Water flow control unit in mixing valve for hot and cold water

Abstract: The invention relates to a water flow control unit in mixing valves for hot and cold water comprising two overlapping ceramic disk (11,12) one of which is fixed and the other movable. The fixed disk (11) has two inlet holes (15,16) which are substantially of uniform width and are symmetrically cut, with respect to a water dividing partition (19), into one half of the same disk. The fixed disk (11) also has an elliptic shaped outlet hole where one part is placed between the two inlet holes or openings (15,16) and the other part extends into the other half of the fixed disk. The movable disk (12) has a mixing chamber defined by a circular part (18a) off-centre from the middle of the same disk and a communicating polygonal part (18b).

Description: The present invention relates to single-control mixing valves for hot and cold water and in particular to a water flow control unit in said valves, a unit which comprises two overlapping ceramic disks, one of which is fixed and the other movable. A water flow control unit of the above-mentioned type is known, for example, from FR-A-2 532 394. In fact, this document discloses, and constitutes the preamble of claim 1, a water flow control unit in mixing valves for hot and cold water which comprises, inside a cartridge type body, two overlapping disks, one of which is fixed and the other is movable on top of the fixed one through an operating lever, and wherein: the fixed disk has two separate water inlet holes or openings for hot and cold water and an outlet hole or opening for hot, cold or mixed water; the movable disk has a mixing chamber designed to connect one or both the water inlet holes or openings with the outlet hole; said mixing chamber is open on the side of the fixed disk and closed at the top by a disk-cover to which the operating lever is connected; said two water inlet holes or openings are substantially of uniform width and are cut into one half of the fixed disk symmetrically with respect to a water dividing partition having a radial orientation; the mixing chamber of the movable disk is defined by a circular part off centre from the middle of the movable disk and a communicating polygonal part, said circular part having a smaller radius than the inside radius of the inlet holes or openings, and the outlet hole or opening of the fixed disk lies at least partially under said mixing chamber of the movable disk. Such a known device, however, does not allow to reach optimal flow and mixing results owing to the shapes of the water inlet and outlet holes of the overlapping disks and it compel to adopt disks with relatively large diameters. This would mean that the volumes of the cartridge valves cannot be limited or contained as wanted. The present invention aims to solve these problems and to provide mixing valves with a flow control unit, that is to say two disks in ceramic or similar materials which, thanks to particular and original arrangement and shape of the outlet hole or opening, have improved flow and mixing performances. Such a scope is achieved by a water flow control unit in mixing valves according to the characterizing part of claim 1. The use of disks which comply with the invention enables advantage to be taken of spaces which make use of the entire available surface and to therefore reach the requested flow even with disks of smaller diameter, which clearly, allows for an advantageous reduction in the volumes and dimensions or the valves which incorporate said disks. The invention also allows for the reduction of the movement angle of the upper disk on top of the lower disk, keeping the correct mixing conditions and retaining a satisfactory so called comfort angle due to a reduction of the water dividing partition cusp between the holes or openings of the fixed disk. Further characteristics and advantages of the invention will appear clearer following the description given below with references being made to the attached drawings in which: Figure 1 is an axial section of a mixing valve incorporating disks of ceramic or similar materials in accordance with the invention; Figure 2 and 3 respectively show the lower and upper surface of the fixed disk; Figures 4 and 5 respectively are section views of the fixed disk on the lines IV-IV and V-V in figure 3; Figures 6 and 7 respectively show the lower and upper surfaces of the movable disk; Figure 8 is a section on the lines VIII-VIII in figure 7; Figures 9, 10, 11 and 12 are different section views of the movable disk on top of the fixed one for the closing and flow conditions for only hot water, only cold water and mixed water; Figure 13 is an underneath view of the fixed disk; Figure 14 is an underneath view of the valve in figure 1; and Figures 15, 16, 17, 18 are different section views of the gasket placed between the bottom of the body and the fixed disk. The cartridge body (10) of the valve is indicated in figure 1 and encloses a lower fixed disk (11) which is sealed onto the bottom (10a) of the body, and a moving disk (12) which rests and is movable, both radially and in rotation, on the fixed disk (11). The upper movable disk (12) is operated, for example, by a control lever (13) indirectly joined to the same disk by a disk-cover (14) to which it is hooked. The fixed disk (11) has two water inlet holes or openings (15,16) designed to join corresponding (not represented) cold and hot water conduits and an opening (17) to let out hot, cold or mixed water towards a tap. The movable disk (12) has in turn a mixing chamber (18) which is open on the side near to the fixed disk (11) and closed at the top by the disk cover (14). The mixing chamber, depending on the position of the movable disk on top of the fixed one, can close the water inlet holes or allow a part or the entire of one or both water inlet holes to communicate with the outlet hole (17) so as to control the outflow of hot, cold or mixed water. According to the invention, the two water inlet holes or openings (15,16) of the fixed disk (11) substantially have a uniform width symmetrically about a water dividing partition (19) placed in a radial plane, into one half of the disk. The said water inlet holes or openings (15,16) angularly extend from the water dividing partition (19) in opposite directions, both through a 90° arc and with parallel sides. The water dividing partition (19) tapers off from the bottom of the fixed disk (11) towards the top to form a cusp (19a) which reduces the space between the two water inlet holes and forms the so-called comfort angle. The water outlet hole or opening (17) of the fixed disk (11) has an elliptic shape (fig. 3), with the centre line passing through the above mentioned water dividing cusp (19a) and with a focus coinciding with the centre of the disk (11) and the other focus in the half of the disk opposite into which the water inlet holes or openings (15,16) are cut. Part of the water outlet hole (17) is therefore placed between the two water inlet holes or openings (15,16) and is delimited by a partition (20). The remaining part of the outlet hole extends away from said openings but still in a centre line position. The partition (20) between the water outlet hole and the water inlet holes also tapers off towards the movable disk (12), with a bevel (20a) at least on the side of the water outlet hole. A single shaped gasket is fitted on the lower surface of the fixed disk (11), passing round and enclosing all the holes and openings (15,16,17) isolating one from the other. This gasket (21) can correspond to one of the cutaway views illustrated in figures 15 to 18 of the drawing. The mixing chamber (18) in the movable disk (12) has a key-hole shape which is defined by a circular part (18a) which has a smaller radius than the minimum radius of the water inlet holes (15,16) and is off-centre to the geometrical centre of the disk, and a polygonal part (18b). The opposite sides of said mixing chamber widen towards the top, that is to say towards the disk-cover (14). Figures 9 to 12 illustrate various interaction positions between the two overlapping disks, where the overlapping of the mixing chamber (18) with the water inlet and outlet holes (15,16,17), depends on the position of the movable disk (12) on top of the fixed one (11) so as to achieve the complete closure of the valve (fig. 9); the flow of only hot water (fig. 10); the flow of only cold water (fig. 11); and the flow of mixed hot and cold water. For the positionings which allow the water to flow, the circular part (13a) of the mixing chamber (18) moves over the water inlet holes whereas the polygonal part (18b) remains over the water outlet hole (17). For the correct positioning of the disks (11,12) inside the cartridge type body (10), the fixed disk (11) has some nonsymmetrical grooves (11a) designed to engage with said cartridge type body, whereas the movable disk (12) has some symmetrical grooves (12a) interagent with the disk cover (14). A limit stop (10a') will be placed inside the cartridge type body so as to control the direction of the disk-cover (14) and therefore the direction of the movable disk (12) for the valve closure position. Some discharge outlets (22), (as shown in figs. 1 and 14) are cut into the bottom of the cartridge type body (10) between the feet (where present) which are connected to the hot and cold water conduits so as to permit the flow of the water and not create blockages which limit the flow capacity allowed by the disks (11,12).

Claims: A water flow control unit in mixing valves for hot and cold water which comprises, inside a cartridge type body, two overlapping disks (11,12), one of which is fixed and the other is movable on top of the fixed one through an operating lever (13), and wherein: the fixed disk (11) has two separate water inlet holes or openings (15,16) for hot and cold water and an outlet hole or opening (17) for hot, cold or mixed water; the movable disk (12) has a mixing chamber (18) designed to connect one or both the water inlet holes or openings (15,16) with the outlet hole (17); said mixing chamber (18) is open on the side of the fixed disk (17) and closed at the top by a disk-cover (14) to which the operating lever (13) is connected; said two water inlet holes or openings (15,16) are substantially of uniform width and are cut into one half of the fixed disk symmetrically with respect to a water dividing partition (19) having a radial orientation; the mixing chamber (18) of the movable disk (12) is defined by a circular part (18a) off centre from the middle of the movable disk (12) and a communicating polygonal part (18b), said circular part (18a) having a smaller radius than the inside radius of the inlet holes or openings (15,16), and the outlet hole or opening (17) of the fixed disk (11) lies at least partially under said mixing chamber (18) of the movable disk (12), the centre line of said outlet hole or opening (17) passing through the water dividing partition (19) between the said inlet holes or openings (15,16), characterized in that said outlet hole or opening (17) has an elliptic shape with one focus in the centre of the fixed disk (11) and the other focus on the other half of the same disk with respect to the one half where inlet holes or opening (15,16) are cut. A unit according to claim 1, characterized in that said water dividing partition (19) between the said inlet holes or openings (15,16) tapers off to form a cusp (19a) on the surface of the fixed disk (11) which is in contact with the movable disk (12). A unit according to claims 1 and 2, characterized in that the outlet hole or opening (17) is separated from the inlet holes or openings (15,16) by a partition (20) which tapers off from the bottom surface towards the top of the fixed disk (11), at least on the side of the inlet holes or openings (15,16). A unit according to the preceding claims, characterized in that the opposite sides of the mixing chamber (18) are bevelled towards the disk-cover (14), and the circular part (18a) of said mixing chamber (18) is turned and moves over the inlet holes or openings (15,16). A unit according to the preceding claims, characterized in that the fixed disk (11) is splined into the cartridge body (10) by nonsymmetrical grooves (11a) and the movable disk (12) is splined to the disk-cover (14) by symmetrical grooves (12a), and additional discharge outlets (22) are cut at the bottom (10a) of said body (10) so as to increase the flow passage section for the water.

Inventors: ORLANDI ALESSIO, ORLANDI, ALESSIO
Applicants: GALATRON SRL, GALATRON S.R.L.
Application year: 1990
Main classification: F16K11
IPC codes: F16K11