IM- PROVED MACHINERY FOR DRESSING AND FURROWING MILLSTONES
Year: 1872

page_text: LETTERS PATENT to Thomas Mortlock, of Shafton Road, South
Hackney, in the County of Middlesex, for the Invention of " IM-
PROVED MACHINERY FOR DRESSING AND FURROWING MILLSTONES."
Sealed the 2nd July 1872, and dated the 4th January 1872.
PROVISIONAL SPECIFICATION left by the said Thomas Mortlock at
the Office of the Commissioners of Patents, with his Petition, on
the 4th January 1872.
I, THOMAS MORTLOCK, of Shafton Road, South Hackney, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVED MACHINERY FOR DRESSING AND FURROWING MILLSTONES," to be
as follows:-
:-
This Invention relates to novel and improved mechanical arrangements
for dressing and furrowing millstones, and consists,―
First. In adjusting and holding firm the cutter of machines, in which
a diamond cutter is employed by means of two screwed nuts placed onc

page_text: on the upper side and the other on the under side of the casting that
carries the cutter holder.
Secondly. In forming the screw employed to advance the cutter across
the stone hollow at one end, and placing such. hollow part upon a pin
fixed in one side of the framing of the machine, and also passing a 5
helical-tempered steel spring over the said pin so as to press against the
hollow end of the aforesaid screw to prevent backlash, and also com-
pensate for wear of the screw.
Thirdly. In fixing a compound speed wheel on the solid end of the
aforesaid screw. The aforesaid wheel being made with three sets of 1
teeth cast one behind the other, for example, the front of the wheel I
form with six teeth, behind this eight teeth, and behind these ten teeth,
so that according as one or other of these sets of teeth are brought into
contact with an adjustable pawl, hereafter described, in like manner the
screw on which this compound-toothed wheel is fixed will be advanced 1
through more or less space as desired.
Fourthly. In mounting the casting that carries the aforesaid screw
and cutter holder between long horizontal V shaped pieces of metal, and
in making the said pieces adjustable in the side framings of the machine
by means of a vertical screw at each end of the V shaped piece, and 2
employing transverse screwed bolts and nuts for fixing the said picccs
after they have been adjusted.
Fifthly. In hinging the pawl above referred to upon one end of a
square horizontal bar which passes through a square hole formed in a
casting adjusted to the top edge of that side of the framing of the
machine at which the before-mentioned compound wheel is situated, a
screw being employed to fix the aforesaid square bar and pawl so as to
come opposite to one or other of the sets of teeth in the compound
wheel, that when the said wheel comes into contact with the said pawl
as the cutter and screw holder is moved along its V shaped slides the
said compound wheel and screw on which it is fixed shall be moved
partly round, and advance the cutter a greater or less distance across the
surface on which it is intended to act.
Sixthly. In employing a rising and falling steel cutter as the cutting
instrument, the said cutter holder occupying the same position as the ;
diamond cutter before mentioned; but instead of fixing the cutter rigidly
in the framing that carries it, as is now the case where a diamond cutter

page_text: is used, I propose in using a steel cutter to operate therewith by per-
cussion, which may be effected by the following means:-Across the
casting that carries the movable cutter holder I place a bracket through
a hole, in the top of which the spindle of the cutter holder passes, and
to the top of this spindle I hinge by a pin one end of the horizontal lever
whose fulcrum is upon another pin fixed in an upright standard fixed to
or formed upon the aforesaid bracket. I also connect by other brackets
fixed to the casting that carries the cutter holder a horizontal grooved
roller extending across the width of tho machine, and mount the said
roller on axes capable of revolving in the last-mentioned brackets, the
centre of the aforesaid grooved roller being placed in a line with the
aforesaid lever, the outer end of the said lever taking into the grooves of
the grooved roller, so that as the said roller is rotated, which may be
effected by turning round a winch handle fixed on the axis thereof, the
outer end of the said lever will be depressed as each grooved part of the
roller passes over it, thereby raising the cutter, and by means of a helical
spring placed around the spindle of the cutter holder, and between the
under side of its respective bracket and an adjustable screwed nut placed
on the spindle, the elasticity of the said spring will be exerted on the
cutter, and cause it to strike the surface of the stone with sufficient
force to cut or dress the surface of the stone that is intended to be
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Mortlock in the Great Seal Patent Office
on the 4th July 1872.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of January, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Thomas Mortlock, Her special licence
that I, the said Thomas Mortlock, my executors, administrators, and
assigns, or such others as I, the said Thomas Mortlock, 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
DRESSING AND FURROWING MILLSTONES," upon the condition (amongst
others) that I, the said Thomas Mortlock, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of
their hands and scals, 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

page_text: Thirdly. In fixing a compound speed wheel on the solid end of the
aforesaid screw, the aforesaid wheel being made with three sets of teeth
cast one behind the other, for example, the front of the wheel I form
with six teeth, behind this eight teeth, and behind these ten teeth, so
that according as one or other of these sets of teeth are brought into
contact with an adjustable pawl, hereafter described, in like manner the
screw on which this compound toothed wheel is fixed will be advanced
through more or less space as desired.
Fourthly. In mounting the casting that carries the aforesaid screw
and cutter holder between long horizontal V shaped pieces of metal, and
in making the side pieces adjustable in the said framings of the machine
by means of a vertical screw at each end of the V shaped piece, and
employing transverso screwed bolts and nuts for fixing the said pieces
after they have been adjusted.
Fifthly. In hinging the pawl above referred to upon one end of a
square horizontal bar which passes through a square hole formed in a
casting adjusted to the top edge of that side of the framing of the
machine at which the before-mentioned compound wheel is situated, a
screw being employed to fix the aforesaid square bar and pawl so as to
come opposite to one or other of the sets of teeth in the compound wheel,
that when the said wheel comes into contact with the said pawl as the
cutter and screw holder is moved along its V shaped slides the said
compound wheel and screw on which it is fixed shall be movoved partly
round and advance the cutter a greater or less distance across the surface
on which it is intended to act.
Sixthly. In employing a rising and falling steel cutter as the cutting
instrument, the said cutter holder occupying the same position as
the diamond cutter before mentioned, but instead of fixing the
cutter rigidly in the framing that carries it, as is now the case where
a diamond cutter is used, I now propose in using a steel cutter
to operate therewith by percussion, which may be effected by the
following means:-Across the casting that carries the movable cutter
holder I place a bracket through a hole in the top of which the spindle
of the cutter holder passes, and to the top of this spindle I hinge by a
pin one end of a horizontal lever, whose fulcrum is upon another pin fixed
in an upright standard fixed to or formed upon the aforesaid bracket.
I also connect by other brackets fixed to the casting that carries the
cutter holder a horizontal grooved roller extending across the width of
'

page_text: the machine, and mount the said roller on axes capable of revolving in the
last-mentioned brackets, the centre of the aforesaid grooved roller being
placed in a line with the aforesaid lever, the outer end of the said lever
taking into the grooves of the grooved roller, so that as the said roller is
rotated, which may be effected by turning round a winch handle fixed 5
on the axis thereof, the outer end of the said lever will be depressed as
each grooved part of the roller passes over it, thereby raising the cutter,
and by means of a helical spring placed around the spindle of the cutter
holder, and between the under side of its respective bracket and an
adjustable screwed nut placed on the spindle, the elasticity of the said 1
spring will be exerted on the cutter, and cause it to strike the surface of
the stone with sufficient force to cut or dress the surface of the stone
that is intended to be operated upon.
Seventhly and lastly. In so shaping the upper rod or bar that ties or
connects the two side framings of the machine together at one end 1
thereof as to enable the cutter to pass freely over it. This I propose to
effect by cranking the said bar across the entire width of the machine so
as to make the said bar deeper in the middle than at the ends thereof.
And in order to explain my said Invention more clearly I will now
proceed to describe the construction of my improved machinery and its 2
mode of operation, reference being had to the illustrative Sheet of
Drawings accompanying these Presents, and to the numeral figures and
letters of reference marked thereon respectively as follows:―

page_text: A marks the framing of the machine, the part B whereof is made oval
for balancing the machine and keeping it firm on the stone; C are
adjustable pieces of metal made with V shaped edges for holding and
guiding the sliding casting D and parts connected thereto in proper
position; a arc screwed bolts and nuts for connecting and fixing the
pieces C to the framing; A and b are set screws near each end of the
under side of each of the pieces C for adjusting them vertically in proper
position. The sliding piece D contains the following parts :-c, c¹, arc
standards fixed to the piece D, and E is a movable bracket capable of
sliding across the piece D between the standards c, c¹; G is a screw
working on a pivot fixed to or formed at one end thereof, supported in a
hole in the slide D, and d is a pin fixed in the opposite side of the
slide D. The pin d is made smooth and cylindrical, and such part fits
into a hole of corresponding size formed in the end of the screw G. A
helical tempered steel spring e is passed over the pin d, and such said
spring is compressed between the side of the slide D and the end of the
screw G, thereby preventing backlash, as before stated; f, g, are notched
wheels fixed to the end of the screw; G and H is a pawl fixed on one
end of a pivot h (shewn more clearly at Figure 4); the other end of the
pivot has a handle or spanner fitted thereon for actuating the pawl H,
as presently described. The casting I to which the bracket E is fixed
has a screwed hole i (Figure 3) formed therein, through which the
screw G passes. The piece I has also a hole formed through it, through
which passes the rod K, which is connected by its upper end to the bent
lever k, whose fulcrum is a pin at l. The lower end of the rod K is
formed with a socket m to receive the steel cutters L or diamond
cutter M, shewn enlarged at Figures 5, 6, 7, the said cutters being
fixed in the socket m by a set screw n. I would here remark that in
using the diamond cutter a separate slide is used; the up-and-down
motion not being required the standards c, c¹, and bracket E, are
dispensed with. 1, 2, are screwed nuts fitting on to the screwed part of
the rod K, and 3 is a helical tempered steel spring held between the
nut 1 and under side of the bracket E. The nut 1 enables the spring 3
to be adjusted as required, and the nut 2 adjusts the extent of action of
the cutting tool L. N is a grooved or star-shaped roller shewn in cross
section at Figure 3; this roller is fixed on an axis o working in bearings
at the top of the standards c, c', and O is a handle fixed on o for impart-
ing motion to the roller N.

page_text: The operations of the above-mentioned machinery are as follows:-
The machine is placed upon the stone intended to be dressed, and
kept there by its own weight. Upon rotatory motion being imparted to
the roller N, the effect will be to lift the cutter and compress the
spring 3, the elastic force of which, after the points of the roller have
released the lever k, will cause the cutter to descend sharply and strike
the surface of the stone, and thereby dress or furrow the surface thereof.
The operator at each stroke of the cutter advances one or other of the
wheels f, g, the distance between one notch and the next, thereby turn-
ing the screw G partly round and moving the cutter holder D and cutter
crosswise of the surface of the stone, and so on after each descent of the
cutter until it has passed over the width of the stone. The operator
next proceeds by means of the handle P to move the cutter and slide D
longitudinally along the slides C to take a fresh cut, and so on in
succession until the entire surface of the stone has been dressed
or furrowed. The degree of fineness of the cut may be regulated by
bringing the pawl H opposite to one or other of the notched wheels f, g,
as before stated.
Having now fully described and set forth the nature and object of my
said Invention for "Improved Machinery for Dressing and Furrowing
Millstones," together with the means by which it may be effected,
I hereby declare my Invention to consist in, and I claim, the manner
above described and represented of constructing and operating with
machinery suitable for dressing and furrowing millstones, as con-
stituting improved machinery for those purposes.
In witness whereof, I, the said Thomas Mortlock, have hereunto set
my hand and seal, this Third day of July, in the year of our Lord
One thousand eight hundred and seventy-two.