IMPROVEMENTS IN SCREENS FOR COAL GAS PIPERS
Year: 1871

page_text: LETTERS PATENT to Edward Duffee, of Haverhill, in the State of
Massachusetts,, of the United States of America, for the Invention
of "IMPROVEMENTS IN SCREENS FOR COAL GAS PIPERS,”
"
Scaled the 26th January 1872, and dated the 19th October 1871.
COMPLETE SPECIFICATION filed by the said Edward Duffee at tho
Office of the Commissioners of Patents, with his Petition and
Declaration, on the 19th October 1871, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD.
DUFFEE, of Haverhill, in the State of Massachusetts, of the United
States of America, send greeting.
WHEREAS I am in possession of an Invention for " IMPROVEMENTS,
IN SCREENS FOR COAL GAS PURIFIERS," and have petitioned Her Majesty
to grant unto me, my executors, administrators, and assigns, Her
Royal Letters Patent for the same, and have made solemn Declaration
that I am the true and first Inventor thereof.

page_text: NOW KNOW YE, that I, the said Edward Duffee, do hereby declare
that the following Complete Specification, under my hand and seal, fully
describes and ascertains the nature of the said Invention, and in what
manner the same is to be performed, in and by the following state-
ment:-
✔
My Invention is represented in the accompanying Drawings, of which
Figure 1 denotes a top view, and Figure 2 an end view of a gas screen
constructed in accordance with one form of my Invention; Figure 3 is
also a top view, and Figure 4 an end elevation of a gas screen as made
in another form thereof.
My Invention has reference to that class of screens in which dry lime
is used as a purifying agent, such screens being employed in the ordinary
gas purifying boxes, and arranged in tiers one above another, each of
such boxes being provided with a cover for the insertion and removal of
the screens, and being connected with the body portion by a hydraulic ]
seal. When in use the gas is led from the hydraulic main by means of
an induction pipe into the lower part of the box, and passing upward
through the series of lime charged screens into the upper part of the said
box is conveyed from thence by an eduction pipe to the station meter.
The object of my Invention is to provide a simple, cheap, and durable
screen for such boxes, one which shall be capable of better withstanding
the corrosive action of the lime and the impurities with which the gas is
charged than those formed of wire netting as heretofore employed.
My Invention consists,-
'
First. In constructing the screens of thin strips of wood crossing each
other, and either notched together or interlaced in the form of basket-
work, and supported by a suitablo framework.
:

page_text: In the said Drawings A, B, C, D, denote the four bars constituting
the frame, a and b being cross bars thereof.
*: In carrying out my Invention as shown in Figures 1 and 2 the frame
of the screen is composed of rectangular bars of wood, each of the
bars A and C being formed with circular holes c, c², extending trans-
versely through it and near the ends thereof, the same being to recieve™
cylindrical tenons e, e',ƒƒ, made on the ends of the bars B, D. Each
of these tenons extends somewhat beyond the face of the bar through
which it passes in order to form abutments or shields to protect the
Jooped portions of the strips of wood or ratan reeved through the said
bars from abrasion-and wear. Furthermore, each of the bars A, C, haš
its outer ends extending beyond the face of the bars B, D, a distance a
little greater than the thickness of the strips. to be reeved through the
said bars, the object of such extensions g, g'; h, h³, being to protect the
portions of the interlacing strips reeved through and protruding from
the bars B, D. Through each of the bars of the frame a series of trans-
verse holes are made as well as through the cross bars a and b. Through
these holes thin strips n, n, etc. of wood or rattan are reeved and inter-
laced at right angles, being carried alternately back and forth through
the holes in the frame, and having their ends properly secured to the
frame, the looped portions of the interlacing strips projecting beyond the
outer faces of the bars, as shown in such Figures.
In carrying out my-Invention as shown in Figures 3 and 4 the frame
of the screen is also made of rectangular bars of wood united together
and of the desired shape, but without any projecting tenons or over-
lapping ends; but there is formed in each external or vertical surfaco of
the frame a longitudinal groove i to recieve the looped portions of the
interlacing strips, and allow the same to be imbedded or sunk below
the outer face of the bar through which such strip is recved. The strips
of wood or rattan being interlaced and secured to the frame as beforo
mentioned.
I would remark that instead of long strips of wood or rattan being
used short strips may be employed and notched or matched together,
such strips corresponding with the length and width of the screen frame
and properly secured at their ends thereto. So also, if desirable, the
frame may be made of iron instead of wood.

page_text: Having described my Invention, what I claim is as follows :-
1st. Constructing coal gas screens of thin strips of wood crossing cach
other, and either notched together or interlaced in the form of basket-
work, and supported by a wooden or metallic framework.
-
2d. In a screen composed of. crossed or interlaced thin strips of wood
supported by a wooden framework grooving the outer edge of such
frame, so that the interlacing strips shall be imbedded or sunk below
the surface of such outer edge in manner and for the purpose set
forth.
8d. In a screen made up of crossed or interlaced thin strips reeved 1
through and supported by a wooden framework forming the side bars
with projecting abutments, and the end bars with extensions or their
equivalents in manner and for the purpose set forth.
l In witness whercof, I, the said Edward Duffec, have hereunto
set my hand and seal, this 27th day of September, A.D. 1871.
DNWADD TATTATATATA
1