US2812213A - Spray nozzle - Google Patents

Description

United States Patent 2,812.11: SPRAY NOZZLE James Aaliedeyclevelaud, Ohio Application February 16, 1956, Serial No. 565,869 l ciaim. crass-140 The present invention relates generally as indicated'to a spray nozzle for spraying liquids such as paint, fuel, etc. The commercial form of spray nozzle which is most frequently used in the spraying art comprises an apertured plate which is formed in one face with a drilled hole having a rounded bottom and which rounded bottom is intersected by a discharge slot formed on the opposite face of said plate. Considerable difficulty has been encountered in accurately forming such spray nozzles, and,

as a consequence, a large percentage of rejects is encountered in the manufacture of such nozzles.

It is an object of this invention to provide an entirely new form of spray nozzle by which better atomization is obtained than known heretofore.

It is another object of this invention to provide a spray nozzle design which lends itself to mass production with uniform accuracy and practical elimination of rejects as aforesaid.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of

but one of a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

Figs. 1 and 2 are side and end elevation views, respectively, of a typical spray nozzle;

Fig. 3 is a cross-section view taken substantially along the line 3-3, Fig. 2, to show a well known form of spray nozzle construction;

Fig. 4 is a fragmentary cross-section view of a nozzle constituting the present invention;

Fig. 5 is a longitudinal cross-section view of a partly finished nozzle member;

Fig. 6 is a longitudinal cross-section view showing the finished nozzle member as formed with oblique end faces at one end;

Fig. 7 is an enlarged fragmentary cross-section view showing a pair of nozzle members in converging operative relation providing for collision of the liquid streams flowing therethrough and providing a diverging discharge slot which determines the width of the spray pattern; and

Fig. 8 is an elevation view as viewed downwardly from the top of Fig. 7.

In order that the features of this invention may be more readily understood, there .is shown in Fig. 3 a well known and conventional type of spray nozzle 1 as used, for example, in the paint spraying field. Said nozzle 1 is in the form of a flanged cup which is detachably mounted on the end of a spray gun 2 as by means of the nut 3 as best shown in Figs. 1 and 2.

Said nozzle 1 is formed with a rounded bottom recess 2,812,213 Patented Nov. 5, 1957 4 which is open on its rear side and is formed with a transverse slot 5*on its front side, the bottom of which slot 5 intersects therounded bottom of said recess whe'r'eby liquid supplied under pressure into the nozzle 1 is subjected tolateral constrictionand-'turbulence in recess 4,

and thence is discharged through the diverging slot -5 as a spray '6 having the desired form as determined by the size and shape ofsuch slot 5.

'As'evident, it requires painstaking effort to accurately respect to the axis of the recess and so that the size of the opening 7 at the intersection is accurate.

It has been found that nozzles 1 of the type shown in Fig. 3 are extremely diflicult to produce on a mass production basis because a relatively large percentage of rejects are encountered due to slight inaccuracies which seriously aifect the performance of the nozzle.

' In the present improvements, the nozzle body 10 itself may be of the same form as the prior nozzle 1 except that it is drilled as shown to provide two converging bores 11 which come together adjacent the front face of the nozzle, and said front face may be counterbored or otherwise formed as at 12 to clear the sprayed liquid.

Inserted into the respective bores 11 are tubular nozzle members 14 which may easily be formed of desired hard, abrasion-resisting material, such as tungsten carbide, silicon carbide, or synthetic sapphire. As best shown in Figs. 5 and 6, each nozzle member 14 comprises simply a tubular body having a central longitudinal passage 15 therethrough and one end of each member 14 is formed with a double bevel or adjacent oblique faces 16 and 17.

If desired, these simple and accurately formed tubular nozzle members14 are press-fitted into the respective bores 11 so that the oblique faces 17 thereof abut one another, whereby the two streams of liquid flowing therethrough collide with each other to produce a highly turbulent action in the zone marked 18 in Fig. 7 and the other oblique faces 16 form a discharge slot 19 therebetween. The beveled faces 16 and 17 may be easily formed by machining or grinding to very close tolerances Without holding any length dimensions or depth dimensions to close tolerances as required in the Fig. 3 nozzle.

If the tubular nozzle members 14 are installed by pushing forward in the respective bores 11, suitable plugs 20 may be inserted in the holes as shown.

The bores 11 need not extend all the way through the nozzle body 10, but, instead, one nozzle 14 may be fitted-in one bore 11 and pushed beyond its final terminal position so that the other may be installed from the front of the nozzle 10 and then both nozzle members 14 may be shoved forwardly from the rear of the nozzle body 10 until the oblique faces 17 abut each other to thus cause collision of the respective streams of liquid and discharge of the colliding liquid streams through the diverging generally oval-shaped slot 19 which is of Width as determined by the angle A between the diverging end faces 16.

The convergence of the streams of liquid produces better atomization because of the greater turbulence, and the present nozzles 14 can readily be made uniformly accurate with reference to the diameters of the passages 15 through the nozzle members and the angles B and C of the oblique intersecting faces 16 and 17 which respectively diverge and abut when installed.

It is to be understood that, instead of press-fitting the tubular nozzle members 14 in place in the nozzle body 10, they may be simply sliding fits in the respective 3. bores 11 and be held in place by suitable set screws or else soldered or brazed in place.

With this invention, it has been found that, by varying the angle A of the diverging faces progressively from 110 to 15, the spray pattern will progressively become wider to say about 30 width at the base at a distance of 10" from the end of the nozzle. 1 I

For example, in the spraying vof lacquer, very fine atomization and a very thin fan-shaped spray field is obtained by bringing together two nozzle members 14, each having .020" diameter passages 15 therethrough at an included angle D of about 60 and providing a discharge slot 19 having an included angle A of 30.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:

In a spray nozzle, the combination of at least two tubular members; and a nozzle body in which said members are supported in converging relation to effect collision of streams of liquid flowing through said members; said members being formed with abutting and diverging end faces, the latter intersecting the converging passages of said members to define a discharge slot from which the colliding streams of liquid are sprayed in a pattern of width as determined by the angle between such diverging faces.

References Cited in the file of this patent UNITED STATES PATENTS 418,582 Monsanto Dec. 31, 1889 2,499,092 Burnam Feb. 28, 1950

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