Printing Plates in Printing Machines.
Year: 1885

page_text: Printing Plates in Printing Machines.
We CHARLES EDWIN LAYTON and EDWIN JAMES LAYTON of the firm of
C. & E. Layton of 56 Farringdon Street, in the City of London, Printers do
hereby declare the nature of the said invention for "IMPROVEMENTS IN THE
METHOD OF AND APPARATUS FOR FIXING PRINTING PLATES IN PRINTING MACHINES
to be as follows:-
"
Our invention has for object the construction and application to lithographic
presses and printing machines of apparatus for stretching and fixing thin metal or
other printing plates in order that they may be printed from.
In carrying out our invention we provide a portable table or bed plate of
convenient depth for the printing plate to rest upon. The front edge of the table
or bed plate is sloped downwards from the surface and to this sloped portion is
fitted a gripper which gripper is conveniently constructed of a plate of metal with
screws working through it. Into this gripper the edge of the printing plate is
inserted and secured by means of screws. The inclination of the slope of the
bed and the beads of the screws are so arranged as to be clear from the action
of the printing cylinder and rollers. On the back edge of the bed we provide a
gripper of similar construction to that on the front edge but the sloped portion
instead of forming a part of the bed is separated from it and travels in slots cut in
the bed. This travelling gripper has shafts passing through the slots attached to
which are screws underneath the bed by which means the gripper is kept in an
upright position when pressure is applied. Screws pass through the travelling
gripper and abut against the end of the bed and by their action the gripper is
forced away from the bed. When a printing plate is fixed in the grippers at both
ends this action causes the plate to be stretched tightly over the bed as required
for printing from. Lugs projecting beyond the grippers and of the required height
are provided at each end of the bed to form abutments for the ordinary setting
screws in the beds of lithographic machines.
It will be obvious that our gripping and stretching apparatus is also applicable
to the cylinders of printing machines and to other than portable bed plates.
G. F. REDFERN,
4, South Street, Finsbury, London,
Agent for the Applicants.

page_text: Printing Plates in Printing Machines.
We CHARLES EDWIN LAYTON and EDWIN JAMES LAYTON, of the firm of
C. & E. Layton, of 56 Farringdon Street in the city of London, Printers, 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:-
Our invention has for object the construction and application to lithographic
presses and printing machines, of apparatus for stretching and fixing thin metal or
other printing plates in order that they may be printed from.
In carrying out our invention we usually provide a portable table or bed plate
of convenient depth for the printing plate to rest upon.
The front edge of the table or bed plate is sloped downwards from the surface,
.and to this sloped portion is fitted a gripper, which gripper is conveniently
constructed of a plate of metal with screws working through it. Into this gripper
the edge (bent to a suitable angle) of the printing plate is inserted and secured
by means of the said screws. The inclination of the slope of the bed and the
heads of the screws are so arranged as to be clear from the action of the printing
cylinder and rollers.
At the back edge of the bed we provide a gripper of similar construction to that
on the front .edge but the sloped portion instead of forming a part of the bed is
separated from it, and travels on a Hange on the bed for which purpose screw bolts
passing through alots in the flange are attached to the gripper, the screws being
operated from underneath the bed, by which means the gripper is kept in an
upright position when pressure is applied. Screws pass through the travelling
gripper, and abut against the end of the bed and by their action the gripper is
forced away from the bed.-When a printing plate is fixed in the grippers at both
ends this action causes the plate to be stretched tightly over the bed as required for
printing from. Lugs projecting beyond the grippers and of the required height are
provided at each end of the bed to form abutments for the ordinary setting screws
in the beds of lithographic machines.
In order to enable our invention to be fully understood we will proceed to
describe the same by reference to the accompanying drawing in which figure 1
represents a plan of an apparatus constructed according to our invention for fixing
printing plates in printing machines; figures 2, 3, 4, and 5, are vertical sections on
the lines A B, C D, E F, and G H, respectively of figure 1.-Similar letters in all
the figures represent similar parts.
a, is the table or bed plate of the apparatus, on the surface of which the printing
plate b, figure 2, rests when placed upon the apparatus; c, represents the slope at
the front edge of the table or bed plate a; d, is the plate of metal and e, e, are the
screws working through the same which plate and screws together form the gripper
which is fitted to the sloped portion c; f, is the plate and g, g, the screws of the
gripper plate at the back edge of the bed plate a, and which is of similar con-
struction to the gripper at the front edge; h, is the sloped portion of the back part
j

page_text: of, but separate from the bed a, which portion travels on a flange a¹, on the edge of
the bed as shewn; i, i, are the screw bolts attached to the travelling gripper I,
and j, j, are the slots in the flange a', through which slots the screw bolts, i, pass
and are operated from underneath the bed and serve to keep the travelling
gripper h, in an upright position when pressure is applied thereto; h, k, are the
screws passing through holes in the gripper f; the said screws h, work in the
sloped portion h, and abut against the edge of the bed a, as shewn, and by this
means the travelling gripper can be forced away from the bed; l, l, are the lugs
projecting beyond the grippers at each end of the bed a, and of the required height
so as to form abutments for the ordinary setting screws (not shewn in the
drawing) in the beds of lithographic machines; m, m, are springs placed in holes
or recesses in the sloped portions c, and h, of the bed a; these springs serve to
automatically raise the grippers d, and f, when relieved from the pressure of their
screws e, and g, so as to allow the edges of the printing plate to be easily released
therefrom or a plate to be inserted.
To make use of an apparatus of this construction the screws e, g, and k, are first
unscrewed or loosened and the sloping portion h, of the back of the bed a, is
placed close against the edge of the bed; the printing plate b, is then placed on the
surface of the bed and its edges bent to the corresponding angle are inserted
between the grippers d and f, respectively and the sloping portions c and h, as
shewn in figure 2; the set screws e and g, are then tightened so as to firmly grip
the edges of the plate b; the screws, are then operated so as to force the
travelling part , away from the edge of the bed a, whereby the plate b, will be
tightly stretched over the surface of the bed; to remove the plate b, it is only
necessary to turn the screws e and g, in the opposite direction and being loosened
the grippers will be forced open by their springs m, and the plate b, can be taken
off the bed a, and another one inserted.
It will be obvious that our gripping and stretching apparatus is also applicable
to the cylinders of printing machines and to other than portable bed plates.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
心
1. The herein described method of fixing printing plates in printing machines
by stretching them on a table or bed plate by means of gripping apparatus
substantially as herein before described.
2. The combination with a portable table or bed plate having sloped portions at
the front and back of gripping and stretching apparatus arranged and operating
substantially as and for the purposes hereinbefore described and represented in the
accompanying drawing.
3. The improved apparatus for fixing printing plates in printing machines
herein before described and represented in the accompanying drawing.
G. F. REDFERN,
4, South Street, Finsbury, London,
Agent for the Applicants.