In- PROVEMENTS IN THE PROCESSES OF CUTTING AND DRESSING MILLSTONES APPARATUS TO BE EMPLOYED FOR SUCH PURPOS
Year: 1868

page_text: LETTERS PATENT to William Walker, of East Cross Causeway, in the
City of Edinburgh, Practical Engineer, for the Invention of "In-
PROVEMENTS IN THE PROCESSES OF CUTTING AND DRESSING MILLSTONES, AND
Sealed the 10th November 1868, and dated the 14th May 1868.
PROVISIONAL SPECIFICATION left by the said William Walker at the
Office of the Commissioners of Patents, with his Petition, on the
14th May 1868.
I, WILLIAM WALKER, of East Cross Causeway, in the City of
Edinburgh, Practical Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE PROCESSES OF CUTTING AND DRESSING
MILLSTONES, AND IN APPARATUS TO BE EMPLOYED FOR SUCH PURPOSE," to be as
follows:-
At one time millstones were entirely cut and dressed by hand labor
by means of a small metal instrument called a mill pick, resembling a
quarryman's pick, with which the stone was struck. More recently
machinery has been more or less employed in certain portions of the

page_text: operations of cutting and dressing these stones, but such machinery has
been found to be defective in many respects, particularly and in so far
as the application of hard stones and especially of the diamond to
the said process of cutting or dressing is concerned, the processes and
machinery now in use are defective in respect that they only produce
their effects by slitting off or chipping the stones by attacking them
with blows produced by a rotary or rectilinear motion, and the effect
produced is necessarily less regular than that produced by the present
Invention. Also the machinery is defective because the slide is only
moved forward and backward by the hand and is not self-acting in
connection with the driving power, and further because the machine can
only dress an inconsiderable portion of the stones without requiring to
be lifted and thereafter placed in a different position on the stone, and
no machine yet invented combines in itself the motions required for the
cutting and dressing of both the upper and lower millstones, nor does
any machine now in use or invented provide for the cutting or dressing
of millstones in their roughest state or cutting or deepening the roads
thereof by means of pickers or cutters of steel or other hard metal.
The present Invention obviates all or most of these defects, and
consists as follows:-
1. The application of a traversing motion to the cutting of millstones
by means of diamonds or other hard stopes.
2. A machine for applying the said motion distinguished from all
previous machines intended by other motions for the cutting and dressing
millstones by reason of the following improvements:-1st, the working
of the slide containing the tool cutter backwards and forwards by the
machinery, ensuring more regular action than working it with the hand,
and accompanied by the self-adjustment of the slide at the end of each
motion for the following motion; 2nd, the cutting of the stone in both
the forward and backward motion of the slide; 3rd, the making of a
second centre for changing the operation of the instrument in the area
upon which the slide moves, enabling the machine to be worked over
the greater part of the stone without the trouble and delay of changing
the position of the machine; 4th, an arrangement of mechanism for
raising and lowering a stenting pulley to regulate; the tension of the
driving cord or belt; 5th, the use of a number of cutters or tools in the
same holder operating at the same time; 6th, the mode of adapting
the machine to cutting either the upper or lower millstones as may be

page_text: required; 7th, the application of the said machine by means of steel
pickers to deepening the roads in the millstones.
The machine is placed upon a circular disc or frame the size of the
swallow of the stone; where the grain goes in there is a projection on
the upper surface of this disc with a hole right through to allow the stone
spindle to pass. A part of the disc is cut so as to admit of the swallow
of the stone being dressed when required. The above is part of the
arrangement of the machine as for cutting and dressing the bed stone.
For the running stone there is 'a piece fitted into the socket after
mentioned, so as to turn round; the bottom of this piece is enlarged so
as to fill the eye of the stone. On the outside of the above projection
there is a socket fitted so as to revolve upon the projection upon
the top of the disc; upon the one side of this socket is fastened the
For the greater
compound slide carries the rubbing substance.
steadiness of this slide and to prevent it rising or falling there is a
bracket on the outer end of the slide, which bracket projects over
the outside of the stone, and is angled downwards and fastened by means
of a set screw to the side of the stone.
On the slide and near the socket
is a universal or ball joint having a set screw for keeping it in position,
by means of which joint the position of the slide can be altered so as to
enable it to work and produce lines at any angle required. The requisite
motion is imparted to the slide by means of a belt or cord passing round
a revolving shaft over a stenting pulley the axis of which is carried by
a bush capable of rising and falling in fixed guides. On the bush are
two incline or cam surfaces, against which bears a small roller which is
carried by a lever working on a pivot at a point intermediate of its
length; the lower end of the lever is attached by means of a connecting
rod to the tool carriage, so that when the tool carriage moves to and fro
the lever is turned on its axis, and the roller at its upper end working
with the incline or cam surface on the sliding bush of the stenting pulley
raises and lowers this pulley, the pulley being brought to its lowest
position at each end of the stroke of the tool carriage, and to its highest
position when the carriage is midway between these points. This belt
or cord gives motion to an eccentric of crank or cam (either movement
may be used) which gives a traversing motion to the tool holder and
causes it to move backwards and forwards upon the stone.
The compound slide is composed of two parts, one a slide working
backwards and forwards betwixt the centre and circumference of the

page_text: stone, which motion is produced by a rack and pinion fastened to the
arm a little nearer the circumference than the universal joint. This rack
and pinion are moved in their forward and reverse movement by two
cross and open belts passed over the revolving shaft and shifted on the
termination of each forward or reverse movement by two catches
attached to the slide and working a lever by means of a connecting rod,
which lever shifts the belts at the close of each movement. The other
portion of the slide has a motion in a direction across that above detailed,
and it is moved by means of a screw-and-star motion worked by means
of a catch attached to the travelling carriage. Any number of diamonds
or other rubbing substances may he employed, and they may be fastened
in various ways, but the most simple mode is by compressing the rubbing
substance or substances by means of a screw or screws betwixt two jaws,
similar to those of a hand vice, said jaws having on their surface corre-
sponding spaces which when the jaws are screwed together from cells
or cases for the diamond or diamonds or other substances employed.
The diamond holder is fastened by means of screws to the second part of
the compound slide and it can be unscrewed and fastened to either side so
as to admit of the machine being used to cut at any angle required, and
either right or left hand, either for the upper or lower millstone. The
machine can be used for cutting or deepening the roads on the millstones
by means of a series of steel cutters fastened into a box by means of screws,
which box may either be attached to an extra arm placed and fastened
as is the other arm above described, or it may be fastened to the com-
pound slide at the places and in the manner mentioned in regard to the
diamond holder, and in either event it is worked by an eccentric moving
vertically upon two slides, the motion being produced in the same way
and by the same appliance as in the case of the diamond cutter.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Walker in the Great Seal Patent Office on 3
the 14th November 1868.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of May, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Walker, Her special licence that
I, the said William Walker, my executors, administrators, and assigns,
or such others as I, the said William Walker, my executors, adminis-
trators, 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 THE PROCESSES
OF CUTTING AND DRESSING MILLSTONES, AND IN APPARATUS TO BE EMPLOYED FOR SUCH
PURPOSE," upon the condition (amongst others) that I, the said William
Walker, my executors 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Walker, 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 thereof, that is to say:-
This Invention has for its object improvements in the processes of
cutting and dressing millstones, and in apparatus to be employed for
such purpose.
In the Drawings hereunto annexed is shown a machine constructed
according to my Invention, the cutter, which is of diamond or hard
stone, being held in a holder to which a rapid up-and-down and to-and-
fro traversing motion is imparted by means of an eccentric or crank, or
it might be a cam, at the same time that the carriage or slide which
carries the tool holder is caused to traverse in lines over the face of the
stone.
Any suitable arrangement of mechanism may be employed for causing
diamond or hard stone cutters, so carried and actuated to be moved to
and fro in lines over the face of the stone, and for giving a revolving.
motion to the eccentric, or crank, or cam, which gives the to and fro

page_text: traversing motion to the holder which carries the diamond or Hard Stone
cutter.
The arrangement of machine which I prefer to employ is shown in
the Drawing hereunto annexed.
Figures 1 and 2 show elevations of the machine, and Figure 3 shows
a plan view of the same; in these Figures a is the cutting point of
diamond or other hard stone held or nipped between two parts of the
holder b which are drawn together by a screw as is more clearly shown in
the full size views of the tool holder shown at Figures 4. The upper end
of the holder b is jointed to a link c which turns on a centre at c¹; dis
an eccentric working in a hole formed in the tool holder; this eccentric
is on an axis d, to which in the arrangement shown in the Drawing,
a revolving motion is imparted by means of a small rotary engine e
worked by preference by compressed air or vacuum, but it might be by
steam; or in place of this the axis might be driven by a cord, or belt,
or otherwise. The axis d' passes through the centre of a hollow arm
or support f, which at one of its ends carries a plate f¹ to which are
fixed the guides for guiding the tool holder in its to-and-fro movement,
and at the other end of the arm f is formed the outer casing of the
rotary engine e. The arm f is carried by the lower end of a slide f
which can be raised or lowered in the horizontal slide or saddle g by
a screw f, so that the cutting apparatus may be set to the required
height above the stone, the horizontal slide or saddle g is capable of
moving to and fro, along the horizontal bar or arm h which at its end
is carried by another slide or saddle capable of moving to
another slide bar which is at right angles to the bar h. The slide
bar is fixed to the millstone horizontally above its face by means of
arms or feet and clamps as is clearly shown by the Drawing, there being
one foot at each end of the bar, and an arm attached to its centre, and
at the extreme end of this arm is a sliding dog and screw with hand
wheel attached to grip the periphery of the stone; each foot has also
adjustable grabs & fixed in mortice holes by means of set screws as
shown at Figure 3, the advantage of this method is the ease and
rapidity with which it can be fixed to or freed from the stone. The
slide bar or arm h is not rigidly fixed to the slide or saddle k, but is
connected to it by a joint as shown at Figure 1, so that if the face of
the stone be hollowed in the centre the arm h may be adjusted
The
accordingly and be fixed at the angle desired by the screws m, m.
and fro on

page_text: operation of dressing a millstone is as follows:-The machine having
been fixed to the millstone as shown in the Drawing, so that the
cutter may be made to act upon the segment or part of the stone it
is desired to dress, the rotary engine is caused to impart motion to
the cutter, and then the saddle or slide 9 is moved from end to end
of the bar h by turning the toothed wheel g¹ carried by the saddle g and
which gears with the rack fixed to the arm h, this movement is most
clearly seen in Figure 3, the slide is then moved back again along the
arm and the saddle is moved a distance along the slide bar / equal to
the distance apart that it is desired to form the lines on the face of the
stone and then the saddle g is again caused to traverse from end to end
of the arm h. The saddle k is caused to traverse along the guide bar
or slide which carries it by means of a lever handle n being caused to
raise a pawl which engages with the ratchet wheel o on the axis of the
screw p, this arrangement is clearly shown by the Drawing. When one
segment of a stone has thus been dressed, the apparatus is shifted and
again fixed to the stone to dress another segment.
Having thus described the nature of my Invention, and the manner
of performing the same, I would have it understood that what I claim
is, the arranging apparatus for cutting and dressing millstones with a
tool holder carrying a diamond or hard stone cutter and receiving
motion by means of an eccentric, or crank, or cam, and also the cutting
and dressing millstones by means of such apparatus, all substantially as
herein described.
In witness whereof, I, the said William Walker, have hercunto
set my hand and seal, this Fourteenth day of November, in
the year of our Lord One thousand eight hundred and sixty-
eight.
WILLIAM WALKER. (L.S.)