Improvements in Sole Cutting Knives for Boots and Shoes.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Sole Cutting Knives for Boots and Shoes.
I WILLIAM HENRY DORMAN, of The Green Hall, Stafford, Engineer, do
hereby declare the nature of this invention to be as follows:-
Sole cutting knives, for use in presses in the manufacture of boots and shoes,
have usually been made of a moderate depth, say of about 14 inches, and either
made parallel through or slightly larger at the back than at the cutting edge when
it has been desired that the cut soles shall clear through the knife: or they have
been made smaller at the back than at the cutting edge when it has not been
desired that the soles shall clear through the knife.
Of late much deeper knives have been used, say from 4 to 6 inches deep, and
these have been made in the same manner as the former ones but always so as to
clear through.
The knives which are made parallel through, as well as those made larger at
the back, do not cut the sole square on the edge but produce undercut soles, that
side of the leather against the cutting block being smaller than the other side,
owing to the outside bevel of the cutting edge of the knife stretching the leather,
which afterwards shrinks back again, and also, if the knife is thin, causing it to
spring inwards a little as it cuts through the leather.
In order to produce a knife which shall cut the soles square on the edge and at
the same time shall allow of the cut soles freely clearing through, I form the
cutting edge bevelled inside, so as to counteract the outside bevel, for a sufficient
depth to cut through one sole and above this I form the inside of the knife slightly
larger and so through to the back so, as to allow of the cut soles clearing through
the knife.
Dated this 25th day of September 1896
I, WILLIAM HENRY DORMAN, of The Green Hall, Stafford, Engineer; 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 :-
Sole cutting knives for use in presses in the manufacture of boots and shoes"
bave usually been made of a moderate depth, say of about 14 inches and either
made parallel through or slightly larger at the back than at the cutting edge
when it has been desired that the cut soles shall clear through the knife or they
have been made smaller at the back than at the cutting edge when it has not been
desired that the soles shall clear through the knife.

page_text: Of late much deeper knives have been used say from 4 to 6 inches deep and
these have been made in the same manner as the former ones but always so as to
clear through.
The knives which are made parallel through, as well as those made larger at
the back do not with some conditions of leather cut the soles square on the edge
but produce undercut soles, that side of the leather against the cutting block
being smaller than the other side, owing to the outside bevel of the cutting edge
of the knife stretching the leather, which afterwards shrinks back again, and
also, if the knife is then causing it to spring inwards a little as it cuts through the
leather.
In order to produce a knife which shall cut the soles square on the edge and at
the same time shall allow of the cut soles freely clearing through I form the
cutting edge bevelled inside so as to counteract the outside bevel for a depth
sufficient to cut through one sole only and above this I form the inside of the
knife slightly larger and so through to the back so as to allow of the cut soles
clearing through the knife.
My invention is illustrated by the accompanying drawings in which :-
Fig. 1. is a side elevation of my improved knife.
Fig. 2. is a plan of the same and
Fig. 3. is a cross section.
The letter a denotes the cutting edge of the knife, b the inside bevel and c the
outside bevel. Above the inside bevel the inside of the knife is enlarged at d
and this enlargement is maintained through the knife to the back e so as to allow
the cut soles to clear through.
It is important that the depth of the inside bevel from a to d should be as small
as possible, at any rate somewhat less than the thickness of one sole, so that one
sole only should be held fast in the knife while cutting, more especially because
the greater the height of the bevel the more liable the knife is to be sprung or
wedged open and to cut soles of unequal widths.
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:
Constructing sole cutting knives with a bevel projecting part inside in the
manner and for the purpose herein described.
Dated this 3rd day of November 1906
W. H. DORMAN.