Improvements in Lock-stitch Shuttle Sewing Machines.
Year: 1897

page_text: Date of Application, 23rd Feb., 1897-Accepted, 15th May, 1897
[Communicated from abroad by THE SINGER MANUFACTURING COMPANY, of New
York, United States of America, Sewing Machine Manufacturers.]
Improvements in Lock-stitch Shuttle Sewing Machines.
I, WILLIAM HARVEY INSLEE, 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, as communicated to me, to be particularly
described and ascertained in and by the following statement :-
In the operation of vibrating shuttle sewing machines in which the shuttles are
loosely held in the carriers, to permit the loops of needle thread to pass freely
over the shuttles, more or less noise is produced by the rattling of the shuttles
in the carriers and against the driving horns of the latter and which alternately
come into contact with the opposite ends of the shuttles. My invention has for
its object to obviate this objection by providing a shuttle-operating mechanism for
vibrating shuttle machines which will be silent in operation, and in which the
shuttles will always be positively held and controlled. In carrying my invention
into effect I provide the curved face of the shuttle-race with a supporting rib,
which is preferably of dove-tailed or other undercut form in cross-section, and
which enters a corresponding groove formed in the curved outer face of the shuttle
the weight of which latter is thus mainly supported by said rib. The shuttle is
moved back and forth by a driver which swings in the arc of a circle of smaller
radius than the circle from which the arc of the shuttle-race is described, so that
as the said driver vibrates to and fro its two horns will be alternately engaged
with and disengaged from the shuttle, thus holding the latter positively at all
times as it is moved back and forth against its race. The shuttle shell provided
with holes into which the points of the said horns can enter, said horns being of
such length that the entering one will engage the shuttle before the withdrawing
one leaves it, and thus the shuttle will always be in positive engagement with the
driver as well as with the shuttle-race, and from this construction it results that the
shuttle can be noiselessly operated, even at the highest rates of speed.
In the accompanying drawings Figs. 1 and 2 are bottom views of a Singer
vibrating shuttle machine embodying my invention, the parts being in different
positions in the two views. Fig. 3 is a detail section on line 3-3 of Fig. 1.
A denotes a lever or rocker pivoted on the stud a fixed to the work-plate B and
provided with a crank-arm c connected by a pitman d with an operating crank-arm e
which, in the machine herein shown, is rigid with a vertical rock-shaft operated from
a crank on an upper rotating driving shaft, this being the usual construction in the
well-known Singer vibrating shuttle machines. The rocker A has a second army'
with which the shuttle-carrier has heretofore been rigidly connected but to which, in
my present invention, the shuttle-driving lever G is pivotally attached by a pin or
screw 9, said lever having the horns h and h', to engage the shuttle I, and the
tail-piece g¹ provided with a slot g² entered by a pin or screw g³ fixed to the work-
plate B.
As
When the rocker A is moved back and forth the lever G will be moved bodily with
it, but will at the same time be caused to vibrate more or less on its pivot g; the
amount of this vibration depending on the shape of the slot g² and the position of the
stationary screw 93 beneath the head of which the tail-piece slides freely.
the lever G, moving bodily back and forth with the rocker A, is thus vibrated on its
pivot 9,
its horns and will be automatically engaged with and disengaged from
the holes or recesses in the shuttle into which they enter, the horn h being lifted from
the shuttle, as shown in Fig. 1, when said shuttle is performing the first part of its
TD
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page_text: forward movement, to permit the forward part of the shuttle to pass through a loop of
needle thread, and the horn being lifted from the shuttle, as shown in Fig. 2, to
permit the loop of needle thread to escape over the heel of the shuttle. Thus the
shuttle driving lever G, the outer end of the operating arm of which describes a
partial circle of a smaller radius than the radius of the circle from which the arc of
the curved shuttle race J is struck, is so moved relative to the path in which the
shuttle travels as to cause the alternate engagement and disengagement of the horns
of the shuttle driver and shuttle just described, the horn h engaging the shuttle just
before the horn h¹ is disengaged therefrom so that the shuttle is always in positive
engagement with its driver.
The shuttle race J is provided with a rib or flange j, preferably of dove-tail or other
undercut form in cross-section, and the shuttle I is provided with a groove of
corresponding form to receive said rib or flange which thus serves to hold the shuttle
in positive connection with its race and to support the main weight of the shuttle.
As the said rib or flange enters the said groove in the shuttle with a close sliding fit,
and as the said shuttle is, as above described, always in engagement with its driver,
any rattling of the shuttle, against the race or driver, when in operation, is effectively
prevented, and the shuttle is vibrated or moved back and forth smoothly and quietly,
even at the highest rates of speed.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination with a curved shuttle-race and a shuttle fitted to run against
the same, of a two-horned vibrating shuttle-driver which swings from or on a centre
or pivot nearer to the said race than the centre from which the arc of the shuttle-race
is described, and means for vibrating said shuttle driver on its pivot and for moving
it back and forth bodily; whereby said shuttle driver will be so moved relatively to
said shuttle as to cause its horns to be alternately engaged with and disengaged from
said shuttle as the latter is moved to and fro.
2. The combination with a curved shuttle-race and a shuttle fitted to run against
the same, of a two-horned shuttle-driver, a rocker or vibrating lever to which said
driver is pivoted between the fulcrum or centre of motion of said rocker or lever and
said shuttle-race, and means for vibrating said driver on its pivot and for moving it
back and forth bodily; whereby the horns of the driver are caused to be alternately
engaged with and disengaged from said shuttle as the latter is moved to and fro.
3. The combination with a curved shuttle-race having an undercut rib and a shuttle
fitted to run against the same, and having a groove into which said rib closely fits, of
a two-horned shuttle-driver, a rocker or vibrating lever to which said driver is pivoted
between the fulcrum or centre of motion of said rocker or lever and said shuttle-race,
and means for vibrating said driver on its pivot and for moving it back and forth
bodily; whereby the horns of the driver are caused to be alternately engaged with
and disengaged from said shuttle as the latter is moved to and fro.
4. The combination with a curved shuttle-race having an undercut rib and a shuttle
having a curved faced grooved to receive said rib, of a rocker or vibrating lever, a
two-horned shuttle-driver pivoted to said rocker or lever at a point between the pivot
of the latter and said shuttle-race, said shuttle-driver having a tail-piece provided with
a slot, and a fixed pin entering said slot and serving to vibrate said driver on its pivot
to cause its horns to be alternately engaged with and disengaged from said shuttle as
said driver is carried back and forth bodity by said rocker or lever.
Dated this 22nd day of February 1807
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents, 62 St. Vincent Street, Glasgow,
Agent for the Applicant..