Improvements in Spring-backs of Books.
Year: 1888

page_text: 1888
Date of Application, 12th Nov.,
Complete Specification Left, 6th June, 1889-Accepted, 13th July, 1889
PROVISIONAL SPECIFICATION.
Improvements in Spring-backs of Books.
I, CARL FRIEDRICH SCHUBERT, of Zurich, Switzerland, Book-binder, do hereby
declare the nature of this invention to be as follows:-
My invention relates to spring-backs of books, and its object is to impart to the
said backs a higher and more permanent degree of resilience than is attainable by
materials in use therefor at present.
For this purpose I make the spring-backs with a core or inner layer consisting in
a piece of hide so prepared, without tanning, as to present the required degree
of resilience, and formed in an arc of a circle corresponding to the shape of the
back. The main operations in preparing the said cores consist in slackening the raw
hide in lime, unhairing the same, steeping it in an infusion of bird's dung, cutting
pieces of the required size from the hide, stretching these on cylindrical molds
and drying them.
Dated the Ninth day of November 1888
CARL PIEPER,
Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in Spring-backs of Books.
I, CARL FRIEDRICH SCHUBERT, of Zurich, Switzerland, Book-binder, 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 :
My invention relates to spring-backs of books, especially of account books and the
like, and its object is to impart to the said backs a higher and more permanent
degree of resilience than is attainable by materials in use for this purpose at present.
Heretofore the inner portion of spring-backs has ordinarily been made by gluing
together several layers of thin pasteboard. Spring-backs thus prepared are, however,
too stiff at the beginning, so that the books provided therewith can only be opened
with difficulty and not without straining them, while after some time of use the backs
become slack and then do not any more answer their purpose to keep the leaves of the
opened book flat. Metallic fittings combined with such backs either increase their
stiffness, or they soon become useless by rusting, or bending out of shape, or
breaking.
.
In view of obviating these defects, I make the spring-backs with a core or inner
layer consisting in a piece of hide so prepared, without tanning, as to present the
required degree of resilience and formed, previous to its application, in an arc of a
circle corresponding to the shape of the back, but preferably of somewhat smaller
radius than the back is to have when the book is closed.
One method of preparing the hide, which is partly analogous to the ordinary
method of treating hides for tanning, consists in slackening the raw hide in lime, in
unhairing and washing it, in beating or rolling the same so as to make its thickness
uniform, in steeping it in an infusion of bird's dung (preferably pigeon-dung) and
in cleansing it again. According to another method the haired portion of the hide
is removed by means of a skiving machine, and the inner portion is employed without
further preparation. Pieces of the required size are thereupon cut from the hide,
stretched in wet state on cylindrical molds and allowed to dry. Spring-back-cores
are thus obtained which possess that lasting and unvarying resiliency, which has ever
been a desideratum in book-binding. They are light in comparison to their power of
ונ...מ

page_text: returning to their original form when bent out of the same, they are cheap, and by
their employment the binding of books is facilatated.
In the annexed drawing fig. 1. shows in transverse section an account-book having
its back provided with the described core. Fig. 2 is a perspective view of the book
without spring-back and outer portion of cover. Fig. 3 is a like view of the new
core ready for application, and fig. 4 a like view of the finished book in open state,
showing how the resilient back operates to make the leaves lie flat. Figs. 5, 6 and
are sections representing the manner in which the core allows the spring-back to yield,
when the book is being opened, and causes the back to assume the original form of
the core when the book is entirely open.
In fig. 1, a is the core, a² its covering of leather, cloth or the like, and a³ the
lining. d figs. 1 and 2 are the leaves of the book stitched to the flexible strips e,
which are glued to the pieces of pasteboard 6 forming the inner layers of the two
covers. care the outer layers of the covers attached by the lining a³ and the
covering a to the spring-back and glued to the inner layers 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 spring-back for books having an inner layer or core consisting in a resilient
piece of untanned hide, formed in an arc of a circle, substantially as described.
2. An article of manufacture consisting in a resilient piece of untanned hide formed
in an arc of circle and adapted to be used as core for the spring-back.of a book
substantially as set forth.
Dated the Fourth day of Inn's
CARL PIEPER,
Agent for Applicant.