Improvements in Sewing Machines.
Year: 1897

page_text: Date of Application, 14th Dec., 1897-Accepted, 19th Feb., 1898
in the City of Philadelphia, State of Pennsylvania, United States of America,
Manufacturer.]
Improvements in Sewing Machines.
I, William Phillips Thompson, F.C.S., M.L.M.E., of The Agency for Foreign
Patent Solicitors, 322, High Holborn, in the County of Middlesex, 6, Lord Street,
Liverpool, and 6, Bank Street, Manchester, both in the County of Lancaster, and
Lower Temple Street, Birmingham, in the County of Warwick, Civil Engineer,
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 is more particularly of that class of sewing machines known as
overseamers, and it is adapted for forming an overedge seam of one or more threads,
as in binding the edge of a fabric, uniting the edges of fabrics, stitching button holes,
covering rings, and analogous uses.
The principal objects of this invention are, first, to provide a machine in which
the thread is handled directly, without transfer; second, to draw off only so much
of the thread as is required to form the stitch, and thus to avoid the use of a
take-up device; third, to permit of the use of a single strand thread, such as is
used in weaving the fabric, for forming the single thread overseam, and for either
or both threads in forming the double thread overseam, thus avoiding the harsh
edge finish in soft knit garments produced by the use of hard twist thread required
for machines now in use; fourth, to avoid the use of a welt guide, by adapting the
looper to control the edge of the fabric and regulate the length of the bight;
fifth, to provide a machine of greater simplicity of construction and operation than
has heretofore obtained, which is capable of attaining unlimited speed, whereby the
defect of low speed, of machines heretofore used, is overcome; and, sixth, by the
peculiar shape and motion of the looper, to overcome the tendency to drop stitches
and to improve or facilitate the casting off of the loop, which are defects of machines
heretofore used.
The machine is provided with a reciprocating needle and a peculiarly formed
curve-pointed looper, which latter is caused to oscillate around the edge of the
fabric, in unison with the reciprocations of the needle therethrough, the looper
describing in its travel more than half a circle, catching the needle thread below
the fabric and forming a loop thereof which it carries over the edge in the
operation of carrying the looper thread through this needle loop and into position
to be engaged by the descending needle above the fabric. The looper thread
being caught by the descending needle, the looper recedes in unison therewith and
drops through or casts off the needle thread loop, whereby the stitch is formed.
The point of the looper is inclined to the plane of its motion, to facilitate catching
the thread from the needle below the fabric, and is directed or pointed toward the
outside of the curve which it describes around the edge of the fabric, the said point
forming an obtuse angle with the looper shank. The peculiar shape and motion
of the looper causes no more thread to be drawn from the needle than is required to
cover the edge of the fabric, and leaves no more of its own thread engaged with
the needle than is required to form the purl, whereby the use of a take-up device

page_text: is avoided and the use of soft single-ply thread is made possible. The comparatively
straight looper, in receding, drops out of the loop which it carries over the edge of
the fabric without exerting any pull thereon, as a consequence of its peculiar shape
and motion, thus avoiding dragging down the stitch.
The nature and characteristic features of this invention will be more fully
understood from the following detailed description taken in connection with the
accompanying drawings, of which-
Figure 1 is a front elevation of a machine embodying the main features of the
invention Figure 2 is a top or plan view of the same; Figure 3 is an elevation
of the left end of the machine! Figure 3 is a perspective view of the looper:
Figure 4 is a view of the link mechanism for operating the looper: Figure 5 is a
plan view of the throat-plate: Figures 6, 7, 8, 9 and 10' are view's illustrating the
relative positions of the needle and looper in forming the double thread overseam:
and, Figures 11, 12, 13, and 14 are views illustrating the relative positions of the
needle and looper in forming the single thread overseam.
Referring to the drawings, the frame 1 is provided with bearings 2 and 3, and
the shaft 4 is journalled in these bearings, being driven by the belt pulley 5.
A bell-crank 6, journalled on an arbor 7 supported by the frame, is connected
with and oscillated by the shaft 4 by means of the pitman 8 which has an eccentric
connection 9 with the shaft and a ball and socket connection 10 with the bell-crank.
The horizontal arm 11 of the bell-crank is connected with and reciprocates the
needle bar 12, an adjustable block 13 secured to the needle bar being connected to
the crank arm by the link 14 which is pivoted to the block at 15 and to the arm
at 16.
The needle bar reciprocating vertically in the bearings 17 and 18, the presser
foot 19 and bar 20, the elevating lever 21, the depressing spring 22, and the feed
mechanism 23, all operate in the usual manner.
The vertical arm 24 of the bell-crank is connected with and oscillates the looper 25,
which is secured to the link 26; for the upper end of the link 26 and an arm 27,
pivoted to the frame at 28, are pivoted together at 29, and the lower end of the link
is pivoted at 30 to the long arm of a lever 31 which is fulcrumed in the bearing 32
and has its short arm connected with the bell-crank by a link 33, pivoted at 34
and 35.
As the revolving shaft 4 reciprocates, the needle 36, through the described inter-
mediate mechanism, it will also reciprocate the looper 25 in unison therewith, by
means of the described link mechanism and intermediate connections, the looper
being caused to describe a curve whose upper and lower limits cross the needle in
its vertical reciprocations.
The looper 25 is formed with a plain shank and a point 43, which lies on the
convex side of the curve described by the looper in its movement, is inclined to
the plane of the looper's movement, and forms an obtuse angle with the looper
shank, as illustrated in Fig. 34, the looper being provided with eyes 47 and 48
which receive the thread 46.
It will be observed that the action of the looper is positive and direct, for in the
operation of seizing the thread, forming the loop and carrying it, the looper advances,
instead of receding as is usual, which obviates a chief defect of overseaming
mechanisms now in use, while the peculiar link motion carries, the looper through
its several positions at such angles that it may be made comparatively straight."
The plane of the looper, and the mechanism connecting it with the bell-crank, is
. inclined to the vertical and to the line of action of the needle, as illustrated in
Fig. 3, and consequently the looper will pass in front of the needle in the upper
limit of its path, and to the rear in the lower limit, or to the right and to the left
respectively in the position of the mechanism shown in Fig. 3.
The throat plate 37 is provided with a slot 38 through which the needle
reciprocates, and a slot 39 through which the looper reciprocates, the two slots
being separated by a tongue 40 about which the stitch is formed and from which
it readily slips as the material is advanced by the feed mechanism 23.

page_text: In forming the double thread overseam, the needle thread 41, fed from a spool
placed in any suitable position, is first carried by the needle through the
fabric 42 and the slot 38, the needle and looper mechanism then
occupying the position. illustrated in Figs. 4 and 9. As the needle rises the
thread between its eye and the fabric slackens, and the looper point 43, passing. to
the right and close to the rear of the needle, catches the thread and forms the
loop 44 which is carried around the tongue 40 and the edge of the fabric through
the successive positions illustrated in Figs. 10, 7, and 6. As the looper rises in
unison with the needle, it slips through the loop 44, Fig. 6, and draws down the
part 45 of the looper thread which part is caught by the needle, as it descends close
to the rear of the looper, as illustrated in Fig. 7. The looper, descending with the
needle, readily draws out of the loop 44, as illustrated in Fig. 8, and the stitch is
thus formed.
It will be observed that the needle thread is caught positively by the point of
the advancing looper and merely pushed to the edge of the fabric, where by reason.
of its positive engagement with the loop and as its shape and motion are such that
its shank approximately follows the path described by its point close around the
edge of the fabric, the looper shoots through the loop without drawing it out, as
illustrated in Fig. 6. When the descending needle has caught the looper thread
the looper recedes and, as its shank follows the path of least resistance to the loop
surrounding it and as its point forms an obtuse angle with the shank, the needle
thread loop is shed without pulling off more than is required to form the stitch.
It is evident that the looper, which has been carried past the point of the elevated
needle only sufficiently to permit the needle on descending to engage the looper.
thread, will on receding leave only so much of its thread as is necessary to form
the stitch. The successive stitches are formed by a repetition of this operation.
In forming the single thread overseam, the same mechanism is employed.
found desirable, however, to form a notch in the looper at the base of the hook,
to prevent the loop from slipping down on the looper as is required in forming the
double thread seam.
It is
Referring to Figs. 11, 12, 13, and 14, when the needle has passed through the
fabric and the throat-plate slot 38, and is rising, the looper 50, passing to the rear
of the needle, engages the slackened thread and forms the loop 52 which is caught
in the looper notch 51, as illustrated in Figs. 13 and 14. As the needle rises, the
looper carries this loop around the tongue 40 and the edge of the fabric, from the
position shown in Fig. 14 to that shown in Fig. 11. The needle, now descending,
passes close to the rear of the looper and enters the loop 52, Fig. 12, which the
descending looper casts off, the parts resuming the position shown in Fig. 13, and
the stitch being thus formed.
As the point of the looper travels in a path close to the edge of the fabric and
substantially coincident with the position to be occupied by the loop, merely pushing
the loop into its desired position, where it is caught by the descending needle, and
on receding dropping out of the loop, only so much of the thread is drawn off as is
required to form the stitch. The successive stitches are formed by a repetition of
this operation.
As the path of the looper follows closely the line around the edge of the fabric
occupied by the loop, no more thread is drawn off than is required to form the
stitch, which obviates the use of a take-up device. As the shape of the looper and
its action are such that no take up device is required, a single strand thread may be
employed in both the needle and the looper, for both the single and double thread
seam. The looper shank, striking close to the throat plate tongue, guides the edge
of the material, and regulates the length of the bight, it being evident that its
action will be to roll in any excess of material between the needle and the point.
which it strikes.
As the loop is caught positively around the looper, which advances in carrying
it around the edge of the fabric, it is impossible for the loop to slip off or be

page_text: dropped until the looper begins to recede, when the peculiar shape of the looper
permits it to be readily cast off.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is:
1. In a sewing machine, in combination, a reciprocating needle, a curve-pointed
looper which oscillates in a curved path and has its point directed outwardly from
said curved path, a link to which said looper is attached, an arm having one end
pivoted to said link and the other end pivoted to a fixed support, an oscillating
lever fulcrumed in a fixed support and pivoted to said link, a throat-plate, and
mechanism connecting said needle and looper mechanism, whereby they are adapted
to operate in unison, substantially as and for the purpose specified.
2. In a sewing machine, in combination, a reciprocating needle, a throat-plate
having a tongue, an oscillating curve-pointed thread-carrying looper, means to
cause said looper to enter the thread loop formed by said needle upon the under side
of said throat-plate and to carry it to the edge of said plate. and passing farther
thereinto to yield a loop of its own thread to form a purl on the edge or border of
the fabric, said means comprising a link to which said looper is attached, an arm
hving one end pivoted to said link and the other end pivoted to a fixed support, an
oscillating lever fulcrumed to a fixed support and pivoted to said link, and mechan-
ism connecting said needle and looper, as specified.
3. In a sewing machine, a curve-pointed looper provided with two eyes, said
looper oscillating in a curved path and having its point directed outwardly from
said curved path, a link to which said looper is connected, an arm having a movable
connection with said link at one end and with a fixed support at the other end,
a lever having one of its ends connected with said link, and means for actuating
said lever thereby causing said looper to oscillate, substantially as and for the
purpose specified.
4. In a sewing machine, in combination, a revolving shaft, a pitman connected
with and oscillated by said shaft, a bell-crank connected with and oscillated by
said pitman, a needle connected with and oscillated by said bell-crank, a link, and
a looper fixed thereon, an arm having one end pivoted to said link and the other
end pivoted to a fixed support, a lever fulcrumed to a fixed support and having
one end pivoted to said link, and a second link connecting said fulcrumed lever
with said bell-crank, substantially as and for the purpose specified.
5. In a sewing machine, in combination; a reciprocating needle, a throat-plate,
a looper and means to oscillate it in a curved path through said throat-plate and
around the edge of the fabric, said looper comprising a plain shank and a point
which is turned toward the outside of said curved path and forms an obtuse angle
with said shank, and mechanism connecting said needle and looper, whereby they
are operated in unison, as specified.
6. In a sewing machine, in combination, a reciprocating needle, a throat-plate, a
looper and means to oscillate it in a curved path through said throat-plate and
around the edge of the fabric, said looper comprising a plain shank and a point
which is turned toward the outside of said curved path and forms an obtuse angle
with said shank, said point being also inclined to the plane of said curve, and
mechanism connecting saïd needle and looper, whereby they are operated in unison,
as specified.
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.