MENTS IN PAPER-MAKING APPARATUS."
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by David Smith at the Office of the
Commissioners of Patents on the 5th November 1879.
DAVID SMITH, of Little Eaton, in the County of Derby, Engineer.
MENTS IN PAPER-MAKING APPARATUS."
$5
'IMPROVE-
way from
This Invention has for its object to treat paper pulp or stuff on its
the strainer or knotter to the wire of the paper machine so as to remove or break
up knots, lumps, or hanks, which are apt to form in it at that stage, notwithstanding
the best possible anterior preparation, and which not only render the paper
imperfect but also injure the "wire" and the "felts." The Invention consists in
combining with the usual apparatus, and in place of what is known as the hog vat,
an improved piece of apparatus through which the stuff is passed immediately
before being delivered upon the wire.
The improved apparatus comprises a castiron box or vat of a rectangular form in
plan, and which in one arrangement is placed near the breast roller of the paper
machine. In the box there is a roller or beater placed with its axis horizontal and
parallel to the breast roller but at a lower level. The stuff enters the box by one
or more inlets at the bottom of the side which is innermost or faces the paper
machine, and the beater rotating in the same direction as the breast roller, the
stuff is carried under it and then up between it and the outer side of the box,
which side is at its lower part curved to avoid a corner. The beater is formed with
a number of radial plates having sharp projecting edges; these plates being built
up with interposed wedge-shaped staves, or blocks of wood, or other suitable
material, and bound together by let-in rings at the ends. The beater plates may
be straight or corrugated, or have a helical or inclined form. The stuff passes
between the beater and a set of stationary plates held vertically in a box placed
beneath the beater in a recess formed in the bottom of the main box or vat.
stationary plates are combined with alternate shorter plates so as to present
projecting edges, which are sharpened, the set of plates being shaped so as to present a
general concave surface, which, when the parts are in working adjustment is
concentric or nearly so with the general cylindrical surface of the beater. The
stationary plates are by preference corrugated (as seen in horizontal section), but
they may be made straight with a slight inclination, or with an elbow, so that the
two halves are inclined in opposite directions.
The
It is important to have the distance between the projecting edges of the beater
plates and those of the stationary plates very accurately adjusted, the object being
to have them not in contact but so nearly so as to brush out or break up the knots,

page_text: lumps, or hanks, as the stuff passes through. In one modification the adjustment
is applied to the roller or beater, its end journals being passed through stuffing
boxes which are adjustable upon the ends of the box or vat, whilst the bearings
supporting the roller are fitted with wedges which are movable by screw spindles.
These screw spindles are adjusted simultaneously by means of a hand wheel and
shaft geared to them by bevil wheels. Springs are by preference applied above the
bearings to allow the roller or beater to yield upwards in the event of extra hard
lumps occurring in the stuff. In another modification the box holding the
stationary plates is made adjustable by means of wedges fitted beneath it with
interposed blocks of rubber or other elastic medium to give a yielding character.
Rubber is also interposed between the plate box and the opening or openings in
the bottom of the main vat or box, such rubber maintaining a watertight joint whilst
allowing of the small adjustment that is required.
The beater vat does not require to be as long as the breast roller, but it is fitted
with a top part, which may be of wood, and which is made of the full width required
for the paper machine, whilst it is adjustable as to height upon the castiron box 80
that it may be set to deliver the stuff at the best level.
Instead of placing the improved apparatus or last clearing beater in the manner
hereinbefore described so that the stuff overflows from it directly upon the wire, it
may be placed at the side of the paper machine or in any convenient position, but
in that case the top of the box or vat is by preference closed, and the stuff after
passing the beater is led by, a pipe to the delivering vat at the end of the paper-
machine.