Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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DESCRIPTION OF TOE INVENTION
The present invention relates generally to spray nozzles,
and more particularly, to spray nozzles of the type that
produce a hollow cone spray.
In such spray nozzles, a pressurized liquid stream is
introduced tangentially into a cylindrical whirl chamber to
impart a rapid swirling movement to the liquid, with the
resulting centrifical forces producing a spray of hollow,
conical or similar shape as it emerges from a discharge oft-
flee of the nozzle. The whirling movement of the liquid
creates an elongated hollow air core within the spray which
extends to the bottom of the whirl chamber. the lower end or
vortex of the air core can create significant wear to the
bottom of the nozzle body, and in some instances bore a hole
through the nozzle body in a relatively short time. twill
various whirl chamber designs have been proposed from minimize
in air core wear in such spray nozzles, these designs often
have not have been susceptibly to easy manufacture by convent
tonal techniques, such as plastic injection molding or metal
machining, and sometimes have adversely affected the spray
characteristics of the nozzle.
In addition to wear prevention considerations, for
example, it is important to design both the inlet orifice and
the whirl chamber such that the air core remains in centered
axial relation to the discharge orifice in order to achieve
uniform liquid distribution in the hollow spray pattern.
Because of unbalanced forces resulting from the tangential
introduction of liquid into the whirl chamber, there is a
tendency for the lower portion of the air core in the whirl
chamber to be shifted away from the axis of the discharge
orifice. Moreover, even small variations in the inlet orifice
or the bottom wall of the whirl chamber can the proper
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air core position, and -thus, the uniformity of the spray
pattern. While various approaches again have been proposed
for centering the elf core in the whirl chamber, such prior
designs in many instances have been objectlonal from the
standpoint of permitting excessive air core wear, as being
relatively costly to produce, or not being adaptable to
accommodate changes in size or capacity of the nozzle.
The problems of the prior art are overcome by the
present invention which provides a spray nozzle for product
lung a hollow conical liquid spray pattern having a centralalr core comprising a body formed with a whirl chamber
having a circular side wall and a bottom wall, the body
having an inlet passage for directing liquid in a substanti-
ally tangential direction into the circular whirl chamber,
means closing the top of the chamber and defining a circus
far spray discharge orifice disposed coccal with the
circular side walls of the whirl chamber, a post extending
upwardly from the whirl chamber bottom wall, the post having
a diameter of about one half the diameter of the whirl
chamber and extending upwardly to an elevation about level
wealth the upper perimeter of the inlet passage for guiding
pressurized liquid introduced into the whirl chamber from
the inlet passage in proper whirling direction about -the
circular side wall of the whirl chamber, and the post being
formed with a recess in the upper end thereof which has an
uninterrupted generally circular outermost perimeter and
which extends partially into the post in aligned relation-
skip to the axis of the discharge orifice for receiving the
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lowermost end of the air core of the whirling liquid within
the chamber for retaining the proper axial position of the
air core and whirling liquid without substantial diffusion
of the hollow cone spray pattern and for preventing damage
to the body from the air core and whirling liquid.
Other features and advantages of the invention
will become apparent upon reading the following detailed
description and upon reference to the drawings, in which:
FIGURE 1 is a top plan of an illustrative spray
nozzle embodying the present invention;
Fig. 2 is a vertical section taken in the plane of
line 2-2 in Fig. it and
Fig. 3 is a horizontal section taken in the plane
of line 3-3 in Fig. 2.
While the invention is susceptible of various
modifications and alternative constructions, a certain
illustrated embodiment thereof has been shown in the draw-
ins and will be described below in detail. It should be
understood, however, that there is no intention to limit the
invention to the specific form disclosed, but on the con-
tray, the invention is to cover all modifications, alter-
native constructions and
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equivalents falling within the spirit and scope of the invent
lion.
Referring now more particularly to the drawings, there is
shown an illustrative spray nozzle 10 embodying the present
invention. The nozzle 10 includes a main body 11 formed with
a cylindrical whirl chamber 12 and an inlet passage 14 extend- _
in tangentially and at a right angle to the cylindrical whirl
chamber 12. The inlet passage 14 preferably communicates with
a lower portion of the whirl chamber 12, entering the whirl
chamber at a point slightly above a bottom wall 13 thereof.
The nozzle body 11 in this instance includes an inlet connector
end 15 extending to one side thereof formed with an internally
threaded bore 16 in communication with the inlet passage 14
for coupling to the threaded end of a fluid supply line 18.
The body 11 has an internally threaded discharge end 19 which
receives the threaded end of an orifice cap 20 formed with a
discharge orifice 21 that is in coaxial communication with the
whirl chamber 12. The outer end of the orifice cap 20 may be
formed with appropriate means, such as circumferential
spaced ribs 22, which facilitate turning of the cap for tight-
eying and removal from the body 11.
The discharge orifice 21 of the illustrated cap 20 in-
eludes an inwardly tapered orifice section aye extending up-
warmly from the whirl chamber 12 and into communication with a
relatively short length, reduced diameter, cylindrical orifice
section 21b. The upper face of the orifice cap 20 is formed
with a downwardly and outwardly tapered portion 21c about the
periphery of the cylindrical orifice section 21b. As is known
in the art, the configuration of the discharge orifice 21 may
vary according to the spray angle and configuration desired,
and in the illustrated embodiment, the cap 20 is readily
removable and replaceable by unscrewing the cap from the
nozzle body 11.
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Pressurized liquid introduced into the supply line 18
will tangentially enter the whirl chamber 12 through the inlet
passage 14, causing a rapid swirling movement to be imparted
to the liquid in the chamber. us liquid continues to be
directed into the whirl chamber from the supply line, the
swirling liquid in the chamber will be expelled outwardly
through the discharge orifice 21 of the cap 20 in a centrally-
open, rotating stream at a sufficient velocity to form a
relatively thin, hollow cone spray 25, as indicated in Fig. 2.
The resulting air core within the hollow cone spray pattern
extends through the nozzle discharge orifice 21 and into the
whirl chamber 12 terminating in a lowermost vortex aye. The
uniformity of volume and the direction of the spray projection,
as is known in the art, is adversely affected if the axis of
rotation of the liquid, and thus the air core, is varied with
respect to the axis of the whirl chamber 12 and discharge
orifice 21.
in accordance with the invention, the nozzle body has an
axially disposed whirl chamber post extending upwardly from
the bottom of the whirl chamber, which assists in guiding
liquid introduced in the whirl chamber in the proper tangential
direction and which is formed with a recessed upper end that
retains the axial position of the swirling liquid within the
chamber and minimizes air core wear. To this end, in the
illustrated embodiment, the nozzle body 11 has an integrally
formed upstanding post 28 which extends from the bottom 13 of
the whirl chamber to an elevation about level with an upper
periphery aye of the inlet passage 14, as shown in Fig. 2,
such that the post extends substantially across one side of
the path of the liquid being introduced into the whirl chamber.
The illustrated post 28 is approximately one-half the diameter
of the whirl chamber 12, and the inlet passage 14, which may
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have a diameter up to oriole that of the whirl chamber, in
this case is of slightly smaller size. Pressurized liquid
introduced into the whirl chamber through the inlet passage 14
thereby moves about a common side of the post 28, as best seen
in Fig. 3, with the post tending to assist in guiding the
liquid stream in the proper direction.
In keeping with the invention, upper end of -the whirl
chamber post 28 is formed with a recess 29 which serves to
retain the air core of the swirling liquid coccal in the
whirl chamber so as to enhance the uniformity of the spray
output, while minimizing air core wear to the nozzle body 11.
The illustrated recess 29 has a concave spherical shape, with
an outer peripheral edge aye having a circular configuration
concentrically located with respect to the discharge orifice
21. While other shapes of recesses may be employed, the recess
29 preferably should have a continuously curved, uninterrupted
peripheral edge aye, which facilitates retention of the lower-
most vortex of the air core without disrupting the whirling
liquid or causing undue turbulence thereto.
In use of the nozzle of the present invention, it has
been found that the recessed upstanding whirl chamber post 28
will effectively maintain the proper axial position of the air
core without incurring significant air core wear. Moreover,
it has been found that the basic nozzle design may be easily
varied to accommodate different capacities without affecting
the improved wear and spray characteristics of the nozzle.
For example, it has been found that the same basic nozzle body
design may be utilized with different sized inlet passages 14
and with different orifice caps 20 while retaining all of the
advantages of the invention. With a standard nozzle body
design having the upstanding whirl chamber post extending to
an elevation about level with the upper perimeter of the inlet
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passage it, or slightly above such elevation, the same body
can be used for nozzles with incrementally larger or smaller
inlet passages.
It will be appreciated by one skilled in the art that the
nozzle body will accordingly lend itself to economical product
lion since variable size and capacity nozzles may be produced
by altering only the inlet passage. It will also be apprise-
axed that the nozzle body can be economically manufactured by
conventional techniques. While in the illustrated embodiment
a plastic injected molded nozzle body 11 has been shown with
an integrally formed upstanding whirl chamber post 28, it will
be understood that the nozzle body could be readily machined
from stock or a metal casting. Moreover, although the thus-
treated whirl chamber post is an integral part of the body,
alternatively it could be a separate and replaceable item,
fixed to the body by thread able engagement or the like.
From the foregoing, it can be seen that the whirl spray
nozzle of the present invention is relatively simple and
economical to produce, effectively controls air core wear and
position, and is adapted to accommodate design variations for
different inlet sizes and nozzle spray capacity.
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