Note: Descriptions are shown in the official language in which they were submitted.
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The invention re ates to a sin,gle-handle, sanitary mixlng
valve having control elements composed of at least two discs,
one of which serves as a fixed valve seat disc with two inlet
openings for cold and hot water, while the second disc, movably
disposed on the valve seat disc, has a control edge that at
least partially reduces the free flow area for cold water at
the inlet opening when the movable disc is shifted to its
central position by the operating handle, as compared to the
corresponding free flow ar~ of the hot water inlet opening of
~10 the fixed valve seat, in the mixed water temperature ranges
conventionally bounding a so-called comfort zone.
When mixing fittings are operated in combination with
thermally or hydraulically controlled flow heaters, malfunc-
tions often occur in the ordinary mixed water temperatures
because the heaters require certain minimum flow rates. If
these minimum flow rates are not maintained, the heaters will
switch off in whole or in part.
To avoid such malfunctions, there are known single-handle
mixing valvesof the type described in which the mixing chamber
opening in the movable disc is asymmetrically shaped relative
to a symmetrical port configuration in the fixed valve seat
disc, to ensure tha~ the free flow area at the inlet opening
for cold water is smaller than on the correspondin~ hot
water side in the mixed water temperature ranges. Such a
; ~,''`' ~
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mixing valve, from which the present invention departs, is
disclosed in German patent publication No. 33 10 ~80-A. It
has proved successful in practice. A disadvantage of the ~.nown
devices is that the movable disc, o,wing to the special
configuration of the mixing chamber opening, must be a special
part, that is, differing from the corresponding discs of
conventional single-handle mixing valves.
With the foregoing in mind, an object of the invention is
to provide a sanitary mixing valve wherein the movable disc may
be of conventional configuration or the fixed valve seat disc
may be of conventional configuration. Another object of the
invention is to provide a mixing valve, in combination with
thermally or hydraulically controlled flow heaters, which is
simple in construct and easy to manufacture, and affords
reliable operation.
The sanitary mixing valve of the present invention
provides that the centroids of the port areas of the inlet
openings in the fixed valve seat disc, or at least the centroid
of the port area of the inlet opening for cold water, are
shifted a few degrees of angle toward the cold water setting in
order to achieve hydraulic asymmetry in the central positions
of the operating handle.
According to one form of the invention, the conventional
configuration of the movable disc is unmodified while the inlet
opening for hot water is made larger than the inlet opening for
cold water so that hydraulic a~try is achieved when the
handle is in its central position.
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According to another form of the invention, the inlet
opening for cold water is made kidney-shaped; the interior edge
of the opening is drawn inwardly.
According to still another fo~m of the invention, the
lengthwise axis of the inlet opening for hot water is greater
than the axis of the inlet opening for cold water.
A further form of the invention provides that the control
edge of the movable disc reduces the free flow area at the
inlet opening of cold water, when compared to the corresponding
area of the hot water opening, so that the centroid of the port
area of the inlet opening for c~ld water is shifted radially in
the direction of opening of the control edge of the movable
disc relative to the inlet opening for hot water.
In the drawings, the subject matter of the invention is
represented in three embodiments by way of example where:
FIG. 1 is a schematic representation of the single-handle
mixing valve of the present invention, operably coupled to a
flow heater;
~ FIG. lA is an elevational view, in section, of a single-
handle mixing valve in its opened position, shown in FIG. l;
FIG. lB is a view similar to FIG. lA, but in its closed
position;
FIG. lC is a top plan view with the single-handle mixing
valve in its full mixing position;
FIGS. 2A and 2~ are bottom plan views of the fixed valve
seat disc and movable disc, according to an embodiment of the
invention;
~3~
FIGS. 3A to 13A are bottom plan views of the fixed valve
seat disc and movable disc of FIGS. 2A and 2B in full assembly,
wi~h tha movable disc of FIG. 2B shown in various functional
positions of the valve assembly, n~mely, FIG. 3, its closed
position, FIGS. 4A-4B through 7A-7B, hot water positions, FIGS.
8A-8B to 13A-13B, its cold water positions;
FIGS. 3B-13B are sectional views, in elevation, of the
respective views of FIGS. 3A-13A, which illustrate water flow
through the valving assembly, as seen by following the -
direction of the arrows;
FIGS. 14A-14B are another embodiment of the valve
assembly shown in FIGS. 2A-2B; and
FIGS. 15A-lSB are a further embodiment of the invention,
as shown in FIG~ 2A-2B.
FIG. 1 illustrates, schematically, a single-handle mixing
valve assembly 10, operably coupled to a flow heater 12 by hot
water conduit 14 and cold water conduit 16. Main water supply
conduit 11 is coupled to flow hot water heater 12 and cold
water conduit 16 through "T" coupling 15.
Mixing valve 10 includes a valve housing 20 in which valve
cartridge 22 is arranged with control elements having two valve
discs 24 and 26. Disc 24 is fixed in cartridge 22 and serves
as a valve seat. Fixed disc 24 is formed with an inlet opening
21 for hot water and an inlet opening 23 for cold water, as well
as an outlet opening 25 for mixed water leading to spout 13 of
mixing valve assembly 10.
FIGS. 2A, 2B through 13A, 13B illustratei in bottom plan
views and sectional view in elevation, respectively, fixed disc
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24 and movable disc 26 in their various respective operative
positions from fully closed to fully opened, shown by the
direction of the arrows in sectional views, in elevation, of
FIGS. 4B through 13B. Movable disc 26 is shown in dotted line.
Also, the position of handle 18 is shown by the arrow above
each view of the valve discs in plan.
FIG. 3A shows valve discs 24,26 in their closed position,
with no water flow through the valve disc, FIG. 3B.
As FIGS. 3A-3B to 13A-13B illustrate, the centroids 28 of
inlet openings 21,23 are shifted a few degrees toward the cold
water setting by handle 18, shown operably coupled in FIGS. lA,
lB to movable disc 26. In this way, hydraulic asymmetry is
achieved in the central positions of movable disc 26. For such
actuation, handle 18 is connected to control lever 19, mounted
on cartridge 22, which engages a recess 17 in movable disc 26.
Movable disc 26 is arranged to slide and pivot to control both
water flow and temperature through handle 18. Mixing chamber
27 opens only towards valve seat disc 24. As movable disc 26
is shifted over valve seat disc 24, mixing chamber 27 will
overlap hot and cold inlet openings 21,23 and outlet opening 25
in varying degrees by means of a control edge 29. Inlet opening
21 for hot water communicates by way of a connecting hot water
pipe 14 with flow heater 12. Movable disc 26 is provided with a
projection 30 having a thickened end 36 guided between parallel
ribs, not shown, on the inside wall of valve cartridge 22.
Owing to the hydraulic asymmetry, according to the
invention, when movable disc 26 is shifted to its central
positions by operating handle 18 and, hence, in the usual mixed
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3~
water temperature ranges bounding a so-called comfort zone, it
is ensured that the free flow section at inlet opening 23 for
cold water, shown in the embodiments of FIGS. 3A to 13A and
15A, with the special aid of control edge 29, is reduced when
compared to the hot water si~e. The free flow section for hot
water remains unaffected in the central positions.
Hydraulic asymmetry is accomplished by merely shifting
centroid 28 of the port areas of hot and cold inlet openings
21,23 in the fixed valve seat disc a few degrees towards the
cold water setting. This means that the inlet openings may be
identical to each other, as shown in FIGS. 3A to 13A.
Hydraulic asymmetry is also accomplished by simply making
inlet opening 21' for hot water larger in cross section than
inlet opening 23' for cold water, FIG. 14A. ~hus, hydraulic
asymmetry is achieved when handle 18 is in its central
position. Centroids 28' of hot and cold inlet openings 21',23'
need not be shifted toward the cold water setting.
In the example shown chain-dotted in FIG. 9A, both means to
achieve hydraulic asymmetry are adopted, that is, centroids 28
are shifted ~oward the cold water setting, and the port areas of
inlet openings 21,23 differ in size, the lengthwise extent of
inlet opening 21 for hot water being greater than that of inlet
opening 23 for cold water. Note that inlet opening 23 is
kidnèy-shaped and has its internal edge 32 drawn inward.
As previously mentioned, the embodiments represented and
described are merely examples of the embodiment of the
invention, and the latter is not limited thereto, rather, still
other possibilities are available within the scope of the
invention, especially regarding the special design and
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positions of the inlet openings. Thus,the centroid of the
port area of inlet opening 23 for cold water might alone
be shifted a few degrees of angle toward the cold water
setting.
The term "comfort zone" generally relates to the
range of mixed water temperatures from between about 35
and 45C. Also, within this comfort zone, a comparatively
wide swing of the operating lever should bring about only
a comparatively small variation in mixed water temperature.
Lastly, it is to be pointed out that a mixing valve,
according to the invention, where the hot water inlet is
largPr than the cold water inlet, may alternatively be
embodied as a two-handle valve, having two shut-off valves
for hot and cold water. Such shut-off valves may al50
have disc-like control elements, the inlet port of the
shut-off valve for hot water being larger than that of
the cold water shut-off valve.
