Improvements in Sewing Machines.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Sewing Machines.
I, SAMUEL BEACH COCHRANE of Ivanhoe Lodge, 2 Ivanhoe Road, Denmark
Park, London, S.E., Mechanician do hereby declare the nature of this invention to
be as follows:-
My improvements refer to the "Take-up" and the "Tension" devices, and also
to a means for using a small chain-stitch looper in connexion with a larger lock-
stitch hook. All of the above mentioned devices are applicable to various styles
of sewing machines, but especially to that class of such machines as have inter-
changeable looping arrangements for producing different kinds or varieties of
stitches.
The first part of this invention is an addition to, or modification of my invention
specified in Patent 10792-1891 and described on pages 4 and 5, of the printed
Specification commencing at line 55 on page 4 and continued to the 6th line
(inclusive) on page 5, and shown also on sheet 1 Figures 2 and 10.
I now propose to make the plunger or piston in two parts, one fitting into the
other. I also propose to use an eccentric in place of a cam for actuating same. For
holding the thread I use a spiral or other spring, and to keep the bowl upon the
eccentric I also use another spiral or other spring. I, also, use a pad to break
concussion, and nuts and screw for the adjustment.
The second part of this invention relates to a thread "take-up," the lever of
which has a fulcrum either stationary or moveable. The short end of said lever
is joined to a connecting-rod actuated by an eccentric fixed upon upper shaft or
needle-crank disc. The object of having a shifting fulcrum is to give a quicker
movement to the lever at one part of its stroke.
The third part of this invention relates to a means by which a chain-stitch
looper of smaller diameter may be used in such sewing machines as have inter-
changeable stitch devices for the purpose of obtaining various kinds of stitches.
To obtain this result I place a small pinion on, or connected with the driving-shaft
and also another pinion of the same diameter upon the shank or countershaft of
the looper. The arrangement for holding and releasing the looper and countershaft
would be similar to the other looping arrangements as shown in sheet 3, Figures 32
and 33 Specification 10792-1891.
1, SAMUEL BEACH COCHRANE Mechanician of Ivanhoe Lodge 2 Ivanhoe Road
Denmark Park London S.E. do hereby declare the nature of this invention and in
[Price 8d.]

page_text: what manner the same is to be performed to be particularly, described and
ascertained in and by the following statement:-
My improvements refer to the tension device, to the "take up" and to a means
for using a small chain stitch looper or a larger lockstitch hook interchangeably,
in one and the same machine. All the above mentioned devices are applicable to
various styles of sewing machines but especially to that class of such machines
which has interchangeable looping arrangements for producing different varieties
or kinds of stitches.
The first part of this invention is an addition to or modification of the tension
device described in the l'atent Specification No. 10792 of 1891 commencing at
line 55 on page 4 and continued to line 6 on page 5, and shown in Figs. 2 and 10
on sheet 1.
I now propose to make the plunger or piston 25 in two parts, one fitting into the
other, and to use an eccentric in place of a cam for actuating same. For holding
the thread I use a helical or other spring and to keep the bowl upon the eccentric
I use another helical or other spring. I also use a pad to break the concussion
and nuts and screw for the adjustment.
Fig. 1 of the accompanying drawing is a side view and Fig. 2 a vertical cross
section of a suitable form of tension device. The plunger or piston A is made with
a lower stem B which works within a piston C which works up and down in the
cylindrically bored bracket D. The piston C carries in its lower forked end a bowl
or roller E which is acted on by the eccentric F on the upper driving shaft G in
the "arm" of the machine. His a helical spring between the stem B and the
interior bottom of the piston C for keeping the bowl E against the eccentric F.
I is a pad of felt or the like placed against the upper half K of the tension disc
and a pad L may also be placed under the lower half K of the tension disc, for
the purpose of breaking concussion. The upper end of the stem M of the piston A
is screwed and the nut N with check nut O serve for adjustment of the helical
spring which serves to regulate the set tension or the force wherewith the half
discs K and K' normally press the sewing thread between them, while the
eccentric F serves to periodically separate the half discs K and K and thus lets
the thread free, the spring H tending to hold the bowl E against the
eccentric F. By the above improved construction of tension device I obtain a
softer surer and more elastic action suitable for increased speed of the machine.
Fig. 2 shews a modification, the piston C being in this case jointed to the
strap F of the eccentric F thus doing away with the spring H.
The second part of this invention relates to a thread "take up," the lever of
which has a stationary or movable fulcrum. The short end of said lever is jointed
to a connecting rod actuated by an eccentric fixed upon the upper shaft or needle
crank disc.
In case of both lock stitch and chain stitch devices being provided for in the
same machine I use two eccentrics F side by side on the spindle G and make the
lower forked end of the piston C so wide as shewn in the plan view Fig. 2 so that
the bowl or roller E fixed on its pin can be shifted with the latter by a forked
lever E to be acted on by one eccentric, or the other as desired, the two eccentrics
are placed with their eccentricity about opposite. Fig. 2° is a side view.
E is
a spring washer which by the screw E3 can be pressed down upon the lever to hold
it firmly in the one position or the other. The full lines Fig. 2 indicate the
bowl E in one position and the dotted lines in the other.
Fig. 3 is a side view of the "take up" arranged in the outer end of the "arm" of
the machine and Fig. 4 a vertical cross section. The take up lever Q is at its short
end jointed to the ball shaped end of the eccentric rod R which is actuated from
the eccentric S on the upper shaft S. Figs. 5 and 6 are similar views shewing
an arrangement in which the fulcrum of the lever Q is movable the fulerum pin
being in a block Q' which is supported by the spring Q. The object of this
shifting fulcrum arrangement whereby the block will be forced down and compress

page_text: the spring is to give a quicker movement to the lever at one part of its stroke.
Q3 is a screw for adjusting the position of the block Q' by the tension of the
spring Q.
The third part of this invention relates to a means whereby a chain stitch looper
of smaller diameter may be used in such sewing machines that have interchangeable
stitch forming devices for the purpose of obtaining various kinds of stitches. For
this purpose I place a small pinion on or connected with the lower driving shaft
and also another pinion of the same diameter upon the shank or counter shaft
of the looper.
Fig. 7 is an end view and Fig. 8 a plan of such an arrangement. T is a tooth
wheel fixed on the lower driving shaft T, and U is a tooth wheel of the same
diameter fixed on the shank of the small looper V arranged close to the underside
of the needle plate W. The bearing for the looper is in the bracket X which is
fixed to the lug Y in the same hole that serves to attach the ordinary large looper.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is:-
1. The improved construction of tension device described with reference to Figs. 1
and 2 whereby a softer and more conveniently adjustable tension on the thread is
obtained.
2. The improved construction of take up device described with reference to
Figs. 3, 4, 5 and 6.
3. The arrangement of parts described with reference to Figs. 5 and 6 whereby
a small looping device can be employed interchangeably with the ordinary looping
devices.
Dated 1.
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.