IMPROVEMENTS IN SEWING MACHINES AND IN THE MEANS FOR PRODUCING A BINDING OR BUTTON-HOLE " STITCH THEREIN
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Edwin Powley Alexander at the
Office of the Commissioners of Patents on the 20th February 1883. Com-
municated to him from abroad by Charles H. Crawford of the City County
and State of New York in the United States of America
EDWIN POWLEY ALEXANDER of 36 Southampton Buildings in the County of
Middlesex Fellow of the Institute of Patent Agents " IMPROVEMENTS IN SEWING
MACHINES AND IN THE MEANS FOR PRODUCING A BINDING OR BUTTON-HOLE
"
STITCH THEREIN A communication to me from abroad by Charles H. Crawford
of the City County and State of New York in the United States of America
This invention relates to that class of sewing machines used for over-seaming
and cat-stitching and consists of a machine and certain details and appliances
some of which are adapted also for use with other machines whereby to form the
stitches rapidly without noise and abrupt jarring movements to secure a ready
manipulation and adjustment of the parts an automatic variation of the stitch and
an automatic presentation of the edges of a button hole to the fabric.
The invention further relates to a binding or button hole stitch formed by
interlocking two threads as hereinafter described and comprises the following
combinations or arrangements of parts.
A block pivotted to the head and carrying the needle bar in combination with
a vertical crank shaft and a lever connected at one end to the said block and at the
other to a crank. A horizontal driving shaft provided with a crank and eccentric
in combination with a rod for conveying motion to the devices operating the needle
bar and with a rock shaft connected so as to operate the feed devices and having
a crank arm and a connecting rod extending to the eccentric. The combination
of the horizontal shaft and devices connected therewith to impart a vertical motion
to the needle bar and devices to operate the feed appliances and a shaft geared
with the said horizontal shaft to revolve at half the speed of the latter and
appliances connected with this shaft to operate the thread carrier and impart a
horizontal motion to the needle bar. The combination with a reciprocating eye
pointed needle of a needle plate provided with a projection and a curved double
pointed thread carrier having an eye near one end and a lip near the other and
devices for operating the needle and carrier. The combination with a feed cam
disc of a mitre wheel gearing with a mitre rack on the disc a shaft supporting
the said wheel and a flanged disc and a hub forming part of a rock lever and dogs
biting the flange of a separate disc and fitting sockets in the hub. The combination
of the rock lever and feed devices and the rock shaft carrying a loose arm arranged
opposite the end of the rock lever and an attached arm and a regulating screw
extending through the said arm. The combination with a clamp plate and with
the loose arm hung to the rock shaft carrying a rod of a stop plate and devices for

page_text: shifting it from the clamp plate. The combination of a clamp plate revolving and
sliding on the work-plate a slide having a bearing on the edge of the clamp plate,
and the stop plate bearing on the slide and arranged to be thrown into or out of
action by the movements of the slide. The combination of the clamp plate feed
devices and intermediate appliances constructed to be operated by said plate
whereby the feed is increased as the plate is turned to present the eye of the
button hole to the needle. The combination of the clamp plate provided with a
pin a stationary work-plate having a slot and a cam disc revolving below the
work-plate and provided with a series of similar separate grooves at equal
distances apart in the face of the disc and adapted to receive the end of the said
pin. The combination of the said cam disc having a series of similar separate
grooves each diverging from the centre towards the edge of the disc the work and
clamp plates feed devices for revolving the disc intermittently and a supplemental
device for rotating the disc by hand. The combination of a stud with a sleeve
and pivotted jaws carried by the said sleeve, a spring bearing on the sleeve and a nut.
The combination with the said clamp plate of jaws hung to a stud also a stud and a
cam lever having slots receiving pins on the jaws and a cam sleeve bearing with
its lower cam edge on lugs and supporting the said cam lever.
The button hole stitch is formed by the joint operation of a needle a double
pointed circular reciprocating thread carrier and a lip or spreader on the underside
of the work plate near the needle opening.
-The needle first penetrates the cloth carrying a loop of its thread with it. The
needle then slightly rises so as to loop its thread and the point of the carrier with
a second thread enters between the needle thread and the needle. The needle
then rises.
On the next descent of the needle which is opposite the edge of the cloth it
passes between the second thread and the carrier so that as the latter is turned the
carrier thread is lapped round the needle and finally drawn through the loop of
needle thread.
-
The needle then rises slightly to spread its thread so that the end of the carrier
will pass between the needle and the thread catching the latter and forming a
new loop of needle thread which is left upon the carrier as the needle rises.
A lip on the carrier prevents the loop of the needle thread from slipping back
and the continued revolution of the carrier brings one side of the loop against
the hook or spreader which catches and opens the loop until by the continued
revolution of the looper it is spread below the needle so that the latter at its next
descent will enter the loop.
The motion of the carrier is then reversed and as it turns the loop of needle
thread slips off upon the needle and is drawn up by the take-up devices while
another loop is formed at the side of the needle and penetrated by the point of
the carrier and the above operations are then repeated.
By these means and operations is produced a stitch peculiarly adapted for
buttonhole and edge seaming both threads being formed into surface loops which
by properly regulating the tension may be thrown to the edge of the fabric to
form a heavy bead thereon.
This results from throwing a loop of needle thread through a loop of carrier
thread and then locking the needle thread loop by another loop of the same thread
and locking the latter loop by a loop of carrier thread and so on, the alternate
stitches in binding crossing the edge of the fabric.
In edge binding may be used an edge thread which is caught in and secured by
the over edge stitches in the usual manner.