Abstract:
A stem valve stopper that has a shell ( 1 ) intended to be mounted to a faucet (K). An operating stem ( 8 ) is mounted for rotation but is axially fixed in the stopper shell ( 1 ) and has a lower end that acts as a valve seat surface ( 12 ). The stem  8  has an interior section ( 7 ) that is threadably engaged with a mobile fitting ( 6 ) that is mounted in the shell so that it can be moved axially but cannot be turned or rotated inside the stopper shell. The mobile fitting ( 6 ) has an annular lower end surrounding a valve seat ( 12 ). A valve sealing member ( 17 ) made from elastomeric material is mounted in the lower end of stopper shell ( 1 ) and is spring biased downstream toward the valve seat ( 12 ). The mobile fitting ( 6 ) can be operated to push the sealing member ( 17 ) upstream away from valve seat surface ( 12 ) and provide flow about the valve seat ( 12 ). The valve seat is made from elastomeric material and preferably inside its retaining regions has a hollow space so that, in the closed mode, it is dilated by the pressure of the water to press against the valve seat surface ( 12 ).

Description:
TECHNICAL FIELD 
     This invention relates to a stopper of the rotating screw type, intended to be applied to a cock, tap or faucet to adjust the flow of water between an intake passage and an outlet passage. 
     BACKGROUND OF THE INVENTION 
     Rotating screw stoppers have long been used to control the flow through a tap or faucet. The screw has an exterior end mounted to a handle. The screw, commonly in the form of a stem or arbor, is threadably engaged to a housing and mounting a mobile valve seal or washer at the interior end. 
     As the screw valve is tightened, the washer is compressed against a valve seat. However, the washer by being rotated as it compressed against the valve seat until the stem was fully tightened unduly wore both the washer and the valve seat. While the washer could be replaced, the valve seat could not. Furthermore, the stem rose out of the housing as the valve was opened which many users deemed undesirable. Non-rising stem valves have been developed that use shearing action of a valve seal. However, compressive valves are often still desirable due to the better sealing seating available through compressive action. More non-rising stem valves have been developed that continue to use compressive action of the seal against a fixed valve seat. 
     A non-rising stem stopper essentially compresses a shell, intended to be affixed securely to the body of a faucet device. A mobile fitting is mounted in an axially movable manner and in a nonrotatable manner inside the shell of the stopper and bearing a valve seal. An operating stem is mounted for rotation and fixed in an axial direction in the shell o the stopper. The stem has one end inside the shell, linked by a screw threading to the mobile fitting, and an outer end that protrudes form the shell of the stopper and constructed to mount an operating handle. Rotation of the handle causes axial shifting of the mobile fitting and the valve seal which, cooperating in a timely fashion with a valve seat placed between the intake passage and the outlet passage of the body of a faucet valve brings about the desired adjustment of the water flow. 
     Traditionally, the valve seal, supported by the mobile fitting, was made up of a packing disc consisting of elastomeric material. The mount of the inlet passage is formed in the body of a faucet, itself as a valve seat that cooperates with the packing disc to adjust the flow. An example of this traditional arrangement is provided in document DE-U-94 18 554. 
     With this arrangement, a sealing washer made of elastomeric material was subject to deterioration. After deterioration, the washer can be easily removed by dismantling the shell of the stopper form the body of the set of cocks, taps and valves. Furthermore, the repair was inexpensive. A simple washer with a central hole was attached via a bolt. 
     However, the valve seat that cooperates with this washer is also subjected to deterioration. Due to the valve seat being a part of the body of a cock, tap or valve, it can be restored only by working on it with a suitable manual milling machine. Such a repair is not an easy operation nor are the results always satisfactory and the repair cannot be repeated more than several times. 
     An attempt was therefore undertaken to make this valve seat on a separate member that is screwed into the body of the faucet and that can be extracted so that it may be repaired or replaced. Such a modification results in an excessive increase in the cost of the faucet. 
     Furthermore, the operations involved in disassembly and reassembling the applied valve seat are not easy and require special tools. 
     An attempt was made to remedy this inconvenience, for example, as disclosed in document EP-B-O 606 419. In this disclosure, the valve seal is a rigid element forming a part of the mobile fitting of the stopper. A special packing made of elastomeric material installed in the shell itself fits tightly against the mount of the intake passage presented by the body of a faucet and which, will cooperate with the rigid vale seal presented by the mobile fitting of the stopper. The body of the faucet is thus protected against any deterioration; but the special necessary packing must have a complex configuration and is therefore expensive. The shell of the stopper also requires relatively expensive processing to manufacture a seat intended to receive such a packing. 
     According to International Patent Application WO 93/24774, the use of a packing with a complex shape was avoided by installing a first ferrule that forms a ring-shaped shoulder in the end of the body of the stopper with the stop bolt. A second ferrule is installed inside the first one that received a static packing intended to provide a seal against the mouth of the inlet passage of the faucet body. The interior end of the second ferrule holds an elastomeric retaining sealing member by a spring toward the shoulder of the first ferrule. The mobile fitting of the stopper moves axially onto the sealing element for shutting off flows and rises away from the sealing element to an open position. A disadvantage of this arrangement is that two ferrules must be used. Besides the added costs and complexity of two ferrules, the presence of two ferrules adds thickness inside the shell of the stopper. This increased thickness limits the diameter of the elastomeric sealing member and the passage therethrough which in turn restricts the maximum flow volume of the stopper under maximum opening conditions. 
     Furthermore, in the known stopper constructions, the pressure of the water works on the mobile fitting over a large cross section, giving rise to a relatively powerful force that must be overcome by working the stopper. Furthermore, as the elastomeric sealing member wears out or is crushed, the mobile fitting axially advance an increased distance position to provide the seal in the closed position in turn which entails inconveniences and interferes with the service life of the packing. In addition, the known valve stopper has static packings placed between the shell of the stopper which can yield only to a very limited degree. The distance between the region in which the valve stopper shell is screwed onto the faucet body and the surface of the body against which said static packing must establish a successful seal becomes critical. In some cases, manufacturing here requires compliance with excessively restricted tolerances, which again causes higher costs and gives rise to the possibility of inconveniences due to the heat expansion of the parts. 
     What is needed is a valve stopper with a non-rising stem so as to be sealed against the body of the faucet with the use of a simply shaped packing and without any need for expensive work on the shell of the stopper. It is further needed to have a packing and that can be easily accessed and replaced when it has worn out or is broken. What is also desired is to increase maximum flow rates of a valve stopper for a given outer dimension and to decrease the total force due to the water pressure against the mobile fitting to reduce the force needed to operate the valve stem. It is also desired to incorporate a device to reduce the noise level connected with any severely restricted flow of water. 
     It is further desirable to construct such a stopper that may have increased manufacturing tolerances as to the distance between the region in which the stopper is installed in the faucet body and the surface of the body where the seal must be established with the packing seal. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the invention, a valve stopper includes a shell constructed to be sealingly securable to a faucet body. An operating arbor is mounted rotatably in the shell of the stopper. An outer end of the arbor protrudes from the shell of the stopper and constructed to mount an operating handle. The arbor has an inner end forming a valve seat surface. Preferably the arbor is mounted only for rotatable motion and is fixed in an axial direction in the shell. 
     A mobile fitting is mounted in an axially movable fashion inside the shell of the stopper and operably connected with the arbor to move axially as the arbor rotates. The mobile fitting has the shape of an annular jacket surrounding the arbor with radial ports therethrough and can move upstream from the valve seat surface. The annular mobile fitting is preferably non-rotatably fixed with respect to the shell and threadably engaged to the arbor for only axial movement in the shell as the arbor is rotated. 
     A first annular sealing member cooperates with the valve seat surface on the arbor at one axial end to shut off the valve stopper and constructed to abut against the annular mobile fitting. As the mobile fitting axially moves in the shell upstream toward an open position, the sealing member is moved away from the arbor and unseated from the valve seat surface. The sealing member is resiliently biased to move downstream toward and abut the valve seat surface as the mobile fitting is axially moved toward a closed position. 
     Preferably the first annular sealing member is housed in a single ferrule. The ferrule has a support seat for seating a biased sealing element and a second seat for seating a static sealing element to provide a sealing connection about a mouth of a passage in the body of the faucet to the inlet in the valve stopper. 
     In one embodiment, the static sealing element is provided by a second annular sealing member biased in a direction opposite to the bias of the first annular sealing member. Both the first and second annular sealing member are received directly in one end of the shell of the stopper and sealingly abut an inner surface of said shell. Each sealing member is preferably made from elastomeric material biased by a spring. Preferably a single biasing element applies the resilient bias to both the first and second sealing members in opposite directions. In another embodiment, the sealing members are made from rigid material and biased by a spring and provided with a retaining packing. In another embodiment, the sealing members are made from elastomeric material and biased by their own resilient elasticity. 
     It is desirable that the radial ports in the mobile fitting have respective narrowed passage sections which receive flow under conditions of severe choking. The narrow passages are formed by one of protrusions situated in said radial ports, millings, and small holes in a wall of the mobile fitting. 
     In accordance with another aspect of the invention, the operating arbor is mounted rotatably in the shell of the stopper. The mobile fitting is mounted in an axially movable fashion inside the shell of the stopper and operably connected with the arbor to move axially as the arbor rotates. An interior valve seating surface is axially affixed in the interior of the shell. The mobile fitting has the shape of an annular jacket surrounding the interior valve seat surface with radial passages therethrough. The annular sealing member is operably connected to an inlet for allowing flow therethrough and has its downstream end sealingly abutted to the valve seating surface. The annular mobile fitting can move the sealing member upstream away from the valve seating surface as it is axially moved to an open position. The sealing member is resiliently biased to move downstream toward and abut the interior valve seat surface as said mobile fitting is axially moved toward a closed position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Reference now is made to the accompanying drawings in which: 
     FIG. 1 is a side elevational and segmented view of a valve stopper according to a first embodiment of the invention in the closed position; 
     FIG. 2 is a view similar to FIG. 1 illustrating the valve stopper in the open position; 
     FIG. 3 shows an enlarged detail looking along lines  3 — 3  in FIG. 2; 
     FIG. 4 is a view similar to FIG. 1 illustrating a second embodiment in the closed position; 
     FIG. 5 is a view similar to FIG. 4 illustrating the second embodiment of the invention in the open position; 
     FIG. 6 is a view similar to FIG. 1 illustrating a third embodiment in the closed position; 
     FIG. 7 is a view similar to FIG. 6 illustrating the third embodiment in the open position; and 
     FIG. 8 is a cross sectional view taken along lines  8 — 8  in FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIG. 1, a valve stopper has a shell  1  provided with an exterior screw threading  2  for its connection to the body of a faucet (of which the drawing for reasons of clarity only shows the region presenting mouth K of passage P for water intake). The stopper also has peripheral openings  3  for the discharge of water, and a packing  4  to create a tight hold with the body of the faucet. The shell  1  houses a mobile fitting  6  mounted via a splined connection  11  so as to be non-rotatably movable in the axial direction. A packing  5  establishes the seal between shell  1  and mobile fitting  6 . In shell  1 , there is also housed an operating stem or arbor  9 . The stem  9  is mounted for rotation but is affixed in the axial direction. Stem  9  has a threaded internal section  7  that is screwed into a corresponding screw threading  24  of mobile fitting  6  and has an outer end  8  that protrudes from shell  1  and is so arranged as to receive an operating handle (not shown). All of the parts described to far are commonly found in a variety of stem valves and are well known. When operating stem  9  is rotated by means of a handle, the mobile fitting  6  is shifted axially up and down. 
     In contrast to known designs, stem  9  extends into the inside of the stopper beyond threaded part  7  to form a valve seat  12 , and a sealing gasket  13  establishes its seal with respect to mobile fitting  6 . In turn, mobile fitting  6  has the shape of an annular jacket and extends around piston  12 , presenting radial delivery openings  14 . 
     As illustrated in FIGS. 1 and 2, a ferrule  10  made of rigid material is installed in the end of body  1 , which is opposite stem  9 , there is installed in a fixed manner. The ferrule has a substantially cylindrical downstream end facing toward the inside of the stopper and an outside flange  15  that forms a seat for a static packing  16  that is intended to provide a seal against mouth or nozzle K of passage P for the intake of water from the faucet body. A passage  25  passes through ferrule  10 . 
     An elastomeric annular sealing member  17  is mounted for axial movement in ferrule  10  and which is resiliently biased toward valve seat  12  by a spring  18  which rests against flange  15  of ferrule  10 . The stacked thickness of body  1  and of the single ferrule  10  limits the diameter of annular sealing member  17 . The annular sealing member  17  can be sized to span the entire inner diameter of the ferrule  10  and have a sized aperture  26  outside will permit a strong flow volume (in the maximum open position as described later). 
     When the mobile fitting  6  is in the position shown in FIG. 1, that is, in the closed position that is most distant from inlet  25 , lifted off of sealing member  17 , and lifted above valve seat  12 ; sealing member  17  is biased by spring  18  and will sealingly abut against valve seat  12 . The stopper is therefore in the shut-off or closed position. In this position, the water pressure, acts on the cross-sectional exposed area of sealing member  17  which may exceed the exposed surface area of valve seat  12  thus contributing to maintaining the closure with a force in proportion to the water pressure at passage P. 
     The valve stem  9 , as it rotates, can shift mobile fitting  6  toward sealing member  17  as shown in FIG.  2 . Consequently, the mobile fitting  6  will come to rest against the peripheral annular region of sealing member  17  and will push it away from valve seat surface  12 . The water comes from inlet passage P through mouth K which is sealed with packing  16 . The water then passes through the lower passage  25  in ferrule  10  and through the passage  26  in sealing member  17  and then between member  17  and valve seat  12 . The water flows through delivery openings  14  of mobile fitting  6  and finally comes out of shell  1  through its peripheral openings  3  and is passed back into the faucet body in order then to be delivered by it through a spout, showerhead or other nozzle device. The permitted flow volume naturally depends on the distance that the mobile fitting  6  has shifted sealing member  17  from valve seat  12 . The flow rate can be adjusted up to a predetermined maximum by rotation of stem  9 . 
     The operation of this stopper offers various advantages, in addition to its structural advantages. The fact that sealing member  17  is shifted during normal operation of the faucet and, hence, frequently, and provides dynamic movement rather than a mere static function thus preventing deposits of limestone between member  17  and its seat, ferrule  10  which can seriously impair successful operation of the valve. The fact that the mobile fitting when moved to press against the elastomeric member  17  is opening the stopper and not, as is customary, closing it is also advantageous. In this way, the stopper remains entirely protected against the possibility, which often happens in known stoppers, that the user might close the stopper with excessive force, which can damage the seals. Furthermore, the fact that valve seat surface  12  rotates with operating stem  9  means that it will periodically exert a polishing action on sealing member  17  further preventing the formation of limestone deposits and expelling any possible small, foreign bodies. 
     The described structure is particularly suitable for the introduction of very simple device that can reduce the flow noise which tends to be considerable under conditions of severe restriction which exist at the beginning of the opening and at the end of the closing action. Little teeth or protrusions  20  as clearly shown in FIG. 3 protrude on one side of the delivery openings  14  form narrow passages therebetween. Alternately grills situated in the delivery openings or from millings or small holes made in a wall of the mobile can suffice. Under conditions of severe choking, the flow must thus pass through these narrow passages, causing the flow to slow down and moderate its turbulence and hence its noise level. FIGS. 4 and 5 illustrate another embodiment that avoids the critical nature of the distance between the region in which the valve stopper is screwed into the body of the faucet and the mount surface K of the body of the faucet against which the packing seal must sealingly abut. In these figures and the following figures, the same parts or parts corresponding to those already described for the first embodiment have the same reference numbers and are not described any further. 
     In this embodiment the ferrule  10  is eliminated as in the first embodiment, and sealing member  17  is received in the end of the shell  1  of the stopper. For this reason, the sealing member  17  in the second embodiment may have an enlarged diameter than the sealing member  17  in the first embodiment, thus allowing an increased maximum flow. There is also provided a second sealing member  19 , arranged in an upside-down position with respect to the first sealing member  17  and which can advantageously be biased by the same spring  18  in an opposite direction from sealing member  17 . Sealing member  19  thus tends to bias itself out from body  1  of the stopper, and against the body of a faucet to provide a seal against mouth K about intake passage P. In this case, likewise, as in the case of member  17 , the seal is established both by the force of the spring  18  and by the pressure of the water, which acts on the internal surface of sealing member  19 . Therefore, the seal is established with a force that is in proportion to the water pressure and hence in a particularly secure fashion. 
     Because sealing member  19  can axially move in body  1  of the stopper, it can accommodate even major differences in distance D. which is effectively present between the region between shoulder S in which the stopper is screwed into the body of the faucet and valves and mouth surface K of the faucet body against which the seal must be established with member  19 . This feature also facilitates and allows the valve stopper according to the invention to replace preceding stoppers in faucets and valves in which the distance D can have some varying values. 
     It is also noted that the effect of the inevitable heat expansions of the parts, which in known design harms the performance of the static packing  16  arranged between the stopper and the faucet body. In this embodiment, the expansion provides an advantageous feature. The repeated expansion produces repeated small movements of sealing member  17  in body  1  of the stopper and thus, by virtue of this effect, also prevents the formation of harmful deposits of limestone. Furthermore, this embodiment allows the sealing members  17 , 19  to be easily exchanged when they are worn out or damaged by simply unthreading the stopper from body  1  of the stopper and replacing new collars without requiring the use of any tools. 
     A third embodiment is disclosed in FIGS. 6-8. In this embodiment the valve seat  12  is not part of the stem  9  but is a cap member  32  secured to the top end of ferrule  10 . It may be press fitted or attached via a bayonet or other secure fitting method about its periphery  33 . The valve seat  12  is secured in place via radially extending braces  34  extending from seat  12  to periphery  33 . Radial vents  35  surround seat  12  between braces  34  as shown in FIG.  8 . The mobile fitting  11  has circumferentially positioned fingers  36  extending through some of the vents  35 . Radial openings  14  are formed between the fingers  36 . The sealing member  17  in this embodiment is made from a rigid material such as ceramic and has a sealing gasket  38  about its periphery abutting the upper surface of ferrule  10 . 
     As shown in FIG. 6, when the mobile fitting  6  is lifted, the sealing member  17  is biased to seal against fixed valve seat  12 . As mobile fitting  6  is axially moved downward in the upstream direction, as shown in FIG. 7, the fingers  36  extend through some of the vents  35  and push the sealing member  17  away from fixed valve seat  12 . As sealing member  17  moves upstream and away, the water flow passes through vents  35  about valve seat  12  and out through openings  14  and outlets  3 . 
     The stem valve stopper according to the invention thus can attain all or a part of the above stated advantages without any significant increase in its production cost. In particular, the designer can in an optimum fashion adapt the features of the stopper to any special requirements associated with each particular application. 
     It must be understood that the invention is not restricted to the embodiments described and illustrated by way of example. Some modifications are within the reach of the technician in the field, especially as regards the structure of the sealing member where it can be pushed by its own elasticity. In this latter case, it is also possible to make two sealing members all in one integrated piece with a single intermediate region, for example, in the form of bellows, acting as elastic member for both. Arrangements intended to silence the flow of the stopper can also be varied and, where a second sealing member is used to work against a surface of the set of taps and valves, one may adopt arrangements to prevent the members  17  and  19  from coming out completely, except when they must be replaced. 
     Other variations are foreseen without departing from the spirit and scope of the invention as defined in the appended claims.