Improvements in Sewing Machines.
Year: 1893

page_text: COMPLETE 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 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 sewing machines
in which a rotary shuttle carrying a ball of twine or cotton is employed.
In a machine constructed according to this invention the thread case is formed in
two halves adapted to be closed together and to contain a ball of twine without reel
or other support. The thread case is loosely suspended in the rotary shuttle by a
rounded projection within the shuttle and by a ball loosely carried in a latch lever
so that the loop of the stitch readily passes between the thread case and the latch
lever that holds the thread case stationary in the shuttle as the loop is carried
round to enclose the locking thread by the shuttle. The shuttle is supported in a
circular shuttle race consisting of two adjustable bearing pieces secured to a fixed
bracket so that the centre of rotation of the rotary shuttle can be adjusted laterally
and any wear taken up. The shuttle is driven by means of two concentric rotating
drivers rotated by rotating studs set eccentrically to the rotating drivers so as to
obtain a slow motion as the hook takes the thread from the needle one stud being
arranged in advance of the other so that the driving is taken up alternately by the
two drivers to allow the thread to pass the drivers. The feed plate is circular and
is supported and rotates on a sheave or ring secured to the frame of the machine at
one side by a pivotted joint and at the other by an adjustable fastening so that it
can be drawn up towards the cloth plate to vary the extension of the feed plate
above the cloth plate. The feed plate is actuated by a nipping lever and back
motion of the plate is also prevented by a stationary nipping lever. The feed
nipping lever is actuated from an arm fixed on a shaft running underneath the cloth
plate from end to end and having at its other end an arm connected to one end of
a link sliding through a pivotted sleeve and having at its other end a roller working
in a race in a lever vibrated from an eccentric on the main shaft. The sleeve is
adapted to be moved to force the roller nearer to or further from the fulcrum of
the lever to adjust the extent of motion of the roller and thus the length of the
stitch.
In the accompanying five sheets of illustrative drawings :-
Figure 1 is a sectional elevation of a sewing machine constructed according to
this invention; and Figure 2 is a part central vertical section showing the shuttle
and its driving mechanism and Figure 3 is a part sectional front end elevation of
the same.
Figure 4 is a front sectional elevation showing the fixed shuttle bracket and the
shuttle drivers.
Figure 5 is a cross section through the shuttle driving mechanism showing the
parts in the positions they occupy when the shuttle hook is taking the loop from
the needle the shuttle being driven at its heel and Figure 6 is a front elevation of
the same.
Figures 7 and 8 are corresponding views to Figures 5 and 6 showing the shuttle
driven at its book after the loop has passed the hook.
Figures 9 and 10 are sectional back end elevations showing the feed mechanism
just after and just before a feed movement.
The rotary shuttle a rotates in the bearing pieces b supported by a ring b¹ secured
by screws to the bracket 62 depending from the cloth plate c. As shown the race
of the bearing pieces bis-shaped in cross section and a corresponding recess is

page_text: formed in the periphery of the rotary shuttle. The bearing pieces are secured
to the ring by means of screws 3 passing through elongated holes in the bearing
pieces so that the position of the centre of rotation of the rotary shuttle can be
adjusted laterally and that any wear between the bearing surfaces of the race and
shuttle can be readily taken up. The bearing pieces are adjusted by means of
the screws passing through the fixed ring b¹. The ring b¹ can also be adjusted
on the bracket 12.
The thread case d for the under thread is formed in two halves adapted to be
secured together by catches and to contain a ball of twine e without reel or other
support, the thread being drawn from the centre of the ball and passing through a
The thread case
hole d' in the top of the case through a suitable tension device.
is formed with two spherical recesses d' opposite to one another and by which it is
suspended centrally within the shuttle. The shuttle is provided at its centre with
a spherical projection d³ taking into the inner recess of the case d and a ball f¹
loosely carried in a latch lever f takes into the other recess d². The latch lever f
is pivotted to a projection secured to the ring b by a screw be. The upper end f
of the latch lever fis forked to engage the projection on the thread case d to
hold it stationary whilst the shuttle rotates. It will readily be seen that as the
shuttle hook carries the loop from the needle round to enclose the locking thread
the thread easily passes the lever f holding the thread case d stationary as the
ball is free to rotate on the passage of the thread. The ball f' is inserted from
the back of the lever and is retained in place by the spring 3. The latch lever f
is retained in the position shown by the latch controlled by the spring f³.
The shuttle a is driven by means of two drivers g g' fixed on concentric shafts h h¹
the shaft being mounted within the shaft and the shaft h' being mounted in a
bearing 2 depending from the cloth plate c. The shafts h h are driven from the
countershaft itself driven from the main shaft i as clearly shown. The axis of
the shafts his eccentric to that of the countershaft and the shaft h is driven by
means of the link j and arm 1 from the part m of a double eccentric stud fixed to a
disc on the end of the countershaft i¹ and the shaft is driven by means of the
link and arm from the part m' of the double eccentric stud, the part m¹ being
slightly in advance of the part m, so that the shuttle is driven alternately by the
two drivers 9 g' as will be presently described. The eccentricity of the shaft i¹
causes the drivers to be driven at a variable speed, so that when the hook is taking
the thread from the needle the speed is slow. As the part m' is in advance of the
part m of the eccentric stud the speed of the drivers is also variable in relation to
one another the driver g¹ acting on the heel of the shuttle driving the shuttle as
shown in Figure 6 whilst the hook is taking the thread and until the loop has
passed the driver g and the driver g acting on the hook of the shuttle taking up the
driving as shown in Figure 8 when the loop passes the driver g' acting on the heel
of the shuttle.
.
The feed plate n is circular and works on a sheave o fixed at one side to a shaft o'
The
supported by pivots o2 screwing into lugs c depending from the cloth plate c.
other side of the sheave o is pivotted to a screwed lug o³ on which screws a nut o*
itself screwing into the cloth plate c. The outer and inner threads of the nut of
are of different pitch or one is right and the other lefthanded so that by screwing or
unscrewing the nut of the height of the centre of the sheave o is adjusted and
The feed
consequently the amount the feed plate projects above the cloth plate c.
plate n is retained on the sheave by the flange o' of the sheave on one side and by
the spring of and headed screws o secured on the other side of the sheave and can be
removed therefrom by removing the spring of and screws o'.
The feed plate n is rotated after each stitch has been made by means of a nipping
lever p having a square recess fitting loosely on the boss n¹ of the feed plate. The
lever p is pivotted at its outer end to the link p' itself. pivotted to an arm p² on a
countershaft p³. A spring p¹ secured to the sheave o cets on the inner end of the
lever p and tends to force this end backwards that is in a direction opposite to the
motion of the feed plate. The sheave o is cut away at o8 to allow of the motion of

page_text: the nipping lever. It will readily be seen that if the nipping lever is moved
forwards by the link p' the lever p will be slightly twisted and will nip the boss n'
of the feed plate and force it forward to feed the plate as shown in Figure 3. On
the return of the link pl the spring p' at the same time forces back the inner end of
the lever p consequently it slides freely over the boss n¹. The backward motion
of the feed plate is prevented by a nipping lever r having a recess fitting loosely in
the boss and having its outer end bearing against the boss o' by which the
sheave is fixed to the shaft o¹. The lever is pulled in the backward direction
by the spring r¹. The sheave o is suitably cut away at o¹ to allow the lever r
to act.
The countershaft p³ is actuated from an eccentric s on the main shaft the
eccentric rods being jointed to one end of a lever 2 pivotted at to the main
frame of the machine. The other end of the lever s² is formed with a roller race
in which works a roller s mounted on one end of a link connected to an arm se on
the countershaft p³. A vibratory movement is thus given to the shaft p³ and
nipping lever. In order to vary the amount of this movement the link slides
freely in a sleeve s pivotted to the head of a screw 8 fitting in a nuts screwing
into the frame, the external and internal threads of the nuts are right and left
handed or of different pitch so that the sleeve s can be moved inwards or out-
wards to vary the distance of the roller from the fulcrum of the lever s² and
consequently the motion of the countershaft p³.
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 mechanism for driving the circular feed plate, consisting of a nipping
lever working on the boss of the feed plate, of links pivotted to the lever and
connected to an arm on a countershaft, of a countershaft, of a countershaft driven
from the main shaft and of a spring acting on the nipping lever, the whole
substantially as described.
2. The mechanism for varying the feed of the feed plate consisting of a counter-
shaft adapted to operate the feed mechanism, of a pivotted lever vibrated from the
main shaft, of a link connected at one end to the countershaft and connected at the
other end by a sliding joint to the vibrating lever and of a sleeve through which
the link is free to slide and which is adapted to be operated to move the sliding end
of the link nearer to or further from the fulcrum of the lever, the whole
substantially as described..
3. The construction and arrangement of a sewing machine substantially as
described with reference to the drawings.
Dated this 15th day of July 1893.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.