Patent GB-654420-A (GB)
Title: Abrading apparatus
IPC: B24C5/06
Filed: 1948-02-29
Abstract: 654,420. Abrasive blasting. PANGBORN CORPORATION. Feb. 29, 1948, No. 6367. Convention date, June 12, 1942. [Class 60] An abrasive-particle-throwing apparatus comprises a tubular abrasive-particle feed control member, one end of said member having an edge a portion of which extends generally helically around the tubular axis of the member and has an inturned lip, and the remainder of the edge connects the helical ends to form an abrasive-particle-discharge shoot extending over a limited portion of the tube periphery, means for feeding abrasive particles within said member at a point spaced from said end, means supported for movement within the interior of said member to move the abrasive circumferentially around the interior thereof and toward said discharge shoot whereby the abrasive particles advance axially toward said end of the member and are discharged through said discharge shoot, and blades mounted for rotatable movement about said member for receiving the abrasive particles delivered from said discharge shoot and throwing the particles radially from a limited portion of the rotation circle. Abrasive from an elevated hopper is supplied to a feed spout 10, the lower end of which commuicates with a circular opening in the front end wall 11 of a hollow feed control member 12, the feed spout being attached to the wall 11 by clamps 13. A peripheral flange 14 on the feed control member 12 seats in a circular opening in the front wall of the machine housing, the member 12 being secured to the wall 15 by clamps 16. By loosening the clamps 13, 16 the member 12 can be rotatably adjusted relative to the spout 10 and wall 15. The feed control member 12 has a cylindrical wall 17 extending beyond the flange 14 and terminating in a helical edge 360 degrees in extent, provided with an inturned lip 18; a free edge 19 is thus fromed between the extremities of the helical edge, the edge extending parallel to the axis of the cylindrical wall 17. Abrasive delivered from the lower end of the spout 10 is caused to fall upon the internal surface 20 of cylindrical wall 17 adjacent the end wall 11 and away from the inturned lip 18 by a baffle wall 22 which is an end wall of a cylindrical projection 23 from the control member 12. The part 23 has openings 24 to allow abrasive from the spout 10 to fall on to the internal surface 20; the openings 24 are inclined from a radial plane, slanting outwardly in the direction of rotation. The abrasive is caused to move from the point near the end wall 11 at which it is deposited upon the surface 20 to the discharge edge 19, by impeller ribs 26 carried by a radial web 27 of an impeller 28; a cylindrical wall 29 extends from the radial web 27 approximately midway towards the free ends of the ribs 26, the internal surface of the wall 29 having approximately the same diameter as the inner edges of the ribs 26, but the external surface of the wall 29 being of smaller diameter than the outer edges of the ribs 26. The free ends of the ribs 26 extend into the annular space between the projection 23 and the internal surface 20. The side faces of the ribs 26 are parallel to each other but the outer and inner edges 30, 31. converge toward each other in a direction away from the direction of their rotation. The end face 32 of the cylindrical wall 29 is of conical formation, flaring outwardly away from the cylindrical wall 29. The impeller 28 is secured by bolt 34 to a circular boss 35 on the front face of a flange 36 carried by a shaft 37. To the flange 36 is secured a runner head 38 to the front face of which are attached a plurality of propelling blades 39, the supported edges of which are dove-tailed and received in radially extending dove-tailed grooves; endwise movement of the blades is prevented by pins 40. Specification 527,619 is referred to in connection with the mounting of the blades. In a modification, the circumferential wall of the feed control member is frustoconical with the larger end towards the runner head. The impeller ribs define a frustum of a cone, and the support for the ribs is frusto-conical. In a further modification, the impeller ribs define a cylinder, but are slightly inclined with respect to radial planes through the axis of the cylinder.