CA1045099A

CA1045099A - Thermostat unit for central heating radiators

Info

Publication number: CA1045099A
Application number: CA237,382A
Authority: CA
Inventors: Fingal Christiansson
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-10-22
Filing date: 1975-10-06
Publication date: 1978-12-26
Also published as: AT341153B; FI752922A; IT1043353B; CH606886A5; NO143176B; FI60770B; DK450075A; GB1524869A; NO143176C; FR2288925A1; FI60770C; NO753542L; FR2288925B1; DD122424A5; ATA792875A; DE2546213A1; NL7512300A; JPS5164743A

Abstract

A B S T R A C T

An individual thermostat unit for the valve housing of a central heating radiator replaces the conventional radiator valve mechanism and affords a simplified mounting without the need for modifications of pipe connections. This thermostat unit comprises two setting means, one for basic settings, and another for temperature settings. A setting knob gives different tempera-ture settings by being turned on a thread. This same thread per-mits the setting knob to be screwed off as part of the housing of the unit, to make the basic setting means accessible when mounting the unit in a valve housing.

Description

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Background of the invention .
The need for an individual automatic temperature control in central-heated localities is felt to an increasing degree with the continued raise of the energy costs. In central heating systems an individual thermostatic control of the different radiators has hardly been a ~easible attainment. The priorly known thermostat units require, for installation, rather extensive changes of the radiator connect- ~-., ~ ., .
ions, and having regard to the fact that all radiators in operationbelonging to a building must be equipped with thermostat units if D the full profit of the thermostatlc control is to be attained, the necessary installation work may well be too extensive and costly to be deemed ~ustifiable and co~pensated for by future savings.
~ ~ -Summary of the invention . .
It is a chief object of the invention, therefore, to provide a ~ -thermostat unit which can be mounted without any special adjustment work, by way of a simple substitution of the thermostat unit for the originally installed radiator valve mechanism. It is a further object of the invention to provide a thermostat unit affording double settingmeans which do not interfere with each othèr, one ~being for basic settin~Ciand the other for current temperature settings.

It is a still further object to make the basic setting means in-' ~045~99 accesslble ~rom the outside and accessible only by dismounting a setting knob for temperature settings.
It is a still further object to provide means pre-venting any unauthorized adjustment or unscrewing of the tem-perature setting knob save a restricted adjustment in the , retrograde, i.e. temperature-lowering sense.
In accordance with one embodiment, a thermostat-con-; trolled valve mechanism for mounting in a conventional radiator valve housing comprises, a valve spindle operable to be moved towards the valve closing position by a temperature sensing body against the action of a compression spring, said valve spindle having an axially adjustable extension fitted thereto, said compression spring being mounted between a stationary portion of the valve mechanism and the said axially adjustable extension to have its length and thereby its amount of pre-compression altered upon relative axial adjustment of said spindle extension.
DRAWING
Fig. 1 is a longitudinal section of a first embodiment, and Fig. 2 is an elevation view of the same unit on a smaller scale and mounted to a radiator valve housing.
Fig. 3 is a longitudinal section of a second embodiment, -and Fig. 4 is a similar section of a third embodiment, the ~`
setting knob with the sensing member having been left out.
Fig. 5 is an exploded view of a fourth embodiment suited for installation in heating systems employing radiator valves with an external coupling thread.

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DESCRIPrrION
Reference numeral 1 denotes a body or bush member of brass or other suitable metal comprising a neck portion l_ with external thread and a radial flange portion lb from which there extends in the opposite direction of the neck la an inner axial flange lc and an outer axial flange ld. The flange lc surrounds ~
a central bore le in which a cylindrical member 8 is guided for ;
axial travel, said member 8 forming a screwed-on extension of a i:
valve stem 16 `.: .'. :
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-` ~L0~5~99 which extends through the bore and out rrom the neck la and carries at its free end a rubber member 14 supported by a rigid washer 15 and secured by a nut 13. The elements 13, 14, 15 form a valve member denoted hereafter 14 and capable of engaging or disengag-ing a seat in a valve housing 20 mounted. in the usual manner in the - inlet conduit of a non-illustrated central heating radiator, there bein~ in conventional installations a valve mechanism or assembly screwed into said valve housing, to be replaced by the thermostat unit. The passage of the valve stem 16 through the neck la is 3 sealed by means of 0-rings 2 and 17, respectively. The 0-ring 2 (or rather two rin~s) is received in a recess in the neck la which is c]osed by a washer 3 having a hole therein for the passage Or the stem. In the free portion of the bore le a compression spring 4 is lodged, which is precompressed in such a manner that it will urge the valve stem in the opening direction by acting against the member 8. If the bush 1 with the parts mounted thereon is screwed into the valve housing 20, the valve member will cooperate with the valve seat in the housing and will control the fluid flo~ to the radiator by assuming different axial positions. The outer axial ~flange ld of the bush 1 is formed with an external thread, and the radial flan~e lb has a polygon shape, preferably hexagonal. This flange is surrounded by an annulus 6, preferably Or plastic, where-of the inner circumrerence has a corresponding poly~on shape. This annulus is capable of sliding axially along the flange lb, but is prevented to rotate by reason Or its angular shape. The end face of the annulus 6 remote from the valve member is forme~ with teeth 6a for a purpose ~o be described presently. Cornpression springs 5 are lodged in recesses in the annulus wall, and oppose axial move~

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ment of the annulus to the left in the drawing. Such movements are finally checked by a shoulder 6b within the annulus ~Jhich is shown in Fig. 1 as having abutted the flange lb.

Onto the threaded portion of flange ld a setting knob 7 is screwed.
It is shaped substantially as a truncated cone with an internal thread at the large end mating with the flange thread. The knob 7 is formed with a longitudinal bore with a stepwise reduced diameter.
At its larger end face the knob is formed ~Jith teeth 7a mating with the teeth Or the annulus 6. When these teeth are in interlocking engagement, the knob is held against rotation, and it can be turned only ir the annulus 6 is urged back against the spring loading, that is towards the left in the drawing. Upon being rotated, the knob is displaced axially by virtue of its threaded engagement ~lith -the flange ld.
' , ' Within the bore o~ the knob 7 there is lodged a temperature-sensing member 10, preferably a wax element. This sensing member has an axially extending pin lOa moving lo~itudinally on temperature variations. This pin may be guided laterally by a bush 9 rixed to ~ , .
the sensing member, ror increased stiffness. The sensing member is ~0 held against rearward displacement by a compression spring 11 abutt-ing an end plug 12 screwed into a thread rormed in the bore Or the knob. The compression spring 11 is stronger than~compression spring 4~ and its normal state is one Or non-compression.
,', The pin lOa engages by its free end the cylindrical member or valve stem extension 8, and the force exerted by the sensing member and ," ~, '. ''' ' ' ' ' " . '. i ,' ~, ' ,' ' ' ' , ' : , . ' ,, ; .. , ' ,: , . . . .

S~9g the spring ll, respectively, displaces the valve member 14 towards or away from the valve seat in dependence of temperature variations, and accordingly controls the fluid flow through the radiator. The temperature setting is changed by turning the knob after pushing back the annulus 6. The arrangement is "childproof" since setting adjustments require a coordinated action of both hands.

~or minor adjustments of the thermostat settings the plug 12 may be turned by engaging a coin in the slot 12a, the size of the coin preventing,any excessive inward adjustment. For a datum setting D the axial adjustability of the member 8 relative to the valve stem 16 is used. These parts being connected by mating threads are capable Or relative longitudinal adjustment by being rotated relative to each other. For this adjustment, setting knob 7 must be screwed off. `

The outer wall of the knob 7 is broken through by a plurality of slits 21 (Fig. 2) to give free access of ambient air to the sensing ~
member. This will enable temperature variations to cause correspond- , ing displacements of the valve member.

The annulus 6 is provided with an index mark that may preferably be a screw 22 engaging a radial bore extending through the wall of the annulus. When a temperature setting has been selected by turning ~`
the knob 7, the large end of which is graduated as at 23, the annu-lus can be locked in its position by tightening the screw 22. The ,~
setting cannot be changed thereafter, unless the screw is untightene~.

v~s0g9 The compression sprin~ 11 supporting the sensing me~ber 10 protects the knob 7 from splitting if subjected to excessive heat such as by strong sun radiation. The additional expansion will be absorbed by the spring 11 being shortened.
' '', ' ' The thermostat unit now described is very simple to install as a replacement of valve assemblies already in operation. Any such measures as sawing orf piping and cutting new threads are unnecess-ary. The valve mechanism is simply screwed of~, and the thermostat unit isscrewed on, and is ready to control room temperature at the désired~level. Sealin~ between the bush 1 and the valve housing 20 may be attained by means of an O-ring 18 received in an annular - :--groove at the radially inner portion of the flange lb. Setting and adjustment is effected in the manner previously described, after the ;
positive engagement between ine knob 7 and the annulus 6 has been temporarily suspended, as described.
;,-The thermostat unit may easily be modiried into a valve mechanism without a thermostatic function, and vice versa. For that purpose the sensing member 10, the spring 11 and the plug 12 are replaced by a screw, preferably made of plastic, which is screwed into the thread of the knQb 7 at the outer end thereof, and which abuts with its ~ree end the member ~. On turning the knob, the valve member lli will travel axially due to the axial displacement between the knob ...
and the bush 1. Ir radiators are equipped in this simpli~ied way ~rom the outset, it is further faci]itated to provide thermostatic control at a later stage by substituting the aforesaid components ''., ~ ., .7 ., ' .. - . . . .j , ., . ~ , , , "

' '' ' . ` : ', ' '' '' ' '` . ' ''. ' . .. , ' " " " ' ' I ~ " ' ' ' ' "' , ' . . , . ' l~SU~9 10, 11, 12 for the rigid screw.
A second embodiment of the thermostat unit is illustra-ted in Fig. 3.
This device is constructed in most essentials like the unit described in conjunction wi-th Figs. 1 and 2. Only those parts differing essentially from those of the first embodiment need be described, therefore.
Thus, the annulus 6 is formed with an axially extending rib or key 25 the purpose of which will be explained presently.
The setting knob 7 is formed at its inner end with a thickened rim at the end face of which the teeth mating with the teeth of annulus 6 are formed. At the cylindrical inner end portion of the knob an indexing ring 26 is mounted so as to be capable of axial and rotary relative movement. This ring has an axiallv projecting portion 27 with a keyway 28 therein for receiviny the rib 25. In the illustrated position, the rib en~ages the keyway, and the ring 26 thus is held against rotation relative to the annulus 6. This arrangement prevents the turning of setting knob 7 even after axial displacement of the annulus, against the power of the springs 5, to disengage the mating locking teeth. This result is attained by reason of the engagement between key 25 and keyway 28 and by the indexing ring being rigidly locked to the setting knob by means of a set screw 22 held in a threaded radial bore in a thickened portion of the ring 26 The head of the set screw may be sealed to prevent any unauthorized adjustment.
In Fig. 3, the setting knob has been illustrated as fully screwed home, that is, it has pushed the annulus 6 towards the left until the annulus 6 abuts the shoulder on the bush 1. ~;
However, as will be appreciated, in its operative position, the setting know would not be screwed home in this manner, and a good clearance would be left between the annulus 6 and the shoulder on the bush 1 . :~ - : `,.. . . ~. . . . . .. . .

4~i099 ', It may be desirable, ho~1ever, that the tenants of` an apartment build-ing should be able to set a lower temperature than the one corres-ponding to a fixed setting as described above. For that purpose, the engagement between the rib or key 25 and the keyway 28 is dispensed with. Instead, ~he abutment of rib 25 against one flank of the projecting portion 27 is used as a normal setting datum. The tenant will then be able to set a lower temperature (e.g. night temperature) by turning the knob 7 away from this end position, but he cannot set a higher temperature than the predetermined one by l~ turning the knob in the opposite sense.

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For a smooth operation of the valve membe~ and for avoiding disturb-ing noises otherwise common in radiator valves it is essential that the valve member can adjust itself to the valve seat in the valve housing. For that purpose, the valve stem 16 is shaped at its end with a thinner portion 29, and a metal ~lasher 30 is held by that portion with some clearance, to enable the washer to assume an ob-lique position. The outer end of the portion 29 is upset, to form a head, and the length of this portion inside the head is greater than ~-the thickness of the washer, to permit the ~asher to adjust itself. ~

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A sealing member 31 of rubber or like material having an overlapping rim is mounted over the washer and is held taut by the latter, thus affording a smooth resilient sealing surface against the valve seat.
This sealing member is easy to replace, if necessary. This embocli-ment lacks an adjusting plug at the small end of thesetting knob 7. `

The latter is formed with an integral rear surface, inst;ead.
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- 104S¢:~99 i Referring now to Fig. 4, numeral 1 again denotes a body or bush of brass or other suitable metal with a threaded neckc la for screwing into a radiator valve such as valve 20 in Fig. 2. The valve stem 16 passing through the bush 1 is guided by a central bore in the bush as well as by a washer 3 received in the widened central recess le Or the bush. The compression spring 4 abuts with one end the washer 3 and with the opposite end a setting member 40 corresponding to member 8 in Fig. 1. This member is prererably made Or plastic having a metal sleeve 41 molded into it. Internal threads in this D sleeve engage the threaded rear end portion Or the va~ve stem which extends into a central relier bore (not illustrated) in member 40.
By turning the setting member 40, the free end of which forms an abutment for the sensing member operating pin lOa (Fig. 1), the ~-~
member 40 will project a longer or shorter measure beyond the bush 1. This will permit, ror valve housings having a different distance between the valve seat and the abutting face of the socket of the valve housing into which the bush 1 is screwed, the spring 4 to be compressed to the same degree, and thus the spring force acting -against the force exerted by the sensing member will be equalized.
In practice this is effected in such a manner, that for the smallest- ~-sized valve for which the thermostat unit issuited, the setting member 40 will be set to a given reading on the scale 42, for ex- i-ample 15 millimeters. After this setting, and screwing the bush into the valve housing, a reading is talcen on scale 42 after urging the ~;~
valve stem to engage the valve member with the valve seat. If this ,~ :
reading is 12 millimeters on the scale the valve stroke will be 3 millimeters. For a larger-sized valve housing, a longer valve stroke ,. : . : . : : . :, , : : . .. . ,: , , ~, . .. .

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will be nece~ssary, but to the same final length of the spring 4.
In this instance the setting member is screwed outwards for example to a reading of 17 on the scale whereas the reading ror the shut valve would still be 12. The valve travel will be longer, but the operating force will remain unchanged.

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The setting member 40 preferably has a polygonal cross section, such as hexagonal, to afford a sure grip when being turned and to offer a flat background to the scale 42. The readings are best taken along the end face of the axial flange lc of the bush.

~D It should be appreciated that the setting arrangement now described will greatly facilitate an adequate adjustment from the outset and a simple adaption to different-sized radiator valves ~Jhich may be effected on installation of the thermostat unit without the need `~
for additional measures before or after.

Another embodiment of the termostat unit illustrated with the ex-ploded view in Fig. 5 differs from those already described mainly by being adapted for mounting on a valve housing 50 having an external coupling thread 5Z for engaging a union nut 60 separate from the unit as such. This wi31 facilitate the mounting of the unit in a ~o valve housing at which the nut 60 has previously served to secure the conventional valve mechanism. `

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To malce this kind of mounting possible, the body or bush 1 of the embodiments already described has been replaced by a valve stem guide ~;~
member 53 and a bush member 54. The member 53 is formed with a ~,. .
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O~S~99 radial ~lange 55 for sealing against the rim of the valve housing socket 51, an 0-ring 56 being interposed as a seal. The nut 60 is formed with a shoulder for clamping the flange 55 to the valve housing, and an external thread 57 cut on guide member 53 receives the internally and externally threaded bush member 54. In all other respects this embodiment is equal to the embodiments illustrated in Figs. 3 and 4.

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The chief advantage of this embodiment is that the union nut 60 of the existing radiator valve will be used thereby dispensing with the \~ practically non-feasible task of manufacturing the units so as to .
fit the threads and dimenslons of valve housings having an external coupling thread, as such housings are often provided with absolete ..
and non-standardized threads. This difficulty does not appear, as a rule, in valve housings having an internal coupling thread, .
when mounting thermostat units such as described with reference to Figs. 1 to 4. .:-;
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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. A thermostat-controlled valve mechanism for mounting in a conventional radiator valve housing, said mechanism com-prising a valve spindle operable to be moved towards the valve closing position by a temperature sensing body against the action of a compression spring, said valve spindle having an axially adjustable extension fitted thereto, said compression spring being mounted between a stationary portion of the valve mechanism and the said axially adjustable extension to have its length and thereby its amount of pre-compression altered upon relative axial adjustment of said spindle extension.

2. A valve mechanism as claimed in claim 1, wherein the relative axial position of the said valve spindle extension is indicated by a marking provided on said extension.

3. A valve mechanism as claimed in claim 2, wherein said valve spindle extension has a polygonal cross section shape, said marking being a graduation provided on at least one polygon face thereof.

4. A valve mechanism as claimed in claim 1, wherein the said valve spindle is slidably guided within a guide member having a front end portion formed with an external thread for screwing into an internal thread belonging to a radiator valve housing.

5. A valve mechanism as claimed in claim 1 wherein the said valve spindle is slidably guided within a guide member formed with a radial flange capable of being engaged by a union nut for mounting said guide member onto a radiator valve housing having a mating external thread.