IMPROVEMENTS IN BUTTON-HOLE SEWING MACHINES
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by William. Robert Lake, at the
Office of the Commissioners of Patents, with his Petition, on the
21st March 1872.-A communication from abroad by Amos.
Lawrence Wood, of Boston, Massachusetts, United States of
America.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake & Co.,,
Patent Agents, Southampton Buildings, London, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN BUTTON-HOLE
SEWING MACHINES," a communication, to be as follows:-
In certain classes of machines for working or stitching button-holes,
a cloth clamp wheel or disc is used for holding the cloth in which is
made the hole to be stitched, various devices being used to impart
longitudinal and semicircular movements to the said clamp, to present
the cloth along the sides and around the circular eye in succession to
the stitch-forming mechanism.

page_text: In some machines this disc receives its rotation from a pawl acting
on ratchet teeth cut in the edge of the disc, the fault of this contrivance
being that the disc can only be moved in rotation at each intermission
to an amount or angle which is determined by the action of the pawl on
one, two, or more teeth, there being no way in which the movement of
the disc can be made through the space represented by any fraction of
one of the ratchet teeth. This difficulty has heretofore been remedied
by providing a means by which the movements of the discs may be
made of any extent instead of being confined to fixed divisions of a
circle like those of ratchet teeth, and one object of the present Invention
is to accomplish the desired result by a more direct application of the
feed mechanism to the rotating clamp disc.
Another part of this Invention relates to means for automatically
effecting the change in the feed movement for the eye part and slit part
of the button-hole respectively, and the said Invention embraces an
improved method of effecting the same result, as also an improvement in
the construction of the friction feed devices. The said Invention consists
partly in making the clamp disc with provision for the direct application
thereto of the griping devices of a friction feed mechanism, and in com-
bining therewith the mechanism for operating the friction feed pawl,
the said mechanism and the disc preferably have directly connected with
them the devices by which change of feed movement for the eye and
slit is automatically effected, such change being effected by directly
combining with the friction feed pawl two stops, with one or the
other of which the pawl is brought into contact on the back stroke
to regulate or determine the extent of its forward or feed movements,
the pawl strikes one stop at each back movement while either side
of the slit is being worked, and the other stop is automatically
brought into position to be struck by the pawl; when the eye is reached
each stop determining the extent of feed and its variation for the eye
and slit parts respectively, the change from stop to stop being auto-
matically effected both to change from one side of the disc to the eye,
and from the eye to the opposite side of the slit.
Another part of the said Invention relates to the thread interlocking
and loop spreading devices, and consists in spreading and interlocking the
loops of the needle and those of the thread carrier, by the reciprocating
movements of one bar and slide, and by the eccentric rotative move-

page_text: ments of the carrier and the looper the position of the stationary loop
spreading beak in rotation thereto, the passage of the points of the
looper into the under thread at the needle side, and of the needle thread
into the loops formed thereby being rendered more certain.