IMPROVEMENTS IN OVER- STITCHING MACHINES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Jean Elie Richard at the Office of the
Commissioners of Patents on the 9th January 1882.
JEAN ELIE RICHARD, a Citizen of the United States and residing in New
York City, United States of America, Machinist. "IMPROVEMENTS IN OVER-
STITCHING MACHINES."
This Invention relates to an overstitching machine which is especially adapted
to sewing the "sweats or sweat-leathers into hats, and as such it will be herein
described; but it is also adapted to sewing carpets, gloves, furs, and to other uses
where overstitching is required.
The following are some of the peculiar features of the machine.
The arm bearing all the operative parts (except the feed) turns on the main shaft
as a centre without disarranging the mechanism, and said mechanism may be
operated with the arm upraised as well as when it is down. A straight needle is
employed and this needle may be set to operate at any angle desired within limits.
An angular presser foot is employed which is fixed rigidly with reference to the
path of the needle, and the necessary adjustment for different thicknesses of
inaterials is accomplished by adjusting the feed-wheel. The looper twists the
thread in forming the loop and thus makes a compact stitch which resembles hand
work.
A hollow bed or base for the machine is mounted on a table being by preference
hinged thereto and provided with a spring catch to hold it down. Mounted fixedly
on the rear end of the bed is a forked post in which the main driving shaft is rota-
tively mounted, and on this shaft are mounted the usual driving pulley and
fly-wheel, and the three operating cams, namely the needle driving can, the looper-
driving cam, and the feeding cam or eccentric. The arm of the machine, which
bears the stitch forming mechanism, the presser foot, the roller-foot and the sweat-
holder is hung or mounted on a boss on the fixed post and swings concentrically
around the main shaft being provided with a suitable spring catch to hold it up
when its free end is raised and to lock it fast when down.
To the free end of the arm is rigidly but adjustably fixed the angular presser
foot which is arranged to engage the angle formned by the brim with the crown of a
hat in sewing in the sweat and to serve as an abutment for the yielding feed wheel

page_text: which is mounted in the hollow base of the machine and projects through the front
of the same.
This wheel is mounted on a vertical axis and its upper side forms a
bed for the brim of the hat to rest upon, while its periphery is roughened and takes
against the exterior surface of the crown to feed the hat along. The feed wheel is
actuated intermittently by means of a clutch strap which surrounds it, the ends of
which are connected by means of toggle links that are connected by a rod and
lever with a rocking lever the free upper end of which bears against the feeding-
eccentric on the main shaft. When this eccentric presses back the end of the
rocking lever the toggle links cause the clutch strap to first grip the feed wheel,
and then to rotate it. As the eccentric passes on a spring retracts the parts, first
relaxing the clutch strap. The length of the stitch is regulated by a screw which
adjusts the rock-lever to or from the feeding eccentric. The feed wheel is pressed
up to the angle formed by the brim and the crown of the hat by means of an
adjustable spring, and the wheel may be thrown up or down and in or out by
means of cams operating in connection therewith. The roller foot, which bears
against the sweat as it is being stitched fast, is hung to the end of the arm below
the presser foot on an elastic ball-and-socket joint, whereby it is caused to adjust
itself to the irregularities of the surface to a sufficient extent.
The sweat holder is arranged to hold a strip of the sweat leather in the form of
a roll. The roll is inserted in the holder where it rests upon a spring support, and
one end is led out through a guide wherein a slight elastic pressure is kept upon it
to keep it up and prevent its feeding too easily. The holder is adjustably mounted
on the free end of the arm of the machine.
The feed wheel and length of stitch being properly adjusted, the hat is placed in
position, its brim horizontal and resting on the feed wheel, the arm brought down
and latched, and the end of the sweat drawn from the holder and arranged in place
behind the presser foot and roll.
I will now describle the mechanism for forming the stitch. This I will preface,
however, by saying that the needle bar and looper are mounted on a plate which is
secured to the arm by screws which pass through curved slots, whereby the angle
of the line of travel of the needle and looper inay be set at various angles with
respect to the remainder of the parts, the needle being required to travel more
nearly horizontal for some kinds of overstitching than for others.
The needle bar, bearing the straight needle fixed in its end is mounted to reci-
procate in bearings and derives its motion through a connecting rod which bears a
pin and roller that engages the groove in the needle operating cam on the main
shaft. The thread comes from a spool on a spool holder mounted on the arm
and passes through a tension regulating device and a take up lever. This tako up
lever swings on a pin at its ceutre and is held in space normally and elastically by
a flat spring, and it is actuated by a piu on the needle bar which plays over a multi-
faced cam on the rear end of said take-up lever, whereby the slack thread is taken
up at the proper time.
The looper is a hook-shaped device with twisted or screw neck, which is
pivoted to the looper bar so as to have a slight lateral movement, being held to
place normally by a spring, and operated by wiping over a projection as the looper
bar plays. The looper bar has a longitudinal movement and being hung at its
middle on the upright end of a rock-lever pivoted to the machine arm, it will be
seen that the looper has a movement forward and back in a vertical arc, and at the
same time a movement in a horizontal arc. The looper bar is reciprocated by the
looper actuating cam through the medium of a connecting rod similar to that
employed for the needle.
Having described the placing of the hat and the sweat to be stitched therein, and
the general construction of the stitch forming mechanism I will now describe the
operation of stitching in the sweat.
The machine being set in motion the needle advances and pierces obliquely
through the angle of the hat and the upper edge of the sweat. As it nears the
end of its out stroke it passes close to the left of a plate fixed on the presser foot.

page_text: This plate when the needle draws back slightly to form a loop in the thread causes
the loop to be thrown out wholly to the left of the needle. After this loop has
been formed the needle is arrested for an instant to enable the looper to insert its
curved tip through the same. At the instant this is fairly accomplished the needle
starts back and actuating the take up lever causes the latter to draw the loop snugly
around the twisted neck of the looper. The latter bearing the loop, now draws
back, moving in an arc inclined at about forty-five degrees so as to pass clear over
the edge of the sweat and around the needle. As the looper reaches the end of its
back stroke it drops down upon the hat brim in or close to the path of the needle
where it rests for an instant until the needle, which has been advancing again,
inserts its point through the loop passing in its movement close to the neck of the
looper and on through the loop of thread as it is spread open by the looper. The
moment the needle passes through the loop and its point enters the material of
the hat the looper begins its forward movement. This movement is similar to the
backward movement being in an inclined arc so that as the hook lifts out of the
loop and drops it, it will also pass around the needle. The moment the looper
drops the loop, the take up lever acts to draw up the surplus thread and make
a tight stitch. The same movements are gone over in making each successivo
stitch.
It will be understood that the 3 actuating cams will be constructed and set
to drive the needle, looper, and feed at the proper times, and in the proper way,
the feeding being accomplished while the needle is free from the material as in all
sewing machines. The movement of the looper twists the loop as it is carried back
and the screw-shaped neck of the looper serves to run the loops off the looper-
hook, as will be readily understood.