GB1051620A - - Google Patents

Abstract

1,051,620. Blasting. GEORG FISCHER A.G. March 25, 1965 [April 8, 1964], No 12796/65. Heading B3D. An abrasive blasting machine has a treatment chamber provided with a plurality of throwing wheel units, and with closable apertures on opposite sides thereof, a conveying track extending through the apertures and across the chamber, at least one carriage movable to and fro on the track and provided with a releasable and securable turntable for supporting articles to be treated and lift-up doors incorporating dependent curtains for closing the apertures, the curtains being arranged so that the or each carriage, bearing articles for treatment up to a predetermined height, can move into and out of the chamber through the curtained parts of the doors without lifting the doors from the closed position. Throwing wheel units 11, 12 driven by electric motors 16, 15 are arranged above a treatment chamber 1 through which extends a track 3 having rails 2, 2. A carriage 6 is movable on the rails by an electric motor 20, steplessly variable transmission 21 and chain system 5. The carriage carries a turntable 17 rotatable in either direction by an electric motor 19. Apertures at opposite ends of the treatment chamber have doors 9 vertically movable by an electric motor 7 and rope systems 8. The doors have curtains 10 formed of rubber strips. For treating girders &c. the workpiece is placed on the turntable 17 of the carriage 6 and run into the treatment chamber 1 at high speed; the doors 9 remain closed, the curtains 10 permitting entry of the workpiece. When the workpiece reaches the treatment zone the travel is changed to slow speed. In the case of transversely ribbed girders, the workpiece is, after a run in one direction, turned through 180 degrees outside the treatment chamber 1 by the turntable 17 and run back through the treatment chamber in the opposite direction. For treating tall workpieces, the doors 9 are raised to permit entry and discharge of the workpiece. The carriage 6 can be reciprocated through a short distance and the turntable 17 rotated. Two carriages 6 may be provided, one being loaded or unloaded while the other is in the treatment chamber.