Patent ID: 6062957
Filing Date: 2000-05-16
Classification: B24C

Abstract:
A dry abrasive blasting head having rotating nozzles, comprising:(a) a tube having a front end and a rear end and having a longitudinal axis about which said tube rotates;(b) a housing, not rotating and surrounding a portion of said tube adjacent the rear end of said tube, said housing having a front end and a rear end;(c) a front end plate attached to and closing the front end of said housing and including a hole through which said tube extends;(d) a rear end plate attached to and closing the rear end of said housing, said rear end plate including a coupling for connecting to said rear end plate a conduit through which a high velocity stream of dry abrasive particles suspended in air is discharged into said tube in a forward direction;(e) a front seal in sealing engagement with said front end plate and said tube;(f) a rear seal in sealing engagement with said rear end plate and said tube;(g) a bearing located axially between said front seal and said rear seal and supporting said tube within said housing for rotation about the longitudinal axis of said tube with a front portion of said tube extending forward of said front end plate;(h) a nozzle holder mounted to the front end of said tube and including a central chamber and a plurality of hollow branches extending obliquely outward and forward and communicating with the central chamber, the hollow branches equally spaced circumferentially, and the central chamber extending forward beyond its juncture with the hollow branches;(i) a plurality of nozzles each attached to one of said plurality of hollow branches for discharging from the blasting head the high velocity stream of air-suspended abrasive particles;(j) at least one vent hole formed in the blast head behind the rear seal for venting abrasive particles; and(k) the nozzle holder further including a cup-like reservoir at the front end thereof for at least partially filling with particles during operation of the blasting head to protect the nozzle holder front end from abrasion by the high velocity stream of air-suspended particles.