AN IMPROVED PULP STRAINER
Year: 1833

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WRIGLEY, of Bridge Hall Mills, near Bury, in the County of Lancaster,
Paper Maker, send greeting.
WHEREAS His most Excellent Majesty King William the Fourth, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twentieth day of June, in the third year of His reign, did, for
Himself, His heirs and successors, give and grant unto me, the said Thomas
Wrigley, His especial license, full power, sole privilege and authority, that I, the
said Thomas Wrigley, my exors, adñiors, and assigns, or such others as I, the
said Thomas Wrigley, my exors, admors, 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 "AN IMPROVED PULP STRAINER;" in which said Letters Patent is contained a
proviso that I, the said Thomas Wrigley, shall cause a particular description
of the nature of my said Invention, and in what manner the same is to be per-
formed, 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 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
Thomas Wrigley, do hereby declare the nature of my said Invention to con-

page_text: sist in an improved machine or apparatus for straining and separating the
knots, or lumps, or other extraneous matter from the pulp used in the process
of making paper, the action of which machine keeps that part which I call
the strainer free from the said knots, lumps, or other extraneous matter which
would otherwise clog it, and prevent the passage of the pulp through the slits
or apertures by which the pulp is strained; and in further compliance with
the said proviso, I, the said Thomas Wrigley, do hereby describe the manner
in which my said Invention is to be, performed, by the following description
thereof, reference being had to the Drawing annexed, and to the figures and
letters marked thereon, that is to say :-
DESCRIPTION OF THE DRAWING.
Fig. 1 represents a front elevation of the apparatus as I prefer to con-
struct it, and Fig. 2 a side view of the same.
Fig. 3 is a vertical section taken through the centre of the cylinders, in
order more clearly to shew their internal construction; and it will be as well
here to observe, that similar letters are used to denote similar parts in all the
Figures.
R is the pulp vat or cistern. A is a cylinder twelve inches in diameter
formed of any suitable material, but I prefer gun metal, fixed to standards
and having its sides perforated with a series of long narrow slits or apertures
at equal distances, about one sixteenth of an inch wide, and seventy.in
number, within which is another cylinder having a similar number of corré-
sponding slits or apertures, and of a corresponding width, better shewn in
section at Fig. 3. These cylinders are accurately ground and fitted together,
in order that the inner one may move round without admitting any pulp or
other matter between it and the outer cylinder. B is a piston rod. passing
through a stuffing box N, to which is attached the piston C, which moves
up and down within the cylinder at every revolution of the crank D, without
touching the sides of the cylinder, a space of about one sixteenth of an inch
being left all round to facilitate its action, and prevent the formation of "rolls,"
as they are technically called, in the pulp. At the end of the crank shaft is
fixed the tooth wheel E, geering into a pinion on the shaft of the pulley e
which is driven by a band from any suitable power. F, G, are two pipes
attached to the top and bottom of the cylinder, the former leading from the
space above the piston, and the latter from. the space below the piston
seen more clearly in Fig. 3. These pipes are furnished with stopcocks H
and valves I, opening outwards into a receiving trough, shewn at J, Fig. 2

page_text: These cocks and valves are for the purpose of regulating the quantity of pulp
that is discharged from the cylinder, and perform a most important duty; for
by their being so adjusted that the pulp discharged through these pipes shall
be less than the quantity forced up or down by the action of the piston, it
follows of necessity, that the portion which cannot pass out by the pipes will
be forced back through the slits in the side of the cylinder, thus causing a
reaction of the pulp through the slits or apertures, and thereby forcing away
any knots, fibres, or dirt which would otherwise adhere thereto and clog the
cylinder, which I call the strainer. The slits or apertures in the cylinders
being cut of the largest size required, which will depend upon the quality of
paper to be manufactured, can be diminished or adjusted to the necessary
width by turning the inner cylinder a round a little way, while the outer
cylinder A remains stationary, so as to cause the bars of one cylinder to cross
the slits or apertures of the other, and thus diminish the openings. This will
be more clearly understood by referring to Figs. 5, 6, and 7, in which K, K,
are two pins or studs, which project from a cross bar at the top of the inner
cylinder. These pins or studs pass through short slots in the cover of the
outer cylinder, shewn at Fig. 8, which pins have sliding caps or plates to cover
the slots, so as to prevent them drawing air. The two pins or studs are
connected to two levers, or arms L, L, fixed to a collar M, which embraces
the stuffing box N. O is a screw, having a recess or groove cut around it
for the end of one of the pins to work in, better shewn at Fig. 9; this screw
passes through a guide P; fixed to the cover of the outer cylinder, and is
tapped into a projection Q, also fixed to the cover of the cylinder; and it will
be evident that, by turning the screw O; it will move the pins or studs round
to the extreme length of the slots, and with them the inner cylinder, while
the outer cylinder will remain stationary, and by this means the slits or
openings may be regulated with the greatest accuracy, and of any desired
width, as shewn in the sectional plan of the cylinders at Fig. 7, where it will
seen. that the slits of the inner cylinder are moved round, so as to diminish
the opening for the passage of the pulp to the interior.
be
Fig. 4 is an elevation of the cylinder on a larger scale, in order more clearly
shew its construction.
Fig. 8 is a plan view of the top cover of the strainer, shewing the slots
through which the pins K, K, move backwards and forwards the projec-
tion Q and guide P.
And Fig. 9 is a view of the screw O, shewing the groove or recess for the
pin to work in.

page_text: Having now described the nature and construction of my apparatus, I will
proceed to describe its action:-The pulp, prepared in the usual way for the
manufacture of paper, being supplied to the cistern R, to the level of the top
of the cylinder, motion is communicated to the piston by the means before
described; and by its action up and down within the cylinder producing a
vacuum, will alternately draw in or strain the pulp through the slits or
apertures above and below the piston into the cylinder, at the same time
forcing a portion of the pulp so strained through the pipes F, G, which being
regulated by the cocks or valves so as to emit only a portion of what is forced
up or down by the piston, the remaining portion of the pulp will be forced
back through the slits or apertures into the vat R, carrying with it the knots,
lumps, or other extraneous matter that had previously been drawn to the
outside of the slits or apertures by the vacuum formed in the cylinder, and
which by their gravity will by degrees settle to the bottom of the cistern R,
thereby allowing the free ingress of another portion of pulp, and preventing
the machine becoming clogged and rendered unfit for use.
Now, I consider the essential principle of my Invention to be, the drawing
in by the reciprocating action of a piston within a box or vessel having per-
forated sides, and placed in a pulp vat or cistern, a certain quantity of pulp,
always more than is intended should pass through the delivery pipes or vents
into the receiving trough or supply cistern, so that the superfluous quantity of
pulp drawn in should be again driven out through the straining apertures, for
the purpose of constantly freeing them from the knots brought within them
by the influx of the pulp within the cavity.
And I claim the exclusive use of any machine for straining pulp for paper
making, whether constructed agreeably to the forms and arrangement of the
several parts herein-before described, or otherwise modified as to form an
arrangement of the several parts of such machine or apparatus, which shall
be so constructed as to bring into operation the above-named principle of
keeping free the strainer, by the forced reflux of a portion of the pulp at
intervals through the apertures of the strainer.
In witness whereof, I, the said Thomas Wrigley, have hereunto set my
hand and seal, this Nineteenth day of December, in the year of our
Lord One thousand eight hundred and thirty-three.
THOMAS (L.S.) WRIGLEY.

page_text: AND BE IT REMEMBERED, that on the Nineteenth day of December,
in the year of our Lord 1833, the aforesaid Thomas Wrigley came before our
said Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
5 above written. And also the Specification aforesaid was stamped according to
the tenor of the Statute made for that purpose.
Inrolled the Twentieth day of December, in the year of our Lord One
thousand eight hundred and thirty-three.