IMPROVEMENTS IN SEWING MACHINES
Year: 1885

page_text: I HARRY GAMWELL, of Wavertree Road, Liverpool, in the County of Lancaster,
Machinist, do hereby declare the nature of the said invention for "IMPROVEMENTS
IN SEWING MACHINES " to be as follows:-
This invention relates to further improvements on the class of sewing machines
referred to in the Specifications of my previous patents N° 4711 of 1883 and
No 5765 of 1884.
In the machine shewn in the drawings accompanying the Specification of Patent
No 4711 of 1883, the mechanism for actuating the feed bar is not perfect in as
much as the bar does not move to and fro perfectly horizontally, but has a slightly
inclined movement, and the motion at each end of the bar does not exactly
correspond, and further during the operation of sewing and more particularly at
the commencement when the threads are loose, unless great care on the part of the
operator be observed, there is danger of the loop through which the shuttle passes
becoming too long, and consequent thereon, loose or uneven stitches in the sewing.
The object of my present improvements is to obviate these defects.
The feed bar is actuated by a cam on the driving shaft through a connecting
rod, and a rocking lever receiving motion by the action of the cam on the con-
necting rod. It has been my practice hitherto, as seen in the drawings referred to,
not to place the head or socket of the connecting rod in which the cam revolves
on the axial line of the rod, but rather to one side of such line, and to place the
rocking lever over to one side of the. machine connecting it only at one end of the
feed bar. I now make the head or socket of the connecting rod so that its axis
will coincide with the axis of the rod, and place the rocking lever so that its axis
will be in the same vertical plane with the axis of the driving shaft and the shuttle
shaft. The rocking lever is attached to the connecting rod with a universal or
other suitable joint, and the fulcrum of the lever is placed about mid-way between
the connecting rod and the feed bar, the lever branching out into a fork at the end
nearest to the feed bar, each end of the fork engaging with the respective ends of
the feed bar transmitting a uniform motion thereto. On the foot of the presser
which keeps the cloth or material in contact with the teeth of the feed bar, I place
a teusion device to hold the thread and prevent the ends being drawn down with

page_text: the needle and thus forming too big a loop for the shuttle, and in order to prevent
the shuttle nose catching and pulling on the thread with the same result, and to
enable it to pass smoothly through the loop, I cut the metal away on the under
side so that the point passes through for a considerable distance before any increase
of thickness is appreciable on the thread. The delivering eye of the shuttle, I make
oblong preferably a radial or cam shaped slot, and place it as near to the bottom of
the shuttle as convenient, this allows the shuttle to move to that extent further
than it carries the thread, and prevents too great a quantity of thread from being
withdrawn from the bobbin.
WP. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.

page_text: I, HARRY GAMWELL of Wavertree Road Liverpool in the County of Lancaster
Machinist do hereby declare the nature of this invention for 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 further improvements in the class of sewing machines
referred to in the specifications of my previous patents N° 4711 of 1883 and
No 5765 of 1884.
In the machine shown in the drawings accompanying the specification of patent
N° 4711 of 1883, the mechanism for actuating the feed bar is not perfect, in as
much as the feed bar does not move to and fro perfectly horizontally, but has a
slightly inclined movement, and the motion at each end of the bar does not
exactly correspond, further during the operation of sewing, and more particularly
at the commencement when the threads are loose, unless great care on the part of
the operator be observed, there is danger of the loop through which the shuttle
passes becoming too long, and consequent thereon loose or uneven stitches in the
sewing. The object of my present improvements is to obviate these defects.
The improvements are shown in the accompanying drawings in which
Figure 1 is sectional elevation of part of the machine.
Figure 2 end elevation of connecting rod.
Figure 3 plan looking from below of the rocking lever and feed bar drawn to a
reduced scale.
Figure 4 front elevation of shuttle..
Figure 5 back elevation of same.
Figure 6 presser foot with thread tension attached thereto.
A is the driving or main shaft of the machine B the cam or eccentric thereon,
from which motion is conveyed to the feed bar. C the connecting rod conveying
motion from the eccentric B to the rocking lever D and through it to the feed
bar E. By referring to the drawings of my previous patent N° 4711 of 1883, it
will be seen that the head or socket of the connecting rod therein referred to as I
is placed to one side of the axial line of the rod, and is fitted with a cranked
connecting piece at the other end, so as to communicate with the rocking lever L,
placed at one side of the machine. That arrangement allows of the rocking lever
being attached or connected at one end of the feed bar only, with the result that
as the other end of the feed bar is carried by an inclined slot and pin, a perfectly
horizontal motion is not obtained. I now make the connecting rod C with the
head or socket c so placed that its axis will coincide with the longitudinal axis of
the rod, and the connecting link or joint c², preferably as far as possible on the
same axial line. The departure from this shown in the accompanying drawing is
to allow the centre of the socket c¹ to lie in the same vertical plane as the
longitudinal axis of the driving shaft. The cast frame F of the machine shown
is not perpendicular, and the movement of the bracket G in the slot H would
otherwise throw the socket c' out of the required position.

page_text: I place the rocking lever D so that its axis will be in the same vertical plane
with the axis of the driving shaft and the shuttle shaft, and attach it to the
connecting rod C with a universal or other suitable joint; the fulcrum of the
lever being placed in the position shown, or about midway between the connecting
rod and the feed bar. The rocking lever D as it approaches the feed bar E
branches out into a fork, each end of the fork engaging with one end of the feed
bar E at d and e transmitting uniform reciprocal motion thereto, both horizontal
and vertical, irrespective of the direction in which the main may revolve.
On the foot of the presser I which keeps the cloth or material in contact with
the teeth of the feed bar I place a tension device J to hold the thread before
stitching is commenced, and prevent the loose end being drawn down by the
action of the shuttle upon it. A barrel i is formed on the presser foot in which a
small spring is placed and two discs are attached by means of a screw to the
outside of the foot. In order to allow the shuttle to pass smoothly through the
loop without dragging on the thread and to enable the thread to pass easily over
the nose of the shuttle I cut away or reduce the metal on the underside as shown
at . The delivering eye L of the shuttle I make oblong, preferably a radial or
cam shaped slot, and place it as near to the bottom of the shuttle as convenient,
this allows the shuttle to move to the extent of the length of the slot, further than
it carries the thread, and prevents too great a quantity of thread being withdrawn
from the bobbin.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that
what I claim is
1st. In a sewing machine, the use of a forked rocking lever, placed in the central
vertical plane of the machine, for actuating the feed bar in combination with a
vertical connecting rod, substantially as described and shown.
2nd. The combination with the presser foot of a tension device for holding the
thread, substantially as and for the purposes described.
3rd. The improvements in circular oscillating shuttles for sewing machines,
which consist in (a) cutting away or reducing the metal on the underside of the
nose, (as shown at ) and (b) forming the delivery eye of an oblong preferably
radial slot placed at or near the bottom of the shuttle substantially as and for the
purposes described.
WP. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.