GB1480959A - Blasting apparatus - Google Patents

Abstract

1480959 Blasting IAN HEATH Ltd 10 Nov 1975 [24 Aug 1974] 37371/74 Heading 3BD Apparatus for subjecting a workpiece to a blast of fluid comprises a chamber 10, a nozzle 11 in the chamber and means for feeding fluid to the nozzle, the chamber having an opening 13 and a structure 14 which is adapted to close the opening and support a workpiece. The structure is movable relative to the chamber between a loading position, in which the workpiece supporting means is accessible from outside the chamber for loading a workpiece on the supporting means, and an operative position, in which the opening is closed by the structure and a workpiece is positioned to receive the blast from the nozzle. The chamber 10 is cuboid in shape and a door 12 is formed with the opening 13 which is circular and has an annular seal of rubber. The nozzle 11 is directed towards the opening and is fed with a stream of water containing particles and a stream of air under pressure. The structure 14 is mounted on a framework 15 movable about a vertical pivot 16 on bars 16 when a strut 19 between the framework and chamber 10 is released from the chamber to provide access to the door. A motor 20 on the framework is connected by a chain drive 22 to a gear 21 freely rotatable on a shaft 25 but prevented from axial movement relative to the framework. The shaft 25 is hollow and at one end carries a head 26 formed with a socket 27 for receiving a cup-shaped workpiece. The shaft is axially slidable in bearings in the framework by means of a toggle mechanism 30, 31 having a handle 32 from the position shown in Fig. 1, in which the head 26 is spaced from the chamber 10 to permit loading of the workpiece into the socket 27, to the position shown in Fig. 2 in which the head engages the annular seal and a clutch member 29 fixed to the shaft engages a clutch member on the gear 21 whereby the shaft and head are rotated. When the head is moved to the operative position, a control actuates the feed of water and solid particles to the nozzle and the air supply is controlled by timing device so that the workpiece is blasted during one rotation thereof. On return of the head to the loading position, an ejector rod 33 partly ejects the workpiece from the head so that it can be removed by hand. The supporting means may grip the workpiece internally to leave the external surface exposed for blasting, the workpiece passing completely through the opening into the chamber.