Abstract:
A distribution member for mixing cocks, having the form of a lamellar skirt of an elastically yielding material cooperating with fluid passage ports, and having a backing of a compressed resilient material which exerts an elastical backing action substantially onto the whole surface of the operatively active portion of the skirt.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a distribution member for mixer cocks, flow dividers and the like, whose working part, designed to co-operate with fluid passage ports, is in the form of a lamellar skirt. 
     In certain types of hydraulic accessory, such as single control mixer cocks, flow dividers and the like, a rotatable and in some cases axially movable plug co-operates with fluid passage ports for adjusting the fluid flow proportions through the different ports. This is obtained by forming in the plug suitably shaped recesses which in determined positions expose the ports so enabling fluid to pass. The seal between the plug and ports must be made by gaskets of a certain complexity. Moreover the fluid passages, even when the ports are completely open, are throttled by the limited cross-section of the recesses formed in the plug, and this leads to flow rate limitation, pressure drops and noise. Finally, serious disadvantages can arise when small foreign bodies, such as particles of sand or calcareous deposits, become inserted between the plug and fluid passage ports, giving rise both to a momentary seal deficiency and damage to the parts. 
     BRIEF SUMMARY OF THE INVENTION 
     The object of the invention is to configure the distributor member, forming part of the plug or fixed to it and designed to co-operate with the fluid passage ports so as to partially or totally open and close them, in such a manner that the seal is effectively made by the distributor member itself without the aid of gaskets, and moreover this member is able to yield elastically in the presence of foreign bodies, so enabling their evacuation without causing or producing damage, and that a considerable passage cross-section for the fluid is ensured by that part of the distributor member opposite the co-operating ports, so avoiding resistance to movement and noise. To this end, according to the invention, in a distributor member for mixer taps, flow dividers or the like, designed to co-operate with fluid passage ports so as to partially or totally open them and close them, at least that part of said member which moves over the ports comprises an interrupted lamellar skirt of elastically yieldable material, connected at least one extremity to a support and control member, and between the lamellar skirt and a stem, passing within said skirt, of the respective support and control member, a compressed resilient material is arranged, to exert an elastical backing action substantially on the whole surface at least of the operatively active portion of the skirt. 
     The necessity, taken into account by the present invention, for the resiliently backing action to be exerted substantially on the whole active surface of the skirt, originates from the deformability of the skirt, which deformability renders inapplicable the known arrangements for pushing a deformable jacket against apertures, said arrangements contemplating the interposition of a certain number of resilient rings which exert a localized pushing action whose utilization in view of obtaining the sealing effect of the jacket with respect to the apertures requires a relatively high stiffness of the jacket itself. 
     Also, according to this invention the distributing member is preferably connected to the respective support and control member by means of a coupling apt to assume various positions, which allows to manufacture from standardized parts mixing valves in which the arrangement of the control members with respect to the apertures is realized in various manners. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention will be explained better in the following description of an illustrative and not limitative embodiment shown diagrammatically, together with some variants, in the accompanying drawing, wherein: 
     FIG. 1 is an axial and diametral sectional elevation of a single-control mixing valve, the section being made through the inlet ducts for the liquids to be mixed, 
     FIG. 2 is a similar sectional elevation made through the delivery duct, with the control member of the valve in a different position, and 
     FIGS. from 3 to 7 are enlarged cross-sectional views of various possible forms of the lamellar skirt and its resilient backing element. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The mixing valve shown in FIGS. 1 and 2 comprises a body 1 in which a plug 2 is mounted which is axially movable and rotatable and whose rotation and axial translation movements are controlled by means of a lever 3 pivoted in a rotatable but axially non-movable hood 4 mounted on the body 1 by means of a ring 5. The plug 2 is provided with a gasket 6 arranged to cooperate with a seating 30, disposed in the body 1, in order to intercept the fluid and regulate its flow. 
     The body 1 is formed with an outlet duct 8 which communicates with the inner chamber 7 of the body 1 when the gasket 6 is in its opening position. The body is also provided with inlet ducts 9 and 10 which communicate through openings 11 and 12 with the inner chamber 7 under the control of the distributing member shaped as an interrupted lamellar skirt 13 extending in the region corresponding to the apertures 11 and 12 by an angle which is sufficient to allow, through rotation of the plug 2, the opening of one aperture and the closing of the other, or vice versa, as well as all the intermediate conditions of regulation. Said interrupted lamellar skirt is made of an elastically yielding material, such as a suitable synthetic material, preferably of the type which is subject to cold flow, and has such dimensions as to remain elastically pressed against the inner cavity of the body 1, into which open the apertures 11 and 12, such as to establish a seal around said apertures without requiring the use of gaskets. The skirt 13 is relatively thin and has a limited stiffness in order to adapt itself in the best possible way to the surface with which it has to establish a sealing, but in consequence of this the skirt is not in a position to maintain the sealing effect against the pressure exerted by the incoming flow. In order to maintain the sealing effect in spite of that, between the skirt 13 and the portion of plug 2 which passes in its interior there is inserted a compressed resilient material 25 which resiliently backs the skirt 13 and holds it pressed against the inner cavity of the body 1 in the region of the apertures 11 and 12. The resilient material 25 is disposed in such a way as to exert its action onto the inner surface of the skirt 13 substantially along the whole portion of said surface to which corresponds an outer surface which is active in the sealing function. To this end, the resilient filling material 25 may fill uniformly the space between the skirt 13, 13&#39;, 13&#34; and the plug 2, 2&#39;, 2&#34;, as shown in the FIGS. from 3 to 5, or it may be provided with outer recesses 26 (FIG. 6) and/or inner recesses 27 (FIG. 7), said recesses having the function of increasing the yielding capacity of the material 25, 25&#39;, 25&#34; respectively but having sufficiently reduced dimensions for not being prejudicial to the action by which the skirt 13, 13&#34; is pressed towards the outside. 
     In order to hold in place the material 25, 25&#34;, the skirt 13&#39;, 13&#34; may be formed with small flanges 28, 28&#39; oriented towards the plug 2, 2&#39; and eventually engaged in it, as shown in FIGS. 3, 4 and 7, or the plug 2&#34; may be provided with tabs 29 for the same purpose, as shown in FIGS. 5 and 6. 
     For the connection between the skirt 13 and the plug 2, the skirt is provided with a collar 17 intended to enclose a seat 15 of the plug. In order to ensure joint rotation of the skirt 13 and the plug 2 it is possible to utilize a projection of the seat 15 of the plug 2, which projection engages an interruption of the collar 17, but preferably the collar 17 and the seat 15 have a toothed or prismatical configuration, so as to allow the skirt 13 to be keyed in various positions, which permits the standardization of parts of the valves which have a different relative arrangement of the control members and the inlet ports. 
     In case the flanges 28&#39; or the tabs 29 are themselves in a position to ensure joint rotation engagement between the plug 2&#39;, 2&#34; and the skirt 13, 13&#34;, there is of course no need to provide other arrangements for the same purpose. 
     The outer surface of the skirt 13&#39; may advantageously be lightened, in its non operative region, by means of recesses, as shown in FIG. 3, in order to reduce the contact surface, where such surface is not necessary, and consequently reduce the friction during manipulation. 
     The resilient material may be, for example, soft rubber, soft synthetic material or a synthetic material softened by means of a spongy or cellular structure. It may be utilized under the form of a molded piece having the required shape or a piece of a flat laminate cut to the desired shape and wound in the space between the skirt 13 and the plug 2. 
     Obviously, the embodiments described herein and represented in the drawings are to be considered as illustrative only and not restrictive, as the invention is susceptible to receive somewhat different forms according to the requirements of the various applications thereof.