U.S. patent number 3,797,747 [Application Number 05/291,403] was granted by the patent office on 1974-03-19 for device for aspirating and admixing additives into a stream.
This patent grant is currently assigned to Firma Hano Grohe KG. Invention is credited to Gunter Buzzi, Werner Lorch.
United States Patent |
3,797,747 |
Buzzi , et al. |
March 19, 1974 |
DEVICE FOR ASPIRATING AND ADMIXING ADDITIVES INTO A STREAM
Abstract
The additives are aspirated and admixed into a stream of liquid
by means of an injector having a main bore, increasing in width in
the flow direction, and suction bores communicating with the main
bore. A liquid-return-flow interrupter is arranged at the inlet
side of the injector and is in the form of a free jet air chamber
communicating with the open air through corresponding openings and
adapted to be bridged by the liquid concentrated into a fine jet by
a nozzle bore. An acceleration chamber, converging in the flow
direction, is arranged at the inlet end of the nozzle bore whose
outlet end communicates with the free jet air chamber at the inlet
side of the latter. An apertured disc is positioned at the inlet
side of the acceleration chamber and is formed with a plurality of
bores therethrough for flow of liquid to the acceleration
chamber.
Inventors: |
Buzzi; Gunter
(Schiltach/Schwarzwald, DT), Lorch; Werner
(Schramberg, DT) |
Assignee: |
Firma Hano Grohe KG
(Schillach/Schw., DT)
|
Family
ID: |
5820547 |
Appl.
No.: |
05/291,403 |
Filed: |
September 22, 1972 |
Foreign Application Priority Data
|
|
|
|
|
Sep 25, 1971 [DT] |
|
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2147931 |
|
Current U.S.
Class: |
239/311; 239/335;
239/318; 239/428.5 |
Current CPC
Class: |
E03C
1/046 (20130101) |
Current International
Class: |
E03C
1/04 (20060101); E03C 1/046 (20060101); A62c
005/04 () |
Field of
Search: |
;239/310,311,318,335,428.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Knowles; Allen N.
Attorney, Agent or Firm: McGlew and Tuttle
Claims
What is claimed is:
1. In a device for aspirating and admixing additives into a stream
of liquid by means of an injector having a main bore, which
increases in width in the flow direction, and suction bores
communicating with the main bore, and a liquid-return-flow
interrupter arranged at the inlet side of the injector, in the form
of a free jet air chamber communicating with the open air through
corresponding openings and adapted to be bridged by the liquid
concentrated into a fine jet by a nozzle bore having a discharge
end spaced axially from the inlet side of the injector by the
interposed free jet air chamber, so that the fine jet traverses the
free jet air chamber in laterally unconfined condition, the
improvement comprising, in combination, means forming an
acceleration chamber, converging in the flow direction, arranged at
the inlet end of said nozzle bore which latter communicates with
said free jet air chamber at the inlet side of said free jet air
chamber; and an apertured disc positioned at the inlet side of said
acceleration chamber and formed with a plurality of passage bores
therethrough.
2. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 1, in which the
diameter of the passage bores of the apertured disc is less, by one
third, than the axial length of said passage bores.
3. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 1, including means
forming a dynamic pressure chamber interposed between said
acceleration chamber and said apertured disc; the internal diameter
of said dynamic pressure chamber being greater than the entrance
diameter of said acceleration chamber, and the axial length of said
dynamic pressure chamber being substantially equal to the axial
thickness of said apertured disc.
4. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 1, including a sleeve
having said nozzle bore formed therethrough; a second chamber
adjacent the outlet end of said nozzle bore and having a conical
internal periphery converging in the flow direction; the inlet side
entrance diameter of said second chamber being at least two times
larger than the outlet end terminal diameter of said sleeve; said
second chamber communicating, on its outlet side, with a concentric
bore forming at least part of the main bore of said injector; and
means forming a cavity communicating with the outer air through
openings and forming part of said free jet air chamber; said second
chamber communicating, on its inlet side, with said cavity.
5. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 4, in which the axial
length of said second chamber is at least 15mm.
6. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 1, including a
laminator arranged concentrically in said acceleration chamber and
having an external form converging in the flow direction.
7. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 6, in which said
laminator is a substantially conical body defining, with the
interior surface of said acceleration chamber, an annular flow
passage; the angle of divergence of said laminator being larger
than the angle of divergence of said accelerating chamber, so that
the cross-sectional area of said annular flow passage decreases at
least substantially continuously in a direction toward said nozzle
bore.
8. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 7, in which said
laminator is a drop-shaped body.
9. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 6, in which said
laminator is formed with an axial bore extending centrically
therethrough.
10. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 6, including a sleeve
enclosing said means forming said acceleration chamber; said
laminator having a fastening element on its inlet end and being
fixed in said sleeve, concentrically and detachably, by a holder
engaging said fastening element and formed with a plurality of
axial passages therethrough.
11. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 10, in which said
fastening element is a center stud.
12. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 10, in which said
fastening element is a hollow tenon.
13. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 10, in which said
holder is disc-shaped.
14. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 10, in which said
holder is star-shaped.
15. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 1, including a sleeve;
and an exchangeable tubular piece inserted into said sleeve and
having said acceleration chamber and said nozzle bore formed
therein.
16. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 15, in which said
tubular piece is made of synthetic material.
17. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 16, including a
laminator positioned concentrically in said acceleration chamber
and having an exterior shape converging in the flow direction; said
laminator being made of synthetic material.
18. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 1, in which said
injector main bore, adjacent the outlet side of said free jet air
chamber, has a diameter approximately equal to the outlet diameter
of said nozzle bore; said suction bores communicating radially with
said main bore; the diameter of said main bore, in the zone of said
radial suction bores, having a stepwise change to a larger
diameter.
19. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 18, in which said main
bore, adjacent the outlet side of said free jet air chamber, has a
diameter slightly larger than the outlet diameter of said nozzle
bore.
20. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 1, in which said
injector comprises a tubular element of synthetic material
interchangeably inserted into a metallic tube.
21. In a device for aspirating and admixing additives into a stream
of liquid, the improvement claimed in claim 20, including a sleeve
having said nozzle bore and said acceleration chamber formed
therein; said sleeve and said metallic tube being threadedly
connected to each other in the zone of said free jet air chamber.
Description
FIELD AND BACKGROUND OF THE INVENTION
This invention is directed to a device for aspirating and admixing
additives into a stream of liquid by means of an injector having a
main bore increasing in width in the flow direction and suction
bores communicating radially with the main bore. A
liquid-return-flow interrupter, in the form of a free jet air
chamber, communicating with the open air through openings, and
adapted to be bridged by the liquid which is concentrated into a
fine jet by a nozzle bore, is arranged on the inlet side of the
injector.
Such devices serve, for example, to admix dosed quantities of
liquid bath-water additives from a reservoir into the water jet of
a shower. The free jet air chamber is provided to assure that, when
water flows back from the shower conduit, no additive is aspirated
into the pipe line so that it would pass into the main water supply
system.
In a known device of this type, the means provided for the
generation of the free jet, which latter has to bridge the length
of the chamber with a minimum of losses, are too unfavorable to
assure a perfect bridging of a length of the chamber as prescribed
by the technical standards for free jet air chambers, and still
obtain, on the outlet side of the chamber, a sufficiently strong
suction effect. In addition, this known device permits only the use
of entirely back-flow-free orifices, and is not usable with shower
heads finely dividing the water jet.
SUMMARY OF THE INVENTION
The invention is directed to the problem of improving a device of
the mentioned type by appropriate measures so that, on the one
hand, a free jet path of at least 20 to 25 mm, which is a length
complying with the present standards, bridges the free jet air
chamber at normal water pressure without losses and, on the other
hand, a good suction effect of the injector is assured despite the
inevitable backwash when shower heads finely dividing the water jet
are used.
In accordance with the invention, this problem is solved by
providing an acceleration chamber, converging in the flow
direction, at the inlet side of the nozzle bore which leads into
the free jet air chamber, and by providing an apertured disc
arranged on the inlet side of the acceleration chamber and formed
with a plurality of bores or passages therethrough.
This simple measure results in a very strong acceleration and, at
the same time, homogenization and suppression of turbulence of the
water jet, with the effect that, even at a relatively low water
pressure, an entirely loss-free bridging of a free jet air chamber,
whose length complies with the present day standards, is assured
and a sufficiently strong aspiration of the admixture is
obtained.
In order to assure a particularly good and loss-free bridging of
the free jet air chamber by the concentrated liquid jet, it is
advantageous to dimension the passage bores in the apertured disc
so that their diameter is smaller than their axial length.
Especially in cases where the length of the acceleration chamber
cannot be but very small, it is important to arrange, between the
acceleration chamber and the apertured disc, a dynamic-pressure
chamber whose diameter is larger than the diameter of the entrance
to the acceleration chamber, and whose axial length is
approximately equal to the thickness of the apertured disc.
Particularly during the phase of generation of the jet which has to
bridge the free jet air chamber, for example, when turning on the
water supply for the aspiration device, there is a danger or
possibility that a part of the supplied liquid will accumulate in
the free jet air chamber and perhaps escape and trickle off. In a
preferred embodiment of the invention, this danger is eliminated by
providing a chamber adjacent to the nozzle bore at the outlet end
thereof and converging conically in the flow direction. The inlet
side entrance diameter of this chamber is at least two times larger
than the outlet side terminal diameter of a sleeve defining the
nozzle bore. The chamber is at least 15 mm long, leading, on its
outlet side, into a concentric bore provided in the injector, and
communicating, on its inlet side, with a cavity which communicates,
in turn, with the outer air through openings.
In another embodiment of the invention, the mentioned danger may be
avoided by providing a laminator arranged concentrically in the
acceleration chamber and also converging or tapering in the flow
direction. Advantageously, the laminator is a drop-shaped or
conical body with a rounded rear end, and its angle of divergence
is larger than the angle of divergence of the acceleration chamber,
so that the resulting decrease of the passage section is, at least
approximately, continuous in the direction of the nozzle bore. This
conformation advantageously permits obtaining not only a necessary
flow velocity and a homogenous jet in the free jet air chamber but
also a liquid flow entirely free from turbulence, which is of great
importance for the bridging of free jet air chambers of greater
length.
In another advantageous embodiment of the invention, the laminator
is provided with a central axial through bore or passage. The
generation of the jet in the nozzle bore is thereby very favorably
influenced. It has been proved, by practical tests, that this
measure assures a substantially increased independence of the
actual or necessary water pressure in the supply pipe, so that,
even with a low pressure, not only a loss-free bridging of the free
jet air chamber is obtained but also a sufficient suction effect in
the injector. Another advantage is the absence of the apex on the
conical body of the laminator, which apex always is exposed to
mechanical damage in stock keeping or, in other words, the fact
that, for the time prior to its mounting into the acceleration
chamber, the laminator is more immune to mechanical damage.
In accordance with another favorable feature of this embodiment,
the laminator is fixed to the sleeve defining the acceleration
chamber, on the inlet side concentrically and detachably, by means
of a centric stud or hollow tenon, to a disc-shaped or star-shaped
holder which is provided with several axially extending bores or
passages therethrough.
The acceleration chamber and the nozzle bore advantageously are
formed in a tubular piece which is inserted into the sleeve and
which, preferably, is made of a synthetic material.
All of these measures result, on the one hand, in a less expensive
and more simple manufacturing operation and assembly operation and,
on the other hand, in considerable advantages with respect to
maintenance of the device, the use of synthetic material
effectively reducing lime deposits or other contamination.
It is also important, for the construction of the device of the
invention, that the diameter of the nozzle bore adjacent to the
inlet side of the free jet air chamber is approximately equal to or
only slightly larger than the diameter of the bore of the injector.
The bore of the injector, in the zone of the radial suction bores
through which the additive is aspirated, is widened by a step or
shoulder, and the radial injector bores lead outwardly into an
annular groove which communicates with the suction tube of the
reservoir containing the admixture liquid. Thereby, on the one
hand, a maximum suction effect is assured and, on the other hand,
there is obtained the manufacturing advantage that, on the outlet
side, the injector nozzle can be cylindrical.
Advantageously, the injector nozzle is formed in a tubular piece of
synthetic material which is interchangeably mounted in a metallic
tube. The tubular piece forming the injector nozzle, and the sleeve
forming the nozzle bore, as well as the acceleration chamber, are
disengageably threaded together in the zone of the free jet air
chamber.
In the outlet part, beyond the inventive device, the aspirated
additive intermixes with the water. Moreover, in this part, an
intermediate zone, free from dynamic pressure, is formed, and a
shower head, producing a certain backwash, can be connected without
difficulty thereto and perform its function of dividing the water
stream into a multitude of fine jets in the same efficient manner
as a shower head to which the inventive device has not been
connected.
An object of the present invention is to provide an improved device
for aspirating and admixing additives into a stream of liquid by
means of an injector.
Another object of the invention is to provide such a device
producing a free jet path of at least 20 to 25mm in length.
A further object of the invention is to provide such a device
producing a good suction effect of an injector in spite of the
inevitable backwash when shower heads finely dividing the water jet
are used.
Another object of the invention is to provide such a device
including an acceleration chamber on the inlet side of a nozzle
bore communicating with the inlet side of a free jet air
chamber.
A further object of the invention is to provide such a device
including an apertured disc arranged on the inlet side of the
acceleration chamber and formed with a plurality of bore or
passages therethrough.
For an understanding of the principles of the invention, reference
is made to the following description of typical embodiments thereof
as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a longitudinal sectional view of a shower head with an
injector nozzle, a reservoir for additives, a free jet air chamber
and an acceleration chamber embodying the invention;
FIG. 2 is a longitudinal sectional view of an acceleration chamber
with a laminator of a different shape;
FIG. 3 is a right hand elevation view of FIG. 2;
FIGS. 4 and 5 are longitudinal sectional views of the acceleration
chamber and of an apertured disc positioned in advance thereof;
and
FIG. 6 is a longitudinal sectional view of a variant of the
embodiments of the invention shown in FIGS. 1 through 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, while FIG. 1 illustrates a complete shower head
with a complete device embodying the invention for aspiration and
admixing additives into shower-bath-water, the other figures
represent only parts necessary to the explanation of the respective
different embodiments.
Referring first to FIG. 1, and as alike in all other embodiments,
the embodiment of FIG. 1 includes a shower head 1 with an
adjustable sprinkling plate 2, shower head 1 being joined to a ball
pivot 3 which is fixed to an angled pipe 4 mounted in a tubular
head 5 of a liquid reservoir 6. Reservoir 6 contains liquid soap
which is aspirated through a suction pipe 7 and a check valve 8
into head 5. Reservoir 6 and head 5 are interconnected with each
other by a bayonet joint 9.
A metallic sleeve 10 is located in tubular head 5 of reservoir 6,
sleeve 10 being secured in head 5 through a thread 11 and
terminating in a flange 12. The sleeve includes a cylindrical
insert 13 of synthetic material which is formed with a through-bore
consisting of two parts 14 and 15 of different diameter. The
diameter of the part 15, toward the outlet side, is larger than
that of the part 14. The bores 14 and 15 act in the nature of an
injection nozzle. At the step 16 between the two different diameter
bores 14 and 15, several radially extending suction bores are
formed to connect the interior of the bore 14-15 with a common
annular groove 18 formed in the outer periphery of insert 13.
Groove 18 communicates, through a plurality of radial bores 19
through sleeve 10, with an annular groove 20 formed on the outer
periphery of sleeve 10, and further, through a bore 21 provided in
the bottom part of head 5 and through check valve 8, with suction
tube 7 of reservoir 6.
The shoulder 16 at the junction of bores 14 and 15 produces a sort
of Venturi tube suction or aspirating effect so that, when water is
flowing through bores 14 and 15 in the direction of arrow 22,
liquid soap is aspirated from reservoir 6 and admixed with the
water. In order not to disturb this suction effect, the inside
diameter of angle pipe 4 and that of the bore through ball pivot 3
are intentionally at least twice the size of the diameter of bore
15.
A further sleeve 24 is held against flange 12 of sleeve 10 by a
capscrew 23 whose inner diameter is substantially larger than the
maximum outer diameter of sleeve 24. The inlet end 25 of sleeve 24
is connected to a water supply pipe which has not been shown.
Sleeve 24 comprises an insert 26 of synthetic material which is of
cylindrical form on its external surface and which is formed, at
its inlet end, with a cylindrical bore 27 of relatively large
diameter and, at its outlet end, with a cylindrical nozzle bore 28.
The diameter of nozzle bore 28 is substantially smaller than that
of bore 27.
The cavity 29, between bores 27 and 28, is of frustoconical form
and serves as an acceleration chamber for the liquid flowing
therethrough. A streamline body 31, of generally conical shape and
with a hemispherical head 30, is located in chamber 29 and the
distance of the conical surface of body 31, which terminates at a
point, from the converging inner surface of insert 26, increases
continuously along its entire length in the direction 22 of the
flow. Streamline body 31 serves as a laminator eliminating
turbulence and producing an homogenous water jet issuing from
nozzle bore 28 with high velocity.
At its outlet end, nozzle bore 28 leads into a free jet air chamber
33 located in the outlet part 32 of sleeve 24. Free jet air chamber
33 communicates, through several radial bores 34 and through cavity
35 formed between the outer circumference of sleeve 24 and the
inner surface of cap screw 23, with the outer air. Considered in
the axial direction, free jet air chamber 33 is limited on one side
by the frontal surface 36 of insert 13 and, on the other side, by
the frontal surface 37 of insert 26.
The structural parts are arranged so that nozzle bore 28 and bore
14 of the injector nozzle are exactly coaxial, the diameter of bore
14 being only slightly larger than that of nozzle bore 28, with the
difference being about 0.1 to 0.3 mm. The distance between frontal
surface 36 and frontal surface 37 is at least 20mm and must be
freely bridged by the water jet discharged from nozzle bore 28 and
entering bore 14. Owing to the small difference in diameter between
nozzle bore 28 and bore 14, there is practically no pressure loss.
This is of great importance for the suction effect desired for
aspirating the liquid soap out of reservoir 6.
Streamline body 31 is fixed, by means of a stud 38, to a flange 39
formed with several passages or bores 40 through which water
entering in the direction of arrow 22 passes into acceleration
chamber 29. Flange 39 of streamline body 31 is secured in sleeve 24
by an annular screw 41 so that streamline body 31 is positioned, in
acceleration chamber 29, exactly concentric with the latter.
Another embodiment of the streamline body is shown in FIGS. 2 and
3. In these figures, streamline body 31' differs differs from
streamline body 31 merely by the fact that it is formed with a
central axial bore 42 and does not converge in a point.
It should be pointed out that there is, of course, no necessity to
provide bores 14 and 15, nozzle bore 28, acceleration chamber 29
and bore 27 in an exchangeable or interchangeable insert 13 or 26.
On the contrary, these bores or cavities may, with the same good
functional result, be formed directly in the sleeve 10 or the
sleeve 24 but, in view of deposits and contamination, as well as
the necessary maintenance, the embodiment illustrated in the
present example is preferable.
It should furthermore be noted that the angle of divergence .alpha.
of frustoconical acceleration chamber 29 is smaller than the angle
of divergence .beta. of streamline body 31 or 31', so that the
passage in acceleration chamber 29 increases, in an at least
approximately continuous manner, in the flow direction along the
surface of streamline body 31 or 31'.
In the embodiments of the invention shown in FIGS. 4 and 5, the
acceleration chambers are substantially shorter, in the axial
direction, than the acceleration chamber 29 of the embodiment shown
in FIGS. 1 and 2. Also, acceleration chambers 29' and 29" of FIGS.
4 and 5, respectively, are not provided with a streamline body 31
or 31'.
In the embodiments of FIGS. 4 and 5, the same sleeve 24 is used as
is used in the embodiment of FIG. 1. Consequently, with the length
of the inserts 26' or 26", of synthetic material, being
predetermined, and with the acceleration chambers 29' or 29" being
shorter in the axial direction, the nozzle bores 28' or 28" must
necessarily be of greater length in the axial direction.
Fortunately, the length of nozzle bores 28' or 28" does not
influence substantially the quality of the generated concentrated
water jet which has to bridge the free jet air chamber 33. Instead,
tests have proved that, for a nozzle bore 28' or 28", a length
which is greater than its diameter by approximately one third, as
is the case with the nozzle bore 28 in FIG. 1, is entirely
sufficient.
On the other hand, in the embodiments of the invention shown in
FIGS. 4 and 5, it is important to provide a cylindrical dynamic
pressure chamber 45 or 45', respectively, adjacent to the
associated acceleration chamber 29' or 29" on the inlet side of the
latter, and enclosed by an apertured disc 46 or 46' formed with a
plurality of cylindrical passages or bores 47 or 47' which are
arranged in the same manner as are the bores or passages 40 in
flange 39 of streamline body 31 or 31' of the embodiment of the
invention shown in FIGS. 1 and 2. While the bores 47 in apertured
disc 46 have axes parallel to each other, the axes of bores 47' of
apertured disc 46' converge at an acute angle .gamma. corresponding
approximately to the conical convergence of the acceleration
chamber 29".
In the embodiment of the invention shown in FIG. 6, the
acceleration chamber 50, which also is preceded by an apertured
disc 51 with a plurality of bores or passages 52 therethrough, is
also of conical form converging in the flow direction. The insert
53 in which acceleration chamber 50 and nozzle bore 54 are formed,
is mounted in a sleeve 55 and pressed, by apertured disc 51
threaded into sleeve 55, against an annular rim or shoulder 56 in
the interior of sleeve 55. Insert 53 is formed with a conical
projection 57 in which is formed the cylindrical nozzle bore 54 and
at least part of acceleration chamber 50, projection 57 extending
freely into a cavity 58 of sleeve 55. Cavity 58 communicates with
the outer air through openings 59. Adjacent to radial openings 59,
in the flow direction 52, sleeve 55 is provided with a threaded
flange 60 onto which a cap screw 61 is threaded. The inner diameter
of cap screw 61 is substantially larger than the outer diameter of
sleeve 55, so that an annular frontally open cavity is formed in
the zone of radial openings 59 between the circumference of sleeve
55 and the inner surface 62 of cap screw 61.
Cap screw 61 joins sleeve 55 to a cylindrical body 63 which, in
turn, is threaded, by means of a thread 64, into tubular head 5 of
reservoir 6. Body 63, or the elements thereof, have functions
similar to the functions provided, in FIG. 1, by sleeve 10, insert
13, bores 14 and 15, suction bores 17, 19 and annular groove 20.
Cap screw 61 embraces an annular flange 65 of cylindrical body 63,
and body 63 is centered, by its conical projection 66, in a
conforming set of threaded flange 60.
Unlike those embodiments shown in FIGS. 1 through 5, where nozzle
bores 28, 28' or 28" are spaced from the frontal surface 36 by
cylindrical cavity 33 in sleeve 24, in the embodiment of FIG. 6,
nozzle bore 54 terminates in the plane of frontal surface 66' of
body 63. The free jet air chamber is formed by a cavity 68 in
cylindrical body 63 and which converges conically in the flow
direction 22. The diameter of the entrance orifice of cavity 68 is
approximately three times larger than the terminal diameter of
projection 57 in which is formed nozzle bore 54, so that there is a
sufficiently large communication passage between cavity 68, in
cylindrical body 63, and the cylindrical cavity 58, in sleeve
55.
Between cavity 68, which is 20 mm long in the axial direction, and
bore 14, there is provided a conical intermediate chamber 69 which
receives the water jet from nozzle bore 54 and directs the same
into bore 14. Bore 14, and also bore 15' which, in the embodiment
of FIG. 6, is conical, are formed directly in cylindrical body 65
and not, as in the embodiments shown in FIGS. 1 through 5, in an
insert 13 of synthetic material. However, the function is the same
as in the embodiments of FIGS. 1 through 5.
It should be noted further that, as distinguished from the
embodiments of FIGS. 4 and 5, in the embodiment of FIG. 6, no
dynamic pressure chamber 45 or 45' is provided between apertured
disc 51 and acceleration chamber 50. Instead, acceleration chamber
50 is substantially longer and its diameter, on the inlet side, is
larger. However, the arrangement of the apertured disc 51 with the
passages of bores 52 directly before acceleration chamber 50 is of
importance in this embodiment also. Apertured disc 51, as
mentioned, is threaded into the inlet part of sleeve 55.
Numerous test have shown that all of the described embodiments
assure almost equally good operational results. However, the
embodiment of FIG. 6 is preferable by reason of its simple
construction. In this embodiment, it is also possible to
manufacture apertured disc 51, insert 53 and cylindrical body 63,
formed with the water-conducting bores 14 and 15, of synthetic
material, thereby largely avoiding lime deposits or similar
contamination.
It furthermore is important, with respect to the thickness of the
apertured disc 46, 46' or 51, to dimension the passages or bores
47, 47' or 52, respectively, so that their diameter is smaller than
their axial length. In the present examples, the diameter of these
passages or bores is half the length thereof.
While specific embodiments of the invention have been shown and
described in detail to illustrate the application of the principles
of the invention, it will be understood that the invention may be
embodied otherwise without departing from such principles.
* * * * *