Improvements in Apparatus for Damping Lithographic Stones.
Year: 1892

page_text: Date of Application, 2nd Aug., 1892
Complete Specification Left. 1st May, 1893-Accepted. 2nd June. 1893
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Damping Lithographic Stones.
I, GEORGE DUNCAN, of Clarendon Road Egremont, in the County of Chester,
Engineer do hereby declare the nature of this invention to be as follows:-
The object is to provide improved apparatus for evenly and efficiently damping
to the required degree lithographic stones.
Apparatus under my invention which is applicable to any lithographic machine
having a reciprocating stone consists essentially in the combination of one or more
rollers for distributing the moisture over the surface of the stone, a reciprocating
pad for giving moisture to the distributing roller or rollers, a damping roller for
imparting moisture to the reciprocating pad and a blanket or web for conveying
moisture from a tank to the damping roller. The tank is provided with one or
more cocks or taps for regulating the amount of water flowing on to the blanket
or web.
Further improvements consist in a diagonal roller for distributing the moisture
on the pad, a spring or springs for adjusting the pressure of the damping roller on
the pad, capillary guides for spreading the moisture over the blanket or web and
means for keeping the free end of the web stretched and resting on the damping
roller.
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Per pro J. T. KING,
J. Johnson,
Agent.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Damping Lithographic Stones.
1 GEORGE DUNCAN of Clarendon Road, Egremont, in the County of Chester
Engineer, 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 :-
The object is to provide improved apparatus for evenly and efficiently damping
to the required degree stones used in printing.
Apparatus under my invention which is applicable to any lithographic machine
having a reciprocating stone consists essentially in the combination of one or more
rollers for distributing the moisture over the surface of the stone; a reciprocating
pad for giving moisture to the distributing roller or rollers; a damping roller.
for imparting moisture to the reciprocating pad; and a blanket or web for con-
veying moisture from a tank to the damping roller. The tank is provided with
one or more cocks or taps for regulating the amount of water flowing on to the
blanket or web.
Further improvements consist (a) In employing a diagonally disposed roller for
distributing the moisture on the pad, or instead, in giving to and for longitudinal
motion to the said roller for distributing, and in placing it so as to rest on the
damping roller. (6) In the use of a spring or springs; weight or weights for
adjusting the pressure of the damping roller on the pad. (c) In providing capillary
guides such as threads or fine wires extending from the cock or tap nozzles over
the surface of the blanket or web for causing the moisture to spread well over the
surface of the said blanket or web. (d) In means for keeping the free end of
the blanket or web stretched and resting on or against the damping roller.

page_text: DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a longitudinal section, and Fig. 2 a plan of apparatus for damping
stones under my invention. a is part of the frame of the machine. are roller
for distributing moisture over the surface of the stone. The said rollers are free
to rotate in bearings c secured to the frame and are so disposed as to rest on the
stone to be damped as it passes to and fro beneath them. d is a pad which is
caused to reciprocate with the stone in the usual manner and passing beneath the
rollers imparts moisture thereto. e damping-roller carried in bearings in
standards secured to the frame a. The said damping roller e is free to move up
and down with its bearings in the standard, so as to rest on the reciprocating
pad d, as it passes to and fro beneath it. g, is a blanket or web secured at one
end to a bar fixed to the standards and carried at the other end by a bar i
coupled to levers j. The levers j are pivotted at to the standards and have
springs at their ends so as to cause the said levers to keep the bar and lower
end of the blanket or web g in contact with the roller e m is a tank carried in
arms n on the standards f, and free to rotate thereon, and provided with a series
of taps or cocks o from the nozzles of which water drops on to the blanket or
web by which it is carried to the damping roller e. p is a roller which rests on
the roller e and has to and fro motion imparted to it by means of a thread
the usual way.
The said roller serves to distribute the moisture on the roller e,
it also serves as a spring or weight to press the said roller against the pad d.
Instead of the above roller p a diagonal roller resting on the pad d as shown
by the dotted lines might be used for assisting distribution of the moisture on the
pad. In this case springs or weights would be used to cause the roller e to press
with sufficient force on the pad. is a lever for causing the tank m to turn op
its axis and raise the nozzles of the taps or cocks above the water level when it is
not desired to use the damping appliances. s, are set screws for forcing down the
rollers p and e if necessary. t, show wires or threads for conveying water from
the nozzles o over the surface of the blanket or web if desired-these may be used
or not as desired.
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in
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
First. In apparatus for damping lithographic stones, the combination of distri-
buting rollers reciprocating pad, damping roller, moisture conveying blanket or
web, and water tank substantially as set forth.
Second. The combination with damping apparatus claimed under the first claim
of any or all of the following devices, (a) a roller for ensuring the distribution of
moisture to the pad; (b) means for keeping the damping roller in contact with the
pad; (c) capillary guides from the cock or tap nozzles over the web or blanket,
and (d), means for stretching the web substantially as set forth.
Babed this 239th day of April 1893
April 1893
Per pro J. T. KING,
J. Johnson,
Agent.
10 ABD 1167 SIM nov
Per pro J. T. KING,
J. Johnson,
Agent.