IMPROVEMENTS IN APPARATUS FOR OVERHEAD SEWING
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Alexander Storer at the Office of the
Commissioners of Patents on the 17th August 1880. A communication from
abroad by Louis Bollmann and Josef Bollmann, both of Penzing, near Vienna,
Austria.
ALEXANDER STORER, of Linwood, in the County of Renfrew, Scotland.
"IMPROVEMENTS IN APPARATUS FOR OVERHEAD SEWING." [A communication from
abroad by Louis Bollmann and Josef Bollmann, both of Penzing, near Vienna,
Austria.]
In the Specification to a Patent granted to C. D. Abel, on the 11th August 1879,
for an Invention communicated to him from abroad by Louis Bollmann and Josef
Bollmann, both of Penzing, near Vienna, Austria, was described a machine or
apparatus for effecting "overhead sewing" by the combined action of a revolving
shuttle, a reciprocating needle, and a reciprocating hook. The present Invention
relates to improvements in the said apparatus, whereby its operation is rendered
more rapid and certain, and some of its parts are made more simple and
accessible. For taking up the slack of the thread, the reel and slip clutch for
driving it, as described in the Specification above referred to, are dispensed with,
and a hook lever worked by a cam is employed, this being so arranged and
operated that when the shuttle moves through a certain part of its circular course,
the hook siezes a portion of the thread that passes vertically through the shuttle
and draws it out as a loop, which it afterwards slacks back and releases, thus at the
proper time taking up slack thread and giving it out. In order to secure the
stitching more firmly at each end of the seam, means are provided, according to the
present Invention, whereby the stroke of the feed can be shortened for several
stitches. This is effected by mounting a lever, which can be worked by a treadle,
so as to present its end as an obstruction to the feed slide when it is caused by the
spring to make its back stroke. The feed is also according to the present Invention
arranged so as to dispense with the bracket that carries the presser foot, the fabric
being held between two plates, one of which holds the fabric stationary while the
other is making its back stroke so as to give a fresh feed. One of these plates
carries a smooth nose, round which lies the loop of thread that would otherwise be
strained over the edge of the fabric while the shuttle is passing through the loop
below. Before the latter loop is tightened up the nose of the plate recedes, and
the thread is thereupon tightened over the edge of the fabric. In the former
Specification was described mechanism for closing and opening the eye of the needle,

page_text: which mechanism was somewhat complex and feeble; for it there is substituted,
according to the present Invention, a secondary lever and needle worked by a cam,
the secondary needle sliding along the side of the main needle so as to close and
open its hook eye at the proper times, as determined by the relative movements
imparted to the two needles by their respective cams. The cam for this secondary
needle may be on a shaft driven by gearing from the main cam shaft of the machine.
For facility of access to the shuttle, so that it can be readily removed from and
replaced in its circular race, a portion of the cylindrical side of the race is made as
a door that can be opened, and as the cover of the race is fixed the annular fillet
by which the shuttle was described in the previous Specification to be retained at
its proper level in the race is dispensed with, thus rendering unnecessary the
accurate fitting thereto of the groove in the shuttle.