IMPROVEMENTS IN SEWING MACHINE SHUTTLES
Year: 1876

page_text: LETTERS PATENT to William Bown, of Birmingham, in the County of Warwick,
Manufacturer, for the Invention of "IMPROVEMENTS IN SEWING MACHINE
SHUTTLES."
PROVISIONAL SPECIFICATION left by the said William Bown at the Office
of the Commissioners of Patents on the 2nd October 1876.
WILLIAM BOWN, of Birmingham, in the County of Warwick, Manufacturer.
"IMPROVEMENTS IN SEWING MACHINE SHUTTLES."
The object of this Invention is to provide a ready means for threading up the
shuttle and adjusting the friction on the thread.
To avoid the inconvenience of passing the end of the shuttle thread through holes
or eyes in the shuttle to obtain the tension I provide a bar with a free end (cut out
from and forming part of the shell of the shuttle) under which I lay the thread us
it comes from the bobbin, and I then draw it over to the other side of the shuttle
and lay it in the notch of a sliding pressure spring fitted inside the shell and secured
thereto by a screw or pin which passes through a slot in the side of the shuttle and
carries an index or pointer. This pressure spring overlies a thread hole or slot
which is entered by a saw cut made in the edge of the shell. The thread passing to
the back of the pressure spring enters the hole in the side of the shuttle through the
saw cut and passes thence out of the shuttle. As the thread is drawn out of the
shuttle it is exposed to the friction of the spring, which presses it against the side of
the shuttle, and in proportion as the length of the friction surface is increased or
diminished so is the tension on the thread reduced or increased. On the outside of
the shuttle I propose to make marks or graduations over which the pointer before
mentioned will be moved to adjust the spring to the required position, so as to give
more or less tension according to the nature of the work in hand.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Bown in the Great Seal Patent Office on the 29th March
1877.
WILLIAM BOWN, of Birmingham, in the County of Warwick, Manufacturer.
"IMPROVEMENTS IN SEWING MACHINE SHUTTLES."
The object of this Invention is to provide a ready means for threading up the
shuttle and adjusting the friction on the thread.
To avoid the inconvenience of passing the end of the shuttle thread through holes
or eyes in the shuttle to obtain the tension, I provide a bar with a free end (cut out
from and forming part of the shell of the shuttle) under which I lay the thread as it
comes from the bobbin, and I then draw it over to the other side of the shuttle and
lay it in the notch of a sliding pressure spring fitted inside the shell and secured
thereto by a screw or pin which passes through a slot in the side of the shuttle.
This sliding pressure spring overlies a thread hole or slot, which is entered by a saw
cut made in the edge of the shell. The thread passing to the back of the sliding
pressure spring enters the hole in the side of the shuttle through the saw cut, and
passes thence out of the shuttle.
In the accompanying Drawing, Fig. 1 is a view of the under side of the improved
shuttle drawn on an enlarged scale; Fig. 2 is an end view of the same; Fig. 3 is a
cross section taken in the line 1, 2, of Fig. 1; Fig. 4 is a face view; and-Fig. 5 a
view of the top side of the shuttle.
a is the bar formed out of the under side of the shell of the shuttle by slotting the
shell from its edge near the rear end of the shuttle to a distance extending forwards
slightly beyond the bobbin b, and parallel with the edge of the shuttle. In the
particular description of shuttle here shewn the edge of the bar a is cut away or
rebated for nearly its whole length (see Fig. 1) to allow space for the free traverse
of the shuttle thread between the bar and the shuttle race.
In the top side of the shuttle a T shaped slot c is made (see Fig. 5) commencing
from the edge of the shell. This slot is covered on the inner side of the shuttle by
a sliding pressure spring d (see the partial longitudinal section, Fig. 6) which spring
is secured to the shuttle by means of a screw e that passes through a longitudinal
slot f made in the side of the shuttle. The sliding pressure spring is fitted with a
longitudinal enlargement or projection (see Fig. 5a) which enters the slot f of the
shell and is made to slide freely therein. A tapped hole is made in this projection
to receive the screw e, which serves to hold the pressure spring to the side of the
shuttle. A diagonal slot g is made in the outer edge of the sliding pressure spring
d to form a guide for the thread which is laid in the slot and carried forward to the
Tshaped slot c. To facilitate the entrance of the thread into the slot g the wedge-
shaped portion of the pressure spring is bent slightly inwards, as shewn at Fig. 4.
The thread as it leaves the bobbin or reel b is looped over the free end of the bar a
as shewn best at Fig. 3. It is then passed across the shuttle and under the sliding
pressure spring d to the T shaped slot c, whence it emerges from the shuttle and is
laid under the ordinary elastic thread guide h as seen at Fig. 4. It will now be
understood that as the thread is drawn out of the shuttle it is exposed to the
friction of the sliding pressure spring d, which presses it against the side of
the shuttle, and in proportion as the length of the friction surface between the
spring and the shell is increased or diminished by the sliding backwards or
forwards of the sliding pressure spring d in the slot f, so is the tension on the
thread reduced or increased. On reference to Fig. 4 it will be clearly seen that by
moving the sliding pressure spring d, say to the right, the pressure and consequent
tension on the thread will be proportionately increased and vice versa. On the
outside of the shuttle I propose to make marks or Figures (as indicated at Fig. 5)
to either of which the screw e may be moved to adjust the sliding pressure spring d
to the required position, so as to give more or less tension according to the nature of
the work in hand.

page_text: In applying my improvements to the various description of shuttles that do not
admit of any interference with the edge of the face side of the shuttle to provide
space for the free traverse of the thread over the bar I adopt a modification, shewn
at Figures 7 and 8, where Fig. 7 is an underside view of the shuttle, and Fig. 8 a
face view of the same. In this instance the free ended bar a is formed out of the
shell of the shuttle by making in the shell thereof two longitudinal and parallel cuts
(which extend slightly beyond the ends of the bobbin or reel) and join at or near
the rear end of the shuttle. The bar thus formed I taper at its end and give it a
bend inwards that it may be the more readily reached by the loop of thread that is
to be laid over the bar. In other respects this shuttle will be similar to that above
described.
Having now set forth the nature of my Invention of "Improvements in Sewing
Machine Shuttles," and explained the manner of carrying the same into effect, I
wish it to be understood that under the above in part recited Letters Patent,
I claim,
Firstly. The shell bar a of the shuttle, with the open or free end for facilitating
the threading up of the shuttle.
Secondly. The sliding pressure spring or plate d for regulating the tension on the
thread.
Thirdly. The index placed along the edge of the slot f of the shuttle for indicating
the amount of tension on the thread as it passes from the shuttle or under the nip
of the sliding pressure spring.
In witness whereof, I, the said William Bown, have hereunto set my hand
and seal, this Twenty-eighth day of March, in the year of our Lord One
thousand eight hundred and seventy-seven.
DANH
WILLIAM DOWN. (L.B.)