Title: "JUMPER VALVE"
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to a jumper valve for use in domestic faucets or bib-cocks or the like.
(2) Brief Description of the Prior Art
These faucets frequently develop troublesome leaks due to the deterioration of their jumper valves and/or valve seats. common type of jumper valve has a stem formed integrally with a coaxial disc, to which is fitted a disc-shaped valve washer of, for example, hard-fibre, leather or plastics material composition. The stem, coaxial disc and valve washer may be formed as integrally moulded plastics material.
After prolonged use, an annular depression is worn or compressed in the valve washer, this depression being formed around a central circular unworn part smaller in diameter than the. internal diameter of the valve seat. As the valve stem is a loose fitting in the bore of the faucet stem, the valve washer may be brought eccentrically onto the valve seat enabling the faucet to leak. When the valve seat has become worn or damaged, an effective seal cannot be formed between the valve washer and valve seat, also leading to leaks.
Jumper valves have been produced with a coned- type valve washer which engages the valve seat at the junction between the annular valve seat face and the bore through the valve seat. An annular depression is rapidly formed around the valve washer due to the compress¬ ion of the valve washer by the valve seat and leaks quickly occur.
BRIEF SUMMARY OF THE PRESENT INVENTION It is an object of the present invention to provide a jumper valve which provides at least two sealing
zones between the valve washer and the valve seat.
It is a preferred object to provide a jumper valve which is effective even if the valve seat is worn or damaged. It is a further preferred object to provide a jumper valve which is not damaged by over-tightening of the faucet.
Other preferred objects of the present invention will become apparent from the following description. I one aspect, the present invention resides in a jumper valve for domestic faucets, bib-cocks or the like, including:- a stem extending coaxially from a valve disc; and a valve washer having a central substantially frusto-conical or hemi-spherical portion surrounded by an annular disc portion.
Preferably the valve washer is formed of resiliently deformable material, for example rubber, neoprene, nylon, polyether, or other plastics material, and the valve washer may be moulded integrally with the stem and valve disc. Preferably the material has "memory" returning to its original shape after the removal of any deforming force e.g. due to overtightening of the faucet. Preferably the annular junction between the frusto conical or hemi-spherical portion and the annular disc portion is adapted to sealably engage the junction between the annular valve seat face and valve seat bore in the faucet. DESCRIPTION OF THE VIEWS OF THE DRAWINGS
To enable the invention to be fully understood, a number of preferred embodiments will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a sectional side view of a faucet fitted with a two-piece jumper valve of the present invention;
FIG. 2 is a perspective view of the jumper valve of FIG. 1; and
FIG. 3 is a perspective view of a one-piece jumper valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, the faucet 10 has a faucet body 11, with an inlet 12 and an outlet 13. Respective inet- and outlet chambers 14, 15 are separated by a valve seat assembly 16 which is select- ively opened or closed by a jumper valve 17.
A stuffing box 18 is screwthreadably mounted on the faucet body 11 and is fitted with a screwthreaded faucet stem 19, provided with a coaxial bore (not shown) which is rotated by a handle 20. The valve seat assembly 16 has a bore 21 inter¬ connecting the chambers 14, 15, the bore 21 being surrounded by a peripheral raised annular valve seat 22. The jumper valve 17 has a valve stem 23 extending coaxially from a valve disc 24, the stem 23 being loosely received in the bore in the tap stem 19.
A screwthreaded peg 25 extends coaxially from the underside of the valve disc 24 and is engaged in a central bore 26 formed in the valve washer 27.
Referring to FIG. 2, the valve washer 27, of resiliently flexible polyether plastics material has a central frusto-conical portion 28 surrounded by an annular disc portion 29 which is provided with an annular face 30 adapted to sealably engage the annular valve seat 22, while the frusto-conical portion 28 is adapted to sealably engage the wall of the bore 21 in the valve seat assembly 16. These two portions provide two sealing zones between the valve washer 17 and the valve seat assembly 16.
A third sealing zone is provided by the sealing engagement of the junction 31 of the frusto-conical and annular disc portion 28, 29 of the valve washer 17 with
the junction 32 of the annular valve seat 22 and the bore 21.
Therefore, in use, the valve washer 17 is sealed to the valve seat assembly 16 in three sealing zones to prevent any leaks from developing.
If the annular valve seat 22 or the bore 21, or the junction 31, become worn, effective sealing will still be provided by the two remaining sealing zones between the valve washer seat assembly and leaks will only occur if, and when, all three components become damaged or worn. If the annular face 30 on the valve "washer 17 does become compressed (for example due to over-tightening of the faucet) , an effective seal is still maintained between the valve washer and the valve seat assembly.
FIG. 3 shows a one-piece jumper valve 33 moulded from polyester plastics material. The valve 33 has a stem 34 formed integrally with the valve disc/washer 35. The disc/washer 35 has an annular face 36, to sealably engage the annular valve seat 22, and a central hemi¬ spherical portion 37, to sealably engage the wall of the bore 21. The junction 38 between the annular face 36 and the hemi-spherical portion 37 sealably engages the junction 32 of the faucet in the manner hereinbefore described for junction 31.
If preferred, a washer e.g. of "Delrin" (trade mark) plastics material may be placed on top of the valve disc 24, 35 to protect the upper face of the disc 24, 35 from scuffing or rubbing by the faucet stem 19. The limited comparative testing carried out to date has shown that jumper valves made in accordance with the present invention have many times longer effective life than any of the jumper valves readily available on the market today. The washers 27, 33 may be sold separately as
replacements for the valve washers presently avail¬ able on the market.
For certain applications, thfe frusto-conical portion 28 may have a compound tapered shape, with a reduced degree of taper adjacent the junction 31 to increase the area of that portion which will sealably engage the bore 21 in the valve seat assembly 16.
It will be readily apparent to the skilled addressee that various changes and modifications may be made to the embodiments described and illustrated without departing from the scope of the present invention.
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