Improvements in Sewing Machines.
Year: 1893

page_text: Date of Application, 5th Oct., 1893
Complete Specification Left, 5th July, 1894-Accepted, 5th Oct., 1894
PROVISIONAL SPECIFICATION.
Improvements in Sewing Machines.
I, HARREY MOORE, of High Street, Wellingborough in the County of
Northampton, Machine Agent, do hereby declare the nature of this invention to
be as follows:-
This invention for improvements in sewing machines relates to lock stitch
machines in which the hook or shuttle carrying the loop round the bobbin or
thread case is continuously rotated; and has for its objects to render the point and
throat of the hook readily renewable, to design the thread case and hook in such
manner that the thread case is retained in the hook and to hold the thread case
stationary in the hook from the back so as to leave the front side perfectly open, to
shape the book and thread case in such manner that the loop is readily drawn off,
and to simplify the feed motion.
The point and throat of the hook are detachable and are secured to the body by
guide pins and set screws, the heads of which fit into recesses in the body.
The thread case is formed with an external flange working in a corresponding
groove in the hook, and is inserted in the hook before the point and throat are
secured to the body. It is fixed on a hollow shaft driven by a link and crank arm
from a pin in a disc fixed on the end of a shaft mounted eccentrically to the hollow
shaft in such manner that the motion of the hook is slow when taking the loop.
The disc is hollow and has an inwardly projecting flange on its front end. A stop
shaft having a forked arm at its front end is passed through the hollow shaft from
the hook end, and at its back end enters the hollow disc and is cut away so that it
just bears and fits a portion of the inner diameter of the disc flange and as the disc
is eccentric to the shaft it is held stationary whilst the disc and the hook rotate.
A projection on the back of the thread case is held between the forks of the arm
of the stop shaft and so holds the thread case stationary.
The whole side or part of the hook in front of the point is cone or similarly
shaped and is cut away towards the point so as to allow the thread to readily pass
off and to reduce the amount of slack thread required to form the loop and the
back half of the thread case is rounded off with a similar object. The root of the
point of the hook is inclined towards the front so as to throw the loop towards
the cone part of the hook. The thread case being supported by its circumference
is thus adapted to take a ball of twine.
The feed plate is subjected to two motions; one up and down vertically,
imparted by an eccentric on the hollow hook shaft through a strap having an
elongated hole; and the other forwards and backwards horizontally, imparted from
an eccentric on the main shaft of the machine through a system of shafts and levers
provided with a suitable device for varying the amount of motion and thus the
feed.
Dated this 5th day of October 1893
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.

page_text: Improvements in Sewing Machines.
I HARREY MOORE, of High Street, Wellingborough in the County of
Northampton, Machine Agent, 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 for improvements in sewing machines relates to lock stitch
machines in which the hook carrying the loop round the bobbin or thread case is
continuously rotated; and has for its objects to simplify the hook mechanism to
render the point and throat of the hook readily renewable, to design the thread
case and hook in such manner that the thread case is retained in the hook and to
hold the thread case stationary in the hook from the back so as to leave the front
side perfectly open, to shape the hook and thread case in such manner that the loop
is readily drawn off, and to simplify the feed motion.
The hook is fixed on a hollow shaft driven from the main shaft and the bobbin
or thread case is held stationary by a rod passing down the hollow shaft.
The front part and point and throat of the hook are detachable and fit on the
body and are secured by set screws, the heads of which fit into recesses in the
body.
The thread case is formed with an external flange working in a corresponding
groove in the hook and is inserted in the hook before the front part is secured to
the body. The hollow shaft carrying the hook is driven by a link and crank arm
from a pin in a disc fixed on the end of a shaft mounted eccentrically to the hollow
shaft in such manner that the motion of the hook is slow when taking the loop.
The disc is hollow and has an inwardly projecting flange on its front end. A stop
shaft having a forked arm at its front end is passed through the hollow shaft from
the hook end and at its back end enters the hollow disc and is cut away so that it
just bears and fits a portion of the inner diameter of the disc flange and as the disc
is eccentric to the shaft it is held stationary whilst the disc and the hook rotate.
A projection on the back of the thread case is held between the forks of the arm
of the stop shaft and so holds the thread case stationary.
The whole side or part of the hook in front of the point is cone or similarly
shaped and is cut away towards the point so as to allow the thread to readily pass
off and to reduce the amount of slack thread required to form the loop and the
back half of the thread case has a spiral shaped cast off. The root of the point of
the hook is inclined towards the front so as to throw the loop towards the cone part
of the hook. The thread case being supported by its circumference is thus adapted
to take a ball of twine.
The feed plate is subjected to two motions; one up and down vertically imparted
by a cam on the shaft carrying the disc; and the other forwards and backwards
horizontally imparted from an eccentric on the main shaft of the machine through
a system of shafts and levers provided with a suitable device for varying the amount
of motion and thus the feed.
In the accompanying five sheets of illustrative drawings
Fig. 1 is a sectional elevation of a sewing machine constructed according to this
invention, and
Fig. 2 is a part central vertical section showing the rotary hook and its driving
mechanism and the thread case.
Fig. 3 is a part sectional front end elevation of the same.
Fig. 4 is a cross section through the hook driving mechanism showing the parts
in the positions they occupy when the hook is taking the loop from the needle.

page_text: Fig. 5 is a similar view to Fig. 4 showing the parts in the positions they occupy
when the loop is being drawn off the hook.
Fig. 6 is a longitudinal section showing the manner in which the stop shaft is
held stationary by a rotating disc, and Fig. 7 is a cross section of the same.
Figs. 8 and 9 are front views of the rotary hook showing it in two different
positions, and
Fig. 10 is a sectional back end elevation showing the feed mechanism.
Figs. 11 to 18 are side and front elevations of different positions of the hook
showing the manner in which the stitch is formed.
The rotary hook a is fixed on a hollow shaft b mounted in a bearing e' depending
from the cloth plate c. The hollow shaft bis driven from a countershaft d' itself
driven from the main shaft d as clearly shown. The countershaft d' is parallel to
the shaft but eccentric to it, and the shaft b is driven by means of a link e and
arm el from a stud e' fixed to a disc d' mounted on the end of the countershaft d¹.
The eccentricity of the shaft d' causes the hook a to be driven at a variable speed
so that when the hook is taking the thread from the needle, the speed is slow.
The front side and point a' of the hook is made detachable and fits on the main
body and is secured by the screws a' the heads of which are countersunk. The
hook is formed with an internal groove a serving to hold the thread case f
Between the point and the heel is secured by the screws a' a looper shield a which
acts on the thread on the back side of the needle so that when the needle is raised
slightly to form the loop the shield forces the loose thread on the back side of the
needle through the eye so that the loop is formed on one side only of the needle and
is consequently larger.
The thread case is made in two parts ff¹ adapted to fit one on the other and be
secured together by a bayonet catch and to contain a ball of twine without reel
or other support. It is formed with an external and central dange f corresponding
to the internal groove a' of the hook and in which it works. A portion of the
flange is removed at the top of the case so as to form an opening and hook f³.
The rear side of the case is also provided with a helical or inclined cast off f
extending from the point or hook to the outside of the case near the bottom.
In order to insert the thread case fin the hook a it is necessary to remove the front
side and point a¹ of the hook. In order that a ball of twine may be inserted or
changed in the thread case without removing it from the hook the front part f' is
pierced with two holes fo and fits on the back part which carries the flange f
The front part is removed by a key whose ends are adapted to fit into the holes fo
to turn this part to release from the bayonet catch. The ends of the key may be
hooked to draw this part 1 off the part f, or the key may have a central hook
adapted to pass into a central hole f' in the front f' of the case.
The thread case f is maintained stationary in the hook a by means of the stop
shaft g mounted in the hollow shaft b and provided at its front end with a forked
arm 9 projecting within the hook and engaging with a projection f on the back of
the thread case. The back end of the stop shaft projects beyond the end of the
hollow shaft 6 into a chuck gl whose end engages with the disc d² which is made
hollow as shown in Fig. 6 and provided at its front end with an inwardly projecting
flange d. The chuck g is notched at 9' to receive the flange d³ which on account
of its eccentricity keeps the chuck and thus the shaft g stationary whilst it rotates
so that it can be
itself. The stop shaft is secured in its chuck by two set screws
readily inserted in place from the front and adjusted to the required longitudinal
and circumferential position and to facilitate the removal of the hook when.
required. In order to provide for the renewal of the wearing part of the disc d²,
the flange d' is made part of a separate piece d³ sliding in a groove across the face
of the disc and secured in place by the screw d'.
The front side of the hook a is cone shaped as shown at a and is cut away
towards the point so that the loop readily passes off the hook when this part is
remote from the needle as shown in Figs. 15 and 16 and the amount of slack thread
required in forming the stitch is reduced. The throat of the point of the hook is

page_text: inclined towards the front as shown in Figs. 1 and 13 so as to throw the thread at
the back side of the loop on to the cone part of the hook. The helical or inclined
cast off of the thread case causes the loop to readily slide over its back.
The stitch is formed as follows:-The point of the hook takes the loop from the
front of the needle as shown in Figs. 11 and 12 the end 1 being fixed in the work
and the end 5 going to the needle. The hook then carries the loop against the end
or hook f' of the flange of the thread case and the part, 1, 2, 3 of the thread then
remains stationary whilst the hook in rotating draws the thread from the end 5;
and lays it beyond the point 3 on the thread case at the root of the cast off f' as
shown in Figs. 13 and 14 to the point 4 the thread then passing up from the
point 4 by the throat of the hook and over the cone part of the hook to 5 and the
needle. It will be seen that the portion of the thread nearest the work is now at
the back of the thread case whilst the portion nearest the needle is thrown by the
hook to its front. When the hook has made about half a revolution as shown in
Figs. 15 and 16 the take up lever begins to draw up the thread and the part 3 to 4
begins to pass over the back of the thread case whilst the part 4 to 5 passes over
the front of the hook. Figs. 17 and 18 show the loop just leaving the hook having
completely passed round the thread case and thus enclosed the locking thread.
The loop leaves the thread case at the top at the part f³ where the flange is
removed.
The feed plate is subjected to two motions one up and down and one forwards
and backwards. It is secured to an arm ³ whose back end is caused by a spring h
to bear on a roller mounted on an arm fixed on a shaft carrying another
arm having a bifurcated end engaging with a cam d' on the shaft d'. The
cam d is so formed that the arm and consequently the feed plate is raised just
before the commencement of the feed and lowered again just after the end of the
feed. The other end of the arm is pivoted to an arm fixed on a countershaft i
so that as the shaft i is vibrated the arm and feed plate are moved forwards
and backwards horizontally. The countershaft i is actuated from an eccentric / on
the main shaft d, the eccentric rod / being jointed to one end of a lever m pivoted
at m' to the main frame of the machine. The lever is formed with a curved roller
race in which works a roller n mounted on one end of a link n' connected to an
arm on the countershaft i. A vibratory movement is thus given to the shaft i
and in order to vary the amount of this movement the link n' slides freely in a
sleeve n³ pivoted to the head of a screw n³ sliding in a hollow stud n screwing into
the frame. A nut n° fits on the end of the screw n³ and bears against the end of
the stud n and so determines the distance of the roller n from the fulcrum m¹ of the
lever m and consequently the motion of countershaft i and thus the horizontal
motion of the feed plate h. The screw n is clamped in position after the feed has
been adjusted by the screw nº.
In order to tie off the end of a seam the motion of the feed plate is arranged so
that it can be reversed with respect to the other parts of the mechanism. This is
effected by pulling out the nut n° to its fullest extent when the roller n is drawn in
its race to the opposite side of the fulcrum. A small adjustable set screw n
screwing into the frame comes in contact with the head of the screw n³ and
determines the new position of the roller and thus the length of stitch. At the
end of a seam the nut is pulled out and a few stitches made as the feed plate
works in the opposite direction.
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
1 claim is
1. In lock stitch sewing machines a hook, a shaft on which the hook is mounted,
a bearing for supporting the shaft, and mechanism for rotating the said shaft from
the main shaft and a thread case supported at its circumference within the hook
substantially as set forth.
2. In lock stitch sewing machines a hook adapted to be rotated, a point on the

page_text: hook and having its throat inclined from front to back, a conical shaped front for
the hook and a bobbin or thread case adapted to be supported within the hook the
inclined throat being so situated with respect to the thread case that as the hook
rotates carrying the loop, the part of the thread within or inside the hook is
thrown towards the back of the thread case, and that the part of the thread
outside the book is thrown on to the cone part and so over the front substantially
as set forth.
3. In a lock stitch sewing machine a hook, adapted to be rotated and provided
internally with a central groove and made in two parts and. having its front conical
shaped, a thread case having an external flange with opening at top and adapted
to work within the groove of the hook, a point on the hook having its throat
inclined so that the inner part is at the back of flange of the thread case and its
outer part to the front of the back edge of the conical part of the hook substantially
as set forth.
4. In a lock stitch sewing machine, a hook, a hollow shaft on which the hook is
mounted, a countershaft mounted eccentrically to and adapted to drive the hollow
shaft and be driven from the main shaft, a stop shaft bearing within the hollow
shaft and adapted to bear against an internal circular flange on the countershaft, a
bobbin or thread case mounted within the hook and adapted to be maintained
stationary by the stop shaft, substantially as set forth.
5. In a lock stitch sewing machine a rotary book consisting of a main body and
of a front part and point adapted to be secured to the main body, substantially as
set forth.
6. In a sewing machine, the mechanism for driving the feed consisting of an
arm secured to the feed plate, of a roller on which one end of the arm bears, of a
spring causing the arm to bear on the roller, of an arm carrying the roller, of a
cain on the countershaft for raising and lowering the arm at the required times, of
a countershaft driven from the main shaft and of an arm mounted on the counter-
shaft and pivoted to the other end of the feed arm substantially as set forth.
Dated this 3rd day of July 1894.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.