GB2251056A - Mixing valve cartridge - Google Patents

Abstract

Rotatable modular cartridge (60) for incorporation in a mixing valve (10) and shown in Figure 5 comprises a lower section (62) carrying a volume control valve plate (58) at its lower inlet end, rotation of the whole cartridge controlling inflow therethrough from supply ports of the valve; and an upper section (140) housing a temperature control valve plate (150) carried for rotation with the cartridge but also independently rotatable relative thereto by its own control stem (160), the latter plate regulating the proportions of hot and cold water passing to a mixing chamber of the cartridge for eventual outflow from the valve. Said operating stem for the temperature control plate is received coaxially in an annular volume control stem (180) for rotating the entire cartridge. <IMAGE>

Description

MIXING VALVE CARTRIDGE The present invention relates to mixing valves for tub spouts and shower heads and more particularly to a modular cartridge for a pressure balanced, volume controlled and temperature controlled mixing valve. The invention is particularly, but not exclusively, applicable to the mixing valve described and claimed in our co-pending patent application 9011547.8 serial number 2232231 of even date herewith, hereinafter referred to as "GB-A-22322231", out of which this present application is divided.

Single handle mixing valves have become commonplace in today's plumbing market. However, many compromises have been built into mixing valves such as the compromise between large flow rates and easy temperature control.

Furthermore, mixing valves are often built without pressure balance valves. Previous mixing valves that have been designed with a built-in pressure balance mechanism are bulky and not adequately packaged in a compact housing. However, lack of a pressure balance valve can result in rapid change of water temperature when either the hot water supply or the cold water supply pressure drops. The pressure drop can occur if another faucet, dishwasher, or washing machine is turned on, or a toilet is flushed. When either the cold or hot water supply pressure changes, discomfort can result if a person is taking a shower.

Furthermore, previous pressure balance valves have been complicated mechanisms that cannot be easily repaired or have their parts replaced.

The object of the invention is to provide a cartridge to form part of an easily assembled and compact mixing valve which provides readily controlled full adjustment of the volume and temperature.

According to the invention there is provided a cartridge as defined in Claim 1 of the appended claims.

An example of the invention is now more particularly described with reference to the accompanying drawings in which Figure 1 is- a perspective view of a mixing valve including a cartridge, Figure 2 is a longitudinal section of the valve, Figure 3 is a top plan view of a housing member of the valve, Figure 4 is a fragmentary, bottom perspective view of a lower portion of the cartridge, Figure 5 is an exploded top perspective view of the cartridge and associated components, Figure 6 is a fragmentary, cross-section on line 6-6 of Figure 2, Figure 7 is an exploded top perspective view of the lower cartridge portion and its interior parts, Figure 8 is a cross-section of the cartridge on line 8-8 of Figure 2 with a temperature control valve plate in an intermediate position, Figure 9 is like view with said valve plate rotated to a cold position, Figure 10 is a cross-section on line 10-10 of Figure 2, and Figure 11 is a side elevation and part section of an alternate embodiment of the upper cartridge section.

Referring now to Figure 1, a mixing valve 10 of the kind described in GB-A-2232231 has a housing 12 connected to fitting 14 which is usually mounted behind a shower wall 16. The fitting 14 has a cold water supply nipple 18 and a hot water supply nipple 20, and outlet nipple 22 leading to a tub spout (not shown) or outlet nipple 24 connected to a shower riser (not shown). Outlet nipple 24 is in fluid communication with outlet nipple 22. The body has a cosmetic collar 26 which is mounted as shown in Figure 2 via a friction sealing ring 28 that is fitted in a groove 30 in housing 12. A collar 32 threadably engages the housing 12. A volume control handle 34 having a lever 36 is rotatable about a central longitudinal axis 64 through housing 12.Temperature control knob 38 is also rotatably mounted at the outer distal end of the volume control handle 34 and is rotatable about the same longitudinal axis 64. Knob 38 can also be referred to as a handle.

The internal valving is more clearly shown in Figures 2-10. For simplicity of reference, the temperature control knob 38 is located at the top of the mixing valve as illustrated in Figure 2. All reference to top, bottom, upper and lower is made in reference to Figure 2 even though its perfectly acceptable to mount the mixing valve in other orientations as illustrated in Figure 1. Referring now to Figures 2 and 3, the housing 12 has a cavity 40 with a supply port 42 in communication with a water supply through nipple 18 and supply port 44 in communication with a water supply through nipple 20.

The supply ports 42 and 44 pass through an end axial positioned wall 44 at the bottom of the cavity 40 and faces the open end 41 thereof. As shown in Figure 2, inner sealing elements 46 are mounted in counterbores 48 of the two ports 42 and 44. A discharge port 50 also extends through the axially positioned wall 45 and in communication with the two outlet nipples 22 and 24.

Two outer sealing rings 52 are fitted into annular grooves 54 in the wall 45 and are positioned about the inner sealing elements 46 such that the outer sealing rings 52 are interposed between the ports 42 and 44 and discharge port 50. The outer sealing elements 52 are spaced from the inner sealing elements 46 substantially the diameter of the inlets 56 through a volume control valve plate 58.

The volume control valve plate, made from stainless steel, is affixed against rotation to a cartridge assembly 60 which is rotated by handle 34 as described later. The handle 34 as it rotates about axis 62 also rotates the cartridge about the longitudinal axis 62 such that the volume control plate 58 also rotates about an axis 62 such that inlets 56 can become fully aligned with supply ports 42 as shown in Figure 2 at the full on position or can be closed to a full off position.

Furthermore in the intermediate partially on position between the full on and full off, outer seals prevent any water about inner seal 46 from reaching discharge port 50 without first passing through the cartridge 60 as explained below. In addition, cross flow between ports 42 and 44 is prevented. The outer sealing elements 52 effectively prevent water from bypassing cartridge assembly 60 is illustrated in Figure 6.

As shown in Figures 4 and 5, cartridge assembly 60 has a lower section 62 with two bottom end flanges 66 that have notches 68. A lateral groove 69 is spaced above notch 68 so that a retaining lip 71 is formed therebetween. The notches 68 receive corresponding tabs 70 in the volume control valve plate 58 to rotationally affix the volume control valve plate 58 to the cartridge assembly 60. The distal ends 73 of tabs 70 are bent upward and inward to be received ;in groove 69 so that the plate 58 is retained on section 62 via lips 71. As shown in Figure 2, appropriate seal rings 72 are interposed between each inlet 56 and the valve housing lower section 62 to prevent leaking therebetween.

Referring now to figure 7, the lower section 62 has passages 74a and 74b leading to a first section 76 and second section 78, respectively, of a spool type pressure balance proportioning valve 80. The spool type valve 80 has an outer spool 82 with five sealing rings 84 about its outer circumference to fluidically seal passage 74a and passage 74b. The outer spool 82 has axially spaced apertures 86, 88, 90 and 92 aligned with the respective passages 74b, 75b, 75a and 74a. A sliding piston 94 also has apertures 96 therethrough which communicates sections 76 and 78 with respective grooves 98 and 99 which are in selective communication with the passages 74a, 74b and 75a and 75b via the apertures 86, 88, 90 and 92 in the outer spool. In this way the pressure within each passage 75a and 75b is substantially equalised via the movement of piston 94 of the spool type valve 80.

The lower section 62, for ease in manufacturing, is made from two halves 100 and 102 with each half having a flange 104 and 105 that has an aperture 108 and 109 that receives a threaded fastener 110 which is secured to the threaded apertures 111 and 112 in the flanges 113 and 114. Each half 100 and 102 has a cavity 116 and 118 sized to receive half of outer spool 82. Each half has a pair of laterally extending prongs 119 which snap fittingly are received into apertures 122 in a lower flange 124 of an upper cartridge section 120 as shown in Figure 4.

Referring back to figures 2 and 5, a gasket 126 has two apertures 128a and 128b in communication with passages 75a and 75b, respectively. The top portion of lower section 62 has a contoured shoulder 129 that receives a lower flange 131 of an intermediate cartridge section 130. The cartridge section 130 has two intermediate ports 132 and 134 therethrough in communication with respect to passages 75a and 75b. The gasket 126 prevents cross flow between the passages 75a and 75b. Two sealing elements 136 identical to sealing elements 46 are placed within the intermediate cartridge member 130. The upper end 138 of the intermediate cartridge member 130 abuts against an annular radially extending shoulder 140 in the upper cartridge section 120. A reduced diameter section 142 provides a mixing chamber 144 wherein the temperature control valve plate 150 is seated.The temperature control valve plate 150 has a valving surface with a crescent aperture 152 therethrough and an undercut 154 which allows the mixing of water therein. The crescent aperture 152 extends substantially over 180 degrees radially about the control valve plate 150. A supporting rib 156 extends within the undercut 154 to the outer periphery 157 of the temperature control valve plate 150. More than one rib 156 may be employed and circumferentially spaced about plate 150.

The temperature control valve plate 150 fits within reduced diameter section 142 of the upper cartridge section 140. The intermediate cartridge member 130 fits within larger lower section 162 of cartridge section 120.

The plate 150 and member 130 are inserted from the lower end of the upper cartridge section 120. The upper end of the upper cartridge section 140 has a radially extending inner flange 164 to prevent the temperature control valve plate 150 from exiting through the top end 166. The gasket 126 is then seated within lower flange 131 of member 130 and the lower section 62 is snap fitted in place to upper section 140. Valve plate 58 is mounted within key notches 68 to form the modular cartridge assembly 60.

As shown in Figures 2, 8 and 9, the outer periphery 157 of valve plate 150 is sized to provide an annular clearance or passage 170 clearance with the reduced diameter section 142. The passage 170 is in communication with a discharge outlet 172 formed between the upper section 120 and lower section 62 of the cartridge assembly 60 as shown in Figure 4. The discharge outlet 172 is in communication with the discharge port 50 via an annular chamber 177 formed about the lower section 62 within the cavity 40. Discharge port 50 is in fluid communication with outlet nipples 22 and 24 of fitting 14 in a conventional manner.

The cartridge assembly 60 is fitted within the open distal end 41 of cavity 40 so that plate 58 lays flat against seals 46 and 52. Referring back to Figures 2 and 5, an operating stem 160 is then positioned in seat 159 via its complementary shaped mating section 161. The seat 159 and section 161 may have rotationally asymmetric shapes or an eccentric pin and hole arrangement may be used to assure that stem 160 has only one orientation with resect to seat 159. An O-ring 173 is fitted within groove 174 of stem 160. The stem 160 also has a rounded seat section 176. An annular volume control stem 180 is then slipped over stem 160 via its central opening 182 and is in sealing engagement via sealing O-ring 173 to prevent leakage therebetween.The seat section 176 rotatably seats in recessed seat 186 of stem 180 for allowing relative rotation of the volume control stem 180 with the temperature control stem 160. The temperature control stem 160 is longer than stem 180 so that it extends beyond the upper end 184 of stem 180. The stem 180 has a radially extending key 188 which fits within notch 167 in upper end 166 of the upper cartridge section 120. Rotation of stem 180 rotates the cartridge assembly 60. A sealing ring 192 fits within groove 189 about the stem 180.

In an alternate embodiment as shown in Figure 11, the upper section 120 and volume control stem may be made as an integral upper cartridge and volume control stem member 320. Member 320 has rib 309 at reduced diameter section 342. The volume control stem section 360 has a threaded section 321, seat section 316, and groove 389 that receives seal 192. The temperature control stem 160 is mounted from lower end 324 that has aperture 322 that receives lower cartridge section 62 and extends through aperture 384. Use of member 320 will form a cartridge assembly that includes a volume control stem and a temperature control stem.

A housing cap 190 is then placed over the cartridge assembly 60. The housing cap 190 has an upper inwardly extending flange 206 and a central aperture 208 therethrough to allow the volume control stem 180 and temperature control stem 160 to extend therethrough. The O-ring 192 seals aperture 208 against leakage. The cap 190 has a lower sealing flange 194 which seats an O-ring 196 and has an outer flat seating flange 198 that has a key- 199 that fits within a slot 201 at the open distal end 41 of the housing 12 as shown in Figure 11. The housing 12 has a threaded section 203 which threadably secures the collar 32. The collar 32 has an inner flange 204 which abuts against the flange 198 of the cap 190 to secure the cap in place.Securement of the cap 190 in place maintains the cartridge 60, volume control stem 180, and temperature control stem 160 in an integrated assembled unit as shown in Figures 1 and 2. Seal 196 prevents leakage between the housing 12 and cap 190.

As shown in Figure 10, the cap 190 also has two internal longitudinal shoulders 210 and 212 which are about 90 degrees apart'and are dimensioned to engage key 188 in the volume control stem 180 and an aligned rib 209 of upper cartridge section 120. A shoulder 211 is radially placed inward to interfere with rib 209 and key 188 so that the cap 190 cannot be incorrectly placed over cartridge 60 and to assure rib 209 and key 188 are between shoulders 210 and 212.

Stem 180 is rotated by handle 34 which has an asymmetric opening 214 shaped to snugly receive a complementary shaped section 216 of stem 180. A lock nut 218 can then be threaded onto the threaded section 220 of stem 180 to secure the handle 134 onto stem 180.

The handle 34 has an upper section with a seat 222 with a splined section 224 thereabout and an axially extending stop shoulder 226. A rib 227 radially extends inward from shoulder 226. An arcuate hot water stop ring 228 has a complementary splined section 230 which can adjustably be positioned and secured to the splined section 224 about a number of rotated positions. The ring 228 has a stop shoulder 232 and arcuate rib 236.

The ring 228 abuts against rib 227 to be frictionally engaged in place in seat 222.

The interchangeable mounting of temperature control knob 38 is described in GB-A-2232231 and is also described and claimed in our co-pending patent application of even date herewith and als-o divided from GB-A-2232231.

The operation of the assembled valve incorporating the cartridge 60 is also fully described in GB-A-2232231.

Because the temperature control valve plate 150 is carried within the cartridge 60, rotation of the cartridge 60 carries, or rotates, the temperature control plate 150 therewith so that there is no temperature change as volume control handle 34 is rotated. The temperature control handle 38 also rotates with rotation of volume control handle 34. The temperature knob 38 can be independently rotated to independently move the valve plate 150 to adjust the temperature between the cold stop rib 226 and the hot stop shoulder 232 of member 228.

If pressure in the cold or hot water line suddenly drops, the pressure balance valve 80 of the cartridge immediately responds to the pressure drop to maintain the same relative flow rates through both inlets 56 in the volume control valve plate. The pressure balance valve 80 prevents sudden temperature changes due to pressure changes within the hot and cold water supply lines that can be caused by diversion of some of the hot or cold water.

The present invention provides a cartridge for a reliable, compact, and versatile valve assembly that has pressure balancing, volume control, and temperature control. The mixing valve is controlled by two coaxially mounted handles that are conveniently placed at the end of the valve assembly. Furthermore, the maximum hot water temperature which can be achieved through control of the temperature control knob can be conveniently adjusted without disassembly of the cartridge or mixing valve housing. Maintenance of the mixing valve is easy with replacement of the modular cartridge being available rather than labour intensive disassembly of all of the valve parts.

Claims (4)

1. A rotatable modular cartridge for a mixing valve housing characterised by: a lower cartridge section having a first flat valve plate surface at an inlet end thereof for controlling flow from first and second supply ports in said mixing valve housing; said lower cartridge section having passage means in fluid communication with said outlet end; an upper cartridge section snap fitted to said lower cartridge section; said upper cartridge section receives a second flat valve plate surface operably mounted to said passage means; an integral upper end of said upper cartridge section defines a first operating stem on which a control handle is mountable for rotating said cartridge and said first valving surface; said first operating stem has an aperture therethrough for receiving a second operating stem that is operably affixed to said second valve surface;; said cartridge has an outlet means for fluid downstream of said second valve surface; one of said first or second valve surfaces operable to control total fluid flow through said cartridge; and the other of said first or second valve surfaces operable to control relative proportions of fluid flow from said first and second supply ports in said mixing valve housing.

2. A rotatable modular cartridge for a mixing valve housing, said cartridge comprising: a) a lower cartridge section having a first valve surface at an inlet end thereof, said surface having two inlets for operatively controlling flow from first and second supply ports of the housing, and defining passage means including two passages each leading from a respective said inlet to communicate with an outlet end of the lower section; b) an upper cartridge section snap fitted to the lower section defining a mixing chamber and a fluid outlet means, and having an integral upper end including a first operating stem on which a control handle is mountable in use for rotation of the cartridge, said first stem having an axial through aperture; and c) a valve element received in said upper section and having a second valve surface operable to coact with the passage means of the lower section upstream of the mixing chamber, said element being rotatable coaxially relative to the first valve surface by a second operating stem received in said through aperture of the first stem whereby the first valve surface is rotatable to control total fluid flow through the cartridge in use, and the second valve surface is rotatable coaxially with respect to the first surface to control the relative proportions of fluid flow from said two passages.

3. A cartridge as in Claim 2 wherein said first valve surface is provided on a valve plate having two apertures therethrough and snap fitted onto the remainder of the lower cartridge section and affixed thereto for rotation therewith.

4. A cartridge as in Claim 1, 2 or 3 including a pressure balance means operably mounted in said cartridge between the first and second valve surfaces and rotatable with said cartridge for maintaining approximately equal pressures of fluid to said intermediate first and second ports.