US2318769A - Method of making nozzles - Google Patents

Description

y 1943- H. G. FREEMAN ETAL 2,318,769

METHOD OF MAKING NOZZLES Filed Nov. 6., 1941 I /v entor M, .ifiww Patented May 11, 1943 UNITED STATES PATENT OFFICE METHOD or' MAKING NOZZLES Howard G. Freeman and Frank Hencinski, Worcester, Mass., assignors to Rockwood Sprinkler Company, Worcester, Mass., a corporation of Massachusetts Application November 6, 1941, Serial No. 418,004 Claims. (01. 29-157) The present invention relates to methods of making fire extinguishing nozzle heads, and is more particularly concerned with the manufacture of fog generating nozzle heads having intersecting orifices, as described in the co-pending application of Freeman, Serial No. 418,003, filed of even date herewith.

The nozzle head described in the above-mentioned application operates on the principle of impinging streams of water which are broken up into a fine projected fog. The principal characteristic of these heads isthe use of passages, the center lines of which intersect at or very close to the exterior surface of the head. Impingement of the streams is, therefore, internal of the body of metal which constitutes the nozzle head. Nozzles of this type -have been found very satisfactory from the standpoint of adequate projection, fineness of break-up, and uniformity of distribution. The manufacture of the nozzle heads has, however, presented a diflicult problem, because of the necessity of forming passages at an angle to the surface.

The object ofthe present invention is to devise an improved method for making nozzle heads of this character, whereby the passages may be quickly and economically formed with the requisite precision. To this end, the present invention comprises the method hereafter described and particularly defined in the claims.

In the accompanying drawing, Fig. 1 is a sectional elevation of a nozzle head in process of manufacture, illustrating the improved method; Fig. 2 is a view similar to Fig. 1, showing the completed nozzle head; Fig. 3 is a 'side elevation of the completed nozzle; Fig. 4 is a diagram illustrating the application of the method to a nozzle head of difierent shape; and Fig. 5 is a sectional view of the completed nozzle head of Fig. 4.

The nozzle head shown in Figs. 2 and 3 is a portable head having a hollow body 6 with end faces 8 and I9. As shown in Fig. 2, the end faces are inclined from the center line, and as viewed inv Fig. 3. these faces are arcuate. Each of the faces 8 and ill is provided with a series of nozzles,

passages. As shown in Fig. 1, one of the ridge members is formed on the face 8 and another on the face 10, these members conforming to the curvature of theend faces. The passages which form the nozzles I2, l4 and I6 are then drilled through the body of metal. The drilling is perpendicular to the faces 20 and 22 of the ridge members. The drill centers are accurately spotted, and the drilling is preferably accomplished by the use of jigs, especially if a number of heads of the same type are to be manufactured. As shown in Fig. 1, the intersecting passages 24 form the center nozzles l2 of the head. The drilling may be done accurately because the drill is started with its axis perpendicular to the surface of the metal.

After drilling, the ridge members 18 are milled off. The milling is carried to a stage where the intersections of the center lines of the passages -24 lie in the surface of the head. If this machining is carried out with reasonable precision, the nozzles present a true elliptical appearance. As explained in the co-pending application above referred to, the tolerable deviation of the machined surface from the intersection of the center lines should generally not exceed 5% of the dimakes it possible to trim off the ridge members namely a center nozzle of large diameter, end

nozzles Id of medium size, and intermediate nozzles it of small size. Each nozzle is formed by two i tersecting drilled passages, so that for the completed head, twenty accurately drilled passages are required.

The body G'is originally formed, as shown in Fig. 1. with ridge members It which areV-shaped in section. These ridge members have walls 20 and 22 perpendicular to the center lines of the I8 with conventional milling machinery, and. to expose all of the nozzles atsubstantially the correct depth of cut, within the tolerances above mentioned.

The construction shown in Fig. 515 a nozzle head, for fixed installations, wherein a ring of nozzles 26 is formed around the cylindrical body 28, another ring of nozzles 30 is formed on a frusto-oonical surface, and a single nozzle 32 is formed at the end of the head. The method of manufacture is-shown in Fig. 4. The passages for the nozzles 26 are drilled in a V-shaped ridge member 34, which encircles the body; the pas sages for the nozzles 30 are drilled in a ridge member 36, which encircles the head near the end;,and the passages for the nozzle 32 are drilled in a small ridge member 38 at the end. The ridge members 34, 36 and 38 are then accurately machined on to expose the nozzles as ,in the construction previously described. It will be noted that the ridges 34 and 36 are formed on surfaces of revolution, and the ridge 38 is formed on the flat surface of the end of the nozzle. whereby the various ridges may be accurately trimmed ofi by the use of conventional milling machinery.

Having thus described the invention, we claim:

1. The method of making nozzle heads with intersecting nozzle orifices, which consists in forming a hollow metal body with a ridge having walls perpendicular to the center lines of the orifices, drilling through both walls of the ridge perpendicular thereto to form passages intersecting within the ridge, and machining off the ridge to a precise surface to expose the orifices adjacent their intersection.

2. The method of making nozzle heads with intersecting nozzle orifices, which consists in forming a hollow metal body with a ridge having walls perpendicular to the center lines of the orifices, drilling through both walls of the ridge perpendicular thereto to form intersecting passages, and machiningofi the ridge substantially to a surface which includes the intersection of the center lines of the orifices.

3. The method of making nozzle heads with sages, and machining off the ridge to a surface which does not deviate from the intersection of the center lines of the orifices by more than 5% of the orifice diameter.

4. The method of making nozzle heads with intersecting nozzle orifices, which consists in forming a hollow metal body with a ridge having walls perpendicular to the center lines of the orifices, drilling through both walls of the ridge perpendicular thereto to form intersecting passages, and machining off the ridge to a surface of revolution which includes the intersection of the center lines of the orifices.

5. The method of making nozzle heads having passages which intersect at the nozzle sur-- face to form orifices of substantially elliptical shape, which comprises forming a nozzle body with a ridge on the nozzle surface having walls perpendicular to the desired centerlines of the passages, drilling through the walls of the ridge on opposite sides thereof to form passages intersecting within the ridge, and thereafter cutting down the ridge to a surface which includes the intersection of the center lines of the passages intersecting nozzle orifices, which consists in 25 and lies substantially normal to the bisector forming a hollow metal body with a ridge having walls perpendicular to the center lines of the orifices, drilling through both walls of the ridge perpendicular thereto to form intersecting pasthereof.

HOWARD G. FREEMAN. FRANK HENCIN SKI.

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