Improvements in Thread Cutters.
Year: 1899

page_text: Date of Application, 10th Mar., 1899-Accepted, 29th Apr., 1899
[Communicated from abroad by THE SINGER MANUFACTURING COMPANY, of New
York, United States of America, Sewing Machine Manufacturers.]
Improvements in Thread Cutters.
'
I, JOHN KING MACDONALD, Manager of The Singer Manufacturing Company,
Kilbowie, Dumbartonshire, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:--
This invention has for its object to provide a thread-cutting implement adapted
to cut out, at a single operation, the surplus loose. thread extending between
groups of stitches formed in sewing on buttons, stitching buttonholes forming
bars or stays or doing other analogous work on sewing machines. To this end
the improved cutting implement is formed with double shear cutters or cutting
parts separated from each other laterally, or transverse to their cutting edges, so as
to cut out a piece of thread of any predetermined length by one closing operation
of the tool or implement, the cutting members being preferably pivotally con-
nected and provided with suitable handles so as to be operated similarly to
ordinary shears. One cutting member is preferably formed as a flat tapering
tongue or blade with shear edges at its sides, said tongue working between two
shear blades on the other member of the cutter and placed contiguous to the
inclined sides or edges of said tongue or blade. In cutting out the loose thread or
threads to be removed from between groups of stitches in the work the tapering
tongue member of the cutter is slipped beneath the said thread or threads until
the latter are drawn taut over said tongue at that part thereof the width of which
is equal to the length of thread or threads to be cut out, and the jaws or members of
the cutter are then closed like ordinary shears to sever the thread or threads in two
places up close to the groups of stitches between which the thread or threads
extend. The tapering tongue thus serves as a gauge to ensure the close severing
of the thread or threads up close to the groups of stitches.
In the accompanying drawings Fig. 1 is a side view of the improved thread
cutting implement. Fig. 2 is a plan view of the same, and Fig. 3 section on
line 33 of Fig. 2.
A. denotes the lower blade or tongue member of the cutter the sides of which are
formed as shear edges, said tongue member being preferably integral with a
handle A and tapering as shown in Fig. 2. The upper cutting member com-
prises the blades B attached by screws to arms 6 preferably formed integral with
the handle 131, the two members of the cutter being pivotally secured together by
the pin or rivet c. The blades B are arranged in inclined positions contiguous
to the sides of tongue A which works between said blades. In the form of the
invention herein illustrated the handles of the implement are forced apart, to open
the cutter, by a spring d, and a stop, to limit the opening movement by said
spring, is preferably employed; said stop consisting of the screw e tapped in the
shank a of the tongue A and extending through a slot in the shank be on which the
arms bare formed. When, in the opening movement of the implement, the upper

page_text: side of the shank 6s strikes the under side of the head of the screw
said movement will be arrested, the said screw being so adjusted that
this will occur before the tongue A entirely leaves (or gets out from
between) the blades B.
Instead of using the spring d to open the cutters the
handles A, B, might be furnished with loops or "bows" like ordinary shears
or scissors, as will be understood.
From the foregoing it will be apparent that the surplus threads extending
between groups of stitches, formed for the purpose of attaching buttons, or other
purposes, may be quickly severed in two places up close to the work simply by
inserting the tapering tongue or blade A between the loose thread or threads and
the work and then closing the implement, the said tapering tongue or blade
serving, as heretofore stated, as a gauge to draw the thread or threads taut over
the cutting edges at the sides of said tongue and determine the points of cutting;
and as the said tongue or blade is of different widths at different points in its
length the implement is adapted to cut out different lengths of the thread between
differently spaced groups of stitches, thus always trimming the threads up close
to the work without any special care on the part of the user of the implement.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. A thread-cutting implement comprising two members joined by a transverse
pivot and provided with operating handles, each of said members having two
separated cutting edges or parts, one of said members consisting of a flat tongue
or blade arranged between and working at right angles to the cutting parts of the
other member and adapted to be inserted beneath threads lying close to a yielding
flat surface.
2. A thread-cutting implement comprising two members provided with handles,
and joined by a transverse pivot, one of said members having a tapering tongue or
blade with cutting edges at its sides, and the other of said members having two
shear blades arranged to work contiguous and at right angles to the sides of said
flat tongue or blade.
3. A thread-cutting implement consisting of two pivotally connected members
one of which comprises the flat tongue, or blade A having the handle A', and the
other of which comprises the two separated blades B embracing and working
against the edges of the said tongue or blade A and at right angles to the wider
sides thereof, said blades being connected with the handle B', combined with the
spring d for forcing said handles apart to open the cutters.
4. The herein described thread cutting implement consisting of the tapering
flat tongue or blade A provided with the handle A', the handle B₁, the arms 6 rigid
with said handle B, the blades B attached to the said arms and arranged to embrace
the edges of the flat tongue or blade A and to work at right angles to the wider
faces of the said tongue or blade, the transverse pivot a connecting the two members
of the cutting implement, and the spring d for separating the said handles to
open the cutters.
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents, 62, Saint Vincent Street, Glasgow,
Agent for the Applicant.