Patent GB-553099-A (GB)
Title: Improvements in processes and apparatus for spraying fusible and thermoplastic material
IPC: B05B7/20
Filed: 1941-10-31
Abstract: 553,099. Spraying fusible and thermoplastic materials. GFELLER, F., and BAIKER, L. Oct. 31, 1941, Nos. 14062, 14063 and 14064. Convention dates, Sept. 29, 1940, June 21, 1941 and July 21, 1941. [Class 69 (iii)] [Also in Group XII] Fusible and thermoplastic materials are sprayed by submitting them to the heat of explosion of combustible gaseous mixture and then projecting the fused material by the exhaust gases of the explosion. Fig. 1 shows an apparatus for spraying metal supplied in the form of wire. A handle 10 containing pipes 12 for compressed air 13 for oxygen and 14 for acetylene supports a combustion chamber 21 provided with a sparking plug 38 and having in front a funnel shaped nozzle 23 and at the rear a conical nozzle 24 through which passes a guide tube 29 for the fusible wire. The explosive mixture is introduced into the chamber 21 through a nozzle 34 having an inner tube 35 connected to compressed air pipe 12 through a regulating valve 37 the combustible gas pipe 13 being connected to an annular passage formed in the nozzle. Melting of the wire is assisted by an annular flame formed at the outlet of the nozzle 24 fed with a combustion mixture from a mixing nozzle 32 mounted in a collar 30 on the guide tube 29 and supplied with combustion gas and oxygen from the pipes 13, 14. The wire is fed to the spraying nozzle by mechanism driven by a turbine 45 supplied with compressed air from the pipe 12. Electric leads 40, 41 are connected to the sparking plug and casing respectively. Figs. 3 and 5 show an apparatus in which a reservoir 62 for thermoplastic material e.g. bitumen is mounted on a disc 56 carried by a handle 10 and contains an explosion chamber 21 to which is attached a metal blade 65 for communicating heat to the material. The combustion chamber has a sparking plug 38 mounted therein and is supplied with an explosive mixture through a passage 101 to which air is supplied by a central tube 102 and combustible gas through a pipe 98. The explosion products are ejected through a pipe 59. To prevent overheating the chamber 21 may have an air jacket fed from the pipe 96 through a tube 107 regulated by a valve 106. The air from the jacket mixes with the explosion products in a tube 60. The molten material is led to a nozzle 58 within which slides a tube 61 serving as a valve and operated against the action of a spring 75 by a trigger 82. The gas supply is regulated by a valve 89, Fig. 5, operated by a trigger 85 the arrangement being such that first the fuel valve and then the valve 61 is opened. After the first few explosions the pistol becomes sufficiently heated that self ignition of the mixture takes place when the sparking plug can be dispensed with. The Specification as open to inspection under Sect. 91 also describes an apparatus comprising a pear shaped explosion chamber 7, Fig. 1 (Cancelled) provided with a sparking plug 6 and fed with an explosive mixture the products of which are led through a passage 7 to a spray nozzle fed with wire through a tube 15. Acetylene is fed through a pipe 3 and oxygen through a pipe 4 past non-return valves 23, 24, Fig. 3 (Cancelled) through passages in discs 19, 20 by which they are mixed and distributed to the chamber 7. The tube 15 is provided with ribs 15r to assist in conducting heat to the wire. The wire is fed to the tube 15 by mechanism operated by the explosions comprising a cylinder 25, containing a spring pressed piston 26 and connected to the chamber 7 by a tube 29. The piston rod 28 is provided with an eye 281 engaging a pin operating ratchet gearing which rotates a disc 39 between which and the disc 40 the wire is led into the tube 15. The combusion chamber 7 is provided with cooling ribs and the nozzle with a silencer 16. This subject-matter does not appear in the Specification as accepted.