GB2185091A

GB2185091A - Valve assembly for a thermostatic valve

Info

Publication number: GB2185091A
Application number: GB08700018A
Authority: GB
Inventors: Volker Spies; Knud Aage Hansen
Original assignee: Danfoss AS
Current assignee: Danfoss AS
Priority date: 1986-01-04
Filing date: 1987-01-02
Publication date: 1987-07-08
Anticipated expiration: 2007-01-02
Also published as: NL188114C; IT1196895B; GB8700018D0; SE8605465L; FR2592700A1; GB2187823B; NL8603244A; DK156096B; SE463275B; CA1280727C; GB2185091B; GB2187823A; DE3600130A1; IT8667992A0; DK156096C; DK621086D0; SE8605465D0; FR2592700B1; DE3600130C2; NL188114B

Abstract

A fitting for a thermostatic valve comprises a housing (1) with a bore (33) which receives a valve insert (11). The latter consists of a shank carrier (12) and a seating carrier (13), adjacent ends thereof being received within a union (4). An outer portion of the shank carrier (12) carries means (36) for securing a thermostat. The shank carrier (12) is secured to the union (4) and the seating carrier (13) comprises retaining means (24,29) within the union (4) for defining its axial position. The axial length of the bore (33) is preferably considerably longer than that of a sealing head (34) on an extension (32) of the seating carrier (13). The seating carrier (13) may be of brass or plastics, and may have a throttling bore. An adaptor may be provided, e.g. to fit on a screwthreaded formation (46) on the shank carrier, for receiving different types of thermostat. <IMAGE>

Description

SPECIFICATION Valve assembly for a thermostatic valve This invention relates two a fitting or valve assembly for a thermostatic valve comprising a housing with a component-receiving union, as an extension thereof a cylindrical bore leading to a connector and, between these, a chamber connected to at least one further connector, and comprising a valve insert which is for securing to the component-receiving union, engages in the component-receiving union with an inner portion, carries at an outer portion a coupling device for securing a thermostat attachment, and is subdivided into a shank carrier and a seating carrier of which a tube extension is provided with a sealing head with a circumferential seal for engaging in the cylindrical bore, particularlyfor plate-radiatorvalves.

Such a fitting is known from DE-AS 2527 132. This describes a thermostatic valve of which the housing is disposed between two plate radiators and ofwhich the horizontally extending component-receiving union terminates within the iimits of the radiators.

The shank carrier carrying the closing member is screwed into the seating carrier. The seating carrier is secured to the component-receiving union by a coupling nut, projects outwardly beyond the end of the plate radiators and at this position has thecoupling device for securing the thermostat attachment.

The coupling nut presses an abutment of the seating carrier againstthe end face ofthe componentreceiving union, a seal being interposed, whereby the axial position of the seating carrier is fixed. The axial length ofthe cylindrical bore only slightly ex ceedsthatofthesealing headofthetubularexten- sion ofthe seating carrier. This takes into account any tolerances occurring during the installation. The use of such a valve insert consisting of a seating carrier and shank carrier has the advantagethatthe housing need only be coarsely machined (screwthread, axial bore) whereas all the components requiring precision machining are combined in the valve insert.Consequently, the valve housing can already be welded to the radiatorduring manufacture whereas the valve insert is built in onlyafterthe radiators have been installed.

It is also already known to insert a shank carrier directly in a component-receiving union of a housing and to apply a coupling device to the housing. However, in this case the valve seat is in the housing so thatfine machining of the housing is indispensable.

It is further known (DE-PS 22 53 462) to separate the seating carrierfrom the shankcarrierforthe purpose of settling the kvvalue, a ring carrying the coupling device engaging a component-receiving union byway of an external screwthread and loading the shank carrier axially, the shank carrier pressing the seating carrier against an abutment face provided in the region of the seat.

In practice, a large number of very different thermostatic valves is employed. For example, they differfromoneanotherwith regard tothe length of the component-receiving union (because the connections to the plate radiators have a different spacing from the end ofthe radiators),with regardtothe thermostat attachment (the coupling devices are not standardized) and soon. Consequently, a particular valve insert is provided for each application and a corresponding multiplicity of constructions must be made and held in stock.

The invention is based on the problem of providing a fitting ofthe aforementioned kind of which the components are veryversatile to result in usage in large numbers and corresponding manufacturing advantages.

This problem is solved according to the invention in that the separating gap between the shank carrier and seating carrier is disposed in the inner portion of the valve insert, that the outer portion carrying the coupling device is formed by the shank carrier, that the shankcarrier is secured to the component- receiving union, thatthe seating carrier has retaining means within the component-receiving union for securing its axial installation position, and that the axial length ofthe cylindrical bore is considerably longerthanthatofthesealing head.

In this construction, one and the same valve insert can be employed for component-receiving unions of different lengths because, for a shorter length, the sealing head simply engages more deeply in the cylindrical bore. The precise length of bore depends on what length variations of the componentreceiving union occur in practice. In any case, a single type of seating carrier can cope with all our a considerable range ofthese length variations.

Sincethecoupljng device is carried bytheshank carrier, it is possible to replace or modifytheshank carrierfor adapting to different thermostat attachments. This can likewisecovera large rangeofvariations in the coupling diameter because the external diameter of the shank carrier can be kept smaller in the coupling zone than if the coupling device were formed on acomponentsurroundingtheshankcar- rier.

If the seating carrier is provided with a fixed throttleforfixing the kVvalue, a series of seating carriers with different kv values can be provided without resulting in an excessively large number of seating carriers to be kept in stock. This is because these seating carriers are independent of the length ofthe component-receiving union and ofthedesired thermostat attachment.

In the simplest case, the shank carrier has an external screw-thread engaging in an internal screwthread ofthe component-receiving union. This permits the use of a comparatively small diameter Beyond this screwthread, the shank carrier may have a section of larger diameterwith a circumferential seal held in a groove. In addition to the sealing function,this can provide a stepforaxiallyfixing the shank carrier.

Itis particularlyfavourableforthe shankcarrierto be provided with a securing device for holding the seating carrier at least temporarily. The shank carrier and seating carrier can therefore already be assembled before building-in and then together inserted in the housing. This facilitates assembly.

The securing device ofthe shank carrier may be an internal screwthread into which an external screwth read of the seating carrier is screwed. This provides a permanentattachmentwhich can also be utilised for fixing the seating carrier axially.

The securing device ofthe shank carrier may, however, also be a circumferential groove in which lugs provided on the seating carrier engage resiliently. To achieve this resilient movability, the elasticity of the material will generally suffice but it may also be obtained by additional axial slots.

It isfavourableforthe securing device of the shank carrier to be disposed on the inside of a ring exten sion which carries the external screwthread for sec- uringtothebuilding-in nipple. This gives an axially short construction.

The retaining device of the seating carrier can be particularly formed by a circumferential flange which co-operates with an end face of the shank carrier. For exa m ple, with a screwthreaded attachment of the seating carrier to the shank carrier, the circumferential flange may define the end position.

In a different embodiment, the circumferential flange can be pressed by the end face of the shank carrier against a step in the building-in nipple. This securely holds the seating carrier axially.

The seating carrier may, as is usual, be of metal. In a particularly preferred embodiment, however,the seating carrier is of plastics. Such plastics components can be very economically but nevertheless precisely manufactured by injection moulding.

There is no danger of over-stressing the plastics material during operation because onlytheforces exerted on the seat by the closing member are transmitted astensileforces.

In particular, the plastics material may be cold flowing and annular beads may project on the end faces ofthe circumferential flange. This results in secure clamping ofthe circumferential flange when the shank carrier is screwed in.

The axial length of the cylindrical bore depends on the length variations of the building-in nipple. In practice, the length is at least 1.8 times but preferably more than twice the axial length of the sealing head.

In particular, the cylindrical bore has a length substantially equal to the height ofthechamber in the housing. The distance of displacement should be equal to at least half the height of the chamber in the housing. The best utilisation of space is obtained if the cylindrical bore has a length substantially equal to the length ofthetube extension.

In a preferred embodiment, the outer portion of the shankcarrier has a securing deviceforapplying an adaptor ring carrying the coupling device. To adapt to a different thermostat attachment, there- fore, it is merely necessaryto apply or replace the adaptor ring. In other respects, the shank carrier may remain unchanged. This provides considerable rationalization advantages.

It is recommended forth adaptor ring securing device to have an external screwthread associated with an annular abutment. By tightening this adaptor ring against the abutment, one obtains a defined position.

The adaptor ring securing device may be provided axially beyond a coupling device that is permanently applied to the shankcarrier. The adaptor ring is therefore required for only some of the applications.

In a preferred embodiment, a coupling device per manentlyapplied to the shank carrier is formed buy a coupling ring which is mounted for rotation but only slight axial displacement on a cylindrical bearing surface of the shank carrier and is provided with a radial lug for engaging in a radial groove attheend ofthe component-receiving union. The rotatable coupling ring may have a smaller radial thickness than a ring screwed thereon. The radial lug will then provide the necessary security againstrotation.

In this case it isfavourableforthp cylindrical bearing surface to have a flat circumferential groove and forthecoupling ring to be deformed into the circumferential groove at isolated points. Such deformation at isolated points for the purpose of axial fixing is simplestto bring about at thinner portions ofthe ring such as those produced at the base of axial grooves.

Desirably, the cylindrical bearing surface has a larger diameter than the external screwthread of the adaptor ring securing device and the end ofthe coupling forms the annular abutment. this permits simple manufacture of the shank carrierwithout having to form the annular abutment on it.

Further, a circumferential groove with a conical side wall can be provided between the adaptor ring securing device and the coupling device perman entlyapplied to the shank carrierso as to axiallyfix the thermostat attachment.

With particular advantage, the componentreceiving union and the end part qfthe housing carrying the cylindrical bore are welded into a central portion ofthe housing bounding the chamber. The component-receiving union and the end part ofthe housing are therefore made separately. This is per missiblewithout any machining being required after welding becausethesealing head balances out most tolerances in the cylindrical bore. Beyond this, it is merely necessary to use a component-receiving union of different length without altering the other valve components for adapting to a particular radiator.

The invention extends to a shank carrier and a seating carrier having the features necessary for using with the previously described fitting. These components can be marketed separately and adapted to a particular application. Nor do the featuresfor adaptation prejudice the use of the shank carrier without a seating carrier, that is in conjunction with a valveseatfixed in the housing. If one adds thins use of the shank carrier, one achieves still larger utilisation numbers.

Valve assemblies constructed in accordance with the invention will now be described, by way of ex ample only, with reference to the accompanying drawings, in which: Figure lisa longitudinal section through a first embodiment; Figure2 is a longitudinal section through a similar embodiment but having a longercomponent receiving union; Figure3 is a section through the region of the seat and tube extension of a seating carrier; Figure4is a longitudinal sectionthrough the outer part ofashankcarrierwith an adaptor ring placed overit; and Figure 5is a plan view corresponding to Figure 4.

The valve assembly illustrated in Figure 1 fora thermostaticvalvecomprisesa housing 1 having a central portion 2, an end portion 3 and a componentreceiving union 4 (that is, a connecting piece into which a part is to be built or inserted). The housing is extended for installation between two adjacent flat radiators, a connector 5 being welded on installation to an aperture in thefrontwall of one ofthe radiators and a connector6 being welded to an aperture in the rearwall ofthe otherone ofthe radiators. A passage 7 in the housing end portion 3 leads to a supply con nector. The union 4 is welded to the central portion 2 along a junction 8 and the end portion 3 is welded to the central portion 2 along a junction 9.A chamber 10 isthus formed in the interior of the housing 1.

Into the housing 1 there is inserted a valve insert 11 consisting primarily of a valve shank carrier 12 and a valve seating carrier 13. The shank carrier 12 carries a closure member 14 by means of a shank 15. The shank 15 is urged towards the open position by a return spring 16 acting against a step 17 on the shank and a seat 18 provided on the shank carrier 12. Asealing insert 19 through which a pin 20 passes is screwed into the free end ofthe shank carrier. By means ofthis pin, the actuating shank of a thermostat attachment (not shown) can act axially on the valve shank 15. The shank carrier 12 has a cylindrical extension 21 provided with an external screwthread 22 for engaging an internal screwthread ofthe union 4 and an internal screwth read 24for cooperating with an external screwthread 25 oftheseating carrier 13.Still further outwardly, there is a section 26 of lar- ger diameter with a circumferential seal 27 held in a groove. This section 26 defines the axial position of the shank carrier 12 by abutmentagainsta step 28 of the union 4.

The seating carrier 13, which is of metal, for ex- ample brass, has a circumferential flange 29 which co-operates with an end face 30 ofthe shank carrier 12 and in this way definesthe axial position ofthe seating carrier 33. Beyond the seat 31, a tubularex- tension 32 extends into a cylindrical bore 33 in the end portion 3 of the housing. The tubular extension 32 is provided with a sealing head 34 having a circumferential seal 35.

As a coupling device 36forsecuring a thermostat attachment, there is provided a coupling ring 37 which has axial grooves 38 on the outer periphery and which, before insertion into the union 4, is rotatable on a cylindrical bearing surface 39 ofthe shank carrier 12. It is prevented from coming off in thatthe material of the coupling ring 37 is deformed into a shallow circumferential groove 41 by means of a spike or the like at several positions 40 indicated by an arrow. The coupling ring is thus retained yet has a slight axial play. The coupling ring also has a radial lug 42 engaging in a radial notch 43 at the end ofthe union 4. In this way, the shank carrier 12 can be screwed into the housing but the rotary position of the coupling ring 37 is neverthelessfixed.Thecoupling ring 37 is preceded by a circumferential groove 44 with an oblique sidewall 45. When athermostat attachment is pushed on to the coupling device 36, a radially positionable element of the thermostat attachment is caused to engage in the circumferential groove 44 and securethe thermostat attachment axially.

This circumferential groove 44 is preceded by an external screw-thread 46 having a slightly smaller diameterthan the bearing surface 39. An adaptor ring can be screwed on to this screw" 4h read as will hereinafter be described in conjunction with Figures 4and5.

The example of Figure 2 consists of much the same components asthat of Figure 1. Accordingly, corresponding parts are indicated by reference numerals increased by 100. The following arethees- sential differences. The union 104 is longerthan in Figure 1. Accordingly, the sealing head 134 is no longer at the lower butatthe upper end ofthe cylindrical bore 133 in the housing end portion 103. The possible displacement is substantially equal to half the height ofthe chamber 10. All told, the cylindrical bore 133 may correspond to the height ofthe chamber 10.

The seating carrier I 1 & nd thus also the seat 131 are of plastics material. The seating carrier 113 is provided at its outer end with axial slots 47 sothat the sections 48 therebetween can be flexed inwardly.

The sections 48 carry projections 124 which can lock in a corresponding circumferential groove 1 25 of the shank carrier 112. This produces an at leasttemporary attachment of the seating carrierto the shank carrier, as is desirable for installation. A circumferential flange 129 has an annular bead 49 so that, when the shank carrier 112 is screwed tight in the building-in nipple 104, this annula.r bead 49 is pressedagainstastep50ofthe housing 101,the plastics being partially deformed by cold flow.

The Figure3 embodiment illustrates a seating carrier213 with seat 231 and closure member214,the difference from the seating carrier of Figures 1 and 2 only being that a throttle bore 51 is provided con centric to the seat for determining the kvalue of the valve. Accordingly, by replacing the seating carrier, onecan selectthe maximumflowaccording tothe data ofthe radiator installation. In the embodiment of Figures 4 and 5, the shank carrier 12 of Figure 1 is merely supplemented by an adaptor ring 52 screwed on to the external screwth read 46. This adaptor ring is screwed on until it strikes the abutment surface 53 formed by the end face ofthe coupling ring 37.The adaptor ring 52 has numerous axial grooves 54atthe periphery that are suited to a thermostat attachment different from that suited to those of the coupling ring 37. The adaptor ring may of course also have a different form, for example be prqvided with an external screw-thread ora much largerdiameter.

The coupling device 36 can for example be used in conjunction with a thermostat attachment of the kind disclosed in DE-PS 3236371. The coupling device with the adaptor ring 52 can be used in conjunction with a thermostat attachment of the kind disclosed in DE-PS 31 12138.

With the aid of a valve assembly as described, a valve housing 101 suitable for the selected radiator can be chosen by the manufacturer. Regardless of this,the mechanic installing the radiatorcan selecta particular make of thermostat attachment as desired bythecustomerwhilstusing muchthesamecom- ponents and he can select a particular kv value ac- cording to the data of the installation. Nevertheless, manipulation is simple because the shank carrier and seating carrier can together be installed and removed.

Thetubularextension32 mayalsohavethesame orsubstantiallythesame external diameterthroughout. In this case, the "sealing head" would merely bethesealing zone around the circumferential seal 35 which should, at most, be threetimes the width of the circumferential groove.

The invention is not restricted to valve assemblies having welded housings but can also be applied to valve assemblies having cast housings. It has part icular advantages with flat (or plate) radiators but may also be employed for other radiators and for other purposes.

Claims

1. Avalve assembly for use in a thermostatic valve,thevalve assembly having a housing with a union, a bore extending from the union toaconnec- tor, and a chamber, between the union and the con nector, connected to at least one further connector, the valve assembly inciuding a valve insert for secur- ingtothe union with a partofthevalve insert being received within the union, the part of the valve insert outside ofthe union being provided with coupling means for securing a thermostat attachment to the valve assembly, wherein the valve insert comprises a valve shank carrier and a yalve seating carrier, adjacent ends of the valve shank carrier and the valve seating carrier are within the union, the coupling means is provided on the valve shank carrier, the valve shank carrier is secured to the union, and retaining means, provided on a part of the valve seating carrier within the union, definethe axial position of the valve seating carrier.

2. Avalve assembly as claimed in claim 1, wherein the bore is cylindrical, the valve seating carrier has a tubular extension provided with circumferential sealing meansforsealingagainstthewallof the bore, and the axial length ofthe bore is long in relation to the axial extent pf the sealing means.

3. Avalve assembly as claimed in claim 1 or claim 2, wherein the valve shank carrier is provided with an external screwthread mating with an internal screw th read ofthe union

4. Avalve assembly as claimed in claim 3, wherein the valve shank carrier is provided with sealing means, of larger diameterthan the external screwthread and having a circumferential seal positioned in a groove, to form a seal with the union at a location axially further out than the mating screwthreads.

5. A valve assembly as claimed in any preceding claim, wherein the valve shank carrier is provided with securing meansforretaining,atleasttem- porarily,thevalveseating carrier.

6. Avalve assembly as claimed in claim 5, wherein the securing means comprises an internal screwthread on the valve shank carrier, and a mating external screwthread is provided on the valve seat ing carrier.

7. Avalve assembly as claimed in claim 5, wherein the securing means comprises a circum ferential groove, and the valve seating carrier is provided with resiliently movable projections to engage the groove of the securing means.

8. Avalve assembly as claimed in any one of claims 5 to 7, wherein the securing means is located on the inside of a tubular extension ofthevalve shank carrier means, and an external screwthread is provided on the outside of the tubular extension for securing the valve shank carrierto the union.

9. A valve assembly as claimed in any preceding claim, wherein the retaining meansofthevalveseat- ing carrier comprise a circumferential flange cooperating with an end face of the valve shank carrier.

10. Avalve assembly as claimed in claim 9, wherein the circumferential flange is arranged to be pressed by the end face of the valve shank carrier against a step provided in the union.

11. Avalve assembly as claimed in anypreceding claim, wherein the the valve seating carrier is made of plastics material.

12. Avalve assembly as claimed in claim 11, wherein the plastics material is a deformable plastics material and at least one annular bead projectsfrom the end face of the circumferential flange.

13. Avalve assembly as claimed in claim 2 or any of claims 3 to 12 when dependentpn claim 2, wherein the length of thecylindridal bore is substantially equal to the height ofthe chamber in the housing.

14. Avalve assembly as claimed in claim 2 or claim 13 or any of claims 3 to 1 when dependent on claim 2, wherein the distance the circumferential sealing means of the tubular extension of the valve seating carrier is displaced in the cylindrical bore in use is at least equal to halfthe height of the chamber in the housing.

15. Avalve assembly as claimed in claim 2 or claim 130rclaim 140ranyofclaims3to 12when dependent on claim 2, wherein the cylindrical bore has a length substantially equal to the length of the tubular extension of the valve seating carrier.

16. Avalve assembly as claimed in any preceding claim, wherein the coupling means of the outer part ofthe valve shank carrier comprises a securing means for receiving an adaptor ring for coupling a thermostat attachment.

17. Avalve assembly as claimed in claim 16, wherein the securing means for an adaptor ring comprises an external screwthread and an associated annular abutment.

18. Avalve assembly as claimed in claim l6or claim 17, wherein the coupling means comprises both an adaptor ring securing means and a thermostat attachment coupling, and the adaptor ring secur ing means is provided axially further out than the thermostat attachment coupling.

19. A valve assembly as claimed in any preceding claim, wherein the coupling means comprises a rotatably mounted coupling ring axially retained on thevalveshankcarrier.

20. Avalve assembly as claimed in claim 19, wherein the coupling ring is rotatably mounted on a cylindrical bearing surfaceofthevalveshankcarrier and is provided with a radially-projecting lug engaging in a notch on the end of the union.

21. Avalve assembly as claimed in claim 20, wherein the cylindrical bearing surface is provided with a shallow circumferential groove and the material ofthe coupling ring is deformed at isolated points into the shallow circumferential groove.

22. Avalve assembly as claimed in claim 20 when dependent on claim 17 or claim 21 when dependent on claim 17, wherein the cylindrical bearing surface has a Iargerdiameterthantheexternal screwthread ofthesecuring meansforan adaptor ring, and the end ofthe coupling ringformsthe associated annular abutment.

23. Avalve assembly as claimed in claim 18 or any of claims 19 to 22 when dependent on claim 18, wherein a circumferential groove with a part-conical sidewall is provided, between the securing means for an adaptor ring and the thermostat attachment coupling, for axially retaining a thermostat attachment.

24. Avalve assembly as claimed in any preceding claim, wherein the union and an end portion of the housing with the bore are welded into a central por tionofthehousingwhich bounds the chamber.

25. A valve assembly for use in a thermostatic valve, the valve assembly being substantially as herein described with reference to, and as illustrated by, Figure 1 of the accompanying drawings.

26. Avalve assembly as claimed in claim 25 but modified substantially as herein described with referenceto, and as illustrated by, Figure 2 ofthe ac companying drawings.

27. Avalve assembly as claimed in claim 25 but modified substantially as herein described with referenceto, and as illustrated by, Figure3 oftheac companying drawings.

28. Avalve assembly as claimed in claim 25 but modified substantially as herein described with reference to, and as illustrated by, Figures 4 and 5 of the accompanying drawings.

29. Avalveshankcarrierforusein avalve assembly as claimed in any preceding claim.

30. Avalveseating carrierforuseinavalve assembly as claimed in any of claims 1 to 29.

31. A thermostatic valve comprising a valve assembly as claimed in any of claims 1 to 28 in com bination with a thermostat attachment.