Valve, especially a radiator valve

A radiator valve has a housing carrying a valve stem with plate and loading spring on the valve stem above the valve plate; a first seal bears against the valve stem between the valve plate and the spring. A presetting member is located in the housing and it carries a second seal bearing against the valve stem at a position removed from the valve plate with respect to the first seal.

FIELD OF THE INVENTION 
The invention relates to a valve, especially a radiator valve, having a 
pre-setting member and a loading spring for the valve stem, with at least 
two sealing rings, staggered in the longitudinal direction, bearing 
against the valve stem. 
PRIOR ART 
Valves of this kind are normally used as thermostat radiator valves and, 
for reasons of safety, they have two seals arranged one behind the other 
upon the valve stem, the second seal carrying out its function only when 
the first is no longer serviceable. Now, if the second, i.e. the outermost 
seal has to be replaced, this requires the removal of the loading, or 
tensioning, spring for the valve stem, and the withdrawal of other parts 
built into the valve. Since this is time consuming and therefore costly, 
it is the purpose of the present invention to provide a valve of the type 
described above, in which the second seal may be removed at no great cost, 
especially without removing the valve stem tensioning spring. 
SUMMARY OF THE INVENTION 
This purpose may be achieved in that part of the presetting member through 
which the valve stem passes is farther away from the valve plate, or the 
like, than the loading spring and the second sealing ring, which seals the 
presetting member in relation to the valve stem, comes automatically at a 
location on the valve stem outside the loading spring, i.e. it is farther 
away from the valve plate, or the like, than the loading spring. As a 
result of this, the second sealing ring may be replced without any 
difficulty by removing the presetting member, and all of the other 
internal parts, especially the loading spring, may be left in place. 
According to one particular preferred example of embodiment of the 
invention, the first sealing ring associated with the valve plate, or the 
like, is inserted into a cup-shaped element assembled, or more 
particularly screwed, into the neck area of the valve, the bottom of which 
separates the interior of the valve from the neck area. In this 
connection, and according to one very advantageous development of the 
invention, the bottom of the cup-shaped element rests upon a disc, the 
outside diameter of which corresponds to the diameter of the said bottom, 
and which is supported by a step or the like in the valve housing, the 
valve stem passing concentrically through the said disc and constituting, 
in conjunction with the bottom of the cup, an internal groove, i.e. a 
groove associated with the valve stem, for the first sealing ring. This 
provides advantages both in assembly and in production. From the 
production point of view, the advantage is that the radial groove is 
eliminated and a central passage for the valve stem is sufficient. From 
the point of view of assembly, this is simplified and accelerated by the 
fact that the sealing ring need be snapped into the retaining groove, but 
is merely placed in the expanded portion of the passage. 
The same advantages are provided in another configuration of the invention, 
in which the disc forms, in conjunction with the bottom of the cup, an 
external groove for a third sealing ring which seals off the cup-shaped 
element from the valve housing. The said disc need not necessarily be flat 
or of the same thickness over its entire width. 
According to another characteristic of the invention, the grooves for the 
second and fourth sealing rings are formed by the presetting member and at 
least one retaining member secured removably thereto. The design of the 
grooves is therefore comparable with that of the grooves for the first and 
third sealing rings. Here again it is possible for a common element to 
form the missing lateral surface for the two radial grooves. A point to 
which special preference is given here is that the retaining member is of 
a cup-shaped configuration, with one edge of the cup projecting outwardly 
and the valve spindle passing concentrically through the bottom of the 
cup. In this case the edge of the cup forms the lower or inner flank of 
the groove for the second sealing ring. The retaining member must be held 
immovably in the presetting member in some appropriate manner and, if 
necessary, it must be secured separately. For example, the connection may 
be made by means of an annular bead on the retaining member and a 
corresponding annular groove in the resetting member. Under certain 
circumstances, the friction between the two parts may be sufficient to 
hold them. Finally, a screwed connection is also possible.

DESCRIPTION OF A PREFERRED EMBODIMENT 
The said example of embodiment is a thermostatically controlled radiator 
valve, although the thermostat cap is not shown. The latter holds the 
closure element, in the form of valve plate 1, against the force of 
loading spring 2, in the form of a coil compression spring, in the closed 
position, in which it rests upon valve seat 4 which is integral with 
housing 3. 
Neck part 5 of valve housing 3 has an internal thread 6 into which a 
cup-shaped element 7 is screwed, and bottom 8 of the cup, through which 
valve stem 9 passes concentrically, thus separates interior 10 of the 
valve from neck part 5. A circular disc 12 lies upon a step 11 in the 
housing, being pressed thereto by means of cup-shaped element 7. 
Screwed into internal thread 13 of cup-shaped element 7 is a presetting 
member 14 which is also cup-shaped, but is inverted in relation to element 
7, so that base 15 is at the top. Valve stem 9 passes concentrically 
through the said base 15 of presetting member 14. A first sealing ring 16 
and a second sealing ring 17 serve to seal off the valve stem passages 
through cup-shaped element 7 and presetting element 14. Groove 18 for the 
first sealing ring 16 is formed by a central bore passing axially through 
cup bottom 8 on the one hand, and by the inner edge of annular disc 12 on 
the other hand. A groove for second sealing ring 17 is obtained in a 
similar manner by means of a central recess on the inside of bottom 15 of 
presetting member 14 and a retaining member 19. The latter is also in the 
form of a cup bottom 20 thereof, through which valve stem 9 passes 
concentrically constituting the lower side of groove 19. 
The outer edge of disc 12, in conjunction with a peripheral groove of 
rectangular cross section at the outer edge of bottom 9, forms a groove 21 
for a third sealing ring 22. A fourth sealing ring 23, located in a groove 
24, is held in a similar manner, the said groove being formed by the 
radially outwardly projecting edge 25 of retaining member 19 and another 
peripheral channel of rectangular cross section at the edge of presetting 
member 14. 
Valve interior 10 is sealed off by first sealing ring 16 and third sealing 
ring 22. If the said first sealing ring fails, the medium, for example hot 
water, can enter chamber 26. Second sealing ring 17 and fourth sealing 
ring 23 prevent the medium from flowing out of chamber 26. One end of 
loading spring 20 bears against bottom 8 of cup-shaped element 7, while 
the other end bears against a collar or circlip 27 on valve stem 9. The 
distance between circlip 27 and the inside of bottom 15 of presetting 
member 14 also corresponds to the maximal lift of valve plate 1. This lift 
may therefore be altered by screwing in presetting member 14 to a greater 
or lesser extent. Retaining member 19 has an outwardly projecting, 
peripheral, annular head 28 engaging with a corresponding annular groove 
in presetting member 14 and is thus locked. These two parts may also be 
locked together in some other known and appropriate manner. 
Assembly of the four sealing rings 16, 17, 22, and 23 is simplified by the 
use of disc 12 and retaining member 19. The same also applies to the 
machining of the sealing grooves for cup-shaped element 7 and presetting 
member 14.