AU2008217553A1 - Tap construction and operation - Google Patents

Description

WO 2008/101274 PCT/AU2008/000188 TAP CONSTRUCTION AND OPERATION Field of the Invention The present invention relates to taps (or faucets as the devices are termed in the USA). 5 For domestic applications, there are two basic types of taps, the traditional jumper valve tap and the ceramic disc tap. Background Art The jumper valve tap has been used for many decades and closes the water supply by 10 means of a disc having a stem which is pushed against a valve seat so as to stop the flow. Generally this type of tap suffers from the disadvantage that the seal between the disc and the valve seat deteriorates over time and therefore an increasing amount of pressure is required to stop the flow as the jumper valve ages. 15 The ceramic disc tap utilises two discs which are each provided with a through hole. The discs are rotated one relative to the other in order to align or mis-align the hole so as to open and close the tap respectively. This type of arrangement suffers from the disadvantage that small particles of grit, or the like, can enter between the discs and damage them. The tap then leaks as a consequence of this damage. 20 Prior art searches conducted after the priority date have disclosed DE 3,231,298; FR 2,640,020 and SU 1,685,117. All three of these prior publications disclose a tap with a stem valve (rather than a jumper valve) which is opened against the inlet pressure. However, the stem valve is directly connected with, and is rotatable with, 25 the stem valve shaft and handle. As a consequence, the sealing surface of the stem valve and the circular orifice within which it is located, rotate relative to each other during the opening and closing of the tap. Furthermore, since the stem valve is held rigidly either open or shut, and does not 30 include an independently moveable jumper, there is no possibility of providing a tap which, when open, can seal against reverse flow caused by temporary or transient pressure fluctuations in which the outlet pressure exceeds the inlet pressure. 1 WO 2008/101274 PCT/AU2008/000188 Genesis of the Invention The genesis of the present invention is a desire to create an alternative to the abovementioned prior art types of tap. 5 Summary of the Invention In accordance with a first aspect of the present invention there is disclosed a tap comprising a tap body having an inlet and an outlet and a valve driver mounted for reciprocating movement relative to the tap body, said tap further comprising an annular throat defining a sole passageway between said inlet and outlet and a jumper 10 located in said throat, said jumper being urged by inlet pressure further into said throat, being dimensioned to seal said throat, and being movable away from said throat by the motion of said valve driver. In accordance with a second aspect of the present invention there is disclosed a 15 method of opening and closing a tap comprising a tap body having an inlet and an outlet, and a valve driver mounted for reciprocating movement relative to the tap body, said method comprising the steps of: (i) providing an annular throat to define a sole passageway between said inlet and outlet, 20 (ii) locating a jumper in said throat, (iii) moving said jumper away from said throat by movement of said valve driver in a first direction to open said tap, and (iv) permitting inlet pressure to urge said jumper into sealing engagement with said throat by movement of said valve driver in a second direction opposite to said first 25 direction to close said tap. Brief Description of the Drawings Several embodiments of the present invention will now be described with reference to the accompanying drawings in which: 30 Fig. 1 is a schematic partial vertical cross section through a prior art jumper valve tap, Fig. 2 is a similar cross sectional view through the tap of a first embodiment, Fig. 3 is a view similar to Fig. 2 but illustrating a tap of a second embodiment, 2 WO 2008/101274 PCT/AU2008/000188 Fig. 4 is a view similar to Figs. 2 and 3 but illustrating a third embodiment with an alternative valve closure mechanism, Fig. 5 is a view similar to Fig. 1 but illustrating a further embodiment of the present invention which is able to be retrofitted to existing taps, 5 Fig. 6 is an enlarged view of a modified throat of the tap 20 of Fig. 2, and Fig. 7 is a longitudinal cross-sectional view through a tap of a still further embodiment. Detailed Description 10 The traditional tap 1 has a tap body 2 which is traditionally cast from brass and which includes a machined valve seat 3. The tap has an inlet 8 which leads towards the valve seat 3 and an outlet 4 which leads away from the valve seat 3, the directions of water flow being illustrated by arrows in Fig. 1. 15 Located above the valve seat 3 is a jumper valve 5 which consists of a disc 6 and a stem 7. Also located above the valve seat 3 is a threaded aperture 9 which threadably receives in water tight fashion a spindle body 10. Reciprocally mounted within the spindle body 10 is valve driver 12 which can be advanced towards, or retreated away from, the valve seat 3 by rotation of the tap handle (not illustrated). 20 Rotation (in a clockwise direction as viewed from above) of the handle of the tap causes the valve driver 12 to engage the jumper valve 5 and thus drive the jumper valve 5 into engagement with the valve seat 3 and close off flow through the tap 1. Alternatively, rotation of the handle of the tap in the opposite direction (anti 25 clockwise) retreats the valve driver 12 away from the valve seat 3 and thus the pressure of the water in the inlet forces the jumper valve 5 away from the valve seat 3 to open the valve. The conventional tap 1 with its jumper valve 5 has a significant and desirable 30 advantage that in the event of the pressure at the inlet of the tap being less than the pressure at the outlet of the tap, then the jumper valve 5 is sucked towards the valve seat 3 and closes off any flow in the reverse direction. This can be a significant advantage in maintaining the integrity of a community mains supply. 3 WO 2008/101274 PCT/AU2008/000188 Turning now to Fig. 2, the first embodiment of the present invention is illustrated in which the tap 20 has a tap body 2 and valve seat 3 as before. Threadably received within the threaded aperture 9 is a spindle body 21 which includes a valve driver 22. The valve driver 22 is caused to reciprocate by the tap handle (not illustrated) in 5 substantially conventional fashion. Received in the base of the spindle body 21 is a sealing annulus 23 which at its base carries an O-ring 24. The spindle body 21 is rotated into the threaded aperture 9 until the O-ring 24 seals against the valve seat 3 thereby preventing any flow between the valve seat 3 and the spindle body 21. Fig. 2 illustrates the situation immediately prior to this seal being created. The spindle body 10 21 is provided with a pair of outlet apertures 26 the function of which will be explained hereafter. The sealing annulus 23 is provided with a tapered throat 27. Within the throat 27 is located a jumper 25 having a stem 29, a head 30 and a O-ring 31. As with a 15 conventional tap, rotation of the handle advances the valve driver 22 towards, or away from, the valve seat 3. Movement of the valve driver 22 towards the valve seat 3 means that the stem 29 is pushed downwardly thereby moving the O-ring 31 out of contact with the tapered throat 27 and opening the tap 20. As a consequence, water flows from the inlet 8 past the head 30 and into the volume between the spindle body 20 21 and the valve driver 22. Thereafter the water exits through the pair of outlet apertures 26 and into the outlet 4 of the tap 20. Conversely, if the valve driver 22 is moved away from the valve seat 3 then the pressure of the mains supply on the head 30 drives the jumper 25 upwardly as seen in 25 Fig. 2, so that the O-ring 31 comes into sealing contact with the frusto-conical surface of the tapered throat 27, thereby blocking the flow. Importantly, the pressure of the mains supply maintains the jumper 25 closed and therefore no great pressure is required by the operator in order to stop the flow. 30 If the conventional arrangement between the tap handle and the valve driver 22 is maintained, then the opening and closing directions of rotation of the handle for the tap 20 are opposite to that of the conventional tap 1. However, this reversal of direction of rotation which many consumers would find perplexing, can be easily sing the hand (or direction of rotation) of the conventional screw 4 WO 2008/101274 PCT/AU2008/000188 thread interconnecting the valve driver 22 and the handle with the consequence that the handle of the tap 20 is rotated in conventional fashion to open and close the tap. When the jumper 25 is moved downwardly as seen in Fig. 2 so as to open the tap 20, 5 an annular space is created between the O-ring 31 and the interior of the throat 27. Although the radial extent of this annulus is relatively narrow, the diameter of the annulus is relatively large and therefore the size of the opening is appreciable, especially in view of the pressure available in the mains supply to drive the flow. 10 A significant advantage for the above described arrangement is that the mains pressure is available to close the valve and therefore the valve is easily closed and the flow completely stopped, even if the O-ring 31 ages with time. In addition, the tap 20 is also easy to open since a substantial vertical downward force is created on the valve driver 22 by rotation of the handle. 15 A second embodiment of the present invention is illustrated in Fig. 3 and is identical to the arrangement illustrated in Fig. 2, save that the sealing annulus 23 is provided with a barbed rim 38. In this embodiment the sealing annulus 23 is preferably manufactured from plastics material and thus the barbed rim 38 is to a certain extent 20 flexible. As a consequence, the jumper 25 can be pushed stem first past the barbed rim 38 such that the O-ring 31 and head 30 deflect the barbed rim allowing the jumper 25 to move into the position illustrated in Fig. 3. The operation of the tap 40 of Fig. 3 is the same as that of Fig. 2 with the added 25 advantage that in the event that the inlet pressure should be less than the pressure of the outlet, then the jumper 25 moves downwardly as seen in Fig. 3 so as to bring the head 30 into contact with the barbed rim 38, thereby sealing the throat 27. Because the difference between the inlet and outlet pressure of the tap 40 will always be small under these circumstances, the seal between the head 30 and the barbed rim 38 does 30 not need to be very good in order to be effective. Thus the tap 40 of Fig. 3 has the desirable characteristic of the tap 1 of Fig. 1 of not permitting reverse flow through the tap. 5 WO 2008/101274 PCT/AU2008/000188 Turning now to Fig. 4, a further embodiment is illustrated in which the spindle body 21, valve driver 22 and sealing annulus 23 are as for Fig. 3. However, the jumper 25 of Fig. 3 is replaced by a spherical jumper or ball 55 which is preferably made from a stainless steel ball bearing or hard plastics material such as NYLON. A short stem 59 5 which is retained by means of a frictional fit in the valve driver 22 enables the ball 55 to be depressed by the valve driver 22 in order to open the tap 50. The tap 50 is closed by means of inlet pressure being applied to the ball 55 so as to drive same into contact with the tapered frusto-conical interior surface of the sealing annulus 23. 10 As in the arrangement of Fig. 3, the ball 55 can be driven past the barbed rim 38 which again functions to prevent reverse flow. Furthermore, when the tap 50 is open, the ball 55 rotates as the water flows past it. Thus each time the tap 50 is turned off, a fresh sealing surface of the ball 55 engages the throat 27. 15 Turning now to Fig. 5 an arrangement which is able to be retrofitted to the tap 1 of Fig. 1 to create the modified tap 60 of Fig. 5 is illustrated. The valve seat 3 is tapped so as to permit a threaded sleeve 63 (having a tapered throat 67 as before) to be received in the valve opening. A jumper 65 having a stem 69, an O-ring 61 and a head 70 is provided substantially as before. 20 In the arrangement of Fig. 5, as the valve driver 21 is advanced towards the valve seat 3, instead of the tap being closed, the tap 60 is opened since the stem 69 drives the 0 ring 61 out of contact with the tapered throat 67 thereby permitting flow of water through the tap 60. Conversely, as the valve driver 12 is moved away from the valve 25 seat 3, the pressure of the inlet on the head 70 drives the jumper 65 upwardly as seen in Fig. 5 thereby causing the O-ring 61 to sealingly engage with the throat 67 to close the flow. Thus although the arrangement of Fig. 5 is able to be retrofitted to an existing tap 1 so as to create a modified tap 60, the direction of rotation of the handle so as to open and close the flow is reversed where no modification to the spindle and 30 handle arrangement is made. Turning now to Fig. 6, here a modified throat 127 of the tap 20 of Fig. 2 is provided. The jumper 25 of Fig. 2 is modified to provide a jumper 125 which include a circlip The head 30 and its 0-ring 31 are essentially unchanged. The 6 WO 2008/101274 PCT/AU2008/000188 throat 127 is provided with a tapered or frusto-conical surface 227 (which provides a seal with the O-ring 31). The taper 227 leads into a first cylindrical wall 228 with which the O-ring 31 does not seal. The first cylindrical wall 228 leads into a second cylindrical wall 229 with which the O-ring 31 slidingly seals. 5 In normal operation, the inlet pressure exceeds the outlet pressure so the jumper 125 is driven vertically upwards as seen in Fig. 6. Thus the O-ring 31 seals against the taper 227 without any rotation of the O-ring 31 relative to the taper 227. 10 In the event that the outlet pressure (irrespective of whether the jumper valve 125 is open or shut) exceeds the inlet pressure then the jumper valve 125 is driven downwardly as seen in Fig. 6 until the head 30 enters into the second cylindrical wall 229. Here sliding sealing contact with the wall 229 and O-ring 31 occurs. Furthermore, the circlip 126 which has a diameter greater than that of the taper 227 15 prevents further downward movement of the head 30 beyond the position illustrated by dashed lines in Fig. 6, thereby ensuring the integrity of the seal between the O-ring 31 and wall 229. Thus a seal against reverse flow is ensured. An inexpensive garden tap 80 able to be fabricated from plastics is illustrated in 20 Fig. 7. The tap 80 has a bulbous body 81 having an inlet 82 and an outlet 83. The body 81 has a smooth cylindrical passage 84 which extends into the outlet 83 and is the prolongation of a threaded bore 85. A handle 87 has a stem 88 with a threaded portion 89 which is threadably engaged with the bore 85 so that rotation of the handle 87 advances the stem 88 towards, or retracts it from, the inlet 82. The end 89 of the 25 stem 88 remote from the handle 87 carries an O-ring 91 which seals against the smooth cylindrical passage 84. After the handle 87 and the stem 88 are initially installed and the stem end 89 is advanced into the outlet 83, a circlip 93 is pushed onto the stem end 89 via the outlet 30 83. The circlip 93 prevents the handle 87 and stem 88 being subsequently withdrawn from the body 81. A jumper 95 is fabricated from plastics and has a cylindrical stem 96 and a disc 97 -ring 98. The stem 96 is dimensioned to be received with a loose 7 WO 2008/101274 PCT/AU2008/000188 fit in a blind hole 90 formed in the stem end 89. The blind hole 90 opens into a concave recess 92. After the handle 87 and stem 88 have been installed, an annular barb 99 is inserted into the concave recess 92 via the outlet 83. Then the jumper 95 is inserted into the inlet 82 and the stem 96 is pushed through the annular barb 99 which 5 is thereby restrained on the stem 96. Since the diameter of the barb 99 exceeds that of the throat 86 interconnecting the inlet 82 and outlet 83, this prevents the jumper 95 being withdrawn from the inlet 82. In operation, the O-ring 98 seals the tapered inlet of the throat 86. However, as the 10 stem 88 is advanced to the right in Fig. 7, the stem 96 is moved by hole 90 into the position illustrated in Fig. 7, thereby allowing water, or other liquid or gas, to pass from the inlet 82 to the outlet 83. Turning the handle 87 in the opposite direction moves the stem 88 to the left as seen in Fig. 7 and allows the inlet pressure to close the jumper 95 against the throat 86. If the outlet pressure should exceed the inlet 15 pressure, then the jumper 95 moves to the right as seen in Fig. 7 and the barb 99 seals the throat 86 to a practically sufficient extent against reverse flow. The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the plumbing arts, can be made thereto 20 without departing from the scope of the present invention. For example, a particular advantage of the present invention is that the taps can be inexpensively fabricated from plastics materials. The term "comprising" (and its grammatical variations) as used herein is used in the 25 inclusive sense of "including" or "having" and not in the exclusive sense of "consisting only of'. 8

Claims (17)

1. A tap comprising a tap body having an inlet and an outlet and a valve driver mounted for reciprocating movement relative to the tap body, said tap further comprising an annular throat defining a sole passageway between said inlet and outlet and a jumper located in said throat, said jumper being urged by inlet pressure further into said throat, being dimensioned to seal said throat, and being movable away from said throat by the motion of said valve driver.

2. The tap as claimed in claim 1 wherein said jumper comprises a stem passing through said throat and being actuatable by said valve driver.

3. The tap as claimed in claim 2 wherein jumper said has a head facing said inlet and an O-ring carried by said head to seal said throat.

4. The tap as claimed in any one of claims 1-3 wherein said jumper is urged to seal said throat by reverse flow through said tap.

5. The tap as claimed in claim 4 wherein said throat includes a deformable rim past which said jumper is moved to locate said jumper in said throat, and against which said jumper is sealingly urged by said reverse flow.

6. The tap as claimed in any one of claims 1-5 wherein said annular throat is sealingly engaged with an annular valve seat.

7. The tap claimed in any one of claims 1-6 wherein said annular throat is carried by a spindle body and seals against an annular valve seat.

8. The tap as claimed in claim 7 wherein said spindle body includes at least one outlet aperture.

9. The tap as claimed in claim 7 or 8 wherein said annular throat includes an 0 ring which seals against said annular valve seat.

10. A method of opening and closing a tap comprising a tap body having an inlet and an outlet, and a valve driver mounted for reciprocating movement relative to the tap body, said method comprising the steps of: (i) providing an annular throat to define a sole passageway between said inlet and outlet, (ii) locating a jumper in said throat, (iii) moving said jumper away from said throat by movement of said valve driver in a first direction to open said tap, and (iv) permitting inlet pressure to urge said jumper into sealing engagement 9 WO 2008/101274 PCT/AU2008/000188 with said throat by movement of said valve driver in a second direction opposite to said first direction to close said tap.

11. The method as claimed in claim 10 comprising the further step of: (v) providing said jumper with an O-ring to sealingly engage the annular interior of said throat.

12. The method as claimed in claim 11 comprising the further step of: (vi) retaining said jumper within said throat by moving said jumper past a deformable projection.

13. The method as claimed in claim 12 comprising the further step of: (vii) forming said projection as a seal against which said jumper is urged by reverse flow to thereby throttle reverse flow through said tap.

14. The method as claimed in any one of claims 10-13 including the further step of: (viii) retrofitting a conventional tap to operate in accordance with said method.

15. The method as claimed in claim 14 including the further step of: (ix) sealingly engaging said annular throat with an annular valve seat,

16. The method as claimed in any one of claims 10-13 including the further step of: (x) providing a spindle body of said tap with said annular throat and at least one outlet aperture.

17. The method as claimed in claim 16 including the further step of: (xi) sealing said spindle body against a valve seat. 10