AN IMPROVEMENT IN FORME CYLINDERS AND FORMES FOR WEB PRINTING
Year: 1885

page_text: We, JOSEPH FOSTER, FRANCIS FOSTER and JAMES YATES FOSTER all of the Bow
Lane Iron Works, Preston, in the county of Lancaster, Engineers do hereby declare
the nature of our invention for "AN IMPROVEMENT IN FORME CYLINDERS AND
FORMES FOR WEB PRINTING" and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement:-
This invention relates to the construction of forme cylinders for web printing,
and to the shaping of the types and of the rules or spaces between the lines of type,
and the securing of these on the cylinder so as to constitute a cylindrical forme,
our arrangement being particularly applicable in cases where the types and spaces
are large, such as are employed for printing placards, contents bills for newspapers,
and the like. For work of this class, the types are usually made of wood hollowed.
at the foot and rounded on the face to suit the circular section of the cylinder, the
periphery of which usually receives two turtles or type beds. We make the types
of a dovetail form in section and secure them in opposition to centrifugal force by
means of wedge shaped rules which are themselves held to the body of the cylinder
as we will explain referring to the accompanying drawings. Fig. 1 is a diagram-
matic transverse section of part of a forme cylinder with the types A secured on it
by means of the intervening rules B. The two sides of each type A are in the line
of tangents to a circle C somewhat larger in diameter than the circumferential
depth of the largest type, and consequently the type is of dovetail form deeper at
the base than on the face. If the depth of the type were exactly the same as the
diameter of the circle C, as illustrated by the type marked A', the two sides of the
type would in that case be parallel and the centrifugal force resulting from
the rapid rotation of the cylinder would tend to throw the type out. For larger
types, such as A2, a larger tangent circle such as C2 is employed. Fig. 2 is a
longitudinal section and Fig. 3 is an end view of the cylinder shewing how the
rules are fixed thereon. The two turtles or type beds T are secured to the cylinder
bosses by the bolts V. The rules B, which space between the lines of type, have
projecting ends entering slots bb whereby they are held against the periphery of
the turtle but are permitted to slide circumferentially to suit the matter in the
forme. When the forme is set up, it is secured end ways by the locking up plate E
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page_text: and side ways by the side sticks F which are pressed laterally by setting screws G.
Obviously types other than those made of wood may be shaped and secured in the
manner described.
"
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
Constructing the types and intervening rules employed on forme cylinders with
their sides tangential to a circle of diameter greater than the depth of the widest
type, substantially as and for the purposes herein set forth.
Dated this 7th day of February 1885,
ABEL & IMRAY,
Agents for the Applicants,
28, Southampton Buildings,
London, W.C: