IMPROVEMENTS IN MACHINERY FOR GRINDING AND EQUALIZING THE THICKNESS OF LITHO- GRAPHIC STONES
Year: 1866

page_text: LETTERS PATENT to William Conisbee, of Herberts' Buildings, Waterloo
Road, in the County of Surrey, for the Invention of "IMPROVEMENTS
IN MACHINERY FOR GRINDING AND EQUALIZING THE THICKNESS OF LITHO-
GRAPHIC STONES."
Sealed the 28th August 1866, and dated the 1st March 1866.
PROVISIONAL SPECIFICATION left by the said William Conisbee at the
Office of the Commissioners of Patents, with his Petition, on the
1st March 1866.
I, WILLIAM CONISBEE, of Herberts' Buildings, Waterloo Road, in the
County of Surrey, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN MACHINERY FOR GRINDING AND EQUALIZING THE THICKNESS
OF LITHOGRAPHIC STONES," to be as follows:-
The present system of preparing stones for lithographic printing is very
defective, few stones being flat on either side, and none of them being of
equal thickness in all parts; this defect entails great loss of time in making
ready, and endangers the stone while in the press or machine, owing to the
system of underlaying, or, as it is called, "packing the stone," this being
the only means used at present of remedying the unevenness or inequality
of the thickness.
For the purpose of overcoming this defect, and thereby preparing stones
not only flat on either side but also of equal thickness in every part, I have
invented a machine of the following construction, viz.:-I construct two
vertical side frames of suitable length and height and connect them so as
to form a box or trough capable of holding water, on the top edge I

page_text: nount or fix bearings capable of receiving the axles of two circular iron
plates or discs, which I turn quite flat in a lathe; these discs rotate within
the trough, but in such a manner that while one rotates it is capable of
advancing or receding from the other, which works between shoulders.
Each disc is drilled with holes and countersunk on the inner or faced
side; they are also grooved in a suitable manner so as to hold the grind-
ing material. The traversing disc is provided with a lever for the purpose
of drawing it laterally in the bearings, while rotating also with a heavy
balance weight suspended by chains and hanging inside, the trough for a
purpose hereafter described. Between the faces of the discs, and extend-
ing the length of the frame or trough, I fix a planed rail or tramway,
supporting a wheel and carriage fitted with bolts and clips for the purpose
of holding the stone while it is ground or thicknessed. For the purpose
of driving or giving motion to the discs and the carriage and stone, I place
under the bottom of the trough a driving shaft fitted with fast and loose
pullies, also a pinion which is geared into a spur wheel fitted with a crank
stud or pin, the said wheel working on a stud fixed to the side of the
trough. For the purpose of giving a traversing motion to the stone I fit
a rocking shaft mounted in bearings fixed on the top of the side frames at
the extreme end; this shaft is provided with two arms and connecting
rods, one of the latter being connected to the stone carriage and the other
to the spur or stud wheel; the one connected to the stone carriage is
provided with gab ends to enable it to be lifted off the studs to enable the
stone to be withdrawn from between the discs for examination or final
removal after being ground. In order to give a rotary motion to the discs
I fix on the outer ends of the driving shaft two eccentrics, two levers,
and pawls, thus working each disc by means of a spur wheel fixed on each
shaft of the disc, at their outer end, this motion being for the purpose of
changing the relative positions of the grinding faces while the stone is
passed backwards and forwards between them in the process of grinding.
I also use instead of the eccentrics a worm fitted on the driving shaft;
the worms gear or work, in worm wheels, giving motion to shaft, and pinion
gearing into wheels fitted on the shaft of the discs, the object of either
movement being to give a slow rotary motion to the discs, so as to subject
the stone to a traversing or reciprocating action rather than a rotary one.
Having fixed the discs accurately so that all parts of the turned faces are
equidistant while in motion, and having described the method of passing
the stone between them, I will now describe the method of grinding
lithographic stones.

page_text: . The stone to be ground is placed on the carriage on its edge, and the
carriage is then pushed between the two discs; the disc lever is discon-
nected, when the balance weight carries the sliding disc.towards the stone
and presses it against the opposite one, when it is secured to the carriage
by means of bolts. The carriage is then connected by means of the gab-
ended connecting rod to the arm on the rocking shaft fitted at the end of
machine; the water, and grinding material may be fed between the discs
or brushed through the drilled holes from the outside so long as may be
found necessary to reduce the stone to an equal thickness, flat and smooth
en both sides; and should it be necessary to grind one side only of the
stone after it has been once thicknessed, the grinding material may be
supplied to one disc only, using water only to the other disc.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Conisbee, in the Great Seal Patent Office on the
30th August 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CONISBEE, of Herberts' Buildings, Waterloo Road, in the County of Surrey,
send greeting.
. WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of March, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said William Conisbee, Her special licence that I, the said
William Conisbee, my executors, administrators, and assigns, or such others
as. I, the said William Conisbee, 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 MACHINERY FOR GRINDING AND EQUALIZING THE THICKNESS
OP LITHOGRAPHIC STONES," upon the condition (amongst others) that I, the
said William Conisbee, 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

page_text: 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 William Conisbee, 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 :-
The present system of preparing stones for lithographic printing is very
defective, few stones being flat on either side, and none of them being of
equal thickness in all parts, this defect entails great loss of time in making
ready, and endangering the stone while in the press or machine, owing to
the system of underlaying, or, as it is called, "packing the stone," this
being the only means used at present of remedying the unevenness or
inequality of the thickness. For the purpose of overcoming this defect
and thereby preparing stones not only flat on either side, but also of equal
thickness in every part, I have invented a machine of the following con-
struction, viz. :-I construct two vertical side frames of suitable length
and height, and connect them so as to form a box or trough capable of
holding water. On the top edge I mount or fix bearings capable of
receiving the axles of two circular iron plates or discs which I turn quite
flat in a lathe, these discs rotate within the trough but in such a manner
that while one rótates it is capable of advancing or receding from the other
which works between shoulders; each disc is drilled with holes and
countersunk on the inner or faced side, they are also grooved in a suitable
manner so as to hold the grinding material. The traversing disc is pro-
vided with a lever for the purpose of drawing it laterally in the bearings
while rotating, also with a heavy balance weight suspended by chains and
hanging inside the trough for a purpose hereafter described. Between
the faces of the discs and extending the length of the frame or trough I
fix a planed rail or tramway supporting a wheeled carriage fitted with bolts
and clips for the purpose of holding the stone while it is ground or thick-
nessed. I place under the bottom of the trough a driving shaft fitted with
fast and loose pullies, also a pinion which is geared into a spur wheel fitted
with a crank, stud, or pin, the said wheel working on a stud fixed to the side
of the trough, and by a suitable train of gearing giving motion to the discs.
For the purpose of giving a traversing motion to the stone I fit a rocking
shaft mounted in bearings fixed on the top of the side frames at the extreme
end, this shaft is provided with two arms, and connecting rods, one of the
latter being connected to the stone carriage and the other to the spur or
stud wheel, the one connected to the stone carriage is provided with gab

page_text: ends to enable it to be lifted off the studs to enable the stone to be with-
drawn from between the discs for examination or final removal after being
ground. The stone to be ground is placed on the carriage on its edge,
and the carriage is then pushed between the two discs, the disc lever is
disconnected when the balance weight carries the sliding disc towards the
stone and presses it against the opposite one, when it is secured to the
carriage by means of bolts, the carriage is then connected by means of
the gab-ended connecting rod to the arm on the rocking shaft fitted at the
end of machine, the water and grinding material may be fed between the
discs or brushed through the drilled holes from the outside so long as may
be found necessary to reduce the stone to an equal thickness flat and
sinooth on both sides, and should it be necessary to grind one side only of
the stone after it has been once thicknessed, the grinding material may be
supplied to one disc only, using water only to the other disc.
And in order that my said Invention may be most fully understood, and
readily carried into effect, I will proceed to describe the Drawings here-
Figure 1 is a side view,
re 2 is an end view, and igure 3 a plan of
a machine constructed according to my Invention. a, a, are side frames
connected together so as to form a trough capable of holding water; a', a',
are bearings on these frames, they carry the axes b, b', on which the cast-
iron discs c, c¹, are mounted; these discs are made true on the face; they
are perforated as is shown and grooved as is indicated by the dotted lines.
The axis 6' is capable of sliding in its bearing so as to allow its disc c¹ to
approach to and recede from the other disc c; d is a weight which tends
constantly to draw the disc forwards, it is attached by chains to the
slide e, and this slide rests against a collar on the axis; fis a lever by
means of which the axis can be drawn back against the action of the
weight; g is a bar or rail running from end to end of the trough-like
frame, and h is a carriage with small friction rollers running thereon; i is
a connecting rod jointed at one end to the carriage, and at the other
engaging with a pin on an arm k¹ on the rocking shaft ; is another arm
on the same shaft connected by a rod with an eccentric pin m¹ on the
spur wheel m, which is mounted on a stud on the side of the trough-like
frame and is driven by a pinion on the main axis n; n', n', are fast and
loose pulleys on the main axis to receive a driving strap. From the spur
wheel m motion is. transmitted through the intermediate wheel o to the

page_text: wheel p' on the axis p, on this axis are also two small friction pinions q, q',
which are grooved to receive the v-form edges of the discs c and c¹, so
that the discs may be driven by these means. The axis P is carried in
bearings formed on the arms of the bell-crank levers r, r, which turn on
centres r,, on the frame and carry between their further ends a weight
s, which thus serves to press the friction pinions, q, q', firmly against the
edges of the discs c, c', the pinion q' is arranged to slide along a feather
on its axis p, so that it may adjust itself laterally to the position of the
disc c¹. From this arrangement it will be seen that as the main axis
revolves a to-and-fro movement is given to the carriage h between the discs
c, c', which at the same time are caused slowly to rotate. The stone to be
equalized and ground is placed on edge on the carriage h between the
discs c and c', the latter of which by its weight is caused to press firmly
against it. When thus placed the stone is firmly clamped in its place by the
clip bars, which is bound down upon it by the thumb nuts t, t, at its ends,
which work upon the screw bolts or stems u, u, fixed in the carriage; it is
secured also endways by a wooden block v, which is forced up by a binding
screw w so as to hold the stone firmly between the two end standards of
the carriage. The stone being thus adjusted in position, the machine is
set to work and sand and water are supplied to the discs, this is conve-
niently done by a brush applied to the exterior of the discs. The stone in
this way is quickly reduced to a true form, and as the work progresses the
stone can be run back for examination, the discs c, c', being for the moment
drawn out of contact with the stone by means of the hand lever f.
Having thus described the nature of my said Invention, and the manner
of performing the same, I would have it understood that I do not confine
myself to the exact details described, but what I claim is, the arranging
machinery for for grinding and equalizing the thickness of lithographic
stones in such manner that the stone is caused to traverse to and fro between
two slow rotating guiding discs which are kept truly parallel, the one to the
other, and are caused to bear on the surfaces of the stone as herein described.
In witness whereof, I, the said William Conisbe, have hereunto set
my hand and seal, this Twenty-ninth day of August, in the year of
our Lord One thousand eight hundred and sixty-six.
W. CONISBEE. (L.S.)