Improvements in the Manufacture of Metal Plates or Sheets employed in Producing Autographic Stencils.
Year: 1892

page_text: Date of Application, 30th May, 1892-Accepted, 23rd July, 1892
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Metal Plates or Sheets
employed in Producing Autographic Stencils.
I, DAVID GESTETNER of 70 Chiswell Street, in the City of London, Manu-
facturer, 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, reference being had to the accompanying drawings
and to the figures and letters marked thereon:-
The invention has for its object improvements in the manufacture of metal plates
or sheets employed in the production of autographic stencils used in producing copies
of writing and other delineations.
Heretofore such plates or sheets have been formed of steel cut with a fine file
like surface, in the ordinary manner of cutting files; such plates or sheets have
also, according to Patent No. 20605 of the year 1890, been made by the aid of
roller dies.
Now, according to my present invention, I produce metal sheets or plates with a
"hub constructed
finely ribbed surface by the employment of a rotary cutter or
as shown in the accompanying drawings, in which
Figure 1 is a side elevation of such a rotary cutter or "hub,"
Figure 2 is a face view of part of such cutter drawn to an enlarged scale, and
Figure 3 is an end view of Figure 2.
Such rotary cutter is formed of hardened steel and with minute circumferential
annular ridges a and recesses b closely adjacent to each other, which ridges and
recesses are transversely cut or notched, as shown at c, in a direction parallel with
the axis of the roller or "hub," or inclined thereto, so as to form a series of minute
cutting edges. The said rotary cutter can be made of length equal to the width of
the metal plate or sheet or only of a section thereof, and they can be used at right
angles to the sides of such metal plate or sheet, or inclined thereto.
In carrying my invention into effect I mount a sheet or plate preferably of
soft steel on the slowly travelling table of a milling or other like machine, and I
pass it underneath a rotary cutter or "hub" of the character above described, and
to which rotary motion of suitable speed is given; the cutter will cut in the steel
plate or sheet a series of very minute ridges and intermediate recesses close
together; then, by altering the position on the travelling table of the metal sheet
or plate thus treated, another like series of ridges and recesses are made at any
suitable angle across the first series, thereby forming all over the surface of the
sheet or plate very minute pyramids in close proximity with each other.
Instead however of producing the cross lines by cutting as above described, they
may be produced by the employment of a roller die extending entirely across the
metal sheet or plate and acting at a single passage across the same; or the roller
die may be comparatively narrow and may be caused to act upon the sheet or plate
sectionally.
The plate thus treated is then hardened in any convenient manner.
A sheet or plate of comparatively hard steel or of iron may be treated as above
described without being subsequently hardened.
The metal plate or sheet, when provided on its surface with a series of minute
ridges and recesses in one direction only, can in such condition be used for the
preparation of stencils, but a better result is obtained by providing its surface with
a double set of such ridges and recesses as above described.
Metal plates or sheets provided with a surface of the character above described
are used in the well known manner in the preparation of a stencil, namely, a sheet
of waxed tissue paper is laid over the plate or sheet, and a stylus, held in the hand

page_text: as a pen, is used to produce the required writing or delineation thereon,' which, in
consequence of being made on paper supported on a surface composed of minute
pyramids or ridges, is full of perforations, thereby forming a stencil through which
ink is forced to produce the required copies of writing or other delineation in the
usual manner.
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:
The manufacture of metal plates or sheets of the character referred to, for use
producing autographic stencils, by the aid of rotary cutters either alone or
-combination with rotary dies, substantially as herein shown and described.
Dated this 201th dow of Mo- 1905
D. GESTETNER,
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.