GB1450833A - Spray gun - Google Patents

Abstract

1450833 Spray producers COMMONWEALTH INDUSTRIAL GASES Ltd 19 March 1974 [21 March 1973] 12053/74 Heading B2F A spray gun comprises a barrel portion 26, Figure 2 having a spray nozzle assembly 27 at one end and a hand-piece 28 at the other end. an air supply union 49 on the hand-piece opening into an air supply duct 48 having an on-off valve 50, 51 therein, with the portions of the duct 48 on each side of the on-off valve being axially coincident, a liquid supply union 67 feeding the nozzle assembly via a manually operable liquid-flow control valve 40, 47, wherein the movable valve elements 58, Figure 4, 62 of the on-off valve and 47, 63 of the liquid-flow control valve are coaxially mounted one upon the other, and are movable relative to each other to a limited extent, such that when the on-off valve is operated by a trigger 68, a subsequent opening of the liquid-flow control valve is effected. When the trigger is released the valves are closed in reverse order. Air supply duct 48 communicates with the nozzle assembly 27 via an air flow control duct 29, flow being controlled by an adjustable control valve element 31 abutting a seating 30 in the barrel portion 26. The on-off valve comprises a valve sleeve 51 in a generally cylindrical cavity 50 formed in the hand-piece 28, the cavity 50 intersecting the air-supply duct 48. Valve sleeve 51 is sealed relative to the walls of the cavity 50 by a resilient sealing ring 59 held in a serpentine groove (60) Figure 5 (not shown) in the sleeve 51. In operation, depression of the trigger 68 causes tubular stem 63 to move valve element 58 away from a seat 57 in sleeve 51, permitting air to flow to the duct 29 through openings 54, 55, 56 in the sleeve 51. Thereafter the end of stem 63 bears against a head 64 secured to valve element 47, so opening the liquid flow-control valve. Relaxation of trigger pressure causes springs 65 and 61 to revert valve elements 47 and 58 to their closed positions, in that order. Nozzle assembly 27 comprises an inner body 40 having an outlet opening 46 controllable by the valve element 47, a tip element 41 being secured to the body 40 and barrel portion 26 by a ring nut 42. The nozzle assembly defines an annular chamber 43 fed with air from the duct 29 and having a plurality of air outlet orifices 44, 45. A hook 39 is provided for suspending the spray gun when not in use.