Improvements in or relating to Sewing Machines.
Year: 1894

page_text: Date of Application, 8th Dec., 1894
Complete Specification Left, 2nd Sept., 1895--Accepted, 30th Nov., 1895
TRUVIDIONAL DE MULLICATION.
Improvements in or relating to Sewing Machines.
I, DANIEL JONES of Argyle Street Nechells Birmingham in the County of
Warwick Engineer do hereby declare the nature of this invention to be as follows,
that is to say :-
This invention has for object improvements in sewing machines which have an
upper and a lower shaft caused to revolve in a given relation the one to the other
by means of a connection lever which oscillates about a fulcrum situated between
the two shafts, and comprises means for obtaining a variable relative rotary
movement in both of the said shafts, and for imparting approximately vertical and
horizontal movements to the feed bar or cloth moving mechanism from the motion
of the said connection lever about the said fulcrum.
Hitherto it has been customary to cause one of the said shafts to revolve at a
regular speed throughout a revolution, whilst the other was caused to move at an
irregular speed during a revolution to allow loops of thread to be taken from the
needle and cast off at proper times.
I find that at high speeds the irregular rate of revolution if confined to one shaft
sets up violent vibrations which practically limit the speed of the machine and the
size and weight of the moving parts on or connected to the said shaft. To reduce
this vibration I have devised means whereby the required variable movement is
divided between the upper and lower shafts.
Hitherto the feed bar has usually been operated by a cam or cams, generally of
the four motion variety, with two periods of rest and two periods of motion in a
revolution. These cams at high speeds produce blows which cause noise and
vibration.
I dispense entirely with cams for this purpose and derive an approximate four
motion movement of the feed bar from the aforesaid connection lever.
Hence my improved machine may be run at high speed without excessive noise
or vibration.
The upper and lower shafts I mount on the arm and bed plate respectively.
Both shafts extend from the front part of the machine towards the rear; but
neither of them extends to the rear of the vertical part of the hollow arm. Upon
their rear ends I fix a crank or disc formed with a slot to allow the drive pins, or
rollers or blocks thereon, to approach and recede from the axis of the respective
shafts. A connection lever oscillating and sliding upon a fulcrum suitably placed
between the two shafts carries pins at its upper and lower ends, which pins engage
with the said discs respectively. At the upper end of the connection lever and on
its rear side is placed another pin the axis of which does not coincide with the
axis of the pin that engages the disc of the aforesaid upper shaft. A short driving
shaft carried in a bearing coaxial with the said upper shaft, which bearing is
carried by the aforesaid hollow arm, is also provided with a disc or crank having a
hole to receive the pin on the rear side of the connection lever.
When the driving
shaft is rotated the rear top pin of the connection lever is caused to move in a
circular path concentric with the driving shaft. The front top pin of the con-
nection lever will also be caused to move in an approximately circular path which
will not be concentric with the upper shaft. Consequently a varying velocity will
be imparted to that shaft.

page_text: The front lower pin of the connection lever will move in an oval path, owing to
the motion of the said lever upon its fulcrum, and thus the lower shaft will also
have varying velocity imparted to it.
Thus the required total variation of velocity is divided between the upper and
lower shafts.
Instead of slot discs or slot cranks; drag links piston slides, or other equivalent
devices may be used.
The oscillation and sliding of the said connection lever on its fulcrum I use to
actuate the cloth feed mechanism as follows:-I use a feed bar carried upon way
shafts parallel with the lower shaft in such way that a rocking motion conveyed
to the way shafts operates the feed bar.
To the rear end of the shaft which effects the horizontal movements of the
feed bar I fix a lever connected to the lower part of the aforesaid connection lever
by means of a series of links one of which acts as a radius rod, being connected at
When
one end to a fulcrum attached by a movable arm to the machine frame.
the said fulcrum is placed coaxial with the pin by which the first of the series of
links is connected to the lever on the way shaft, the motion of the connection
lever causes no rocking of the said shaft. But if the fulcrum is placed in any
position not coaxial with the said pin the said shaft will be rocked to an extent
dependant upon the distance of the axial line of the fulcrum from the axial line of
the pin. When the fulcrum is, above the pin the horizontal movement of the
cloth feed bar will be in the opposite direction to that which would occur if the
fulcrum were below the pin.
To the rear end of the way shaft which effects the vertical movement of the
said feed bar I also fix a lever. A lever is also fixed to a block placed upon the
fulcrum about which the connection lever moves. The said lever oscillates and
reciprocates upon that block and communicates a rocking motion to it and to the
arm fixed to it. A link connects this arm to that fixed on the way shaft for the
vertical movements of the feed bar, and thus a rocking motion is imparted to that
way shaft. The rocking motion thus imparted is greatest when the driving pin at
the top end of the connecting rod crosses the vertical centre line of the upper
shaft, and is least when that pin crosses the horizontal centre line of that shaft,
so there is practically no rocking of the said way shaft at those times.
The sliding movement of the connection lever upon its fulcrum is greatest when
its top end is crossing the aforesaid horizontal centre line of the upper shaft, and
least when crossing the said vertical centre line. The connection lever thus com-
municates the greatest rocking motion through the series of links to the other
way shaft at those times when the said lever communicates the least rocking motion
through the fulcrum block arm and link to the way shaft thus operated.
The result of the combination of parts described is an approximation to the
four motion feed usually produced by cams, and is free from the shocks and
vibrations which cams give rise to.
Dated the Eighth day of December 1894.
Improvements in or relating to Sewing Machines.
I DANIEL JONES of 62 Albion Street Birmingham, in the County of Warwick,
Engineer 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, that is to say :-
This invention has for object improvements in sewing machines having an

page_text: upper and a lower shaft caused to revolve in a given relation the one to the other
by means of a connection lever oscillating about a fulcrum situated between the
said shafts, and comprises means for obtaining a variable relative rotary movement
of the said shafts, and for imparting vertical and horizontal movements to the feed
bar or cloth moving mechanism from the movement of the said connection lever
about its fulcrum.
Hitherto in these machines it has been usual to cause one of the said shafts to
revolve at a constant angular velocity throughout a revolution: the other shaft
being caused to move more slowly and then more quickly than the first, so that
both shafts make a complete revolution in the same time. This varying speed is
required to allow loops of thread to be taken from the needle and cast off at
proper times.
I have found by experiment that at high speeds the variable movement shaft is
subject to violent vibrations which practically limit the speed of the machine and
the size and weight of the parts to be attached to the said shaft, and in order to
reduce this vibration I have devised mechanism whereby the variable movement
required is divided between the upper and lower shafts.
In sewing machines as heretofore constructed the feed bar is usually operated
by a cam or cams fixed on one of the aforesaid shafts. These cams are generally
of the four motion variety; giving two periods of rest and two periods of motion
during a revolution. Such cams at high speeds produce blows causing noise and
vibration. In this invention I dispense with the use of cams and derive an
approximate four throw motion from the aforesaid connection lever.
One method of carrying my invention into effect is described in this Specification
and in the accompanying drawings in which :-
Fig. 1 is a longitudinal vertical section of the rear end of a sewing machine.
Fig. 2 is a partial transverse vertical section of the same from the rear.
Fig. 3 is a plan of the mechanism by which the cloth feed is operated from the
connection lever.
Fig. 4 is a transverse vertical diagram showing the relative positions of the
driving cranks and pins, connection lever, and feed motion mechanism.
The upper shaft c, and lower shaft d, are mounted in bearings carried by the
arm a, or bed-plate b, respectively in the usual way. Neither shaft extends to
the rear of the hollow arm a, or other support of the upper shaft bearings.
Upon the rear ends of c, and d, I fix respectively the crank or disc c¹, d¹. These
are each formed with a slot c², d, respectively to allow the drive pins, roller or
slide block c, d respectively, to approach and recede from the axis of their
respective shafts. The said shafts are connected by means of the connection
lever e, having pins e¹, e², at its upper and lower ends which engage with ca, d³,
respectively in the slots of the upper and lower cranks or discs. The lever e,
reciprocates and vibrates about the fulcrum f, placed at a suitable point between
the two shafts. At the upper end of the connection lever a second pin or stud g, is
fixed. The axis of g, does not coincide with the axis of e¹. In rear of the con-
nection lever is another crank or disc h, fixed upon a short driving shaft j, carried
in a bearing k, and having its axis in line with that of shaft c. The disc or
crank, has a hole or bearing to receive the above mentioned stud g, which is at
the top end of the connection lever.
When the shaft j, is rotated the stud 9, is caused to move in a circular path of
constant radius to the axis of shaft j. The pin e', is also caused to move in a path
which is approximately circular but which is eccentric to the axis of the shaft c.
Thus the distance of pin e', and slide block c², from the axis of shaft c, varies
during a revolution, and a varying angular velocity is imparted to c, in respect of
each revolution of shaft j.
The pin e, at the lower end of connection lever e, moves in an oval path
determined by the vibration and reciprocation of lever e, upon fulcrum f. Hence
the lower shaft, being driven by pin e², acting on slide block d³, which slides in
slot d, of the crank or disc d', is also moved with a varying angular velocity. By

page_text: these means the required total variation of velocity is divided between the upper
and lower shafts.
Instead of slot cranks any equivalent mechanical device may be used, but the
mechanism described is what I find the best.
To actuate a feed bar carried by levers on shafts m, n, caused to rock inter-
mittently, the one imparting horizontal motion to the feed bar and the other
imparting vertical motion, I employ the vibrating and reciprocating action of the
connection lever e. To effect the horizontal motion of the feed bar I fix a lever m',
at the rear of shaft m, and connect it to the connection lever e, at e³, by the
links m², m³, of a series of links, of which series me is a radius rod connected at one
end to m², and at the other to the arm m, hung upon pin m³, carried by the frame
of the machine. By varying the position of the arm m, the fulcrum for the radius
rod or link me may be brought to a position co-axial with the pin connecting
link m², to lever m³, of the shaft m. In this position the links m², m³, convey no
motion from the lever e, to the lever m', and no rocking motion is produced in the
shaft m.
When the fulcrum for the radius rod mo, is fixed in any position not
co-axial with the pin connecting link m², to lever m², the shaft m, will be rocked to
an extent dependent upon the distance of the axial line of the said fulcrum from
the axial line of the said pin. A lever m', is fixed upon the pin m³, and has a
binding screw m³, and quadrant m³, for fixing the said fulcrum of radius rod m³, in
any desired position. When the fulcrum of radius rod m³, is above the link m² the
upward pull of pin e³, and link m³, upon link m², pulls the arm m', towards the con-
nection lever e; but when the said fulcrum is below the link m², the upward pull
of pin e³, and link m³, upon link m², forces m³, away from the said connection lever.
Hence when the said fulcrum is above the link m2, the cloth feed will be in the
opposite direction to that which occurs when the said fulcrum is below the link m².
The said quadrant may be marked with lines indicating the amount of cloth feed
co-incident with various positions of the fulcrum.
Upon the way shaft n, by which a vertical movement is communicated to the
feed bar, an arm or lever n', is fixed. An arm or lever n³, is fixed to the fulcrum
block n of the fulcrum f. The connection lever e, reciprocates and oscillates
upon n, and communicates to it a rocking motion. The arm n', of the way
shaft n, is connected with the arm n³, of the fulcrum block n³, by the link or bar n*,
shaft n.
way
The
and the rocking motion of block n², is thus communicated to the
fulcrum block n³, and its arm n³, will rock or swing from side to side most quickly
when the upper end of lever e, is crossing the vertical centre line upon which
shafts j, c, and d, lie; but when the top end of lever e, is crossing the horizontal
centre line of shafts j, and c, there will be practically no vibration or rocking of
lever fulcrum block n², or shaft n. On the other hand the end wise movement
of lever e,
is greatest when its top end is crossing the aforesaid horizontal centre
line of shafts j, and c, and least when its top end is crossing their vertical centre
line. Lever e, thus communicates through e³, and the links m², m³, the greatest
rocking motion to shaft m, at those times when the fulcrum block n², communicates
through arm n³, and link n', the least rocking motion to shaft n.
e,
It will be readily understood by those conversant with sewing machines of this
class, that a four motion feed bar, carried upon arms fixed to the front ends of the
shafts m, and n, (not shown in the drawings) and at suitable angles to the
arms m³, n¹, respectively, will be consecutively moved vertically upwards, horizon-
tally in one direction, vertically downwards, and horizontally in the opposite
direction, in a way which will closely approximate to the similar consecutive motions
given by a four motion cam acting upon the said shafts m, and n, alternatively; and
that the consecutive motions produced by the improved methods described in this
Specification will be free from the shock caused by a cam moving at a high speed,
and that this cause of vibrations in the said shafts m, and n, will be avoided.
The diagram Fig. 4, shows by the circle a¹. . ., the path of pin g. The path of
pin el, is shown by the curve y.. .y¹.
The angles contained by the lines cy', cy²; cy², cy³; cy³, cy; cy, cy¹; as compared

page_text: respectively with the angles contained by the arcs x²x², x²x³, x³ x¹, x² x¹ ; show
the variations in the angular velocity of shaft c, as compared with each quarter-
revolution of the coaxial driving shaft j. The path of pin e, is shown by the
oval z¹.... The path of pin e³, is shown by the curve v...vt. The position
of the links m², m³, &c. when the fulcrum of m³, is coaxial with the pin connecting
link m², to arm m¹, of shaft m, is shown by thick lines when lever e, is at bottom of
its stroke, and by thick dotted lines when lever e, is at the top of its stroke. The
position of m², m³, &c., when the fulcrum of me, is at its lowest position, is shown
by thin lines when lever e, is at bottom of its stroke, and by thin dotted lines when
lever e, is at the top of its stroke. The position of m³, m³, &c., when the fulcrum
of me, is at its highest position, is shown by dot and dash thick lines when the
lever is at the bottom of its stroke; and by dot and dash thin lines when lever e,
is at the top of its stroke.
e,
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. In a sewing machine, a connection lever, fulcrum, and parts, which impart
varying angular velocity of rotation to both the upper and the lower shafts; while
they also impart vertical and horizontal movements alternately to the cloth feeder,
substantially as described.
2. In a sewing machine, a lever working upon a fulcrum and carrying two studs,
by means of which a rotating driving shaft rotates a driven shaft at a varying
angular velocity during each revolution of the said shafts, substantially as
described.
3. In a sewing machine, an upper and lower shaft connection lever and fulcrum,
in combination with a series of links and a radius rod and fulcrum, by means of
which combination the vertical movement of the said lever is caused to operate the
feed bar horizontally and to a variable extent, substantially as described.
4. In a sewing machine, an upper and lower shaft connection lever in combination
with a fulcrum on which the said lever oscillates, a fulcrum block to allow the said
lever to move end wise over its fulcrum, an arm to the said fulcrum block, and a
link or links, by means of which combination the oscillating motion of the said
lever is caused to operate the feed bar vertically, substantially as described.
Dated this Second day of September 1895.
THOS. WILKINS,
Agent for the Applicant.