An Improved Adjustable Bridge and Damper for Marine or any other kind of Boilers.
Year: 1895

page_text: Date of Application, 5th Mar.,
1895
Complete Specification Left, 4th Dec., 1895–Accepted, 29th Feb., 1898
PROVISIONAL SPECIFICATION.
An Improved Adjustable Bridge and Damper for Marine or any
other kind of Boilers.
We JOHN SMITHYMAN of 30 Angelina Street Cardiff in the County of
Glamorgan Engineer and DAVID OLIVER DAVIES of 35 Talbot Street Cardiff
in the County of Glamorgan Merchant do hereby declare the nature of this
invention to be as follows:-
Our invention relates to especially adapted adjustable bridge and damper and
consists of a fireclay burr with a circular top the same shape as the inside of the
flues. The burr to be raised or lowered by means of a worm and worm wheel
spur pinion and rack or by levers or any other mechanical arrangements suitable
for the purpose. The burr to be worked from a shaft running from the back end
of the fire place to the front of the boiler under the bottom of the fire bars the
front end of the shaft to be carried by a bracket bearing fixed to the front of
the boiler and held in position by a ratchet wheel and pawl and worked by a
spanner from the front end of the boiler. The back end of the shaft to be carried
by a bracket bearing fixed to the back bridge. The levers or wheels for adjusting
the burr to be worked from the end of the shaft inside the combustion chamber.
This invention by raising and regulating the burr above the top of the permanent
bridge in case of the stopping the engines or banking up the fires admits of only
the required quantity of draught to heat the air before entering the tubes thereby
preventing the leaking of the tubes as frequently is the case especially in very
high pressure boilers.
We also prevent the burning of the fire bars and the bearing bars by adjusting
the bridge damper instead of using the ashpit damper which can be entirely done
without.
We also claim that by adjusting the bridge we secure, a far better combustion
and thereby economise the consumption of fuel and prevent to a very great extent
the leaking and the fouling of the tubes when the boiler is in full work.
Dated this Fourth day of March 1895.
JOHN SMITHYMAN.
D. O. DAVIES.
An Improved Adjustable Bridge and Damper for Marine or any
other kind of Boilers.
JOHN SMITHYMAN of 30 Angelina Street Cardiff in the County of Glamorgan
Engineer, and DAVID OLIVER DAVIES, of 35 Talbot Street Cardiff
in the County of Glamorgan Merchant 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 :-
Our invention consists of a new or improved adjustable bridge and damper for
regulating the draught and economising fuel in marine or any other kind of boilers,

page_text: also for preventing the leakage and fouling in the tubes of multitubular boilers and
to a great extent prevent the burning of the fire bars and by adjusting the bridge
we secure a better combustion.
And in order that our said invention may be properly understood and carried
into practical effect we will now proceed to describe the same more particularly
reference being had to the accompanying sheet of drawings and to the letters and
figures marked thereon.
The drawings appended to this Specification represent two modifications or
methods of working the adjustable bridge and damper, one to fold up on hinges
and one to slide vertically.
Fig. 1 is an elevation of the back end of the boiler flue showing the working of
the folding adjustable bridge and damper A which consists of a burr composed
of fire brick asbestos plumbago or any other suitable materials. The adjustable
bridge and damper A is carried by an iron frame B working on hinges CC
which is secured to the top of the back bridge plate D the adjustable bridge and
damper A is opened or closed by link E which is connected to lever F which is
carried by shaft G in bearings HH and worked by worm wheel I driven by worms
on shaft which is carried through the boiler flue on one side under the fire bars
and continued through a bearing in the back bridge plate D into the combustion
chamber to receive the worm J the front end of shaft K is carried by a bracket
bearing L at the front end of the boiler which is bolted to the front dead plate M the
shaft continuing through the bearing of sufficient length to receive a portable
handle N for turning the worm J and worm wheel I for opening or shutting the
adjustable bridge and damper A. as shown in longitudinal section Fig. 3. as
hereinafter to be described.
Fig. 2 is an elevation of the back end of the boiler flue corresponding with
Fig. 1. showing the back end bridge plate before the adjustable bridge and damper
are fixed thereto all marked letters corresponding with Fig. 1 and Fig. 3.
Fig. 3 is a longitudinal_section corresponding to Fig. 1 and Fig. 2 showing the
position of the shaft K and worm J and worm wheel I for working the lever F and
connecting link Ę to iron frame B for carrying the adjustable bridge and damper A
the bracket bearing L bolted to the front dead plate M for carrying the front end
of the shaft K with portable handle N for opening and shutting the adjustable
bridge and damper A all letters marked corresponding with Fig. 1 and Fig. 2.
Fig. 4. is an elevation of the back end of the boiler flue, showing the working of
the raising and falling adjustable bridge and damper O which consists of a burr
composed of firebrick, asbestos plumbago or any other suitable materials, the adjust-
able bridge and damper is kept in position with two guides PP which are bolted to
the back bridge plate Q the adjustable bridge and damper O is carried by a stud R
fastened to same and coupled by a link S which is connected to lever T and is
worked by a shaft U which is carried through the boiler flue on one side under
the fire bars and continued through a bearing in the back bridge plate Q into the
combustion chamber to receive the lever T the front end of the shaft U is carried
by a bracket bearing V which is bolted to the front dead plate W the shaft U
continuing through the bearing V of sufficient length to receive a ratchet wheel X
and squared at the extreme front end to receive a portable, wrench Y for working
the lever T for raising or lowering the adjustable bridge and damper O which is
held in any position required by the Z pawl in the ratchet wheel X as shown in
longitudinal section Fig. 6.
Fig. 5 is an elevation of the back end of the boiler flue showing the adjustable
bridge and damper O before the guides P P are fixed thereto and showing the
position of the stud pin R link S lever T and shaft U as shown in longitudinal
section Fig. 6.
Fig. 6. is a longitudinal section corresponding to Fig. 4 and Fig. 5 showing the
position of the shaft U for working the lever T connected to link S unto stud R
for working the adjustable bridge and damper O up and down-the front end of
the shaft U carried in a bracket bearing V bolted to the front dead plate W this

page_text: shaft U continuing through the bearing V of sufficient length to receive a ratchet
wheel X and squared at the extreme end to receive a portable wrench Y for
working the adjustable bridge and damper O and held in any position required by
the pawl Z into the ratchet wheel X.
Fig. 7. is an elevation of portable wrench Y for turning the shaft K as shown
in Fig. 6.
Fig. 8. is an elevation of ratchet wheel and pawl X for holding the adjustable
bridge and damper O in any position required as shown in Fig. 6.
Fig. 9 is a plan of the adjustable bridge and damper O showing the position of
the guides P.P as shown in elevation in Fig. 4.
Having now described and particularly ascertained the nature of our said inven-
tion, and in what manner the same is or may be used and carried into practical effect
we desire it to be understood that we do not confine ourselves to the precise details of
arrangements that are herein before described as the same may be varied without
departing from the essential features of our improvement but what we do claim
as our invention and desire to have protected by Letters Patent is
The use of a new or improved adjustable bridge or damper for regulating the
draught, and economising fuel in marine or any other kind of boilers, that we
consider and believe it to be new and therefore claim as hereinbefore described
and shown in the accompanying drawings.
In witness thereof we the said John Smithyman and David Oliver Davies
have hereunto set our hand and seal.
D
0.1002
J. SMITHYMAN.
D. O. DAVIES.