Patent GB-640592-A (GB)
Title: Blasting rooms
IPC: B24C9/00
Filed: 1948-02-16
Abstract: 640,592. Sand-blast. KEEFER, W. L. Feb. 16, 1948, No. 4443. Convention date, March 2, 1946. [Class 60] A blasting room comprises a vertically movable wall section, a blast gun on the room side of said wall section and mounted thereon for at least limited universal movement relative thereto and vertical movement therewith, flexible conduit means at the room side of said wall section and connected to said blast gun for conducting blasting particles and high pressure fluid thereto, the mounting of the blast gun on said movable wall section transferring the reaction of the high pressure blast to said movable wall section, and means for controlling the discharge of said blast gun from outside said movable wall. The invention is stated to be particularly applicable to core knockout rooms in which a jet of water and absorbent is employed to breakdown and blast away the moulding cores used in the founding of large hollow castings. The blast-room comprises an enclosure 10 having entrance doors 10a, a pit 10b, and suitable accessories for transporting the casting into and from the room, and for supporting them in position to be worked upon therein. A section of the wall of the enclosure 10 is replaced by a vertically slidable wall section 11, carrying a blast gun 12, and forming the inner face of an operator's vestibule having side walls 13. The blast-gun 12 has a sand-hose 14 and a fluid conduit comprising a double elbow 15 having its lower vertical end flanged and turnable in a packing ring 16 and having its upper opposed horizontal ends delivering to a coupling 17 swingable in the vertical direction. The ring 16 is mounted by bracket 18 on the slidable wall 11, and the lower end of double elbow 15 is supplied with pressure fluid, e.g. water, through the ring 16 and hose connection 19. The gun is manipulated, by the operator, by means of a control rod 21 extending through a flexible boot 22. An inclined window 23 is provided, and is kept clean by water discharged from slots or projections in a pipe 25; a removable safety screen may be provided. On the exterior of the vertically slidable wall section 11 an operator's platform 26 is provided, having a push button or like control 27 for effecting raising or lowering of the entire wall-gun-platform assembly. The operator's station is also provided with footcontrolled switches and hand-operated switches for controlling (i) the movement of the turntable, work conveyer or other support on which the castings are mounted, (ii) the supply of sand to the gun and (iii) the pressure of water supplied to the gun. The sliding wall is a rigidified section in the run of a flexible band 30, e.g. a multiply rubber belt or curtain, which passes over guide rolls 31, 32 at the tops of the vestibule and at the bottom of the pit, its ends being connected to reel-rolls 33, 34. The wall-forming section 11 of the belt 30 runs at its edges in guideways provided between angle irons 35, carried by vestibule walls 13, and extending from top to bottom. The section 11 is rigidified by angle-iron frame 40 suitably secured, as by rivets, to the belt and carrying platform 26. The driving of the reels 33, 34 under control of the push button switch 27 is effected by a motor 41; limit switches 30a, 30b operated by the platform 26 are provided to prevent over-travel of the belt 30. The reel rolls 33, 34 have driving sprockets 47, 48, connected by a chain 45, 46, one run of which contains a heavy tension spring 49 to allow for the change in effective diameter of the rolls 33, 34 as the belt is wound on or off.