Note: Descriptions are shown in the official language in which they were submitted.
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Background of the invention
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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- ~-
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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.
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Summary of the invention
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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-
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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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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.
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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
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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.
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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
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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~.
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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.
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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.
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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
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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
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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
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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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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
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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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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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