IMPROVEMENT OR IMPROVEMENTS TO BE USED IN THE PROCESS OF MAKING PAPER BY HAND OR BY MACHINERY
Year: 1839

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BRYAN
DONKIN, of Blue Anchor Road, Bermondsey, in the County of Surrey,
Engineer, and Manufacturer of Machines for Making Paper, send greeting.
WHEREAS Her present Majesty Queen Victoria, by Her Letters Patent
under the Great Seal of the United Kingdom of Great Britain and Ireland,
bearing date at Westminster, the Fifth day of September now last past, did
give and grant unto me, the said Bryan Donkin, Her especial licence, full
power, sole privilege and authority, that I, the said Bryan Donkin, my
executors, administrators, and assigns, or such others as I, the said Bryan
Donkin, my executors, administrators, or assigns, should at any time agree
with, and no others, from time to time and at all times thereafter 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, an
Invention communicated to me by a certain person residing abroad, of an
"IMPROVEMENT OR IMPROVEMENTS TO BE USED IN THE PROCESS OF MAKING PAPER BY
HAND OR BY MACHINERY;" in which said Letters Patent there is contained a
proviso obliging me, the said Bryan Donkin, by an instrument in writing
under my hand and seal, particularly to describe and ascertain the nature of
the said Invention, and in what manner the same is to be performed, and to

page_text: cause the same to be inrolled in Her said Majesty's High Court of Chancery
within two calendar months next and immediately after the date of the said
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Bryan Donkin, do hereby declare that the nature of tho said Invention, and
the manner in which the same is to be performed and used, are fully described
and ascertained by the following description thereof, reference at the same
time being had to the annexed Sheet of Drawings, according to the letters or
figures of reference marked thereon, that is to say :-
The said Invention consists in an apparatus to be employed for the purpose
of separating particles of sand or other foreign matter from the pulp or stufl'
intended to be used in making paper. The said apparatus is represented in
the annexed Sheet of Drawings by the four Figures marked Figure 1, Figure 2,
Figure 3, and Figure 4.
Figure 1 is a plan or bird's-eye view of the same, drawn to a scale of one
inch and a half to one foot, with the exception of the holes represented by the
oval-shaped figures, several of which are marked with the letter n; and these
said holes, for the sake of greater distinctness, are drawn to the full size. The
said plan shews the marginal shape of the said holes; and Figure 3 shews a
vertical section taken on the dotted line marked on the plan from o to p, the
said section bisecting five of the said holes, and shewing distinctly the shape of
the bottom and depth of each hole; k, k, h, k, &c. in Figure 1 and Figure 2
is a flat wooden trough, which is divided into three compartments by the two
On the bottom of the said
edge pieces, as shewn in the plan at q, q, and q, q.
box there are laid nine wooden planks or boards with the said holes n, n, n, &c.
made in the upper side of each of the said boards. Each of these boards is
about three feet three inches long, fifteen inches wide, and three quarters of an
inch thick, but no great precision is required in the dimensions of these boards;
those which have just been mentioned, however, are such as have been in actual
use, and have been found effective in separating a great quantity of sand and
other matter from the paper stuff.
It is very well known to paper makers that the quantity of dirt and sand to
be got rid of greatly varies in rags of different qualities, consequently the area
of the said trough, or rather the surface of the boards, with the holes as herein-
before described, should be made larger or smaller as the nature or quality of
the pulp may require. The apparatus having the dimensions herein-before
stated, has been found to answer very well for that quality of stuff of which
the ordinary kinds of writing and printing paper are made. The marginal

page_text: shape of the said holes'n, n, n, &c. may be considerably varied; but after
many experiments with various shapes the one represented in Figure 1 is found
to be the most effective. By referring to the Drawings Figures 1 and 2, it
will be found that there are two parts of the said trough; one at each cud
thereof, marked A and B, which are deeper than that part on which the said
boards lie, as is clearly shewn in Figure 2..
Figure 4 represents an end view of the part B. The pulp, from which the
sand and other substances are to be separated, having been previously made suffi-
ciently thin by the admixture of water, is made to run into the part marked A;
and as the upper surface of the said boards is lower than the edges of tho
said trough, the pulp, after partially filling the part A, will run over the said
hoard a, a, a, b, b, b, and c, c, c, until it arrives at the other end thereof, where
it falls from the boards into the part marked B. From this part the said pulp
is allowed to escape from that end of the said trough into the vat or other
receptacle previously to its being made into paper by hand or by a machine.
Now, as the stream of pulp must flow from one end of the said trough to the
other, that is from A to B, it is requisite that the upper surfaces of the said
boards should have a sufficient degree of inclination in their longitudinal
direction to cause the pulp to flow over them; and it is found that the
boards a, a, a, ought to be from half an inch to an inch lower at e than at f,
as shewn in the section Figure 2; and that the said boards b, b, b, should be
from one quarter of an inch to half an inch lower at g than at h, as is also
shewn in the same Figure 2. When the pulp has arrived at g, it now becomes
necessary to check the velocity of the stream of pulp for the reason now
assigned, namely, that from the peculiar shape and relative position of the
holes, one row with another. the said holes produce a two-fold effect; first,
that of separating the fibres of the pulp, which are always less or more
congregated into flakes, and thus disentangling any foreign matter, such
as particles of dirt, sand, or other substances, which are specifically heavier
than the fibre of the pulp itself; and, secondly, forming a number of reccp-
tacles into which the said sand or other matter may fall when freed from its
previous entanglement; but as various substances in small particles are always
more or less found in paper stuff, differing among themselves in their specific
gravity, it is found that whilst the pulp is passing over the holes of the board
a, a, a, and b, b, b, with the velocity given to it by the aforesaid inclination of
the said boards, the heaviest particles are there intercepted and deposited in
the said holes, and that the lighter particles are still carried forward. In order
therefore to give the said lighter particles sufficient time also to subside, by
lessening the velocity of the stream of pulp, the boards c c, c, are laid from

page_text: half an inch to three quarters of an inch higher at s than at r, in the manner
shown in the Drawing, Figure 2. It will be obvious from what has been
herein-before said that the stream of pulp should be of as uniform a thickness
or depth across the trough as possible, therefore the upper surface of the said
boards should be laid in their transverse direction, without any inclination
whatever. Although the apparatus has herein-before been described as of defi-
nite dimensions, it will often happen that local circumstances will require an
apparatus of different dimensions, in order to make it accommodate itself to
the space where alone it can be fixed. The apparatus hercin-before described
was applied for the purpose herein-before mentioned to a machine of that kind
known in England by the name of Fourdrinier's Patent Machines for making
paper of a large size, namely about fifty-four inches between the deckles.
Hence any person possessing a competent knowledge of the quantity of paper
which such a machine is capable of making in a day will easily determine the
size of a similar apparatus to any other machine calculated to make either a
greater or lesser quantity of paper, as also the size of one fit to be used at a
common vat from which the paper is made by hand. It should here, however,
be remarked that the length of the trough should in no case be diminished
but rather increased, and that the lateral dimensions or the width thereof
ought alone to be altered. In order to prevent the said boards from floating
on the pulp, six or more leaden weights are placed upon them, as shewn
at w, w, w, &c., in Figures 1, 2, and 4. Whenever the holes. in the said
boards become filled with the particles of sand, &c., which has been separated
from the pulp, the said boards may easily be removed from the first trough,
one set at a time, washed, and replaced in a few minutes, without interrupting
the operation of the machine, for from the foregoing description of the con-
struction of the said trough it will be understood that there are three
distinct and separate channels in which the said boards lic, and through each
of which the pulp or paper stuff is made to flow. As often, therefore, as the
said boards require washing the pulp or paper stuff is prevented from running
into any one of the said channels by the use of a small stop-gate, made of
copper or any other fit material, which is made to slide into suitable grooves
made in the sides of the said channels. Thus the three boards in one channel
may be removed, washed, and returned to their places without interrupting the
flowing of the stuff through the other two of the said channels, so that one set
of boards only is out of use at one time. The said stop-gate is shewn at v in
Figure 1 and v in Figure 2; it is shewn in the plan Figure 1, that in the first
transverse row of holes (marked 1st row), each of the said holes is opposite
the space between two holes of the next row (marked 2nd row), and that

page_text: the same relative position of the holes in every consecutive row is preserved
throughout the whole series of rows.
Lastly, I declare that the Invention consists in the employment of an
apparatus (for the purpose herein-before mentioned) similar to that which is
herein-before described, whether made of wood or other fit material, having
similarly shaped holes, and in which the relative position of the said holes is
the same or nearly so, as is shewn in the annexed Sheet of Drawings.
In witness whereof, I, the said Bryan Donkin, have hereunto set my
hand and seal, this First day of November, in the year of our Lord
One thousand eight hundred and thirty-nine.