IMPROVEMENTS IN SEWING MACHINES
Year: 1874

page_text: PROVISIONAL SPECIFICATON left by Alexander Melville Clark at the
Office of the Commissioners of Patents, with his Petition, on the
17th August 1874.-A communication from abroad by Joseph
Hayes and Lebbeus Wisner Lathorp, both of the Oity, County, and
State of New York, United States of America.
I, ALEXANDER MELVILLE CLARK, of 58, Chancery Lane, in the County
of Middlesex, Patent Agent, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN SEWING MACHINES," to be as
follows:-
This Invention consists of an oscillatory carrier adapted to carry a
commerical spool for the under thread, said carrier working on a pivot
in a manner to have less friction than it would have in à race way, and
being so geared that it can work up to a high speed with less disturbance
to the machine, and by a simpler method of gearing than a reciprocating
shuttle carrier would require. The carrier and shuttle are so contrived
that the shuttle lifts off its bearings on the carrier to some extent by
centrifugal force to pass the thread,

page_text: The Invention also consists of a reciprocating and oscillating looper so
contrived that it opens the loop wide enough for the shuttle of a
commerical spool to pass it freely, also lifts the shuttle either alone or
together with the centrifugal force for the thread to pass the bearings of
the shuttle on the carrier, and forms a kind of race for the shuttle to run i
on while so lifted.
The Invention also consists of the arrangement of the shuttle carrier
and the driving shaft relatively to each other, and the needle that the
carrier is geared directly with the driving shaft by a crank on
the end of the latter and sliding block in a slot of the crank.
And this Invention] also consists of the looper carrying mechanism
contrived to be worked by the same cam groove that is employed to
work the needle arm.
]
The shuttle carrier consists of a metal bar pivoted at the lower end to
a hanger with its upper end which is widened and notched suitably to 1
hold the shuttle against the face plate arranged to swing directly under
the needle plate which is parallel to but a little to the left of the line of
the seam.
The carrier is connected to the driving shaft by a crank and a sliding
block fitted in a vertical slot in the carrier, the wrist pin of the crank a
being fitted in said block. The crank connects with the carrier between
the pivot and the top where the shuttle rests, so that the crank is
considerably shorter than it would have to be if it produced the whole
of the sweep, and being directly connected to the carrier in this manner,
the motion is obtained in the simplest manner.
The shuttle has a recess in each corner of the side opposite to that
which bears on the face plate extending from the bottom to a point a
little short of the top, in which the horns of the carrier fit to hold the
shuttle so that it balances against the race way, and so that it can lift
off the horns readily to pass the thread of the loop between it and said a
horns without catching and straining it. The horns also hold the shuttle
so that it is allowed to lift to some extent by centrifugal force, and by
that means to some extent relieve the thread from being caught between
the shuttle and the horns, but the chief reliance for affording free course
for the thread between the shuttle and the horns is a looper which
moves forward, and by a flange with which it is provided catches the
loop from the needle in a notch at the end, drawing the thread under the

page_text: flange to the rear end, and thus opening the loop for the point of the
shuttle to enter, at the same time it swings down nearly as low as the
bottom of the shuttle, but so that it causes the shuttle to rise a little in
passing over it, thus lifting the front end off from the horn so that the
thread stretching between the point of the looper and the needle will
draw between the shuttle and said horn easily.
The looper remains under the shuttle till the other end is raised in the
same manner and the thread escapes between it, and the other horn
when it goes back to the starting point at the same time withdrawing
from the loop which is then drawn up by the take up. This looper is
swung backward and forward by a crank, and the rise and fall of the
looper is produced by a slotted guide in which a stud pin on the arm of
the looper extending behind the connection with the crank works, and
the crank is worked by the same cam groove by which the needle arm is
worked by said crank being connected with the cam groove by a bar
having a stud pin at one end working in said groove. By arranging the
bar on the side of the cam opposite to the side in which the needle bar is
arranged, the same cam serves to work both the needle arm and the
looper, throwing the looper forward at the same time that it throws the
needle down.
I do not limit myself to the slotted guide for causing the vibrating
motion of the looper, for this may be accomplished by other devices, for
instance, another rocking crank similar to that above mentioned, and
arranged to swing upward when the latter swings forward and downward
when the latter swings backward.