IMPROVEMENTS IN SEWING MACHINES
Year: 1854

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PROVISIONAL SPECIFICATION left by Richard Archibald Brooman at
. the Office of the Commissioners of Patents, with his Petition, on the
20th March 1854.
I, RICHARD ARCHIBALD 'BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SEWING MACHINES" (communicated to me by a foreigner
residing abroad) to be as follows:-
The first of these improvements consists in so constructing and applying the
friction brake upon the thread that in rapid work on harsh materials the
breaking of the thread at the period of greatest strain is obviated. This im-
provement is particularly applicable to that class of sewing machines in which
the stitch is made by passing the bight or double of a thread through the cloth,
thus forming a loop on the reverse side, through which loop a secondary thread
is to be passed, and the loop then to be drawn tight by the returning motion
of the needle, or by a stitch hook below, or by the joint action of both. To
effect this drawing tight, some check is necessary to the free passage of the
thread from the reel, inasmuch as but for that the stitch hook would not
draw as it should upon the loop only, but would take the thread required for
its next movement as much from the reel as from the last loop, thus leaving a
succession of unfinished stitches. To obviate this, various devices, acting as
permanent or continuous brakes, have been adopted. For light sewing, such
as in muslin or cloth, these have proved sufficient, but when employed upon
harsher material, such as leather, they are inadequate, since to draw back the

page_text: loop in these it is found necessary that the thread should be locked to the
needle or to the needle carrier at all times, except at the precise moment in
each stitch when an amount of thread equal to the length required to make
one perfect stitch is to be fed. This result is accomplished by this Invention
without danger of breaking the thread at the moment of greatest tension.
The second improvement consists in the form of the needle, whereby in
sewing leather or other similar article the hole is so made that the process of
finishing the stitch is greatly facilitated.
And the third improvement consists in so forming the bed or plate on which
the work rests that in turning the work in order to sew in a curve the stitch
may be as perfectly formed as when sewing in a right line.
The first of these improvements is carried into effect by the employment of
an adjustable cam, or its equivalent, in combination with the friction brake,
for the purpose of intermitting the action of the brake upon the thread during
the feed, and thus obviating the danger of sundering the thread in rapid work
during the moment of extreme tension.
The second improvement is effected by enlarging that portion of the needle
which, having entered the material, is to retire from it before the pull upon the
last loop is commenced.
And the third improvement is performed by cutting away the plate on which
the work rests, at the place near to where the stitch is formed, leaving,
however, a support for the cloth during the passage of the needle through it.