CA1043220A - Pressure compensating device for mixing faucets - Google Patents

Abstract

PRESSURE COMPENSATING DEVICE FOR MIXING VALVES

Abstract of the Disclosure:

A pressure compensating device is disclosed for mixing valves. The device includes a diaphragm against which the medium to be compensated flows in a housing. The diaphragm is fitted with a throttle plate of flexible material on each side.
Each throttle plate includes apertures which widen towards the diaphragm to aid in pressure compensation. Each throttle plate is securely fastened at its edges to the diaphragm and the casing and is secured at its center by a pin and spacers to the center of the diaphragm.

Description

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; - 2 - L. Nordentoft-4 (Rev.) BACKGROUND OF THE INVENTION
1. Field of the Invention The invention relates to the provision of pressure compen-sation for mixing valves and similar devices employing a dia-phragm against which the medium to be compensated flows in a housing.
Such pressure compensation devices are required, in parti-cular, for use in hot and cold water mixing valves in the field of sanitary ware. As a rule, such devices are arranged in the hot and cold water pipes before the actual mixing control for hot and cold water. The primary function of these devices is to compensate for variations in pressure caused by changes in the cross-sectional flow which normally occur in water pipes and j thus to ensure that a constant mixture can be obtained in the `-mixing valve and that the emergent water mixture will have a ~-'l ~'' :~:' , `, constant temperature.

2. Description of the Prior Art .
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A device of thic kind is descrlbed in the German Patent ~,; i Specification No. 202,150. ~ccording to that Specification, a piston sealed with a packing collar is movably mounted in a cy-linder. In the direct~on of its axis, the piston has a valve cone, which works in con~unction with a valve seat arranged in the cylinder casing, on a valve stem at each side. When the . ~ - . . .
pressure in the water ~upply pipe changes, the difference in ~-¦ pressure causes the piston to move in the cylinder, changing the flow cross-sections at both valves conversely.

It is also known by virtue of the German examined applica-l .. .: .
~ 25 tion publication No. 2,156,980 that a diaphragm has to be pro-:~ ,,, ,' . ' ' - 2 - ~ ~ ~
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- 3 - L. Nordentoft-4 (Rev.) vided to control the pressure compensation, this diaphragm being coupled to a double valve cone. When using this double valve cone, it is essential that the cone be mounted sealed with a sealing ring to separate the two media in the casing.
In the case of these known devices, it is disadvantageous that the control elements have to be movably mounted with packing rings in the casing so that these contxol elements become tight in a relatively short period of time, particularly in the case of sanitary fittings, because of impurities or lime precipitations from the water and their actuation responsiveness falls consi-derably or even fails completely because the packing ring sticks.
SUMMARY OF THE INVENTION
A pressure compensation device for fluid mixing valves com-prises~ a hollow housing including first and second inlet openings thereon respectively communicating with first and second outlet lS openings thereon. A flexible diaphragm is mounted within the housing and separates the first inlet and the first outlet from the second inlet and the second outlet, thereb~ to form first and ~econd chambers in the housing separated by the diaphragm.
Eaah chamber includes a flexible throttle plate fixedly mounted ; 20 at it~ periphexal edge portion to the chamber thereby sealingly separating the inlet opening rom the outlet opening, and having a plurality of tapered apertures therein which open toward said outlet opening for conducting fluid therethrough. The cross-3~ sectional area of said apertures decreases when the throttle 3 25 plate flexes toward said outlet opening in response to fluid pressure at the inlet opening. Means cooperate with the diaph-ragm for interconnecting the throttle plates wherein translation of one of the plates provides an opposite translation of the , _ 3 _ ;., .' '~

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- 4 - L. Nordentoft-4 (Rev.) other of the throttle plates, whereby the other of said throttle plates flexes away from its corresponding outlet opening when the one of the thxottle plates flexes toward its corresponding outlet opening. -~
By forming the pressure compensation plates of a suitable, flexible material such as, for example, rubber, it can be brought ;
about that the second line is also closed if the pressure drops drastically or if the liquid supply is completely exhausted such as can occur, for example, in the event of water supply failure 10 in a pipe. In this way a safety mechanism against scalding or ~ -cold shock is provided. ~ -Description of the Drawings An embodiment of the invention will be described in greater detail below in conjunction with the figures, in which:
Figure 1 shows the longitudinal section of a pressure com-~ensation device; ;~;
Figure 2 shows a section through the line A-B in Figure l;
~igure 3 shows part o a throttle plate with segment-like tapered ring apertures; and, `
Figure 4 shows part of a throttle plate with pyramid-shaped ; ;
apertures.
Description of a Preferred Embodiment ~ A pressure compensating element is housed in a casing 1 with i inlet apertures 10 and 11 and drain-off apertures 12 and 13 in a drill hole 9. This pressure compensat~ng element consists of a diaphragm 2 firmly fixed and sealed centrally in the casing along ~ -with two throttle plates 3. The throttle plates are connected to the diaphragm by means of a pin S and spacers 6 for spacing. To :`1 . ,~
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- 5 -provide a tight fit in the clrill hole 9 in the casing 1, the throttle plates are tightly fitted to the ~pacer rings 7, provided with apertures 8, by a screwed in cover 14O The thro~tle plates ; have tapered apertures 4 widening towards the diaphragm 2 on a hole S circle lS.
If two media, for example, hot and cold water, are admitted to the throttle device, the pressure compensation device suf~ers no~distortion if the pressure~ are the same (as shown in Figure 1).
If there is a difference in pressure, the diaphragm ~ i~ deflected towards the side on which the lesser pressure prevails. The two throttle plates 3 are coupled to the diaphragm by the pin 5 and the spacers 6 and are deformea in a manner correspondlng to that of the diaphragm. Thus, the tapered drill holes 4 on the ~ressure-increase side are decreased in cross-section and those on the preæsure- .
lS decrease side are lncreased so that the two pressure~ are balanced.
Because of their correspondingly soft form, the diaphragm and the throttle plates can also shut off the second remaini.ng pre~ure source if the first source fails completely. This provides ` security against scalding or cold shocks which is necessary in the ¦ 20 case of sanitary ~.itting~, in particular thermostatically controlled `I mixing valves, to prevent injuries to persons. Throttle plates are~
1 shown in Figures 3 and 4 in which the a~erture~ of the one are il shown as segment-like, tapered ring shaped, 4b, whereas those of the other are pyramid-shaped 4a. The present invention is not restricted i 25 to~the field of sanitary fittings but can also be used to provide pre~sure compensation for gases, etc.
While the principles of the invention have been described above in connection with specific apparatus and application, lt is ~i to be understood tha~ this description i~ made only by way of example ~ 30 and not a~ a limitation on the scope of the invention.
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Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A pressure compensation device for fluid mixing valves comprising:
a hollow housing including first and second inlet openings thereon respectively communicating with first and second outlet openings thereon;
a flexible diaphragm mounted within said housing and separating said first inlet and said first outlet from said second inlet and said second outlet, thereby to form first and second chambers in said housing separated by said diaphragm;
each chamber including a flexible throttle plate mounted therein, said throttle plate being fixedly mounted at its peri-pheral edge portion to said chamber thereby sealingly separating the inlet opening from the outlet opening, and said throttle plate having a plurality of tapered apertures therein which open toward said outlet opening for conducting fluid therethrough and wherein the cross-sectional area of said apertures decreases when said throttle plate flexes toward said outlet opening in response to fluid pressure at said inlet opening; and means cooperating with said diaphragm for interconnecting said throttle plates wherein translation of one of said throttle plates provides an opposite translation of the other of said throttle plates, whereby said other of said throttle plates flexes away from its corresponding outlet opening when said one of said throttle plates flexes toward its corresponding outlet opening.

2. The device according to claim 1, wherein said diaphragm and said throttle plates are concentrically mounted within a generally cylindrical portion of said housing and wherein said

Claim 2 (con't) means for interconnecting said throttle plates comprises a pin coaxially mounted within said housing with each end of said pin being fastened to a respective one of said throttle plates and said pin being carried by said diaphragm in force transmitting relationship therewith.

3. The device according to claim 2, wherein said pin carries a pair of coaxially mounted spacers respectively mounted in one of said chambers between one of said throttle plates and said diaphragm.

4. The device according to claim 3, in which said apertures are formed as annular angularly spaced segments.

5. The device according to claim 3, in which said apertures are formed as angularly spaced four-sided pyramidal-shaped holes.