is rotated to cause the blocks to tumble within the vessel so asto achieve the desired agitation. Preferably, the vessel is a cylindrical drum which is rotated about its axis. The speed of rotation of the drum is preferably such as to cause the blocks to fall from the wall of the drum beforethey reach thetop, sothatthe blocks undergo a continuous tumbling motion within the drum. The speed of rotation of the drum may, for example, be between 5 and 20 rpm. The diameter of the drum is preferably between 1 and 1.5 metres, and its length is preferably between 1.8 and 5.5 metres.

The agitating process can be made continuous by providing the drum with an inletforthe blocks at one end and an outlet at the other. The axis of the drum may be inclined slightlytothe horizontal, in order to encourage the blocks to travel from the inlettothe outlet. The angle of inclination may,forexample, be in the range of onto 40,and there may be provision for adjusting this angle.

The internal surface of the drum may be provided with a resilient lining, for example of rubber, the drum itself being made from steel.

Fora better understanding of the present invention, and to show how it may be carried into effect, reference will now be made, by way ofexam- ple, to the accompanying drawing, which is a plan view of an installation for producing blocks having a weathered appearance.

The installation comprises equipment 2 for splitting reconstructed stone slabs into blocks of a size suitable for their intended use. For example, the slabs may be 1 00mm thick and may be split into various sizes ranging from, for example, 220 x 100 x 65mm to 290 x 100x215mm,although other sizes are possible.

The split blocks are loaded onto an upwardly inclined conveyor 4 which, at its upper end, discharges the blocks into a shute 6, from which the blocks pass to a rotating drum 8. In the described embodiment, the diameter ofthe drum is 1.05 metres and its length is 5.4 metres. The drum is manufactured from steel but has an internal lining ofthick rubber. It rotates at a speed of 19 rpm. The axis of the drum is inclined to the horizontal by a small angle of less than 4% Once inside the drum 8, the blocks are repeatedly carried around the wall of the drum until they fall to the bottom of the drum.The effect isthatthe blocks are tumbled one against the other, so that sharp edges and corners are broken off as the blocks travel along the drum from the shute 6.

The length oftime during which the blocks remain in the drum depends on the degree of weathered appearance which is required, but a typical time taken for a blockto travel from one end to the other is two orthree minutes. Depending on the size ofthe blocks being treated, the throughput of the drum 8 is in the range 40-60 m2/hour, based on the superficial area of walling built, orflooring laid, using the end product.

The blocks are discharged from the drum 8 onto a shute 10 which guides them to a conveyor 12.

At the end ofthe conveyor 12 away from the shute 10, the blocks are palletized ready for distribu- tion.

During the tumbling process in the drum 8,the fragments which are broken off the blocks fall through perforations in the drum 8 onto a conveyor running below it. These fragments are discharged onto a further conveyor 14 and are removed eitherfordisposal orforanysuitable use.

The installation is controlled from a control console 16. The console 18, the stone splitting equipment 2 and the loading and unloading ends, respectively, of the conveyors 4 and 12 may be housed within a building 1 8,with the drum 8 situated outside the building 18. The conveyors 4 and 1 2 then pass through openings in the wall of the building 18. This arrangement provides protection for the operating personnel within the building 18 from the noise and dust generated during operation of the drum 8.

1. A method of treating stone blocks to achieve a weathered appearance, the method compris ing agitating a plurality of blocks together so that the blocks impinge one against the other whereby sharp edges and corners of the blocks are broken off by impact and/or abrasion.

2. A method as claimed in claim 1, in which the blocks comprise reconstructed stone blocks.

3. A method as claimed in-claim 2, in which the blocks are produced by splitting reconstructed stone slabs.

4. A method as claimed in any one of the preceding claims, in which the blocks are agitated in a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Stone blocks This invention relates to stone blocks and, in particular,to a method of producing stone blocks having a weathered appearance. According to the present invention there is provided a method of treating stone blocks to achieve a weathered appearance, the method comprising agitating a pluralityofthe blocks together so that the blocks impinge one against another whereby sharp edges and corners of the blocks are broken off by impactand/orabrasion. In this specification, the term "stone" is used to include not only natural stone, but also other stone-like materials, such as reconstructed stone, for example stone manufactured from Portland cement and natural stone aggregates, and concrete. Pigments may also be included.Theterm "blocks" includes building blocks as well as blocks for other purposes such as paving and facing. In a preferred embodiment of the present invention, the blocks are produced by splitting reconstructed stone slabs into the individual blocks, which are then agitatedtogetherto provide the weathered appearance. In a preferred method in accordance with the present invention, the blocks are introduced into a vessel which is rotated to cause the blocks to tumble within the vessel so asto achieve the desired agitation. Preferably, the vessel is a cylindrical drum which is rotated about its axis. The speed of rotation of the drum is preferably such as to cause the blocks to fall from the wall of the drum beforethey reach thetop, sothatthe blocks undergo a continuous tumbling motion within the drum. The speed of rotation of the drum may, for example, be between 5 and 20 rpm. The diameter of the drum is preferably between 1 and 1.5 metres, and its length is preferably between 1.8 and 5.5 metres. The agitating process can be made continuous by providing the drum with an inletforthe blocks at one end and an outlet at the other. The axis of the drum may be inclined slightlytothe horizontal, in order to encourage the blocks to travel from the inlettothe outlet. The angle of inclination may,forexample, be in the range of onto 40,and there may be provision for adjusting this angle. The internal surface of the drum may be provided with a resilient lining, for example of rubber, the drum itself being made from steel. Fora better understanding of the present invention, and to show how it may be carried into effect, reference will now be made, by way ofexam- ple, to the accompanying drawing, which is a plan view of an installation for producing blocks having a weathered appearance. The installation comprises equipment 2 for splitting reconstructed stone slabs into blocks of a size suitable for their intended use. For example, the slabs may be 1 00mm thick and may be split into various sizes ranging from, for example, 220 x 100 x 65mm to 290 x 100x215mm,although other sizes are possible. The split blocks are loaded onto an upwardly inclined conveyor 4 which, at its upper end, discharges the blocks into a shute 6, from which the blocks pass to a rotating drum 8. In the described embodiment, the diameter ofthe drum is 1.05 metres and its length is 5.4 metres. The drum is manufactured from steel but has an internal lining ofthick rubber. It rotates at a speed of 19 rpm. The axis of the drum is inclined to the horizontal by a small angle of less than 4% Once inside the drum 8, the blocks are repeatedly carried around the wall of the drum until they fall to the bottom of the drum.The effect isthatthe blocks are tumbled one against the other, so that sharp edges and corners are broken off as the blocks travel along the drum from the shute 6. The length oftime during which the blocks remain in the drum depends on the degree of weathered appearance which is required, but a typical time taken for a blockto travel from one end to the other is two orthree minutes. Depending on the size ofthe blocks being treated, the throughput of the drum 8 is in the range 40-60 m2/hour, based on the superficial area of walling built, orflooring laid, using the end product. The blocks are discharged from the drum 8 onto a shute 10 which guides them to a conveyor 12. At the end ofthe conveyor 12 away from the shute 10, the blocks are palletized ready for distribu- tion. During the tumbling process in the drum 8,the fragments which are broken off the blocks fall through perforations in the drum 8 onto a conveyor running below it. These fragments are discharged onto a further conveyor 14 and are removed eitherfordisposal orforanysuitable use. The installation is controlled from a control console 16. The console 18, the stone splitting equipment 2 and the loading and unloading ends, respectively, of the conveyors 4 and 12 may be housed within a building 1 8,with the drum 8 situated outside the building 18. The conveyors 4 and 1 2 then pass through openings in the wall of the building 18. This arrangement provides protection for the operating personnel within the building 18 from the noise and dust generated during operation of the drum 8. CLAIMS

4. A method as claimed in any one of the preceding claims, in which the blocks are agitated in a rotating vessel.

5. A method as claimed in claim 4, in which the vessel is rotated about an axis which is inclined to the horizontal.

6. A method as claimed in claim 5, in which the angle of inclination is not more than 4%

7. A method as claimed in any one of claims 4 to 6, in which the vessel is a cylindrical drum which is rotated about its axis.

8. A method as claimed in claim 7, in which the diameter of the drum is not less than 1 metre and not more than 1.5 metres.

9. A method as claimed in claim 7 or 8, in which the length of the drum is not less than 1.8 metres and not more than 5.5 metres.

10. A method as claimed in anyone of claims 4to 9, in which the speed of rotation ofthevessel is not less than 5 r.p.m and not more than 20 r.p.m.

11. A method as claimed in any one of claims 4to 10, in which the internal surface of the vessel has a resilient lining.

12. Amethod as claimed in any one of claims4to 11, in which the wall ofthevessel is perforated to enable small fragments of the blocks to pass out of the vessel.

13. A method as claimed in any one ofthe preceding claim, in which at least some ofthe blocks are agitated for between 2 and 3 minutes.

14. A method of treating stone blocks as claimed in claim 1 and substantially as described herein.

15. Apparatusfortreating stone blocks in accordance with any one ofthe preceding claims and substantially as described herein with reference to, and as shown in,the accompanying drawing.