IMPROVEMENTS IN APPARATUS FOR DRESSING MILLSTONES.
Year: 1869

page_text: LETTERS PATENT to Richard Blezard, of Liverpool, in the County of
Lancaster, Millwright, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR DRESSING MILLSTONES.".
Sealed the 5th November 1869, and dated the 10th May 1869.
PROVISIONAL SPECIFICATION left by the said Richard Blezard at
the Office of the Commissioners of Patents, with his Petition, on
the 10th May 1869.
I, RICHARD BLEZARD, of Liverpool, in the County of Lancaster,
Millwright, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUS FOR DRESSING MILLSTONES," to be as follows:-
This Invention relates to that class of apparatus in which diamonds or
other hard stones or other hard mineral substances (hereafter, for brevity,
called diamonds) are employed, and consists of certain apparatus or
machines of novel construction, having motions of an entirely new and
distinctive character, that is to say, new motions as regards the
mechanism generally but not as regards the diamonds, the said apparatus
or machines being so constructed that the diamonds can be made to
operate by either a chipping, an abrading, or a ploughing action.

page_text: In devising and perfecting the said Invention it has been my main
object to provide self-acting apparatus capable of dressing the surface of
a millstone in straight or nearly straight lines radiating from the centre
thereof, or from a number of excentric points thereon, in less time than
by any of the apparatus now in use, and this whilst maintaining the
stone in true or proper face. By self-acting I mean apparatus which
when adjusted on a millstone and put in operation by the power
employed in the mill or by any other available power shall perform
automatically the whole operation of dressing the lands of the stone
without interference or attention.
The most distinguishing feature of the mechanism, by which the above
objects or advantages are secured, consists in giving to the radial arm
or arms whereon the tool carrier or tool carriers are made to slide to and
fro, either by itself or themselves, or with the supporting frame, an
intermittent motion over the surface of the millstone, around the centre
thereof, or around an excentric point thereon.
According to one modification I secure to the millstone spindle or a
stud a thimble fitted with a toothed wheel on its outer circumference.
Over the said thimble and toothed wheel I place the central hollow
boss of the supporting frame, the said supporting frame being formed on
its bearing surfaces into a true plane, so that at all times it levels the
machine on the stone and keeps the face true. From the said hollow
boss I lead outwards towards the skirt of the stone at any desired angle
one or more tool carrier arms, and by a connecting rod or rods from a
crank or excentric shaft supported on the top of the said hollow boss
give to-and-fro motion to the tool carriers. At the inner end of one of
the said arms, or of more than one, I support a horizontal shaft, fitted
with a ratchet wheel and pawl, and a worm or helix. At the end of
every inwards return stroke a tappet on the connecting rod or on the
tool carrier comes into contact with the ratchet wheel and causes it to
make a partial revolution. The worm or helix is thereby caused to turn,
and as it is geared with the stationary toothed wheel above mentioned
the frame and the arms, in fact the whole machine, with the exception
of the thimble and toothed wheel, are or is made to travel round on the
face of the millstone the distance for a new cut. When it is desired
to cause the diamond to attack the stone by a chipping motion I obtain
the required speed for the tool carrier by a train of wheels, and I employ
a cord and jack pullies of the ordinary kind to give motion to the tool

page_text: holder; when an abrading motion is desired I carry the driving cord
over horizontal shifting pulleys; and when a ploughing motion is desired
the tool is simply secured in the carrier.
According to another modification, in which substantially the same
parts are used, I dispense with the thimble and stationary toothed wheel,
and instead thereof place a ring with teeth around the periphery of the
stone and connect the ratchet wheel and worm, the latter to gear with
the teeth of the ring just described at the outer end of the tool carrier
arm or arms. In this disposition of parts the motion is equivalent to that
above described, that is to say, at the end of every outwards return
stroke the tappet, ratchet wheel, helix, or worm and toothed ring cause the
machine to traverse round the distance for a new cut.
Although I have described above the arrangement of parts and mode
of operation thereof which I prefer, it will be obvious various modifications
may be made, for instance, the tool carrier arms could be fitted on pins or
joints, so that they could be moved from time to time and be employed
to dress first one part and then another of the millstone, in lines parallel
to the master lines and furrows, exactly in the manner ordinarily followed
when dressing by hand. It will also be obvious that instead of providing
framework to bear on the millstone and level the machine the tool carrier
arms might be provided with feet to rest on the surface of the
millstone.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Richard Blezard in the Great Seal Patent Office
on the 10th November 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
BLEZARD, of Liverpool, in the County of Lancaster, Millwright, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of May, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Richard Blezard, Her special license that
I, the said Richard Blezard, my executors, administrators, and assigns,

page_text: or such others as I, the said Richard Blezard, 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 APPARATUS FOR
DRESSING MILLSTONES," upon the condition (amongst others) that I,
the said Richard Blezard, 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 Scal Patent Office within six
calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Richard Blezard, 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 in writing, reference being had to
the accompanying three Sheets of illustrative Drawings, and to the
figures and letters thereon, that is to say :-
"This Invention relates to that class of apparatus in which diamonds
or hard stones or other hard mineral substances (hereafter, for brevity,
called diamonds) are employed, and consists of certain apparatus or
machines of novel construction, having motions of an entirely new and
distinctive character, that is to say, new motions as regards the mechanism
generally but not as regards the diamonds, the said apparatus or
machines being so constructed that the diamonds can be made to operate
by either a chipping, an abrading, or a ploughing action.
In devising and perfecting the said Invention it has been my main
object to provide self-acting apparatus capable of dressing the surface of
a millstone in straight or nearly straight lines radiating from the centre
thereof, or from a number of excentric points thereon, in less time than
by any of the apparatus now in use, and this whilst maintaining the
stone in true or proper face. By self-acting I mean apparatus which
when adjusted on a millstone and put in operation by the power employed
in the mill or by any other available power shall perform automatically
the whole operation of dressing the lands of the stone without interference
or attention.

page_text: The most distinguishing feature of the mechanism by which the above
objects or advantages are secured consists in giving to the radial arm or
arms whereon the tool carrier or tool carriers are made to slide to and
fro, cither by itself or themselves, or with the supporting frame, an
intermittent motion over the surface of the millstone around the centre
thereof or around an excentric point or points thereon.
According to one modification I secure to the millstone spindle or a
stud or thimble fitted with a toothed wheel on its outer circumference.
Over the said thimble and toothed wheel I place the central hollow boss
of the supporting frame, the said supporting frame being formed on its
bearing surfaces into a true plane, so that at all times it levels the
machine on the stone and keeps the face true. From the said hollow
boss I lead outwards towards the skirt of the stone at any desired angle
one or more tool carrier arms, and by a connecting rod or rods from a
crank or excentric shaft supported on the top of the said hollow boss
give to-and-fro motion to the tool carriers. At the inner end of one of
the said arms, or of more than one, I support a horizontal shaft, fitted
with a ratchet wheel and pawl, and a worm or helix. At the end of
every inwards return stroke a tappet on the connecting rod or on the tool
carrier comes into contact with the ratchet wheel and causes it to make
a partial revolution. The worm or helix is thereby caused to turn, and
as it is geared with the stationary toothed wheel above mentioned the
frame and the arms, in fact the whole machine, with the exception of
the thimble and toothed wheel, are or is made to travel round on the face
of the millstone the distance for a new cut. When it is desired to cause
the diamond to attack the stone by a chipping motion I obtain the
required speed for the tool carrier by a train of wheels, and I employ a
cord and jack pullies of the ordinary kind to give motion to the tool-
holder; when an abrading motion is desired I carry the driving cord
over horizontal shifting pullies; and when a ploughing motion is desired
the tool is simply secured in the carrier.
According to another modification in which substantially the same
parts are used I dispense with the thimble and stationary toothed wheel,
and instead thereof place a ring with teeth around the periphery of the
stone and connect the ratchet wheel and worm, the latter to gear with
the teeth of the ring just described at the outer end of the tool carrier
arm or arms. In this disposition of parts the motion is equivalent to
that above described, that is to say, at the end of every outwards return.

page_text: stroke the tappet, ratchet wheel, helix, or worm and toothed ring cause
the machine to traverse round the distance for a new cut.
Although I have described above the arrangement of parts and mode
of operation thereof which I prefer, it will be obvious various modi
fications may be made; for instance, the tool carrier arms could be fitted
on pins or joints so that they could be moved from time to time and be
employed to dress first one part and then another of the millstone in
lines parallel to the master lines and furrows exactly in the manner
ordinarily followed when dressing by hand. It will also be obvious that
instead of providing framework to bear on the millstone and level the
machine the tool carrier arms might be provided with feet to rest on the
surface of the millstone.
In order that others may be enabled to make and use machines
constructed in accordance with my Invention, I will now proceed to
refer to the accompanying explanatory Drawings.
DESCRIPTIONS OF THE DRAWINGS ON SHEETS A. AND B.
Fig. 1 is a side elevation; Fig. 2, an end elevation; Fig. 3, a trans-
verse vertical section through the middle of the machine, and Fig. 4, a
plan, the mechanism for operating the rotating tool being removed; all
of a machine adapted to dress millstones in lines radiating from the
centre, or from a number of excentric points near the centre towards
the skirt by the action of revolving tools fitted with diamonds. The
dotted lines between A, A, on Fig. 4 indicate the direction and
relative position of the cracks which I prefer. These cracks are furthest
apart near the skirt, and this I consider advantageous. In all these
views like letters are marked on the same parts.
1, millstone; 2, runner stone spindle; 3, thimble and toothed wheel,
formed in one piece or so fitted together that the wheel cannot move
around the thimble. If the top of the spindle 2 is angular in section
the thimble 3 is formed to fit tightly over it, but if it is circular in
section, bolts or other means are employed to fasten the thimble thereto.
4, frame planed true on its bearing surface; 5, supporting central boss,
secured to 4 by bolts or otherwise; 6, 6¹, tool carrier slides, secured to
the frame 4 by bolts 7, 7', and capable of being adjusted to the selected
angle by the bolts .8, 81, passed through the slots in the cross pieces
of 4; 9, 91, tool carriers; these are caused to move to and fro on the
slides 6, 6', the required distance by the adjustable connecting

page_text: rods 10, 10, and crank 11, the latter formed with or connected to
the vertical stud 12, to which the necessary speed is imparted by the
train of wheels hercafter referred to; 13, 13', tool adjusters; these
consist of pieces fitted to slide vertically in grooves formed in the
tool carriers 9, 91, and fitted with screws to raise and lower them;
14, 14, operating tool, the clamping discs thereof with recesses for
the diamonds are fitted on a spindle which rests in bearings formed
in 13, 13; 14 tappet piece formed with or secured to the tool carrier 9;
this slides on the forked tappet slide bar 16, whereto the shiftable
collars 17 are fastened. The tappet slide bar 16 carries a pallet 18,
which gears with the ratchet wheel 19. The spindle of the said ratchet
wheel has secured to it the worm 19', and the said worm gears with tho
stationary toothed wheel 3.
To impart rapid rotary motion to the operating tools, and to operate the
tool carriers at the proper and necessarily much reduced speed, I employ
the mechanism now to be referred to :--20, vertical spindle resting on the
step pedestal 21. This pedestal is supported by the boss 5. 22, driving
pulley operated from any convenient power; 23, pulley for the endless
cords 24, 24. These cords are led over jack pullics 25, 25', fitted on the
spindles 26, 26', attached to the weighted levers 27, 27. The weighted
levers rest and are free to vibrate on studs secured to the rods 28, 28.
The cords are led downwards over the pullies on the operating tools.
The train of wheels to give motion to the tool carriers consists of
wheel 29, secured on spindle 20; wheel 30, secured on an intermediato
shaft 31; wheel 32, geared with wheel 33 and a pair of elliptical wheels 34,
35, to impart uniform motion to the tool carriers.
To dress a millstone by the machine above described and illustrated
on Sheets A. and B. of the Drawings it is simply necessary to place the
machine on the surface of the stone and, after adjusting the operating
tool to cut the proper depth, give motion to the driving pulley 22; this,
by the pullies 23, 23', causes the cords to run and give great speed of
rotation to the operating tool (such cords being kept in constant tension
by the jack pullies 25, 25¹), and at the same time by the train of wheels
the tool carriers are made to slide to and fro on their arms over the face
of the stone. At the end of every inwards stroke the tappet piece 14
comes into contact with one of the collars 17 on the tappet slide bar 16,
and causes the pallet to impart a partial revolution to the ratchet
wheel 19 and worm 19¹; thus at the end of every inwards stroke as
aforesaid moving the whole frame over the surface of the stone around

page_text: the spindle 3 the distance for a new cut or crack. At the end of every
outwards stroke it will be observed the tappet slide bar 16 is drawn back.
If the diamond is required to act by a ploughing or cleaving action the
parts above referred to by the numbers 1 to 19¹ inclusive are all that are
necessary, the crank being coupled direct to a spindle on which the
driving pulley is affixed, and such spindle rotated at the required speed.
Of course the tool would be held fast so as to leave the diamond con-
stantly in contact with the stone. And if the diamond is to act by
travelling over the surface of the stone whilst it has imparted to it a
motion of rotation on its own axis, then the running cords are passed
around the tool so as to impart rotary motion thereto. Guide pullies
would be required for this purpose, as will be obvious, but the other
parts of the machine would remain substantially as shewn.
DESCRIPTION OF THE DRAWINGS ON SHEET C.
Fig. 5 is a plan, and Fig. 6 a side elevation of a machine similar in
nearly all its parts to the machine delineated on Sheets A. and B. It is
shewn adjusted to dress a millstone in lines radiating from the centre to
the circumference. The distinguishing feature of this modification
consists in the employment of a toothed stationary ring encircling tho
millstone instead of a toothed wheel placed near the spindle. The same
parts are denoted by like letters in both Figures.
tool carriers;
a, millstone; b, framework; c, tool carrier slides;
e, connecting rods; f, crank; g, tool adjuster; h, operating tool;
i, tappet; j, tappet slide bar with collars / and pallet; 1, ratchet wheel;
m, worm; n, toothed ring supported by three brackets, provided with
set screws which when in use abut against or pass into the millstone;
the said ring is levelled by three or more suspenders which rest on the
stone until the set screens are tightened; o, driving pulley; p, pulley
for endless cords q; r, supports for balanced levers 8 of the jack
pulleys tu, wheels, spindles, and studs forming train for imparting
motion to the crank.
Fig. 7 is a plan, and Fig. 8 a side elevation of so much of a machine
constructed in accordance with my Invention, as is necessary to illustrate
the means I employ for dressing a millstone with cracks parallel to the
master lines and furrows of an ordinary millstone. In this modification
which is shewn arranged to dress by giving to the diamond a so-called
rectilinear motion, the machine, as a whole, has exactly the same inter-
mittent motion imparted to the frame or arms as in those herein-before

page_text: described, but in addition thereto means are shewn and described,
whereby the tool carrier slide is made to move parallel to the master
lines and furrows. The same letters denote like parts on both views.
1, millstone; 2, spindle; 3, thimble and stationary toothed wheel;
4, frame; 5, central boss; 6, driving spindle; 7, crank; 8, connecting
rod; 9, tool carrier slide, secured by the bolt 10 to the frame 4, and left
free to be moved at its inner end as hereafter appears; 11, tool adjuster
and slide, the tool in this arrangement is simply a diamond fitted to the
bottom of the slide; 12, tappet slide bar; 13, ratchet wheels; and 14,
worm to move the frame every throw of the crank; 15 slide, fitted to
move by an intermittent motion on the segmental portion of the frame 4,
the top of the said segmental slide is formed with teeth and a worm 16
gears therewith, such worm being operated by a ratchet wheel 17 and
tappet bar 18. The ratchet wheels 17 and 13 are operated in the
following manner:-When the tool carrier 9 nears the inner end of its
stroke it comes into contact with the bar 19 supported on a fixed stud,
and moves it inwards at one end towards the centre of the stone and
outwards at the other end, the former end carries the tappet slide bar 12
with it and thereby pushes the ratchet wheel 17 around on its axis, but
the latter end draws the ratchet wheel 13 around by having a pullet on
the under side of the forked pallet bar 21. The tappet slide bar 12 is
provided with a collar to releive the pallets. By the mechanism
described the whole machine is made to travel by an intermittent motion
over the surface of the stone, and the inner end of the tool carrier slide 9
is at the same time made to partake of an independant onwards motion,
whereby to keep such slide 9 parallel to the furrows. As the lands
between the master lines and furrows are of unequal length it is requisite
to provide means to throw the operating diamond out of action at the
proper time. Hence the adaptation of the mechanism which I now
proceed to describe:-A short shaft 22 passes through a bearing formed
in an opening in the tool carrier 9 into the tool slide 11, where it is fitted
with an excentric boss, the other end is fitted with a fixed arm 23; 24 is
a double threaded screw whereon jam nuts 25 are made to slide.
of these nuts moves on a feather formed on the tool carrier slide hence
it cannot rotate with the screw 24. During each movement of the tool
carrier 9 outwards and inwards the arm 23 comes into contact with the
nuts 25, and is deflected either to the right or left. This causes the
excentric boss to make a partial revolution and throw. the tool away
from or into contact with the stone. The position of the nuts 25
One

page_text: determines the time at which the tool is turned out of or into action,
hence it is important to move them at the proper time. For this purpose
I employ the movable studded arm 26 attached to the tool carrier 9.
Every outwards stroke this comes into contact with the screw threads 27,
and causes the screw 24 to make a partial revolution. In this way the nuts
are traversed in the one direction or the other according as the machine
is dressing from short to long lands or from long to short lands. After
the machine has dressed a full quarter and during the time the
tool is crossing the master line, I employ a handle at 28 and by the
worm 14 run the slide 15 backwards and with it the tool carrier
slide 9. I also throw the studded arm 26 out of gear and by turning
the screw run the nuts back. When these are run back I throw the
pallet of ratchet wheel 13 (if one be used), and also the studded arm 26
into gear. These movements are easily effected during the time the
machine is crossing the master line, hence the machine even in this
modification operates so as to dress the whole land of the stone without
stopping.
Having now described the nature of my said Invention and par-
ticularized the same by various modifications thereof, I would have it
understood that I do not confine myself to the exact details shewn as
various modifications may be made without departing from the leading
features of my Invention, for instance, instead of employing a frame
the bearing surface of which is so distributed that it bears on a con-
siderable portion of a millstone the tool carrier arms might be provided
with bearing feet, what I do claim is, apparatus combined, arranged, and
operating substantially in the manner and for the purpose herein
set forth.
In witness whereof, I, the said Richard Blezard, have hereunto
set my hand and scal, this Eighth day of November, in the
year of our Lord One thousand cight hundred and sixty-nine.
In the presence of
J. T. KING,
Patent Agent,
Liverpool.
RICHARD BLEZARD. (L.S.)