AU647512B2

AU647512B2 - A flow governor

Info

Publication number: AU647512B2
Application number: AU82661/91A
Authority: AU
Inventors: Heinz Nolte
Original assignee: Dieter Wildfang GmbH
Current assignee: Neoperl GmbH
Priority date: 1990-12-21
Filing date: 1991-08-23
Publication date: 1994-03-24
Anticipated expiration: 2011-08-23
Also published as: JPH05189052A; KR920013066A; KR960003570B1; ATE133801T1; EP0492111A2; DE4041116A1; EP0492111A3; AU8266191A; EP0492111B1; DE59107347D1

Abstract

A flow controller (1) possesses, inside a housing (2), a regulating core (3) provided on the outside with control grooves (9), around which core is arranged, at a distance, an elastomeric control element (4) designed as an annular body. This control element (4) is supported in the flow direction on an annular shoulder (5). The control element (4) contracts approximately radially inwards as a function of the pressure prevailing on the inflow side and on the outflow side or of the pressure difference resulting therefrom, and thus influences the passage cross-section bounded by the inside of the control element (4). The control element (4) possesses, in the passage gap (11), a comparatively long annular flat face (6) which is adjoined by a conical inlet portion (7) in the inflow direction. The control element (4) protrudes inwards with its radially inner bearing face beyond the annular-shoulder inner edge (8) facing it. <IMAGE>

Description

AUSTRALIA

Patents Act D 4 z Ot COMPLETE SPECIFICATIO~'

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: *@ee9@ S S

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S *5 Name of Applicant: Dieter Wildfang GmnbH Actual Inventor (s) Heinz Nolte Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA .*Sinvention Title: A FLOW GOVERNOR our Ref 225964 POF Code: 1635/148321 .The following statement is a full description of this invention, includinrI *the best method of performing it kno-An to applicant(s): 6006

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Dieter Wildfang GmbH Klosterrunsstr. 11 D-7840 Mllheim A Flow Governor The invention relates to a flow governor having an externally profiled regulating core arranged within a housing, as well as an elastomeric control element which is arranged ringlike around the regulating core and is supported in the direction of flow on an annular shoulder.

German laid open print No. 20 60 751 has already disclosed a flow governor of the kind mentioned at the outset.

In this governor, the flow rate is heavily dependent on dimensional tolerances occuring in the piece parts, particularly in the regulating core and also in the control element. Therefore an adjusting method (German Patent Specification No. 33 02 759) for the injection mould of the profiled regulating core is envisaged, with which adjustment can be made to the desired value of the respective flow rate. By this means, it is possible particularly for varying material properties and dimensional tolerances of the control element to be compensated.

This adjusting method calls for considerable experience and sensitivity and can be conducted only by experts, the mould being ground off at specific locations by means of power driven flexible shaft and miniature pencil grinders in accordance with empirical values and prescribed rules.

Production and the adjusting method are altogether very complex for this governor and such elaboracy is not viable for series production with large piece numbers.

A factor further aggravating this situation is that one specific embodiment of the governor is intended for only one certain flow class, for nominal flow rates in the range of 0.25 litres/min and 50 litres/min, a whole series of different regulating cores and also different control elements having to be used. Accordingly, also a correspondingly large number of sets of moulds is necessary for production.

The object underlying the present invention is to produce an improved fluid flow regulator.

To accomplish this object, according to one aspect of this invention there is provided a fluid flow regulator including a hollow housing having d fluid-admitting inlet, a fluid-discharging outlet and an annular internal shoulder facing said inlet; a guide member in said housing; and an elastically deformable annular flow restrictor disposed in said housing, abutting said shoulder and defining with said guide member a substantially annular clearance for the flow of a fluid from said inlet to said outlet, said flow restrictor having an internal surface surrounding said clearance and including a substantially cylindrical first section and a substantially conical second section between said first section and said inlet, said second section diverging in a direction from said first section toward said inlet, said shoulder having a first inner diameter, said flow restrictor having a second inner diameter at said shoulder, said second inner diameter being smaller than said first inner diameter in an undeformed condition of "30 said flow restrictor.

According to another aspect of this invention there is provided a fluid flow regulator including a hollow housing having a fluid-admitting inlet, a fluid-discharging outlet and an annular internal shoulder facing said inlet; a guide member in said housing; and an elastically deformable annular flow restrictor disposed in said housing, abutting said shoulder and defining with said guide member a substantially annular clearance for g the flow of a fluid from said inlet to said outlet, said 2 flow restrictor having an internal surface surrounding said clearance and including a substantially cylindrical first section and a substantially conical second section between said first section and said inlet, said second section diverging in a direction from said first section toward said inlet, said shoulder having a first inner diameter, said flow restrictor having a second inner diameter at said shoulder, said second inner diameter being smaller than said first inner dj meter in an undeformed condition of said flow restrictor, said guide member having a peripheral surface surrounded by said clearance and having a plurality of passages extending in a direction from said inlet toward said outlet and communicating with said clearance.

Practical tests have shown that the governor is highly insensitive to dimensional tolerances of its piece parts, permitting observance of the tolerance limits prescribed in relation to the 0 0 2a- -3specified nominal value of flow, even in the case of series production with large piece numbers and possibly different batches of component parts. Despite this insensitivity to dimensional tolerances, this governor displays particularly good regulating action in a large pressure range, the design and position of the annular shoulder enabling deformation of the control element in response even to slight pressure differences.

It is also particularly advantageous here that one needs a comparatively small number of variants which, however, in- .corporate the same basic principle. In particular, the outer geometry of the control element may be the same for all embodi- S. ments and the adaptation to different pressure ranges is attaina..

*ed in the control element solely by different material properties.

Consequently, one single mould for the control element can be a. •used for all variants of the governor, this signifying a substantial reduction in expenditure.

~tb is preberre S" teMpaed that distributed on the outer circumference of the regulating core there are control grooves provided which are oriented in the direction of flow, the section of passage thereof and/or cross-sectional shape thereof being adapted to the designated flow rate and/or regulating action of the cons trol element.

Thereby a possibility for adaptation to different operating con- S* ditions is also constituted in the regulating core. This adaptability consists in a directive which then fits the designated operating range without any adapting work being necessary after manufacture. It has proved that with only three different housing configurations incorporating a different regulating core in each case and control elements adapted merely in respect of material A properties, the entire designated range of flow classes can be covered.

/4 praepre.ck cA\ \a.

It isyadn-tagzous if the control grooves provided in the regulating core have a larger section c passage in the intake area on the inflow side than in the area of the gap for passage externally defined by the face of the annular body, in the latter area the gap composing a restrictcr.

In the area of the control grooves in conjunction with the 'It s prr errCi t O.L conical intake portion of the control element,Aa flow guide narrowing conically on either side is thereby formed promoting the control element being drawn approximately radially inwardly •into the zones of the control grooves when it is subjected to the action of commensurate differential pressure.

no Pre.eo-'cr c\a control grooves pe~sably converge on the inflow side and S- there have knife-shaped boundaries, the faces of the regulating core which are situated between the intake orifices of the grooves and point approximately in the direction of inflow, preferably taking the form of roof slopes slanting radially outwardly. This produces a flow-enhancing, largely irrotational 0: guidance and feed of the flow into the narrowed annular gap area. Accordingly, there is little noise produced and also slight resistance to flow in the intake area.

If a radially enlarged expansion space is provided after the annular shoulder in the direction of outflow, this also contributes to low noise. Steadying of the flow and noise reduction takes place in this area.

he 4 regulating core is suitably connected to the outer housing via webs, such connection being established after and preferably in spaced relationship to the control element in the direction of outflow. Hence in the inflow area and also in the regulating portion proper, there are no parts projecting into and swirling the flow in an unwanted manner.

For larger flow rates, at least one channel, preferably a central channel,4i provided in the regulating core.

This channel forms an unregulated by-pass. Therefore the control element together with the regulating core can be devised the same way from the basic concept as for smaller flow rates, because only a part of the total flow passes through in the regulated gap. Therefore this contributes to at least the control element remaining unchanged for larger flow rates.

*t \s o\So jreerr-A that the annular control element has within its area bearing on the annular shoulder recesses oriented approximately in the direction of flow, in the operating position these forming retaining openingcs.

Through these recesses, the control element presents increased flexibility and elasticity permitting deformations regulating the flow to the designated desired value to occur even at lower pressures. Through the increased flexibility and increased restoring capacity (rebound resilience), the movement ot stroke of the control element during operation is also considerably larger, at fluctuating or constant flow pressures, so that the annulus between the control element and the regulating core can be made larger. This in turn leads to the governor being less liable to becoming dirty or clogged.

0 cx\So pife_ e.rred\ Ae ~F -C n. na--deelue, It iS~Poe)temat that the number of recesses in the control element and the number of control grooves in the regulating core are unequal, and that particularly one number is preferably even and the other eaen.

This prevents that in a certain positional relationship of regulating core and control element,unwanted "strangulation" of the passage occurs at high pressures.

/6 A preferred embodiment contemplates that in the regulating core provision is made for a small nurber of control grooves, preferably three, and in that case the control element may have four or more recesses. A small number of control grooves can be produced very uniformly as regards their distribution at the circumference and as regards the same shapes and sizes.

In addition, this has a favourable effect on the regulating action.

ET \s pre.^,-re.Ac that the inner edge belonging to the annular shoulder and facing S. the control element is bevelled, particularlv chamfered and/or rounded. When subjected to the action of differential pressure, o the control element projecting slightly over this inner edge of the annular shoulder can thereby be deformed over this inner edge, whereby a comparatively large radial constriction can be attained in this area even under slight pressurization. This promotes a steep ascent of the characteristic curve in the lower pressure range.

C**

Additional .fvei~hege of the invention are recited in the 4u-ther d* The invention with its leading features is described more closely below with reference to the drawings, in which Fig. 1 is a longitudinal sectional view of a flow governor, Fig. 2 is a top view of the flow governor shown in Fig. 1 on the inflow side thereof, Fig. 3 is a top view of the flow governor according to Fig. 2, but here with the control element deformed, /7 Fig. 4 is a side view of a flow governor, half in section, with the inner edge of the annular shoulder being rounded, Fig. 5 is a view approximating that of Fig. 4, but here with the inner edge of the annular shoulder being chamfered and the control element being deformed, Fig. 6 is a longitudinal sectional view of a flow governor with a channel situated in the regulating core thereof, Fig. 7 is a side view, half in section, of a modified flow

S

governor and Fig. 8 is the flow governor shown in Fig. 7 in a top view cn the inflow side.

A flow governor 1, shown by way of example in Figs. 1 and 2, can be used particularly in flow heaters, in conjunction with solenoid valves, in sprinkler systems, filling systems and the like. It has the task of keeping a flow rate within a given flow class constant, while observing certain tolerance limits, largely independently of supply pressure.

The flow governor 1 has within a housing 2 a regulating core 3, around which an elastic control element 4 consisting of an elastomeric material is arranged.

On the outflow side, the control element 4 bears on an annular shoulder 5 of the housing 2. The direction of inflow is marked by arrow Pfl in Figure 1.

The control element 4 takes the form of an annular body and internally, confronting the regulating core 3, has an annular face 6 running approximately axially parallel adjoined on the inflow /8 side by a conical intake portion 7. The inside diameter d of the undeformed control element 4 (Figs. 1 and 2) is smaller than the diameter D of passage in the region of the annular shoulder 5, so that the control element 4 projects radially inwardly over the inner edge 8 of the annular shoulder.

The regulating core has in the way of external profiling control grooves 9 oriented in the direction of flow. The section of passage thereof and cross-sectional shape thereof are adapted to the designated flow rate and also to the regulating action of the control element 4.

Depending on the embodiment inter alia of the control grooves 9, the flow governor can be employed for flow rates between 0.5 to 9 litres/min. This range can be enlarged up to about 15 litres/ min flow rate if in the regulating core 3 there is a channel e 10 as an unregulated by-pass, as is shown in Fig. 6.

In the exemplified embodiment according to Figs. 1 to 5, there are provided in the regulating core 3 three control grooves 9 which are distributed at the circumference and have a larger r 'ion of passage in the intake area on the inflow side than in the area of the gap for passage 11 externally defined by the annular face 6. Through this shape of the control grooves 9, they converge on the inflow side as is evident in Fig. 2 and there have knife-shaped boundaries 12. The faces 13 of the regulating core 3 which are beside the control grooves 9 and point approximately in the direction of inflow take the form of roof slopes slanting radially outwardly. Altogether this provides for a flow-enhancing conformation of the regulating core area on the inflow side, preventing unwanted turbulence of the inflowing fluid. This contributes among other things toward favourable regulating characteristics and also to a reduction of noise.

The regulating portion is composed essentially by the gap for passage 11 in the area of the annular face 6. This annular face /9 has a comparatively large axial expanse which, in the exemplified embodiment, reaches approximately to the middle of the overall height of the control element 4. The axial expanse of the annular face 6 may amount to about one third to one half the overall height of the control element 4.

Through this comparatively long regulating portion, one achieves high insensitivity to dimensional tolerances both of the control element 4 and of the regulating core 3 with its control grooves 9.

Such dimensional tolerances are unavoidable in series production with large piece numbers. Nevertheless, however, observance of the tolerance limits prescribed in relation to the respective flow rate must be ensured. This is realizable by virtue of the design of the flow governor 1, with the special configuration of the control element 4 in conjunction with the structural measures in the regulating core 3 and also in the annular shoulder Depending on the pressure conditions prevailing on the inflow side and on the outflow side of the flow governor, the control element 4 undergoes constriction dependent on the differential 9 pressure, as is shown in one operating position in Figure 3.

The higher the pressure difference, the more the control element Swill be constricted and thereby reduce the free section of passage. The configuration of the regulating core 3 with its control grooves 9 and the configuration of the control element 4 are adapted to each other in such a way that in a given 9 9 pressure range, which may be e.g. 0.5 to 12 bar, there is a largely constant, specified flow rate.

The configuration of the flow governor 1 according to Figs. 1 to 5 can be employed for a flow rate of about 3 to 9 litres/min.

Within this range, various flow classes can be realized solely by variation of the material properties of the control element 4. In an advantageous way, therefore, the same injection moulds can be used for the piece parts of the flow governor, but nevertheless flow governors for different flow classes can be produced.

The regulating core 3 preferably has only a few control grooves 9, in the exemplified embodiment three control grooves, which lend themselves to being produced with high precision and uniformity. This is also a factor contributing to permitting the dimensional tolerances to be kept small and hence also to keeping the flow rate in narrow tolerance limits.

4 The control element 4 has within its area bearing on the annular o shoulder 5 recesses 14 which in the exemplified embodiment take the form of grooves open-ended radially outwardly. Since the ends of the recesses 14 are bounded on the outflow side by the annular shoulder 5, the recesses 14 form retaining openings.

With these recesses, influence can be exercised on the elastic flexibility of the control element 4. Given a large number of recesses, one accordingly obtains a particularly large degree of elastic flexibility, as is contemplated especially when using the flow governor at low pressures and also low flow rate. In this way, the attributes of the control element 4 can also be varied by way of simply realizable changes of shape, namely a different number of recesses 14. Mention is made that the inside diameter d of the control element 4 can also be simply e adapted by using different insert rings in the injection mould in this area. Hence the gap for passage 11 can be adapted to the designated flow class. As already mentioned above, there is a small number of control grooves 9 provided in the regulating core 3, while the recesses 14 in the control element 4 are adapted in number and shape to the desired attributes of elastic flexibility displayed by the control element 4. In particular, /11 -11it is contemplated that different numbers of control grooves 9 and iacesses 14 be provided, this particularly avoiding a symmetrical association. In the exemplified embodiment, the control element has four recesses 14 on the side of the outer ee and hence an even number of recesses, whereas an uneven number of control grooves 9 are provided, namely three. This asymmetry avoids that in the event of high pressure differences a "strangulation" ensures in which the section of passage of the flow governor is virtually completely closed. This is prevented by the asymmetric arrangement or association of control grooves 9 and recesses 14.

The cross-sectional shaping of the control grooves 9 can also be adapted to the respective operating range. To av'oid the abovementioned "strangulation" at high pressures, the control grooves S* 9 may also have an undercut cross-sectional shape, virtually S o.

precluding the possibility of the cross section of the control grooves being completely filled by the constricting control element 4. This is also largely attained with angular crosssectional shapes. Apart from the illustrated semicircular crosssectional shape (Fig. 9) or the shape with parallel sides and rounded base Fig. a cross-sectional shape shallower in comparison with Figure 8 may be provided for lower ,ressures, or particularly for higher pressures an angular cross-sectional shape rectangular or square with different groove depth, triangular or undercut, e.g. dovetailed. Alternatively, instead of one single groove, there may be a control groove consisting of several partial grooves side by side.

In the exemplified embodiments according to Figures 1 to 5 and 7 to 8, the regulating core 3 extends in the axial direction to about the level of the inflow side of the control element. Depending on the flow rate, this axial expanse of the regulating core 3 can also be changed. For relatively high rates of flow, a /12 -12regulating core shorter in its axial expanse may be provided, as is shown by way of example in Figure 6.

As is to be seen in Figures 4 to 6, the inner edge 8 belonging to the annular shoulder and facing the control element 4 may be configured in different ways.

Figure 4 shows a rounded inner edge, Figure 5 a chamfered inner edge and Figure 6 a practically sharp-cornered inner edge.

This shaping, combined with the radially inwardly projecting control element 4, allows the regulating action to be steered.

The comparatively large projection accompanied by the rounded or chamfered inner edge 8 enhances sensitive response of the governor even under slight pressure differences. As is indicated in Figure 5, the control element 4 is deformed over the rounded e, or chamfered inner edge 8 towards the outflow side, the extent of this deformation depending on the differential pressure. As the presssure difference increases, the control element 4 is supported to a greater degree at the underside, so that here an adaptation to the changing pressure conditions automatically ensues. The deformation over the inner edge 8 is also simultaneously accompanied by approximately radial constriction and thereby narrowing of the gap for passage 11. A chamfering or rounding of the inner edge 8 of the annular shoulder, particularly together with a comparatively large radial inward projection of the control element 4, is contemplated particularly for small flow rates and also low pressires. Through these measures, one can also attain an oversteering of the governor in the lower pressure range. This is advantageous if, for instance, the fitting itself in which the flow governor 1 is inserted has a flow pressure characteristic curve with a gently ascending flow rate in the low pressure area.

If the flow governor 1 then has in the low .c pressure area a /13 characteristic curve oversteering the desired flok value, then by superimposition a characteristic curve is produced which in the required manner achieves the desired value of tha flow rate even at very low pressures.

This influence on the characteristic curve can be achieved solely by the extent of the projection of the control element 4 over the inner edge 8, as well as combined with the shaping of the inner edg-. The flow governor shown in Figure 6 is contemplated for higher flow rates of e.g. 8 to 15 litres/min. Here it is also to be seen that accordingly the inner edge 8 of the annular shoulder is sharp-cornered and that also the radial projection of the control element 4 over this inner edge is less than in the variants according to Figures 4 and 5. In a ition, the channel 10 arranged centrally in the regulating core 3 is also provided as an unregulated by-pass. The control grooves 9 are here provided in the sleeve-like regulating core 3 externally, running approximately axially parallel. On the inflow side and on the outflow side transition slopes are provided internally, on the inflow side these being brought together to form a knifeshaped and thereby flow-enhancing intake edge The intake portion 7 belonging to the control element 4 and adjoining the annular face 6 on the inflow side forms a flowenhancing inlet to the gap for passage 11. The cone angle may be about 250 to 350, preferably 300.

The central regulating core 3 is connected to the housing 2 via webs 16, such connection being established after and preferably in spaced relationship to the control element 4 in the direction of outflow. Figure 2 indicates that these webs 16 are in each case arranged in the intermediate zones between adjacent control grooves 9 of the regulating core 3. Since they are located after the regulating portion in the direction of outflow, they have no disturbing effect on the regulating action. These webs 16 might be given a flow-enhancing shape on the inflow side, by way of -14example through roof slopes or radii.

Figures 7 and 8 show a flow governor 1 usable for small flow rates, for instance in the range of 0.5 to 3.5 litres/min. In this exemplified embodiment, approximately; axially pmallelatrol grooves 9 are provided in the regulating core 3. This exemplified embodiment also shows after the annular shoulder 5 in the direction of outflow a radially enlarged expansion space 17, through which steadying of the flow and noise reduction can be attained.

Such an expansion space 17 may also be provided in the exemplified embodiments according to Figures 1 to 6.

4 0 All the features set forth in the specification, claims and drawings may be essential to the invention in their own right as well p as in any combined form.

a Patent Claims 0 0 Ge

Claims

1. A fluid flow regulator including a hollow housing having a fluid-admitting inlet, a fluid-discharging outlet and an annular internal shoulder facing said inlet; a guide member in said housing; and an elastically deformable annular flow restrictor disposed in said housing, abutting said shoulder and defining with said guide member a substantially annular clearance for the flow of a fluid from said inlet to said outlet, said flow restrictor having an internal surface surrounding said clearance and including a substantially cylindrical first section and a substantially conical second section between said first section and said inlet, said second section diverging in a direction from said first section toward said inlet, said shoulder having a first inner diameter, said flow restrictor having a second inner diameter at said shoulder, said second inner diameter being smaller than said first inner diameter in an undeformed condition of said flow restrictor.

2. The fluid flow regulator of claim 1, wherein said guide member has a first length, as measured from said inlet toward said outlet, and said first section has a second length which is between substantially one-third and one-half of said first length. 5 3. The fluid flow regulator of claim 2, wherein said second section has a third length which equals or approximates said second length.

4. A fluid flow regulator including a hollow housing having a fluid-admitting inlet, a 30 fluid-discharging outlet and an annular internal shoulder facing said inlet; a guide member in said housing; and an elastically deformable annular flow restrictor disposed in said housing, abutting said shoulder and defining with said guide member a substantially annular clearance for the flow of a fluid from said inlet to said outlet, said flow restrictor having an internal surface surrounding said clearance and including a substantially cylindrical first section and a substantially conical second section 3-9 between said first section and said inlet, said second 15 section diverging in a direction from said first section toward said inlet, said shoulder having a first inner diameter, said flow restrictor having a second inner diameter at said shoulder, said second inner diameter being smaller than said first inner diameter in an undeformed condition of said flow restrictor, said guide member having a peripheral surface surrounded by said clearance and having a plurality of passages extending in a direction from said inlet toward said outlet and communicating with said clearance. The fluid flow regulator of claim 4, wherein said passages define paths for the flow of fluid therein at a preselected rate.

6. The fluid flow regulator of claim 5, wherein said rate is a function of a deformability of said flow restrictor at different pressures of fluid in said clearance.

7. The fluid flow regulator of any one of claims 4 to 6, wherein said passages have a first cross-sectional area at said inlet and a smaller second cross-sectional area at said first section.

8. The fluid flow regulator of any one of claims 9o 9 go o• 9 *9g9 9 9 4 to 7, wherein said passages have intakes which converge toward each other at said inlet and said guide member has 25 pronounced ridges between said intakes.

9. The fluid flow regulator of any one of claims 4 to 8, wherein said guide member has a front side facing said inlet and including facets disposed between said passages and sloping toward said outlet in a direction toward said flow restrictor. The fluid flow regulator of any one of claims 1 to 9, further comprising means for connecting said guide member to said housing.

11. The fluid flow regulator of claim 10, wherein said connecting means includes webs disposed between said shoulder and said outlet.

12. The fluid flow regulator of any one of claims 1 to 11, wherein said guide member defines at least one 39 path for the flow of fluid from said inlet to said outlet 16 0 independently of the flow of fluid through said clearance.

13. The fluid flow regulator of claim 12, wherein said guide member has a substantially centrally located bypass which defines said at least one path.

14. The fluid flow regulator of claim 1, wherein said guide member includes a sleeve having a centrally located hole, a front end facing said inlet, a rear end facing said outlet and a peripheral surface surrounded by said clearance, said peripheral surface having a plurality of substantially axially parallel passages communicating with said clearance and said passages having a depth which decreases in a direction toward at least one of said ends. The fluid flow regulator of claim i, wherein said flow restrictor includes an outer portion which overlies said shoulder and is provided with channels extending toward said shoulder and having fluid-admitting ends facing said inlet.

16. The fluid flow regulator of claim 15, wherein said flow restrictor has a peripheral surface and said channels are provided in said peripheral surface and are substantially parallel to the direction of fluid flow in said clearance from said inlet toward said outlet.

17. The fluid flow regulator of claim 15 or claim 16, wherein said guide member has a peripheral surface and a plurality of passages provided in said peripheral surface and communicating with said clearance, the number of said passages being different from the number of said channels.

18. The fluid flow regulator of claim 17, wherein one of said numbers is an odd number and the other of said numbers is an even number.

19. The fluid flow regulator of claim 17 or claim 18, wherein said passages are substantially equidistant from each other in the circumferential direction of said clearance and the number of said channels exceeds the number of said passages. The fluid flow regulator of claim 19, wherein said peripheral surface has three passages and said flow 39 restrictor has at least four channels. -LI 0< 17

21. The fluid flow regulator of claim 15, wherein said guide member has a peripheral surface and a plurality of passages provided in said peripheral surface and communicating with said clearance, each of said passages having a first cross-sectional outline and each of said channels having a different second cross-sectional outline.

22. The fluid flow regulator of any one of claims 1 to 21, wherein said housing includes a tube haing a centrally located axis and said second section makes with said axis an angle of between substantially 250 and

23. The fluid flow regulator of claim 22, wherein said angle is at least substantially

24. The fluid flow regulator of any one of claims 1 to 23, wherein said housing has a bevelled edge which is bounded by said shoulder. The fluid flow regulator of claim 1, wherein said housing includes a tube having a central axis and said first section has a first length in the axial direction of said tube, said guide member having a second length at least matching said first length. S. 26. The fluid flow regulator of claim 25, wherein said second section has a front end at said inlet and said guide member extends in a direction toward said inlet at least to the front end of said second section. 25 27. The fluid flow regulator of claim 1, wherein said housing has an expansion chamber between said shoulder and said outlet. housing having a fluid-admitting inlet a 0 fluid-discharging outlet and an annular intern* shoulder facing said inlet; a guide member in sa ousing; and an elastically deformable annular fl estrictor disposed in said housing, abutting said ulder and defining with said guide member a subs ially annular clearance for the flow of a fluid said inlet to said outlet, said flow restrictor ving an internal surface surrounding said clea e, said shoulder having a first inner diame said flow restrictor having a second diameter at -18 c;

29. A fluid flow regulator substantially as herein described with respect to any one of the embodiments illustrated in the accompanying drawings. DATED: 20 August 1993 S. C .4 *4 *4 C 54 S SC PHILLEPS ORMONDE FITZPATRICK Attorneys for: DIETER WILDEANG GmbH :3 ~VF 9O 19