| 摘要 |
<p>The problems deriving from even slight dishomogenities of the density of filling of molds for forming abrasive wheels with a powdery abrasive.mixture induced by the levelling action by repeated passes of a scraper blade moving along the same line onto the surface of a mold table (2) are overcome by performing the. following succession of operations: - lifting a mobile bottom (4) of a mold table hole (3) at a first level equal to or lower than the level of the surface of the mold table; - depositing on the surface of the mold. table (2) a layer of a certain uniform of thickness of abrasive mixture while maintaining the mobile bottom (4) at said first lifted level; - lowering inside the hole (3) through the mold table (2) said mobile bottom (4) sustaining the mass of abrasive mixture bearing on its surface; - lifting said mobile bottom (4) to a second preestablished level equal to or lower than said first level; - removing the abrasive mixture of said deposited layer, from the surface of the mold table (2) levelling the abrasive mixture filling of said mold cavity; - lowering said mobile bottom (4) inside said hole (3). The method is effective even in case of forming by pressing at room.temperature ultrathin grinding wheels and/or incorporating one or more reinforcement nets, to be successively hardened in oven.</p> |
