IMPROVEMENTS IN AND ADAPTATION OF CYLINDER PRINTING MACHINES TO THE DOUBLE PURPOSE OF LETTER-PRESS AND LITHOGRAPHY, ALSO A NEW MODE OF DAMPING LITHO STONES, AND A NEW MODE OF REGISTERING AND POINTING IN SUCH MACHINES
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by Thomas William Nicholson at the
Office of the Commissioners of Patents, with his Petition, on the 22nd.
November 1865..
I, THOMAS WILLIAM NICHOLSON, of No. 3, Bell Yard, Gracechurch Street,
in the City of London, Lithographer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN AND ADAPTATION OF CYLINDER PRINTING
MACHINES TO THE DOUBLE PURPOSE OF LETTER-PRESS AND LITHOGRAPHY, ALSO A
NEW MODE OF DAMPING LITHO STONES, AND A NEW MODE OF REGISTERING AND
POINTING IN SUCH MACHINES," to be as follows:-
1. My Invention may be added or applied to any cylinder printing machine
that moves with a reciprocating horizontal motion, simply substituting litho
rollers for the usual composition rollers of the type machines. I reduce
the thickness of a litho stone to type high, and lock it in the bed in the usual
way of locking a "forme" in any ordinary letter-press cylinder printing machine;
where, by reason of the size of the stone this reduction of thickness would
make it too thin and fragile, the cylinder of the machine must be elevated,
together with the gear above the frame; this may be done at a very trifling
cost, and the machine would then admit of a lithographic stone of the ordinary
thickness being used. A little variation in thickness is already provided for
by the screw or pressure shaft of these machines. The stones may be backed
up as commonly practised by litho printers. It should be observed that
if the cylinder be elevated, a bed plate of equivalent thickness must be
placed on the type table when the machine is required to be used for
typography.

page_text: My new mode of damping litho stones is as as follows:-
2. For litho printing I construct a damper of any suitable material, such
as wood, galvanized iron, gutta percha, or any suitable material, forming a
semi-trough, that is, a beam or bar, stretching across the machine between
the first inking roller and cylinder. I pad the under side of this bar with
chamois leather and felt, or any suitable soft material capable of retaining
moisture. I adjust the bar by an arrangement of springs and screws to such
level that when the stone passes under it the damp is gently pressed or wiped
over the surface of the stone; a stud or wheel at each end projecting from
the under side keeps the damping bar clear of the inking table. I mount on
the side of the bar two inches from its base a slip to form a trough (surmounted
by a lid) of suitable depth, which I fill with water or a weak solution of
gum arabic, honey, or borax; this liquid is conveyed slowly, but constantly,
by a slip of woollen material reaching from the inside of the trough over the
lip down to the pad, thus providing the uniform supply of moisture to the
stone alternately with ink during the process of printing. The supply of
moisture is increased or decreased at pleasure by an adjustment of the lid
as also by the quantity of fluid in the damper trough. The inking or damping
apparatus, or either of them, can be thrown out of gear instantly by a cam
or lever.
3. My process of pointing or registering is as follows:-In the beam
supporting the feed table at the back of the cylinder I make tap'd per-
forations two or more inches apart, into which I place needle points
baving a worm or screw at the base. Over these points the front of the
feeding board is laid, which being perforated allows the points to appear
above its face, upon which the sheet is placed that is to be printed, and upon
being pressed down by the finger the sheet is perforated and fixed on the
points. As the printing proceeds the feeder rises to the grippers, which takes
hold of the sheet and releases it from its pinned position and passes it round
the cylinder for printing, and the work is complete. Upon the operation
being repeated for a second or more colors or for transverse sides or per-
fecting, the same perforation is used and a perfect register ensured.
What I claim is the damping process and method of pointing or registering
described in the above paragraphs numbered 2 and 3.