IMPROVEMENTS IN CUTTING AND DRESSING MILLSTONES AND IN APPARATUS TO BE EMPLOYED FOR SUCH PURPOSE
Year: 1867

page_text: Sealed the 11th October 1867, and dated the 30th April 1867.
PROVISIONAL SPECIFICATION left by the said George Davies at the
Office of the Commissioners of Patents, with his Petition, on the 30th
April 1867.
I, GEORGE DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of
Middlesex, and No. 87, St. Vincent Street,. in the City of Glasgow, Civil
Engineer and Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN CUTTING AND DRESSING MILLSTONES AND IN APPARATUS
TO BE EMPLOYED FOR SUCH PURPOSE," (a communication to me from abroad by
Samuel Golay, of Paris,) to be as follows:-
Many trials have heretofore been made to substitute mechanical processes
for the difficult handwork of dressing millstones; notwithstanding pretended
success, however, millers are still compelled to employ hand labor for this
purpose, no machine having as yet really effected the desired object. The
great error committed has been that the hand tool or hammer, has been

page_text: retained and the required motion attempted to be imparted to it by mechanical
means.
The Inventor of the present improvements has succeeded completely in
discarding altogether this order of ideas and producing work entirely
mechanical, whilst the processes hitherto known have always retained in a
certain measure the employment of manual dexterity; so that according to
this system an inexperienced workman makes much better and more rapid
work than the most expert dresser working in the old manner. It is well
known that for several years the employment as a tool of hard stone, and
especially of the diamond, has been adopted in various trades. Different
applications have been made of these stones in working stones less hard, such
as granite and others, and it is by a new application of this principle that the
Inventor has arrived at the solution of the difficult problem of cutting and
dressing millstones.
The Invention comprises two essential points, firstly, the application of hard
stones, and especially of the diamond, to cutting and dressing the millstones,
this diamond acting so as to split off or chip the stone (exactly as the hand
hammer does) by attacking it with blows succeeding each other with a great
rapidity; the said blows may be produced by either a rotary or rectilinear
motion, but the tool or diamond carrier which has been found to work best in
practice acts by rotation, and in giving to this rotation a certain rapidity a true
chipping motion or succession of shocks is produced which attacks the stone,
and by causing it to chip or fly off in minute fragments produces the desired
work.
Secondly, an entirely new machine by the aid of which the diamond is
caused to work, and which will be understood from the following description: :-
The machine is constructed with a central socket supported by radiating arms
having set screws at or near their ends for levelling the apparatus; this socket
is placed on the end of the millstone axle so as to centre the machine by the
aid of set screws; if the running stone is to be dressed the centering is
effected by means of a pivot of wood which is fixed in the socket, and the end
of which enters the eye of the stone. On the framing is mounted a support
capable of turning on a bolt and of being fixed in any desired position by
means of another bolt which is movable in a curved or circular groove on the
framing; this support is furnished with a V-slide in which moves the tool'
carriage; this slide is usually in a horizontal position, but it can be inclined
when required, the holes through which the bolts pass that connect it to the
support being made slightly elongated for that purpose. The carriage can be
moved in the slide from the centre to the circumference and vice versa,

page_text: besides which it carries a slide which can move in a direction transverse to
that of the principal carriage; this second slide forms the tool carrier, and
supports the axle of the diamond tool on two points or pivots. The tool con-
sists of a disc armed on its circumference with a tooth of diamond or other
hard stone either in the rough or cut; it has a rapid rotary motion imparted
to it by means of an endless cord passing round a small grooved pulley keyed
on the axle of the tool and round a large grooved pulley keyed on the driving
shaft, which latter is vertical, and is supported on a column screwed to tho
top of the central socket; this column carries a bracket capable of being
raised and lowered and of turning on the column, and this bracket is provided
with a fixed axle on which a lever oscillates freely; the latter carries at one
end a pair of guide pulleys over which the endless cord passes, and at or near
the other end a counterbalance weight which has a constant tendency to raise
the pulleys, and thus keeps the endless cord always at a proper tension. The
diamond or other hard stone may be mounted in a variety of ways, but
the following arrangement appears to unite the best conditions of simplicity
and solidity-It consists of two discs or washers capable of being screwed
close together on an axle; in the interior faces of these discs and near their
circumference are formed small recesses of different sizes, which when the discs
are brought together form hollow cells having a small opening at the circum-
ference of the disc. A piece of diamond or hard stone is fitted into one of
these cells so that a point or angle projects through the opening in the cir-
cumference, and the two discs are then screwed tightly together so as to hold
the diamond perfectly firm.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Davies in the Great Seal Patent Office on the 30th
October 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of Middlesex,
and of No. 87, St. Vincent Street, in the City of Glasgow, Civil Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of April, in the year of our Lord One
thousand eight hundred and sixty-seven, in the thirtieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
George Davies, Her special licence, that I, the said George Davies, my exe-

page_text: cutors, administrators, and assigns, or such others as I, the said George Davies,
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 "IMPROVEMENTS IN CUTTING AND DRESSING MILLSTONES
AND IN APPARATUS TO BE EMPLOYED FOR SUCH PURPOSE," (a communication to me
from abroad by Samuel Golay, of Paris,) upon the condition (amongst others)
that I, the said George Davies, my executors or administrators, by an instru-
ment 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Davies, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement
in writing, and on reference to the accompanying Sheet of Drawings, that is
to say:-
Many trials have heretofore been made to substitute mechanical processes
for the difficult band work of dressing millstones. Notwithstanding pretended
success, however, millers are still compelled to employ band labor for this
purpose, no machine having as yet really effected the desired object. The great
error committed has been that the hand tool or hammer has been retained,
and the required motion attempted to be imparted to it by mechanical
means.
.
The Inventor of the present improvements has succeeded completely in
discarding altogether this order of ideas and producing work entirely
mechanical, whilst the processes hitherto known have always retained in a
certain measure the employment of manual dexterity, so that according to
this system an inexperienced workman makes much better and more rapid work
than the most expert dresser working in the old manner. It is well known
that for several years the employment as a tool of hard stone, and especially
of the diamond, has been adopted in various trades. Different applications
have been made of these stones in working stones less hard such as granite
and others, and it is by a new application of this principle that the Inventor
bas arrived at the solution of the difficult problem of cutting and dressing
millstones.
The Invention comprises two essential points, firstly, the application of hard

page_text: stones, and especially of the diamond, to cutting and dressing the millstones this
diamond acting so as to splitt off or chip the stone (exactly as the hand:
hammer does) by attacking it with blows succeeding each other with a great
rapidity; the said blows may be produced by either a rotary or rectilinear
motion, but the tool or diamond carrier which has been found to work best
in practise acts by rotation, and in giving to this rotation a certain rapidity a
true chipping motion or succession of shocks is produced which attacks the
stone, and by causing it to chip or fly off in minute fragments produces the
desired work.
Secondly, an entirely new machine by the aid of which the diamond is
caused to work, and which will be understood from the following description:-
The machine is constructed with a central socket supported by ra liating
arms, having set screws at or near their ends for levelling the apparatus ;
this socket is placed on the end of the millstone axle so as to centre the
machine by the aid of set screws; if the running stone is to be dressed the
centering is effected by means of a pivot of wood which is fixed in the socket,
and the end of which enters the eye of the stone. On the framing is mounted
a support capable of turning on a bolt and of being fixed in any desired position
by means of another bolt which is movable in a curved or circular groove on
the framing; this support is furnished with a y slide in which moves the
tool carriage; this slide is usually in a horizontal position, but it can be
inclined when required, the holes through which the bolts pass that connect it
to the support being made slightly elongated for that purpose. The carriage
can be moved in the slide from the centre to the circumference, and vice
versâ, besides which it carries a slide which can move in a direction transverse
to that of the principal carriage; this second slide forms the tool carrier'
and supports the axle of the diamond tool on two points or pivots. The tool
consists of a disc armed on its circumference with a tooth of diamond or other
hard stone either in the rough or cut. It has a rapid rotary motion imparted
to it by means of an endless cord passing round a small grooved pulley keyed
on the axle of the tool and round a large grooved pulley keyed on the driving
shaft, which latter is vertical and is supported on a column screwed to the
top of the central socket. This column carries a bracket capable of being
raised and lowered and of turning on the column, and this bracket is provided
with a fixed axle on which a lever oscillates freely. The latter carries at one
end a pair of guide pulleys over which the endless cord passes, and at or near
the other end a counterbalance weight which has a constant tendency
to raise the pulleys and thus keeps the endless cord always at a proper
tension.

page_text: Such being the nature and object of the said Invention for "Improvements
in Cutting and Dressing Millstones, and in Apparatus to be employed for such
Purpose," I will now proceed to describe more in detail the manner in which
the same is to be or may be performed or carried into practical effect; and in
order that the same may be distinctly understood I have annexed hereunto
a Sheet of Drawings illustrative thereof, and have marked the same with
figures and letters of reference corresponding with those in the following
explanation thereof, that is to say: - .
Figure 1 in the annexed Drawing is an elevation (shown partly in section)
of the improved apparatus drawn about one-third the actual size, and Figure 2
is a plan view of the same as seen from above.
A represents the millstone to be dressed, and upon which the machine is
mounted, the red lines indicating the radial grooves of the stone.
The machine comprises a frame B consisting of a central socket, from
which radiate the three arms b furnished with screws c, which serve for
levelling the apparatus; this socket is placed on the end of the millstone
axle C so as to centre the machine by means of set screws d when the fixed
or bed stone is to be dressed, but if the running stone is to be operated
upon then the centering is effected by means of a plug of wood which
is fixed in the socket and the end of which passes into the eye of the
stone. The levelling screws c do not bear directly upon the surface of
the millstone, but upon small plates e of cast iron which rest upon the
latter. On the framing is mounted a support D capable of turning on
a fixed bolt f, and of being secured in any desired position by means of
another bolt g which is capable of. being moved in the curved slot E in
the framing; to the support D a dovetailed slide F is connected by two
screws or bolts h, and it is upon this slide that the tool carriage G moves; the
slide F which generally maintains the horizontal position shown in Figure 1,
may, however, be slightly inclined when it is required to dress the central
hollow part of the stone where the corn enters; this is effected by slightly
elongating one of the holes through which the bolts h pass. The carriage G
can move on the slide F from the centre to the circumference, and vice versa,
and moreover it carries a slide H capable of moving in a direction transverse to
that of the principal carriage; this slide H carries below it the tool carrier I,
which is mounted upon points or pivots kc, and may be fixed in any required
position by means of the pressure screws j; in this tool carrier the axle J of
the tool K turns upon the points or ends of the screws i; the tool carrier is
also provided with two other pointed screws i¹, upon which the tool is mounted
when it is required to work near the centre. The tool K consists of a disc

page_text: (herein-after more particularly described) furnished on its circumference with
a tooth of diamond or other hard stone either in the rough or cut, and caused
to rotate rapidly by means of an endless cord or band l. In the top of the
socket B of the framing a small column L is screwed, the upper part of which
forms a kind of footstep in which the pointed end of a shaft M turns; the
latter receives its movement from any convenient shafting or motive power by
means of a cord or band passing round the pulley m; its other pulley n gives
motion to the cord or band 2 which causes the tool to rotate. The column L
carries a bracket or gallows N, which may be fixed at the desired height and:
position by means of a set screw; this bracket is furnished with a fixed stud o
on which a lever O freely oscillates; the latter carries at one of its extremities
the tension pulleys P, which guide the cord l, and at the other end a counter-
poise P,
which tends constantly to raise the pulleys P, consequently the latter
preserve the tension of the cord 7 during all the movements of the carriage G.
A to-and-fro motion is given by hand to the carriage G by means of the
bell-crank lever Q which turns on a fixed centre at q, the lower arm of this
lever being connected to the carriage by a link R. The lateral setting of
the slide II and consequently of the tool K is effected by means of a screw r
and a ratchet motion S. To counteract the ill effects of deflection which the
weight of the carriage might produce upon the slide Fa supplementary foot T
is fixed to that side of the latter opposite the carriage, this foot being curved
so as to allow of the free passage of the carriage from end to end of the
slide; the foot T is provided with a screw c¹ and a plate c¹.
The operation of the machine is as follows:-The apparatus being placed
upon the stone is levelled by means of the screws c and c¹, regulating the
height in such a manner that the diamond tooth of the tool will be at about
the height desired. The adjustment of the height of the latter is completed
by the screws j. The machine is centered by means of the set screws which
press against the millstone axle or the wooden plug which is placed in the
socket B. The machine is so placed that the slide F is parallel with the
groove to be dressed, the shaft M is then put in motion, giving movement
to the cord and consequently to the tool; then by the aid of the lever Q
movement is given to the carriage G, which thus moves along the slide F ;
during this movement the diamond tooth of the tool K which turns with
great rapidity attacks the surface of the millstone, and forms a radiating
furrow therein; the carriage is then drawn back by the ratchet movement S,
the slide His moved laterally, carrying the tool with it, and.a second furrow
commenced. This operation is repeated across the groove of the stone to the
end of the traverse of the slide II, after which for the following grooves of the

page_text: same division or group, the machine is slightly turned, and the parallelism
of the slide with the groove is effected by turning the support D round its
bolt f, which is then fixed in position by means of the bolt g; the carriage is
then set in motion again. The position of the machine must be changed
for each division or group of the furrows. As there are some millstones fur-
rowed to the right and some to the left the machine is so arranged that the
slide F may be fixed on either side of the lug of the. support D to which the
bolts h attach it..The position of the carriage and its movement may thus be
reversed for left-hand grooves. It will be observed that the pivotting of the
support D round its bolt f is not theoretically indispensible, but if this facility
were not afforded a much longer movement of the slide I would be required
to reach the three furrows of the division, and consequently there would be
a greater danger of its getting out of truth.
.
It may also be stated that the particular arrangement of the apparatus
which is shown in the Drawing is that which the Inventor considers the most
practical, but this arrangement may be varied without departing from the
principles of the Invention. The diamond also instead of acting by rotation,
might operate on the millstone by means of a rectilinear or a vibrating motion.
The diamond or other hard stone may be mounted in a great variety of ways.
The arrangement represented at Figures 3 and 4 is that which the Inventor
considers best to unite the conditions of simplicity and solidity; it consists of
two discs or washers capable of being screwed together on an axle between
the shoulder t on the latter and the screwed nut u. In the interior faces of
these discs and near to their circumference are formed small recesses v of
different sizes (see Figure 4); these recesses are opposite to each other in the
two discs, and when the latter are brought together form hollow cells having
a small opening at the circumference of the disc; a piece of diamond or hard
stone is fitted into one of these cells so that a point or angle projects through
the hole in the circumference, and the two discs are then screwed together by
means of the nut u so as to hold the diamond perfectly firm, and the tool is
completed.
Having now described the nature and object of the said Invention for
"Improvements in Cutting and Dressing Millstones, and in Apparatus to be
employed for such Purpose," together with the manner in which the same is
to be or may be performed or carried into practical effect, I would remark in
conclusion that I claim as the Invention communicated to me by the aforesaid
Samuel Golay,
Firstly, cutting and dressing millstones by means of bard stones (par-
ticularly the diamond) acting in the manner herein-before described.

page_text: And, secondly, the construction of the apparatus for working and moving
the tool for such purpose, as shown in the Drawings and above described, or
any mere imitation or modification thereof, operating in substantially the same
or a similar manner so as to produce the same results.
In witness whereof, I, the said George Davies, have hereunto set my
hand and seal, this Thirtieth day of October, in the year of our Lord
One thousand eight hundred and sixty-seven.
GEORGE DAVIES. (L.S.)