| 摘要 |
766,088. Spray-producers. DE VILBISS CO. March 16, 1955 [March 29, 1954], No. 7726/55. Class 69 (3). In a spray gun in which material is atomized by an air stream, a small regulated proportion of an additive agent such as a catalyst, curing agent, coagulant, &c., is introduced into the air stream before the atomization, whereby the agent is thoroughly mixed with the material during its atomization. In Fig. 1 the gun has air and material inlets 4 and 8, and air and material control valves 10 and 35 respectively operated in known manner by a trigger 3. A further valve 29 controls the air flow to discharge passages 33 whereby the atomized stream is flattened; the remainder of the air discharges about the material tip 25. When the trigger is operated a small quantity of air descends from an annular space 15, down bore 47 and through passages 51, 52 and into a cylinder 53, Fig. 2, and acts upon a piston 54 to open a valve 44. The agent, fed at 7, is thereby allowed to pass through a tube 50 and from a nozzle 49 into the main air stream. The position of a groove 60 in the shoulder of the valve 44 relative the part 61 controls the quantity of agent flowing, and is predetermined by an adjustable stop 58. In a further embodiment the agent inlet is adjacent the material inlet at the front of the gun and the supply of agent is controlled by a needle valve directly operated by the gun trigger. A part of the air supply is led to air flattening jets and the remainder, which leads to the space surrounding the material outlet, is fed with the agent. In order to discontinue spraying when decrease in agent discharge occurs, a conventional flow meter 101 is arranged in the agent supply line 102, and depending from a float 103 is a secondary float and armature 106. The armature co-operates with an electric coil 107 when the flow rate drops, and the electric current fluctuation thereby produced in the coil is amplified and used to close a valve 111 controlling the delivery of spraying material through a line 112 to the gun. A warning light 109 is provided. |
