Improvements in Apparatus for Automatically Regulating the Supply of Feed Water to Water Tube and other Boilers.
Year: 1894

page_text: Date of Application, 30th Mar., 1894
Complete Specification Left, 29th Dec., 1894-Accepted, 9th Feb., 1895
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Automatically Regulating the
Supply of Feed Water to Water Tube and other Boilers.
I, JOHN ISAAC THORNYCROFT, of the Firm of John I. Thornycroft & Co., of
Church Wharf, Chiswick, in the County of Middlesex, Steam Yacht and Launch
Builders, do hereby declare the nature of this invention to be as follows:-
This invention has reference to apparatus for automatically regulating the supply
of feed water to water tube and other boilers, in which the supply of feed water is
governed by the action of the varying water level upon a float or floats arranged
within the boiler and controlling a feed water valve also located within the boiler,
and it has for objects to enable the apparatus to be readily adjusted from time to
time, from the exterior of the boiler, so that a practically constant water level can
be maintained in the boiler with varying rates of steaming; to afford a ready
indication of the height of the water level for which the apparatus is, for the time
being, set; and to construct and arrange the feed valve and its controlling
mechanism in such a way as to avoid as far as possible all friction between the two,
and so that in the event of failure of any part of the valve controlling mechanism,
the valve will automatically move into the open or safety position.
According to one arrangement the feed water valve is controlled by a lever
provided with a float or floats and the position of the fulcrum of which can be
adjusted through suitable mechanism from the exterior of the boiler, so that the
position in which the lever will be caused to close the feed valve through the action
of the float or floats, and consequently the height of the water level in the boiler,
can be varied from time to time to suit requirement. As will be obvious, apparatus
suitable for thus adjusting the fulcrum of the float lever can be variously constructed.
A convenient arrangement for this purpose is as follows:-The float lever is
fulcrummed in the forked arm of a bell crank lever pivotted to a suitable support
within the boiler, it may be to an extension of the feed valve case, and the other
arm of which is connected by a link to a rod that extends through a stuffing box to
the exterior of the boiler and is capable of being moved end ways. For moving it
endways, its outer end is or may be screw-threaded and be provided with a
corresponding screw-threaded sleeve that is mounted to rotate, but not to move
endways, in a bearing secured to the shell of the boiler, and has secured thereon a
wheel or pulley by which it can be readily rotated when it is desired to move the
rod endways for the purpose of operating the bell crank lever and adjusting the
position of the fulcrum of the float lever. To enable the said stuffing box to he
re-packed whilst the boiler is under steam, the inner end of the adjusting rod may
be provided with a valve adapted, by moving the adjusting rod outward, to fit
closely against a correspondingly formed seat formed on an inward extension of the
stuffing box.
In another arrangement instead of moving the fulcrum of the float lever, an
equivalent result is obtained by varying the length of the connection between the
float lever and the feed valve, as for example by making such connection, or part
thereof, in the form of toggle arms the position of which relatively to each other can
be varied when desired from the exterior of the boiler by suitable adjusting
mechanism such as that hereinbefore described.
To afford a ready indication of the height of the water level for which the
apparatus is, for the time being set, there is or may be combined with the adjusting

page_text: mechanism herein before described, an indicating device comprising a fixed scale or
scales and an index or finger that is operated in any suitable way from the
adjusting mechanism, as for example by fixing it to a spirally twisted rod mounted
in suitable bearings and operated by an arm that fits the said spirally twisted rod
after the manner of a nut, and is fixed to the aforesaid screw threaded adjusting
rod. The said twisted rod and arm also serve to prevent rotation of the adjusting
rod.
One arm of the float lever may advantageously be forked to receive the float,
which is pivoted to it, its other arm, which is provided with a balance weight,
being suitably bent to clear the link connecting the bell crank lever with the
aforesaid adjusting rod.
The feed valve, which may advantageously be a double cone valve, nearly
balanced, is arranged to open downward so that in the event of an accident, such
as the falling out of a pin, it will automatically fall by gravity and leave the feed
water inlet or inlets full open.
To reduce friction between the float lever and feed valve to a minimum, the
former has articulated thereto by a ball and socket joint, a pin the upper end
of which is coned and loosely fitted into a conical recess in the lower end of the
valve stem, accidental disconnection of the two being prevented by a pin carried by
the valve stem and extending freely through a hole or slot in the first mentioned
pin.
Feed water regulating apparatus such as described is very desirable in water tube
boilers as above referred to, because the volume of water contained in such boilers
is very limited, and it is specially suitable for boilers such as those described in the
Specifications of my Patents Nos. 1404 of 1885 and 17809 of 1890, and others of a
similar type, as the feed regulating devices can be conveniently placed in the
separator or upper vessel of such boilers.
Dated this 30th day of March 1801
Improvements in Apparatus for Automatically Regulating the
Supply of Feed Water to Water Tube and other Boilers.
I, JOHN ISAAC THORNYCROFT, of the Firm of John I. Thornycroft & Co., of
Church Wharf, Chiswick, in the County of Middlesex, Steam Yacht and Launch
Builders, do hereby declare the nature of this invention and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement:-
This invention has reference to apparatus for automatically regulating the supply
of feed water to water tube and other boilers, in which the supply of feed water is
governed by the action of the varying water level upon a float or floats arranged
within the boiler and controlling a feed water valve also located within the boiler,
and it has for objects to enable the apparatus to be readily adjusted from time to
time, from the exterior of the boiler so that a practically constant water level can
be maintained in the boiler with varying rates of steaming; to afford a ready
indication of the height of the water level for which the apparatus is, for the time
being, set; and to construct and arrange the feed valve and its controlling
mechanism in such a way as to avoid as far as possible, all friction between the
two, and so that in the event of failure of any part of the valve controlling
mechanism, the valve will automatically move into the open or safety position.

page_text: adjusted through suitable mechanism from the exterior of the boiler, so that the
position in which the lever will be caused to close the feed valve through the action
f the float or floats, and consequently the height of the water level in the boiler,
can be varied from time to time to suit requirement.
As will be obvious apparatus suitable for thus adjusting the fulcrum of the float
lever can be variously constructed.
In the accompanying drawings,
Figs. 1 and 2 show respectively in side elevation and plan, one arrangement of
feed water regulating apparatus constructed according to this invention, the
apparatus being represented in Fig. 1, as applied to a water tube boiler, a portion
only of which is shown.
Fig. 3 is an end view of the float and the means for supporting the same.
Fig. 4 is a cross section on the line of Fig. 6;
Fig. 5 a side elevation; and
Fig. 6 a plan, showing the feed valve, float lever and adjacent parts.
Fig. 7 is a cross section on the line y y of Fig. 4.
Fig. 8 is a longitudinal vertical section showing a convenient arrangement of
adjusting mechanism for varying the height of the fulcrum of the float lever.
Fig. 9 is a face view of an indicating device that may advantageously be used
with such adjusting mechanism.
Fig. 10 is a cross section on the line 2 z, of Fig. 4 but showing a different
connection between the valve and float lever.
Figs. 1, 2 and 3 are drawn to a smaller scale than the remaining figures.
1 is a float capable of withstanding considerable external pressure, for which
purpose it may conveniently consist of a tightly closed steel cylinder similar to
those ordinarily used for storing gases under pressure. To it is clamped a divided
ring 2 having trunnions 2 by which it is pivoted in the forked arm 3 of a balanced
float lever provided with trunnions 4 (Fig. 4) by which it is fulcrummed at 5 in the
forked arm 6 of a bell crank lever 6, 6° that is pivoted at 7 to an extension 8ª of a
casting 8 fixed within the steam separator or drum 9 of a water tube boiler, the
arrangement being such that by moving the said bell crank lever 6, 6ª about its
fulcrum 7, the fulcrum 5 of the float lever will be raised or lowered according to
the direction in which the bell crank lever is moved. 2 are lateral extensions of
the ring 2 serving to confine the movements between the float 1 and the forked arm
of the float lever within convenient limits.
A convenient arrangement of mechanism for adjusting the bell crank lever, and
consequently the height of the fulcrum of the float lever, from the exterior of the
boiler, comprises a link 10 (Figs. 1, 2 & 8) that connects the upper longer arm 6ª
of the bell crank lever to an adjusting rod 11, which extends through a stuffing
box 12, fixed to the exterior of the boiler, and is capable of being moved endways.
For moving it end ways, its outer end may conveniently be screw threaded as shown,
and be provided with a correspondingly screw threaded sleeve 13 that is mounted
to rotate, but not to move end ways, in a bearing 14 carried by an extension 12* of
the stuffing box 12. To the sleeve is secured a wheel or pulley 15 by which it can
be readily rotated when it is desired to move the rod 11 endways for the purpose of
operating the bell crank lever and adjusting the position of the fulcrum of the
float lever. In the example shown, the wheel or pulley 15 is formed with a groovel
rim 15ª, so that it can be conveniently turned by an endless rope 16 (or chain) from
a place at which it could not conveniently be directly actuated by hand.
To enable the stuffing box 12 to be re-packed whilst the boiler is under steam,
the inner end of the adjusting rod 11 may be formed with a valve face at 11* that
is adapted, by moving the adjusting rod outward, to fit closely against a correspond-
ingly formed seat 12 on an inward extension 12 of the stuffing box 12.
To afford a ready indication of the height of the water level for which the
apparatus is for the time being set, there is or may be combined with the adjusting

page_text: mechanism hereinbefore described, an indicating device comprising a fixed scale 17.
(or scales) and an index or finger 17" (Figs. 8 and 9) which is operated in any
suitable way from the adjusting mechanism, as for example by fixing it to a spirally
twisted rod 18 mounted in suitable bearings 19 and operated by an arm 20 which
fits the said spirally twisted rod after the manner of a nut, and is fixed to the
longitudinally adjustable rod 11. The rod 18 and arm 20 also serve to prevent
rotation of the adjusting rod.
21 is the feed water valve arranged in a valve case 22 (Fig. 4, 5 & 6) which, in
the example shown, is cast in one with the support 8. The feed valve may
advantageously be constructed as a double cone valve that is nearly balanced, as
shown, and is arranged to control two delivery ports 23 between the supply and
delivery passages 24 and 25 respectively, the valve being arranged to open
downward so that in the event of an accident, such as the falling out or breaking of
either of the pivot or fulcrum pins at 5 or 7, it will automatically fall by gravity
and leave the ports 23 full open. The feed water may be led to and from the
passages 24 and 25 respectively by pipes arranged in any desired manner within
the boiler.
To reduce friction between the float lever 3 and feed valve 21 to a minimum, the
two are connected by means of a pin or link freely jointed to each, but having no
endway's movement in relation to either. In the arrangement shown in Figs. 4 & 5,
a link 26 is articulated to the lever and valve by ball and socket joints at 27 and 28
respectively, the lower ball bearing at 27 having a detachable part 27, and the
upper bearing having a detachable screw threaded bush 28, divided longitudinally
into two parts, one of which is provided with a flange 28 by which it is connected
through a pin 28° to a similar flange 21" on an extension 21 of the feed valve.
the modified arrangement shown in Fig. 10, the float lever 3 has articulated thereto,
by a ball and socket joint at 27, a pin 26 the upper end of which is coned and
loosely fitted into a conical recess 21 in the extension 21 of the valve, accidental
disconnection of the two being prevented by a pin 29 carried by the valve extension
and extending through a hole or slot 30 in the said pin.
In
Figs. 11 and 12 are diagrammatic views illustrating partly in elevation and
partly in vertical section, modified arrangements of feed water regulating apparatus
according to this invention and wherein, instead of moving the fulcrum 5 of the
fluat lever 3, as in the arrangement shown in Figs. 1 to 7 inclusive, an equivalent
result is obtained by varying the length of the connection between the said float
lever and the feed valve. In the example shown for this purpose in Fig. 11, and
in detail in Fig. 11^, the connecting pin 26 is connected to the lever by a pair of
links 26 and is formed with a screw thread, and the feed valve 21 is screwed upon
the said pin after the manner of a nut and is formed with an externally toothed
flange 21 with which gears a long pinion 31 fixed upon a spindle 10 that is
guided in a bearing 8 on the valve case 22 and in led through a stuffing box on th
boiler shell to the exterior of the boiler, where it is provided with a hand wheel or
<quivalent adjusting device. As will be seen the arrangement is such that by
rotating the pinion, the feed valve 21 can be screwed up and down on the pin 26
and the length of connection between the feed valve and float lever thus varied,
from the exterior of the boiler, to suit requirement.
In the modified arrangement shown in Fig. 12, the connection between the feed
valve and float lever is made in the form of a pair of toggle arms 26, 26ª, the
former (26) being jointed to the float lever 3 at 27, and the latter (26) being
connected to the feed valve at 28 by a ball and socket joint as in Fig. 4. The
positions of the said two toggle arms, relatively to each other, and consequently
the length of the connection between the lever and feed valve, can be adjusted
when desired from the exterior of the boiler by connecting their jointed ends by a
link 10 to adjusting mechanism such as that shown in Figs. 1, 2 and 8.
By the construction of apparatus described, it will be seen that the friction
resulting from the use of stuffing boxes and plug cocks or valves, as in boiler feed
regulating apparatus as heretofore constructed, is entirely avoided, so that the

page_text: apparatus is rendered very sensitive and therefore effective in maintaining a
practically constant water level in the boiler in which it is fitted.
Feed water regulating apparatus such as herein before described, is very desirable
in water tube boilers because the volume of water contained in such boilers is very
limited, and it is specially suitable for boilers such as those described in the
Specifications of my Patents Nos. 1404 of 1885 and 17809 of 1890 and others of a
similar type, as the feed regulating devices can be conveniently placed in the steam
separator or upper vessel of such boilers.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed 1 declare that what I
claim is:-
1. Apparatus for automatically regulating the supply of feed water to water
tube and other boilers, wherein the water supply valve is controlled by a lever
that is subject to the action of a float and the position of the fulcrum of which is
capable of being adjusted from time to time from the exterior of the boiler for
the purpose of varying the normal height of the water level in the boiler, or
the rate of supply of feed water to the boiler.
2. Feed water apparatus of the kind specified in the preceding claim, in which
the lever subject to the action of the float is fulcrummed on a second lever
connected with an adjusting rod that extends through a stuffing box to the exterior
of the boiler and is there provided with an adjusting device by operating which
the adjusting rod can be moved endways and the fulcrum of the float lever thereby
raised or lowered.
3. Feed water regulating apparatus of the kind herein referred to in which the
feed valve is located within the boiler and is directly controlled by a balanced
float lever also located within the boiler and provided with adjusting mechanism
whereby the normal extent of opening of the feed water valve and consequently
the rate of water supply to the boiler, can be varied from the exterior of the boiler
to suit the rate of steaming of the boiler, substantially as herein described.
4. A boiler feed water regulating apparatus in which a feed valve, a lever
connected to it, and a float for actuating such lever are so arranged that the length
of the connection between the said lever and the feed valve is made capable of
adjustment and there is combined with such connection adjusting mechanism
capable of being operated from the exterior of the boiler to admit of adjustment
to suit the desired height of the water level in the boiler or the rate of feed.
5. The construction of my improved boiler feed water regulating apparatus with
a feed valve that is approximately balanced, and is arranged to open downward by
gravity so that in the event of accident it will automatically assume the open or
safety position and leave the feed water delivery opening or openings full open.
6. The hereinabove described several arrangements of boiler feed water regulating
apparatus constructed and operating as explained with reference respectively to
and shown in Figs. 1 to 9 inclusive, (or modified according to Fig. 10); in
Figs. 11 and 11^; and in Fig. 12 of the drawings annexed.
Dated this 29th day of December 1894.
JOHN I. THORNYCROFT.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicaut.