HEADWORK MECHANISM
TECHNICAL FIELD
The present subject matter relates to taps of the type where only part of the full
rotation of a tap spindle is necessary to facilitate full opening of the taps (or faucet or
mixer) from a closed condition, usually a quarter turn and, more particularly, relates to a
quarter turn headwork mechanism in the taps.
BACKGROUND
Generally, taps are defined as "a plate or disk, which shuts against water pressure,
when moved by the rotation of a spindle, at a fixed angle to its plane to cover the valve
aperture". Conventional taps require that the handle and its accompanying spindle be
rotated through several revolutions to enable the threaded handle spindle to longitudinally
move to a degree sufficient to open or close the valve structure of the tap. The degree of
longitudinal rotation depends upon the pitch of the threaded engagement between the
handle spindle and a valve body. In some circumstances, the need to rotate the handle
spindle through several revolutions leads to critical issues, particularly in public
lavatories, where members of the general public may be reluctant to, or simply lazy
enough not to, turn the tap fully off. As its consequence, a very substantial volume of
water can be wasted and this must be paid for by the authority providing the public
convenience.
The headworks for such taps are conventionally based on a single thread based
mechanism in which a spindle is rotated through a number of turns to push an elastomeric
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washer against an inlet washer seat of the tap to close the valve. Older designs of
headworks in these single thread based mechanism permit the spindle to rise and fall as it
is rotated to open and close the tap whilst later designs have a non-rising spindle. Other
designs of headworks, hitherto not usually found in ordinary domestic or industrial taps,
use valve components which only have to be relatively rotated through part of a turn to be
opened or closed, there being no movement of a washer towards or away from the inlet
seat. A few known type of part-turn headwork are full rotation, a quarter- rotation, halfrotation,
and the like. In particular, the full rotation corresponds to a 360 degree rotation
of the valve spindle mechanism. Similarly, 180 and 90 degrees of rotations correspond to
the half and a quarter rotation of the valve spindle mechanism respectively.
Operationally, the half rotation of the valve spindle mechanism includes the screw thread
based mechanism in which two parallel threads move the valve upwards and downwards
but without the rotation of valve and a half rotation completes opening and closing of a
tap.
A few other known and relevant type of part-turn headworks include a half-turn
or quarter-turn ceramic disc headwork and it has been established that these headworks
have considerable advantages in use over the above described screw-down headwork.
Here, the headwork uses two ceramic discs rather than screw thread based mechanism. In
particular, here one of the discs is stationary and other one rotates clockwise or
anticlockwise for opening the valve. Operationally, a half rotation of the valve spindle
mechanism completes the opening and closing of the tap. The working principle in
quarter rotation is also similar to the half rotation as discussed in the preceding lines. The
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only difference is that the opening and closing of valve is completed in quarter rotations
of the valve spindle mechanism. However, even the ceramic discs employed in such
headwork mechanism tend to get wear and tear in long run, which subsequently cause the
taps to leak. Further, such ceramic disc taps are relatively expensive and suffer from a
number of other operational disadvantages. In particular, they can sometimes lock up
especially with high water pressures and are also subjected to problems with grit or dirt
being present in the water.
Accordingly, there is a need for inexpensive taps which can significantly reduce
the wear and tear in the headwork mechanisms, thereby enhancing the efficiency and life
of the taps. Additionally, there is an utmost need to incorporate improved headwork
mechanism to facilitate leak proof taps.
SUMMARY
It is an object of the present subject matter to provide taps incorporating a
headwork mechanism with quarter rotation (90 degrees).
It is another object of the present subject matter to provide the taps with a screw
based mechanism provided with four parallel threads.
It is yet another object of the present subject matter to provide the taps with a
bonnet to accommodate a spindle and a valve placed below the spindle.
It is yet another object of the present subject matter to ensure a perfect quarter
rotation (90 degrees) of the headwork mechanism.
It is yet another object of the present subject matter to ensure a swift movement of
the valves without any wear and tear in the taps.
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It is a further object of the present subject matter to overcome the drawbacks of
leakage of taps leading to a dripping sound from the washrooms.
It is still further object of the present subject matter to achieve efficient, longlasting
and inexpensive taps.
The present subject matter relates to a headwork mechanism for a tap. The
headwork mechanism includes a spindle having parallel threads, a valve having parallel
threads such that the spindle is engaged with the valve via said parallel threads and a
stopper configured to allow rotation of the spindle by 90 degrees.
In an embodiment, the spindle and the valve are housed inside a bonnet and the
valve is disposed below the spindle.
In another embodiment, the valve is connected with a seat washer.
In yet another embodiment, the spindle is rotated in clockwise direction to move
the valve along with the seat washer vertically downwards for closing a passage to block
water flow from the tap.
In yet another embodiment, the spindle is rotated in anti-clockwise direction to lift
the valve along with the seat washer vertically upwards for opening the passage to allow
water flow from the tap.
In yet another embodiment, water is prevented from entering the engaged portion
of the spindle and the valve by providing a U-seal.
In yet another embodiment, a spindle O-ring of the spindle is prevented from
damage during rotation of the spindle by providing a metal washer.
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In yet another embodiment, the spindle is provided with a U-shaped circlip. The
U-shaped circlip is configured to secure the plurality of components of the headwork
mechanism.
In yet another embodiment, the U-shaped circlip is fixed on the stopper. The
stopper is configured to allow quarter rotation of the spindle, i.e. by 90 degrees.
In yet another embodiment, the bonnet is provided with a bonnet O-ring to
prevent leakage through threads of the bonnet and the tap.
BRIEF DESCRIPTION OF DRAWINGS
These and other features, aspects, and advantages of the present invention will
become better understood when the following detailed description is read with reference
to the accompanying drawings in which like characters represent like components
throughout the drawings, wherein:
FIG. 1 illustrates a perspective view of a tap as used in the conventional art.
FIG. 2 illustrates a cross sectional view (of FIG. 1) of the tap provided with a
half rotation (180 degree) of the headwork mechanism.
FIG. 3 illustrates a cross sectional view of the tap provided with another
embodiment of the half rotation (180 degree) of the headwork mechanism.
FIG. 4 illustrates a cross sectional view of the tap provided with a headwork
mechanism structured with two ceramic discs operating with the quarter rotation (90
degree) of the spindle mechanism.
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FIG. 5 illustrates a perspective view of a tap incorporated with the headwork
mechanism with quarter rotation (90 degrees) in accordance with a preferred embodiment
of the present subject matter.
FIG. 6 illustrates a cross sectional view (of FIG. 5) of the tap in accordance with
a preferred embodiment of the present subject matter.
DETAILED DESCRIPTION
The embodiments of the present subject matter are described in detail with reference
to the accompanying drawings. However, the present subject matter is not limited to these
embodiments which are only provided to explain more clearly the present subject matter to
the ordinarily skilled in the art of the present disclosure. In the accompanying drawings, like
reference numerals are used to indicate like components.
The present subject matter relates to taps of the type where only part of the full
rotation of a tap spindle is necessary to facilitate full opening of the tap (or faucet or
mixer) from a closed condition, usually a quarter turn, and more particularly, relates to a
quarter turn headwork mechanism employed in the taps.
The taps, in particular the water taps, are generally used for tapping and supplying
water across the cities. Generally, these water taps are structured with a headwork
mechanism which is defined as the internal working mechanism of the taps. The
headwork mechanism of each tap works in various modes of rotations such as, full
rotation, half rotation, quarter rotation, and the like. These various rotations correspond to
various degree of rotation of the valve spindle mechanism in taps. Such degrees of
rotation include 360 degrees (full rotation), 180 degree (half rotation), 90 degrees (quarter
rotation), and the like.
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FIG. 1 illustrates a perspective view of a tap as present in the conventional arts.
FIG. 2 illustrates a cross sectional view (of FIG. 1) of the tap provided with a half
rotation (180 degree) of the headwork mechanism in which the tap is made up from a
substantially conventional bonnet (3), which is able to be threadably (as a screw thread
mechanism) engaged with a spindle (1). The spindle (1) at its upper end carries splines
(not shown) which engage with the tap handle (not shown). The joining portion between
the spindle (1) and the bonnet (3) is provided with a circlip (2) to retain the components
in assembly. The spindle (1) is further structured with a spindle O-ring (4) and a metal
washer (5). As is represented in Figs. 1 & 2, the lower end of the spindle (1) is placed on
a valve (6) located within the bonnet (3), thus making it a compact spindle valve
mechanism. The spindle (1) and the valve (6) are sealed by a U-seal (8) decreasing the
chances of any kind of leakages therebetween. The valve (6) is advantageously seated on
a seat washer (9) to complete the arrangement of the mechanism. During the supply of
water through water taps, the valve (6) is able to move on the threads (single thread in
360 degrees rotation) of the screw thread mechanism, but is prevented from rotation
about the longitudinal axis of the spindle (1).
FIG. 3 illustrates a cross sectional view of a tap provided with another
embodiment of the half rotation (180 degree) of the headwork mechanism in which the
tap is provided with a headwork mechanism structured with two ceramic discs (9, 10)
rather than the screw thread based mechanism. The ceramic discs (9, 10) may be made
from alumina or other ceramic materials, as can be perceived by a person skilled in the
art.
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The two ceramic discs (9, 10) are arranged coaxially to the spindle (1) arranged
within the bonnet (3), as shown in FIG. 3. The spindle (1) is further structured with two
spindle O-rings of varying dimensions, namely, a small spindle O-ring (4), and a big
spindle O-ring (7). In particular, the ceramic discs (9, 10) are positioned between the
spindle O-ring and seat washer (11). During the supply of water through the tap, one of
the two discs (10) remains stationary, whereas the other one (9) rotates (clockwise or
anticlockwise) for opening the tap. Therefore, a half rotation of spindle mechanism
completes the opening and closing of taps.
FIG. 4 illustrates a cross sectional view of the tap provided with a headwork
mechanism structured with two ceramic discs (9, 10) operating with the quarter rotation
(90 degree) of the spindle mechanism. The tap is also provided with a ceramic disc
gripper (8) placed between the ceramic rotating disc (9) and the spindle O-ring (7), in a
different embodiment of the conventional art, as represented in FIG. 4.
FIG. 5 illustrates a perspective view of a water tap incorporated with the
headwork mechanism operating with quarter rotation (90 degrees) in accordance with a
preferred embodiment of the present subject matter. FIG. 6 shows the cross sectional
view (of FIG. 5) of the tap which is based on the screw based mechanism provided with
four parallel threads, in an embodiment of the present subject matter. The tap includes a
bonnet (3) to accommodate a spindle (1) and a valve (7) placed below the spindle (1).
The clockwise rotation of the spindle (1) closes the valve (7) and anticlockwise rotation
of the spindle (1) opens the valve (7).
According to an embodiment of the present subject matter, the spindle (1) when
rotated in a clockwise direction, the male parallel threads on the spindle (1) rotates. The
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male parallel threads are synchronized with the female parallel threads in the valve (7).
The rotation of the spindle (1) causes the valve (7) with a washer (10) to move vertically
downwards, thereby closing the water passage of the tap.
Also, when the spindle (1) is rotated in an anti-clockwise direction, it causes the
valve (7) along with the washer (10) to lift vertically upwards, thereby opening a passage
to allow water flow from the tap.
It is in accordance to an embodiment of the present subject matter that there is
provided a U-seal (9) that traps and prevents the water to reach the operating mechanism
of the spindle (1) and the valve (7). There is also provided a metal washer (6) to prevent
the damage to Spindle O-ring (5) during rotation of the spindle (1), as represented in
FIG. 6. There can be employed any other suitable mechanical means serving the same
purpose as the one’s illustrated in the present subject matter, as can be perceived by a
person skilled in the art and falling within the scope of the present subject matter.
The bonnet (3) is provided with a bonnet O-ring (8) to prevent water leakage
through threads of the bonnet (3) and the tap. The top of the spindle (1) is provided with a
U-shaped circlip (2) to hold the complete mechanism of the tap in its place securely at all
the times. The U-shaped circlip (2) is fixed on a stopper (4) provided to ensure a perfect
quarter turn (90 degrees) rotation to the spindle (1), also assuring for improved lifelong
performance.
The water tap according to the present subject matter advantageously facilitates
the perfect quarter rotation of the headwork mechanism and also ensures a swift
movement of the valve without any wear and tear in the tap. Further, the water tap
according to the present subject matter overcomes the drawbacks of leakage leading to
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dripping sound from the washrooms, as associated with the conventional art.
Additionally, the construction and the mechanism of the water tap as employed in the
present subject matter are entirely conventional and thus, involving low cost.
Furthermore, the present subject matter promises efficient, long-lasting and inexpensive
water taps.
Although the invention has been described with reference to specific
embodiments, this description is not meant to be construed in a limiting sense. Various
modifications of the disclosed embodiments, as well as alternate embodiments of the
invention, will become apparent to persons skilled in the art upon reference to the
description of the invention. It is therefore contemplated that such modifications can be
made without departing from the spirit or scope of the present invention as defined.

WE CLAIM:
1. A headwork mechanism (100) for a tap, the headwork mechanism (100) comprising:
a spindle (1) having parallel threads;
a valve (7) having parallel threads such that the spindle (1) is engaged with the
valve (7) via said parallel threads; and
a stopper (4) configured to allow rotation of the spindle (1) by 90 degrees.
2. The headwork mechanism (100) as claimed in claim 1, wherein the spindle (1) and
the valve (7) are housed inside a bonnet (3), the valve (7) is disposed below the
spindle (1).
3. The headwork mechanism (100) as claimed in claim 1, wherein the valve (7) is
connected with a seat washer (10).
4. The headwork mechanism (100) as claimed in claim 1, wherein the spindle (1) is
rotated in clockwise direction to move the valve (7) along with the seat washer (10)
vertically downwards for closing a passage to block water flow from the tap.
5. The headwork mechanism (100) as claimed in claim 1, wherein the spindle (1) is
rotated in anti-clockwise direction to lift the valve (7) along with the seat washer (10)
vertically upwards for opening the passage to allow water flow from the tap.
6. The headwork mechanism (100) as claimed in claim 1, wherein water is prevented
from entering the engaged portion of the spindle (1) and the valve (7) by providing a
U-seal (9).
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7. The headwork mechanism (100) as claimed in claim 1, wherein a spindle O-ring (5)
of the spindle (1) is prevented from damage during rotation of the spindle (1) by
providing a metal washer (6).
8. The headwork mechanism (100) as claimed in claim 1, wherein the spindle (1) is
provided with a U-shaped circlip (2), the U-shaped circlip (2) is configured to secure
the plurality of components of the headwork mechanism (100).
9. The headwork mechanism (100) as claimed in claim 1, wherein the U-shaped circlip
(2) is fixed on the stopper (4), the stopper (4) is configured to allow quarter rotation
of the spindle (1), i.e. by 90 degrees.
10. The headwork mechanism (100) as claimed in claim 2, wherein the bonnet (3) is
provided with a bonnet O-ring (8) to prevent leakage through threads of the bonnet
(3) and the tap.