Improvements in Apparatus for Producing Grained Surfaces on Lithographic Printing Plates.
Year: 1889

page_text: Date of Application, 5th July, 1889-Accepted, 10th Aug., 1889
AME TEIE DI DUITIATION,
Improvements in Apparatus for Producing Grained Surfaces on
Lithographic Printing Plates.
I, JABEZ GORHAM HARRIS, of 31 Pearl Street Providence, in the State of Rhode
Island, United States of America, lithographer, do hereby declare the nature of my
invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
My invention consists in a plate holding bed provided with raised sides for holding
a quantity of sand and a number of balls, with means for imparting a reciprocating
movement to the said bed, whereby the sand and balls, with water if desired, will be
made to traverse back and forth over the surface of the plate, the balls operating as
rollers to press the sand against the surface to be grained, as hereinafter fully set
forth.
Fig. 1, is a view showing a vertical section of the reciprocating bed employed to
carry out my invention.
Fig. 2, is a plan view of the same.
Fig. 3, is an enlarged detail section showing the plate, the balls, the layer of sand,
and the water.
In the accompanying drawings, A represents the bed upon which the zinc
plate B, to be grained, is secured by means of tacks inserted at its edges, or other-
wise. The bed A is provided with the raised sides C, C, and also with the supporting
wheels D, D, which run upon the tracks E E, or the bed may be supported upon
slides without the intervention of wheels or rollers. The driving shaft F is held in
the bearing stands G, G, and is provided with the slotted crank disk H, from which
connection is made to the bed A by means of the pitman I. Upon the plate B is
placed a quantity of dry sand a, and also a number of balls b, which are preferably
made of glass, and about the size of an ordinary playing marble. The rotary
movement of the shaft F will cause a reciprocating movement of the bed A and
the attached plate B, which, at the proper rate of speed and length of stroke, will
impart a back and forth rolling movement to the balls b, with the agitated sand,
thus serving to press the grains of sand against the plate B, to produce the finely
grained surface required for the purpose of surface printing. And in order to
secure the best result I add a supply of water to the sand and balls as shown by
the dotted line c, in Fig. 3, and in this case the desired effect will be produced
with great rapidity and of fine quality. Instead of the zinc plate B which is
attached to the surface of the bed A, a lithographic-stone plate may be grained in
the same manner, the upper surface of the stone plate being arranged about level
with the surface of the bed A, in order that the sand and balls may operate upon
the stone to its extreme edge with uniformity, as in the case of the zinc plate B.
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:
1. A plate holding bed provided with raised sides and holding a quantity of sand
and a number of balls, with means for reciprocating the said bed to agitate the sand
and balls upon the plate, substantially as described.

page_text: 2. A plate holding bed provided with raised sides and holding a quantity of sand, a
number of balls, and a quantity of water, with means for reciprocating the said bed
to agitate the sand, balls, and water, upon the plate, substantially as described.
Dated this 25th day of June 1889
JABEZ GORHAM HARRIS.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.