GB332849A - A portable apparatus for sandblasting, scouring or abrading surfaces of ships, bridges, buildings or the like - Google Patents

Abstract

332,849. Bailey, B. M. Nov. 5, 1929. Washing or cleaning by use of sand and abrading- agents. - A portable apparatus for scouring &c. the surfaces of buildings &c. by means of a blast of air, steam or other fluid and sand, grit, metallic grit, &c. consists of a casing a having a handle b and formed with a pipe c connected to a source of negative pressure and leading to a groove d at the front of the casing. This negative pressure is utilized to form a seal between a grooved rubber ring g, carried by a mouthpiece e, with passages, j, k therein, and the surface being scoured, the part e being secured to the casing by a clamping ring f. An opening at the rear of the casing is closed by a block m pivoted to the casing at n, bearing against a resilient gasket o, and carrying a plate p on which are mounted two nozzles q and, by means of wings s, two jet tubes t in alignment with the nozzles. The block m has a tubular arm portion u with an inlet v for pressure fluid, and also has a valve chamber wand a tubular extension x with a seating y, which may be closed by a spring pressed valve z operated by a plunger 11 in the handle b provided with a thumb button 12. In the chamber w is a spring-pressed valve 14 which moves, when the valve z is closed and the ring g is pressed up to the surface being worked, under the influence of the negative pressure to admit pressure fluid to the nozzles. A baffle plate 18 with openings therein is spaced from the top of the casing, and above the baffle are openings 19 leading, through passages 20, to a filter bag 22. The abrasive 24 is placed in the body of the casing, and in operation, the blast operates on the surface within the ring g, the block m being rocked by pressure on the button 12 to move the tubes and thus sweep the blast upwards. Spent abrasive falls back into the casing, lighter particles passing out to the bag 22. If the seal formed by the ring g is broken or the button 12 be released, the valve 14 closes and shuts off the blast. The mouthpiece e may be shaped according to the work to be performed, for example, for working in corners or on stepped plates; rollers may be fitted to the mouthpiece where great adhesion is not required. An observation window 25 is provided. According to the Provisional Specification, the pressure fluid is conveyed through a valve to a chamber containing jets arranged to create a partial vacuum in the chamber, and the outlet of the chamber is connected to a series of jets pivotally mounted in a second chamber containing the abrasive and having an orifice pressed against the surface under treatment, and sealed by a perforated cushion connected to the first chamber or to an exhausting pump.