Note: Descriptions are shown in the official language in which they were submitted.
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LIMITING DEVICE FOR SINGLE CONTROL MIXING VALVE
TECHNICAL FIELD
The field of this invention relates to a cartridge for a single control mixing
valve, and more particularly to a device intended to normally limit the
maximum
flow rate of a mixing valve while allowing the user, when necessary, to exceed
this limited flow rate by an expeditious operation.
BACKGROUND OF THE INVENTION
The flow rate limiting devices of the type referred to here are sometimes
inserted into cartridges for single control mixing valves, either to avoid
wasting
water, to avoid uncontrolled spraying of water, or to avoid hammer knock which
may arise from a sudden and excessive opening or closing of the valve. Some
examples of limiting devices of this type are described in U.S. Patent
5,592,971.
Nevertheless, there is sometimes a need to override the limiting device
inserted in a cartridge. This need may arise, either because the user's
desires are
for increased flow rate, or because it is desired to use the same cartridge
model
both for installations in which limitation of the flow rate is required and
also for
2 0 installations in which this limitation is not required.
In the majority of known cartridges of the type in question, the limiting
device is inserted inside the cartridge. In these devises, disabling the
device is
not possible unless the cartridge is removable. The removal and re-
installation of
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the cartridge can not generally be performed by the casual user and poses
notable
difficulties even for a plumber.
In U.S. Patent 5,592,791, the limiting device includes a freely rotating
disc held in place by an elastic release ring. A top of the valve arm can be
removed without fully disassembling the mixing valve. This rotating disk has
the
function of limiting movement of the control stem to mixing positions giving
large quantities of water. The limitation can be overridden for further
movement
of the control lever to positions for full flow rate. To accomplish this
override,
the rotating disk is provided with projections, which yield elastically. An
l0 additional part is mounted on the control stem of the cartridge and this
part
engages with the operating handle mounted on the control stem. This additional
part works with the rotating disk to align it with the operating handle, and
possesses teeth which work with the elastically yielding projections on the
rotating disk to limit the stroke of the control stem while allowing greater
flow
positions to be reached when a greater force is applied to the operating
handle.
However, this limiting device cannot be removed or suppressed without complex
operation and without modifying the operating characteristics of the valve.
Furthermore, the flow rate-limiting device is quite large. A limiting device
of
this construction can not be applied to standard cartridges, either because
the
2 0 limited space available, or because of the shape of the external arm of
the control
stem, which cannot be modified. The control stem has to remain compatible with
the mounting of normal cartridges and operating handle components.
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What is desired is a limiting device for a mixing valve that can be
removed by an extremely easy, rapid operation which can be performed even by
an inexperienced person. Preferably, the limiting device can be replaced later
if
the need arises, while a mixing valve cartridge retains the size and external
form,
including both the cover and the control stem comparable to those of a
cartridge,
which has no limiting device. Furthermore, the cartridge can also be mounted
in
a normal valve and remain interchangeable with a normal cartridge that does
not
have a limiting device. In addition, any cancellation of the flow rate
limiting
function does not modify other characteristics of the valve.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention, a cartridge valve assembly
includes a stop limit device. The stop limit device includes a pivoted control
stem with an external arm rising from a support component. The support
component is provided with a projection adjacent to the stem on at least one
side
of the control stem. The control stem has its own external arm section with at
least one lateral projection intended to engage with the projection of the
support
component when the control stem is pivotably operated, so as to limit the
stroke
at a certain level of force of the control stem between two positions,
preferably a
2 0 shut-off position and a predetermined stop limit position the corresponds
to a
predetermined flow rate. The projection of the control stem, is on a component
that is removably seated to the external arm of the stem and positioned so as
not
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to modify the external structure of the control stem at a section intended to
mount
an operable handle.
The projection carried by the control stem can be selectively removed
from it when the stop limit device must be disabled. This disabling of the
stop
limit device is relatively easy due to the mounting of the removable
projection on
the external arm of the control stem. The cartridge need not be removed, nor
is it
necessary to take the cartridge out of the body of the valve in which it is
mounted.
Moreover, the presence of the projection or projections carned by the control
stem does not alter the external structure of the control stem in the area
intended
to receive an operating handle. The presence of the stop limit device does not
impose any modification to the cover of the cartridge, and thus, the cartridge
can
be produced in a form which is interchangeable with a normal cartridge which
does not incorporate a stop limit device, and can be used in a normal valve.
Preferably, a projection on the support component and a projection on the
control stem are present on opposite sides of the control stem. This
arrangement,
which gives a symmetrical structure, ensures balance of the forces in play,
which
avoids overloads and encourages proper functioning and durability for the
device.
If it is required for the user, to be able to exceed the limit of the maximum
flow rate delivered, which is imposed by the limiting device, at least one of
the
2 o projections on the support component and on the control stem is mounted
to_yield
elastically under a sufficiently strong force. In this way, when the user
exerts a
stronger than normal force on the operating handle of the valve, the co-
operating
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projections elastically yield and allow the control stem to reach positions
corresponding to delivery of a greater flow rate than the rate set by the stop
limit
device.
Preferably the elastic yielding is obtained by an elastic construction of the
projection itself, and preferably by the projection carried by the support
component. The projection can be made from a yieldable plastic. This ensures a
simple and economical construction for the device.
It is preferable that the projection on the control stem forms part of a plate
inserted in a corresponding cavity in the control lever and is capable of
being
l0 removed from it. Preferably this plate is seated in a section of the
external arm of
the control stem. The stem also can mount an external operating handle for the
valve. The mounted operating handle retains or locks the plate in the
corresponding seat of the control stem. When the handle is not mounted onto
the
stem, the plates can be easily unseated and removed from the control stem. In
this way, all that is required, in a very easy operation, is the removal of
the
operating handle of the valve from the control stem of the cartridge, to
access the
removable projections and take them off. Accidental removal of these
projections is normally prohibited by the presence of the mounted operating
handle of the valve.
While the projections have been described to provide a maximum flow
rate, the projections and their engaging teeth can be positioned near the shut
off
position to function as an anti-hammer device when the handle is moved toward
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the shut off position such that extra force is needed to completely shut off
the
faucet. In this fashion, the small delay of time required to exert extra force
eliminates hammer knock otherwise caused by excessively abrupt cessation of
water flow.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is now made to the accompanying drawings, in which:
Fig. 1 is a perspective, partially exploded and partially segmented view of
a faucet incorporating one embodiment of the invention;
Fig. 2 is a perspective view of a cartridge in accordance with one
embodiment of the invention shown in Figure 1;
Fig. 3 is an enlarged fragmentary view, the parts of it concerned with the
application of the invention; and
Fig. 4 is an exploded view of the parts shown in Figure 3, with the
addition of an operating handle, partially sectioned.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference now is made to Figure 1, which illustrates a faucet 30 having a
lower body 32, rotating spout 34, and cap 36 which house conventional valve
2 0 components (not shown) that may or may not be in cartridge format. The cap
has
an aperture 38 through with the control stem 5 extends through. With reference
now to Figure 2, a cartridge 40 for a single control mixing valve includes, as
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usual, a housing I intended to be introduced into a suitable chamber (not
shown)
within the conventional faucet 30. The housing 1 carnes a collar 2 intended to
sit
in the corresponding aperture 38 of a cap 36. The collar is applied so that it
can
be removed from the body and cap of the faucet that holds the cartridge
housing I
in place. The collar 2 of the cartridge has a support component 3 mounted so
that
it can rotate about a vertical axis (as oriented in the drawings). A pivot pin
4
extends via a transverse axis A-A, as shown in Figure 3, to mount control stem
5,
and allows stem 5 to pivot about axis A-A. The stem 5 possesses an external
arm
6, which extends from the support component 3 and which is intended to mount
an operable handle 16 for the valve, as shown in Figures 1 and 4. The stem
extends into the cartridge housing 1 in the opposite direction to form an
internal
arm 7, which drives the conventional internal mechanisms of the cartridge 40.
These latter parts are not described nor illustrated because they do no relate
to the
present invention. The parts so far described are themselves well known and,
in
the form shown, are characteristic of a standard type of cartridge for mixing
valves to which the present invention applies.
The stop limit device according to the invention more particularly
concerns the support component 3 of the control stem 5 and the control stem 5
itself, that is the parts shown in larger scale in Figure 3. Usually these
parts are
produced in plastic material. The support component 3 possesses two
projections
10 in the form of an arm ending in a distal, tooth I 1. The projections 10 are
positioned on opposite sides of the control stem 5. Because of the
characteristics
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of the plastic materials used for production of the support component 3, the
arm
has a limited resilient elasticity, so that normally it maintains tooth 11 in
a first
raised position, but is capable of bending slightly when a sufficient force is
applied to tooth 11, thus allowing it to flex a little from its normal
position. The
5 tooth 11 has a slight cant or ramp engaging surface 20 so as to promote
flexing at
the appropriate time.
The external arm 6 of the control stem 5 has a recess 9 (only visible on
one side in Figure 3) on opposite sides. A plate 12 is installed in each
recess 9.
The plate 12 occupies almost the whole recess 9 and is preferably held in
place by
1 o a friction fit or by a small snap fit undercut. The plate 12 extends
externally to
recess 9 to form a projection 13 which has a tooth 14 facing tooth 11 of arm
10 of
the support component 3. The tooth 14 also has a slightly canted surface 21.
The
flow rate-limiting device includes projections 10 and its teeth 11 of the
support
component 3 and projections 13 and its teeth 14 of the external arm 6 of the
control stem 5. The control stem 5 is shown in the shut off position. In order
to
open the valve, the stem 5 must be made to pivot about axis A-A in the
direction
of arrow F as shown in Figure 3. As the stem 5 pivots in the aforementioned
direction, the tooth 14 approaches tooth 11, and when the control stem has
reached a certain position the tooth surfaces 20 and 21 come into contact with
2 0 each other. The control stem 5 is then normally stopped in this position,
thus
limiting the flow output of the valve.
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However, if the need arises, the user can exert a stronger force than
normal on the control stem 5. Tooth then applies to tooth 11 on a force
sufficient
to make arm 10 elastically bend. Tooth 11 withdraws and allows tooth 14 to
move past it. The two canted surfaces 20 and 21 promote this action. The
control stem can then be taken to the positions corresponding to delivery of
greater flow rates. Naturally, the device is able to return to the shut off
position
because each tooth 1 l and 14 has greatly canted back surfaces 23 and 24 to
allow
ease in overriding during motion back to the shut off position. The
projections 10
and 13 then regain their normal configuration when the control stem is again
1 o moved to the position below the maximum flow rate set by the stop limiting
device.
Note that both the projections 10 on the support component, and the
projections 13 on the control stem 5 are positioned in spaces which are
normally
not used under the handle 16 so that the presence of the projections are not
an
obstacle nor do they involve an increase in the size of the cartridge or a
remolding
of handle 16.
In order to disable the stop limit device, it only requires removal of the
plates 12 from the corresponding recess 9 of the external arm 6 of the control
stem 5. To facilitate this operation, each plate 12 can offer an access slot 1
S,
2 o which allows insertion of any piece of equipment to remove the plate. The
stop
limit device can be easily re-mounted by a mere insertion of the plates 12
again in
their respective recesses 9. When the stop limit device is disabled by removal
of
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the plates 12, the projections 10 shown on support components remain present
although inactive. Their presence during this disablement involves no
disturbance to operation or any obstacle.
It is advantageous that the plates 12 extend in part into the area of external
arm 6 of the control stem 5, on which is seated a part of the operating handle
16
which is usually connected to the control stem. An example of this arrangement
is shown in Figure 4. The operating handle, in this case, is in the shape of a
lever
with a handle 16 and a connecting hub 17. The hub 17 has one cavity 18, which
is mounted, onto the section of the external arm 6 of the control stem 5. The
hub
17 fixes the handle 16 by means of a screw 19, which is screwed down, into a
tapped hole 8 on the control stem. When the hub 17 is mounted onto arm 6 of
the
control stem, the hub 17 retains the plates 12 firmly in the recesses 9 and
prevents
them from coming out accidentally. One merely removes the operating handle 16
by unscrewing the screw 19 to gain access to the recess 19. The plates 12 may
be
removed from or installed into position within recess 19 without disturbance
to
the cartridge or cover 1 or collar 2. This simple operation can be carried out
very
easily by any plumber or even by the casual user.
In the illustrated embodiment, the user can exceed the limit imposed by
the stop limit device for the maximum flow rate which can normally be
delivered
2 o by rendering a sufficient force to flex the arm 10 and let teeth 11 and 14
disengage from each other. However, the construction may be easily modified to
prevent any override of the stop limit device. Firstly, projection 10 of the
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support component 3 can be structurally rigid form, so that contact between
teeth
1 l and 14 limits the turning stroke of the control lever without any
possibility of
exceeding the limit. Alternatively, the teeth 11 and 14 may have their
respective
surfaces 20 and 21 positioned at complementary negative cambers such that they
interlock or hook in one direction to prevent further motion in the full flow
direction F.
A particular advantage of the invention lies in the fact that any elimination
of the flow rate limiting function does not alter any other characteristic of
the
cartridge and the valve. Movement of the control stem toward positions of
mixing for greater quantities of hot water remains completely independent of
the
flow rate-limiting device and therefore do not show the effects of any
elimination
of the latter or its replacement. Furthermore, the flow rate-limiting device
does
not affect the use of a temperature-limiting device.
It must be understood that the invention is not limited to the form of
realization described and illustrated as an example. Several examples are
within
the capacity of a person skilled in this field; for example, the invention may
be
applied to different types of cartridge from the standard one shown or to
different
type of non-cartridge mixing valves installed in faucet 34. Also the limiting
device, shown installed on opposite sides of the control stem, can also be
supplied on only one side of the stem. The form of the co-operating
projections
of the support component and the control stem can be chosen in various ways.
The projections of the support component, described as made in one integral
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piece, can instead be affixed to the support component and if necessary can be
made up in a different material, for example, metal. The projections can be
removably mounted to the control stem in a different way from the insertion of
plates in recesses. For example, the projections can be distal extremities of
a
pivot pin, possibly profiled, crossing a hole drilled through the external arm
of
the control stem. There can also be various ways of facilitating removal of
the
projections from the control stem. If certain projections must be capable of
resiliently yielding elastically, this resilient elastic property can be
attributed to
the projections on the control stem as well as those on the support component,
or
1 o to all projections.
These and other modifications and any substitution with equivalent
techniques can be carried out as described and illustrated, without in any way
going outside the sphere of the invention and the range rate of this patent.
