US1748440A - Spraying apparatus - Google Patents

Description

Feb. 25, 1930. c. L. BURDICK ,743,440

SPRAYING APPARATUS Filed uarcn SQ 1926 Patented' Feb. 25, 1930 CHARLES LAURENCE BUBDICK, OF LONDON, ENGLAND SPRA'YING APPARATUS Application kledy Iarch 5, 1926, Serial No. 82,623, and in Great Britain Iaroh $0, 1925.

My invention relates to machines for distributingliquids by compressed air for certain decorative ei'ects.

Ordinary sprays which are used for distribo uting paints, colours, varnishes and the like are designed to produce a very complete atomization completely covering the surface; the main object of my invention is to distribute liquids with little or no atomization and to produce lines or splashes, or both with regularity but without set design.

` The viscosity of the liquid will to some ex- .tent determine the character of the results produced, but to ensure regularity (which is a very important factor for decorative effects) with any particular liquid, I have designed an especial spraying nozzle to be used preferably in connection with a forced feed for the liquid, regulated by an automatic reducing or control valve, or by a, gravity feed.

The invention accordingly has/for an object to provide and comprises the improved apparatus of which the features are hereinafter described and specifically claimed in addition to the improved process of obtaining the peculiar decorative effects by spraying and the product so obtained.

The main feature of the apparatus lies in the formation of the nozzle in such a way that compressed air impinges from several directions uponthe somewhat viscous liquid (which is pressure fed) as it emerges from a liquid orifice, to draw it out into l1nes and splashes, as opposed to the ordinary arrangements in which painting is accomplished evenly over a surface by dividing or atomizing the liquid as completely as possible.

Referring to the accompanying drawings l Fig. 1 is an elevation of a preferred form of apparatus made in accordance with the in vention.

Fig. 2 represents the appearance Aof a surface treated thereby, showing how the liquid Y falls upon the surface in strings and splashes.

Fig. 3 is a sectional elevation on an enlarged scale of the nozzle arrangement. E

Fig. 4 is a partial front elevation of thesame, and

Figs. 5 and 6 are corresponding views of a modified form of nozzle.

The apparatus as shown comprises a handle 1 and a trigger 2 for controlling the supply of liquid and compressed air. The liquid is contained in a reservoir 3 supported upon a connecting pipe 4 through which it is fed to the liquid nozzle 5. Compressed air is supplied to the connection 6 and throigh the handle 1 and air supply passage 7. branch pipe 8 leads from the passage 7 to a reducing valve 9 by means of which the air inthe interior of the liquid reservoir is maintained at a predetermined or adjustable pressure. The corver l0.of the reservoir is suitably clamped down by screw 11, or the reservoir. is otherwise made pressure-tight for this purpose. Alternatively the pressure-feed of the li uid may be obtalned by the head of liquid, t e reservoir then being referably fixed at a suitable height and exibly` connected to the apparatus.

For the control of the liquid at the delivery port or nozzle 5 I employ the usual pin valve 12 which would be manipulated by a lever, preferably the usual finger lever 2 designed to control both the air valve and the pin valve.

The delive port for the air, surrounds the liquid disc arge ort 5, but in place of the usual construction esigned for only a narrow air passage around the liquid discharge port I provide a series of opemngs 13 so that the air will be divided up into a number of jets, which, impinging on the liquid from diiferent radial points tend to draw out the li uid in lines and splashes.

t is very important, however, to secure a uniform current of air around the discharge tip, and to effect this I provide within the air cap or nozzle an equalizing compressed air chamber 14 and a series of inner outlets from this, which delivers the air to the outer port at a practically uniform pressure over the entire area of the discharge port.

Slight clearances 15, where the nipple 16 and cap 17 are connected also assist 1n pressure` ualization and distribution of the compresse air at the outlet.

In certain cases the cap 17 may be exthe liquid emerging from the orifice. That' tended so as to form an annular port 18 surrounding the liquid delivery nozzle, and the ports 13 may also be merged to form anfan-v nular delivery port, but it is m'ostimportant that the partial Iseparation of the jets be maintained right up to the time of their striking is to say, the arrangementJ of jets around the orifice is symmetrical but the jets mustnot be merged into a single annulus of even pressure; the jets must in effect remain distinct or must form symmetrically arranged zones of comparatively high velocity or pressure to eect the tearing of the emerging jet into threads. Such arrangements are referred to hereinafter as separate jets.

The' compressed air may be supplied to the a paratus shown at a pressure in Ithe neigh ourhood of 20 to 301bs. per square inch, but the pressure in each case will olf course depend uponthe design of the apparatus and the nature of the liquid. Using a liquid of the nature of a varnish paint, the reducing valve 9 might be set to give a pressure in the neighbourhood of 10 lbs. per square inch. In operation the liquid emerging from thel nozzle is drawn out by the converging streams 'of air into threads or strings which fall upon the surface being treated with surprisingly uniform decorative effect but in a peculiar diversity of thickness and arrangement as roughly indicated in Fig. 2."

The same surface may be treated rst with liquid of one colour and subsequently with a different colour or different colours and a i variety of effects may Athus 'be obtained for many diierent purposes. It is, to be understood that the expression air includes al1 suitable gases or gaseous mixtures.

I claim In an apparatus for producing a decorative ei'ect of lines and splashes,v comprising a liquid reservoir, a nozzle, a passage connecting said reservoir and nozzle to deliver a liquid `under pressure from. the reservoir through the nozzle, means arranged annularly with respect to the nozzle for delivering a series of independent jets of air under pressure in substantial parallelism with the liquid delivery from the nozzle, a reducing valve, and aconnection to supply compressed air to said reservoir through said reducing valve to maintain a determinablepressure upon the liquid in the reservoir.

In testimony whereof I atlix my signature. CLES LAURENCE BURDICK.-

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