Manufacture of Cement-Based Paving Articles

Abstract

A method for the production of a clay or cementitious construction unit, such as a paving block or slab, having a textured face surface, comprising contacting the intended face surface of an incompletely hardened, free-standing, self-supporting clay or cementitious construction unit (2), (3), with a water-absorbent porous membrane (6), for example of paper or other non-woven fibrous material, contacting the membrane-covered surface of the unit with the contact surface of a vibratable element (9), the contact surface of the vibratable element having a non-relief surface, or carrying a reverse image of a desired relief pattern to be applied to the face surface of the unit, vibrating the vibratable element with vibration head(s) (10), (11), (12) at a frequency greater than 14 KHz while it is in contact with the membrane-covered face surface of the unit, breaking contact between the textured face surface of the incompletely hardened unit and the membrane, and hardening the construction unit. Apparatus is also described, it which a lifting and lowering piston (4) lifts a tray (1) carrying the construction unit blanks into and out of contact with the membrane (61), the vibratable element (9) and the vibration head(s) (10), (11).

Dependencies are inferred from the claim text.