A NEW AND USEFUL IMPROVEMENT IN LOCK-STITCH SEWING MACHINES
Year: 1862

page_text: COMPLETE SPECIFICATION filed by the said Rosewell Thompson at tho
Office of the Commissioners of Patents, with his Petition and Declara-
tion, on the 29th July 1862, pursuant to the 9th Section of the Patent
Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, BE IT
KNOWN that I, ROSEWELL THOMPSON, of Boston, in tho County of Suffolk,
and State of Massachusetts, of the United States of America, have invented
"A NEW AND USEFUL IMPROVEMENT IN LOCK-STITCH SEWING MACHINES," and I
do hereby declare the nature of the said Invention, and the manner in which
the same is to be performed, to be fully described in the following Specifi-
cation and represented in the accompanying Drawings, of which Fig. 1 is
a sido view; Fig. 2, a front view; Fig. 3 a bottom view; Fig. 4 an enlarged
section through the centre of the revolving hook; and Fig. 5 an end view of
the driving head of the shaft E, showing the position of the driving pins.
Like parts are indicated by the same letters in all the Drawings; Figs. 1, 2,
3, and 5 are intended to be half size; Fig. 4 is full sizo.
Tho nature of my Invention consists as follows:-1st, in making tho packing
box, in which the hook revolves of raw hide, cloth, felt, or other suitable non-
metallic substance susceptible of the requisite amount of friction without
the use of any lubricator, thereby effectually obviating all liability of over
soiling the thread.

page_text: 2d, in constructing the removable bobbin case with a start upon its
outer end, for the purpose of revolving said case with the hook, and also to
act as a "cast off" for the thread when the point of the hook has entered the
loop formed by the needle.
3d, in making the body of said start elastic, and so attaching it to the
bobbin case as to spring out a little from it, in order that said case when
placed in the hook may be prevented from working out by the friction of the
said elastic start; &
4th, in the use of a spring on one side of the hole in the hook, and a
screw passing from the outside of the hook against said spring, whereby
the tension of the bobbin thread can be regulated without removing the
bobbin or its case.
To enable others skilled in the art to make and use my Invention, I will
now describe its' construction and operation.
A is a cast-iron frame or table to the top of which is screwed tho neck B; C
and D are starts cast upon the bottom of A, and E-is the driving shaft passing
through, and turning in said starts; F is a pulley attached to one end of the
shaft E, the periphery of said pulley being grooved to receive the band from
a fly wheel driven by a treadle in the usual manner; G is a pitman, one end
of which is pivoted to F, and the opposite end provided with a ball, which
fills a socket in the short end of the arm H, which vibrates on the fulcrum
X; I is another pitman uniting the long end of the arm H, to the needle
bar J, as shown in Fig. 1; L is the pressure foot, and Y is the cam lever
by means of which it is raised; K is the needle; is the thread; U is
the spool, and W the tension apparatus in general use. To one end of the
shaft E is attached the driver M, which is constructed with four arms as
shown in Fig. 5, each of which arms is provided with a pin d, projecting as
represented by dotted lines in Fig. 1; N are curved strips of brass, or iron
attached to the bottom of the table A, by means of screws v, as shown in
Figs. 1, 2, and 3. The inner side of these strips, N, N, is provided with a
groove about one-eighth of an inch in width and depth, and into this
groove is fitted a piece of raw hide, felt, cloth, or other suitable non-metallic
substance i, (Fig. 1,) to answer as a packing, in which the V-shaped flange k,
(see Fig. 4,) on the outer edge of the hook O bears. The design of this
packing has been described above and constitutes a great improvement. Tho
holes in N, N, through which the screws v, v, pass, are slightly oblong, so that
as the packing wears the picces N, N, may be brought nearer together. The
hook is driven by means of the pins d, two of which at a time are in two of the

page_text: holes c, c, (Fig. 4,) in the back flat side of the hook, the latter being inclined
as shown in Fig. 1, for this purpose, as also to give space for the needle to
pass down between the back of the hook, and the ends of the driving pins d;
P is the removable bobbin case provided with a central hollow axle 9, (sco
Fig. 4,) on which the bobbin f revolves; Q is the "cast off".the shapo and
position of which are clearly shown in Figs. 4 and 2, the lower end of which
is confined to the outside of the bobbin case by means of a rivet as represented
in Fig. 4. The body of the start or "cast off," Q is also elastic so as to confine
the case in the hole in the hook by pressing against it, it also by entering a
slot in the hook, as shown in the Drawings, causes the bobbin caso to rotate
with the hook. It moreover operates as a "cast off" for the thread when
the point of the book has entered the loop formed by the needle as repro-
sented in Fig. 1. Through one side of the bobbin case is a hole.c, (see Fig.
4,) through which the thread passes out from the bobbin, from which holo to
the open end of the case the case is made thinner so as to give space for tho
thread; opposite the hole e is a flat spring a, in a groove in the side of the hole
of the hook, one end of which spring is bent at right angles, and confined by
means of a pin as represented in Fig. 4; 6 is a screw passing through the
side of the hook so that its end shall bear against the spring a, the head of the
screw entering a hole below the surface of the hook as shown in Fig. 4, by
means of which screw it is obvious that more or less of tension can be
given to the bobbin thread, and without removing the bobbin or its case.
The feeding apparatus is similar to that of many machines in common use.
The feed plate T is raised at the proper time by means of the cam S, and
carried forward by means of the cam R striking against the start r, and it is
thrown back by means of the spring m; Z is an ear screwed to the bottom
of the table, and through this ear passes the screw n, provided with a set
nut o, and as the end of this screw strikes against the vibrating lever t, to the
one end of which an arm of the feed plato T is attached, it is obvious that the
length of the stitch can readily be regulated by said screw. The machine
is very simple in construction, durable, easily kept in working order, operates
noiselessly, and with the greatest speed and certainty.
Having thus described the construction and operation of my machine,
what I claim as my Invention, and desire to secure by Letters Patent, is,―
First, making the packing box i, in which the hook revolves, of raw hide,
cloth, felt, or other suitable non-metallic substance requiring no lubricator,
substantially as described for the purpose of obviating all liability of over
oiling the thread.

page_text: Second, the start Q upon, the bobbin case to cause the latter to revolve with
the hook, and also to operate as a "cast off" for the thread when the point
of the hook has entered the loop formed by the needle.
Third, making the body of the start Q elastic, substantially as and, for the
object specified.
Fourth, regulating the tension of the bobbin thread by means of the spring
a and screw b, substantially as described....
In witness whereof I have set my hand and seal at Boston this Fourteenthi