GB1166515A - Production of Hardened Brick Products - Google Patents

Abstract

1,166,515. Moulding bricks. J. P. AIKEN. 24 Nov., 1967, No. 53682/67. Heading B5A. Apparatus for the continuous production of hardened bricks includes an extruder 17, Fig. 2, which continuously extrudes a brick mix, a cutter 20, Fig. 3, for cutting the extrudate 46 into blocks which are preheated by an infra-red heater, and a dielectric heater for the further heating of the blocks. The latter heater comprises a lower electroconductive belt or electrode on which the blocks are conveyed and an upper electrode spaced therefrom. The brick mix includes at least 1% by weight of wollastonite to form a uniform mixture of low water content, and is fed at 28 to the extruder and forced by a worm 34 through holes 35 as separate streams which fall through chamber 37 to an extrusion chamber 29 which gradually tapers to a suitably shaped extrusion orifice 32 through which the mix is forced by a worm 31. Vacuum lines 33 are connected to the chamber 37, and compressed air is fed about the extrudate via outlets 42. The cutter comprises a number of parallel, spaced, transversely vibrating saw members 47 depending from a frame 48 which is driven horizontally at the same speed as the extrudate on a slide member 50 lowered by a cam mechanism against springs 59a. From the upper, or initial position of the cutter it is moved downwardly slightly by hydraulic cylinders 63 whereupon a cam roller 62 on a linkage 53, 54 is lowered to engage below a sloping cam track 59; when horizontal movement is imparted to the cutter by a drive mechanism 55 and the linkage 53, 54 further vertical movement is imparted to the cutter which sub-divides the extrudate into blocks. At the end of the horizontal stroke the cam roller engages a horizontal track and is quickly returned to the initial position. Each saw member 47 is carried in a guideway 68 and vibrated longitudinally by a cam member on a shaft 71 and rotatably mounted in a hole in the member.