LIMITING DEVICE FOR SINGLE CONTROL MIXING VALVE

Abstract: A cartridge (40) for a single handle mixing valve (34) includes a stop limit device for limiting the normal motion of a single handle (16). The stop limit device includes a pivotable control stem (5) and a support component (3). The support component (3) has an external arm (10) with teeth (11) that are yieldable under sufficient force. The control stem (5) has projections (13) mounted within recess (9) in the item. The projections (13) also have teeth (14), which engage teeth (11) to limit motion of the stem (5).

Description: 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 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 FP3022Masco 2 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 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 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. FP3022Masco 3 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 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 FP3022Masco 4 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 carried 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 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 FP3022Masco 5 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 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 FP3022Masco 6 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 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 FP3022Masco 7 usual, a housing 1 intended to be introduced into a suitable chamber (not shown) within the conventional faucet 30. The housing 1 carries 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 1 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 11. The projections 10 are positioned on opposite sides of the control stem 5. Because of the characteristics FP3022Masco 8 of the plastic materials used for production of the support component 3, the arm 10 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 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 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 each other. The control stem 5 is then normally stopped in this position, thus limiting the flow output of the valve. FP3022Masco 9 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 11 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 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 15, 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 FP3022 asco 10 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 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 FP3022Masco H support component 3 can be structurally rigid form, so that contact between teeth 11 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 FP3022Masco 12 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 resiliency 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 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.

Claims: FP3022 asco 13 CLAIMS I claim 1. A cartridge valve assembly for single handle control mixing valve, including a device for limiting the normal motion of single handle along a first direction and including a pivotable control stem in a support component and having an external arm section rising from the said support component, said cartridge valve assembly characterized by: said support component having on at least one side of the control stem a projection adjacent to the stem, the external arm section of the control stem having at least one lateral projection to engage with said projection on the support component when the control stem is pivotally moved about its own pivot axis so as to limit the range of movement of the control stem corresponding to a certain force level and the projection of the control stem forming part of a component removably seated to the external arm of the stem such that it does not hinder control stem from mounting an operating handle. 2. A cartridge valve assembly as in claim 1, further characterized by: the support component having a lateral projection on opposing sides of the control stem and the control stem having a projection on opposing sides thereof. FP3022Masco 14 3. A cartridge valve assembly as defined in claim 1, further characterized by: at least one of the said projections on the support component and the control stem being mounted in such a way as to be able to yield elastically under a sufficient force. 4. A cartridge valve assembly as defined in claim 3, further characterized by: at least one projection being constructed to be slightly elastic. 5. A cartridge valve assembly, as defined in claim 4, further characterized by: the projection carried by the support component having a slightly elastic construction. 6. A cartridge valve assembly as defined in claim 3, further characterized by: said projections being positioned to limit normal handle motion between a shut off position and a normal full flow position and said sufficient force enabling said handle to move to a position exceeding said normal full flow position defined by the projections. FP3022Masco 15 7. A cartridge valve assembly as defined in claim 1, further characterized by: said at least one lateral projection on the control stem forms part of a plate removably seated in a corresponding cavity of the control stem. 8. A cartridge valve assembly, as defined in claim 7, further characterized by: said plate being removably seated in the external arm section of the control stem which is received by an external operating handle that maintains said plate seated in its corresponding position in the control stem, and allows its removal prior to mounting of the operating handle onto the control stem. 9. A cartridge valve assembly as defined in claim 7 further characterized by: said projection on the control stem having a first tooth depending therefrom; said projection on said support component having a complementary tooth upwardly extending to be engageable with said first tooth or said control stem; one of said first tooth and complementary tooth having a canted surface to allow one tooth to act as a ramp for the other tooth; one of said first tooth and complementary tooth being elastically yieldable under a sufficient force to allow one tooth to ride over said other tooth. FP3022Masco 16 10. A cartridge valve assembly as defined in claim 1 further characterized by: said projection positioned to limit normal handle motion between a shut off position and a normal full flow position. 11. A removable flow limiting device for a single handle control mixing valve; said device characterized by: a first projection seated onto the side of a control stem and extending therefrom; a second projection seated adjacent to the stem; said first and second projection engage together when said control stem is pivotally moved about its pivot axis so as to limit movement of the control stem to a stop position at a certain force level. 12. A removable flow limiting device as defined in claim 11 further characterized by: at least one of said first and second projections being resiliently yieldable under a sufficient force and said projection engage each other to override one another when said sufficient force is exerted. FP3022Masco 17 13. A cartridge valve assembly as defined in claim 11 further characterized by: said projections being positioned to limit normal handle motion between a shut off position and a normal full flow position and said sufficient force enabling said handle to move to a position exceeding said normal full flow position defined by the projections. 14. A cartridge valve assembly as defined in claim 13 further characterized by: said projection on the control stem having a first tooth depending therefrom; said projection on said support component having a complementary tooth upwardly extending to be engageable with said first tooth or said control stem; one of said first tooth and complementary tooth having a canted surface to allow one tooth to act as a ramp for the other tooth; one of said first tooth and complementary tooth being elastically yieldable under a sufficient force to allow one tooth to ride over said other tooth.

Inventors: KNAPP FRANCESCO, KNAPP, FRANCESCO
Applicants: KNAPP FRANCESCO, MASCO CORP, KNAPP, FRANCESCO, MASCO CORPORATION
Application year: 1999
Main classification: F16K35
IPC codes: F16K11, F16K31, F16K35, F16K51