off the barb and is entered by the
threaded needle, completing the stitch.
_Of Button Hole Machines_.--The mechanism of button hole machines is so
intricate, that I can only attempt on this occasion to partially elucidate
the construction of one of them, recently introduced, namely, Singer's,
which automatically cuts, guides, and stitches the work.
[Illustration: FIG. 9.]
Fig. 9 exhibits the stitching made by this machine upon the edge of the
button hole. Fig. 10 represents the right and left hand loopers and loop
spreaders, and for the stitch making. They rock from right to left with an
intermittent motion obtained from a cam. The left hand looper carries the
under thread and interweaves it with the upper, forming the stitch,
originally invented, I believe, by Mr. George Fisher, of Nottingham, and
reinvented for the button holing machine by D.W.G. Humphreys, of
Massachusetts, U.S.A., in 1862. The loop spreaders are moved by a roller
carried upon the looper frame. Fig. 11 exhibits the feeding arrangement,
both sides of the feed wheel, the driving lever, and the shape of the path
given to the carrying clamp by the heart cam cut in the upper surface of
the feed wheel. The picture on the screen represents the upper portions of
the machine, exhibiting the conveying clamp, the to and fro dipping motions
of the needle bar, and the parts conveying motion to the arrangements
beneath the bed plate. These are shown in Fig. 12, and represent the feed
and looper cams, the feeding and looper levers, and the stitch forming
mechanism already shown. A most ingenious device in this machine is the
arrangement for automatically lengthening the throw of the feed while
stitching around the eye of the button hole. It is effected by means of a
cam, which imparts more or less leverage to the feed arm by the
intervention of a "shipper" lever, hinged to the feed lever itself. The
space of time at my disposal obliges me to recommend a personal examination
of the machine itself, to fully understand its various motions and its
action in working a button hole.
[Illustration: FIG. 10.]
[Illustration: FIG. 11.]
[Illustration: FIG. 12.]
Mention may be made of Singer's special button hole machine for making the
straight holes used in linen work, and in which a shuttle is employed. Of
Wheeler & Wilson's ingenious button hole machine for the same purpose, I am
enabled to show a diagram, in which it will be observed that the feeding
arrange
|