Pair of cooperating disks to control the delivery of liquid in so-called screw type valves

Abstract: The invention relates to a pair of overlapping ceramic disks for the opening and closing of screw type valves, where there is a fixed disk (11) with lateral slots inside the valve body and another disk (12) which rests on top of the fixed one (11) and where the fixed disk (11;31) has at least one segment like slot (11a;31a) closed at the perimeter and the movable disk (12;32) has at least one lateral opening (12;32a) which is open both at the bottom towards the fixed disk and radially towards the lateral slots (13a) of the valve body, and closed at the top by a spoked surface so as to improve the water flow conditions.

Description: The present invention relates to sealing and control means for the delivery of liquid in valves for sanitary systems, especially in screw type valves with disks in ceramic or similar materials. Valves of this type are known, for example, from documents US-A-4, 821.765 and GB-A-2, 173,577. These documents disclose a removable cartridge type valve which has a valve body having lateral slots, a control rod having a handle, a pair of overlapping disks positioned in the valve body for regulating fluid flow through the valve in response to rotation of one disk over the other disk. In fact, a first of said disks is fixed inside the valve body and has two segment like slots,the second of said disks is movable and rotates onto said first disk and has lateral openings which are open both at the bottom towards the fixed disk and radiaily towards the lateral slots of the valve body. In the embodiment described in US-A-4.821,765, the control rod is directly connected to the movable disk, while in the embodiment dislosed in GB-A-2,173,577, the control rod is connected to the movable disk through an intermediate entrainer which has a central tab only that can be inserted into a recess arranged diametrically with respect to the top of the movable disk. In both documents, the lateral openings of the movable disk are L-shaped with a curved surface at the corner of the two square sides of the "L", which negatively affect the rate of flow and keeps the noise level high. Moreover, although an entrainer between the control rod and the movable disk is envisaged, as in GB-A-217,577,there are no seals between the elements so coupled. On the basis of this preliminary statement, the object of this invention is to provide a so-called screw-type valve incorporating a pair of disks made of ceramics or other similar material, which have a new configuration at least as regards the lateral openings of the movable disk, to improve fluid outflow, reduce noise level and increase the rate of flow with respect to disks of the same dimensions. The adoption of these disks also makes it possibile to locate a seal above moving disk, at a certain distance in a point where the working temperature is reduced by the entrainer connected to the movable disk. Moreover, for connection to the movable disk, the entrainer has two lateral tabs in addition to a central tab, which engage the movable disk, said lateral tabs having a curved head surface in continuation to a top surface of the corresponding openings of the movable disk. In addition the movable disk, or more precisely openings thereof,can be fitted with notches which interrupt the flow and reduce the noise of the delivered liquid without loss of the flow capacity. To this purpose, the present invention relates to a valve according to the preamble of claim 1 (as is e.g.Known from GB-A-2, 173,577) and characterized in that: each lateral opening of the movable disk is defined at the top by a curved or parabolic surface rising from the base approximately at the centre of the movable disk up to the periphery of the same disk; a seal is fitted between the entrainer and the control rod; and entrainer has two lateral tabs and a central tab which engage the movable disk, at least one of said lateral tabs having a curved head surface in continuation to the top surface of said lateral opening. An example of practical realization of the invention will be described below in more detail, with references being made to the attached drawing in which: Figure 1 is a partial axial section view of the screw type valve with a 90° rotation opening of closing defined by internal limiting devices; Figure 2 is a sectional view of the movable disk on the lines II-II in figure 1; Figure 3 is a perspective view of the disks and the entrainer; Figure 4 is a part of the valve with notches which interrupt the flow; Figure 5 is a pair of disks for screw type valves with a 180° opening and closing rotation; and Figure 6 is a screw type valve like the one in figure 1, but with rotation limiting devices on the outside of its body. Said drawing shows the two overlapping disks (11,12) which are incorporated inside a valve body (13 which is designed to be coordinated for screwing, and has peripheral seals (13b) interpositioned in taps for sanitary systems, in line with a water delivery conduit. The valve body (13 has flow outlet radial slots (13a), and the disks (11,12) are at the same level of said slots, and comprise a lower fixed disk (11) and an upper one (12) which rotates on top of the fixed one. In more detail, the fixed disk is splined to a disk-holder ring (14) which is hooked to the lower part of the valve body (13). This ring has notched tabs (14a) engaged with shoulders cut into said valve body. The fixed disk (11) rests on the ring (14) with the interposition of a seal (14b); a basic annular seal (15) for the sealing of the water inlet is fitted to the bottom of the ring (14). The upper movable disk (12) is splined to art entrainer (16) which is, in turn, splined to the lower end of a control rod (17). The top of the control rod (17) is partially broached and equipped with a control handle (not shown). The entrainer (16) has two lateral tabs (16a) and a central tab (16b) which are all parallel to each other and designed to engage the movable disk (12) as in the drawing. In turn, the rod (17) has a lower placed tab (17a) engaged in a straight or crossed slot (17c) cut into the entrainer (16). Furthermore, the rod (17) is rotated inside the valve body (13) with the interposition of seals (18,18') and an anti-friction ring (19) all at different levels. A seal (20) can also be placed between the entrainer (16) and the control rod (17). This seal (20) is not in contact with the movable disk (12) and therefore works at a lower temperature than said disk. In a screw valve with a 90° opening and closing rotation (figs. 1 and 3) the fixed disk has two segment like slots (11a), closed at the perimeter whereas the movable disk (12) has two openings (12a) which are open both at the bottom towards the fixed disk (11) and radially towards the slots (13a) of the valve body (13), but closed at the top towards the entrainer (16). The angular amplitude of the openings (12a) of the movable disk (12) is similar to the amplitude of the slots (11a) of the fixed disk (11), but nevertheless smaller than the spaces between said slots (11a) of the fixed disk. Seen from below, the movable disk (12) has an "X" shape which is made up of two openings (12a) which alternate with two solid parts, lateral flattenings (12c) being cut in correspondance of said openings. In each case, the top of both openings (12a) are defined by a spherical or parabolic surface which rises from the bottom, more or less in the centre of the disk, towards the perimeter where it joins the surface of the entrainer above (16) which also has curved lateral tabs (16a). The surface more or less reaches the top of the radial slots (13a) of the body (13). The rod has at least one lateral shoulder (21) which operates together with a blocking notch (22) integral with the body so as to limit the rotation of the rod (17) to 90° and so as to position the openings of the movable disk in correspondence with or away from the ones of the fixed disk. Tests have proven that this configuration of the disks, especially the movable one (12), allows an improved flow of liquid and a greater flow capacity with respect to known realizations under the same conditions. In a screw type valve with a 180° opening and closing rotation as in Fig. 5 of the drawing, the fixed disk (31) has only one semi-circular slot (31a) and the movable disk (32) only one lateral opening (32a) with a spoked top and joint to a corresponding lateral tab of the entainer in a similar way to that which has been described above. Some appropriate parts will be fitted on the control rod so as to limit the rotation of the movable disk (32). In both cases, the parts which will limit the rotation of the control rod (17) can be fitted onto the outside of the body (13), at the top. These parts therefore comprise (Fig. 6) two shoulders (41) which are angularly spaced and cut into the top of the body (13) and a ring (42) splined and rotating with the rod (17), having at least one radial notch (43) designed to alternately interact with said shoulders and be axially stopped by a Seger or similar on the rod itself. The ring can be splined into two different phase angle positions for the opening with a right or left rotation of the rod. The positions are clearly marked (43a) on the notch (43) and by he arrows "L" and "R" on the rod. Finally, notches (23) of graduated length can be cut into or fitted to the openings (12a,32a) of the movable disk (12,32) so as to interrupt the flow of liquids and reduce the noise of the system (Fig. 4).

Claims: A valve comprising a valve body (13) having lateral slots (13a), a control rod (17) having a handle, a pair of overlapping disks (11, 12;31 ,32) in ceramic or similar materials for the opening and closing the screw type valve, and where a first of said disks (11,31) is fixed inside the valve body (13) and has at least one segment like slot (11a, 31a) closed at the perimeter, the second of said disks (12,32) is movable and rests and rotates onto said first disk and has at least one lateral opening (12a, 32a) which is open both at the bottom towards the fixed disk and radiaily towards the lateral slots (13a) of the valve body, and the second movable disk is connected to said control rod (17) through an intermediate entrainer (16), characterized in that: said lateral opening is defined at the top by a curved or parabolic surface (12b) rising from the base approximately at the centre of the movable disk up to the periphery of the same disk; a seal (20) is fitted between the entrainer (10) and the control rod (17); and said entrainer (16) has two lateral tabs (16a) and a central tab (16b) which engage the movable disk (12;32), at least one of said lateral tabs (16a) having a curved head surface in continuation to the top surface of the corresponding opening (12a, 32a) of the movable disk (12,32). A valve according to claim 1, characterized in that the first, fixed disk (11) has two segment slots (11a) closed at the perimeter and in that the second, movable disk (12) has two opening (12a) which are open both at the bottom towards the fixed disk and radially towards the lateral slots (13a) of the valve body and closed at the top by the curved surface (12b) which rises from the base approximately at the centre of the movable disk. A valve according to claim 2, characterized in that the movable disk (12), viewed from underneath, has an "X" shape with the two openings (12a) alternating with two solid parts, and lateral flattenings (12c) cut in correspondence to said openings.

Inventors: ORLANDI ALESSIO, ORLANDI, ALESSIO
Applicants: GALATRON SRL, GALATRON S.R.L.
Application year: 1990
Main classification: F16K3
IPC codes: F16K3