IMPROVED MACHINERY FOR CUTTING SLATE MARBLE AND OTHER LIKE MATERIALS "
Year: 1870

page_text: LETTERS PATENT to Henry Edward Curtis, of Llansantffraid, near
Corwen, North Wales, Engineer, for the Invention of "IMPROVED
MACHINERY FOR CUTTING SLATE MARBLE AND OTHER LIKE MATERIALS "
PROVISIONAL SPECIFICATION left by the said Henry Edward Curtis
at the Office of the Commissioners of Patents, with his Petition,
on the 29th April 1870.
I, HENRY EDWARD CURTIS, of Llansantffraid, near Corwen, North
Wales, Engineer, do hereby declare the nature of the said Invention for
"IMPROVED MACHINERY FOR
CUTTING SLATE, MARBLE, AND OTHER LIKE
MATERIALS," to be as follows:-
The object of the Invention is to divide and square up slabs of slate,
stone, and marble, and also to cut mouldings on and groove and dovetail
slabs, blocks, and pieces of such materials in an economical and efficient
manner. These operations I effect by the use of variously formed tools
which follow each other in the same line of cut and effectually prevent
the binding of the tools in the work. The work to be operated upon is

page_text: mounted on a traversing table which slides on V's formed on the bed of
the machine, and it is actuated by racks and pinions in connection with
a reversing motion arrangement. At the opposite sides of the machine.
are standards which form vertical guides for a transverse sliding frame.
This frame carries the tool holders, and it is fitted with a traversing
screw for adjusting the tool holders to any desired position over the
work. The dividing or grooving tools are carried by two pairs of holders
which are hinged to opposite sides of two blocks carried by the
transverse frame. One of these blocks may be a fixture, the other being
adjustable to allow of the tools it carries being adjusted relatively to
those of the fixed block. The transverse frame may also carry a holder
for planing tools. This transverse frame is raised and lowered by means
of vertical screws working in tapped lugs projecting from the ends of
the frame and driven by a pawl and ratchet motion transmitted thereto
through suitable gearing mounted on the cross head of the machine,
the pawl being set in action through stops carried by the traversing.
table.
The machine is designed to cut at both the forward and backward
traverse of the table, and for this purpose it is provided with a double set
of cutters arranged in reversed positions and on opposite sides of the
transverse frame. Each tool holder carries a series of cutters, say seven,
arranged in the same line, but the foremost cutter raised the highest and
the rearmost the lowest. The cutting edge of the first I make concave,
the second straight, and the third convex. These I repeat in the order
given, finishing with a concave cutter. This order I prefer as a good
clearance is thereby obtained, but it may be varied somewhat in practice.
For the cutting of mouldings special forms of tools will of course be
required. As the work is presented to the cutting edges of the
suspended tools it will be entered by the tools in succession, and in
travelling past these tools it will move under the other set designed to
cut when the work is moving in the opposite direction. These tools by
reason of their being carried by hinged holders will ride on the work and
drop into position for action so soon as the work has passed from under
them. The tools will have an independent adjustment in their holders
to suit the material in hand. The reversing of the table is. rendered
automatic in any well-known manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Edward Curtis in the Great Seal Patent
Office on the 28th October 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
EDWARD CURTIS, of Llansantffraid, near Corwen, North Wales, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of April, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Henry Edward Curtis, Her special licence
that I, the said Henry Edward Curtis, my executors, administrators,
and assigns, or such others as I, the said Henry Edward Curtis, my
executors, administrators, and assigns, should at any time agree with
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for " IMPROVED
MACHINERY FOR CUTTING SLATE, MARBLE, AND OTHER LIKE MATERIALS," upon
the condition (amongst others) that I, the said Henry Edward Curtis,
my exccutors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Edward Curtis, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the Drawing
hereunto annexed, and to the letters and figures marked thereon (that is
to say) :—
The object of this Invention is to divide and square up slabs of slate,
stone, and marble, and also to cut mouldings on and groove and dovetail
slabs, blocks, and picces of such materials in an economical and efficient
These operations I effect by the use of sets of variously formed
tools of the chisel type, which tools when in action follow each other in the
manner.

page_text: same line of cut, and effectually prevent the binding of the tools in the
work. The grooving or dividing tools depend from hinged frames which
overhang the work, and by an automatic feed motion cause the tools to
follow up their successive cuts until the slab of slate or stone is divided,
or the groove or moulding that is being formed therein is completed.
The work to be operated upon is mounted on a traversing table which
slides on A guides formed on the bed of the machine and which traverses
the work under the action of the tools.
In the accompanying Drawing Fig. 1 is a side elevation of my
improved machine, and Fig. 2 is a front elevation of the same.
A, A, is the bed of the machine fitted with A guides to receive the
traversing table B. On the under side of this table are secured parallel
racks C extending from end to end thereof, and in gear with these racks
are pinions D keyed to a transverse shaft D¹ mounted in suitable bearings.
This shaft D¹ carries at one end thereof a spur wheel D³ which gears
into a spur pinion D³ keyed on the driving pulley shaft E, which
receives rotary motion alternately in opposite directions from the driving
bands and pulleys E¹, E³, and thus communicates a to and fro traverse
motion to the table B. F is a slab of slate or stone made fast to the
traversing table B for the purpose, say, of having its ends squared.
To effect this object the cutting tools are required to be brought to act
on the slab near its extremities. At opposite sides of the machine and
near the middle of its length are standards A' which form vertical
guides for a traversing frame G. This frame carries the tool holders,
and it is fitted with a traversing screw G³ for adjusting the tool holders
to any desired position over the work. The dividing or grooving tools
are carried by two pairs of holders H, H', H2, H³, which are hinged to
opposite sides of two blocks I, I', carried by the transverse frame. One
of these blocks may be a fixture, the other being adjustable to allow of
the tools it carries being adjusted relatively to those of the fixed block.
The traverse frame may also carry a holder for planing tools, a block I*
being provided for that purpose. The lateral motion requisite for
adjusting the block I' relatively to the block I, and for giving the traverse
motion to the block I* (which carries the planing tools) for the purpose
of passing the planing tools over the whole surface intended to be planed,
is effected by the screw shaft G' which has its bearings in the ends of
the frame G, and is turned by a winch handle G³. The blocks I',I*, are
provided with half nuts which fit into the thread of the screw G', and

page_text: between the slotted
These excentrics are
thus receive a traverse motion therefrom. This arrangement is shewn in
partial transverse section at Fig. 3, and in partial longitudinal sections
at Figures 4 and 5, the former of which represents the half nut in gear
with the screw shaft G¹, and the latter the half nut out of gear. In order
to lift these half nuts into gear with their screw shaft and to drop
them out of gear when desired, I form the half nuts i with slotted lugs,
and through these lugs I pass a shaft, having its bearings in the ends
of the frame G. This shaft passes also through bracket bearings *,
carried by the blocks I³, I*, and upon the shaft
lugs of the half screw, I mount excentrics 23.
made to slide on the shaft to enable them to follow the movement of
their respective blocks I', I*, and for this purpose the shaft is grooved
from end to end to receive a projection from the excentrics.. A winch
handle, see Fig. 2, is used to impart an axial motion to this shaft, by
which means one or other of the excentrics will be thrown into action
and caused to lift its half nut into gear with the screw shaft G¹. When
this is effected it will be obvious that the turning of the screw shaft G¹
will cause the traverse of that block which has its half nut thrown up
into gear with the screw shaft, the other block remaining quiescent by
reason of its half nut being dropped out of gear with the screw shaft.
The traverse frame G with its blocks and tool holders is raised and
lowered by means of vertical screws G³ pendent from the cross head A'
of the machine and capable of turning in bearings fitted in the cross
head. These pendent screws work through tapped lugs projecting from
the opposite ends of the frame G. The screws G³ carry at their upper
ends bevil pinions into which gear bevil wheels mounted on the opposite
ends of a transverse shaft K which turns in bearings provided for it on
the cross head. As therefore this shaft K is rotated it will turn the screws
and cause them to raise or lower the frame G with the tool holders as
desired. In order to ensure the tools following up the progress of the
work the descent of the frame G is made automatic, this is effected in
the following manner :-On one side of the table B are fitted two stops
b, b', which are intended as the table comes to the end of its stroke to
strike on one or other of a pair of tappets d, d', fitted to a short rock
shaft D' in line with the shaft D¹. Keyed to the outer end of this rock
shaft is a rock lever L which is slotted at one end to receive a coupling
pin which connects it through a link rod L' with a slotted lever L' hung
upon a stud axle M carried by the cross head A². This lever L' carries

page_text: a pawle which operates upon a wheel M' in gear with a pinion K¹ keyed
to the extremity of the shaft K. It will now be understood that when
by the traverse of the table B the work has been passed under the
cutters the stop 6 will strike the tappet d on the shaft D' and cause
the lever L on that shaft through the link rod L' and lever L to lift the
pawle and move the wheel M' a portion of a revolution, which motion
will be communicated through the gearing on the shaft K to the screws
G³, and thus the tool holders will be caused to approach nearer to the
work as the cutting operation proceeds. On the return traverse of the
table the stop ¹ missing the depressed tappet d will strike the tappet d',
and thereby restore the lever L to its former position, at the same time
drawing down the pawl to the position for repeating its action on the
wheel M¹.
By reference to the Drawing it will be seen that the machine is
designed to cut at both the forward and backward traverse of the table,
and for this purpose it is provided with a double set of cutters arranged
in reversed positions and on opposite sides of the transverse frame.
Each tool holder carries a series of cutters (say six) arranged in the same
line but at different levels, the foremost cutter standing at the highest,
and the rearmost at the lowest level. When doing plain work, as
grooving or cutting slabs, I make the cutting edge of the first tool
concave, the second straight, and the third convex (as shewn in the
diagrams set opposite the tools in Fig. 1), and these I may repeat in the
order given.
This order I generally prefer as a good clearance is
thereby obtained, but it may be varied somewhat in practice. For the
cutting of mouldings special forms of tools will of course be required.
As the work is presented to the cutting edges of the suspended tools it
will be entered by the tools in succession, and in travelling past these
tools it will move under the other set designed to cut when the work is
moving in the opposite direction. These tools by reason of their being
carried by hinged holders will ride on the work and drop into position
for action so soon as the work has passed from under them. In order to
adjust the angle of inclination of the cut of the groups of tools the tool
holders are caused to bear at back upon excentrics N mounted on the
standards A¹. By turning these excentrics either of the holders may
be tipped so as to throw their tools out of action, or their drop may be
adjusted to the greatest nicety. The tools will severally have an
independent adjustment to suit the material in hand.

page_text: Having now set forth the nature of my Invention for " Improved
Machinery for Cutting Slate, Marble, and other like Materials," and
explained the manner of carrying the same into effect, I wish it to
be understood that under the above in part recited Letters Patent I
claim,―
Firstly. Grouping the tools used in machinery for cutting slate,
marble, and other like materials in hinged holders and presenting them
to their work, in the manner and for the purpose above described.
Secondly. Shaping the dividing or grooving tools and arranging them
in the order as and for the purpose above described.
In witness whereof, I, the said Henry Edward Curtis, have here-
unto set my hand and seal, this Twenty-fifth day of October, in
the year of our Lord One thousand eight hundred and seventy.
T T ANDIS