IMPROVEMENTS IN AND RELATING TO SELF ACTING DAMPERS FOR REGULATING THE DRAUGHT IN BOILER FURNACES
Year: 1884

page_text: We WILLIAM DENT PRIESTMAN and SAMUEL PRIESTMAN, both of Holderness
Foundry, Hull in the County of York, Engineers do hereby declare the nature of
our said Invention for IMPROVEMENTS IN AND RELATING TO SELF ACTING DAMPERS
FOR REGULATING THE DRAUGHT IN BOILER FURNACES to be as follows:-
.
Our Invention has for its object the automatic governing of the draught in
boiler furnaces by an apparatus, which regulates the amount of opening for such
draught, and consists in the following arrangement of parts. Upon a framework
placed on the boiler, or other suitable position we provide a metal chest which is
connected to the boiler and serves as a pressure chest. Within this chest we
provide a piston, or flexible diaphragm which may be of india rubber mounted on
a metal plate, or block the underside of which is provided with a "centre" or
"knife edge" which bears upon a short arm of a bell crank lever, which is mounted
in the frame and under the "centre," or "knife edge." The long arm of this bell
crank lever is provided with a balance weight, or spring and is connected by a
rod, or wire to the damper valve of the boiler furnace. A stop piece is provided to
regalate the amount of motion of the operating mechanism.
The operation of the apparatus is governed by the pressure in the boiler, for
example if the boiler is arranged to work at 40 pounds of steam, the bell crank
lever is weighted so that the pressure on the piston, or flexible diaphragm will
operate the damper valve and so regulate the draught of the furnace and as soon
as the pressure decreases the weight, or spring on the lever causes the damper valvo
to open again. Thus the amount of opening of the damper valve is dependent
upon the pressure in the boiler.
D
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1
11004
WILLIAM DENT PRIESTMAN.
SAMUEL PRIESTMAN.
By Cheesbrough & Royston,
Agents.

page_text: Figure sa part sectional cleation apparatus g
Invention.
Figure 2 is a plan of Figure 1.
Figure 3 shows a modified form of apparatus shown at Figure 1.
Figure 4 is another modification of our apparatus and applied directly to a
damper.
Figure 5 shows our apparatus applied directly to a damper.
It will be seen that an apparatus according to our Invention consists of the
following arrangement of parts connected together and working as herein set forth.
A is a framework placed on the boiler, or in other suitable position convenient
to the damper. B is a metal chest which is connected to the boiler by the pipe C
and which serves as a pressure chest. Within this chest B we provide a piston, or
flexible diaphragm D which may be of india rubber & mounted on a metal block d¹.
On the underside of the block di there is a "centre," or "knife edge "e which bears
upon the short arm f of the bell crank lever F which is fulcrumed in the frame A
at f¹ and under the "centre," or knife edge" e; the long arm f2 of the lever F is
provided with a balance spring H or its equivalent such as a weight and with a
stop h to regulate the stroke. The lever F is connected by a rod J to the lever I
of the damper valve K placed in the flue L of the boiler.
#
The arrangement shown at Figure 3 illustrates the parts arranged with a straight
lever F and a vertical rod J. This form of apparatus can be applied where the
lead to the damper valve is vertical.
In
The arrangement shown at Figure 4, illustrates the parts arranged as in
Figures 1 and 2, but directly connected to the lever I of the damper valve K.
this case the rod J is dispensed with and the lever F is provided with a forked
end f³ which takes over the lever I of the damper valve K.
The arrangement shown at Figure 5 illustrates the piston D of the pressure
chest B connected directly to the lever I of the damper valve K. In this case the
lever F is dispensed with and the connection is formed through the rod J, the
spring H surrounds the rod J, bears on the piston D and is held by the frame A.
The operation of the apparatus is governed by the pressure in the boiler, for
example if the boiler is arranged to work at 40 pounds of steam, the bell crank

page_text: lever is weighted, so that the pressure on the piston, or flexible diaphragm will
operate the damper valve and so regulate the draught of the furnace and as soon as
the pressure decreases, the weight, or spring on the lever causes the damper valve
to open again. Thus the amount of opening of the damper valve is dependent upon
the pressure in the boiler.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed what we claim is
In Self acting Dampers
First The combination of a steam chest (B), a flexible diaphragın piston (D) a
lever connected to a damper valve lever (I) indirectly by a single connecting
bar (J) as in Figures 1, 2, and 3 or directly as in Figure 4, whereby a great
sensitiveness and certainty of action is obtained, as set forth.
Second The combination of a steam chest (B) a flexible diaphragm piston (D)
connected to a damper valve lever (I) directly by a single rod (J) whereby a great
sensitiveness and certainty of action is obtained, as set forth.
Third The construction in combination of the stean chest (B) piston (D)
lever (F) spring or weight (H) rod (J) lever (I) and valve (K) substantially as set
forth and shown at Figures 1, 2 and 3 of the Drawings hereto annexed.
Fourth The construction in combination of the steam chest (B) piston (D)
lever (F) spring (H) lever (I) and valve (K) substantially as set forth and shown
at Figure 4 of the Drawings hereto annexed.
Fifth The construction in combination of the steam chest (B) piston (D) rod (J)
lever (I) and valve (K) substantially as set forth and shown at Figure 5 of the
Drawings hereto annexed.