GB1562917A - Diaphragm valve - Google Patents

Description

(54) DIAPHRAGM VALVE (71) We, ELKAY MANUFACrURING COM- PANT, a corporation of the State of Illinois, United States of America, of 2700 South 17th Avenue, Broadview, Illinois 60153, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to valves, and more particularly to cam operated diaphragm valves for use in water faucets.

Heretofore, while diaphragm valves have been widely used in fluid flow lines for controlling flow or as shut-off valves, such valves have not come into widespread use in faucet valves for water systems.

Diaphragm valves have not been generally considered for faucet valves, because of the relatively severe requirements.

Certain of these requirements relate to sealing characteristics specific to faucet valves. Additional requirements involve structural considerations unique to diaphragms wherein elastomeric materials are employed. Finally, the effect of the working environment, water in the case of faucet valves, on elastomeric diaphragm materials imposes special requirements.

The seealing characteristics required for faucet valves can be summarized briefly.

Faucet valves should open and close cleanly and gradually without requiring excessive manual force. The mechanism should produce and maintain a seal at the valve seat over a large number of operating cycles and over a long period of time. When elastomeric materials are employed for the member engaging the valve seat, as in the case of diaphragm valves, the elastomeric material is desirably soft and pliable to conform to the seat even where the seat is irregular due to mineral build-up or dirt, or erosion of the seat. To avoid abrading and wearing the elastomeric material, it is desirable to have no relative motion between the elastomeric material of the diaphragm and the seat.It is also desirable to utilize fluid pressure to enhance the seal at the seat so as to minimize the stresses imposed on the elastomeric material by outside actuating member and avoid or reduce permanent set of the material.

While to obtain such desirable sealing characteristics suggests the use of elastomeric materials which are soft and pliable, structural considerations suggest the- use of materials which are hard and stiff and have the strength of structural members to withstand the stresses imposed by the valve actuating members on the sealing portions of the diaphragm as the valve actuating member forces the diaphragm against the valve seat, and on the supporting section of the diaphragm as the supporting section is flexed during the stroke of the valve actuating member. Moreover, different sections of the diaphragm are desirably hard and stiff to withstand mechanical and fluid pressures prevailing within the valve structures which tend to extrude and stretch the diaphragm out of shape or position.

Finally, the chemical action of water on elastomeric material tends to. deteriorate the material. Desirably the characteristics of hardness, elongation and tensile strength should remain constant over the useful life of the diaphragm. This means that not all elastomeric materials may be used ia faucet valves, only those capable of withstanding the chemical effect of water.

According to the present invention there is provided a faucet valve assembly,. including a valve body having upper and lower sections, said lower section having a chamber with an outlet passage for water, and an inlet for water extending into said chamber, the end of said inlet providing. an annular valve seat, a movable. valve plunger nonrotatably and slidably supported within the upper section of said valve body for recip rocal movement along the axis of said valve seat between valve open and valve closed positions, said valve plunger having a recess in one end portion said recess being concentric with and having a larger inside diameter than the inside diameter of said valve seat, and a diaphragm of elastomeric material extending across said chamber and gripped at its outer edge by said valve body to seal and provide one end of the chamber, said diaphragm having an upwardly projecting valve closure portion received in the valve plunger recess with a downward facing surface engaging the valve seat in the valve closed position of the plunger, said closure portion of the diaphragm extending longitudinally beyond said end of the valve plunger and said valve plunger having a valve closed position wherein said downward facing surface engages and is pressed against said valve seat to provide a primary seal and to cause the closure portion to overhang the inside lip of the valve seat, said diaphragm further having a convoluted supporting section extending radially from said closure portion which rolls during the stroke of the valve plunger, the open valve position of the valve plunger providing clearance between the valve seat and said surface of the valve closure portion to admit water from the inlet which flows radially across the valve seat into the chamber and out the outlet passage, said plunger having an end wall extending outwardly from said end portion against which the supporting section of said diaphragm is pressed by water pressure in the valve open position of said plunger, the combination of said end portion and end wall of the plunger, and the side wall of said chamber, in the valve open position of the valve plunger, providing a continuous surface at least equal in radial extent to the supporting section of the diaphragm and rigidly backing up the supporting section in the valve open position of the valve plunger and holding said supporting section against stretching under the pressure of water in the chamber The invention will now be described by way of example only with particular reference to the accompanying drawings wherein:: Figure 1 is an elevational view with portions broken away and shown in section of a replaceable valve cartridge for faucets incorporating a diaphragm valve assembly of the present invention; Figure 2 is a sectional view of the replaceable cartridge shown in Figure 1; Figure 3 is a plan view of the cartridge shown in Figure 1 from the stem end; Figure 4 is a fragmentary elevational view of the cartridge shown in Figure 2 looking in the direction indicated by the arrows designated 4A in Figure 1; Figure 5 is a horizontal sectional view taken in the plane of lines 5-5 in Figure 2; Figure 6 is a horizontal sectional view taken in the plane of line 66 in Figure 2; Figure 7 is a perspective view of the diaphragm component of the cartridge, shown separately and out of the valve assembly.

Fig. 8 is a sectional view with portions shown in elevation of a mixing valve assembly embodying the invention; Fig. 9 is a plan view of the mixing valve assembly of Fig. 8; Fig. 10 is a view of the lower face of the rotary cam, taken in the direction of lines 11W10 in Fig. 8; Fig. 11 is a plan view of the hot water plunger, taken in the direction of line 11 in Fig. 8; and Fig. 12 is a plan view of the cold water plunger taken in the direction of line 12 in Fig. 8.

Referring specifically to Figs. 1 and 2 of the drawings, a replaceable valve cartridge incorporating the diaphragm valve assembly constructed in accordance with the invention is illustrated. Broadly stated, the valve cartridge includes a generally cylindrically shaped body or housing 10, an operating stem 12 having a knurled portion 14 to which a handle may be attached separated by an annular flange 15 from a smooth portion 16 of the stem. The lower section 17 of the cartridge body 10 is provided with an inlet port 18 and oppositely disposed side outlet ports 19 leading from an outlet chamber 20.

In keeping with the invention, the replaceable cartridge utilizes a diaphragm valve including a diaphragm 22, a reciprocable valve plunger 24 and a tubular inlet member 26 for water, the end of said tubular inlet member 26 serving as a valve seat 27. The valve plunger 24 is cammed downward from valve open to valve closed position by a cam plate 30 carried by the stem 12. When the stem is turned to the closed position, the cam plate 30 produces a camming force that acts to force the plunger 24 downward against the force tending to raise the diaphragm and open the valve due to the inlet water pressure acting on the diaphragm.

That force due to water pressure is utilized to raise the valve plunger 24 to valve open position when the stem is turned to the open position. The valve plunger 24 is supported for reciprocal movement along the axis of the tubular inlet in its stroke between valve open and valve closed positions, by means herein shown in Fig. 6 as projecting vertical straight keys 32 on the exterior of the valve plunger 24 received with a sliding fit in keyways 34 in the cylindrical inside wall of the upper section 36 of the body of the valve cartridge. By restraining the plunger 24 so that it cannot rotate, there is no relative movement between the valve plunger and the diaphragm 22, which tends to wear out the diaphragm and shorten its life.The upper section of the body 36 has a cylindrical inside wall 37, and the valve plunger 24 is cylindrical in outer configuration and is slidably received within the inside wail 37 of the upper section of the body. The cam plate 30 similarly is cylindrical in shape and has a helical or inclined lower cam surface 28 engaging a similarly helical or inclined upper cam surface 38 on the plunger, the cam surfaces on the cam plate and plunger cooperating to reciprocate the plunger 24 upon rotation of the stem 12. The stem is permitted about 150 of rotation as defined by the arcuate recess 39 (Fig. 5).

The body 10 of the replaceable valve cartridge has a generally cylindrically shaped outer surface and is formed of the two injection molded plastic sections 17, 36. The cartridge is sized to fit in a like sized cylindrical bore in the faucet assembly and has external O-rings 40 in recesses in the outer surfaces of the cartridge for sealing purposes and a pair of ears 42 on the stem end of the body located to fit in correspondingly shaped recesses in the faucet assembly to hold the cartridge against rotation. The upper section 36 and lower section 17 of the cartridge body 10 are telescopingly arranged with the outer bead 44 on the diaphragm of the diaphragm valve assembly clamped between the sections.To assemble the sections, they are slid into telescoping relation and tabs 46 (Figs. 1, 6) are provided on the outside of the upper section 36 which are received in snap holes 48 in the wall of the lower section 17 of the valve body, the plastic parts having sufficient resilience to allow the sections to be forced together and the tabs 46 to snap into the holes 48 to lock the upper and lower sections against both endwise separation and relative rotational movement.

As shown more particularly in Fig. 2, the stem 12 carries the cam plate 30 and these elements are held within the upper section 36 of the valve body against axial movement out of the body by the engagement of the top of the cam plate 30 at its outer edge with a shoulder 50 provided by the upper section 36 of the valve body.

For preventing both downward and lateral tilting movement of the stem 12, the supper section 36 of the valve body is provided with four outwardly resilient fingers 52, as shown in Figs. 1-3 which are molded to present an inside bearing diameter slightly smaller than the outside diameter of the smooth portion 16 of the stem 12. In assembly of the stem 12 within the upper section 36 of the valve - body, the stem is inserted from the bottom and the annular flange 15 spreads the fingers 52 which snap back and press against the smooth portion 16 of the stem 12. The underside of the flange 15 seats on flat top edges 54 of the fingers 52. The stem 12 and cam plate 30 are thus held by the shoulder 50 and fingers 52 against end play, and the fingers act to take up all clearance and hold the stem 12 against side play or tilting.

Turning now to the valve assembly in more detail, the upper section 36 of the valve body 10 provides a cylindrical internal chamber 56 in which the cam plate 30 and valve plunger 24 are received. The lower section 17 of the valve body provides a tubular inlet 26 for water, the end of the tubular inlet serving as a valve seat 27.

Around the tubular inlet 26 and between the same and an inside wall 58 of the lower section of the valve body there is provided an annular outlet chamber 20 and outlet passages 19, shown in Fig. 1, for water flow from the outlet chamber through the faucet.

The diaphragm 22 of elastomeric material is gripped by the bead 44 at its outer edge between the telescoping valve sections 17, 36 and provides a fluid seal between the outlet chamber 20 and the plunger 24 and cylinder 56 supporting the plunger, such that the plunger, cam plate 30 and stem 12 are dry. The invention thus provides a dry stem valve without the problems of corrosion due to water being present or leading into the actuating parts of the valve assembly.

One of the important considerations in the development of this invention has been the selection of a suitable material for the diaphragm 22. It has been found that the material should be one: (1) that is not attacked by the constituents in water and ages well; i.e. does not crack or split with age; (2) that has long life without drastic change in its properties of hardness, elongation and strength over many cycles of compression and flexing, and does not take an excessive set when squeezed or compressed for long periods between operating cycles or after many cycles of operation; (3) that has a sufficiently high fatigue limit so that the stresses imposed on the material in a cycle of operation are significantly less than the fatigue limit;; (4) that has a surface when molded which withstands the erosive effect over long periods of use of the passage of hard particles in water flowing over the material, such as sand, and the abrasive action due to build up on the valve seat providing a rough edge which tends to bite into and abrade the rubber upon engagement and disengagement with the valve seat itself.

While other materials may be found suitable for the diaphragm 22, EPDM rubber with a hardness range of about 60 durometer has been found satisfactory, and the diaphragm 22 is preferably moulded of such material in a configuration providing an inverted dished valve closure portion 5 (Fig. 7) with a rim 60 which is pressed against the valve seat 27 in the valve closed position of the plunger as shown in Fig. 2, and which has clearance with the valve seat 27 in the valve open position of the plunger, as shown in Fig. 1, to admit water from the inlet 18 to the outlet chamber 20.

The inverted dished valve closure portion 59 of the diaphragm 22 is received in a recess 62 in the valve plunger 24 such that the rim 60 of the valve closure portion extends beyond the end of the plunger 24 to engage the valve seat. In the valve closed position, shown in Fig. 2, the rim 60 of the valve closure portion is pressed against the valve seat and the side wall 64 of the closure portion is squeezed slightly to provide a primary seal at the valve seat The squeezing of the rubber also causes the inside edge of the rim 60 of the closure portion to flow over the inside lip of the valve seat 27, and penetrate into the mouth of the tubular inlet 26 to provide a secondary seal.It has been found that to obtain a clean gradual opening at the valve seat when the plunger is raised from the valve closed position, the rubber should not be squeezed more than about .020" from its original thickness with a helical cam surface as shown, otherwise too great angular rotation of the handle and stem 12 is required to raise the rim 60 of the valve closure clear of the valve seat 27 to admit fluid flow. With excessive squeeze, the valve closure rim also acts like a reed as water flow begins, producing noise, and the valve closure tends to pipe open so that a surge of water from the inlet to the outlet is produced.All of these effects are unacceptable in a faucet valve in which a good clean gradual opening of the valve is desired under widely varying pressure conditions as may be encountered in water systems where the pressure can be expected to vary between well pump systems in rural communities to high pressure city water systems. Furthermore, it has also been found that applying compression stresses to elastomeric material of the types normally used for diaphragms in excess of 15% of the total thickness in the zone of compression causes high stresses and induces an excessive compression set in the material.

With excessive compression set in the valve closure, as the seat erodes and wears away during extended use, initially obtained good seal and gradual opening characteristics will deteriorate.

Accordingly, in the preferred form of the diaphragm construction embodying the invention, the sidewall 64 and rim 60 of the valve closure portion are dimensioned wider than the valve seat and the sidewall has a height such that with a squeeze of approximately .020" at the rim, the sidewall 64 of the valve closure portion is longitudinally compressed substantially less than 15% of the height "A" of said sidewall portion, to avoid overstressing the resilient material and inducing excessive compression set, and producing a primary seal and causing the closure portion at the rim to flow over the inside lip of the valve seat 27 and provide a secondary seal.

Also in keeping with the invention, the primary and secondary seals are augmented and enhanced by a pressure energized seal achieved in the present case by virtue of the configuration of the closure portion of the diaphragm 22 and the associate plunger wherein the inverted dished valve closure portion admits water under inlet pressure in the closed position of the valve to a zone B beyond the valve seat 27.

In the valve closed position (Fig. 2), the end of the plunger 24 is located adjacent the valve seat 27. The inlet water pressure in the zone B acts against and squeezes the thick sidewall 64 of the valve closure which extends vertically above the valve seat, the effect of such inlet pressure being a thinning of the sidewall 64 and flow of the elastomeric material toward the valve seat 27 and crevice 68, to provide a pressure energized seal which augments the primary and secondary seals.

The amount the rubber is squeezed between the valve plunger and seat in the valve closed position, is determined by a number of factors including the height "A" of the sidewall closure portion of the diaphragm, and the clearance between the valve plunger and the valve seat Should the rubber take a compression set after a period of use, the height "A" will be reduced, thus reducing the squeeze on the rubber as the valve is closed. Production tolerances allowed in the manufacture of the parts may also effect the amount of the clearance, and due to production tolerances in some of the assemblies produced, the clearance may be less than in others. Should the amount of the squeeze on the rubber be reduced to zero due to a combination of these factors, in keeping with this invention the fluid pressure in the zone "B" acting to thin the sidewall of the closure portion of the diaphragm serves to overcome the compression set and reestablish the seal at the valve seat. This pressure energized seal is believed to be an important aspect of the present invention and contributes to a valve assembly having long life and capable of operation over a large number of operating cycles without failure.

In providing the pressure energized seal, it is advantageous to have the tubular end portion 70 of the plunger 24 outward of the valve seat 27 as shown, with the inside edge of the tubular end 70 substantially aligned with and almost touching the outside edge of the valve seat in the closed position of the valve (Fig. 2). By having the tubular end 70 virtually touching the valve seat a small peripheral crevice 68 is left for the radially extending supporting section of the diaphragm, and while the inlet pressure in the zone "B" also tends to force the sidewall 64 toward the crevice, the crevice is small enough to prevent the rubber being extruded through it.

Another feature of the dished configuration of the valve closure portion is that such portion is received in the recess within the tubular central end portion 70 of the plunger, which fixes the location of the valve closure portion and insures alignment of the rim of the valve closure portion of the diaphragm with the valve seat. The tubular end portion 70 of the plunger contributes support to the valve closure portion of the diaphragm, which is of soft, pliable elastomeric material so that it is capable of forming a good seal at the valve seat and conforms to the seat even where particle build up or erosion results in an irregular surface at the seat.

In addition to having the valve closure portion configuration hereinbefore described, the diaphragm 22 shown herein and embody- ing the present invention is provided with a convoluted radially extending supporting section 66 extending to the peripheral bead 44 which is clamped between the upper and lower sections of the valve body. In the closed position of the valve as shown in Fig. 2, which is the molded position of the diaphragm, the convoluted supporting section has an inner loop 74 which lies in the outlet chamber 20 and an outer reverse loop 76 which rests against the end wall of the valve plunger outside of the tubular end portion thereof. In the closed position of the valve there is, of course, no water present in the outlet chamber 20 nor any pressure due to water acting against the supporting section 66 of the diaphragm.On the stroke of the valve plunger 24 from the valve closed position to the valve open position shown in Fig. 1, the convoluted supporting section rolls and becomes fully extended in the valve open position where it is pressed by pressure of water in the outlet chamber against the end wall of the plunger and the sidewall 58 of the outlet chamber 20. The end wall 77 of the plunger 24 outward of the tubular portion 70, is concave and conforms to the outer loop 76 of the convoluted supporting section of the diaphragm. The tubular portion 70 of the plunger is rounded. The combination of the rounded tubular end portion 70 and concave end wall 77 provides a sinuous shape (in cross section) for the plunger end outward of the center recess.This is for the purpose of encouraging the desired rolling action of the diaphragm and to provide a continuous smooth backing surface for the diaphragm in the open valve position shown in Fig. 1, such that the diaphragm is flattened against the end of the plunger and the sidewall of the outlet chamber without any stretching.

The diaphragm 22 has a size such that the supporting section 66 when fully extended as shown in Fig. 1 in the open valve position, is flattened against the tubular end 70 and end wall 77 of the plunger and the outlet chamber sidewall 58, by the water pressure in the outlet chamber 20, without any stretching of the diaphragm, and thus without overstressing the diaphragm material, i.e.

the dimensions and shape of the plunger, and the location of the mounting bead are such that the radial extent of the diaphragm supporting section is substantially equal to the radial distance along the plunger end wall and sidewall of the outlet chamber to the clamping bead. In keeping with the present invention, long life of the diaphragm material under operating conditions (particu- larly the supporting section of the diaphragm which flexes during the stroke of the plunger to enable the valve closure portion to move relative to the valve seat) is obtained by a diaphragm and associated plunger construction wherein the stresses in the diaphragm material are held well under the fatigue limit of the material.During each operating cycle, the supporting section of the diaphragm rolls, and the stress points at the tops of the two loops 74, 78 on the supporting section shift radially rather than being concentrated at one point as in a cantilever supporting section. Moreover, the stresses at the stress points in this construction are in the form of tension stresses at the outside of the loop and compression stresses on the inside of the loop with a neutral plane along the middle of the material, without any load on the material due to stretching. These stresses are due solely to the reverse bend required to form the loops and the maximum stress is thus defined.This diaphragm is never stretched by water pressure since the diaphragm is rigidly backed up in its fully extended condition as shown in Fig. 2 when the full water pressure prevails in the outlet chamber, and thus the material of the diaphragm is never stressed above its fatigue limit due to being stretched.

Referring now to Figs. 8-12, to demonstrate that the present invention may be embodied in double line as well as single line type faucet valve assemblies, the invention is shown incorporated in a faucet valve of the mixing valve type for proportioning the flow to an outlet line from separate lines supplying hot and cold water to the valve assembly. Such a mixing valve finds widespread use as a faucet valve for shower heads. In this particular type of valve no means is provided for regulating volume of flow to the shower head, and a separate valve to regulate flow rate is typically used and normally set to provide a constant volume of water to the shower head.The mixing valve embodying the invention enables adjustment of the temperature of the water, and provides the desired arrangement for safety in which initial movement of the operating handle from the off position causes cold water to be supplied to the outlet, further movement of the operating handle causes the proportion of hot water mixed with cold water to be gradually increased, and final movement of the operating handle to the extreme open position causes hot water at the maximum temperature to be supplied to the outlet and the cold water supply substantially closed off.

This mixing valve embodying the invention also provides the desired means for setting a maximum limit on the hot water temperature.

While the embodiment of the invention shown in Figs. 1 and 2 includes a single diaphragm valve assembly, the mixing valve embodiment of this invention includes a pair of similar diaphragm valve assemblies each including an identical diaphragm 22, as illustrated in Fig. 7. Each diaphragm 22 has a valve plunger 124 and 224 and is mounted between the lower section 117 and the upper section 136 of the valve body. The lower section 117 includes a tubular inlet member 126 for hot water and 226 for cold water and the end of the inlet members 126, 226 serve as a hot water valve seat 127 and a cold water valve seat 227. The valve plungers 124, 224 are cammed downwardly from the valve opened to valve closed positions by a rotary cam plate 130 rotated by a stem 112 adapted to carry an operating knob or handle 114 I(shown in dashed lines).When the stem 112 is turned to the closed position, the cam plate 130 produces camming forces that force both the valve plungers 124, 224 downward against the forces tending to raise the diaphragms 22 and open the valve assembly due to the inlet water pressure acting on both diaphragms. That force due to water pressure is utilized to raise the valve plungers 124, 224 to valve open position when the stem is turned toward the open position.The valve plungers 124, 224 are supported for reciprocal movement and restrained against rotational movement along the axis of the respective valve seats in the strokes between valve open and valve close positions, by means such as keys 131 on the exterior of the hot water valve plunger 124 (Fig. 11) received with a sliding fit in key ways {not shown) in the cylindrical inside wall of the plunger chamber in the upper section 136 of the body of the valve assembly.

The upper section 136-of the body 136 has a cylindrical inside wall 137 and the cam plate 130 is similarly cylindrical in shape.

The lower face of the rotary cam 130 has two separate and distinct cam surfaces 128, 228 for operating, respectively, the hot and cold water plungers 124, 224. The hot plunger operating cam surface is provided by a groove 128 of varying depth on the lower face of the cam 130 (Figure 10), while the cold plunger operating cam surface 228 (Figure 8) is provided by concentric rings between which the hot plunger cam groove is formed. The cold plunger cam surface 228 is provided by the bottom or lower edge of these rings which engage the top of the cold water plunger 224.

The hot and cold water plungers are cylindrical at their lower ends and the valve body has cylindrical bores 125, 225 so that the plungers are reciprocably mounted for movement toward and away from the valve seats 127, 227. As previously noted, the hot water plunger 124 has a key 131 as seen in Fig. 11, and the cylindrical bore 125 in the valve body has a cooperating key way, while the configuration of the cold water plunger is irregular and cooperates with the valve body, so that the plungers are mounted for reciprocal movement and restrained against rotational movement. When the plungers 124, 224 are forced by the cams to their positions as shown in Fig. 8, the diaphragms 22 are pressed against the seats 127, 227 and the hot and cold water valves are closed.The hot and cold water plungers 124, 225 each carry upwardly projecting members 129, 229 Figs. 11, 12) which engage the respective cam surfaces on the lower face of the rotary cam. The upwardly projecting member 129 on the hot water plunger has an arcuate shape as shown in Fig. 11 and at the top fits within the cam groove 1281 in the lower face of the rotary cam 130. Thus on rotation of the cam 130 the cam surface 128 is effective to raise and lower the hot water plunger. The upwardly projecting member 229 on the cold water plunger 224 has, as appears in Fig. 12, a triangular shape, and the upper section 136 of the valve body is molded to provide a vertical channel 2291 with a like cross-section such that the cold water plunger is reciprocably mounted while restrained against rotational movement. In Figure 10, the zero reference points for both hot and cold cams are indicated, together with the low and high reference points on both hot and cold cams, to facilitate understanding of their construction.

Since the individual diaphragm valves used in the mixing valve operate in the same fashion and have the same features as the single line faucet diaphragm valve shown in Figs. 1 and 2, the previous detailed description and explanation of features and operation of the diaphragm valve may be referred to and will not be repeated.

The body of the mixing valve assembly may be formed, as shown in Fig. 8, of upper and lower molded plastic sections 117, 136 with the diaphragms 22 mounted between.

The flow path of water is from either or both the inlets 126, 226 to a centrally located outlet passage 140. The mixing valve assembly is constructed for mounting on a fixture (not shown) providing hot and cold water supply lines matched up with the hot and cold water inlets 126, 226 and a single line matched with the outlet passage 140 in the body, for conveying the mixture of hot and cold water to the point of use, such as a shower head or the like. The mixing valve assembly serves as a faucet by providing a water shut-off as well as water temperature regulating function. The mixing valve assembly valve body includes a cover mem- ber 142 which is held on the assembly by the long mounting screws 143 which reach through and screw into tapped holes in the fixture (not shown) on which the assembly is mounted.

The hot and cold cam surfaces 128, 228 provided by the rotary cam plate cooperate respectively with the hot and cold plungers 124, 224 to proportion flow of hot and cold water from the inlets 126, 226 to the outlet 140. The rotary cam plate is operated by means of its stem 112 which in turn receives a knob or handle shown in dashed lines in Fig. 8. A longitudinal rib 113 on the stem is shown against an off position stop 115 in Fig. 9, and when turned through 270 comes to bear against the full on stop 1151. One of the features of the invention, described hereinafter, is the provision of means to adjust the full on position stop 1151, to enable setting the maximum hot water temperature of the mixed water.

Thus, while the cam surfaces and cooperating plunger surfaces may be changed as desired, it is preferred for safety reasons that as the stem is rotated through about the first 10 , the water is turned on by raising solely the cold water plunger, and thereafter the water temperature is gradually increased through a normal range of usable temperatures from cold through hot and defined by about 200 of rotation of the cam.The final about 600 of cam rotation defines a range of hot water temperatures to the final position where the stem rib 113 is against the full on stop 1151 where the hot water line valve is full open and the cold water line valve is fully dosed. To achieve this kind of mixed water temperature characteristic requires dwell regions and sloping regions on both cam surfaces appropriately located within the 270 of active cam surface, and operating in combination, to move the plungers and so proportion hot and cold water flow as to obtain the mixed flow temperature characteristic desired, as will be fully understood by a man skilled in the art.

To provide means for adjustment of the maximum hot water temperature, an adjustable circular stop plate 143 is provided, mounted on top of the cover member 142 and held in place by a pair of set screws 144. A triangular shaped member 145 carried by the cover member 142 and projecting into the center recess 146 in the cover provides the off position stop 115 against which the rib 113 on the stem 112 bears.By loosening the set screws 144, the stop plate 143 may be rotatably adjusted to suit the full on stop 1151 (provided by a triangular shaped member 147 carried by the stop plate 143) from the position shown in solid lines in Fig. 9 where it allows a full 2700 of rotational movement of the stem, to a position where it limits the movement of the stem to a smaller angle, for example the position shown in dashed lines where the movement of the stem is restricted to about 1700. The set screws 144 pass through arcuate slots 148 in the stop plate 143 to enable its rotational adjustment when the set screws are loosened, and the screws are then tightened down after the adjustment to fix the position of the member 147 and the full on stop 1151. The stop plate thus enables setting a maximum hot water temperature, which is an important feature.The stop plate has a circular projecting rib 149 on its lower surface that is received in a circular groove 150 in the cover for locating purposes, and has a ribbed periphery 151 to facilitate its being rotatably adjusted. As shown in Figure 9, the triangular element 145 carried by the cover member 142 and providing the off position stop 115, underlies and is coincident with the triangular member 147 carried by the stop plate 143 when located to permit full 270 movement of the stem 112; the triangular element 145 which is carried by the cover member 142, is located in a fixed position to define the off position stop. Thus, the on position stop 1151 is adjustable without disturbing the fixed location of the off position stop 115.

WHAT WE CLAIM IS: 1. A faucet valve assembly, including a valve body having upper and lower sections, said lower section having a chamber

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. high reference points on both hot and cold cams, to facilitate understanding of their construction. Since the individual diaphragm valves used in the mixing valve operate in the same fashion and have the same features as the single line faucet diaphragm valve shown in Figs. 1 and 2, the previous detailed description and explanation of features and operation of the diaphragm valve may be referred to and will not be repeated. The body of the mixing valve assembly may be formed, as shown in Fig. 8, of upper and lower molded plastic sections 117, 136 with the diaphragms 22 mounted between. The flow path of water is from either or both the inlets 126, 226 to a centrally located outlet passage 140. The mixing valve assembly is constructed for mounting on a fixture (not shown) providing hot and cold water supply lines matched up with the hot and cold water inlets 126, 226 and a single line matched with the outlet passage 140 in the body, for conveying the mixture of hot and cold water to the point of use, such as a shower head or the like. The mixing valve assembly serves as a faucet by providing a water shut-off as well as water temperature regulating function. The mixing valve assembly valve body includes a cover mem- ber 142 which is held on the assembly by the long mounting screws 143 which reach through and screw into tapped holes in the fixture (not shown) on which the assembly is mounted. The hot and cold cam surfaces 128, 228 provided by the rotary cam plate cooperate respectively with the hot and cold plungers 124, 224 to proportion flow of hot and cold water from the inlets 126, 226 to the outlet 140. The rotary cam plate is operated by means of its stem 112 which in turn receives a knob or handle shown in dashed lines in Fig. 8. A longitudinal rib 113 on the stem is shown against an off position stop 115 in Fig. 9, and when turned through 270 comes to bear against the full on stop 1151. One of the features of the invention, described hereinafter, is the provision of means to adjust the full on position stop 1151, to enable setting the maximum hot water temperature of the mixed water. Thus, while the cam surfaces and cooperating plunger surfaces may be changed as desired, it is preferred for safety reasons that as the stem is rotated through about the first 10 , the water is turned on by raising solely the cold water plunger, and thereafter the water temperature is gradually increased through a normal range of usable temperatures from cold through hot and defined by about 200 of rotation of the cam.The final about 600 of cam rotation defines a range of hot water temperatures to the final position where the stem rib 113 is against the full on stop 1151 where the hot water line valve is full open and the cold water line valve is fully dosed. To achieve this kind of mixed water temperature characteristic requires dwell regions and sloping regions on both cam surfaces appropriately located within the 270 of active cam surface, and operating in combination, to move the plungers and so proportion hot and cold water flow as to obtain the mixed flow temperature characteristic desired, as will be fully understood by a man skilled in the art. To provide means for adjustment of the maximum hot water temperature, an adjustable circular stop plate 143 is provided, mounted on top of the cover member 142 and held in place by a pair of set screws 144. A triangular shaped member 145 carried by the cover member 142 and projecting into the center recess 146 in the cover provides the off position stop 115 against which the rib 113 on the stem 112 bears.By loosening the set screws 144, the stop plate 143 may be rotatably adjusted to suit the full on stop 1151 (provided by a triangular shaped member 147 carried by the stop plate 143) from the position shown in solid lines in Fig. 9 where it allows a full 2700 of rotational movement of the stem, to a position where it limits the movement of the stem to a smaller angle, for example the position shown in dashed lines where the movement of the stem is restricted to about 1700. The set screws 144 pass through arcuate slots 148 in the stop plate 143 to enable its rotational adjustment when the set screws are loosened, and the screws are then tightened down after the adjustment to fix the position of the member 147 and the full on stop 1151. The stop plate thus enables setting a maximum hot water temperature, which is an important feature.The stop plate has a circular projecting rib 149 on its lower surface that is received in a circular groove 150 in the cover for locating purposes, and has a ribbed periphery 151 to facilitate its being rotatably adjusted. As shown in Figure 9, the triangular element 145 carried by the cover member 142 and providing the off position stop 115, underlies and is coincident with the triangular member 147 carried by the stop plate 143 when located to permit full 270 movement of the stem 112; the triangular element 145 which is carried by the cover member 142, is located in a fixed position to define the off position stop. Thus, the on position stop 1151 is adjustable without disturbing the fixed location of the off position stop 115. WHAT WE CLAIM IS:

1. A faucet valve assembly, including a valve body having upper and lower sections, said lower section having a chamber

with an outlet passage for water, and an inlet for water extending into said chamber, the end of said inlet providing an annular valve seat, a movable valve plunger non-rotatably and slidably supported within the upper section of said valve body for reciprocal movement along the axis of said valve seat between valve open and valve closed positions, said valve plunger having a recess in one end portion said recess being concentric with and having a larger inside diameter than the inside diameter of said valve seat, and a diaphragm of elastomeric material extending across said chamber and gripped at its outer edge by said valve body to seal and provide one end of the chamber, said diaphragm having an upwardly projecting valve closure portion received in the valve plunger recess with a downward facing surface engaging the valve seat in the valve closed position of the plunger, said closure portion of the diaphragm extending longitudinally beyond said end of the valve plunger and said valve plunger having a valve closed position wherein said downward facing surface engages and is pressed against said valve seat to provide a primary seal and to cause the closure portion to overhang the inside lip of the valve seat, said diaghragm further having a convoluted supporting section extending radially from said closure portion which rolls during the stroke of the valve plunger, the open valve position of the valve plunger providing clearance between the valve seat and said surface of the valve closure portion to admit water from the inlet which flows radially across the valve seat into the chamber and out the outlet passage, said plunger having an end wall extending outwardly from said end portion against which the supporting section of said diaphragm is pressed by water pressure in the valve open position of said plunger, the combination of said end portion and end wall of the plunger, and the side wall of said chamber, in the valve open position of the valve plunger, providing a continuous surface at least equal in radial extent to the supporting section of the diaphragm and rigidly backing up the supporting section in the valve open position of the valve plunger and holding said supporting section against stretching under the pressure of water in the chamber.

2. A faucet valve assembly as claimed in claim 1, wherein said upward projecting valve closure portion has an inverted dished shape with a side wall received in the valve plunger recess and a rim engaging the valve seat in the valve closed position of the plunger, and the inverted dished closure portion of said diaphragm admits water under inlet pressure in the closed position of the valve to a zone beyond the valve seat, the end of the plunger being located closely adjacent the valve seat and leaving a peripheral crevice through which the supporting section of the diaphragm extends, and the water pressure in said zone acting outwardly and squeezing said side wall of the valve closure portion against a side wall of the plunger recess, said valve closure side wall of elastomeric material being sufficiently pliable to flow under water pressure toward the valve seat to provide a pressure energized seal augmenting the primary seal.

3. A faucet valve assembly as claimed in claim 2 wherein said upper and lower sections of said valve body telescope together, said diaphragm is gripped at its outer edge between said telescoped valve body sections, said valve body is generally cylindrical, and said body has sealing rings at longitudinally spaced locations on the exterior of said body to seal said body in a like-shaped cavity, so that said faucet valve assembly is replaceable and provides a dry stem, replaceable valve cartridge.

4. A faucet valve assembly as claimed in claim 3, wherein said valve plunger has a tubular end portion with said recess within said tubular end portion, the inside edge of said tubular end portion of the valve plunger is substantially aligned with the outside edge of the valve seat, and said plunger has an end wall extending outwardly from said tubular end portion against which the supporting section of said diaphragm is pressed by water pressure in the valve open position of said valve plunger, the combination of said tubular end portion and end wall of the plunger, and the side wall of said chamber, in the valve open position of the valve plunger, providing a continuous surface at least equal in radial extent to the supporting section of the diaphragm and rigidly backing up the supporting section in the valve open position of the valve plunger and holding said supporting section against stretching under the pressure of water in the chamber.

5. A diaphragm valve assembly substantially as hereinbefore described and as shown in the accompanying drawings.