Note: Descriptions are shown in the official language in which they were submitted.
A MIXING VALVE WITH VALVE PLATES
PROVIDED WITH AN ATTACHMENT MECHANISM FOR
THE ~IXED PLATE TO PRO~IDE A COMPRESSIVE FORCE
Technical Field
The present invention deals with a mixing valve
consisting of a faucet body, a cartridge assembly inserted
within the faucet body, a control mechanism, a support
seat for fixing a valve plate of hard material thereto,
a seal placed between the fixed valve plate and the
support seat, and a movable valve plate connected to the
control mechanism for relative sliding movement with the
fixed valve plate so as to regulate the flow rate and the
mixing proportions.
Backqround of the Invention
In order to achieve an effective closing, a fixed
valve element commonly referred to as a fixed valve plate,
and a movable valve plate of the mixing valve must be
pressed against each other with a compressive force
greater than the force exerted by the pressure of the
flowing water because, otherwise, the water pressure would
separate the movable valve plate from the fixed valve
element preventing them to be closed, and similarly a
compressive force must be applied between the fixed valve
plate and its own support surface so as to compress a seal
therebetween either to assure proper function of the seal
or to prevent an ejection of the seal itself or its
deformation in case excessive pressures should occur.
In most cases, the minimum compressive force
necessary to compress the seal and to hold it tightly in
its correct position is much higher than the minimum
compressive force necessary to keep the fixed valve plate
and the movable valve plate in operative contact. In
known cartridge valve structures, the fixed valve plate is
simply resting ~n a support seat in a bottom portion of a
replaceable cartridge inside the faucet body and a
compressive force is exerted between the movable valve
6~432-45
plate and support seat which pushes the support seat to~ard the
movable valve plate or vice versa~
As a consequence, the exerted compressive force must be
at least equal to or greater than the higher one of the two
minimum compressive rorces needed for the specified purposes. In
other words, the applied compressive force is equal to the
compressive force necessary to compress the seal and hold it
tightly in its correct position. The compressive force is thus
unnecessarily high for the purpose of keeping the movable valve
plate in contact with the fixed valve plate. Because oE such
excessively high force applied between the movable plate and fixed
plate, the faucet is harder to operate and needless mechanical
stresses of the parts are introduced. A cartridge valve in which
its bottom portion is hydraulically biased to produce a
compressive force between the fixed valve plate and movable valve
plate are particularly disadvantaged by the above mentioned
excessively high compressive forces.
Summary of the Invention
This invention relates to a mixing valve comprising
a Eaucet body having a cartridge receiving chamber;
a cartridge housed in said car-tridge receiving chamber
and having a fluid receiving chamber and a support surface Eacing
the fluid receiving chamber;
a valve plate fixedly mounted on the support surface;
a seal means interposed between the fixed plate and the
support surface;
a movable valve plate in contact against said fixed
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valve plate and operably connected to a control means Eor moving
said valve plate relative to said fixed valve plate:
compressive means Eor pressing the fixed valve plate
against said support surface thereby compressing the seal means
interposed between the fixed plate and said support surEace
independent of any smaller compressive Eorces exerted between said
fixed plate and said movable plate.
In accerdance with the invention, a mixing valve is
constructed such that a compressive force greater than the
compressive force between the fixed valve element and movable
valve plate can be exerted onto the seal placed between the fixed
valve element and its own support seat. The construction is
achieved, according to the invention, with a certain attachment
mechanism which connects the fixed valve element to its own
support seat with the seal compressed between them and by keeping
these parts under a compressive force.
Due to this construction, the compression of the seal
beneath the fixed valve element is determined by the elastic and
geometrical characteristics oE the seal itself, the attachment
mechanism and the connected parts. The compressivé force is
continuously applied on the attachment mechanism, the fixed valve
element, its support seat, and the seals, independent of the
forces applied
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from outside onto the fixed valve element and onto the
support element.
Any external applied compressive forces can then have
its magnitude determined exclusively to produce the
necessary operating sealing contact between the fixed
valve element and the movable valve plate. The
compressive force between the fixed valve element and
movable valve plate can be chosen by considering only the
needs of contact between the fixed valve element and
movable plate and without considering the fixing and
compression of the seal under the fixed valve element.
The compressive force exerted between the plates can
be either produced by an elastic element such as a spring
or can be produced by exertion of water pressure on a
bottom portion of the support seat which acts as a piston
to push the fixed plate against the movable plate. The
compressive force exerted between the plates can be
greatly reduced thus obtaining a most easily operated
mixing valve faucet free from the excessive frictional
forces commonly existing between the plates.
Brief Description of the Drawings
Reference is now made to the accompanying drawings in
which:
Fig. 1 shows the side sectional view of a mixing
valve including a cartridge according to the first
embodiment of the invention;
Figs. 2 through 4 similarly show side sectional views
of the bottom cover assembly for a faucet cartridge
including the fixed valve plate and its attachment
mechanism in accordance with some alternate embodiments of
the invention.
Detailed Description of the Preferred Embodiment
The faucet shown in Fig. 1 includes a body 1 that has
two inlet pipes 7 and 8 connected thereto for the passage
of hot and cold water. The body 1 has an internal chamber
2 that houses a cartridge and forms an annular periphery
2a communicating with an outlet port 2b. On the opposite
side to the pipes 7 and 8, the chamber 2 is closed by a
lid 5 threadedly connected to body 1. A seal 6 is
interposed to prevent leakage.
The cartridge consists of a lower member 10 which is
preferably made from plastic and is capable of axial
motion in the chamber 2 of the faucet body 1. The lower
member 10 has a bottom section 9 which has two depending
male connections 11 and 12 provided with seals llb and 12b
which get sealed into female seats 3 and 4 provided in the
faucet body 1. Seats 3 and 4 have openings 3a and 4a
therethrough. The bottom section 9 of the cover 10 has
passages lla and 12a through the respective connections 11
and 12 in communication with openings 3a and 4a and extend
upward through a surface 9a that forms a support seat for
a fixed valve plate 1~3 of the faucet.
The passages lla and 12a are surrounded by the seals
16 and 17. In the present embodiment, the seals 16 and 17
comprise two separate annular pieces housed in
corresponding annular grooves recessed in the bottom
section 9 of the cover 10.
The seals 16 and 17, however, can be replaced by a
single piece having a more complex form. The seals 16 and
17 function to seal between the support surface 9a and the
fixed plate 18. The plate 18 has two openings 18a and 18b
aligned with the passages lla and 12a for the passage of
hot and cold water.
A movable valve plate 19 abuts the flxed valve pla~e
18 and is attached to a control mechanism ~o move the
valve plate 19. In particular, the movable valve plate 19
is affixed to a control slide 20 surrounded by a control
ring 21 which is rotatably mounted in the cover 10. The
slide 20 abuts on the opposite side from the plate 19
against a half bearing 22 fixed in the opening of the
cover 10. The half bearing 22 abuts against the lid
which closes the faucet body 2. Another half bearing 23
is housed in the lid 5. An articulation ball 25 with a
seal 24 is interposed between the half bearings 22 and 23.
An arm ~6 extends outwardly from the ball 25. A cap
28 with an operating lever 29 is connected to the arm 26.
A flat key 27 downwardly depends from ball 25 which is
received in a corresponding seat of the control slide 20.
The control mechanism, by various rotating and tilting of
the lever 29, shifts the control slide 20 and the movable
plate l9 mounted thereto, both in translation and
rotation, relative to the fixed plate 18 so as to
regulate, as desired, ~luid flo~ from the pipes 7 and 8
which mix in the annular chamber periphery 2a where the
mixed flow then exits outlet 2b.
In the space between the bottom section 9 of the
cartridge cover 10 and the bottom of the faucet body 1, a
spring 30 is positioned consisting of a disk bored for the
passage of the connections ll and 12 and arched so as to
provide a repulsive force between the bottom of the body 1
and the bottom section 9 of the cartridge cover lO. Other
spring constructions are possible such as elastomeric
rings placed beneath the connections 11 and 12 or between
the bottom 9 and body 1.
The fixed valve plate 18 is not simply resting on the
support element consisting of the bottom 9 of the
cartridge cover 10 as is known in the prior art, but it is
secured to it by an attachment mechanism placed in such a
way as to keep the seals 16 and 17 under compression.
Particularly, in the form represented in Fig. 1, the
fixed plate 18 has a recessed central seat constructed to
receive a screw head 31 whose threaded stem is screwed
into the bottom 9 of the cartridge cover lo. The
different parts are sized in such a way that, when the
screw 31 is screwed down and keeps the fixed plate 18
positively in contact with the bottom 9. The seals 16 and
17 are compressed from a compressive force adequate to
guarantee the sealing between the bottom 9 and the fixed
plate 18 and to maintain the seals 16 and 17 in their
seats against every action tending to eject them or deform
them. This compressive force, which can also be high, s
kept between the parts 9, 16, 17, 18, 31 without
influencing the other faucet components.
Independently of the water pressure, the spring 30
applies a force onto the bottom of the cartridge co~er 10
directed toward the lid 5. This force is transmitted from
the bottom section 9 of the cover 10 to the fixed plate 18
and from the latter to the movable plate 19, to the slide
20, to the half bearing 22 and to the lid 5. This force
keeps the cartridge bottom 10 in contact with the fixed
plate 18 (through the seals 16 and 17 which result to be
compressed by this force) and the plates 18 and 19 in
contact with each other as well, pxoviding them with a
sealing contact~ This force must be sufficient to
guarantee a regular working of the faucet at low
pressures.
The elastic spring 30, working between the faucet
~ody and the cartridge, can be constructed so as to supply
the minimum necessary compressive force for sealing
contact between the plates 18 and l9. In many instances,
spring 30 can be eliminated.
The water pressure, fed by the pipes 7 and 8, works
on the connections ll and 12 like they were pistons, by
pushing them toward the plates 18 and 19 and through an
opportune sizing of the different parts, it produces a
force which transmits itself, like the one already
considered, as far as the lid 5 and which increases the
compressive force be-tween the plates 18 and l9 for the
effective working pressure by guaranteeing a correct
behavior.
As the compressive force applied on the seals 16 and
17 does not affect any other faucet parts it therefore can
be chosen higher than usual. Thus a higher freedom is
afforded in planning these seals which can have a larger
section or a more resilient force than those usually
accepted for necessity. The screw 31 allows, if
necessary, disassembly of the fixed plate off the
cartridge but, in most cases, i' is not required thz' such
disassembly be carrie~ out. Because the seals 16 and 17
are compressed independently of spring 30, the spring 30
no longer needs to supply the relatively high compressive
force which is enough to compress the seals 16 and 17 and
is widely excessive, in most cases, for the sealing
contact between the plates 18 and 19 whose adhesion
therefore occurs under an unnecessarily high pressure.
This disadvantage of the previous valves is thereby
eliminated.
Referring to Fig. 2, the fixed plate 18 with its
central seat 15 can be held by a protuberance 13
integrally formed with the cartridge bottom 9 and can be
hot pressed or pressed by using ultrasounds so as to form
an enlarged head 13a while, during such operation, the
plate 18 is being forced downwardly against the bottom 9
by a punch which supplies the necessary force to the
compression of the seals 16 and 17 during assembly. The
enlarged head 13a retains the plate 18 and provides the
compressive force transmitted to seals 16 and 17.
Even other arrangements can be foreseen to cooperate
with the central seat 15 of the fixed plate 18, for
instance rivets, bent elements, strong elastic release
teeth, and so on.
In Fig. 3 the fixed plate 18c can also be held
against the bottom 9 of the cartridge cover by compressing
the seals 16 and 17 and by notching the periphery of the
plate and not in its center as it occurs in the previous
valve forms. The plate 18c, according to Fig. 3, has a
peripheral lowered seat 14 where some projections 32 of
the cartridge cover 10 are engaged and provide the
compressive force on seals 16 and 17. ~he projections 32
can consist of strong elastic release teeth or can be
portions of the cover deformed by heat or by ultrasounds
or in some other way, while the plate 18c, during such
operation, is being pushed by a punch so as to compress
the seals.
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As shown in Fig. 4, the retention of the fixed plate
18c against the bottom 9 about its periphery can also be
realized through an additional tool, like a ring 33
introduced into the lowered seat 14 of the disk and made
integral to the cartridge cover 10. The ring can be made
of plastics and can be fixed to the cover 10 through
soldering or gluing or it can consist of an elastic ring
which fixes itself through expansion (in this case it can
be metallic). The fixed plate 18c could also be retained
again~t the bottom 9 by a combination of eithsr peripheral
or central located attachments i.e. by combining an
embodiment like those shown in Figs. 3 and 4 with an
embodiment like those in Figs~ 1 and 2.
The seals llb and 12b interposed between the support
element and the body bottom, are desired to not cause
higher axial thrust than the minimum compress-ve force
required for the sealing contact between the plates.
Radial seals llb and 12b like the ones shown in Fig. 1,
seals exerting only a moderate axial thrust or more
complex seals whose axial thrust (or part of it), is
somehow compensated without the thrust beiny transferred
between the faucet plates.
Of course, different modifications, in addition to
those already mentioned, can be used. For example, the
fixing of the plate 18 could be made through two screws
(like 31) placed along a diameter of the disk or through
three screws placed like a triangle and so on.
Variations and modifications of the present invention
are possible without departing from the scope and spirit
as defined in the appended claims.
