Year: 1886

page_text: I, ALEXANDER ANDERSON, Manager of The Singer Manufacturing Company's
Works, Kilbowie, Dumbartonshire, do hereby declare the nature of this invention,
and in what manner the same is to be performed (as communicated to me from
abroad by The Singer Manufacturing Company of New York in the United States
of America, Sewing Machine Manufacturers,) to be particularly described and ascer-
tained in and by the following statement :—
The object of this invention is to provide a simple and compact sewing machine
capable of running at a very high speed; and in addition to novel combinations
of parts constituting the main operative mechanism of the machine the invention
comprises a simple and effective cutting mechanism adapted to trim off the surplus
material parallel with and adjacent to the seam simultaneously with the sewing,,
and an improved thread comptrolling mechanism which is particularly adapted to a
rotary hook or looper chain stitch sewing machine.
--
In order that the invention may be fully understood I will now describe the
same in connection with the accompanying drawings in which fig. 1, is a side
elevation of a machine embodying my invention. Fig. 2, is a front end view of
the same. Fig. 3 is a sectional elevation, on line 3 3 fig. 4 looking in.the.
direction indicated by the arrows adjacent to said line, and fig. 4, is a plan view of
the lower part of the machine with the work plate removed and the frame in
section. Fig. 5, is a detail view of the feed bar and fig. 6, is a detail cross-section
of the feed bar and rockshaft-arm on line 6-6 fig. 4. Fig. 7, is a detail elevation
of the cutting devices, and fig. 8 is a similar view illustrating a modified form of
the same. Fig. 9, is a detail perspective view of one form of my cutting knife,
and figs. 10, 11, 12 and 13, illustrate, by enlarged diagrams, the cutting ends of
several forms of knives. Fig. 14, is a rear end view partly in section on line
14 14, fig. 1. Fig. 15 is a detail section on line 15- fig. 1. Fig. 16, is a
plan view showing the intermittent and check tensions. Fig. 17, is a detail view.
of the automatic check tension spring.
==
A, denotes the frame of the machine, said frame being compact as shown and
preferably cast in one piece. B, is the work plate, secured to the frame, and C, is

page_text: .
the driving shaft, journalled in the lower part of the frame and having thereon
a fly and pulley wheel D, provided with a crank-pin d connected by a pitman d¹,
with the rear arm e, of a rock shaft E, pivotted by centre screws e², to the upper
part of the frame A. The shaft E, is provided at its forward end with an arm e¹,
on the side of said shaft opposite to the arm e, so that said shaft will be evenly
balanced, the said arm e¹, being connected by a link e³, to a block f, attached to the
needle bar F.
The arms of the rock-shaft E, are preferably formed integral therewith and the
said shaft is of lesser length than the distance between the inner sides of the end
walls of the frame A, so that said shaft, with its integral arms, may be readily
placed in its working position, in assembling the parts of the machine. To give
steadiness to the shaft E, the frame A, is provided with thickened portions through
which the centre screws e², pass.
Secured to the driving shaft C is an eccentric c surrounded by a strap or yoke c¹,
said yoke having vertical and horizontal arms c² and c³, respectively. G, is a rock
shaft pivotted by centre-screws to standards a, on the frame A, said shaft having
an arm g, jointed to the vertical arm c², of the eccentric yoke c¹, and a second'
arm g, which is grooved (see fig. 6) to receive the feed bar H, provided with the
feed dog h. To the arm g', is attached a small hook or cap g², extending across
the feed bar H, and serving to hold the latter in the groove of the said arm so
that the downward movements of the latter will be imparted positively to
said bar.
Between depending lugs on the arms g, and g¹ of the rock shaft G, is pivotted
a feed rocker I, having an arm i, connected by a link or pitman to the horizontal
arm c³ of the yoke c¹, said rocker having a second arm provided with a pin or
yoke, which is engaged by a hook or slot h¹ on the feed bar H. The rocker I,
is preferably pivotted on a small rod is, passing through the arms g and g¹ of the
rock shaft and centrally through the said rocker. Thus as the arm i¹ vibrates
horizontally its movements will be imparted to the feed bar to give horizontal or
feeding movements to the latter.
To provide means for regulating the horizontal movements of the feed bar the
pin is carried by a yoke i, vertically adjustable on the arm i³, and secured in
any desired position by the thumb screw i³, passing through the pin or yoke
and impinging against the arm ². By moving the pin and yoke upward or away
from the rocker I, the horizontal throw of the feed bar will be increased, and by
moving said pin and yoke in the opposite direction the throw of the feed bar will
be lessened as will be obvious. L, is an ordinary Wilcox and Gibbs rotary hook
or looper co-operating with the needle to form chain stitches.
The operation of the machine will be readily understood from the foregoing.
Motion being imparted to the driving shaft, the needle-bar rockshaft E, connected
therewith will impart vertical movements to the needle-bar, and the needle carried
by the latter, with the co-operating rotary hook L, will form chain-stitches in the
usual manner. As the driving shaft C, rotates, the eccentric c thereon will impart
a circular movement to the yoke c³, the vertical movements of said yoke being
imparted to the arm g of the rock-shaft G, and through the latter to the arm g',
which carries, the feed-bar H. Thus the feed bar will be positively raised and
lowered, and between each up and down movement the said bar will be caused to
slide horizontally in its grooved carrying arm g¹, by reason of the vibrating move.
ments of the feed rocker i with which said bar is connected, as above described.
A's the feed rocker I, is connected to the horizontal arm c³ of the yoke c¹, which is at
a right angle, or nearly so, to the part of said yoke to which the arm g, of the rock
shaft G, is jointed, it results that the said rocker is nearly stationary during the
intervals when the said yoke is operating the rock shaft G, to impart vertical
movement to the feed bar, so that horizontal movement of the latter is nearly
suspended momentarily; and likewise the rock shaft G is nearly stationary
(causing the vertical movement of the feed-bar to be nearly suspended) during
the intervals when the feed' rocker is vibrating to move the said feed-bar hori-

page_text: zontally. It will thus be apparent that by the above described connections of the
feed-bar with the eccentric c, I am enabled to impart positive "four motioned'
movements to the latter in all directions, and to regulate these movements as may
be desired.
By virtue of the compact arrangement of the parts herein shewn, the evenly
balanced needle-bar operating rock-shaft and the positive feeding mechanism the
machine is adapted for very high rates of speed, having been tested to sew at a
speed exceeding four thousand stitches per minute.
In connection with the feeding mechanism of the machine I prefer to use a
trimming mechanism actuated from the feed-operating eccentric.
To this end I provide a cutting knife carried by a reciprocating head operated
by the eccentric on the driving shaft and working against a metallic cutting bed
or block which rests on a solid standard preferably formed integral with the frame
of the machine. I deem it advisable to grind and adjust the cutting knife so that
while the rear portion of its edge will be a trifle blunt and will, in operation,
positively strike the cutting block, the front portion of said edge (when the knife
is at the lowest limit of its stroke) but lightly touching said block. When ground
and adjusted in this manner the brunt of the downward thrust of the knife against
the cutting-block will be sustained by the blunt rear portion of its edge and the
forward or working portion of said edge will remain sharp except as it becomes
blunted by cutting the goods. Or instead of utilizing the rear portion of the edge
of the knife to take the downward thrust of the knife-carrier, at the terminations
of the downstrokes of the latter, a separate device, either moving with the knife
or stationary with the work-plate, may be employed for this purpose.
The eccentric yoke c¹ which operates the feeding mechanism is connected with
the pivotted arm g, provided with a head M, carrying the cutting knife N, secured
between the fixed or main portion of said head and a removable portion m thereof,
the latter being clamped by its attaching screws m¹, against the knife, and thus
serving to hold the latter firmly in place.
Tapped in a projection m², of the head M, is a screw O, by which, when the
screws m², are slightly loosened, the knife N, may be accurately adjusted. The
projection m³ is split (see fig. 3.) so that it may be compressed by a clamping set
screw m³ and thus securely retain the screw O, in any position to which it may be
adjusted.
The frame A, is provided with an integral post or standard a¹, on the top of
which rests the cutting bed or plate P, projecting slightly above the work plate B,
and provided on its underside with a flange recessed into the work-plate as shown
in fig: 1, so as to be held firmly in place on the standard or post a¹. The plate P,.
is preferably made circular so that it may be turned to bring different parts thereof
beneath the knife N, said plate being of metal or similar hard material. The
knife N is preferably made with the rear portion of its edge more or less blunt, as
indicated by the enlarged diagrams, figs. 11 and 12. This blunt portion n of the
knife serves as a striker to take the most of the thrust of the knife against the
cutting block, the knife being so ground and adjusted that the sharp or forward
part of the cutting edge will but barely or lightly touch the cutting bed or
plate.
Instead of making the striker n integral with the knife it may be made separate
therefrom (see fig. 13) and be secured to the knife-carrying head M, so as to move
with the knife as show in fig. 8; or it may be merely a small pin or post as n³,
(indicated by dotted lines in fig. 1) stationary with the work-plate or cutting bed
and arranged in the line of movement of some part of the knife-carrying head M
so that the latter, at the end of its down stroke, will impinge against it and thus
prevent the force of its thrust from being transmitted to the cutting bed through
the knife.
'
From the foregoing it will be apparent that when the driving shaft C, is rotated,
the eccentric c¹ thereon will cause the arm g, to vibrate, thus moving the head M
and the knife N, carried thereby up and down, and the said knife operating against

page_text: the cutting bed, as above explained, will trim off the edges of the goods parallel
'with the seam or line of stitches, and as the trimming knife receives its movements
from the feed-operating" eccentric and is caused to descend simultaneously with
the feed bar it follows that the trimming will be effected between the feeding
.movements of the feed bar.
In connection with the Wilcox and Gibbs rotary hook or looper L which
co-operates with the needle to form chain stitches, I provide an automatic or
intermittent tension, which is adapted to be operated by the needle-bar rock-shaft,
and between this intermittent tension and the spool from which the thread is drawn
I place a light check tension which exerts a slight but constant drag on the thread
so as to hold the latter properly when it is released by the intermittent tension.
In connection with the tensions aboverreferred to I prefer to use an intermittent
check tension, near the needle to exert a slight drag on the thread during the time
the needle is out of the work so that the thread will be held clear of the point of
the needle when the latter descends to pierce the work.
Sustained by the bracket r, is a check tension R, consisting in the present
instance, of a pair of ordinary tension discs held in contact by a light coil spring
surrounding the pin which supports the discs, the stress of said spring, to adjust
the tension, being regulated by a thumb-nut on said pin in the usual manner.
tension. R, is preferably placed above or in line with the spool link pin Q, as
shown in fig. 1.
The
To the top of the frame A, near the rear end thereof, is attached the automatic
or intermittent tension consisting of a block S, an elbow or bell crank lever T,
pivotted to said block and a coil spring t, the latter being placed in a bored-out
recess in said block, so as to press outward against the longer arm of said lever,
thus serving to hold the shorter arm of the latter in contact with the top of the
block. The end of the short arm of the lever T, extends slightly beyond the block
and the latter is provided with small projections s¹, one on each side of said arm,
said projections having open or slotted eyes or thread-holes. The lower end of
the long arm of the lever T, is curved, and is arranged adjacent to the arm e, of the
rock shaft E, so that said arm, in its vibrations, will impinge against said end at
intervals and will thus move said lever in opposition to the stress of the springt,
to lift the short arm of the lever from its bearing surface at the top of the block S,
to release the thread. To thread the tension the thread is drawn into the hole in
one of the projections 81, around and beneath the end of the short arm of the
lever T, and then into the hole in the other of said projections.
In fig. 15, the arm e of the rock shaft E, is shown as being just in contact with
the curved end of the long arm of the lever T, so that a further movement of said
arm in the direction indicated by the arrow adjacent thereto in said figure will lift
the short arm of said lever from the top of the block S, and release the thread.
This action occurs just after the hook L, has caught the loop of the needle thread
and the needle-bar is rising to tighten the last stitch, and thus the intermittent
tension will hold the thread during the greater part of the time that the needle-bar
is descending and while it is rising to throw out a loop for the hook, and will then
.release it to permit the needle-bar and rotary hook to draw sufficient thread from
the spool or sourse of supply, for the next stitch.
Attached to the inside of the face-plate a² of the frame A, is a light check tension
spring U, which extends outward through an opening in said plate and then
downward so that its lower end will bear against the outer side of said plate. Said
end is normally held in contact with the outer side of said plate by the stress of
the main portion of the said spring, and is lifted or pushed away therefrom at
intervals by the contact of the block or collar f, on the needle-bar with the inclined
lower portion of said spring inside of the face-plate a¹. The spring U, is provided
at the outer end of its bend with an open hole u into which the thread can be
drawn to bring it beneath the bearing surface at the lower end of said spring.
The thread passes from the spool (indicated by dotted lines in fig. 1,) or other
source of supply, through the light check tension R, to the intermittent or auto-

page_text: matic tension, and thence through a guide-eye V, to a hole in the top of the
needle bar F, (which serves as a take-up) passing from the latter downward
beneath the bearing surface of the automatic check tension U, to the needle. The
latter tension, exerts a slight friction on the thread as the needle descends until the
point thereof reaches the work when the block or collar f, impinges against the
spring U, and lifts the lower end thereof from the face-plate, as above described, to
release the thread which remains unaffected by this tension until the needle in its
ascent has nearly or wholly cleared the work.
By arranging the tension devices in the manner above described, to wit, with
the constant check tension between the main automatic or intermittent tension and
the spool, or other source of supply of the thread, and the intermittent check
tension between the main intermittent tension and the needle, I am enabled to
control the thread with a nicety and exactness which I deem to be impossible with
any other arrangements of these devices.
Owing to the delicate and accurate manner in which the thread is controlled by
the devices above described they largely contribute towards rendering the machine
capable of very high rates of speed for which it is more particularly intended.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me, I declare that what I claim is :-
1. In a sewing machine the combination with a driving shaft, carrying an
eccentric, of a yoke surrounding the latter, a rock shaft having two arms one of
which is connected with said. yoke, a feed bar supported by and adapted to slide
on the other of said arms, a feed rocker supported by the arms of said rock-shaft
and connected with said feed-bar, and a link jointed to an arm of said feed-rocker
and to the said yoke, substantially as set forth.
2. In a sewing machine the combination with a driving shaft, provided with an
eccentric, of a yoke surrounding the latter, a rock shaft and a feed-rocker having
connections with said yoke said connections being at a right angle, or approxi-
mately so, to each other, and a feed-bar connected with said rocker and adapted to
slide on an arm of the said rock-shaft, substantially as set forth.
3. In a sewing machine the combination with a driving shaft, provided with an
eccentric, of a yoke surrounding the latter, a rockshaft having two arms one of
which is connected with said yoke and the other of which is grooved, a feed-bar
adapted to slide in the latter arm and provided with a hook or slot, a feed rocker
having two arms, a link connecting one of said arms to the said yoke, and an
adjustable pin or yoke, carried by the other of said arms and engaged by the said
hook on the feed-bar, substantially as set forth.
4. In a sewing machine the combination with a feeding mechanism and a
trimming mechanism of a single eccentric serving to operate both of said
mechanisms and a shaft by which said eccentric is carried, substantially as
set forth.
5. In a sewing machine, the combination with the stitch forming mechanism, of
a flat plate or bed of hard material adjacent thereto, a straight-edged trimming
knife above said plate or bed having its edge parallel with the line of feed,
mechanism for reciprocating said knife to cause it to cut or trim the material being
sewed, and a striker for softening the thrust of said knife against the surface of
the said plate or bed, substantially as set forth.
6. In a sewing machine, the combination with the stitch-forming mechanism, of
a flat plate or bed of hard material adjacent thereto, a straight-edged trimming
knife arranged to cut against said plate or bed and having its edge parallel with
the line of feed, mechanism for reciprocating said knife to cause it to trim the
material being sewed, and a striker, movable with said knife, for softening the
thrust of the latter against the said plate or bed, substantially as set forth.
7. The combination with the frame of a sewing machine having a post, as a,
integral therewith, of a cutting plate or bed secured against the top of said post

page_text: and having a flat upper surface, and a reciprocating trimming knife adjusted to
cut against the said surface, substantially as set forth.
8. In a sewing machine, the combination with the stitch-forming mechanism, of
a shaft having an eccentric thereon, a flat plate or bed of hard material adjacent
to said mechanism, a vibrating arm connected with said eccentric and having a
knife-carrying head or portion, a knife adapted to cut against the upper surface of
the said plate or bed and having its edge parallel with the line of feed, and a
striker for softening the thrust of the said knife against said plate or. bed, substan-
tially as set forth.
9. The combination with the stitch-forming mechanism of a sewing machine, of
a reciprocating knife-carrying head having a split projection, a knife longitudinally
adjustable in said head, an adjusting screw tapped in said projection, and a
clamping or set screw for compressing the jaws or parts of said projection against
said adjusting screw, substantially as set forth.
10. The combination with the frame A, having the supporting post a, of the
flanged cutting plate or bed and the recessed work-plate by which the said cutting
plate.is secured to the top of said post, substantially as set forth.
11. In a sewing machine the combination with an automatic or intermittent
tension, of a constant check-tension placed between the intermittent tension and
the spool or other source of supply of the thread, and an intermittent check tension
between the former intermittent tension and the needle, substantially as set forth.
12. In a sewing machine, a bracket-arm or frame, a block secured thereto, a
rockshaft having an arm, a bell-crank tension lever pivotted to said block, one arm
of said lever being arranged in the path of said rockshaft arm, combined with a
spring for pressing the other arm of said tension lever against a bearing surface
afforded by the said block, whereby said tension lever is adapted to clamp and
release the thread alternately, substantially as set forth.
13. The combination with a rock-shaft, and its arm of the block S having
projections s with thread holes, the lever T pivotted to said block and the spring t,
substantially as set forth.
14. In a sewing machine the combination with the face plate, having an opening,
of a bent tension spring attached to the inside of said plate and extending outward
so that its lower end will bear against the outer side of said plate, and a device
reciprocating with the needle-bar and adapted to engage said spring at intervals,
substantially as set forth.
15. In a sewing machine the combination with the face-plate, the needle-bar and
operating mechanism for the latter comprising the collar or block f, of the inclined
and bent tension-spring U, attached to the inside of said face-plate but having a
bearing surface outside of the latter substantially as set forth.
Dated this second day of September 1886.