WO2008058320A1

WO2008058320A1 - Valve assembly

Info

Publication number: WO2008058320A1
Application number: PCT/AU2007/001732
Authority: WO
Inventors: Brian Ashford
Original assignee: Brian Ashford
Priority date: 2006-11-13
Filing date: 2007-11-12
Publication date: 2008-05-22
Also published as: AU2007321698A1

Abstract

A tap valve assembly is provided for regulating fluid flow. The assembly includes a spindle and complementally threaded spindle housing to allow axial displacement of the spindle when rotated within the spindle housing. The valve assembly may include at least one threaded axially adjustable insert which is screwed into a threaded opening of the spindle housing as well as upper and lower stops which are fitted to the spindle. Adjustment of the upper and lower limits of travel of the spindle is affected by screwing the insert up or down within the spindle housing. The spindle may be fitted with one or more spacer washers. The extent of vertical travel of the spindle is adjusted by adjusting the number of spacer washers on the shoulder, each washer typically representing a restriction of a one quarter turn. The spindle housing is positioned in a desired position in a tap body or faucet relative to a desired valve handle position using a locking ring which is screwed down over a complementally threaded spindle housing to lock the spindle housing in position.

Description

Valve assembly Field of the invention

The present invention relates to a valve assembly, and in particular to a valve assembly for use on a tap or faucet. Background of the invention

Fluid flows through valve assemblies are typically regulated by modifying the displacement of a valve from a valve seat. Common valve assemblies rely on the rotation of a threaded spindle shaft in a spindle housing to reversibly alter the position of the valve relative to the valve seat. When the valve head is in contact with the seat, the valve assembly is in the closed position, preventing the passage of fluid through the valve.

The successive rotation of the spindle shaft carried out by an operator turning a tap handle alters the displacement of the valve head from the valve seat, hence permitting an increasing fluid flow through the assembly up to the point at which the valve is fully open.

Common valve or stopcock assemblies require a number of successive full rotations of the spindle shaft to move the valve or stopcock between the fully open and fully closed position. Multiple full rotations of the spindle shaft may be undesirable or impossible in a number of situations e.g. in a hospital environment or in an aged care home, or may simply be inconvenient in a domestic environment.

One known solution in the art to some of the problems of conventional multi-turn valve assemblies is provided by ceramic disc tap assemblies. A limited degree of rotation of the spindle shaft by an operator causes the rotation of two ceramic discs relative to each other. As the ceramic discs have apertures which are aligned/ unaligned by the limited amount of rotation, rotation results in the opening or closing of the tap assembly in approximately a quarter turn of the tap handle.

However, ceramic disc taps are difficult to service and to maintain, a requirement that often occurs in hard water areas, as they have a complicated construction and a large number of moving parts. They are also sensitive to shock and may be damaged by rough handling. As a result, the entire cartridge is generally replaced, as repair could prove more costly. Further, replacement cartridges are not universally interchangeable, as parts from different manufacturers may not be compatible.

It will be appreciated that any discussion herein in respect of prior art publications or devices is not to be taken as an admission regarding the common general knowledge of a person skilled in the art.

Summary of the invention

According to a first aspect of the invention there is provided a valve assembly for regulating fluid flow including: a spindle defining a central axis, the spindle having an actuable end and a valve end; a spindle housing defining a central aperture for receiving the spindle, the spindle and the spindle housing including complemental formations for allowing the axial displacement of the valve end of the spindle on rotation of the actuable end thereof; and travel adjustment means for enabling adjustment of the upper and lower limits of travel of the valve end of the spindle. The travel adjustment means may include at least one axially adjustable component carried on at least one of the spindle and the spindle housing.

The at least one axially adjustable component may include at least one insert carried on one of the spindle housing and spindle. The travel adjustment means may include upper and lower stops, carried on the other of the spindle housing and spindle, on either side of the at least one insert, at least one of the insert and upper and lower stops being axially adjustable for enabling adjustment of the upper and/or lower limits of travel of the valve and of the spindle.

Preferably, the spacing between the insert and the stops is determinative of the extent of travel of the spindle.

Preferably, the insert is axially adjustable, and is carried on the spindle.

Alternatively, the insert may be axially adjustable and may be carried on the spindle housing. Conveniently, the complemental formations include a threaded portion on the spindle and a complementally threaded portion on the spindle housing.

Typically, the upper and lower stops are carried on the spindle between the actuable end and threaded portion. Advantageously, the insert may be positioned so that the limits of rotation of the spindle correspond to the open and fully closed positions of the valve end.

The open position may range from fully open (corresponding to maximum flow) to partially open (corresponding to restricted flow), with the thickness of the insert being determinative of the extent to which the valve is openable. Preferably the at least one insert has upper and lower abutment faces for abutting the respective upper and lower stops.

Optionally the upper and lower abutment faces may be located on upper and lower inserts respectively, the spacing of the inserts being variable.

Alternatively, the abutment faces may be defined on a single insert. Advantageously the insert may be selected from a range of interchangeable inserts having differing thicknesses for enabling the extent of displacement of the valve end to be adjusted.

Conveniently the insert may be received in a second complementally threaded portion of the spindle housing. Advantageously the insert may be a circumferentially threaded annulus which extends about the spindle and is threadingly engageable with the second complementally threaded portion of the spindle housing.

Optionally the first and second threaded portions of the spindle housing may be of opposite handedness such that rotation of the spindle relative to the spindle housing does not disengage the insert. Advantageously the insert may include at least one key opening for engagement with a key tool. Preferably, the adjustment tool is sized so as to extend about the upper stop and engage with the opening in the insert.

Advantageously the upper and lower stops may be upper and lower washers.

Preferably the upper washer is maintained in position using a crescent retaining ring, the crescent retaining ring being beatable in a recess of the spindle. Conveniently the lower washer may be maintained in position by contacting the internally threaded portion.

Advantageously the valve assembly may further include a sealing cap mountable to the top of the spindle housing. Advantageously, the threaded portions of the spindle and spindle housing constitute multi-start threads, and preferably are in the form of a double start thread arrangement.

The invention extends to a valve assembly which includes a selection of interchangeable inserts having a range of predetermined thicknesses. The travel adjustment means may include upper and lower axially adjustable inserts carried on the spindle housing and an intermediate stop or retainer carried on the spindle.

Preferably the valve assembly includes spindle housing adjustment means to position the spindle housing in a desired closed position relative to a desired valve handle position and a locking means to lock the spindle housing in said desired position. The locking means may include a threaded locking ring arranged to be screwed down over a complementally threaded spindle housing and a sealing arrangement for providing a fluid tight seal between the threaded locking ring and the spindle housing.

According to a second embodiment of the invention there is provided a tap valve assembly for regulating fluid flow including: a spindle defining a central axis, the spindle having an actuable end and a valve end; a spindle housing defining a central aperture for receiving the spindle, the spindle and the spindle housing including complemental formations for allowing the axial displacement of the valve end of the spindle on rotation of the actuable end thereof ; and at least one axially adjustable insert carried on the spindle housing and upper and lower stops carried on the spindle for enabling adjustment of the upper and lower limits of travel of the valve end of the spindle. According to a third aspect of the invention there is provided a valve assembly for regulating fluid flow including: a spindle defining a central axis, the spindle having an actuable end and a valve end; a spindle housing defining a central aperture for receiving the spindle, the spindle and the spindle housing including complemental formations for allowing the axial displacement of the valve end of the spindle on rotation of the actuable end thereof; a travel adjustment means comprising at least one axially adjustable insert carried on at least one of the spindle and the spindle housing for enabling adjustment of at least one of the upper and lower limits of travel of the valve end of the spindle and: spindle housing adjustment means to position the spindle housing in a desired closed position relative to a desired valve handle position and a locking means to lock the spindle housing in said desired position. The invention extends further to an insert for a valve assembly of the type described above, the insert being annular and having an upper face including tool engaging means and a lower face spaced a predetermined distance apart, the outer or inner circumference of the insert being threaded for engagement with a complementary internally threaded opening of a spindle housing of a tap, or with a complementally threaded spindle the distance between the upper and lower faces determining the extent of travel of the spindle.

Brief description of the drawings

Notwithstanding any other forms, which may fall within the scope of the present invention, the present invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1a shows a cross sectional view of the valve assembly according to a first embodiment of the present invention;

Figure 1 b shows a cross sectional view of the valve assembly of Figure 1a when fitted as part of a tap; Figure 2a shows a perspective view of the spindle which is received in the spindle housing of Figure 3a;

Figure 2b shows a front view of the spindle of Figure 2a; Figure 2c shows a side view of the spindle of Figure 2a; Figure 3a shows a longitudinal cross sectional view of the spindle housing of the valve assembly of Figure 1a;

Figure 3b shows a perspective view of the spindle housing of Figure 3a;

Figure 4 shows an exploded perspective view of components received in the spindle housing shown in valve assembly of Figure 1a, in which the spindle has been removed for clarity;

Figure 5 shows a cross sectional view of a valve assembly according to a second embodiment of the invention;

Figure 6 shows a cross sectional view of a valve assembly according to a third embodiment of the invention; Figure 7 shows a cross sectional view of a valve assembly according to a fourth embodiment of the invention;

Figure 8 shows a cross sectional view of a valve assembly according to a fifth embodiment of the invention, and

Figure 9 shows a cross sectional view of a valve assembly according to a sixth embodiment of the invention.

Figure 10 shows a rear view of a valve assembly according to a seventh embodiment of the invention when fitted as part of a tap;

Figure 11 shows a cross sectional view along line A-A of Figure 10; Figure 12 shows a top plan view of the valve assembly of Figure 10; Figure 13 shows a cross sectional view of the valve assembly of Figure 10 in the open position;

Figure 14 shows an exploded cross sectional view of the inner components of the valve assembly of Figure 11 including a soap shield; Figure 14a shows a perspective view of a retaining ring forming part of the spindle assembly of Figure 10; and

Figure 14b shows a perspective view of a key tool. Detailed description of the embodiments Referring first to Figures 1a and 1 b, a valve assembly 110 includes a spindle 120 which is received in a spindle housing 140. The spindle 120 includes a valve end 122 having an axial bore 124 for receiving the stem 126 of a tap valve 128 (Figure 1 b). The opposite end 130 of the spindle 120 is splined so as to receive a valve or tap handle 132 as shown in Figure 1 b. The spindle 120 includes an externally threaded portion 134 intermediate the valve end 122 and the splined end 130.

The spindle housing 140 has a central aperture 142 for receiving the spindle 120.

A circumferential slot 144 for receiving an o-ring seal 146 is provided towards the valve end of the spindle 120 for allowing the spindle to sealingly engage with the central aperture 142 as it moves axially therein and for preventing the influx of liquid through the aperture 142.

The threaded portion 134 of the spindle engages a first complemental internally threaded portion 138 defined within the spindle housing 140. An annular threaded insert 154 is carried on the spindle housing 140 between a lower stop washer 152 and an upper stop washer. The threaded insert 154 engages with a complemental internally threaded opening 156 of the spindle housing 140. The upper washer 153 is retained in place by a crescent retaining ring 160 (see Figure 4) which is received in a slot 162 formed in the shaft 150 of the spindle 120.

The threaded insert 154 is screwed up and down within the spindle housing 140 so as to allow for adjustment of the locations of the limits of travel of the spindle 120 as will be described further on in the specification.

In Figure 1 b, the valve assembly 110 is shown mounted in position within a tap or faucet body 170, with a threaded end 172 of the spindle housing 140 screwed into a complementally threaded opening 174 defined in the tap body 170.

The valve end 122 of the spindle 120 includes a hemispherical rubber valve head 176 which is received in the axial bore 124. The valve head 176 locates on the valve seat 178 when the tap is in the fully closed position. Rotation of the valve handle or lever 132 in the counter-clockwise direction (or if a left handed thread is used, in a clockwise direction) opens the tap by causing axial displacement of the spindle via the complementally threaded portions 134, 138. The axial displacement of the spindle results in displacement of the valve head 176 from the valve seat 178 to open the flow passage 182.

In the closed position shown it can be seen that the upper washer 153 and retaining ring 160 prevents further rotation and downward travel of the spindle 120 as it abuts the upper surface of the threaded insert 154. The spindle 120 is rotatable from the closed position shown to an open or partially open position until the lower stop washer152 abuts the lower face of the threaded insert 154. Accordingly, adjustment of the axial position of the insert 154 carried on the spindle housing (in the manner set out below) defines the limits of rotation of the spindle 120. The adjustment is particularly useful to ensure the limits of travel of the spindle correspond to the fully open and fully closed states of the valve assembly.

The insert 154 is a circumferentially threaded annulus which extends about the spindle, with the thread of the insert 154 and the threaded opening 156 of the spindle housing having an opposite hand compared to that of the threaded portions 134 of the spindle shaft and spindle housing 138 to prevent rotation of the spindle 120 in the spindle housing 140 from displacing the insert 154.

The capacity to adjust the position of the insert is useful in retrofitting the spindle to a pre-existing tap, particularly where the seat of the tap has been recut on a number of occasions. The effect of recutting the seat is to increase the vertical distance of the seat from the threaded opening of the spindle housing. Where the closed position of the spindle in the spindle housing is unable to be modified, as is the case in conventional lever ^ΛA turn tap assemblies, the valve head 176 may not effect a proper seal against the valve seat 178.

The amount of vertical travel of the spindle 120 within the spindle housing 140 according to the embodiment of the present invention shown is defined by the difference between the distance marked 'D' between the upper and lower stop washers 152, 153 and the thickness of the insert 154 marked T". (Of course if two separate inserts were used, the distance T would be between the upper surface of the upper insert and the lower surface of the lower insert).

Selection of an insert 154 that has a thickness T equal to half the distance D will result in a permitted distance of vertical travel of 14 D. Advantageously, the distance between the upper 153 and lower washers 152 is maintained constant, while the thickness of the insert T may be adjustable. This arrangement allows the adjustment of the limits of travel without any change being required in the location of the slot 162 on the shaft of the spindle 120.

The pitch of the screw thread selected for the spindle housing and the spindle dictates the amount of displacement per rotation. That is, the rotational travel of the spindle in a clockwise or a counter-clockwise direction will have the effect of raising or lowering the spindle shaft and the insert along the axis of the spindle shaft and spindle body by an amount per revolution dictated by the pitch of the selected screw thread.

As is apparent from Figure 2a, 2b the threaded opening 134 of the spindle may include double start Acme threads 190, 192 having a pitch P, in this case 8mm. It is clear that an increase in pitch will increase linear travel of the spindle along its axis when rotated relative to the spindle housing. By providing a two start thread, axial displacement is effectively doubled for the same degree of rotation when compared to a single start thread. This means for the embodiment shown, one revolution of the spindle in the housing results in vertical travel of 8mm, and a VA turn results in vertical travel of 2mm. If the upper and lower washers are spaced apart by 8mm, and an insert having a thickness T of 4mm is used; the vertical travel permitted is 4mm. This is achieved in half a revolution. Of course, inserts of other thicknesses may be used, for example an insert with a thickness of 6mm, will allow vertical travel of 2mm corresponding to a ^ΛA revolution of the spindle in the spindle housing. Referring to Figure 3a and Figure 3b it can be seen that the pitch of the first complementally threaded opening 148 of the spindle housing 140 also uses a double start thread for engaging with the double start Acme threads 190, 192 of the spindle. Adjustment of the position of the insert 154 on the second complementally threaded opening 156 results in adjustment of the limits of travel in the manner discussed above. Referring to Figure 4, the exploded view of the assembly with the spindle removed for clarity includes the lower washer 152, the threaded insert 154, the upper washer 153 and the crescent retaining ring 160. The threaded insert 154 includes diametrical key channels 155 for engagement with an adjusting tool 196. The adjusting tool 196 has two downwardly depending prongs 197, which locate within the channels 155 of the threaded insert 154 and allow the insert to be screwed up and down within the spindle housing.

An optional sealing cap 198 acts as a soap shield, having a threaded portion 199 and a pair of bores 200. The bores 200 of the cap 198 may be sized so as to receive the downwardly depending prongs 197 of the adjusting tool 196 for enabling the cap to be answered for accessing the insert. The central aperture 201 of the cap 198 is sized so that it is a firm sliding fit about the spindle shaft 150. The cap 198 may be produced having either left or right hand thread arrangements 199, depending on the thread arrangement of the second complementally threaded region 156. Both the sealing cap 198 and the insert 154 are formed from a hard plastics heat resistant material such as injection moulded acetyl.

The sealing caps may be colour coded, typically red in the case of a left hot tap insert, which has a right hand thread, and blue in the case of a right cold tap, which has a left hand thread. With reference to Figure 1 b, the following is a description of how the insert 154 is adjusted on the spindle housing 140 to achieve a successful seal between the valve head 176 and the valve seat 178 shown in Figure 1 b.

The spindle 120 may be inserted within the spindle housing 140 by screwing it either clockwise or counter-clockwise (depending on whether a left or right hand screw fit is provided). The lower washer 152 may then be placed so that it extends about the spindle, and sits on the upper start of the threaded portion 134 of the spindle.

An insert is then chosen by the operator according to the desired extent of vertical travel which, with the pitch of the threaded portions 134 and 138, is determinative of the number or fraction of turns between the open and closed positions. In the closed state the valve head 176 will be in contact with the valve seat 178.

The amount of downward pressure to require a satisfactory seal between the valve head and the seat will vary depending on the type of valve being used and the quality of the seal 176. The required setting can be tested by opening the water supply valve and checking if there is leakage.

The upper washer 153 and retaining ring 160 are sized to accommodate the prongs of the adjusting tool around their outer diameters and provide access to engage with the channels 155 in the insert. Holding the spindle in the closed position, the insert can now be adjusted upwardly to bring the washer153 into firm contact with the underside of the crescent retaining ring 160. This sets the sealing valve assembly to seal effectively with a positive stop and without excessive downward pressure on the valve head 176, thereby preventing damage to the assembly and prolonging its effective sealing lifespan.

In the case of % turn taps it is aesthetically desirable to have the lever handle of the tap at 90 degrees to the bench top or wall when the tap is in the closed position. This may be achieved by a combination of selectively positioning the handle on the splined end 130 of the handle as close to 90 degrees as possible, in conjunction with fine tuning the position of the handle by adjusting the position of the insert 154 in the downward direction.

The tap handle is turned clockwise to seal the valve. It is important to note that with this design it is impossible to over-tighten a valve as the interaction between the insert and end stop of the recess prevents this from happening.

It will be appreciated that there are numerous other variations of valve assemblies falling within the scope of the present invention.

In one embodiment, the insert is carried on the spindle, and is adjustable by having a threaded aperture which is screwed onto a corresponding threaded portion of the spindle. In this case, upper and lower stops are fitted to the spindle housing. The upper stop may be constituted by the under surface of the soap shield or sealing cap

198.

In a further embodiment, lower and upper stops are adjustable, and are in the form of threaded inserts or discs similar to the insert 154, but significantly thinner. A fixed stop is then carried on the spindle between the upper and lower adjustable inserts. These and other embodiments will now be described in more detail with reference to Figures 5 to 14b. Each of the embodiments of the valve assembly in Figures 5 to 14b include a locking ring 273. A detailed description of the locking ring 273 is described with reference to Figures 10 to 14b. Referring now to Figure 5, a second embodiment of a valve assembly 210 is shown having a spindle 212 which is threadingly received within a spindle housing 214. The spindle 212 is formed with an upper threaded portion 216 onto which is screwed an annular insert 218 having a complemental internal thread 220. The insert is located within a top opening in the spindle housing 214, which is capped with a soap shield 222, the lower surface of which defines an upper stop 224 when impacting with the annular insert 218. A lower stop is defined by an internal shoulder 226 of the spindle housing 214.

The upper and lower limits of travel of the spindle 212 are adjusted by rotating the annular insert 218 respectively clockwise or counter-clockwise so as to cause it to move up and down the spindle 212. As a result, the upper and lower limits of travel of the spindle 212 can be varied. As was the case in the previous embodiment, the extent of travel can simply be varied by removing the insert and replacing it with a thicker or thinner insert to respectively limit or increase such travel.

Referring now to Figure 6, a third embodiment of a valve assembly 230 is shown having a spindle 232 threadingly received within a spindle housing 234. In contrast to the first embodiment, in which an insert is adjustable between a pair of fixed stops, a set of upper and lower inserts 236 and 238 serve as adjustable upper and lower stops for limiting the travel of a fixed circlip or retaining ring 239 carried on a spindle 232. The lower insert 238 is adjusted to vary the lower limit of travel, and the upper insert 236 may be independently adjusted to limit the upper limit of travel. As a result, the total extent of travel of the spindle, which corresponds to the distance "D" between the upper face of the lower insert and the lower face of the upper insert less the thickness "T" of the or retaining ring 239, can be adjusted by simply moving the upper and lower inserts

236, 238 towards or away from one another. As a result, inserts of varying thicknesses are not required. The upper face of the lower insert 238 is formed with a slot arrangement similar to that of the insert 154, as is the upper insert 236. During the adjustment process, the soap shield or cap 198 is unscrewed, as is the upper insert 236. The axial position of the lower insert 238 is then adjusted so that when the valve head of the spindle head is firmly and sealingly seated within the valve seat, the lower face of the retaining ring 239 abuts firmly against the upper face of the lower insert 238. The upper insert 236 is then screwed into a position in which it defines the upper limits of travel, in which the upper face of the retaining ring 239 abuts against the lower face of the upper insert 236.

Turning now to Figure 7, a fourth embodiment 240 of the valve assembly is shown having a spindle 242 threadingly received within spindle housing 140. The adjustable insert 154 is similar to that illustrated in Figures 1-5. The lower face 244 of the insert 154 abuts against the uppermost turn 246 of the main thread of the spindle

242 to define the maximum opening position of the valve.

The closing position of the valve is defined by a retaining ring or "E" clip 248 which is fitted to one of a series of undercuts 249 defined in the spindle 242 to allow the closure position to be varied. The lower face of the retaining ring 248 abuts against an upper face of a soap shield 250 to define the closing position. The closing position may be raised by repositioning the retaining ring 248 within one of the lower undercuts 249.

Referring now to Figure 8, a fifth embodiment of a valve assembly 252 is shown which is similar to the fourth embodiment, save that the retaining ring and groove arrangement is replaced by a continuously adjustable arrangement for allowing the lower limits of travel of the valve end to be continuously varied. This is achieved by providing a threaded portion 254 on the spindle 242 onto which an annular adjustable closing stop 256 is screwed. The maximum position of downward travel is determined when the lower face 258 of the adjustable stop 256 abuts against an uppermost face 260 of the spindle housing 261. It can readily be seen how the lower limit of travel can easily be adjusted by turning the adjustable closing stop 256 so that it moves axially up or down relative to the spindle 242.

In Figure 9, a sixth embodiment of a valve assembly 262 of the invention is shown in which the spindle 242 is fitted with a retaining ring 264 and spacer washer 266. The upper face of the spacer washer 266 abuts against a lower face of soap shield 198 to define the upper limits of travel. The lower limits of travel are defined by an annular insert 268 which sits on a shoulder 270 defined within an opening in the spindle housing 140. In the illustrated embodiment, the insert 268 is not threaded, and adjustment of the extent of travel is simply effected by replacing insert 268 with a thicker or thinner insert. As a further alternative, the insert 268 may be of the type illustrated in Figures 1-5, having an external thread which screws into a corresponding threaded opening of the spindle housing 140 so that the position of the insert may be continuously adjusted.

Referring to Figures 10 to 14b, a seventh embodiment of a valve assembly 271 is shown with similar or identical components as in previous embodiments identified with corresponding numerals, generally suffixed with an "A".

The valve assembly 271 includes a spindle 120A which is threadingly received in a spindle housing 140A. The spindle 120A includes a valve end 122A having an axial bore 124A for receiving the stem 126A of a tap valve 128A.

The threaded end 172A of the spindle housing 140A is screwed into a complementally threaded opening 174A defined in the tap or faucet body 170A. An outer face 272 of the spindle housing 140A is threaded to receive a locking ring 273. That portion of the threaded outer face which is exposed above the locking ring is covered with a complementally threaded bonnet. When the spindle housing 140A is screwed into the tap or faucet body 170A the locking ring 273 is screwed onto the spindle housing 140A to lock the valve assembly 271 in position in the tap or faucet body 17OA. A circumferential slot 278 for receiving an o-ring seal 279 is provided on the outer face of the spindle housing 140A to allow the spindle housing 140A to sealingly engage with the locking ring 273 to prevent leakage. Further, a sealing washer 277 sits between the locking ring 273 and the tap or faucet body 170A to prevent leakage.

Advantageously, the spindle housing 140A may be axially adjusted to a desired position within the threaded opening 174A in the tap or faucet body 170A. The opposite end of the spindle 130A has flats 274 to receive a valve or tap handle (not shown). When the spindle 120A is placed in the closed position the handle (not shown) may not be aligned at the correct angle in that it interferes with an adjacent fixture such as a counter. This is overcome by loosening the locking ring 273 and incrementally turning the spindle housing 140A anticlockwise to raise it and then screwing the spindle 120A down until the valve 128A sits firmly in the valve seat in the fully closed position with the handle of the spindle in the desired position. At this stage, the locking ring is tightened to lock the spindle housing 140A in position. With the valve in the fully closed position the threaded insert 154A is then screwed upusing the adjusting toll 196A until it abuts the retaining ring, thereby creating a hard stop which firmly sets the lower limit of travel of the valve. As a result, the tap handle it set in the right position and wear on the jumper valve 128A is reduced as it cannot be overtightened.

The spindle 120A is fitted with two spacer washers 275 the lower one of which sits on a shoulder located at the uppermost turn of the main thread of the spindle 246A. Each spacer washer represents a restriction of one quarter turn. A threaded insert 154A engages with a complemental internally threaded opening 156A of the spindle housing 140A in a similar way as described the previous embodiments. Above the threaded insert 154A, a retaining ring 160A is beatable in a recess 162A formed in the shaft of the spindle 120A. An optional sealing cap 198A (see Figure 14) acts as a soap shield having a threaded portion 199A and a pair of bores 200A.

The amount of vertical travel of the spindle 120A within the spindle housing 140A according to the embodiment is defined by the difference between the distance marked

"s" in Figure 11 between the lower surface of the retaining ring 160A and the upper surface of the uppermost spacer washer 275 and the thickness of the threaded insert

154A marked "n". The distance "s" may be adjusted by adjusting the number of spacer washers 275 on the shoulder located at the uppermost turn of the main thread of the spindle 246A, typically to allow ^ΛA, !4 and ³A turns of the handle between the open and closed positions.

Figure 14 shows an exploded view of the assembly with the spindle removed for clarity, including the spindle housing 140A, the locking ring 273, the spacer washers 275, the threaded insert 154A, the retaining ring 160A and the soap shield 198A. The retaining ring 160A includes slots 276 formed in the outer diameter. The threaded insert 154A includes diametrical key channels 155A for engagement with an adjusting tool 196A. The adjusting tool 196A has two downwardly depending prongs 197A, which locate within the channels 155A of the threaded insert 154A via openings in the retaining ring and allow the insert to be screwed up and down within the spindle housing 140A. It will be appreciated that the various valve assembly embodiments of the invention described above offer a range of combinations of a valve opening capacity and handle turn options to satisfy a range of commercial and domestic applications

The various embodiments of valve assemblies may be used with lever style %, Vi or YA turn rapid rising spindles (by selecting the thickness of the insert used) or for non limited turn rapid rising spindles (by removing the insert altogether). Non limited rapid rising spindles may be used in a variety of situations, including for example on cold water taps on bathtubs. In certain applications, for example, the user may require a slow rising spindle for a hot water outlet (e.g. using a single start thread) and a rapid rising spindle for a cold water outlet so that an element of safety is provided in relation to the sudden full flow of hot water.

In this regard, the valve assemblies of the embodiments of the present invention are generally applicable in a situation in which desired rotation between the fully open and fully closed positions is less than a full rotation. In the case of a cold water tap, a quarter turn embodiment could be utilised, such as that provided by the embodiment shown in figure 1B. A tap having a star handle with a ³A turn can thus readily be replaced with !4 turn lever handle without having to replace the entire valve assembly.

Thus, once the valve assembly is fitted to a tap seat, modification of the thickness of the insert or removal of the spacers is all that is required to change the behaviour of the tap. In particular, in a water restriction environment full flow tap arrangements may be modified to limited flow arrangements simply by adding an insert or replacing a thinner insert with a thicker one.

Reseating or recutting of the tap body seat surface can be also be effected relatively easy, without the cost of replacing an entire cartridge. Further, the adjustment of the valve seat may be effected without having to shut off the water supply. This adjustment is sometimes required after a settling in period following the recutting of the tap body seat. The valve assembly of an embodiment of the present invention provides fine control over the closed position of the tap, which minimises leakage. In particular, ongoing downward axial adjustment of the spindle may be effected so that effective sealing may be maintained as the resilient valve head compacts over time. It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims

1. A valve assembly for regulating fluid flow including: a spindle defining a central axis, the spindle having an actuable end and a valve end; a spindle housing defining a central aperture for receiving the spindle, the spindle and the spindle housing including complemental formations for allowing the axial displacement of the valve end of the spindle on rotation of the actuable end thereof ; and a travel adjustment means comprising at least one axially adjustable insert carried on at least one of the spindle and the spindle housing for enabling adjustment of the upper and lower limits of travel of the valve end of the spindle.

2. A valve assembly according to claim 1 in which the travel adjustment means includes upper and lower stops carried on the other of the spindle housing and the spindle, on either side of the at least one axially adjustable insert.

3. A valve assembly according to claim 2 in which the spacing between the insert and the upper and lower stops is determinative of the extent of travel of the spindle.

4. A valve assembly according to either one of claims 2 or 3 in which the insert is carried on the spindle.

5. A valve assembly according to either one of claims 2 or 3 in which the insert is carried on the spindle housing.

6. A valve assembly according to claim 5 in which the upper and lower stops are carried on the spindle between the actuable end and the threaded portion.

7. A valve assembly according to any one of the preceding claims 2 to 6 in which the insert is positioned so that the limits of rotation of the spindle correspond to the open and fully closed positions of the valve end of the spindle.

8. A valve assembly according to claim 7 in which the open position ranges from fully open (corresponding to maximum flow) to partially open (corresponding to restricted flow), with the thickness of the insert being determinative of the extent to which the valve is openable.

9. A valve assembly according to any one of the preceding claims 2 to 8 in which the at least one insert has upper and lower abutment faces for abutting the respective upper and lower stops.

10. A valve assembly according to claim 9 in which the upper and lower abutment faces are located on upper and lower inserts respectively, the spacing of the inserts being variable.

11. A valve assembly according to either one of claims 9 or 10 in which the abutment faces are defined on a single insert.

12. A valve assembly according to any one of the preceding claims 2 to 11 in which the insert is selectable from a range of interchangeable inserts having differing thicknesses for enabling the extent of displacement of the valve end to be adjusted.

13. A valve assembly according to any one of the preceding claims 2 to 11 in > which the insert is received in a second complementally threaded portion of the spindle housing.

14. A valve assembly according to claim 13 in which the insert is a circumferentially threaded annulus which extends about the spindle and is threadingly engageable with the second complementally threaded portion of the spindle housing.

15. A valve assembly according to either one of the preceding claims 13 or 14 in which the first and second threaded portions of the spindle housing are of opposite handedness such that rotation of the spindle relative to the spindle housing does not disengage the insert.

16. A valve assembly according any one of claims 2 to 15 in which the insert includes at least one key receiving formation for engagement with a key tool, the key tool being sized so as to extend about the upper stop and engage with the formation in the insert.

17. A valve assembly according any one of claims 2 to 16 in which the upper and lower stops are upper and lower washers, the upper washer being maintained in position using a retaining ring, the retaining ring being beatable in a recess of the spindle, and the lower washer being maintained in position by contacting the internally threaded portion of the spindle.

18. A valve assembly according to any one of claims 2 to 16 in which the lower stop includes at least one spacer washer.

19. A valve assembly according to claim 18 where in the thickness of one spacer washer corresponds to one of a quarter, half and three quarter turn of the spindle.

20. A valve assembly according to either one of claims 18 or 19 where in the spacing between the upper stop and the lower stop is adjustable by adjusting the number of spacer washers in a stack.

21. A valve assembly according to any one of claims 2 to 20 which further includes a sealing cap mountable to the top of the spindle housing.

22. A valve assembly according to any one of claims 2 to 20 in which the threaded portions of the spindle and spindle housing constitute multi-start threads.

23. A valve assembly according to any one of the preceding claims which includes a selection of interchangeable inserts having a range of predetermined thicknesses.

24. A valve assembly according to any one of the preceding claims which includes spindle housing adjustment means to position the spindle housing in a desired closed position relative to a desired valve handle position and a locking means to lock the spindle housing in said desired position.

25. A valve assembly according to claim 24 where in the locking means includes a threaded locking ring arranged to be screwed down over a complementally threaded spindle housing and a sealing arrangement for providing a fluid tight seal between the threaded locking ring and the spindle housing.

26. A valve assembly according to claim 1 in which the travel adjustment means includes upper and lower axially adjustable inserts carried on the spindle housing and an intermediate stop or retainer carried on the spindle.

27. A tap valve assembly for regulating fluid flow including: a spindle defining a central axis, the spindle having an actuable end and a valve end; a spindle housing defining a central aperture for receiving the spindle, the spindle and the spindle housing including complemental formations for allowing the axial displacement of the valve end of the spindle on rotation of the actuable end thereof ; and at least one axially adjustable insert carried on the spindle housing and upper and lower stops carried on the spindle for enabling adjustment of the upper and lower limits of travel of the valve end of the spindle.

28. A valve assembly for regulating fluid flow including: a spindle defining a central axis, the spindle having an actuable end and a valve end; a spindle housing defining a central aperture for receiving the spindle, the spindle and the spindle housing including complemental formations for allowing the axial displacement of the valve end of the spindle on rotation of the actuable end thereof ; a travel adjustment means comprising at least one axially adjustable insert carried on at least one of the spindle and the spindle housing for enabling adjustment of at least one of the upper and lower limits of travel of the valve end of the spindle and: spindle housing adjustment means to position the spindle housing in a desired closed position relative to a desired valve handle position and a locking means to lock the spindle housing in said desired position.

29. An insert for a valve assembly according to any one of the preceding claims, the insert being annular and having an upper face including a tool receiving formation and a lower face spaced a predetermined distance apart from the upper face, the outer or inner circumference of the insert being threaded for engagement with a complementary internally threaded opening of a spindle housing of a tap, or with a complementally threaded spindle, the distance between the upper and lower faces determining the extent of travel of the spindle, and the insert being axially adjustable by being screwed up and down on the spindle or housing.

30. A valve assembly substantially as herein described with reference to the accompanying drawings.

31. An insert for a valve assembly substantially as herein described with reference to the accompanying drawings.