IMPROVEMENTS IN THE CONSTRUCTION OF DOORS AND FRAMES FOR CLOSING THE OPENINGS OF FIRE-PLACES, ASH-PITS, FLUES, CHIMNIES, AND CERTAIN RETORTS
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
SYLVESTER, of Great Russell Street, Bloomsbury, Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster the Third day of March, in the third year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said
John Sylvester, Her especial licence, full power, sole privilege and authority,
that I, the said John Sylvester, my exors, adiñors, and assigns, or such others
as I, the said John Sylvester, my exors, adiñors, or assigns, should at any
time agree with, and no others, from time to time and at all times during the
term of years therein expressed, should and lawfully might make, use, exercise,
and vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF DOORS AND FRAMES FOR
CLOSING THE OPENINGS OF FIRE-PLACES, ASH-PITS, FLUES, CHIMNIES, AND CERTAIN
RETORTS;" in which said Letters Patent is contained a proviso, that I, the said
John Sylvester, shall cause a particular description of the nature of my said
Invention, and in what manner the same is to be performed, to be inrolled
in Her said Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more
fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Sylvester, do hereby declare my Invention of "Improvements in the
Construction of Doors and Frames, for Closing the Openings of Fire-places,
Ashpits, Flues, Chimneys, and certain Retorts," to consist,―

page_text: Firstly, in suspending the door against the opening in such a manner that
the tendency of the door to fall with its centre of gravity under its point of
suspension shall press against the frame and close the opening without the aid
of latch other fastening, and thus prevent the passage of air or other matters
between the door and its frame when the inner surface of the door and outer
surface of the frame are truly wrought into plane surfaces meeting each other
and when no considerable internal pressure exists.
Secondly, in providing that by such mode of suspension the door may be in
a condition to be slidden against the face of the door frame to any required
distance for leaving the opening wholly or partially free, the use and intention
of this sliding motion being to clear away any extraneous substances which
might have been deposited against the said surfaces and therefore that the
door may have a better opportunity of seating itself closely against the truly
wrought plane surface of the frame, this sliding motion being in some cases
facilitated by the application of two produced rails continuing the truly wrought
plane surface for the door to slide against in passing from before the opening to
its place of rest while the opening is free.
And thirdly, in the case of certain retorts in which pressure exists to such
a degree that the proportion of weight with which the door may be made con-
veniently to press against the frame or mouth piece by the force of gravity, as
before mentioned, will not be sufficient to keep it close and air-tight, I add
to the door suspended in the manner herein-before described any of the already
known methods of producing a sufficient pressure against the front of the door
to close the opening and keep the closure air-tight.
And I hereby further declare that the manner in which I carry these my
improvements into effect is shewn in four examples by the Drawings hereunto
annexed, and by the description herein-after contained, reference being had to
the letters marked on the Drawings in correspondence with the similar letters
inserted in the description.
DESCRIPTION OF THE DRAWINGS.
Figure 1 represents a front view of a furnace with the fire door and ash-pit
door shewn as suspended from two horizontal bars and partly slidden from
before the openings. Figure 2, a vertical section of the same in the line A, B,
of Figure 1. The same letters of reference indicate the same parts in both
Figures. a, brickwork against which the door frame is secured; b, the door
frame of cast iron; c, the door of cast iron; d, the plane surface of the door frame
against which the plane surface of the door slides; e, rails for elongating the
plane surface of the door frame; f, horizontal bars from which the doors are

page_text: suspended; g, links suspending the doors from the bars; f, the upper eyes of the
links turning and sliding on the bars and the lower ends of the links hinged to
about the middle part of the height of the doors, so that the doors may press
with nearly equal force against the frames both above and below; h, ears to
guide the upper ends of the links and keep them parallel with the side edges
of the ash-pit door; k, the hinges of the links and doors. Figure 3 a front
view of a furnace in which the suspended sliding door is shewn as being made
to move up and down before its openings. Figure 4, side elevation of the same.
Similar letters refer to similar parts in Figures 3 and 4. a, the brickwork ;
6, the door frame; c, the door; d, the plane surface of the door frame;
e, two rails for elongating the plane surface of the door frame; l, a chain
fastened to the upper edge of the door and passing over two pulleys to a
balance weight; m, a pulley working in a plane parallel to the plane of the
truly wrought surface of the door and door frame; n, a vertical pulley from
which the weight depends; p, the weight; q, four clips rivetted on the
door to prevent lateral motion. Figure 5, a front view of a door and frame,
the door being suspended by a pair of hooks catching over a ledge of the frame
so as to allow the removal of the door by merely lifting it from the ledge.
Figure 6, vertical section of the same in the line C, D, of Figure 5. The
letters of reference are the same in Figures 5 and 6. a, brickwork; b, door
frame; c, the door allowing of sufficient sideway sliding to clear the plane
surfaces of dirt; d, the plane surface of the door frame; r, the hooks from
which the door depends; s, the ledge over which the hooks catch. Figure 7,
a front view of a retort door and frame, a mouth picce shewing the door as
suspended by two links against the vertical face of the frame from a horizontal
bar placed behind that vertical plane. Figure 8, a vertical section of the same
in the line E, F, of Figure 7. Similar letters represent similar parts in
Figures 7 and 8. a, brickwork; b, the door frame or mouth piece; c, the
door; d, the plane surface of the door frame; f, a horizontal bar from which
the door is suspended; g, two links fixed by their upper parts to the ends of
the horizontal bar f, the lower ends being hinged to two studs projecting
from the sides of the door near the middle of its height; t, two plummer
blocks in which the bar f turns and has a sufficient degree of sliding
motion to effect the scraping off of any dirt adhering to
the plane
surfaces. These plummer blocks are placed so far behind the plane of the
truly wrought surface as to give a strong pressure of the door against its
frame, the proportion of the pressure depending on the distance of the point of
suspension behind the plane; u, a chain fastened to the door and supposed to
be passed over two pulleys to a balance weight in some convenient situation,

page_text: the intention of this chain and counterbalance being to facilitate the opening
of the door and to hold it open while access is had to the interior.
And I further declare that I disclaim the application of the balance weight
and chain passing over pulleys, shewn in Figures 4 and 5, except in combina-
tion with the suspended door sliding against the truly wrought plane surface
of the frame surrounding the opening. And I disclaim the means of forcibly
holding the door closely against the frame to resist pressure from within a
retort, except in combination with my suspended sliding door. And I dis-
claim the retort and mouth piece, as shewn in Figure 7 and 8.
But I claim the Invention of a door suspended in such a manner that the
tendency of the door to fall with its centre of gravity immediately under its
point of suspension shall cause it to press with a sufficient proportion of its
weight against the door frame to close the opening without the aid of a latch
or other fastening when the inner surface of the door and outer surface of the
frame are truly wrought into plane surfaces, the door being at liberty to be
slidden for a greater or less distance against the frame to clear away any
extraneous substances which may adhere either to the working surface of the
door or to the frame, as herein-before shewn and described.
And I claim the combination of the said suspended doors with any of the
known methods of applying pressure against the outside of the door in case of
certain retors in which the interior pressure is too great to be resisted by the
weight of the door alone.
In witness whereof, I, the said John Sylvester, have hereunto set my
hand and seal this Second day of September, in the year of our Lord
thousand and eight hundred and forty.
JOHN (L.s.)
SYLVESTER.
AND BE IT REMEMBERED, that on the Second day of September, in
the year
of our Lord 1840, the aforesaid John Sylvester came before our said
Lady the Queen in Her Chancery and acknowledged the Specification afore-
soid and all and every thing therein contained and specified in form above