GB1301860A - - Google Patents

Abstract

1301860 Extruding clay COAL INDUSTRY (PATENTS) Ltd 17 Nov 1970 [23 Dec 1969] 62653/69 Heading B5A [Also in Division E1] Non load-bearing, decorative brick facing slips, comprise a surface formed with a plurality of channels for keying to a base with mortar. The channels are formed by slicing longitudinally through a row of holes in a rectangular or circular section clay column issuing from an extrusion nozzle, by means of a wire extending thereacross, to define opposed channelled surfaces of superimposed clay layers, each of the thickness of the slip and which are then cut transversely into the required slip lengths for firing. With a single row of holes, and unchannelled surfaces of the slip are smooth, due to the extrusion nozzle effect, but the sliced surfaces are roughened by the wire, which also forms inturned lips 9, Fig. 3, to each channel 8. The column holes may be circular, rectangular, or configured to produce dovetailed recesses as in the Fig. 4 embodiment, wherein the opposed channelled surfaces of layers 14, 15 are formed by the wire 17, with further wires 16, 18, forming roughened unchannelled surfaces of these layers, and of layers 12, 13, the channelled surfaces whereof are formed by the extrusion die 1. In the Fig. 5 embodiment, four or more layers are sliced by wires 16, 17 and 18, which form roughened surfaces, with the unchannelled surfaces of the exterior layers 12, 13 being roughened by slicing by wires 19, 20.