Improvements in Machines for Sewing Boots and Shoes.
Year: 1894

page_text: Date of Application, 9th Nov., 1894-4ccepted, 13th Apr., 1895
COMPLETE SPECIFICATION.
Improvements in Machines for Sewing Boots and Shoes.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by the Deutsch-Amerikanische Maschinen-
Gesellschaft of 148 Mainzerlandstrasse, Frankfurt-on-the-Main in the Empire of
Germany) to be particularly described and ascertained in and by the following
statement :-
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This invention relates to improvements in machines for sewing boots and shoes.
and is especially applicable to machines employed for sewing the soles to the uppers
and this invention has for its object to impart either to the loop-former, or whirl,'
used for placing the thread in the needle, or to the shuttle or loop-catcher, which
causes the needle-thread to be looped with the second thread, such non-uniform or
intermittent rotary motion, as is best calculated to make each of these parts.
operate in a very efficient manner. The following means are preferably employed
for carrying out this invention, reference being made to Figs. 1 and 2 of the
accompanying drawings which illustrate at right angles to each other a portion of
a sewing machine constructed according to this invention.
On a shaft A' driven from the main shaft of the sewing machine by means of
suitable gearing is a disc A. carrying an eccentric or crank pin a. In order to
impart from the uniform rotary motion of the disc A a non-uniform or intermittent
rotary motion to the shaft B' which operates the shuttle driver or looping device
there is arranged on this shaft B' in front of the said disc A and parallel thereto
a cam-shaped grooved piece or "loop" B in the slot of which the eccentric pin a of
the disc A engages. The loop-former, loop-taker or shuttle-driver (as the case
may be) which may be mounted upon the shaft or spindle B' carrying the eccentric
loop B thus receives non-uniform or intermittent motion, owing to the eccentricity
of the shafts A', B' and the curved or cam-like shape of the loop B.
Figures 3 and 4 shew a modification of this invention employed when the distance
between the shafts A' B' exceeds the radius of the circle described by the crank
pin a.
In this case a connecting rod E is interposed as a link between the parts A
and B. This link or rod serves to transmit from the uniform rotary motion of the
crank disc A an intermittent or non-uniform rotary motion to the shaft B' through
the cam loop B with which the stud or roller a on the rod E engages.
The rod E
is arranged to slide in a guide D which is free to turn or oscillate about a fixed
pivot C to admit of the required oscillating movements of the said rod.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed declare that what I
claim is:
1. In boot and shoe sewing machines-a crank or eccentric pin on a shaft
operated from the main shaft of the machine the said crank pin working in a cam
grooved piece on the shaft which operates the shuttle driver or looping device
whereby the uniform rotary motion of the shaft carrying the crank pin is caused
to in part non-uniform or intermittent rotary motion to the shuttle or looping
device substantially as herein before described.
2. In boot and shoe sewing machines the eccentric or crank pin a on the disc A
mounted on the shaft A' in combination with the cam-shaped piece or loop Bon
the shaft B' for imparting non-uniform or intermittent rotary motion to the shuttle

page_text: or loop-taker or to the loop-former or whirl the shaft A' being eccentric to or out
of line with the shaft B' substantially as herein before described and illustrated in
the accompanying drawings.
3. The interposition between the shafts A' and B' of a connecting rod E adapted
to oscillate about a fixed pivot C but whose motion is not otherwise interfered with,
the said rod constituting a connecting link between the crank disc A and cam-
loop B for transmitting motion from the shaft A' to the shaft B₁ substantially as
herein before described and illustrated in the accompanying drawings.
Dated this 9th day of November 1894
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.