CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF PAPER
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DICKINSON, of No. 65, Old Bailey, in the City of London, Stationer, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-third day of September, in the eleventh year of
Her reign, for Herself, Her heirs and successors, give and grant unto me,
the said John Dickinson, my executors, administrators, and assigns, Her
especial licence, full power, sole privilege and authority, that I, the said John
Dickinson, my executors, administrators, and assigns, and every of them, by
myself and themselves, or by my and their deputy or deputies, servants or
agents, or such others as I, the said John Dickinson, my executors, adminis-
trators, 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 mentioned, should
and lawfully make, use, exercise, and vend, within England, Wales, and the
Town of Berwick-upon-Tweed, my 'Invention of "CERTAIN IMPROVEMENTS IN
THE MANUFACTURE OF PAPER;" in which said Letters Patent is contained a
proviso obliging me, the said John Dickinson, by an instrument in writing
under my hand and seal, particularly to describe and ascertain the nature of
my said Invention, and in what manner the same is to be performed, and: to
cause the same to be enrolled in Her 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.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
John Dickinson, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, is particularly
described and ascertained in and by the following description thereof, re-
ference being had to the Drawings hereunto annexed, and to the letters and
figures marked thereon (that is to say):-
My first improvement in the manufacture of paper consists in an alteration
in the mode of manufacturing double plate paper, invented by myself, and for
which I formerly,,videlicet, in the year One thousand eight hundred and thirty,
obtained a Patent. And whereas in the mode described in the Specification
of that Patent, and which has, up to the date of my present Patent, been
pursued, the side of the paper, which in the process of manufacture was in
contact with the wired surface of the last of the hollow revolving cylinders
on which the double, paper is made, was subsequently brought into contact
with the metallic surface of the upper roll of the last pair of press rolls, by
which, in the process of the manufacture, the water is squeezed out; the
improvement proposed consists in reversing that mode, and bringing, the
opposite side of the paper into contact with the metallic surface of this press
roll, videlicet, that side of the paper which has not touched the wired surface
of the hollow revolving cylinder on which the paper is made, as above
mentioned. The result of this transposition is that the smoothness and gloss
imparted to that side of the paper which in the manufacturing process of
pressing comes in contact with the uncovered metallic press roll by which the
last and most severe pressure is given, and which same side is in that respect
best adapted for receiving the impression from the engraved plate in printing,
is no longer identical with the side of the paper originally, subjected to the
impression of the woven wire, but the contrary; and this improvement obviates
certain injurious influences on the most delicate parts of engravings, the.cause
of which has very recently been ascertained to result from the imperfectly
obliterated indentation of the woven wire. The mode of, doing this is shewn
in Figure 1 of the Drawing annexed, in which A, A, are, the two revolving
hollow cylinders.on which the paper is made, and from which it is led by the
endless felt, colored, red, and marked w, to B, B, the first revolving pair of
press rolls; and here the paper receives a slight pressure between two endless
felts, videlicet, the one above mentioned, upon which the double paper is
couched or taken up from the two hollow cylinders A, A, on which it is made,
and the other an upper felt, marked a, which revolves round and with the
upper press roll B, and the course and apparatus for stretching which are
shewn in the Drawing. The paper is then detached from the first felt, and

page_text: led upon another endless felt, colored blue, and marked y, to the succeeding
pair of
press rollers c, c, and between these, as between the former pair, a very
slight pressure is given, in order that the paper may still retain so much of its
soft and pulpy state as will not prevent its being led to the third pair of press
rolls E, E, over the guide rolls D, D, D. At the third pair of press rolls,
E, E, the paper receives a more severe pressure than it has been before
subjected to, sufficient to squeeze out as much water as possible without
detriment to the paper; it is then led away to the revolving cylinders heated
by steam, by means of which the remainder of the water is dried out of it,
and the reeling and cutting of the paper succeed in the usual manner. It.is
unnecessary to describe more of the machinery connected with this improve-
ment, because it is the same as is in use at present for making double plate
paper..
.
My next improvement consists in forming plate paper constituted of three
thicknesses. The method of this is shewn in Figure 2 of the annexed
Drawing, in which the cylinders and felts are marked the same as in No. 1.
F is a reel, fitted or covered with a long length of damp paper, made and
wound off at a different machine, and about the same in degree of wetness
that paper is when conducted to the steam cylinders to be dried. The end of
this paper is led into contact with the wet double paper upon the red, or
first felt w, and carried with it through the press rolls B, B, and by. the
pressure of them and the two other pair of press rolls in succession it is made
to adhere sufficiently for use; but it is to be observed, first, that the side of the
paper is drawn off from this upper reel, which comes in contact with the
double paper underneath, and to which it is intended to unite it, should be the
same side which has been in contact with the woven wire of the cylinder
on which it was made, so that when united the wire impression may not be
external; and secondly, that in this process there is no reversal of the motion
of the third pair of press rolls, as in Figure 1,. it being intended that the
paper unwound from the reel shall be the preferable constituent of the united
sheet, and at the same time smoothest, and in all respects best adapted, for
receiving the impression of the engraving.
My last improvement consists in the use of an exhausted air trough, as
shewn in both Drawings under the second felt. This trough has a pipe from
the bottom, of it, communicating with a pair of. double-acting air
pumps, the
draft of which is made to rarify the air in the inside of the trough, and that
leads to a slight atmospheric pressure on the surface of the wet paper and
felt passing over it; and it is to be observed that the pressure should be limited

page_text: to that part traversed by the paper and felt, and therefore the trough must
be made close and air-tight at all other parts, and for that purpose, when the
width of the web of paper does not extend to the ends of the interior of the
trough, some very thin plates of copper or brass may be so placed upon it, or
on the upper side of the felt, as to cover and close up a certain portion at one
or both ends; and if these metallic plates are placed on the outside or upper
surface of the felt, they require to come nearly in contact with the margin of
the paper, and to be hooked or fastened to some fixed part of the machine
frame in such a way that they may cause as little friction as possible on the
surface of the revolving felt. The interior of the trough is furnished length-
ways with metallic rolls, on the upper surface of which the revolving felt is
supported, and these 'rolls having.a bearing at each end revolve with the felt.
Metallic bars might be substituted for these rolls, but they are not in' all
respects so eligible.
Figure 3 is a plan of the trough, the interior length of which should corre
spond to the extreme width of paper which the machine is destined for making.
As this kind of paper is made at a slow rate, the atmospheric pressure need
not often exceed two or three inches head of water. This suction felt trough
is also applicable with advantage to certain parts of the first felt w, videlicet,
between the couching of the first layer of paper upon it and the couching of
the second, and also between the guide roll G and the first pair of press rolls
B, B.
And I claim the exclusive privilege of applying troughs in this way. The
upper surface of any such troughs should be level, transversely of the machine;
but that is not important in the direction that the paper moves, only observing
that they must be so formed that the air pumps can draw off all the water
that drains into them. As this Specification relates to a machine fully de-
scribed' and in general use, it is unnecessary to shew in detail the framing of
the machine, and the mode of giving' motion to the different parts; and of
course the different motions require means of adjusting the rate of going, as is
the case with all other paper machines, and I do not limit the Invention to
this mode of leading the paper for the purpose of reversing the motion, because
it may be done by another but less convenient mode: The reel of paper in
Figure 2, from which the paper is drawn for the purpose of forming the triple
paper, requires an adjustable drag for the purpose of maintaining a proper
degree of tension on the paper. The shape of the suction troughs admits of
considerable variation'; but that of course is. mere matter of. convenience.
The direction of the movement of the different parts is shewn by arrows. The