IMPROVEMENTS IN SEWING MACHINERY FOR THE PRODUCTION OF 21 FRENCH VEIN " OR HEM-STITCH
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by James Heggan at the Office of the
Commissioners of Patents on the 14th April 1883.
JAMES HEGGAN of Dromore, County Down, Ireland IMPROVEMENTS IN SEWING
MACHINERY FOR THE PRODUCTION OF 21
FRENCH VEIN " OR HEM-STITCH
The Invention has for its object improvements in sewing machinery for the
production of "French vein " or hem-stitch and relates to a novel combination and
arrangement of parts whereby I am enabled to run the machine at a greater speed,
to reduce the wear thereof, to dispense with the use of shuttles and to simplify
and facilitate the learning to work the machine.
In carrying my Invention into effect, I dispense with a cam for operating the
needle slide and employ in lieu thereof an eccentric which operates a rod or link
connected by a universal joint with the lever working the needle slide, I also
dispense with the use of a shuttle and employ in lieu thereof a bobbin and rotating
hook to carry and operate the under thread, such rotating hook being provided
with a tail piece which at the required time acts to hold the bobbin thread away
from the needle thread and thereby facilitate the entrance of the nose of the hook
into the loop thrown out by the needle thread.
By the employment of the bobbin and rotating hook in lieu of a shuttle I am
enabled to employ a rotating shaft to operate the under thread in lieu of a lever
and cam as heretofore required to operate a shuttle. The rotary hook, the needle
slide and the thread handler are operated by a counter shaft which receives its
motion from the driving shaft by suitable gearing.
The thread handler is of the ordinary character and is worked in one direction
by an open cam and in the other by a spring. The rotary hook has its notion
accelerated and retarded at the required times by similar means to those employed
in the Wheeler and Wilson straight needle machine.
I employ an under feed to give all the required motions to the material being
sewn, the feed lever is operated by cains fixed on the driving shaft and is provided
with a pulley resting on the top of one of such cams whilst the pressing foot has
no motion given to it but is always pressing upon the feed foot, so as to keep the
feed lever always against its cam and at the same time prevent vibration.
7077

page_text: The counter shaft, the bobbin holder, that part of the head of the machine
containing the needle slide and the arm for giving motion to the needle are, at the
required times, moved to and fro endwise of the countershaft in order to give
the required traverse to the needle and other parts. This I obtain by mounting
the needle arm on an axis carried by the upper end of a sliding standard which is
also connected to the moving part of the head and the lower end of which is forked
and acts in combination with a clutch on the counter-shaft. This sliding standard
is operated by a cam on the driving shaft acting upon suitable levers on a cross
shaft and in order to facilitate the regulation of the traverse of the needle and
other parts I provide the lever bearing against the cam with adjustable means so
as to regulate the amount of motion given by the cam.
°