IMPROVEMENTS IN SEWING MACHINES
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office
of the Commissioners of Patents, with his Petition, on the 29th December
1859. A communication from abroad by James Snow Goodridge, of
Grenoble, in the Empire of France.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North
Britain, Gentleman, do hereby declare the nature. of the said Invention for
"IMPROVEMENTS IN SEWING MACHINES," a communication from abroad by James
Snow Goodridge, of Grenoble, in the Empire of France, to be as follows:-
This Invention relates to a peculiar construction and arrangement of
mechanism for producing a helicoidal or over-cast stitch similar to that used
in sewing kid gloves, the thread employed being in lengths or needlefulls in lieu
of being supplied in a continuous manner from a spool or bobbin, as is usually
the case in sewing machines.
According to this Invention the fabric to be sewn is held in a vertical
position between a pair of gripping jaws, the edges of which are indented for
the guidance of the sewing instrument, similar to the jaws employed by glove
makers. The feed motion is obtained from a rack and pinion, actuated by a
pall and ratchet wheel driven from a vertical driving shaft, the lateral traverse
obtained being imparted to the holding jaws which carry the fabric with them.
The sewing instrument consists of a hook similar to an ordinary crochet hook,
carried by a horizontal slide, which is worked to and fro by the combined
action of a cam and blade spring. The horizontal arm which carries tho
sewing hook is capable of vertical adjustment in slides, so that the position of

page_text: the hook as regards the indented edge of the cloth holders may be adjusted
with the greatest nicety. The sewing hook having been pushed through the
fabric, draws back with it on its return stroke the thread which it has caught,
and which has been held in a proper position for that purpose on the front
side of the fabric by a vibrating hooked holder, which has three motions
imparted to it, namely, a rising and falling motion, a lateral vibratory or
swinging motion, and a horizontal motion towards and from the fabric; these
several movements being requisite for the seizing of the thread, and the holding
of it in a proper manner to be caught by the sewing hook. The thread is
drawn through the fabric in the form of a loop by the sewing hook, and this
loop is then caught by a revolving hook carried on the circumference of a
revolving disc driven by mitre wheels from the main vertical driving shaft
before referred to. As this book revolves, it expands or draws out the loop
until the loose end of the thread is entirely pulled through the fabric, leaving
the thread in a single thickness therein. This loose thread is provented from
becoming entangled and interfering with the mechanism by being retained
between a pair of friction pads or spring plates, which are covered with a pile
fabric or other rough substance capable of exerting a slight drag or friction
upon the thread. Whilst the thread is being drawn through by the action of
the revolving hook, the sewing hook has again penetrated the fabric, and is in
a position for recoiving the thread for the next stitch, which is now gripped
between the pads, and moved slightly forward by the action of a pusher rod
against one of the spring pads or plates, thereby increasing the friction to such
an extent that on the vibrating hook again seizing the thread, it will exert a
sufficient pull to tighten the previous stitch. Above the sewing hook, and
carried on the same horizontal arm therewith, is a short horizontal stud, over
which the thread is passed by the lateral and downward movement of tho
vibrating hook, and after its descent it moves again in a lateral direction below
the stud, and also below the sewing hook, thereby bringing the thread again
under the influence of the barb of that instrument. By the employment of
the stud above referred to, the strain of drawing the loop is removed in a great
measure from the sowing hook, for the distance between this hook and the
stud over which the thread is passed is about equal to the length of loop to be
drawn out by the sewing hook, and as this stud recedes with the sewing hook it
gives off enough slack thread to form the loop in lieu of the entire thread being
drawn forward through the fabric by the sole pull of the sewing instrument.
The opening of the cloth holders is effected by a treadle and levers, so that the
attendant can readily adjust the cloth therein or remove it when finished. The
end of the vibrating hook has a helicoidal groove formed in it, so that the

page_text: thread can lay in it without its folds overlapping each other. The compound
motion of this hook is derived from two cams on the shaft which carries the
revolving hook before referred to, one of these cams imparting a vertical
motion to the bearings which support the axis of the vibrating arm or hook,
and the other imparting, through a lever arm a rocking or partial rotatory
motion to the axis in its bearings, whilst at the same time a longitudinal
motion is imparted to this axis, causing it to slide lengthwise in its bearings
by means of a bevelled edged disc, fast on the axis, acting against fixed
inclines carried in a bracket secured to the upper part of the framing. In
order to ensure the proper opening of the loop so as to enable the revolving
hook to lay hold of one of its threads, it is proposed to cause the sewing hook
to work through a piece of cloth or other suitable material, which, when the
hook makes a slight forward movement to slacken the loop after it has drawn
it through, will bear against the apex of the loop, and compel it to expand or
open out. The sewing hook is guided on its approach to the fabric by working
in a guiding slot or groove made transversely in the surface of a horizontal bar
extending across the front of the machine.