GB2411449A

GB2411449A - Heating thermostat top part

Info

Publication number: GB2411449A
Application number: GB0503839A
Authority: GB
Inventors: Bjarne Frederiksen; Stig Andreasson; Egon Bastrup Christensen
Original assignee: Danfoss AS
Current assignee: Danfoss AS
Priority date: 2004-02-25
Filing date: 2005-02-24
Publication date: 2005-08-31
Anticipated expiration: 2025-02-24
Also published as: DE102004009197B3; RU2005104628A; CN1673643A; RU2293921C2; GB2411449B; GB0503839D0; RU2293921C9

Abstract

A heating thermostat top part (1) has a housing (2), a rotary control (3), which is rotatably arranged on the housing (2) and surrounds the housing (2) for at least part of its axial length, and a housing ring (19), which projects from the end of the housing (2) facing away from the rotary control (3). The housing ring (19) has a fixing profile (20; 34, 35) with which the housing (2) can be fixed on a fixing surface (23).

Description

2411 449 Heating thermostat top part The invention relates to a heating

thermostat top part with a housing, a rotary control, which is rotatably arranged on the housing and surrounds the housing over at least part of its axial length, and a housing ring, which projects from the end of the housing facing away from the rotary control.

Such heating thermostat top parts are meant for so called "LST radiators", that is, radiators with a low surface temperature. Such radiators are known from GB 2 259 758 A. That document shows a radiator in the form of a heat exchanger, through which, in a manner known per se, hot water flows as heat-transfer medium. This radiator is surrounded by a housing which does not assume the temperature of the heating water, but remains at a lower temperature. This constitutes an attempt to prevent a person unintentionally touching the radiator from suffering burns. The abbreviation "LST" here stands for "Low Surface Temperature", that is, implying a low surface temperature of the radiator.

Such a radiator should be also controlled by a thermostat top part, that is, it is desirable to preset a desired temperature for the room temperature, on the basis of which the flow of heat-transfer medium through the radiator is to be controlled. For this purpose, a conventional thermostat top part, as known from, for example, DE 102 11 131 Al, is fixed externally to the housing of the LST radiator. As, strictly speaking, this thermostat top part is meant for mounting on a radiator valve or a corresponding fitting, a corresponding adapter fitting must be fitted on the housing of the LST radiator.

This causes the thermostat top part to project rather far into the room, and parts of the thermostat top part are exposed to the environment, so that they tend to get dirty.

The invention is based on the problem of improving the visual appearance of: a thermostatic top part for an LST radiator.

The present invention provides a heating thermostat top part comprising: a housing, a rotary control rotatably arranged on the housing and surrounding the housing for at least part of its axial length, and a housing ring which projects from the end of the housing facing away from the rotary control, wherein the housing ring has a fixing profile, with which the housing can be fixed on a fixing surface.

With a thermostat top part as mentioned in the introduction, the abovementioned problem is solved in that the housing ring has the fixing profile with which the housing can be fixed on a fixing surface.

Thus, it is possible to bring the housing of the thermostat top part substantially closer to the fixing surface. In a manner of speaking, the housing ring forms the connection between the housing and the fixing surface.

Gaps between the fixing surface and the housing ring are therefore avoided. The length, with which the thermostat top part projects from the fixing surface, can also be reduced, so that the thermostat top part is less conspicuous in the room. The connecting element previously required can also be omitted so that a visible fixing no longer exists.

Preferably, the fixing profile is formed on a surface that extends parallel to the axial direction of the housing. Thus, it is possible to hold the thermostat top part fixed virtually around its complete circumference, that is, not just at points, as has been the case until now when three or four screws were used.

Preferably, the housing ring extends axially beyond a base element, which is axially displaceable in the housing by turning the rotary control and forms a support for a volume changing device of a temperature sensor element of the thermostat top part. In the thermostat top part is located a temperature sensor element having a filling, the volume of which changes in dependence on the prevailing temperature. Via a capillary tube, the temperature sensor element is connected with an actuation element located on the actual valve of the radiator. To adjust the desired value setting, the volume of this temperature sensor element is changed. For this purpose, the temperature sensor element is provided with a recess which is defined by bellows. A tappet projects into this recess. By axial displacement of this tappet, the tappet can now be moved to a greater or lesser extent into the interior of the temperature sensor element, so that it displaces a greater or lesser volume of the filling. The displacement of the tappet takes place by means of the base element. When it is now ensured that the base element is received virtually completely within the housing, this base element does not interfere with the mounting of the thermostat top part on the fixing surface. The space inside the housing ring remains free, so that there is greater freedom of design for the radiator. Thus, for example, when using the thermostat top part in an LST radiator, the distance between the heat exchanger itself and the housing can be made smaller, which in turn has a favourable effect on the LST radiator efficiency.

Preferably, the temperature sensor element is fixed so as to be axially and radially immovable in the housing.

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Thus, turning of the rotary control in relation to the housing causes no change in the axial dimensions of the thermostat top part. On the contrary, the volume change of the temperature sensor element occurs exclusively as a result of movements inside the housing. The temperature sensor element is completely surrounded by the housing, so that the housing protects it.

Preferably, the housing has a diametral enlargement outside the rotary control, the housing ring being located on this diametral enlargement. This provides a fixing option with a relatively large lever arm, which has a favourable effect on the fixing of the thermostat top part on the fixing surface. With regard to a thermostat top part it must be assumed that users will repeatedly operate the rotary control to effect a change in the desired value.

This turning of the rotary control in relation to the housing results in a torsional moment on the connection between the housing and the fixing surface. Therefore, the larger is the lever arm, with which this connection can counteract the torsional moment, the better is the thermostat top part retained on the fixing surface.

Further, this construction has the advantage that the diametral enlargement can cover the front side of the rotary control. The gap that is practically unavoidable between the housing and the rotary control can therefore be kept small. The risk that dust will penetrate between the rotary control and the housing and contaminate the inside of the thermostat top part is dramatically reduced.

Also, places in which dust could otherwise gather, and which are difficult to clean, are largely avoided. It is therefore easier to keep the top part clean, and its tendency to become dirty is reduced.

Preferably, the housing has an axial stop adjacent to the housing ring. Thus, an Immediate correlation of the fixing surface to the housing in the region of the housing ring is possible. This increases the stability of the fixing. Tilting moments, which could act upon the thermostat top part, are reliably absorbed.

Preferably, the fixing profile and the axial stop have a predetermined spacing from each other. In connection with an LST radiator, the thermostat top part is fixed on a fixing surface, which is formed by a thin plate, for example of sheet metal or the like. When now a space is provided between the fixing profile and the axial stop, which space corresponds to the thickness of this plate, then this plate is accommodated and fixed between the fixing profile and the axial stop. Fixing of the thermostat top part on the plate is then only possible from the "rear" of the plate, that is, not from the side on which the rotary control is located. This provides improved protection against theft of the thermostat top part.

Preferably, at least one element of an anti-rotation device is located on the housing ring. As mentioned above, torques act upon the housing via the rotary control, which are effectively absorbed by an anti-rotation device. An anti-rotation device can be realized, for example, in a simple manner in that the housing ring has a projection engaging in a corresponding recess in the outline of an opening, in which the housing ring is inserted. The anti- rotation means also ensures the correct orientation of the top part on the radiator. For example, it may be ensured that a setting mark always points upwards.

Preferably, the fixing profile has a circumferential groove, in which a spring retaining ring engages. In this case, the thermostat top part is fixed on the plate in that the housing ring passes through an opening in the plate. As soon as the groove is accessible on the rear of the plate, a retaining ring can be inserted, so that the thermostat top part IS fixed. Instead of the spring retaining ring, a different element can be used to fix the top part on the mounting surface.

In an alternative or additional embodiment, the fixing profile can have at least one locking element. In this case, it may be expedient for the housing ring to be divided into several individual sections in the circumferential direction. During insertion, the locking elements may, for example, yield radially inwards. As soon as the axial stop has engaged on the plate, the locking elements can yield radially outwards again. The thermostat top part is then held securely on the plate.

Removal of the thermostat top part is then only possible when the locking elements are pressed together from the rear of the plate.

In a further alternative, an adapter element can be secured in the housing ring. Such an adapter element is particularly advantageous when the opening, which is provided in the fixing plate for receiving the thermostat top part, does not correspond to the diameter of the housing ring. Many manufacturers of LST radiators prefer an opening the diameter of which is smaller than the diameter of the housing ring. Here again, however, it can be ensured that the thermostat top part is reliably fixed on the fixing plate, namely by means of the adapter element.

Preferably, the adapter element is connected with the housing by means of a bayonet connection. A bayonet connection is easily manufactured, that is, the adapter element merely has to be inserted in the housing ring by means of an axial movement, and then turned through a predetermined angle. The adapter element IS then fixed in the housing ring.

Preferably, the adapter element has a portion of a larger diameter and a portion of a smaller diameter, the portion with the larger diameter being located axially completely within the housing ring. When, now, the adapter element is fixed on the fixing surface, for example by means of a screwed connection, the housing ring is pulled towards the fixing surface. Rotational movement of the housing in relation to the fixing surface is then prevented by the friction between the housing ring and the fixing surface. This also provides an effective theft protection for the thermostat top part.

For fixing the adapter element, it may be advantageous to use a first axial movement, a subsequent rotational movement, and finally a second axial movement opposite to the first axial movement. In this case, when the housing has engaged the fixing surface via the adapter element, it will no longer be possible to remove the thermostat top part when the adapter element is fixed on the fixing surface.

Heating thermostat top parts constructed in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 shows a first embodiment of a heating thermostat top part; Fig. 2 shows a second embodiment; - 8 - Fig. 3 shows a third embodiment; and Fig. 4 is a schematic view illustrating a bayonet connection.

Referring to the accompanying drawings, Flg. 1 shows a heating thermostat top part 1 with a housing 2, on which a rotary control 3 is rotatably mounted, yet is fixed in the axial direction. For this purpose, the housing 2 has a circumferential groove 4, in which a projection 5 on the inside of the rotary control 3 engages. The rotary control surrounds the housing 2 for the major part of its axial length.

In the housing 2 is located a temperature sensor element 6, which surrounds a chamber 7 that is filled with an expansible material, that is, a material, whose volume changes in dependence on temperature. This material may be a liquid or a gas. Via a capillary tube 8, the chamber 7 is connected with an actuating element 9, which is fixed on and actuates a valve (not shown) of a radiator.

The temperature sensor element 6 has a recess 10 which is bounded by a bellows-forming wall 11. A tappet 12 is inserted in the recess 10, said tappet resting on a base 14 via a spring 13. The base 14 is non-rotatably mounted in the housing 2 and engages with radially extending arms 15 in an inner thread 16 of the rotary control 3. Thus, rotation of the rotary control 3 in relation to the housing 2 displaces the base 14 in the axial direction. At the same time, the tappet 12 is displaced to a greater or lesser extent so that it changes the volume of the chamber 7 by deformation of the bellows- forming wall 11. This results in a desired value setting, which is known per se. - 9 -

For the sake of completeness, it must be noted that the housing 2 completely surrounds the temperature sensor element 6, so that the temperature sensor element 6 is protected by the housing 2. However, the housing 2 can have openings 17, through which the room air can act directly upon the temperature sensor element 6.

For reasons of clarity, the end of the housing 2 on which the temperature sensor element 6 is located is here called the "upper end". At the opposite, lower end, the housing 2 has a diametral enlargement 18, on whose radial outside a housing ring 19 is formed. On the radial outside of the housing ring 19 is located a circumferential groove 20, in which a spring retaining ring 21 is inserted. The diametral enlargement 18 forms an axial stop 22. A plate 23, which forms a part of a radiator cover of an LST ("Low Surface Temperature") radiator, is thus held between the axial stop 22 and the retaining ring 21 and forms a fixing surface. The retaining ring 21 surrounds the housing ring 19 over the major part of its circumference. On the housing ring 19 is located a marker clip 24, which, for example, represents a setting mark. In the region of this marker clip 24, the retaining ring 21 is interrupted.

For mounting the thermostat top part 1, the housing ring 19 is simply inserted in an opening 25 in the plate 23. From the opposite side, the spring retaining ring 21 is inserted in the groove 20 and the thermostat top part 1 is fixed in the plate 23. In this connection, the spacing between the groove 20 and the axial stop 22 is exactly the same size as the thickness of the plate 23. Accordingly, the thermostat top part 1 is fixedly held in the plate 23 in the axial direction. As the retaining ring 21 is neither visible nor able to be manipulated from the side - 10 - from which the thermostat top part l is accessible, the retaining ring forms an anti-theft means for the thermostat top part 1.

Although not shown, the opening 25 has an ndent in which a corresponding projection on the housing ring l9 engages. In this way, the thermostat top part l, or rather its housing 2, is secured against rotation in relation to the plate 23.

Fig. 2 shows a modified embodiment, in which the same lO or functionally the same elements have the same reference numbers. The actuation element 9 is not shown here.

In the embodiment according to Fig. 2, the housing ring l9 is provided with several locking elements 26, which are uniformly distributed in the circumferential direction. The housing ring l9 can also be made mainly or exclusively of locking elements 26. For mounting, the thermostat top part l with the housing ring l9 is simply inserted in the opening 25 in the plate 23. An axial pressure deforms the locking elements 26, which have an inclined outside 27, resiliently inwards. As soon as the housing ring l9 has been inserted axially so far into the opening 25 that the plate 23 can enter the groove 20, the locking elements 26 spring radially outwards again, so that the thermostat top part l is fixed in this manner.

Deformation of the locking elements 26 from the side of the plate 23 from which the thermostat top part l projects, is not possible. Thus, the arrangement with the locking element 26 forms effective anti-theft means.

The embodiment of the thermostat top part l is otherwise identical to that shown in Fig. 1.

In the embodiments according to Figs. l and 2, the thermostat top part l is inserted with a part of the housing ring l9 into the plate 23, so that it has a - 11 - rclatively small overall height, that is, merely projects to a small degree from the plate 23.

Llg. 3 shows an embodiment in wElch the thermostat top part projects somewhat further from the plate 23.

Here again, the same parts have the same reference numbers as in Flgs. 1 and 2.

The plate 23 now has an opening 25, whose diameter is smaller than that of the openings shown in Figs. 1 and 2.

There, the opening 25 was approximately the same size as the diametral enlargement 18 of the housing 2.

To ensure that a thermostat top part 1 can still be used in a practically unchanged manner, an adapter element 28 is provided, which has a portion 29 of a smaller diameter and a portion 30 of a larger diameter. Here, the capillary tube 8 is twice bent at an angle so that it can be led through the adapter element 28.

The axial length of the portion 30 of larger diameter is smaller than the length available inside the housing ring 19, so that the portion 30 of larger diameter can be completely received within the housing ring 19.

The adapter element 28 is connected with the housing 2 via a bayonet connection, which will be explained by means of the detail 31.

The bayonet connection has an axially extending groove 32 inside the housing ring 19, into which a projection 33, which is located on the outside of the adapter element 28, or rather on the outside of the portion 30 of larger diameter, can be inserted, so that the adapter element 28 can be inserted axially into the housing ring 19 over a certain distance. The axially extending groove 32 merges into a circumferential groove 34, which is adjoined at its end by a second axial groove 35, whose length is, however, substantially less than the length of the first axial groove 32.

To mount the adapter element 28 on the housing 2, the adapter clement 28 is therefore aligned with the housing ring 19 in such a manner that the projections 33 can be inserted into the axial grooves 32. Subsequently, the adapter element 28 is moved so far into the housing ring 19 that it comes to rest on the axial stop 22. Then, the adapter element 28 is turned in relation to the housing ring 19, the projections 33 moving along the circumferential groove 34. At the end of the circumferential groove 34, the adapter element 28 is pulled a little way out of the housing ring 19, resulting in the position shown in Fig. 3.

When the adapter element 28 is now fixed on the plate 23 by means of a nut 36, the housing ring 19 rests on the fixing surface of the plate 23. Movement of the adapter element 28 further into the housing 2 IS not possible, so that the bayonet connection cannot be released.

Fig. 4 shows the opening 25 in the plate 23, which has a swell 37. A projection 38 extends into the indent 37, the projection 38 being formed on the adapter element 28. In this manner, the adapter element 28 is held non rotatably in the plate 23. As the adapter element 28 can only be connected with the housing 2 in four different positions, as can be seen from Fig. 4, it is ensured that the thermostat top part 1 can always assume a predetermined alignment in relation to the plate 23.

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Claims

C. I. A I M S: 1. A heating thermostat top part comprising: a housing, a

rotary control rotatably arranged on the housing and surrounding the housing for at least part of its axial length, and a housing ring which projects from the end of the housing facing away from the rotary control, wherein the housing ring has a fixing profile, with which the housing can be fixed on a fixing surface.
2. A thermostat top part according to claim 1, wherein the fixing profile is formed on a surface that extends in parallel to the axial direction of the housing.
3. A thermostat top part according to claim 1 or 2, wherein the housing ring projects axially beyond a base element, which is axially displaceable in the housing by rotation of the rotary control and forms a support for a volume changing device of a temperature sensor element of the thermostat top part.
4. A thermostat top part according to claim 3, wherein the temperature sensor element is fixed so as to be' axially and radially immovable in the housing.
5. A thermostat top part according to any one of claims 1 to 4, wherein the housing has a diametral enlargement outside the rotary control, and the housing ring is located on this diametral enlargement. - 14
6. A thermostat top part according to any one of claims l to 5, wherein the housing has an axial stop, which is adjacent to the housing ring.
7. A thermostat top part according to claim 6, wherein the fixing profile and the axial stop have a predetermined spacing from each other.
8. A thermostat top part according to any one of claims 1 to 7, wherein at least one element of an anti-rotation device is located on the housing ring.
9. A thermostat top part according to any one of claims 1 to 8, wherein the fixing profile has a circumferential groove, in which a spring retaining ring engages.
10. A thermostat top part according to any one of claims 1 to 8, wherein the fixing profile has at least one locking element.
11. A thermostat top part according to any one of claims 1 to 8, wherein an adapter element is secured in the housing ring.
12. A thermostat top part according to claim 11, wherein the adapter element is connected with the housing by means of a bayonet connection.
13. A thermostat top part according to claim 12, wherein the adapter element has a section with a larger diameter and a section with a smaller diameter, the section with the larger diameter being located axially completely inside the housing ring.
14. A thermostat top part according to claim 12 or 13, wherein for fixing the adapter element a first axial movement, a subsequent rotation movement, and finally a second axial movement oppositely to the first axial movement are required.
15. A heating thermostat top part substantially as herein described with reference to, and as illustrated by, Figure 1 of the accompanying drawings.
16. A heating thermostat top part substantially as herein described with reference to, and as illustrated by, Figure 2 of the accompanying drawings.
17. A heating thermostat top part substantially as herein described with reference to, and as illustrated by, Figures 3 and 4 of the accompanying drawings.