IMPROVEMENTS IN PULP ENGINES
Year: 1876

page_text: **
LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of IMPROVEMENTS IN
PULP ENGINES." A communication from abroad by Alvin Gardner, of the
Village of Windsor, in the County of Richmond, and Robert Forsyth, of the
City of Montreal, in the County of Hochelaga, both in the Province of Quebec,
in the Dominion of Canada.
Sealed the 6th April 1877, and dated the 7th November 1876.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 7th November 1876.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN PULP ENGINES." A communication from abroad
by Alvin Gardner, of the Village of Windsor, in the County of Richmond, and
Robert Forsyth, of the City of Montreal, in the County of Hochelaga, both in the
Province of Quebec, in the Dominion of Canada.
The object of this Invention is to produce an apparatus (especially intended to be
used in paper mills) for reducing rags to pulp, which shall be efficient and rapid in
operation, and at the same time have its working parts so arranged as to be easily
repaired and renewed.
The apparatus or machine consists of a box or vat having any desired number of
sides, the bottom of which is inclined toward the centre, in which is formed a well
or sinking, preferably circular or plain, and having tapering sides. In a dovetail
groove in this are placed one set of the cutting knives.
Centrally in the box is arranged a revolving shaft passing down through the
sinking, and driven either from above or below, on this being set a wheel consisting
preferably of an outside ring connected by arms with the hub, and having open
spaces formed in it; or it may be any other kind of disc found suitable. The under
side of this wheel or disc is bevelled off at an angle by preference corresponding
with that of the dished or tapering sides of the well, and in this bevelled edge is
also formed a dovetail groove in which are set a series of cutting knives. The dove-
tail grooves in the well and wheel have at one or more points on their circumference
thoir rims cut away, so as to allow of the knives and intervening keys being taken

page_text: out or put in place. A locking key at each of the openings holds the knives and
"keys tightly in position.
Any usual or suitable device is provided for lifting the shaft and wheel on it, so
as to raise the latter out of the well.
When the machine is at work, the material to be pulped is drawn down through
the openings in the disc, and having been subjected to the action of the knives, is
expelled from the rim, the pulp when thoroughly mixed and prepared being drawn
off through any suitable opening.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 4th
May 1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN PULP ENGINES." A communication from abroad
by Alvin Gardner, of the Village of Windsor, in the County of Richmond, and
Robert Forsyth, of the City of Montreal, in the County of Hochelaga, both in the
Province of Quebec, in the Dominion of Canada.
The said Invention has for its object the production of an apparatus for reducing
rags to pulp, especially intended to be used in paper making, which shall be efficient
and rapid in operation, and at the same time have its working parts so arranged as
to be readily repaired and renewed.
The apparatus consists of a box or vat of a hexagonal form or make, with a
greater or less number of sides, and having the bottom inclined towards the centre,
in which is formed a well or depression, by preference circular in plan, and with
dished or tapering sides in a dovetail groove, in which is placed one set of cutting
knives.
Centrally in the box is arranged a revolving shaft passing down through the well
or depression, and driven either from above or below, on which shaft is mounted a
wheel or disc consisting of an outer ring connected by arms to the hub, and having
open spaces between them. The under side of the wheel or disc is bevelled off to
an angle corresponding to that of the dished or tapering sides of the well, and in
this bevelled edge is formed a dovetail groove containing also a series of cutting
knives, which are set non-radially, so that in revolving over the cutting edges in
the well a shearing motion is given. The dovetail grooves in the well and wheel
have at one or more points in their circumference the substance of the rim cut away,
so as to admit of the knives and intervening keys being inserted in their places, or
removed for sharpening or any other required purpose, a locking key forced in at
each of the openings maintaining the whole of the knives in place.
In order to raise the shaft and with it the wheel out of the well, a lever is pro-
vided pivotted at one end to an arm projecting down from the box, and and having
its other end pivotted to a rod which is arranged so as to be raised and lowered.
When the machine is at work, the material to be pulped is drawn down through
the openings in the wheel, and having been subjected to the action of the knives, is
expelled round the rim, the pulp when thoroughly mixed and prepared being drawn
off through any suitable valve or opening.
And in order that the said Invention may be fully understood I shall now pro-
ceed more particularly to describe the same, and for that purpose shall refer to the
several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings represents a vertical sectional elevation
of the apparatus.
Figure 2 is a sectional plan of the same with the wheel removed.
Figure 3 is a plan of the undan side of the wal

page_text: A is a box or vat which, in the example shewn in the Drawings, is made of a
hexagonal form, but which may have as many. sides as found convenient, the same
having flanges formed on their edges so as to be bolted together, or being secured to
each other by a framework or in any other suitable manner. B is the bottom of
the box, by preference secured to the sides by flanges, and inclining towards the
centre in which is formed a dished well or depression C, as shewn in Figure 1.
D is a vertical shaft passing up through the well or depression C, and rotated by
means of a pulley E, suitable journals or bearings F being provided, in which the
shaft works. Upon this shaft is fixed by keys, or feathers, or in any other suitable
manner, a wheel composed of a rim G, by preference of the section shewn in
Figure 1, and bevelled to an angle to correspond with that of the depression C,
which rim is connected by arms G₁ with the hub G2, such arms being not vertical,
but set at an angle. In the bevelled face of the rim G is formed an annular
groove H, in which are placed knives I, set alternately with the keys K, the dove-
tail edges of the groove retaining them in place.
:
It should be observed that the knives I, for purposes herein-after explained, are
not set radially.
At one or more points on the outer circumference of the groove, as, for example,
at L, the substance of the rim is cut away to the full depth of the groove, so as to
admit of the introduction of the knives I with intervening keys K into their
places, the circle being completed by the insertion of a locking key or keys, which
tighten up the ring of knives and keys, and hold them securely in place.
Similarly, a dovetail groove M is formed in the tapering side of the well C, and
the metal is cut away, as before, at the point or points N, for example, to allow cor-
responding knives O and keys P (in this case set radially) to be inserted therein, a
locking key, as before mentioned, serving to tighten up the ring, and maintain the
knives and keys firmly in place.
In the under side of the arms G¹ are secured knives I', and in corresponding pro-
jections formed on the bottom of the well C knives O¹ are placed.
X, X, are flanges or scrapers formed on the under side of the rim G, and acting
to force the pulp outwards towards the walls of the box A. These may however, in
some cases, be dispensed with, or, on the contrary, be carried out beyond the edge
of the rim, as shewn at X¹ (Figure 1).
The lower end of the shaft D is received into any suitable shoe Q, which rests on
a lever R, one end of which is pivotted to an arm R¹ projecting downwards from
and secured to the box A, its other end being pivotted to a rod S, the upper end of
which passes through a bracket T, and has formed thereon a screw thread to corre-
spond with the thread cut in the centre of a disc, hand nut, or thumb screw U. The
arrangement of a gland and stuffing box, as shewn at V, will assist in maintaining
the shaft D at the height desired.
It should be clearly understood that although the shaft D is represented as being
driven by a pulley and belt placed below the level of the box, that this is by no
means essential, as the shaft may be continued up through the box, and be driven
by toothed gearing, or in any other suitable manner.
W is a door or opening in the bottom of the box, closed by a slide or valve,
through which the pulp when completely operated upon is drawn off.
It will be obvious from the Drawings and the foregoing description that when it
is required to operate the engine, the shaft D and wheel G are raised by the means
provided for that purpose, and the rags to be cut placed in the well or depression C
underneath the wheel, which is lowered upon them. As the wheel G is rotated, the
rags are cut by the knives I and O, the former, from the inclination at which they
are set, passing over the latter at an angle, thus giving a shearing motion and
tending to produce a pulp with a longer fibre, and by this means forming a better
and stronger paper.
The inclination at which the arms are set gives a stronger suction, and tends
to draw down through the wheel the pulp, which is forced out around the rim cen--
trifugally, the circular current being broken up by the angles of the box.

page_text: When the flanges X, X, are used, the engine may be run more slowly, and the
same effect be produced.
When the knives I or O require sharpening or renewal, it is simply necessary to
withdraw the locking key (which is usually so shaped as to facilitate the operation),
when the knives can be readily and expeditiously withdrawn and replaced. On
the other hand, when the knives by use become a little loosened in the ring, all that
is required is to drive the locking key farther, and thus tighten up the ring.
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,-
First. The combination with the box A of the dished depression C and of the
open wheel G, mounted on the shaft D, and arranged to be lifted as desired, all sub-
stantially and for the purposes herein-before described.
Second. The combination of knives I and knives O carried in grooves formed
respectively in the bevelled wheel G and dished depression C, all arranged and
working substantially as and for the purposes herein-before described.
Third: The combination with a disc or ring of a dovetail groove formed therein,
and holding cutting edges or knives introduced into the groove through one or more
openings cut through the rim of the disc or ring, and held in place by a locking key
or keys, substantially as herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my Specification
set my hand and seal, this Second day of May, One thousand eight hundred
and seventy-seven.
J. HENRY JOHNSON. (L.S.)