IMPROVEMENTS IN APPARATUS FOR CUTTING SLATE-ROLLS."
Year: 1883

page_text: LETTERS PATENT to Owen Thomas of Bangor in the county of Carnarvon
and Richard Griffith Thomas of Menai Bridge in the county of Anglesea for
an Invention of "IMPROVEMENTS IN APPARATUS FOR CUTTING SLATE-ROLLS."
PROVISIONAL SPECIFICATION left by the said Owen Thomas and Richard
Griffith Thomas at the Office of the Commissioners of Patents on the
2nd June 1883.
OWEN THOMAS of Bangor in the County of Carnarvon and RICHARD GRIFFITH
THOMAS of Menai Bridge in the County of Anglesea "IMPROVEMENTS
APPARATUS FOR CUTTING SLATE-ROLLS
IN
In cutting ridge rolls of slate, the method now adopted is to cut them to the
required size and shape which is cylindrical, by means of a planing machine with
travelling bed. This method is not only tedious and slow, requiring the passage
of the tool over the stones several times, but is very liable to break or damage
the stone.
Our invention is designed to form a machine that will cut the rolls to a circular
or cylindrical shape at one operation, and at a second cut the groove required in
the one side before the stone is removed from the machine.
It consists of a tube or barrel carrying a cutter mounted in a headstock or
pedestal of suitable construction, one resembling the headstock of a lathe would
answer the purpose. At one end of this tube or barrel we connect by a series of
slots and screws or other suitable manner, a tempered cutter cylindrical in form,
and provided at the outer rim with saw like teeth.
On the bed of the machine to which the headstock is bolted we place a series of
rollers, on which the block of slate or stone is placed, and is moved towards the
cutter by means of a slide pressing against it, or it may be placed on a slide-rest
and carried along with it. A guard may be attached so as to strike or press
against the waste projections of the stone on the outside of the tube, and thus
remove them as they are formed. Behind the headstock we place a pair of rollers
to hold or secure the roll as it issues from the tube or barrel, after it has been cut

page_text: to shape. These rollers hold the stone and pass it forward over a pair of circular
saws, set one rather in advance of the other, which cut a V or other shaped groove
as may be required. If a V-shaped groove is required, the saws are set at an angle,
and if a rectangular groove is required they are set vertical, and the stone between
the two saw cuts is afterwards cut out with a chisel.
Motion is imparted to the tube or barrel carrying the cutter from any suitable
driver by band or gearing, to a pulley or wheel attached to it at or near the
headstock, preferably placed between the supports.
In addition to the saws at the back of the machine we sometimes place a
revolving rasp, either hollow as in the case of the saw cutter or having an outside
contour corresponding to the groove, so as to give a finer surface to the finished
roll.
We do not confine outselves to the use of one cutter in each machine, but prefer
to have a number placed side by side, six would form a very convenient machine.
In this case we so arrange the tubes and cutters, that they shall project from the
headstock at different lengths, so that when a stone with square ends is presented
to be cut, one cutter only shall at first begin to cut, and the stone not reach the
second until the first one has penetrated about an inch. This enables us to place
the tubes and cutters nearer together, and prevents waste of material and less
cutting as the second cutter enters the groove formed on one side of the roll made
by the first cutter; each subsequent cutter is thus arranged in relation to the one
preceding it. Or if found more convenient each alternate cutter may be placed at
the same distance from the headstock. Thus the first, third, and fifth cutters
would all attack the stone at the same time, and the second, fourth, and sixth
would not operate until the other series had penetrated about an inch. This
arrangement would prevent the tendency of the cutters to work crooked, or out
to the side of the stone where the groove was already cut by the previous cutter
and where resistance was less. Separate rollers and saws are placed at the rear
end of the machine for to operate on the roll issuing from each cutter and tube.
The several roll cutters or tubes carrying the cutters on their ends, are
connected together by gearing, and to enable this to be set as closely as possible
together, we propose to have recesses cast in one tube to correspond with projecting
teeth on the next, the tubes in this case can lie nearly close together.
We do not confine ourselves to this particular arrangement of gearing, as
suitable wheels could be arranged and keyed onto the tubes, or they might each be
driven by separate pulleys or gear wheels placed on their rear ends which might
then project one beyond the other as in the case of the cutters on the other ends.
Nor do we confine ourselves to the exact description of machines herein described,
as the hollow tubular cutter might be otherwise arranged, as also the saws for
cutting the slots, or each might be arranged on separate stands, but the former is
the method that we consider the best.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Owen Thomas and Richard Griffith Thomas in the Great Seal
Patent Office on the 1st December 1883.
OWEN THOMAS of Bangor in the county of Carnarvon and RICHARD GRIFFITH
THOMAS, of Menai Bridge, in the county of Anglesea " IMPROVEMENTS IN
APPARATUS FOR CUTTING SLATE ROLLS
"
In cutting ridge rolls of slate, the method at present generally adopted is to cut
them to the required size and shape (which is cylindrical), by means of a planing
machine with travelling bed. This method is not only tedious and slow, requiring
the passage of the tool over the stones several times, but it is very liable to break
or damage the stone.
Our invention is designed (to form a inachine in which the rolls may at one
operation be cut to a circular or cylindrical shape, and in which at a second the
groove required in one side may be cut before the stone is removed from the
machine.
The slate to be shaped is passed through a revolving tube with a cutter at the
end of the required size, which gives it the cylindrical shape, and the groove is cut
as it emerges from the tube at the other end by a pair or series of circular saws
placed in the path over which the roll passes.
In the annexed drawing is shown a machine made in accordance with our
invention in which three tubes and cutters are shown.
Fig. 1-is a side elevation
Fig 2-plan-and
Fig 3-end elevation, partly in section.
In these A is the framework of the machine, which may be made either of wood
or metal (that shewn being of wood), B bed-plate attached or fixed thereto,
C rollers carried on the bed-plate, upon which the block slate or stone to be shaped
is first placed, E are a series of tubes (these are shewn in the drawings) mounted
in a headstock D, and revolving in journals therein. The ends of these tubes
project at either end of the headstock or journal in which they are carried, and at
one end are fitted with a cutter e, of tempered steel cylindrical in form, and
provided with saw-like teeth on its outer edge. Any suitable coupling device c¹,
adjusted by set-screws or keys, may be employed to connect the cutter with the
tube, and the tube E should be of a length sufficient to guide the cut roll at right
angles with the cutter as it passes through. The enlargement formed by the
coupling e also serves for the purpose of breaking off the corner and other waste
pieces, which are left adhering to the block as the roll passes inside the cutter.
The tubes E and cutters e are caused to revolve, and motion is conveyed to them
through a train of spur gearing F. The tubes are each geared together by the
wheels f, the central one of which is geared to the wheel f', which is driven by
the pulley f placed on the same shaft. G G₁ are rollers between which the slate
rolls pass as they issue from the revolving tubes E, and by which they are held firmly
while the circular saws H cut out a groove on this under side. Each saw makes
a cut in the slate as it passes over. Those in the drawing are shown set obliquely,
so that the two cuts made in the slate roll, when the intermediate piece is removed,
forms a V-shaped groove therein. Should a rectangular groove be required the
saws are set vertical and the intermediate piece afterwards cut out with a chisel.
The saws H are driven by bands from the drum I, which is driven by a strap from
the same source of power as that from which the strap driving the pulley ƒ³
receives motion. C' is a roller provided with flanges c, which guides the blocks of

page_text: slate to the cutters. K is a slide moving on the bed of the machine, which presses
against the blocks of slate and carries them forward to the cutters with a slow
sliding motion. The slide K is drawn forward by a hand or chain, which is
actuated by the shaft L over which several turns are coiled, the rope passes over
a pulley or carrier at the rear end of the machine. Motion is conveyed to the
shaft L from the drum I by worm and worm wheel shaft i¹, and bevel wheels
and l.
:
In addition to the saws at the back of the machine, we sometimes place a
revolving rasp, either hollow, as in the case of the saw cutter, or having an outside
contour corresponding to the groove so as to give a finer surface to the finished
roll.
The mode of operation is as follows:
The
The slate to be made into rolls is first roughly cut into lengths of a thickness
sufficient to cut one roll, and these are placed in the machine on the rollers C, their
ends being passed under the roller C, which guides them to the cutter.
machine being set in motion, the cutters e and tubes E revolve rapidly, the slate
being pressed against them by the slide K. The cut rolls pass through tubes E
and as they issue at the other end are carried by the rollers G G¹ over the
revolving circular saws H, which cut in them a groove either V shaped or
rectangular, as required, after which the finished rolls are removed from the
machine by an attendant.
We have shewn in the drawings, and herein before described, a machine of
very simple construction, as we consider that by so doing our invention is better
and more clearly set forth and described than by shewing a more complicated
machine. But we do not confine ourselves to the exact details herein set forth as
it is capable of being largely modified.
Having now described our invention in the simplest and best mode known to us
of carrying it into effect, we wish it to be understood that what we believe to be
new and desire to protect by Letters Patent is :-
1st. The construction of a machine for cutting slate rolls, with a hollow cylindrical
cutter through which the finished roll passes, substantially as described and
shewn.
2nd. The use of a machine for manufacturing slate rolls with hollow cylindrical
cutters, through which the roll passes, and a series of circular revolving saws so
placed as to cut the required groove in the roll as it issues from the tube of the
cutter, substantially as described and shewn.
3rd. The general arrangement of machine for manufacturing slate rolls, in which
the rolls are at one operation cut into a cylindrical form and at a second the
required groove is cut substantially as described and shewn.
In witness whereof I the said Richard Griffith Thomas for and on behalf of
myself and the said Owen Thomas have hereunto set my hand and seal this
twenty eighth day of November in the year of our Lord one thousand eight
hundred and eighty three.
RICHARD GRIFFITA. INUMAS.
(L.S.)