IMPROVEMENTS IN SEWING MACHINES
Year: 1873

page_text: LETTERS PATENT to William Wormald and Edmund Dobson, both
of Leeds, in the County of York, Sewing Machine Makers, for
PROVISIONAL SPECIFICATION left by the said William Wormald and
Edmund Dobson at the Office of the Commissioners of Patents,
with their Petition, on the 15th July 1873.
We, WILLIAM WORMALD and EDMUND DOBSON, both of Leeds, in the
County of York, Sewing Machine Makers, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN SEWING MACHINES," to be as
follows:-
This Invention relates to further improvements in sewing machines
for which Letters Patent were granted to William Wormald and Syrias
Henry Hall, dated the 25th day of April, A.D. 1871, No. 1090, and its
objects are:-
"
For the purpose of forming the "lock stitch we attach to the back

page_text: of preventing the spool case being moved backwards while the loop is
being carried over and around the front of the said case, and directed to
the back of the needle by a barb-shaped piece (forming an incline)
secured by screws to the side of the spool holder, and also the said wire
disengages the loop of thread from the hook.
The spool case is held in proper position within its holder by a bolt,
having an enlarged end at or about right angles thereto, which is set and
secured so as to project in front of the spool case; the said bolt is
adjustable so as the better to accomodate the spool case to varying
thicknesses of thread.
When the "cable stitch" is required, the barb-shaped incline is
removed from the side of the spool case holder, whereon the thread will
be carried up the end of the outer portion of the said holder, which
formes a greater incline than the one first referred to, and so causes a
partial dwell of the thread loop until the needle in its descent passes
through the loop which is then drawn up.
The tension on the spool thread is obtained by a "buffer" received
within a cylinder (secured to the spool case) through a hole, in which
cylinder the thread passes, the "buffer" being set to and bearing on the
thread by means of a spiral spring adjusted by screw.
To prevent the machine being started or worked the wrong way we
attach to the end frame or other convenient part an eccentric which
works loosely on a stud. The eccentric bears by gravitation against the
rim of the fly wheel, and so long as the fly wheel rotates in a proper
direction is unimpeded by the eccentric, but on the reverse rotation
being attempted the "throw" of the eccentric (which is faced with
leather or other material) at once locks the wheel and prevents rotation.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Wormald and Edmund Dobson in the
Great Seal Patent Office on the 15th January 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, WILLIAM
WORMALD and EDMUND DOBSON, both of Leeds, in the County of York,
Sewing Machine Makers, send greeting.

page_text: The spool case is held in proper position within its holder by a bolt,
having an enlarged end at or about right angles thereto, which is set and
secured so as to project in front of the spool case. The said bolt is
adjusted so as the better to accomodate the spool case to varying
thicknesses of thread.
When the cable stitch is required the barb-shaped incline is removed
from the side of the spool case holder, whereon the thread will be carried
up the end of the outer portion of the said holder, which forms a greater
incline than the one first referred to (or that is to say, a greater incline
than when the barb is in its place), and so causes a partial dwell of the
thread loop until the needle in its descent passes through the loop, which
is then drawn up.
To prevent the machine being started or worked the wrong way, we
attach to the end frame or other convenient part an eccentric, which
works losely on a stud. The eccentric bears by gravitation against the
. rim of the fly wheel, and so long as the fly wheel rotates in the proper
direction, is unimpeded by the eccentric, but on the reverse rotation
being attempted the throw of the eccentric bears by gravitation against
the rim of the fly wheel (which is faced with leather or other material),
at once locks the wheel and prevents rotation.
Such being the nature and object of this our said Invention, we will
now proceed to describe the same in detail, and in order that the same
may be clearly understood, we have annexed a Sheet of Drawings, and
have marked the same with Figs. and letters of reference.
Fig. 1 is plan (inverted) view of spool case holder and wire or casting
for holding the case in position, and for disengaging the loop thread;
Figs. 2 & 3 are plan and end views shewing the adjustable bolt for
front of spool case; Fig. 4 is a plan view; Fig. 5 is a side view shewing
the barb-shaped incline used for the lock stitch; Fig. 6 shews application
of an eccentric to the fly wheel for purpose above described.
A is the curved wire (or the casting A of similar shape may be
employed) for preventing the spool case holder being moved backwards,
while the loop is being carried over and around the case B, and directed
to the back of the needle by the barb-shaped piece C secured by the
screw D to the side of the spool holder; the part A also disengages the
look thread from the hook (described in Specification referred to). E is

page_text: the bolt adjustable by screws F, F, for holding the front part of the
spool holder, and adjusting it to varying thicknesses of thread.
When the "cable stitch" is required, the barb C is removed, whereon
the thread will pass along the greater incline H, H, and cause the
requisite dwell of the thread loop until the needle passes through,
whereon the loop is drawn up.
To prevent the machine being started or worked the wrong way we
attach to the end frame or other convenient part the eccentric K, which
is free to move on the stud L, and bearing by gravitation on and against
the rim of the fly wheel M. On rotation of the said wheel in the wrong
direction the "throw" of the eccentric at once locks the said wheel
and prevents rotation.
In witness whereof, I, the said William Wormald, for and on
behalf of myself and the said Edmund Dobson, have hereunto
set my hand and seal, this Twelfth day of January, in the year
of our Lord One thousand eight hundred and seventy-four.