Patent GB-478882-A (GB)
Title: Improvements in or relating to spraying apparatus for cement, paints and other liquids and substances
IPC: E04F21/12
Filed: 1936-07-22
Abstract: A method of spraying cement and/or other substances consists in producing a cloud of cement or like particles in a container, causing the cloud to issue from a nozzle by means of an ejector device associated with the nozzle, and causing said cloud, after it has left the nozzle, to intermingle with a cloud composed of particles of water or other liquid directed away from the nozzle. The spraying device shown in Figs. 4 and 5 is in the form of a gun having a hollow hand-grip 17 through which cement or other finely - divided solids pass.  The bore 18 of the grip terminates in a flared part 19 fitted with a choke tube 20.  This flared part is provided with two concentric grooves 21, 22, which are supplied with liquid and air respectively by supply pipes.  The supplies of air and liquid are regulated by screw-down valves 33, 39, and spring-controlled valves 35, 41.  The liquid passes through a number of nozzles 25 which are mounted in apertures in a coned washer 23 and which pass through a number of holes 27 in a second coned washer 26.  The air passes from the groove 22 through apertures 24 and annular groove 30 in the washer 23 and issues from the holes 27 to atomize the liquid issuing from the nozzles 25.  The washers are held in place by a screwed member 31.  The ejector nozzle 55 for the dry cement or other substance is supplied with air by conduits leading from the passage 34 which is disposed between the valves 34, 35.  A trigger device 50 is fitted with cams 53 which engage with collars 46 <PICT:0478882/III/1> <PICT:0478882/III/2> <PICT:0478882/III/3> associated with the spring-controlled valves.  The arrangement is such that, as the trigger is pulled, air is first supplied through the apertures 28, then liquid is supplied to the nozzles 25, and finally sufficient air is supplied to the nozzle 55 to commence the solids ejector action.  The solids are fed to the bore in the grip 17 through a pipe 15, Fig. 7, which leads to a fan-shaped nozzle 98 disposed in rotatable mixing barrel 83.  The material is fed to the barrel through a charging funnel 97.  The barrel consists of a conical casing 89 comprising two hinged sections, and two end discs 84, 85, which are secured to bosses 86 mounted upon ball bearings on a fixed shaft 79.  Blades 92 agitate the material to produce the necessary cloud of particles, when the drum is rotated by a motor 93. A colour pot 63 is detachably fitted to the top of the gun and the interior thereof is in communication with the bore 18.  The pot comprises a lid 75 rotatably mounted on a horizontal portion of the pipe 77, and a container 66 which is screwed to the lid and which is provided internally with a number of blades.  Rotation of the container by hand produces a cloud of the particles of cement, coloured solid matter or pigment contained therein.  The container can readily be replaced by another container containing a different pigment.  The rotary pot and the rotary barrel 83 may be used alone or both may be employed in the spraying operation.  In a modified arrangement, coloured liquid is supplied under pressure to the nozzles 25.  A number of vessels, containing different primary colours may be provided and a system of valves is provided to regulate the supply of the coloured liquids to the nozzles in any desired combination.