CERTAIN IMPROVEMENTS IN THE SAID JOHN DICKINSON'S PATENT MACHINERY FOR MANUFACTURING PAPER; AND ALSO CERTAIN APPARATUS FOR SEPA- RATING THE KNOTS OR LUMPS FROM PAPER OR PAPER STUFF
Year: 1814

page_text: A.
TO ALL TO WHOM THESE PRESENTS SHALL COME, We, JOHN
DICKINSON and GEORGE DICKINSON, of Nash Mills, in the County of Hertford,
Paper Makers, send greeting.
WHEREAS His most Excellent Majesty King George the Third, did, by
His Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-fourth day of
August, in the fifty-fourth year of His reign, give and grant unto us, the said
John Dickinson and George Dickinson, our exors, adññors, and assigns, His
special licence, full power, sole privilege and authority, that we, the said John
Dickinson and George Dickinson, our exors, admors, and assigns, during the
term of years therein mentioned, should and lawfully might make, use, exercise,
and vend, within England, Wales, and the Town of Berwick-upon-Tweed, our
Invention of "CERTAIN IMPROVEMENTS IN THE SAID JOHN DICKINSON'S PATENT
MACHINERY FOR MANUFACTURING PAPER; AND ALSO CERTAIN APPARATUS FOR SEPA-
RATING THE KNOTS OR LUMPS FROM PAPER OR PAPER STUFF;" in which said Letters
Patent there is contained a proviso that if we, the said John Dickinson and
George Dickinson, or one of us, shall not particularly describe and ascertain the
nature of our said Invention, and in what manner the same is to be performed,
by an instrument in writing under our hands and seals, or under the hand and
seal of one of us, and cause the same to be inrolled in His Majesty's High
Court of Chancery within six calendar months next and immediately after
the date of the said Letters Patent, that then the said Letters Patent, and

page_text: all liberties and advantages whatsoever thereby granted, shall utterly cease,
determine, and become void, as in and by the same, (relation being thereunto
had), may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, we, the said
John Dickinson and George Dickinson, do hereby declare that the nature of
our said Invention, and the manner in which the same is to be performed, are
particularly described and ascertained by the Drawing hereunto annexed
and the following description thereof (that is to say):-
In the first place, with regard to the improvements of John. Dickinson's
Patent Machinery for the Manufacture of Paper, the first improvement consists
in a method of regulating the passage of the water through the cylinder, when
at work in making paper as described in the said John Dickinson's Specification,
inrolled in the High Court of Chancery on the Twenty-first day of November,
One thousand eight hundred and-eleven.--In the annexed Drawing the tube
marked A in the horizontal section of the machine Figure 1 is answerable to
the tube referred to in the above-mentioned former Specification, and marked
G in the Drawing thereto belonging. On each end of it, but within where
the ends of the cylinder work, are fixed two rings B, B, which are turned so
as to be about three eighth of an inch less in diameter than the inside of the
making cylinder. After these rings are fixed on the tube, there is fixed to
them a casing of wood or metal extending from one to the other in a direction
parrallel with the axis, but not projecting beyond the periphery of the
rings B, B, so as to form a segment of a cylinder, of three quarters round or
thereabouts, or, as marked in the Drawing Figure 1, from about C to D.
The effect of this part is that when the machine is at work and the back filled
with pulp, the water which runs through the making cylinder must pass
through the narrow openings of three sixteenths of an inch wide or thereabouts,
which are found at each end between the rings and the inside of the cylinder,
which spaces are calculated to allow a sufficiency of water to pass for making
of paper, but so regulate its passing that it cannot run through too fast when
the uncovered part of the cylinder first enters the pulp.
The next improvement consists in removing the air trough, described in the
said former Specification, out of which the air was pumped, so as to cause a partial
vacuum under that part of the cylinder which was passing over the trough,
and in lieu of it to suck the air from the inside of the cylinder itself by a pair
of air pumps constantly going while the machine is at work, to which a pipe is
led from the inside of the cylinder through the tube A, and the pipe is
marked E in the annexed Drawing. It is to be observed that the orifice of
this pipe should be above the level of the water inside the cylinder.

page_text: The third improvement consists in the application of condensed air to force
the paper off the cylinder at the point where the couching takes place. The
method of doing this is to fix a small trough, F, inside the cylinder between
the rings, exactly parrallel with the axis of cylinder, and as near as possible
below the centre of the couching roll. This trough has a flanch all round it,
shaped so as to correspond with the inside of the cylinder, and the flanch has
leather sewed upon it; and when the trough is fixed in its place the leather is
pressed up against the cylinder, and the cylinder in going round rubs upon it,
but it is necessary to take care that the leather covers the flanch only and not
the opening of the trough.
The air pumps for the suction must be made to act so as to force the
air that they discharge into a receiver, where it accumulates and becomes:
condensed, equal to a pressure of about one pound on the square inch,
and the pressure requires to be regulated by a safety valve through which the.
surplus air may escape. From this condenser a pipe is led into the cylinder
through the tube A, where it is branched, and conveys the air into the
couching trough F, at each end to which the pipe is connected by joining
screws; the pipe is marked G, the joining screws H, H. As the water, during
there is a pipe I led
the working of the machine, accumulates in this trough,
away from the centre of it which opens inside the cylinder, but as near the
bottom as possible through which that water escapes. It is necessary to be
careful that the trough is so fixed that the condensed air has no passage
out of it into the inside of the cylinder, as that would prevent the operation of
the suction.
The fourth improvement relates to the washing of the cylinder while at
work in making paper. For this purpose a pipe K is fixed over the cylinder,
nearly in the situation shewn in Figure I, and parallel with the axis. This
pipe has a slit in the under side of it, from which a jet of water is forced out
upon the surface of the cylinder. Of course clear spring water is best for this
purpose, but it should not be allowed.to mix with the water that runs through
from the pulp; and on that account there is a trough L fixed in the inside of
the cylinder between the rings B, B, with a flanch round it, and the flanch
covered with leather, in the same manner as the other trough; and when in its
place it is intended also to be close up against the inside of the cylinder & must
be as near as possible to the other trough. From this trough there is a
pipe M, also led away through the end of the tube A, and the water which has
passed through the cylinder runs to waste. Between the lower side of the
trough L and the point C there is fixed a piece of wood, the upper side shaped
so as to fit the inside of the cylinder (and when the machine is at work), rubbing

page_text: against it. The purpose of this is to prevent the suction drawing air in through
this part of the surface of the cylinder. In order to allow of these alterations, it
is necessary to have the tube A different from what it is described in the former-
Specification before referred to, where it is marked G, and the use of the pipes
therein marked L, L, L, L, may be given up, and also to have the upper side of
the tube open to allow of the pipes E, G; M, and the water entering. It is also
to be observed that the water which passes for making the paper according to
this plan goes out at one end only where the cock is fixed, and consequently
the tube must be larger in proportion. The three pipes E, G, M, all pass
through the other end, and the tube must be stopped up round them by
stuffing in tow or some other contrivance, in order that, water may not get out,
nor air get into the cylinder through it. The making cylinder is only shewn
in Figure 1, and is distinguished by three arrows which shew the direction of
the motion.
The second part of the said Invention or discovery, viz, the apparatus for
picking paper, we describe as follows, viz' :-
In the annexed Drawing Fig. 3 represents a section of the machine; N, N,
is the frame; O a round reel, on which the paper marked P is reeled as it
comes from the machine, and afterwards brought to this frame to be drawn off.
The paper is first led over the small octagonal roll marked Q, which is covered
with felt, and has a motion in the same direction with the paper of about
three hundred revolutions per minute. It is next led over the straight edge R,
which is fixed to the side of a piece of wood S, and being drawn rather tight
over it, forces the knots to project from the upper side of the paper; it is
afterwards led over the cushions S, S, which are merely pieces of wood rounded
on the upper side, and covered with felt or woollen cloth. The paper is then
reeled on the roll T, which has a motion given to it so that it may draw the
paper at the rate of about forty feet per minute. The motion should be given
by means of a clutch, or some method that will admit of the reel being struck
out and detached when full, and the empty reel being substituted in its place;
but there are so many well known methods of performing this, that it is un-
necessary to give a description. V, V, are two wood brackets, fixed one on each
side of the frame for carrying the cushions and the octagonal roll. The rollers
W, W have each about twenty-four bars of very thin sheet iron in them, as.
shewn in the Drawings and marked X, X, and these rolls are moved round in
the same direction that the paper travels at about the rate of two hundred and.
fifty revolutions per minute, with the extremity of the bars or teeth lightly
brushing the paper, but it is intended that the second roll should touch the
paper rather harder than the first.
In the construction of these rolls it is

page_text: requisite that the edges of the bars should be perfectly straight, and project an
equal distance from the centre, and the top of the cushions should be exactly
parallel with the centre of the rolls, so that the paper may be level and that the
bars may touch along the whole breadth of it. It is requisite to have the
means of raising or lowering the rolls W, W, according as it may be found
expedient to brush the paper with the teeth harder or more lightly. For that
purpose the hearings are on bracket carriages, which are fixed to the frame by
bolts, and have chased mortices. The same effect may be produced by having
the cushions to shift up and down. There are two small guide rolls Y, Y,
which should be fixed in some way that they can be raised or lowered so as to
adjust the friction of the paper. The octagon reel, for reeling the paper upon,
is preferred on account of the angles being obtuse, so that it draws the paper
nearly in an uniform direction over the cushions.
It is well known that in the process of making paper by the machine, the
grit finds its way to the side of the sheet next the wire on which the paper is
made, and the knots usually are found on the upper side. The intent of this
process is to remove the grit by the friction of the small octagonal roll, and to
scratch the knots off by means of the bars in the rolls W, W.
Of course the
method of leading the paper, and the arrangement of the apparatus, admit of
variation; but that above described is thought to be most convenient and
eligible.
In witness whereof, I, the said John Dickinson, have hereunto set