IMPROVEMENTS IN SEWING MACHINES
Year: 1883

page_text: LETTERS PATENT to Sydney Pitt of Sutton in the County of Surrey, for
an Invention of "IMPROVEMENTS IN SEWING MACHINES " communicated to
him from abroad by Lebbeus Baldwin Miller and Philip Diehl both of
Elizabeth in the County of Union and State of New Jersey United States of
America
COMPLETE SPECIFICATION filed by the said Sydney Pitt at the Office of
the Commissioners of Patents on the 27th March 1883.
"
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN SEWING
MACHINES communicated to me from abroad by Lebbeus Baldwin Miller and
Philip Diehl both of Elizabeth in the County of Union and State of New Jersey
United States of America.
This Invention is especially applicable to single thread or chain stitch sewing
machines and its objects are to provide a simple durable and efficient mechanism
for producing what is known as the "twisted" chain-stitch and also to provide
means for simultaneously sewing two or more seams, and varying and adjusting
the same so as to increase or decrease the distances between such seams.
In the Drawings Figure 1 represents a side view of the frame of a sewing
machine with the mechanism through which the needle bar and the hook or looper
receive their respective motions. Figure 2 is an under view of the same machine
illustrating the looper driving mechanism and Figures 3 to 6 inclusive are enlarged
detail views of the hook or looper showing its construction, modes of attachment
and adjustment and of operation, Figures 3 and 4 shewing especially a loop over
the hook, held open in the notch e the hook being on its forward motion and
ready to enter the next loop, and Figures 5 and 6 shewing the hook on its return
movement, the deflected point el having caught the side of the loop. The usual
vertically reciprocating motion is given to the needle bar (and consequently to the
needle) from the main driving shaft A preferably by means of a crank on said
shaft with which the bar is directly connected by a link, but the invention can be
effectively and advantageously applied and used if a reciprocating motion be
obtained by any of the methods commonly used in sewing machines. The looper
is driven as follows. A portion of the main shaft A, bent to form a crank, carries
the connecting rod B, the rock shaft C hung in bearings c² c² is provided with
an arm c, to which arm, near said rock shaft as shown in Figures 1 and 2, this
connecting rod B, is pivotted; a link c' is pivotted to the outer end of said arm c,

page_text: and the other end of this link is pivotted to the crank d, of the looper rock shaft D.
As the main driving shaft revolves an oscillating motion is communicated to the
arni c, and by means of the link c¹ and crank d, an increased oscillating motion is
given to the parallel rock shaft D which turning in its bearings d¹¹ serves to
drive the looper. By making the arm c, longer than the crank d, and also longer
than the distance between the centres of the shafts C and D an increased oscilla-
tion can be obtained in the rock shaft D being a little more than half of a revolution
alternately in each direction which is found advantageous and important in
.properly forming the twisted chain stitch. As the rock shaft C can also be used to
give the lifting and falling movements to such a feed it has been retained although
it is evident that the same result can be obtained by pivotting the arm c to a lug
or projection and using it as a lever of the third class.
The twisted chain stitch, is formed in the following manner. As the needle,
having reached its lowest point, begins its ascent and forms a loop the hook or
looper E being then on its forward movement (as in Figures 3 and 4) catches this
loop on its point e, and continuing such movement carries it down until the
point e' of said looper E also passes through the loop. The looper then commences
its return movement, and as its point c' is bent or deflected beyond the line of the
descent of the needle (see Figure 5) it also, on this return movement, catches one
side of the loop which has been carried down by the point e, and twisting it
carries it down until it rests in the retaining notch e² as shewn in Figure 4
There.it is held open during the next descent of the needle and until the hook
again advances and its point e, seizes a succeeding loop, when it escapes from the
notch e² and as this ensuing loop is drawn down by the point e, through the loop
first caught and twisted, the said first loop escapes over the point e¹ is drawn up,
and the stitch thus completed.
In order to multiply seams of this character without adding to or changing the
driving mechanism, and by addition only of a needle clamp and needles and loopers
to correspond with the number of seams required, the bar d² which carries the
looper, is simply extended and the. required number of loopers secured thereon by
the set screws as shewn.
This method of securing the looper or loopers enables them to be adjusted in any
desired position and by making a corresponding adjustment of the needles, the
stances between the seams may be regulated at will.
di I claim as the Invention.
First. A sewing machine looper adapted to be oscillated and cooperate with a
reciprocating needle substantially as described whereby a twisted chain stitch will
be produced.
Second. A sewing machine looper adapted to act in connection with a recipro-
cating needle, and provided with actuating mechanism substantially as described
whereby it receives an oscillating movement.
Third. A sewing machine looper provided with mechanism whereby it receives
an oscillating motion and also provided with means for adjustment substantially as
and for the purposes set forth.
Fourth. Two or more adjustable loopers adapted to receive oscillating motion
and to cooperate with an equal number of reciprocating needles substantially as
and for the purposes set forth.
+
In witness whereof I the said Sydney Pitt have hereunto set my hand and
seal this seventh day of March in the year of our Lord One thousand eight
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