Fluid handling – Removable valve head and seat unit – Threaded into valve casing
Reexamination Certificate
1999-11-08
2001-02-20
Shaver, Kevin (Department: 3754)
Fluid handling
Removable valve head and seat unit
Threaded into valve casing
C137S614200, C251S129150, C251S264000, C251S284000
Reexamination Certificate
active
06189561
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a valve cartridge for fitting into a valve and, in particular, but not exclusively, to a valve cartridge for fitting into a domestic tap.
BACKGROUND OF THE INVENTION
Domestic taps typically have an inlet which is adapted for coupling to a water pipe, a bulbous body in which is disposed a valve seat and valve cartridge, and an outlet in the form of a spout through which water can flow. The valve cartridge is provided with a stem having a handle located outside the body at one end and a washer located within the body at an opposite end for sealing against the valve seat. By turning on the handle, the stem is rotated about its longitudinal axis so as to axially move within the tap body. To close the tap, the handle is turned in a first direction so as to screw down the stem and push the washer against the valve seat. To open the tap, the handle is turned in the opposite direction and the washer is displaced upward by fluid pressure to allow water to flow through the valve seat and out the outlet.
The main cause of leakage in such taps is due to wear of the washer. This wear is usually caused by over-tightening of the handle and stem which leads to tearing, cutting or fracturing of the washer. Washers are normally loosely held within the bottom of the stem so that the two can rotate relative to each other. However, when the stem is over-tightened, the washer can also turn with the stem to accelerate wear against the valve seat.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a valve cartridge for insertion into a valve, such as a domestic tap, in which the above problems arising from overtightening can be substantially avoided.
According to one aspect of the present invention there is provided a valve cartridge for a valve having a fluid inlet, a fluid outlet, and a valve seat providing fluid communication between said fluid inlet and fluid outlet, said valve cartridge including:
a housing adapted for coupling to said valve, said housing provided with an axially extending first cavity;
a piston movable within said first cavity for controlling flow of fluid through said valve;
a flow chamber provided at one end of said housing and through which said piston can travel, said flow chamber having a first seal for sealing against said valve seat and a piston seal downstream of said first seal against which said piston can seal to prevent flow of fluid through said flow chamber, said flow chamber further including stop means for stopping said piston from moving axially therebeyond the stop means including a plurality of spaced apart lugs formed about the circumference at one end of said flow chamber so as to abut said one end of said housing, said lugs extending radially into said first cavity so as to stop said piston from moving therebeyond, the spaces between adjacent lugs forming openings through which fluid can flow when in transit from said inlet to said outlet, said piston and flow chamber juxtaposed relative to said valve so that the pressure of the fluid acts in a direction tending to force said piston against said piston seal; and,
an actuator for moving said piston axially without rotation between a closed position in which said piston abuts said piston seal with a predetermined pressure to prevent flow of fluid through said flow chamber, and a fully open position in which said piston is displaced from said piston seal and abuts said stop means to provide maximum fluid flow through said flow chamber;
whereby, when said housing is coupled to said valve, said first seal abuts said valve seat and said actuator can be operated to move said piston axially through said cavity between said closed position and said fully open position to control the flow of fluid from said inlet to said outlet.
Preferably said flow chamber is formed separately from said housing and is frictionally coupled to said one end of said housing.
Preferably said one end of said housing is formed with a circumferential rebate for receiving said lugs.
Preferably the outer diameter of said circumferential rebate is smaller than the outer diameter of said lugs so that a press-fit is formed between said circumferential rebate and said lugs to hold said flow chamber to said housing.
Preferably said flow chamber comprises a first part which includes said lugs and said piston seal, and a second part which includes said first seal, said first and second parts being press-fit together.
Preferably said first and second parts define a second cavity therebetween in which a non-return valve is housed for preventing flow of fluid through said flow chamber in the direction from said outlet to said inlet.
Preferably said actuator comprises a solenoid which is coupled to said piston.
Preferably the linear position of said solenoid within said housing can be varied to vary the position of the piston when in the fully opened position to progressively vary the flow of fluid through said valve.
In an alternate embodiment, said actuator comprises a spindle rotatably supported by said housing and extending through said first cavity said spindle coupled to said piston in a manner so that rotation for a predetermined number of revolutions of said spindle in a first sense causes relative axial movement between said piston and said spindle in a first direction whereupon the relative axial position of said spindle and piston remains unchanged in response to further rotation of said spindle in said first sense, and rotation for a predetermined number of revolutions of said spindle in an opposite sense causes relative axial movement between said piston and said spindle in an opposite direction whereupon the relative axial position of said spindle and said piston remains unchanged in response to further rotation of said spindle in said opposite sense.
This embodiment also includes, a coupling means for coupling said spindle to said piston with the piston coupled to said coupling means in a manner so as to allow relative rotation between said piston and said coupling means.
Preferably said valve cartridge further comprises detent means or ratchet mechanism acting between said coupling means and said housing to resist rotation of said coupling means during said predetermined number of revolutions of said spindle.
Preferably said detent means or ratchet mechanism includes a plurality of axially extending grooves formed on a circumferential surface of said first cavity and at least one protrusion coupled to said coupling means for receipt in one of said grooves.
Preferably said coupling means is provided with at least one extending finger on each of which one of said projections is formed.
Preferably said finger adapted to flex in the radial direction.
Preferably said coupling means is further provided with a screw thread for threadingly engaging said spindle.
Preferably said coupling means further includes a circumferential groove for engaging a lip which is formed on and extends partially about the circumference of said piston, thereby facilitating said relative rotation between said piston and said coupling means.
Preferably said coupling means is provided with a circumferential seal disposed between said finger and said groove.
According to another aspect of the present invention there is provided a valve cartridge for a valve having a fluid inlet, a fluid outlet, and a valve seat providing fluid communication between said fluid inlet and fluid outlet, said valve cartridge including:
a housing adapted for coupling to said valve, said housing provided with an axially extending first cavity;
a piston movable within said first cavity for controlling flow of fluid through said valve;
a flow chamber provided at one end of said housing and through which said piston can travel, said flow chamber having a first seal for sealing against said valve seat and a piston seal downstream of said first seal against which said piston can seal to prevent flow of fluid through said flow chamber, said flow chamber further including stop means for stopping said piston from movin
Burke Peter Ashley
Fridlender Charles
Leeming Alan
Bastianelli John
Price Heneveld Cooper DeWitt & Litton
Shaver Kevin
Wavtech Pty. Ltd.
LandOfFree
Valve cartridge for lift valve having the closing pressure... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Valve cartridge for lift valve having the closing pressure..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Valve cartridge for lift valve having the closing pressure... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2559609