IMPROVEMENTS IN THE MODE OF AND MEANS FOR SECURING SOLES UPON BOOTS AND SHOES, PART OF WHICH. IMPROVEMENTS ARE. APPLICABLE TO OTHER PURPOSES
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by Benjamin Davenport Godfrey
at the Office of the Commissioners of Patents, with his Petition,
on the 11th September 1868.
I, BENJAMIN DAVENPORT GODFREY, of Milford, Massachusetts, United
States of America, now of No. 8, Southampton Buildings, Chancery
Lane, in the County of Middlesex, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MODE OF AND MEANS FOR
SECURING SOLES UPON BOOTS AND SHOES, PART OF WHICH. IMPROVEMENTS ARE.
APPLICABLE TO OTHER PURPOSES," to be as follows:-
My Invention relates chiefly to a method of uniting the solės or
bottoms to the uppers of boots and shoes by the employment of screw
sprigs or nails of peculiar construction, whereby the work is performed
more cheaply and expeditiously than has hitherto been practicable, while
the strength and durability of the boot or shoe are greatly increased..
The common method of uniting the soles to boots and shoes by hand.
sewing, though producing a good quality of work, is so tedious and
renders the boots or shoes so costly that it has in a great measure given
place to other methods by which the work may be accomplished more

page_text: expeditiously and cheaply, though such work is inferior in strength and
durability to that produced by the first-named method.
The most convenient method of uniting a sole to a boot or shoe is by
nailing or pegging, which has been attempted in a great variety of ways,
the simplest way being to secure the sole with plain nails or sprigs. This
method however is objectionable for the reason that in a very short time
the nails work up through the leather and injure the foot and stocking.
Wooden pegs have been used as a substitute for the nails or sprigs, but
though this method of securing the soles has been partially successful
it is found that in warm dry weather the pegs shrink and allow the boot
or shoe to fall to pieces.
Another method of manufacture consists in using sprig-headed nails
driven through the soles and clinched upon a metal last. This method
however, though free to some extent from the disadvantges attendant
upon the others mentioned is yet imperfect. If the sprig should fail to
properly penetrate the insole or to be clinched thereon, or when the
head of the sprig is worn away, the sole or bottom will come off.
Another defect in this method of manufacture consists in the stiffness
or rigidity arising from the nails which must be driven into the sole
very closely together.
Another method, and the best hitherto employed, is. to. secure the sole
upon the boot or shoe by means of screws cut and screwed into the sole
by a machine especially designed for the purpose;, but this method; is
also objectionable because of its extreme slowness and consequent:
expense.
In practising my Invention I employ sgrigs which are formed with
screw threads, but which instead of being inserted by turning or
screwing them in are driven into the sole like an ordinary nail or peg,
two or more threads being formed on the sprig to give the screw a quick
pitch, so that the act of driving in the sprigs causes their rotation in
the leather. The threads of my improved screw sprigs are preferably
bevelled,, or inclined only on the front side, the back of the thread being
cut square down to the bottom, or nearly so. This álíape of the thread
allows the sprig to be very easily driven into the sole. The square
shoulders formed at, the, back of the screw, threads hold the sprig:securely
in the leather, but if the point is driven beyond; the surface of the sole
the spring may be clinched. My-improved sprigs do not require a head,
but I prefer to leave a small portion at the outer end plain or without

page_text: the screw thread. The said sprigs are tapered gradually from about the
centre to the point, so that they may drive more easily into the leather.
When properly inserted the plain or cylindrical portion at the end of the
sprig fills the perforation made by the screw and gives to the sole a neat
and finished appearance. My improved screw sprigs allow the work to
be quickly, conveniently, and cheaply accomplished, both on account of
the facility with which they are inserted and the small number required
to secure the sole, which is strongly and durably attached to the boot or
shoe without the rigidity or stiffness of ordinary pegged or nailed work.
The said sprigs, though chiefly designed for the purpose above set forth,
may be employed for other purposes.