Fluid flow regulator

A flow regulator for water or other fluids has a housing with an internal shoulder between its inlet and outlet. The shoulder faces the inlet and slidably supports an elastically deformable annular flow restrictor which cooperates with a centrally located stud to define an annular passage extending from the inlet to the shoulder and followed by an annular portion of the channel between a conically diverging stepped or roughened internal surface of the housing and a stepped or roughened conical external surfaces of a guide member which carries the stud. Deformation, and hence the flow restricting action, of the flow restrictor depends upon the pressure differential which is established by the conveyed fluid. The flow restrictor has a conical internal surface which tapers in a direction from the inlet of the channel toward the shoulder, and the radially outermost portion of the flow restrictor has axially parallel slots or holes which weaken the adjacent portion of the flow restrictor so that the latter is more readily deformable and can properly control the flow of fluid which is conveyed at a relatively low pressure.

BACKGROUND OF THE INVENTION 
The invention relates to fluid flow regulators in general, especially to 
flow regulators which can be installed in or used in combination with 
conduits for liquid media. More particularly, the invention relates to 
improvements in fluid flow regulators of the type wherein a housing 
defines a channel for the flow of a fluid from the inlet to the outlet of 
the channel and the housing is provided with a socket for a deformable 
flow restrictor which serves to regulate the quantity of fluid flowing 
through the housing per unit of time. The flow restrictor undergoes 
elastic deformation the extent of which is a function of the pressure 
differential that is established by the fluid. Such flow regulators are 
further provided with studs which are spacedly surrounded by the normally 
annular flow restrictors to define with the latter annular passages for 
the conveyed fluid. 
German Pat. No. 20 60 751 discloses a rather complex and expensive fluid 
flow regulator. In addition, the patented fluid flow regulator generates 
excessive noise and is incapable of regulating the flow of fluid with a 
high or even reasonably high degree of accuracy. 
German Pat. No. 26 16 566 discloses a modified fluid flow regulator which 
generates less noise than the aforedescribed patented flow regulator. 
However, this flow regulator exhibits the serious drawback that its flow 
regulating action is quite erratic when the pressure of conveyed fluid is 
relatively low. In other words, while the flow regulator operates 
satisfactorily when the pressure of conveyed fluid is high, the quantity 
of conveyed fluid per unit of time departs considerably from a desired or 
optimum quantity when the pressure of conveyed fluid drops. In addition, 
this flow regulator is likely to become clogged after a relatively short 
period of use if the conveyed fluid carries solid particles. 
OBJECTS OF THE INVENTION 
An object of the invention is to provide a fluid flow regulator which is 
constructed and assembled in such a way that its characteristic curve is 
more satisfactory than those of conventional fluid flow regulators 
irrespective of whether the fluid (such as water) is admitted at an 
elevated pressure or at a low or very low pressure. 
Another object of the invention is to provide a fluid flow regulator which 
is constructed in such a way that its reliability at low fluid pressures 
is just as satisfactory as, or at least approximates that, when the 
pressure of admitted fluid is high. 
A further object of the invention is to provide a fluid flow regulator 
which is less likely to be clogged with solid ingredients of conveyed 
fluids than heretofore known fluid flow regulators. 
An additional object of the invention is to provide a self-cleaning fluid 
flow regulator. 
Still another object of the invention is to provide a novel and improved 
flow restrictor for use in the above outlined fluid flow regulator. 
An additional object of the invention is to provide a novel and improved 
housing for the above outlined flow restrictor. 
A further object of the invention is to provide a novel and improved method 
of enhancing the elasticity of the improved flow restrictor. 
Another object of the invention is to provide a fluid flow regulator which 
generates little noise irrespective of whether the fluid is admitted at an 
elevated pressure or at a low pressure, which comprises a small number of 
simple and inexpensive parts, and which can be combined with existing 
stream regulators or like fluid flow controlling or influencing devices. 
An additional object of the invention is to provide the fluid flow 
regulator with novel and improved noise reducing means and with novel and 
improved means for regulating and maintaining the speed of conveyed fluid 
at a desired value or within a desired range. 
A further object of the invention is to provide a fluid flow regulator 
which can be used in connection with beverages and liquid or flowable 
foodstuffs without the danger of contaminating and/or otherwise affecting 
the desirable characteristics of foodstuffs. 
SUMMARY OF THE INVENTION 
One feature of the present invention resides in the provision of a fluid 
flow regulator which comprises a hollow housing defining a channel with a 
fluid-admitting inlet and a fluid-discharging outlet. The housing has an 
internal shoulder which surrounds a portion of the channel between the 
inlet and the outlet and faces the inlet, and the flow regulator further 
comprises an annular elastic flow restrictor which has an apertured 
portion which abuts the shoulder. The flow regulator further comprises a 
stud which is disposed substantially centrally of the channel and is 
surrounded by and defines with the flow restrictor an annular passage for 
the flow of fluid from the inlet toward the outlet. The cross-sectional 
area of the passage and the rate of fluid flow to the outlet vary in 
response to variations of fluid pressure and the resulting variations of 
the extent of deformation of the elastic flow restrictor. The 
aforementioned portion of the flow restrictor is preferably ring-shaped 
and has at least one aperture which extends in substantial parallelism 
with the direction of fluid flow from the inlet toward the outlet of the 
housing. As a rule, or at least in many instances, the ring-shaped portion 
of the flow restrictor will have a plurality of apertures, e.g., an 
annulus of apertures which are equidistant from each other in the 
circumferential direction of the flow restrictor. At least some of the 
apertures extend all the way through the ring-shaped portion. 
The apertures of the ring-shaped portion are or can be provided at the 
peripheral surface of the ring-shaped portion. For example, the apertures 
can constitute slots which extend inwardly from the peripheral surface of 
the ring-shaped portion. Each slot can but need not extend substantially 
radially of the ring-shaped portion. For example, the ring-shaped portion 
can be provided with between two and fifteen, preferably ten or close to 
ten apertures. As mentioned above, at least some of the apertures can 
extend all the way through the ring-shaped portion. At least one aperture 
can have a polygonal or at least partially circular cross-sectional 
outline. 
The flow restrictor can contain or can be made entirely of soft elastomeric 
material, such as silicone rubber. It is preferred to make the flow 
restrictor from a material which is compatible with foodstuffs, i.e., 
which will not affect the color, quality, taste and/or other desirable 
characteristics of foodstuffs. 
In accordance with a presently preferred embodiment, the flow restrictor 
has a substantially conical internal surface which is adjacent the passage 
between such flow restrictor and the stud. The diameter of the internal 
surface preferably decreases in a direction from the inlet toward the 
outlet of the channel in the housing. The length of the stud is or can be 
less than the axial length of the internal surface. In other words, the 
stud need not project beyond the inlet (counter to the direction of fluid 
flow from the inlet toward the outlet). 
The ring-shaped portion of the flow restrictor can be provided with a 
surface which abuts the shoulder in the housing. At least one aperture of 
the ring-shaped portion has or can have an end in the just mentioned 
surface of the ring-shaped portion, and such end of the at least one 
aperture is or can be bounded by a sharp edge. 
The flow regulator further comprises a guide member which is disposed in 
the housing substantially between the shoulder and the outlet and is 
adjacent (and preferably rigid or integral with) the stud. The external 
surface of the guide member is spacedly surrounded by and defines with the 
housing an annular portion of the channel. A radially outwardly extending 
flange of the guide member at the outlet of the channel has one or more 
openings through which the fluid flows on its way from the annular portion 
of the channel. The annular portion of the channel preferably diverges in 
a direction from the passage toward the flange. 
The internal surface of the housing around the annular portion of the 
channel and/or the external surface of the guide member can be scored, 
grooved, knurled, scratched and/or otherwise roughened. Moreover, the just 
mentioned internal surface of the housing and/or the external surface of 
the guide member can be stepped, preferably in such a way that it 
comprises a plurality of steps which extend in the circumferential 
direction of the flow restrictor. Each stepped surface can include 
substantially cylindrical first sections and annular second sections which 
alternate with the first sections and extend substantially at right angles 
to the direction of fluid flow in the annular portion of the channel. The 
first sections and the neighboring second sections of each stepped surface 
can define sharp annular edges or rounded annular edges. The cylindrical 
sections of each stepped surface can but need not have identical or nearly 
identical lengths. For example, at least two cylindrical sections of each 
stepped surface can have different axial lengths. The arrangement may be 
such that the axial length of each following first section (as seen in the 
direction of fluid flow in the annular portion of the channel) exceeds the 
axial length of the preceding first section. Alternatively, the axial 
length of each preceding first section can exceed the axial length of the 
following first section (again as seen in the direction of fluid flow in 
the annular portion of the channel). Each of the two confronting surfaces 
can be provided with a plurality of steps, and the steps of one of the 
surfaces can be staggered with reference to the steps of the other surface 
in the direction of fluid flow in the annular portion of the channel. The 
arrangement may be such that the external surface of the guide member can 
be stepped and the adjacent internal surface of the housing can be 
roughened or vice versa. 
The annular portion of the channel preferably diverges in the direction of 
fluid flow from the passage toward the outlet. The guide member and/or the 
housing can be made of a suitable plastic material. Furthermore, the guide 
member can be mounted in or on the housing for movement substantially 
axially of the flow restrictor to thereby vary the rate of fluid flow in 
the channel. In addition, the flow regulator can comprise means for 
releasably holding the guide member in a selected position with reference 
to the housing. Such holding means can include mating internal threads in 
the housing and complementary external threads on the guide member. 
The housing is or can be provided with an internal surface (such as a 
cylindrical internal surface) which spacedly surrounds the flow restrictor 
and is disposed between the shoulder and the inlet. Such housing can be 
further provided with at least one fluid admitting port which has a 
discharge end in the internal surface. For example, the housing can be 
provided with two ports which are disposed substantially diametrically 
opposite each other with reference to the axis of the internal surface. 
The discharge end of each port is or can be adjacent the internal shoulder 
of the housing, and each port can extend substantially radially of the 
flow restrictor. Alternatively, at least one of the ports (or the single 
port) can make an oblique angle with the axis of the flow restrictor. 
Another feature of the invention resides in the provision of a fluid flow 
regulator which comprises a hollow housing defining a channel with a 
fluid-admitting inlet and a fluid-discharging outlet, and a guide member 
which is at least partly disposed in and defines with the housing an 
annular portion of the channel. The guide member includes a flange which 
is disposed at the outlet, and the flange has a plurality of openings 
through which the fluid flows from the annular portion of the channel. The 
guide member can be provided with the aforementioned stud which extends 
into the channel between the annular portion and the inlet. The flange of 
the guide member can be provided with an annulus of arcuate openings in 
the form of closed slots. 
The novel features which are considered as characteristic of the invention 
are set forth in particular in the appended claims. The improved fluid 
flow regulator itself, however, both as to its construction and its mode 
of operation, together with additional features and advantages thereof, 
will be best understood upon perusal of the following detailed description 
of certain presently preferred specific embodiments with reference to the 
accompanying drawing.

DESCRIPTION OF PREFERRED EMBODIMENTS 
FIG. 1 shows a fluid flow regulator 1 which embodies one form of the 
present invention. This flow regulator has a housing 3 which is made of a 
suitable plastic material and is installed in the casing of an adapter 2. 
The housing 3 defines a channel with an inlet at the upper end (as seen in 
FIG. 1) and an outlet at the lower end. Furthermore, the housing 3 is 
formed with an annular internal shoulder 7 which is spaced apart from the 
inlet and outlet of the channel and is adjacent a cylindrical internal 
surface 4 extending from the shoulder 7 toward and normally all the way to 
the inlet. The flow regulator 1 further comprises an elastically 
deformable annular flow restrictor 5 having a surface 5a (FIG. 3) which 
abuts the shoulder 7, and a set of axially parallel apertures 8 (FIGS. 3 
and 4) which are provided in a ring-shaped radially outermost portion 5b. 
Still further, the flow regulator 1 comprises a hollow frustoconical guide 
member 6 (see particularly FIGS. 8 and 9) which is spacedly surrounded by 
the housing 3 between the shoulder 7 and the outlet and cooperates with 
the housing to define an annular portion of the aforementioned channel. 
The flow restrictor 5 is deformable by the conveyed fluid (e.g., water) 
and is movable radially of the socket which is bounded by the internal 
surface 4 of the housing in order to change the cross-sectional outline of 
an annular passage 11 between the frustoconical internal surface 5c of the 
flow restrictor and the cylindrical or substantially cylindrical external 
surface of a relatively short; stud 10 forming an integral part of or 
being rigidly connected with the smaller-diameter end of the substantially 
frustoconical guide member 6. 
The purpose of the flow restrictor 5 is to ensure that the quantity of 
conveyed fluid per unit of time is at least substantially constant 
irrespective of eventual variations of fluid pressure in the conduit which 
supplies fluid to the inlet of the channel in the housing 3, i.e., to the 
upper end of the annular passage 11 between the conical internal surface 
5c of the flow restrictor 3 and the peripheral or external surface of the 
stud 10. The conical surface 5c tapers in a direction from the inlet 
toward the annular portion of the channel between the conical external 
surface of the guide member 6 and the adjacent conical internal surface of 
the housing 3 between the shoulder 7 and the outlet. The flow restrictor 5 
is capable of performing the aforementioned quantity-regulating function 
because it is elastically deformable and because it is also movable 
radially of the stud 10 by sliding along the internal shoulder 7 of the 
housing 3. The extent of deformation of the flow restrictor 5 is a 
function of the pressure differential which develops while the fluid flows 
from the inlet to the outlet of the channel in the housing 3. As already 
mentioned above, such channel includes the passage 11 between the stud 10 
and the conical internal surface 5c of the flow restrictor 3, and an 
annular portion which extends from the shoulder 7 toward the outlet and 
surrounds the conical external surface of the guide member 6. The surface 
5a of the flow restrictor 5 is or can be in sealing engagement with the 
shoulder 7, and the latter is designed to permit radial movements of the 
flow restrictor in order to vary the cross-sectional area of the annular 
passage 11 which is surrounded by the conical internal surface 5c. 
FIGS. 3 and 4 show a first embodiment of the flow restrictor 3 wherein the 
ring-shaped portion 5b is provided with four equidistant apertures 8 in 
the form of slots 9 each of which is parallel with the axis of the flow 
restrictor and extends all the way from the upper end face 5d to the 
surface 5a. The slots 9 extend radially inwardly from the peripheral 
surface 5e of the ring-shaped portion 5b, and that end of each slot 9 
which is provided in the surface 5a is or can be bounded by a relatively 
sharp edge, as at 5f. 
When the pressure of fluid which enters the inlet of the channel in the 
housing 3 rises, the flow restrictor 5 undergoes elastic deformation and 
reduces the cross-sectional area of the annular passage 11 between the 
conical internal surface 5c and the external surface of the stud 10. 
Deformation of the conical surface 5c is indicated in FIG. 2 by dotted 
lines, as at 5c'. The deformation of the flow restrictor 5 (such 
deformation is exaggerated in FIG. 2 for the sake of clarity) is normally 
more pronounced in the region adjacent the shoulder 7 of the housing 3. 
Such deformation is attributable to dynamic pressure or velocity head of 
the fluid in the space between the peripheral surface 5e of the 
ring-shaped portion 5b and the internal surface 4 of the housing 3. At 
least some deformation of the flow restrictor 5 would take place in the 
absence of any apertures in the ring-shaped portion 5b. However, it has 
been found that the apertures 8 (i.e., the slots 9 in the ring-shaped 
portion 5b) ensure practically hindrance-free penetration of fluid all the 
way to the shoulder 7. Fluid which has penetrated into the slots 9 acts 
upon the adjacent weakened (thinner) web-like portions 5g of the flow 
restrictor 5 and causes a pronounced radially inward deformation of such 
portions 5g to thus constrict the path for the flow of fluid from the 
inlet toward the annular portion of the channel between the guide member 6 
and the surrounding portion of the housing 3. 
The number of apertures 8 can be varied within a wide range (e.g., between 
two and fifteen), depending upon the selected operating pressure of 
conveyed fluid. The elasticity of the flow restrictor 5 increases if the 
number of apertures 8 is increased; this is particularly desirable and 
advantageous if the pressure of conveyed fluid is relatively low because 
even such fluid is capable of bringing about pronounced changes in the 
extent of deformation of the flow restrictor. In other words, if the flow 
restrictor 5 is readily deformable (as a result of appropriate selection 
of its material and/or as a result of selection of a large number of 
apertures), its sensitivity to changes of fluid pressure is increased to 
thus ensure that the flow restrictor can react to relatively minor changes 
of fluid pressure and can properly regulate the quantity of a fluid which 
is maintained at a relatively low or even very low pressure. 
The cross-sectional area of the passage 11 can be selected in such a way 
that this passage is not readily clogged by impurities which are entrained 
by the fluid on its way from the inlet toward the outlet of the channel in 
the housing 3. Furthermore, the surfaces bounding the passage 11 are not 
likely to retain even relatively large particles of solid matter because 
the flow restrictor 5 is slidable along the shoulder 7 and can move 
radially of the internal surface 4 (when necessary) in order to widen a 
certain portion of the passage 11. Moreover, as the width of the passage 
11 varies in response to changes of fluid pressure, the surface 5c of the 
flow restrictor 5 acts not unlike a bellows or a membrane and pumps any 
solid particles out of the passage so that the thus dislodged particles 
advance into the annular portion of the channel around the guide member 6. 
One presently preferred material of the flow restrictor 5 is silicone 
rubber. Such material is compatible with foodstuffs (i.e., it does not 
adversely affect the appearance, taste, quality and/or other desirable 
characteristics of foodstuffs). Moreover, silicone rubber exhibits a 
highly pronounced rebound resiliency which is desirable and advantageous 
because this characteristic of the flow restrictor ensures that the latter 
reassumes its undeformed state in response to a reduction of fluid 
pressure within the conical surface 5c and around the peripheral surface 
5e. Still further, silicone rubber can be shaped with a high degree of 
precision with tolerances as small as one or more hundredths of one 
millimeter. 
The large-diameter end or base of the frustoconical guide member 6 is 
formed with a radially outwardly extending circumferentially complete 
projection 12 (hereinafter called flange) which has a set of arcuate 
slot-shaped openings 13 (see FIG. 9). The illustrated openings 13 form an 
annulus having its center on the common axis of the guide member 6 and its 
stud 10. FIG. 9 shows six equidistant openings 13 of identical size and 
shape. As can be seen in FIG. 1, the openings 13 can be disposed in the 
region (actually downstream) of the outlet of the channel in the housing 
3, and their combined cross-sectional area is or can be larger than the 
cross-sectional area of the adjacent end of annular portion of the channel 
between the base of the guide member 6 and the housing 3. Thus, the flange 
12 does not oppose the rate of fluid flow from the housing but actually 
permits expansion at the outlet to thus ensure a more predictable 
regulation of fluid flow from the flow regulator 1. Moreover, the 
provision of a flange 12 with a relatively large number of relatively 
large openings 13 reduces the likelihood of clogging of the channel at of 
its outlet by solid particles which might be entrained by conveyed fluid 
(such as water). Those ends of the openings 13 which are provided in the 
bottom surface 12a of the flange 12 are preferably bounded by sharp edges 
14 (FIG. 8). This not only promotes a breaking up of jets of fluid which 
pass through the openings 13 but also reduces the noise of the outflowing 
fluid medium. 
The stippling of the conical external surface of the guide member 6 is 
intended to indicate that such surface is roughened. The same applies for 
the adjacent internal surface of the housing 1 (see, for example, FIG. 1). 
Roughening of the external surface of the guide member 6 and/or of the 
adjacent internal surface of the housing 3 also contributes to a reduction 
of noise and enhances adhesion of the conveyed fluid to such surfaces. 
FIG. 1 further shows that the axial length of the stud 10 at the 
smaller-diameter end of the guide member 6 is less than the axial length 
of the conical internal surface 5c of the flow restrictor 5. In other 
words, the preferably rounded head of the stud 10 need not project beyond 
the outer end face 5d of the flow restrictor 5. Since the conical internal 
surface 5c tapers in a direction toward the shoulder 7 and toward the 
smaller-diameter end of the conical guide member 6, the cross-sectional 
area of the passage 11 decreases in the direction of fluid flow with 
attendant rise in velocity and drop in pressure of conveyed fluid. 
Therefore, the fluid in the narrowest portion of the passage 11 in the 
region of the shoulder 7 offers a relatively small resistance to radial 
shifting of the flow restrictor 5 along the shoulder 7. 
That portion of the housing 3 which surrounds the internal surface 4 is or 
can be provided with one or more bypass ports 15 (FIG. 1 shows a single 
port 15 because the other port or ports are concealed by the flow 
restrictor 5 and/or adapter casing 2). For example, the housing 3 can be 
provided with two ports 15 which are located diametrically opposite each 
other with reference to the axis of the internal surface 4. The discharge 
ends of the ports 15 are immediately or closely adjacent the shoulder 7, 
and each such port can extend substantially radially of the flow 
restrictor 5. However (and as actually shown in FIG. 1), it is also 
possible to select the orientation of one or more ports 15 in such a way 
that their axes make oblique angles with the axis of the cylindrical 
internal surface 4. Fluid which enters the housing 3 by way of one or more 
ports 15 also contributes to radial shifting of the flow restrictor 3 
and/or to more reliable deformation or termination or reduction of 
deformation, depending upon whether the pressure of admitted fluid rises 
or drops. It has been found that the ports 15 are very effective if the 
inclination of their axes with reference to the plane of the shoulder 7 
does not exceed 50.degree. and is preferably in the range of 15.degree. . 
The number of ports 15 can match, exceed or be less than the number of 
apertures 8 in the ring-shaped portion 5b of the flow restrictor 5. The 
arrangement can be such that each port 15 discharges fluid into one of the 
apertures 8 to thus further promote deformation of the web-shaped weakened 
portions 5g in response to increasing pressure of fluid which is admitted 
into the space around the ring-shaped portion 5b by way of the inlet 
and/or by way of one or more ports 15. 
The adapter 2 of FIG. 1 can be installed in a fitting or valve. The outlet 
of the channel in the housing 3 can discharge fluid into a stream 
regulator. For example, the preferably externally threaded adapter 2 can 
be screwed into the housing of a stream regulator. FIG. 2 shows a 
modification wherein a somewhat different housing 3 of the flow regulator 
1 is installed in a mouthpiece 16 which further contains a stream 
regulator 17 adjacent the outlet of the channel in the housing 3. 
FIG. 5 shows a flow restrictor 5 wherein the ring-shaped portion 5b is 
formed with ten equidistant apertures 8 each of which is a slot 9 having 
an open side in the peripheral surface of the ring-shaped portion 5d. 
FIG. 6 shows a portion of a further flow restrictor 5 wherein the apertures 
8 are holes each of which has a circular or oval (nearly circular) 
cross-sectional outline. The holes or apertures 8 are located radially 
inwardly of the peripheral surface of the ring-shaped portion 5b. 
FIG. 7 shows a portion of a further flow restrictor 5 wherein the 
ring-shaped portion 5b has an annulus of equidistant apertures 8 each of 
which is a hole having a polygonal (e.g., square or rectangular) 
cross-sectional outline. Flow restrictors with apertures having 
cross-sectional outlines other than those shown in FIGS. 4 to 7 can be 
used with equal or similar advantage. As mentioned above, the number, 
distribution, configuration and dimensions of the apertures 8 will depend 
on the required sensitivity of the flow restrictor and upon the expected 
range of pressures of conveyed fluid. 
Since the flow restrictor 5 of the improved flow regulator is or can be 
readily deformable (the deformability is much more pronounced than that of 
a flow restrictor having a constant wall thickness from end to end and 
being devoid of apertures corresponding to the apertures 8 of the improved 
flow restrictor), its dimensions can be reduced (together with the 
dimensions of the entire flow regulator) without affecting the desirable 
properties of the flow regulator. 
The design of FIGS. 3-5 (with apertures 8 in the form of radially extending 
open slots 9) is preferred at this time because the flow restrictor 5 can 
be mass-produced at a low cost and because the open slots 9 greatly 
enhance the deformability of the flow restrictor. A relatively large 
number of apertures 8 is desirable on the ground that this greatly 
enhances the deformability of the flow restrictor 5 as well as the 
uniformity of deformation, i.e., that portion of a strongly deformed flow 
restrictor which abuts the shoulder 7 will closely resemble a ring so that 
the rate of fluid flow in the adjacent portion of the passage 11 will be 
more uniform than if the flow restrictor were provided with a relatively 
small number of apertures. 
FIG. 10 shows a modified fluid flow regulator 100 having a modified housing 
3 which is installed in an externally threaded and knurled adapter casing 
2. The main difference between the flow regulator 100 and the flow 
regulator 1 of FIG. 1 is that the housing 3 of the flow regulator 100 has 
a stepped internal surface 18 which surrounds the roughened conical 
external surface of the guide member 6 and defines with the latter a 
conically diverging annular portion 21 of the channel between the inlet 
and outlet of the housing 3. The configuration of the upper portion of the 
housing 3 (as seen in FIG. 10), of the guide member 6 and its stud 10, and 
of the flow restrictor 5 is or can be the same as described with reference 
to the flow regulator 1. The purpose of the roughened conical external 
surface of the guide member 6 is to reduce noise, or to prevent the 
generation of excessive noise, when a fluid (e.g., water) is caused to 
flow into the passage 11 and thence into the annular portion 21 of the 
channel in the housing 3. 
The stepped internal surface 18 of the housing 3 in the region around the 
annular channel portion 21 is composed of relatively short cylindrical 
sections 20 and annular sections 19 which alternate with the cylindrical 
sections 20 and are disposed in planes extending transversely of the 
direction of fluid flow in the annular channel portion 21. 
FIGS. 10 and 11 show that the axial length of neighboring cylindrical 
sections 20 increases in the direction of fluid flow toward the flange 12 
of the guide member 6. Thus, the shortest cylindrical section 20 is 
adjacent the shoulder 7 and the longest cylindrical section 20 is adjacent 
the flange 12. Such dimensioning of the cylindrical sections 20 is 
preferred at this time because it entails a reduction of the speed of 
fluid in the channel portion 21 with attendant reduction of noise when the 
flow regulator 100 is in use. Thus, the cross-sectional area of the 
channel portion 21 increases in a direction from the shoulder 7 toward the 
flange 12 proportionally or substantially proportionally with a reduction 
of the speed of conveyed fluid. Therefore, the speed of fluid which leaves 
the flow regulator 100 via openings in the flange 12 is relatively low. 
FIGS. 10 and 11 show that the annular edges between the sections 19 and 20 
of the stepped internal surface 18 of the housing 3 are relatively sharp. 
Such sharp edges break up the flow of and thus decelerate the fluid with 
attendant reduction of noise. However, it is equally within the purview of 
the invention to provide the internal surface 18 with rounded edges 
between the cylindrical sections 20 and the adjacent annular sections 19. 
FIG. 11 further clearly shows the socket which is bounded by the 
cylindrical internal surface 4 and the annular shoulder 7 of the housing 
3. The shoulder 7 cooperates with the ring-shaped portion 5b of the flow 
restrictor 5 to prevent the flow of fluid directly from the apertures 8 
into the channel portion 21. In addition, the shoulder 7 provides a seat 
for the surface 5a and enables the flow restrictor 5 to move radially of 
the stud 10 and of the cylindrical internal surface 4. 
FIG. 13 shows a flow regulator 110 which is identical with the flow 
regulator 100 of FIG. 10 except that the conical external surface 18' of 
the guide member 6 is also stepped. The height of cylindrical sections 20 
of both stepped surfaces 18 and 18' increases in a direction from the 
passage 11 toward the flange 12. In addition, the steps of the surface 18 
are staggered with reference to the steps of the surface 18', i.e., the 
annular sections 19 of the surface 18 and the annular sections 19 of the 
surface 18' are disposed at different levels. 
FIG. 14 shows that the distribution and configuration of openings 13 in the 
flange 12 of the guide member 6 which is used in the flow regulator 110 of 
FIG. 13 is the same as that of openings 13 in the flange 12 of the flow 
regulator which is shown in FIG. 9. 
The housing 3 and/or the guide member 6 (with the stud 10) can be 
mass-produced from a suitable plastic material. 
FIG. 16 shows a flow regulator 1' wherein the guide member 6 and its stud 
10 are movable in and counter to the direction of arrow Pf1. To this end, 
the flange 12 of the guide member 6 has external threads 22 mating with 
complementary internal threads 23 of the adjacent portion of the housing 
3. These threads constitute a means for holding the guide member 6 in a 
selected axial position in which the guide member ensures that the fluid 
can flow through the housing 3 at a desired rate. The bottom surface 12a 
of the flange 12 is formed with a centrally located polygonal socket 24 to 
receive the working end of a suitable tool which is used to change the 
axial position of the guide member 6 in or counter to the direction of 
arrow Pf1. The socket 24 is accessible at the outlet end of the housing 3. 
The guide member 6 can be detached from the housing 3 of FIG. 16 for use 
in another housing. Thus, any one of a single series of guide members can 
be used in any one of a variety of housings (e.g., in housings with or 
without stepped internal surfaces 18). This contributes to lower cost of 
the improved flow regulator and renders it possible to reduce the number 
of spare parts which must be held in storage in an establishment which 
distributes, assembles, replaces and/or repairs flow regulators embodying 
the present invention. 
The provision of steps in the internal surface 18 of the housing 3 and/or 
in the external surface 18' of the guide member 6 constitutes a feature 
which is novel per se. It has been found that such stepped surface or 
surfaces contribute to pronounced deceleration of the fluid in the region 
of the outlet of the housing 3 and thereby contribute to a pronounced 
reduction of noise. Experiments indicate that, when the fluid is conveyed 
at a rate of approximately 12 liters per minute, the improved flow 
regulator produces little noise, especially if at least one of the 
surfaces 18, 18' is a stepped surface. The sections 19, 20 of the stepped 
surfaces can be formed at a low cost in readily available machines. The 
provision of relatively sharp annular edges between the neighboring 
sections 19 and 20 is particularly important on the surface 18' of the 
guide member 6 but such sharp edges are also preferred on the conical 
internal surface 18 of the housing 3. As explained above, these annular 
sections and the sharp edges reduce the speed of the conveyed fluid and 
thus contribute to a reduction of noise. 
The feature that the axial length of the sections 20 on the stepped surface 
18 and/or 18' increases in the direction of fluid flow in the annular 
portion 21 of the channel also enhances the desirable characteristics of 
the flow regulator and of the conveyed fluid. Thus, the volume of the 
annular portion 21 increases in the direction of fluid flow which, in 
turn, reduces noise. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic and specific aspects of our contribution to 
the art and, therefore, such adaptations should and are intended to be 
comprehended within the meaning and range of equivalence of the appended 
claims.