AN IMPROVEMENT OR IMPROVEMENTS IN MACHINERY FOR MAKING OR MANUFACTURING PAPER
Year: 1833

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HARROLD, of Birmingham, in the County of Warwick, Merchant, send
greeting.
WHEREAS His present Majesty King William the Fourth, by His Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Eleventh day of January now last
past, did give and grant unto me, the said William Harrold, His especial licence,
full power, sole privilege and authority, that I, the said William Harrold, my
executors, administrators, and assigns, and such others as I, the said William
Harrold, 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 Foreigner re-
siding abroad, of "AN IMPROVEMENT OR IMPROVEMENTS IN MACHINERY FOR
MAKING OR MANUFACTURING PAPER;" in which said Letters Patent there is
contained a proviso obliging me, the said William Harrold, 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 per-
formed, and cause the same to be inrolled in His said Majesty's High
Court of Chancery within six 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 and at large appear..

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
William Harrold, do hereby declare that the nature of the said Invention,
and the manner in which the same is to be performed, is particularly
described and ascertained by the following description thereof, and by the
Drawings hereunto annexed; that is to say :-
I form a pulp wheel or dresser, which, being placed in the box or vat con-
taining the pulp, is then, by the application of power in the ordinary way,
made to revolve in the direction of the arrow in Fig. 1. The number of
revolutions may be about forty per minute.
Fig. 1 in the accompanying Drawing is an end view of the wheel or
dresser, the opposite end being of the same form, and the two being connected
together by plates of brass or other material. This wheel or dresser is repre-
sented as carrying six dressing plates, to be presently described, but the number
may be varied as may be found convenient. Fig. 2 is a perspective view of
the wheel, shewing the plates which pass from end to end, one half of which
are plain, and the other so perforated or slit as to form the dressing plates
or strainers for the pulp. The plates, which are perforated or slit to form
the strainers, I generally place so that their planes, form radii with the centre
or axis of the wheel, as seen at A, A, A, A, in the Drawing. The plain or
unperforated plates may at their junction with these slit plates at B, B, B, B,
Fig. 1, form a right angle with them, but the form of the plates and the angle
at which they stand may be varied without changing the principle upon which
they operate. Instead of making the plates flat, they may, for example, be
bent so as to form a curve from their exterior. to their interior points' of
junction, as shewn by the dotted lines C, C, Fig. 1. The lines drawn upon
the plates A, A, Fig. 2, represent slits or openings or perforations cut through
those plates, and forming them into strainers, which allow the fine portions of
the pulp to pass through, and arrest the knots or coarser particles. These
openings may differ in width according to the kind of paper to which the
dresser is to be applied; but I sometimes make them so that they. can be
graduated, and the same wheel or dresser answer for every kind required..
This I accomplish by making the plates double, and perforating them so that
when laid upon each other the openings through the two plates shall exactly.
coincide by sliding one plate upon the other by means of a regulating screw
or otherwise. D, Fig. 2, shews. the shaft by which the wheel or dresser may
be made to revolve. One of the heads of the dresser is made to open at E, E;
and through this opening the pulp that has been cleared from the knots and
courser particles escapes, this end revolving in a hoop or collar fixed in the
opening in the side of the vat or chest. in which the dressing is effected. The

page_text: most advantageous way of using this wheel or dresser is, to fix it at such
height in the vat as that when one of the plain or unperforated plates F, F, F, F,
is upwards and horizontal, it shall coincide or nearly so with the line or surface
of the water. The machine, however, will work if entirely immersed, but not
so advantageously. The perforated faces of the wheel or dresser, in its revo-
lutions, meet the fluid pulp, and as they strike against it the finer parts pass
through into the inside of. the dresser, whilst the coarse are arrested, and at
the same time these coarser particles are prevented from accumulating on the
surface of the strainer by the agitation produced by the plates striking against
or upon the fluid. Instead of plates containing slits, a number of bars
fastened side by side, leaving fine slits or openings between them, may be
employed for the same purvose.
What I claim as the Invention, and for which the said Letters Patent have
been obtained, is the use of a revolving wheel or pulp dresser, which carries
the dresser plates or strainers, causing them to strike against the pulp, and
allowing the dressed portion to pass through to the inside of the wheel or
dresser, acting upon the principle or in the manner herein-before described,
whether the same be made in the exact form represented, or in any other
producing the same effect.
In witness whereof, I, the said William Harrold, have hereunto set
my hand and seal, this Fifth day of June, in the year of our Lord
One thousand eight hundred and thirty-three.