IMPROVEMENTS IN THE APPARATUS FOR REGULATING THE DRAFT IN THE TUBES OF MULTITUBULAR BOILERS
Year: 1860

page_text: LETTERS PATENT to George Fletcher, of Farnham Place, Southwark, in
the County of Surrey, Engineer, for the Invention of "IMPROVEMENTS IN
THE APPARATUS FOR REGULATING THE DRAFT IN THE TUBES OF MULTITUBULAR
BOILERS." A communication from abroad by Donald Skekel and Alex-
ander Skekel. of Demerara.
Sealed the 16th November 1860, and dated the 5th June 1860.
PROVISIONAL SPECIFICATION left by the said George Fletcher at
the Office of the Commissioners of Patents, with his Petition, on the
5th June 1860.
I, GEORGE FLETCHER, of Farnham Place, Southwark, in the County of
Surrey, Engineer, do hereby declare the nature of the said Invention of
"IMPROVEMENTS IN THE APPARATUS FOR REGULATING THE DRAFT IN THE TUBES
OF MULTITUBULAR BOILERS," to be as follows:-
The Invention communicated to me consists in the employment and appli-
cation as a damper to the mouths of tubular boilers, first, of an apparatus
known by mechanics as a Venetian blind; and, secondly, of sliding dampers
for regulating the draft thereof.
The Venetian blind is formed of one or two parts, and consists of a number
of metallic plates, with two pivots at each end. Two of such pivots serve to
fix the plates to an iron frame in which they move, and which frame is fixed
to the boiler end; the other two pivots serve to connect the plates of the
blind to a rod on either side, which enables the whole of the plates to be

page_text: moved together. This blind is fixed immediately against the mouths of the
tubes, and is adjusted and worked by means of two bell-crank levers, to one
of which one of its side rods is connected.
For carrying out the second part of the Invention, I employ a plate with
perforations corresponding with the tube holes in the boiler, working in
grooves or slides, and adjustable by rods and levers, so that the blank spaces
in the plate may cover the tube holes, and the perforations in the plate come
opposite to the spaces between the tubes, and vice versa.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Fletcher in the Great Seal Patent Office on the
3rd December 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
FLETCHER, of Farnham Place, Southwark, in the County of Surrey, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of June, in the year of our Lord One
thousand eight hundred and sixty, in the twenty-third year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said George Fletcher, Her special licence that I, the said George Fletcher,
my executors, administrators, and assigns, or such others as I, the said
George Fletcher, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention of "IMPROVE-
MENTS IN THE APPARATUS FOR REGULATING THE DRAFT IN THE TUBES OF MULTI-
TUBULAR BOILERS," a communication to me from abroad by Donald Skekel and
Alexander Skekel, of Demerara, upon the condition (amongst others) that I,
the said George Fletcher, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Fletcher, do hereby declare
the nature of the said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the follow-
ing statement thereof, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say:-
This Invention, as communicated to me, consists, firstly, in the construction
and application, as a damper to the mouths of tubular boilers, of an apparatus
similar in principle to a Venetian blind, and, secondly, in the application of
sliding dampers for regulating the draft in boiler tubes.
This damper is formed of one or more parts, having a number of metallic
plates, each working on two pivots or centres at each end, two of such pivots
serving to secure the plates to fixed and movable side rods, forming a frame in
which they move, and which frame is fixed to the boiler end, the other two
pivots serving to connect the plates of the damper to a movable rod on either
side, thus enabling the whole of the plates to be moved together. This
damper is fixed immediately against the mouths of the tubes, and is adjusted
and worked by means of a hand wheel attached to a screwed spindle working
through a pedestal, such spindle being formed with a swivel joint, and con-
nected by links to a cross bar attached to the side rods or movable frame of
damper.
To make the first part of the said Invention better understood, I will now
proceed to describe the same by the aid of the annexed Drawing, in which
the same letters of reference indicate similar parts in the figures therein
contained.
Figure 1 is a partial longitudinal section of a multitubular boiler and
smoke box, showing the improved damper applied; Figure 2 is a transverse
section, showing the improved damper applied to the fire tubes of the boiler,
one side being shown open, and the other side shut. A is the boiler; B, the
mud pipe; C, the grating plate; D, Figure 1, shows the smoke-box door in
section; E, the flue leading to chimney; F, F, two plates secured to sides
of damper, to prevent the flame from passing out at the sides. These plates
are secured in their position by angle irons G, G, (better shewn in Figure 2)
at the top end, and by brackets H, H, let into the brickwork at the lower
end. I, in Figure 1, shows a side elevation of the damper, and Figure 2
shews an end elevation of the damper, one half being shut, and the other
half open. This damper consists of a number of metallic plates or paddles
J, J, J, attached on one side to fixed rods K, K, and on the other side to
movable rods L, L, by pivots. The fixed rods K, K, are placed at a small
distance from the face of the boiler A, and are secured in their position in the
following manner :-The two outside fixed rods K, K, are secured at the top
by angle irons G, G, which are bolted to the grating plate C, and which

page_text: connect the rods K, K, to the plates J, J. The centre fixed rod K is made
twice the width of the two fixed rods K, K, to allow each half of the damper
I, to work independently of the other. The centre rod is secured at top to
the angle iron M of the boiler A by the bracket N, and at the bottom by the
bracket O, which is fixed to the mud pipe B by means of stud bolts. P is
a column or pedestal, with a brass bush fitted in it, having a screw thread cut
therein to allow the damper I to be raised or lowered by the hand wheel Q
cand spindle R. S is a swivel joint communicating with the links T, T,
secured to a cross bar U, U, attached to the side rods or movable frame of
damper I.
In carrying out the second part of the Invention, I employ a plate with
perforations corresponding with the tube holes in the boiler working in grooves
or slides, and adjustable by rods and levers, and so arranged that the blank
spaces in the plate may cover the tube holes in the boiler, and the per-
forations in the plate come opposite to the spaces between the tubes, and
vice versa.
Having now described the nature of the Invention communicated to me,
and the manner of carrying the same into effect, I wish it to be understood
that what I claim as new, and intended to be protected by the herein in part
recited Letters Patent, is,
First, the mode of constructing and applying dampers with fixed and
movable rods, having metallic plates or paddles fitted on movable pins,
whereby the tubes of boilers can be effectually damped close to the end of
the boiler, and when the damper is opened, ready access to the tubes for
cleaning may be obtained, as herein-before described and represented in the
accompanying Drawing.
Secondly, the employment of perforated plates working in grooves or slides to
effect the damping of the tubes of tubular boilers, as herein-before described.
In witness whereof, I, the said George Fletcher, have hereto set my
hand and seal, this Third day of December, in the year of our Lord
One thousand eight hundred and sixty.
GEORGE FLETCHER. (L.S.)