Stones and Plates.
Year: 1886

page_text: Stones and Plates.
I, CHARLES NIXON MORRIS, of 11 and 13 East Eighth Street, Cincinnati,
Hamilton County, State of Ohio, United States of America, printer, do hereby
declare the nature of this invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
Stones and plates used by printera in executing lithographic and analogous.
processes must have their impressing surface truly dressed and properly grained.
Such surfacing of the stones or plates must be effected when the stones or plates
are first gotten ready for use, and subsequently also when previously used stones or.
plates are to be prepared for a second or further use. It is highly important that
the surface of such stones or plates should be dressed to true planes comprehending
the entire facial surface of the stone or plate.
In executing my improvement I slowly reciprocate the stone or plate and cause.
grinding bars or plates to reciprocate upon the surface of the stone.at right angles
to the path of the reciprocation of the stone itself. The operation is conducted in.
a properly constructed machine, as hereinafter indicated, and, while the grinders
reciprocate upon the face of the stone, abrading material and water or other liquid
is applied to the stone. During the earlier period of the grinding operation the
full weight of the grinders rests upon the stone, but as the operation proceeds the
descending grinders come in contact with bearers which prevent further descent of
the grinders.
The grinding continues but the support furnished by the bearers prevents the
weight of the grinders being entirely imposed upon the stone, and the operation is
completed while the entire weight of the grinders is supported by the bearers.
The execution of the process, and the machine for the execution, will be readily
understood from the following detailed description taken in connection with the
accompanying drawing in which :-
Fig. 1 is a side view of a machine illustrating my invention.
Fig. 2 an end view of the same.

page_text: Fig. 4 an end view of a portion of the machine, this view serving to illustrate a
somewhat different form and arrangement of grinder from that illustrated in any
of the other views.
Fig. 5 a side elevation, with parts in section, of one of the grinders.
Fig. 6 a bottom view of the same.
Fig. 7 a vertical transverse section of one of the grinding shoes which are secured
below the grinders.
Fig. 8 an elevation of a portion of the inside face of one of the bearers.
Fig. 9 a vertical transverse section of the same.
Fig. 10 a vertical transverse section of the sand trough.
The larger portions of the machine bear strong resemblance to corresponding
parts of a metal planing machine. There is a large baso-piece er bed, constructed,
preferably, in massive box-form, and adapted to set upon a foundation and
maintain itself in perfect rigidity. This bed may have openings in its sides through
which the interior mechanism may be inspected etc., and the top of the bed is provided
with ways for the support and guidance of a reciprocating table. This table, A, is
to be reciprocated by any suitable mechanism, such, for instance, as is employed in
metal planing machines, and it should be similarly provided with means by which
the length of the stroke of the table may be readily altered to suit the length of
the stone to be surfaced. The table-driving mechanism found commendable in
practice involves a spur gear adapted to engage a rack upon the under side of the
table, a worm and worm wheel for revolving the spur gear, a pair of friction gears
for transmitting motion to the worm, a power shaft adapted to transmit motion from
the proper belts to the friction gears, a belt-shifting device to be operated by hand,
and a device for permitting the belts to be shifted automatically by the recipro-
cating table. The table is in the form of a rectangular pan adapted to confine the
slush and slop, resulting from the grinding operation, and deliver the saine into a
proper receiving tank which may be placed or formed within the bed of the
machine. Transverse ribs are cast upon the table and are dressed to true planes.
Wooden strips are laid longitudinally upon these ribs, and upon these strips the
stone or plate to be operated upon is laid. The surface of the table, between the
ribs, should slope downwardly from the centre so that the slop readily drains from
between the ribs. At the rear end of the table a rib, similar to the other ribs upon
the table, is somewhat isolated from the rest of the ribs. This is not intended to be
employed as a stone-supporting rib, but it is intended to be utilized as a carefully
preserved surface to serve as a gauge in adjusting the grinders, as hereinafter
pointed out.
The grinders consist of bars, C, (omitting for the present all reference to Fig. 4 of
the drawings) disposed across the machine over the stone. At each side of the
machine, bearers, D, are arranged to be vertically and simultaneously adjusted in
cheeks formed upon the sides of the bed, and should be arranged to be firmly
clamped in position by means of hand-nuts. A bifurcated lever mechanism, F,
serves for the coincident adjustment of the two bearers. The grinders, C, are com-
paratively narrow bars setting edgewise and guided in slots in the upper ends of
the bearers. The slots are provided each side with vertical rollers between which
the grinders move. These rollers are journalled in adjustable bearings secured to
the inside of the bearers, as will be understood from Figs. 3, 8 and 9.. At the
bottom of each slot an anti-friction roller is arranged in the bearer. The ends of
the grinders are thus supported by the bearers and adapted to reciprocate easily
between and on the rollers.
One of the bearers supports a vertical shaft, E, to which rapid oscillation is to be
given. In the illustration this oscillating motion is transmitted from the power
shaft which operates the table, such shaft being provided with an adjustable crank
at its end, from which crank a connecting rod connects to an arm upon the vertical
shaft. At the top of the vertical shaft is a double ended lever from which con-
necting rods reach to the centre of the grinders. By this means the two grinders
are rapidly reciprocated while the stone passes beneath them. In the drawing the

page_text: machine is shown as provided with two grinders, but, if desired, I may provide
four or six slots in the top of each bearer and use four or six grinders, motion being
given to all the grinders by independent connecting rods attached at various points
to the lever at the top of the vertical shaft. It will be understood that by this
arrangement of four or more grinders the grinders driven from the extremities of
the lever will have a greater length of reciprocation than those driven from the
inner points of the levers and that while the grinders driven by one end of the
lever move in one direction, those driven by the other end of the lever move in
the other direction. This dissimilarity of length and direction of motion has a
tendency to improve the grade of work produced by reason of the avoidance of
coincident scratching by the abrading material. The connecting rods which reach
from the arm to the grinders are elastically attached to the grinders so as to avoid
serious shock in the transmissions of the reciprocations. This elastic arrangement
will be understood from Fig. 5 in which it will be seen that the journal of the
connecting rod, instead of engaging directly into the bearer, engages in a block
seated in the mortise in the top of the bearer, rubber blocks or other springs being
placed in the mortise at each end of the block. A mortised cap-plate retains the
bearing block and springs in place.
I have thus far referred to the grinders as consisting of two or more bars set
edgewise and adapted for simple reciprocation. In Fig. 4 I illustrate a modification
in which I employ a single flat grinder which is reciprocated by means of cranks
upon the upper ends of vertical shafts at each side of the machine, the cranks being
adjustable to alter the stroke of the grinder. It will be apparent that a grinder
thus driven, instead of partaking of simple reciprocations will have every portion
of its surface partake of circular motions.
The grinders do not act directly upon the stone but are armed at their lower
edges or faces with removable grinding shoes as will be understood from Figs. 5,
6 and 7. These shoes are secured to the grinders by side clamps or analogous
devices, and they are formed of the various metals, phosphor-bronze being an
admirable material, or a solidified abrading material, as, for instance, corrundum.
I prefer to groove the working faces of these shoes, the grooves being disposed.
diagonally as shown in Fig. 6, and I prefer that the grooves be inclined in opposite
directions in the two shoes, whereby the abrading material will be more properly
distributed. I also prefer to make the corners of the shoes bevelled or rounded so
that they will not catch upon the edge of the stone as it seeks to enter under them.
The motion of the table must be so adjusted that the stone travels entirely out
from under the grinders at each stroke.
I also prefer to make the shoes double-faced, as indicated in the section at Fig. 7,
whereby either face of the shoe may be employed.
The two bearers are to be so adjusted, with reference to each other, that they
will support the grinders in a plane parallel to the gauging rib upon the table. It
follows that the grinders will dress the upper surface of the stones or plates parallel
with the surface which is supported by the table.
In the operation of the machine the stone or plate is placed upon the table as
before described.
The table is run under the grinders and stopped; the lever mechanism is then
adjusted until the bearers will support the grinders when the latter just touch the
surface of the stone or plate; and the bearers are then lowered a distance corre-
sponding to the amount which it is judged requires to be removed from the surfaco
of the stone or plate. The machine is then started, the stone reciprocating under
the rapidly reciprocating grinders, abrading material, as, for instance, sand, and
liquid, as, for instance, water, being supplied to the surface of the stone as the
grinding proceeds. It is obvious that the entire weight of the grinders is imposed
upon the stone, and that the grinding operation takes place under the pressure due
to the weight of the grinders. It is evident, however, that as the surface of the
stone is lowered by the grinding operation the grinders descend until intercepted
by the bearers, after. which time the grinding will proceed under light and

page_text: ultimately no pressure whatever, the grinders being entirely supported by the
bearers. The length of the stroke of the grinders, and the quality and the grade of
the abrading material employed are to be adapted to the nature of the effects to be
wrought.
The abrading material and liquid may be applied by hand, but I have provided
means for the automatic application and distribution of them. From each bearer
there projects upwards a standard, as seen in Fig. 1 and 2, but omitted in the
other Figs. These standards support a rod across the machine and from this rod is
suspended a sand trough disposed between the grinders. This sand trough is scen
in cross-section upon an enlarged scale in Fig. 10. The sand trough has a sieve
bottom adapted to permit the sand or other abrading material to sift through, and
the trough should have numerous transverse partitions to prevent the sand sifting
endwise in the trough. The trough is suspended from its rod by hangers, one of
which projects downward so as to be struck by pins which may be arranged in the
edge of the table of the machine. This arrangement causes the trough to be
agitated and the material to be sifted out upon the stone. Sand is to be placed in
as many of the sub-divisions of the trough as the width of the stone or plate being
operated upon would require. The sand trough, instead of being disposed between
the grinders may be carried in front of or behind all of the grinders, and be sup-
ported in suitable arms projecting upward and outward from the bearers. These
arms may also support a device for distributing water to the stone. In practice
I have employed, for the water distribution, a square tube provided with perfora-
tions in its lower corner for the outflow of the water, and a coun ction at its upper
corner to receive a hose to be connected with a source of water supply. Each end
of the tube is provided with a movable piston and these pistons may be adjusted to
confine the spraying operation of the tube to such portion of its length as the
width of the stone or plate being operated upon would require. Rods attached to
the pistons and serving in adjusting them may be rested in notches in supporting
standards in the same manner as the rod which supports the sand trough.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The mode of surfacing lithographic and other stones or plates, that is to say
by reciprocating the stone or plate under transversely reciprocating grinders
arranged to have their descent intercepted by bearers.
2. In a machine for surfacing lithographic. and other stones or plates the combi-
nation of a grinder arranged to operate under the pressure due to its weight, and a
pair of bearers provided with bearing surfaces in the form of true planes and
arranged to intercept the descent of the grinder and relieve the surfacing operation
of the pressure due to the weight of the grinder.
Dated this 23rd day of February 1886.