GB2136348A - Clay paviors - Google Patents

Abstract

A rectangular clay pavior with vertically extending nibs (5, 6, 7, 8) on its side and end faces (2, 3) disposed such that adjacent paviors are evenly spaced by the nibs and that nibs of adjacent paviors do not come into contact is made by extruding a strip of clay and cutting the strip transversely to produce individual paviors. The edges of the top and bottom faces (1, 4) of the pavior are chamfered, the upper and lower end portions of the nibs (5, 6, 7, 8) being cut away. <IMAGE>

Description

SPECIFICATION Clay paviors It is known in tiles and other constructional elements to provide spacers or nibs extending from the edges of each element in order that when identical elements are arranged in regular array, equal spaces are left between them resulting in a pleasing regular appearance. Such nibs do not extend over the entire depth of the element but are located away from the upper face in order that when cementing and/or grouting is carried out, the nibs are covered by the cement or grouting material and are not visible in the finished array.

Such elements are conventionally made by pressing from a sheet of the appropriate material.

It is under some circumstances advantageous to manufacture clay paviors by extrusion of a strip of clay having a cross-section of shape corresponding to that of the finished pavior.

Although such paviors, indeed even pressed paviors, have hitherto had flat side faces, and have been spaced apart by a small distance during laying, it has been found that the vibration applied to settle and bed the paviors in place has led to damaging abrasion of the sides and corners of the individual paviors where they come into contact.

We have found that the provision of nibs on the side faces would overcome this, concentrating any abrasion on the nibs themselves, but such nibs, formed easily in a pressed body cannot easily be formed in an extruded body. The aim of the invention is to allow the provision of nibs on an extruded pavior without detracting from the appearance of the finished pavement.

According to the invention we provide a method of manufacture of clay paviors incorporating nibs on the side end faces of the paviors comprising an extrusion step in which is formed a strip of clay having cross section corresponding to that of the pavior complete with nibs extending the full depth of the side and end faces, a cutting step in which individual paviors are cut from the extruded strip by cutting substantially transversely of the strip, and a chamfering step in which the edges of at least the upper face of each pavior are chamfered. In this way, the upper end portions of the nibs of the finished pavior are disposed below the level of the upper face of the pavior so that bedding resuits in the upper end portions of the nibs being covered over in the finished pavement.In a preferred embodiment, the edges of the lower face of the pavior are chamfered in addition to those of the upper face.

According to a further feature of the invention we provide a clay pavior manufactured according to the above method. In a preferred embodiment the nibs are so arranged that when the finished pavior is placed in the required regular array, the nibs of adjacent paviors do not coincide. This may be achieved in a rectangular pavior by providing one end nib on each of the end faces and two side nibs on one of the side faces, the two end nibs being located at different positions on their respective end faces, and the two side nibs being located at differing distances from the ends of the pavior.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 7 is a perspective view of a clay pavior according to one aspect of the invention; Figure 2 is a plan view of the pavior shown in Figure 1; and Figure 3 is an enlarged cross-section on line II I-Ill of Figure 2.

Figures 1 and 2 show a clay pavior made by extrusion using a die of cross-section corresponding to the outline of Figure 2 and having an upper face 1, end faces 2, side faces 3 and a lower face 4. Nibs 5, 6, 7, 8 are provided on the end faces 2 and side faces 3 respectively, one end nib 5, 6 on each end face 2 and the side nibs 7, 8 on one of the side faces 3. The nibs are arranged so that when a number of identical paviors are placed in an array, the nibs serve to space adjacent paviors apart but cannot coincide; the latter property is achieved as shown in Figure 2 by locating the end nibs 5 at unequal distances from respective sides of the pavior, the side nibs 6, 7 being located at unequal distances from respective ends of the pavior.

The edges around the upper and lower faces 1, 4 of the pavior are chamfered, and in chamfering these edges the upper end portions of the nibs are also cut away and chamfered as shown in Figure 3. In this way, when the paviors are placed in an array, with the nibs of one pavior in contact with the sides of adjacent paviors, the gaps between the paviors can be filled with sand and/or grouting compound which, even when only brought up flush with the lower edges of the upper chamfers, conceals the nibs. The chamfered edge on the lower edge of the pavior promotes the flow of bedding material (e.g. sand) into the joints when vibration is applied during bedding, and the provision of two chamfered edges rather than only one means that the pavior is reversible in case of damage to one of the upper or lower faces.

1. A method of manufacture of clay paviors incorporating nibs on the side and end faces of the paviors comprising an extrusion step in which is formed a strip of clay having cross section corresponding to that of the pavior in plan view complete with nibs extending the full depth of the side and end faces, a cutting step in which individual paviors are cut from the extruded strip by cutting substantially transversely of the strip, and a chamfering step in which the edges of at least the upper face of each pavior are chamfered.

2. A method according to Claim 1 in which the edges of the lower face of each pavior are chamfered in addition to those of the upper face.

3. A clay pavior manufactured by the method according to Claim 1 or Claim 2.

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

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Clay paviors It is known in tiles and other constructional elements to provide spacers or nibs extending from the edges of each element in order that when identical elements are arranged in regular array, equal spaces are left between them resulting in a pleasing regular appearance. Such nibs do not extend over the entire depth of the element but are located away from the upper face in order that when cementing and/or grouting is carried out, the nibs are covered by the cement or grouting material and are not visible in the finished array. Such elements are conventionally made by pressing from a sheet of the appropriate material. It is under some circumstances advantageous to manufacture clay paviors by extrusion of a strip of clay having a cross-section of shape corresponding to that of the finished pavior. Although such paviors, indeed even pressed paviors, have hitherto had flat side faces, and have been spaced apart by a small distance during laying, it has been found that the vibration applied to settle and bed the paviors in place has led to damaging abrasion of the sides and corners of the individual paviors where they come into contact. We have found that the provision of nibs on the side faces would overcome this, concentrating any abrasion on the nibs themselves, but such nibs, formed easily in a pressed body cannot easily be formed in an extruded body. The aim of the invention is to allow the provision of nibs on an extruded pavior without detracting from the appearance of the finished pavement. According to the invention we provide a method of manufacture of clay paviors incorporating nibs on the side end faces of the paviors comprising an extrusion step in which is formed a strip of clay having cross section corresponding to that of the pavior complete with nibs extending the full depth of the side and end faces, a cutting step in which individual paviors are cut from the extruded strip by cutting substantially transversely of the strip, and a chamfering step in which the edges of at least the upper face of each pavior are chamfered. In this way, the upper end portions of the nibs of the finished pavior are disposed below the level of the upper face of the pavior so that bedding resuits in the upper end portions of the nibs being covered over in the finished pavement.In a preferred embodiment, the edges of the lower face of the pavior are chamfered in addition to those of the upper face. According to a further feature of the invention we provide a clay pavior manufactured according to the above method. In a preferred embodiment the nibs are so arranged that when the finished pavior is placed in the required regular array, the nibs of adjacent paviors do not coincide. This may be achieved in a rectangular pavior by providing one end nib on each of the end faces and two side nibs on one of the side faces, the two end nibs being located at different positions on their respective end faces, and the two side nibs being located at differing distances from the ends of the pavior. An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 7 is a perspective view of a clay pavior according to one aspect of the invention; Figure 2 is a plan view of the pavior shown in Figure 1; and Figure 3 is an enlarged cross-section on line II I-Ill of Figure 2. Figures 1 and 2 show a clay pavior made by extrusion using a die of cross-section corresponding to the outline of Figure 2 and having an upper face 1, end faces 2, side faces 3 and a lower face 4. Nibs 5, 6, 7, 8 are provided on the end faces 2 and side faces 3 respectively, one end nib 5, 6 on each end face 2 and the side nibs 7, 8 on one of the side faces 3. The nibs are arranged so that when a number of identical paviors are placed in an array, the nibs serve to space adjacent paviors apart but cannot coincide; the latter property is achieved as shown in Figure 2 by locating the end nibs 5 at unequal distances from respective sides of the pavior, the side nibs 6, 7 being located at unequal distances from respective ends of the pavior. The edges around the upper and lower faces 1, 4 of the pavior are chamfered, and in chamfering these edges the upper end portions of the nibs are also cut away and chamfered as shown in Figure 3. In this way, when the paviors are placed in an array, with the nibs of one pavior in contact with the sides of adjacent paviors, the gaps between the paviors can be filled with sand and/or grouting compound which, even when only brought up flush with the lower edges of the upper chamfers, conceals the nibs. The chamfered edge on the lower edge of the pavior promotes the flow of bedding material (e.g. sand) into the joints when vibration is applied during bedding, and the provision of two chamfered edges rather than only one means that the pavior is reversible in case of damage to one of the upper or lower faces. CLAIMS

1. A method of manufacture of clay paviors incorporating nibs on the side and end faces of the paviors comprising an extrusion step in which is formed a strip of clay having cross section corresponding to that of the pavior in plan view complete with nibs extending the full depth of the side and end faces, a cutting step in which individual paviors are cut from the extruded strip by cutting substantially transversely of the strip, and a chamfering step in which the edges of at least the upper face of each pavior are chamfered.

2. A method according to Claim 1 in which the edges of the lower face of each pavior are chamfered in addition to those of the upper face.

3. A clay pavior manufactured by the method according to Claim 1 or Claim 2.

4. A clay pavior according to claim 3 of substantially rectangular cross-section in which one end is provided on each of the end faces and two side nibs on one of the side faces.

5. A clay pavior according to Claim 4 in which the two end nibs are located at different positions on their respective end faces, and the two side nibs are located at differing distances from the ends of the pavior.

6. A method of manufacture of clay paviors substantially as described with reference to the accompanying drawings.

7. A clay pavior substantially as described with reference to the accompanying drawings.