Improvements in Sewing Machines.
Year: 1896

page_text: Date of Application, 20th Feb., 1896-Accepted, 21st Mar., 1896
COMPLETE SPECIFICATION.
Improvements in Sewing Machines.
I ALEXANDER BUICK PETERS of 44 Tenter Street South, Goodman's Fieldś
in the County of London, Manufacturer, 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:-
This invention relates to that class of sewing machines which is known as
"Over-seamers," and the object of the invention is to improve the machine for
sewing sacks and bags and other goods which forms the subject of Letters Patent
granted to Morris Lachman, and dated the 25th January 1887, No. 1113.
In the Specification of said Patent, a curved looper is employed to bring the
loop of the needle thread from below round the edge of the work and into the line
of the descending needle above the work.
To ensure the loop being carried around above the work, a hook-shaped arm
suitably operated is employed to hold the loop on the point of the looper. The
strain on this arm is very great, and it is consequently liable to injury.
Now the chief object of the present improvements is to overcome this difficulty.
Another improvement has relation to the take-up, which, in the previous
machine, was not entirely satisfactory. There are also several minor alterations,
which, with the improvements before referred to, are the result of experiments
made during practical working of the machine
In the accompanying drawings,
Fig. 1 is a side elevation of a machine with the improvements adapted thereto,
the side of the bracket standard above the table being removed.
Fig. 2 is a front elevation, partly in section, the section being taken on or about
the line x, x, Fig. 1.
Fig. 3 shows my improved construction of "loop"-retaining finger on its slide.
and showing the operating mechanism in connection therewith.
Figs. 4 and 5 show the throat plate in top view and under side view.
Figs. 6, 7, 8, and 9 show, detached, in side view and front view, the looping
mechanism at work in four different positions.
A is the table of the machine, and A¹ the bracket standard. B is a horizontal
shaft, by which the various parts of the machine are driven. C is the needle
which is secured in any convenient manner to the vertically-reciprocating needle
bar C. This bar C¹ slides in guides C2 in the head A2, and is actuated by the
pendent rod D, which extends downwards through the table A, and is connected
with the crank E on the shaft B.
In practice, it is found that any vibration of the needle bar during its movement
is detrimental to the proper working of the machine, and therefore the guides C'
are made sufficiently long to give perfect support to the needle bar during the
whole of its travel.
F is the curved looper mounted on the end of the shaft F1, which axially
reciprocates under the influence of the toothed sector, in the manner fully described
in the Specification of the Patent before referred to.
This curved looper has to stand considerable strain, and to enable it the better
to do this, its shape has been slightly modified by increasing its stiffness at the
neck.
This change of form enables me to make a smaller hook, that is to say, reduce
the diameter of the circle, and by this means, combined with placing the parts of

page_text: the machine a little more closely together, enables me to reduce the throw of the
crank E on the shaft B, and thus reduce the travel of the needle considerably. In
this way, I may use a shorter needle than heretofore, which is also an element of
strength, and I have not so much thread to take up.
The take up which I find most satisfactory for my purpose consists of a bell-
crank lever G, actuated by a grooved cam H on the shaft B, with which engages
one arm of a rock lever I, the other arm being connected with the shorter arm of
the take-up lever. The longer arm of this take-up lever is curved at the outer
end in the usual way, and its action is rendered smooth and efficient by the operation
of the barrel cam H.
In place of the hook-shaped arm described in the above named Patent, which
holds the loop on the looper or hook, I use a retainer K, shown, detached, in side
view at Fig. 3, fitted to a slide L, which works on a dovetailed guide M. This
slide is operated by a rod L' attached thereto, and connected with the strap of an
eccentric N on the shaft B.
The retaining finger K is wedge-shaped at its root, and terminates in a forwardly
projecting point.
This retainer K works in a groove a in the underside of the throat or cloth
plate A³ and in front of the looper shaft, so that the curved looper will wrap the
loop of the needle thread over it.
The throat plate A³ is formed with a recess b, through which the curved looper
works, a recess c in which the feed dog works, and a third recess d, across which a
finger fextends, as seen in Fig. 4.
When the looper F is about to commence its stroke, the retainer K is forward,
presenting its greatest width to the loop, as seen at Figs. 6.
In Figs. 7, the hook has taken the loop, and is commencing to lay it over the
retainer. In Figs. 8, the retainer is beginning to withdraw from contact with the
loop, and in Figs. 9, the needle, having caught the loop presented to it by
the hook, the retainer is entirely withdrawn, leaving the loop on the finger f of the
throat plate. The feed then takes place, and the loop is drawn off, the finger f
and is tightened up by the take up, after which the looper returns to its first
position, ready to catch up the thread and make a new loop.
This form of retainer admits of being made of any desired strength, and, while it
ensures the loop being held on the hook, it automatically presents a gradually
reduced breadth of surface to the loop, so as to allow of the loop of thread being
carried up over the edge of the work.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improvements in over-seaming sewing machines herein shown and
described.
2. The arrangement of take-up mechanism for overseaming sewing machines, as
herein shown and described.
3. The retaining finger K for overseaming sewing machines, constructed and
operating as herein shown and described.
Dated this 19th day of February 1896.
NEWTON & SON,
Agents for the Applicant.