Improvements in the Method of Forming the Bottoms of Shoes.
Year: 1891

page_text: Date of Application, 25th Aug., 1891-Accepted, 21st Nov., 1891
COMPLETE SPECIFICATION.
Improvements in the Method of Forming the Bottoms of Shoes.
We, SAMUEL HENRY HOWLAND, Engineer, and ALFRED PARTRIDGE HANAN,
Manufacturer, both of 122 Centre Street in the City and County of New York, in
the State of New York, United States of America, 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:-
What we term the bottom-filling is the material introduced between the in-sole
and the outer sole, to fill up the hollow generally left after the shoe is in-seamed,
and which is required to be filled to give the proper surface on which to lay the
outer sole.
It has been common heretofore to make fillings of felt, leather or other material
in sheet form, and secure them by flour paste, which requires considerable skill and
labour in skiving, especially at the edges, to give a properly evened and slightly
rounded contour to the surface.
We have discovered that the work can be done more rapidly and perfectly by
applying a material in a plastic state and allowing it to harden in place. We can
use waste leather, utilizing the fine cuttings from edge trimming and heel trimming
machines, and if necessary grinding or otherwise evenly cutting or disintegrating
the chips to supply a sufficient quantity for our purpose.
The following is a description of what we consider the best means of carrying
out the invention.
We take the cuttings, raspings and finely divided leather in whatever condition,
which is produced in other departments of the shoe manufacture, taking care to
avoid as far as possible any admixture of thread or other foreign material, and to
avoid the presence of any considerable lumps, and incorporate therewith rubber
cement, by a process analogous to kneading, using a sufficient quantity of the
cement to make a mass sufficiently plastic to be easily spread and shaped. The
composition may be prepared before-hand by the aid of machinery, and kept in
tightly closed vessels ready to be removed by a trowel, spatula or other convenient
implement. The shoe when brought to a proper condition, presenting the usual
hollowed irregular surface after the welt has been secured, is held on a jack or
other convenient holder, and a sufficient quantity of our filling material in the
plastic state is applied in a central position and spread by the spatula or otherwise
over the whole of the hollowed surface which requires to be filled. Now the shoe
is left in this condition with the composition freely exposed to the air, and after the
filling hardens by the evaporation of the naphtha from the cement, leaving the
rubber holding the leather particles together, the shoe is ready to receive the outer
sole and be finished in the ordinary manner. The application of the composition
may, if preferred in any case, be made in excess and a portion subsequently
removed by abrading after it hardens.
Rubber cement is a well-known article of manufacture and trade. It is under-
stood to be manufactured from the cheaper qualities of African rubber, with
petroleum naphtha. Its constituents vary every moment by the evaporation of the
naphtha by exposure to the air. Under ordinary conditions, working rapidly in
the open air, we think about five pounds of finely cut leather will require ten
pounds of rubber cement; but the proportions should be varied so as to give a just
sufficient consistence to allow the spreading of the cement. The success of the
work is promoted by previously coating the surfaces thinly with rubber cement
alone before the composition is applied.
The accompanying drawings form a part of this Specification, and are transverse

page_text: sections of the bottom of the shoe in the reversed position in which it is held during
the manufacture.
Figure 1 shows the shoe lasted, with the lip turned up and the welt in place, and
the cavity in the bottom empty.
Fig. 2 shows the same with the cavity filled with the plastic composition.
Fig. 3 shows the same with the outer sole attached, and the bottom completed.
Similar letters of reference indicate corresponding parts in all the figures where
they appear.
A is the in-sole, and A¹ the turned-up lip thereon; B is the upper, sometimes
termed the vamp, and C the narrow strip termed the welt, secured around the
edges by the same stitches which bold the upper to the in-sole. D is the plastic
composition filling the cavity within the lip A¹; and G is the outer sole. A thin
coating of rubber cement d is applied to the interior of the cavity before the
plastic mass is applied. A similar coating is applied over the whole surface of
the plastic mass and of the adjacent parts before the outer sole G is applied.
Our experiments indicate that the soles filled with our composition are just
sufficiently flexible and elastic.
The material seems to be noiseless, but to reduce in the fullest degree the risk of
creaking it may be well to dust the entire surface of the filling with soap-stone
before applying the outer sole.
It will be observed that our filling is eminently light. The rubber remaining
after the evaporation of the naphtha does not fill the interstices between the finely
divided pieces of leather, but leaves a great number of minute air-spaces.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what
we claim is :
In the manufacture of shoes, the method described of forming the bottoms con-
sisting in turning up a rim extending around at a proper distance within the edge
of the bottom, sewing the welt in place outside of such rim, leaving a cavity within
the rim requiring to be filled, placing in such cavity a plastic mass composed of
leather and rubber cement intimately mixed in such proportions that the several
scraps are coated with the cement, spreading such mass to fill the space within the
rim, allowing it to harden in place with air spaces between the several scraps, and
subsequently securing the outer sole upon the bottom thus prepared, substantially
as herein specified.
Dated this 7th day of August 1891.
SAMUEL HENRY HOWLAND.
ALFRED PARTRIDGE HANAN.