Improvements in Machines for Sewing Boots and Shoes.
Year: 1892

page_text: Date of Application, 30th Aug., 1892-Accepted, 1st Oct., 1892
COMPLETE SPECIFICATION.
Improvements in Machines for Sewing Boots and Shoes.
1, PAUL GÖHRING, of Oberursel, in the Province of Hesse-Nassau, Kingdom
of Prussia, Germany, Engineer, do hereby declare the nature of this invention and
n what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My invention relates to lock-stitch sewing machines for sewing boots and shoes
and more particularly to the kind having an oscillating awl piercing the sole from
below, and a hooked needle above the same, so that the sole may be sewed on its
whole circumference without removing the last; and my invention consists in
several novel devices the conjoint object of which is to secure a steadier and more
reliable working of the machine.
The general construction of the machine is the same as described in British
Patent No. 12,349 dated Sept. 29, 1886 and my present invention is an improve-
ment of the said patented machine.
My invention therefore consists first of suitable means for keeping the presser-
foot firmly and immovably pressed down on the sole, and releasing the latter only
during the time of advancing it by the length of a stitch.
My invention consists, secondly, of means for securing an automatic adjustment
of the presser-foot to the thickness of the sole.
My invention consists, thirdly, of a thread-guide, pivoted in a peculiar novel
manner so as to facilitate and steady its motion in comparison to that of the thread-
guides as constructed usually.
Fourthly and lastly, my invention consists of an improved mechanism for
imparting a very steady and regular motion to the shuttle.
My invention will be more readily understood by reference to the accompanying
drawings, in which :
Fig. 1 is a front elevation of my improved sewing-machine,
Fig. 2 is a side elevation of the same, partly in section,
Fig. 3 a plan view of the same, showing chiefly the means for imparting notion
to the thread-guide.
Fig. 4 a detail view of the presser-foot and its operating lever.
Similar letters denote similar parts throughout the several views.
a is the main shaft of the machine, and the shaft around which the awl-carrying
head e and the needle-carrying head d oscillate. On the shaft there is loosely
mounted the lever e, carrying at its front end the presser-foot el, and having a
spring, secured to its rear end, the other end of said spring being fixed to the
frame of the machine. 1 may of course substitute a weight for the spring f. The
rear end of the lever e is arc-shaped, as shown. Close to the lever e, and laterally
of the same, there is another lever g, likewise loosely mounted on shaft b, and
carrying a roller at its end, said roll working in a cam-shaped groove ³, pro-
This lever has
vided on a disky, which rotates together with the main shaft a.
g
a lateral extension h, which partly overlaps the arc-shaped end of the lever e.
The side of this extension facing the periphery of the said arc-shaped end is beveled
in the form of a gable roof, as shown at . In the free space left between these
beveled surfaces and the lever el locate a roll (or a ball) of such a diameter, that
it has a slight play at the place where the two beveled surfaces ¹ meet each other,
but is clamped between the parts e and when moving out of this position, as will
be readily understood by a glance at Fig: 2 of the drawings. I also secure to the
frame of the machine an adjustable set-screw j, the point of which lies in the path
in which the roll i moves together with the lever 9. A spring f' constantly tends
to raise the roll i.

page_text: The head carrying the awl c' (which is not shown in Fig. 2) and the head d
carrying the needle (shown only in Fig. 1) are loosely pivoted on the shaft and
oscillate to and fro, being impelled by the slotted cranks 2 and 2, and the levers
and d respectively, pivoted at o and having at one of their ends pins cd working
in the slots of the cranks e2 d2, and at the other end rolls c and d respectively
working in cam-shaped grooves, which are provided in disks rotated together with
the main-shaft.a.
I will now describe the thread-guide and the means for imparting an oscillating
motion to the same. The pivot of the lever k carrying the thread-guide, according
to my present invention, is located at ', between the shafts a and b, and as near aš
possible to the latter. A rocking motion of the lever and the thread-guide is
obtained by means of the roll secured at the end of the same, said roll working
in a cam-shaped groove, similarly to the rolls g, and ds. The thread-guide
proper is pivoted at to the lower end of the lever k in such a manner that it
may swing laterally. The remaining parts connected to the thread-guide are
constructed and operated as described in British Patent No. 12349, 1886.
The means for obtaining the lateral oscillation of the shuttle pare the following:
The cam-disc has a groove ', in which works a roll ¹, secured to one end of the
lever, pivoted at. The other end of the lever has the form of a toothed
sector, and engages with a similar toothed sector s forming one end of the double-
armed lever s, the other end of which is connected to the shuttle p.
the
u is a hook oscillating sideways and operated by means of the cam-disc :
function of this hook being the same as described in the above-mentioned
Patent 1234986.
The operation of my improved machine, in so far as it differs from the above
patented machine, is the following:
The set-screw is adjusted in such a manner that it will stop the movement of
the roll as the lever approaches its highest position, and thus force the said roll
between the lever e and the inclined surface 4, so that it will be clamped between
these parts and thereby effect a firm coupling between the levers e and g. In
consequence thereof, the presser-foot el secured to the former lever will be kept
strongly pressed upon the sole and hold the same tightly till the awl c¹ has passed
through it. When the boot or shoe has to be advanced by the length of a stitch,
the lever is depressed by the cam-disc, the roll i comes out of contact with the
set-screw, the levers e and gare momentarily uncoupled, and immediately here-
after the roll is raised by the spring f¹ so as to become clamped between the
levere and the upper inclined surface of the lever y. The levers e and y are
thus again coupled with one another. Consequently the lever e moves in unison
with the lever g while the latter continues being depressed by the cam-disk g³, and
the presser-foot el is lifted off the sole. The latter is thus free to be moved
laterally as required. When this lateral displacement has taken place, and before
the awl el is drawn out of the sole, the lever is again raised by the cam-disc g³,
and the levers e and y are coupled by the roll striking against the point of the
set-screw and being thereby clamped between the arc-shaped end of levere and
the lower inclined face of lever g, as already described.
It will be obvious that at each upward and each downward movement of the
lever the latter is momentarily uncoupled from the lever e. This state is
employed for automatically adjusting, the presser-foot e¹ to the exact thickness of
the sole. As soon as the lever e is uncoupled from the lever g the spring f asserts
its power to raise the rear end of levere and consequently to press the presser-
foot upon the sole. Thus an automatic adjustment of the presser-foot e¹ to the
thickness of the sole is secured. As the levers e and g are coupled immediately
hereafter, the position to which the presser-foot e¹ has been adjusted is preserved
invariable till the next adjustment takes place.
The operation of the thread-guide and its carrying lever will be easily
understood without further explanation. In consequence of the particular location
of the pivot A, between the shafts a and b, and as close as possible to the latter,

page_text: the length of the lever is reduced to a minimum, and it is possible to impart
motion to this lever simply by means of a cam-disc and a roll 2 working in a
groove 3 of the same. The machine, in consequence of this particular arrange-
ment, may be driven at any speed, whereas the speed was limited in the machines
of the same kind used hitherto, owing to the complication of the mechanism for
operating the thread-guide.
The mechanism for operating the shuttle p is also a considerable improvement
of that described in British Patent 12349, and avoids the unsteady movement and
rapid wear which occurred when employing the old mechanism. The movement of
the shuttle is smooth even in its extreme positions.
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 1
claim is :-
1. In a machine of the kind described, means for effecting a periodical coupling
and uncoupling of the presser-foot carrying-lever e and its operating-lever I for
the purpose described.
2. In a machine of the kind described, means for effecting a periodical coupling
and uncoupling of the presser-foot carrying-lever e and its operating-lever g, and
means for utilizing the momentary uncoupled state of said levers for an automatic
adjustment of the presser-foot e¹ to the thickness of the sole, for the purpose
described.
3. In a machine of the kind described: the combination, with the presser-foot e³,
the lever e carrying the same, said lever having an arc-shaped end, and the lever
adapted to be operated by a cam-disc ³, and having a lateral extension / provided
with inclines arranged in the form of a gable roof, of the roll i, the spring",
adapted to effect the automatic coupling of levers é and at each downward
movement of the latter, the set-screw j, adapted to couple the same parts auto-
matically at each upward movement of lever g, and the spring fadapted to effect
the automatic adjustment of the presser-foot e to the thickness of the sole,
substantially as and for the purpose described.
:
4. In a machine of the kind described the lever carrying the thread-guide k*,
said lever being pivoted at between the main shaft a and the shaft around
which oscillate the awl c¹ and the needle d¹, and nearer to the latter shaft, the
lever k being operated by means of a roll k² working in a cam-shaped groove k³,
substantially as and for the purpose described.
5. In a machine of the kind described the combination, with the shuttle p, and
the lever s, having a toothed sector ', of the lever r, having the toothed sector³,
and adapted to be operated by a cam-disc q, substantially as and for the purpose
described.
Dated this 20th day of Aus 1908
By F. G. Cassell,
Of Cassell & Co.,
PAUL GÖHRING,
22, Glasshouse Street, Regent Street, London, Agent for the Applicant.