IMPROVEMENTS IN SEWING MACHINES
Year: 1870

page_text: LETTERS PATENT to Michael Heinrich Kernaul, of Berlin, in the
Kingdom of Prussia, for the Invention of "IMPROVEMENTS IN SEWING
MACHINES."
Sealed the 24th February 1871, and dated the 27th December 1870.
PROVISIONAL SPECIFICATION left by the said Michael Heinrich
Kernaul at the Office of the Commissioners of Patents, with his
Petition, on the 27th December 1870.
I, MICHAEL HEINRICH KERNAUL, of Berlin, in the Kingdom of
Prussia, do hereby declare the nature of the said Invention for "Iм-
PROVEMENTS IN SEWING MACHINES," to be as follows:-
My Invention has reference more particularly to that class of sewing
machines that work with a rotating hook, and which are generally known
as "Wheeler and Wilson Machines."
One part of the Invention has reference to the pulley and excentric
on the hook spindle and the connecting rod to the excentric. In place
of providing the pulley with a leather surface, as is at present donė, I
cover the metal surface of the pulley with "chequering," which effec-
tually prevents any slipping of the belt. The excentric, which is cast in

page_text: one with the pulley, is formed with a spherical periphery upon which
the excentric strap of the connecting rod fits with a corresponding
hollow spherical surface, thus forming with the excentric a spherical
joint which produces great evenness of motion. The connecting rod is
furthermore connected to the lever of the needle-arm spindle or "rocker"
by means of a taper steel pin, which passes into a correspondingly
tapered eye in the connecting rod, and screws into the one side of the
lever fork, outside of which a lock nut is screwed on to the pin. Any
back lash through wear of the connecting rod eye is prevented by
screwing the taper pin farther through the lever fork, which is effected
by turning the nut-shaped head of the pin projecting on the other side
of the fork by means of the same spanner that turns the screw of
the needle yoke, and which is also made to fit the before-mentioned
lock nut.
Another improvement has reference to the needle-arm spindle or
"rocker." This is formed with cylindrical ends passing through holes
in the uprights of the frame, but instead of taking a direct bearing in
these the spindle is extended beyond these, but of reduced diameter, and
upon these extensions are formed screw threads, upon which are screwed
conical or taper nuts fitting partially over the larger part of the spindle
and into the tapered outer ends of the holes in the uprights through
which the spindle passes, thus forming adjustable bearings, allowing
both of longitudinal adjustment of the spindle and of adjustment to
prevent any looseness in the bearings through wear. The screwed ends
of the spindle pass through the adjusting nuts, and are provided with
lock nuts, which are also capable of being turned by the spanner to the
needle yoke.
Another improvement has reference to the tension pulley to the upper
thread. The construction of this pulley as at present employed has the
objection that it requires to be oiled, whereby it occasionally becomes
clogged and dirty, thus preventing a uniform tension being maintained.
According to my Invention the two metal discs of the pulley are
screwed on to a boss of vulcanite which requires no oiling, against which
presses the end of a sleeve covering a spiral spring, which is acted upon
by a nut screwed on the pin carrying the pulley, so as to press the end
of the sleeve against the vulcanite boss. The nut has a pin or feather
sliding in a slit in the sleeve, so as to prevent any working loose of
the nut.

page_text: Another part of my Invention has for its object the application of a
tension to the lower thread, which is very desirable when the machine
is used for heavy work. For this purpose a finger is so arranged in
front of the spool between it and the slide ring as to press upon the
boss of the spool, and retard its rotation at such time during the revo-
lution of the rotating hook when the thread is drawn from the spool, at
which time the rotary hook will be free of the previously formed loop,
or sufficiently so as to allow of the contact of the finger with the spool.
When, on the other hand, the loop of the upper thread is passing over
the spool and rotating hook the pressing finger is moved away from the
spool so as to allow the loop to pass. For producing this action of the
pressing finger it is fixed to or formed in one with a rod projecting at
right angles therefrom, which rod passes through a cavity formed in the
standard carrying the front end of the hook spindle. In this cavity is a
spiral spring which presses against a collar on the rod in such manner
as to tend to draw the finger against the spool. The pressure of this
spring, and consequently the pressure of the finger on the spool, is
regulated by a screwed bush through which the rod passes, and which
is screwed into the front end of the before-mentioned cavity so as to bear
against the spring. The rod carries a pin or feather fitting into a notch
in the front end of the screwed bush, so that in turning the rod by
moving the finger to the right or to the left the screwed bush can be
turned so as to increase or decrease the pressure of the spring, and when
the finger has been moved through half a revolution the action may
be repeated by first drawing the finger with its rod forward so as to
draw the pin or feather out of the notch in the bush, whereupon
after turning the finger and rod back again through half a revolution,
and letting the pin pass again into the notch of the bush, the above
operation is repeated. The rod passes right through the standard,
and bears with its end surface against a rim or cam surface upon
the pulley of the hook spindle, which rim or cam surface is so formed
that during that part of the revolution of the hook when the presser
finger requires to be removed from the spool the rim or cam surface
presses the rod and with it the finger outwards against the action
of the spring, while during the remaining portion of the revolution
(when the thread is drawn from the spool) a recess or depression in
the rim or cam surface allows the spring to draw the finger against
the spool, and thus to effect the required tension of the lower thread
as before described.

page_text: Another improvement has reference to the mode of securing the slide
ring. In order to render its adjustment and removal more easy than at
present the bed plate of the machine has an under cut groove formed in
it, in which groove slides the head of a screw that passes loosely through
a hole in the flange of the slide ring; and upon the projecting end of
the screw is screwed a nut, by the screwing up of which the slide ring
is secured in position, while by slightly unscrewing the nut the head of
the screw will be loose in the groove of the bed plate, and will thus
allow the slide ring to be moved forward or backward or entirely with-
drawn. The screw is by preference formed with a left-handed screw
thread, so that for fixing the slide ring the nut may be turned in the
same direction as an ordinary screw.
Another part of my Invention has reference to an improved con-
struction of the "silent feed," whereby this is rendered more simple in
arrangement than the arrangements described in A. V. Newton's Patents,
Nos. 970 of 1867, and 960 of 1870, and whereby also a perfectly parallel
vertical motion of the "dog" or toothed or roughened surface is attained.
For this purpose the dog is formed as a rectangular block fitting in a
corresponding rectangular groove in the front standard. The hook
spindle carries two excentrics or cams, one behind the standard, and by
preference formed in one with the spindle pulley, while the other is in
front of the standard (which is recessed to receive it), and is fixed upon
the spindle. Both excentrics or cams have exactly the same throw, and
are in precisely the same relative positions, so that as the spindle revolves
the two excentrics raise the dog or sliding block in a perfectly parallel
manner so as to bring it into action. On the back surface of the dog or
sliding block is a flat short arm, which is pressed tightly against such
back surface by a screw upon which it is capable of turning. The arm
carries a stud which is acted upon by a cam surface on the spindle
pulley, so as to impart to the dog the requisite horizontal forward motion
when in the raised position, in a similar manner to the action of the
cam surface described in the Specification to Newton's before-mentioned
Patents. The arm is shifted, so as to bring the stud into position for
increasing or decreasing the length of stitch by means of a small lever
moved by the hand. To steady the dog or sliding block in its motion a
pin passes vertically through a hole formed in it, which pin is carried by
a plate beneath the dog sliding in under cut grooves in the standard.
The backward motion of the dog is effected by a spring arranged and

page_text: acting in a similar manner to that described in Newton's Specification,
No. 970 of 1867. If vertical adjustment is desired for the dog this may
be effected by dividing the block horizontally into two parts connected
together by two screws so arranged that the upper part may thereby be
raised away from the lower part...
Another part of my Invention has reference to the loop check brush.
The block or "segment" of the brush is secured in position by a screw
with left-handed screw thread, the head of which fits in an under cut
groove in the face of the spindle standard, while the shank passes
through the block and carries a nut in a similar manner to the before-
described attachment of the slide ring. Instead of passing the brush
from the back through a closed slot in the block, as heretofore, the block
is formed with a groove or slot open at the top, into which the brush
can consequently be inserted from the top, thus greatly facilitating its
introduction and removal. The block is formed at bottom with a
chamfered or rounded projecting edge, so as to prevent the catching of
the loop thereon.
Another part of my Invention has reference to the cloth plate. This
has heretofore been secured by means of screws passing through holes
in the plate and screwed into the spindle standards. As these screws
have to be entirely withdrawn for removing the plate, and as the plate
has to be removed frequently, particularly in Wheeler and Wilson's
machines, this mode of fixing is inconvenient.
My present improvement consists in forming or fixing on the under
side of the cloth plate three pins, which fit accurately into corresponding
holes in the spindle standards, and are secured there by set screws, so
that by simply loosening the set screws the plate can be removed. The
needle plate is formed with two different sized needle holes, so arranged
at opposite sides and ends of the plate that when it is desired to change
the needle hole this is effected by reversing the position of the needle
plate in its groove. The needle plate is secured by a screw beneath the
cloth plate. The under thread is held by means of a slit in the edge of
the cloth plate instead of by a spring as heretofore.
Although I have described my improvements as principally applicable
to the Wheeler and Wilson machines yet it will be evident that they
may nearly all be applied with advantage to other descriptions of sewing
machines.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Michael Heinrich Kernaul in the Great Seal Patent
Office on the 15th June 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MICHAEL
HEINRICH KERNAUL, of Berlin, in the Kingdom of Prussia, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of December, in
the year of our Lord One thousand eight hundred and seventy, in the
thirty-fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Michael Heinrich Kernaul, Her special
licence that I, the said Michael Heinrich Kernaul, my executors, admi-
nistrators, and assigns, or such others as I, the said Michael Heinrich
Kernaul, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN SEWING MACHINES," upon the condition (amongst
others) that I, the said Michael Heinrich Kernaul, my executors or
administrators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Scal Patent Office
within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Michael Heinrich Kernaul, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the accom-
panying Sheet of Drawings and to the figures and letters marked thereon,
that is to say :—
t
My Invention has reference more particularly to that class of sewing
machines that work with a rotating hook, and which are generally
known as "Wheeler and Wilson machines."
It is very generally admitted that these machines would be not only
the most simple but also the most perfect machines in existence if all

page_text: parts thereof were of the same perfect construction as the rotating hook
and spool, and it has therefore been the object of my present Invention
to afford to all other parts of the machine, such a simplicity and
perfection in their construction as shall correspond with the perfection
attained by the rotating hook, as also to render this machine readily
applicable both to the lightest and to the heaviest work, such as can
now only be performed by the shuttle machines.
On the accompanying Drawing Figure 1 shews a plan of my improved
machine, wherein the cloth plate is shown in dotted lines; Figure 2
shews a back elevation; Figure 3 shews a side elevation; Figure 4
shews a transverse section; Figures 5 to 11 shew detached details.
Similar letters of reference indicate similar parts in each of the Figures.
One improvement consists in forming the driving pulley R with a
chequered" surface, as shewn in Figure 1, instead of covering the
same with leather, as heretofore, whereby the slipping of the belt is
effectually prevented.
Another improvement has for its object to attain great smoothness of
motion in the action of the excentric E and connecting rod Z, and
consists in forming the excentric with a spherical surface, as shewn at
Figure 4, upon which the connecting rod fits with a corresponding
spherical recess. The end of the connecting rod is cast with a fork at Z',
Figures 1 and 3, which when the screws, ¹, in the strap are loosened,
springs open sufficiently for the strap to clear the excentric. The
screw is always screwed up tight, and the fit of the strap upon the
excentric is regulated by the screw 2¹.
Another improvement consists in securing the cnd Z³ of the connecting
rod in the jaw of the arm A of the needle arm, spindle, or rocker A' by
means of a taper pins (Fig. 2) fitting with a cylindrical part through
the left hand jaw, and screwed with the reduced threaded portion &¹
through the right hand jaw, so that by turning the head m of the pin
with a spanner the taper portion is drawn into the taper eye of the
connecting rod, and thus any back lash through wear is prevented. The
pin is secured in position by the lock nut m¹.
Another improvement has reference to the bearings of the rocker A'.
The cylindrical ends of the rocker pass loosely through the uprights S, S',
and fit into hollows in the coned ends of the rim nuts M, M³, (Fig. 2,)
which are screwed on to reduced screwed extensions a, a', of the rocker,
the concd surfaces of the nuts M, M', fit into the correspondingly coned

page_text: outer ends of the holes in S, S¹, through which the rocker A¹ passes, and
these nuts thus constitute the bearings for the rocker, permitting of
perfect adjustment both for wear and for adjusting the position of the
rocker, while at the same time they afford considerable and therefore
more durable bearing surfaces as compared with the ordinary lathe
centres usually employed. The nuts M, M', are screwed up by hand,
and are secured in position by lock nuts m³, m³, on the projecting ends
of a, a¹, which nuts, as also the nut m¹ and head m of the connecting
rod pins are all made to fit the same spanner that is used for the screw
of the needle yoke.
Another improvement has reference to the tension pulley for the
upper thread. The construction of this pulley as at present employed,
has the disadvantage that it requires to be oiled, whereby it is liable to
become clogged, and to accumulate dirt, more particularly in the felt or
cloth discs employed, thus preventing the maintenance of a uniform
tension particularly when the machine has not been worked for some
time and the oil has become resinous or congealed.
According to the present improvement the two metal discs of the
pulley C. (Figs. 1 and 2) are screwed upon a boss C¹ of vulcanite,
horn, or material of a similar nature, which requires no oiling, and
against the reduced end surface of which bears the end of a sleeve C²,
covering the spiral spring C³, which is acted upon by a nut K, screwed
on to the end of the pin a carrying the pulley. This nut has a small
stud d, which fits into a slot in the end of the sleeve C2, as shewn, and
thus prevents the latter from turning independently of the nut. By
this construction a perfectly uniform tension is maintained at all times,
and a freedom from the accumulation of dirt is insured through the
absence of oiling and the covering up of the spring, besides presenting
a neater appearance to the eye than the construction heretofore
employed.
Another improvement consists in the application of a tension to the
lower thread, whereby the machine is enabled to perform the heaviest
work, such as can now only be done by the shuttle machine, and
whereby also any desired tightness of stitch may be attained, and the
position of the looping of the threads be regulated at will, either so as
to be situated in the middle of the work or on the one or the other
surface thereof as may be desired. For this purpose a pin or rod h
(Figure 4) is made to pass through a cavity of the front standard L,

page_text: and to bear with its end upon a rim upon the driving pulley R, against
which the rod is pressed by means of a spring h² in the cavity 1, bearing
against a collar h³ on the rod, and against the end of the regulating
bush screwed into the front end of the cavity, as shown. The rod h
passes through the regulating bush, and has formed on it's outer end a
finger ', which during a certain portion of the revolution of the hook G
is caused to press against the spool q¹, and thus by retarding its rotation
produces any desired degree of tension on the lower thread. For causing
such pressure of the finger on the spool to take place at the desired
moment, a notch or space (Fig. 1) is formed in the rim of the
pulley, so that when this notch arrives at or near its lowest position
during the revolution of the pulley R, it allows the spring h² to force the
rod through it, so as to bring the pressing finger in contact with
the spool, while on the further rotation of the pulley R the rounded edge
of the notch causes the rod h to be pushed back again so as to rest upon
the rim during the remaining portion of the revolution, during which
time consequently the finger h¹ is kept away from the spool, so as to
allow of the free passage of the loop of the upper thread over the spool.
As it is only necessary to apply the tension to the lower thread at the
moment when the loop of the upper thread is being tightened after it
has passed the loop check brush, it will be seen that by the above-
described action, the finger ¹ is caused effectually to accomplish its
objcct.
For regulating the pressure of the pressing finger upon the spool, and
consequently the degree of tension on the lower thread, the regulating
bush is screwed farther into or out of the recess / so as to compress
the spring more or less. This is effected by means of the pressing
finger itself, which is provided for this purpose with a small pin or
stud e fitting into a notch in the end of the bush v. By first turning
the finger (after withdrawing the slide ring B) from left to right until
it lics flat on the bed plate, then pulling the finger forward so as to draw
the pin c out of the notch in the bush, then turning the finger from
right to left until the pin c can again enter the notch, and lastly, by
bringing the finger into the upright position the tension will be
increased, while by performing the above operation in the contrary
direction the tension will be diminished. Furthermore, if it be not
desired to apply the tension at all, this is readily effected by drawing
back the finger ', so as to bring the pin c out of the notch of a, as

page_text: above described, and then turning the finger so as to lie flat on the bed
plate, whereby the end of the rod h is drawn out of contact with rim »
of the pulley. The slide ring B is notched at bottom, as shewn in
Figure 4, so as to allow of the action of the finger h¹ without interfering
with the proper position of the slide ring against the spool.
Should the machine be intended to do very heavy work with the lower
tension it would be necessary to introduce stronger springs than those
usually employed, both in the presser D and the tension pulley C; for
medium work, however, sufficient tension can be put on the upper
thread with the ordinary spring by screwing up the nut K of the tension
pulley. The application of the lower tension will be of great advantage
in machines for household use where the machine is required to be
applicable both for very light work and for very heavy work (such as
for making winter clothing, &c.) For very light work the finger /¹
would be put entirely out of action as before described. It will be seen
that the putting in and out of action of the lower tension can be effected
instantaneously and with the greatest case.
Another improvement consists in an improved mode of securing the
slide ring B, whereby this may be adjusted or removed more quickly
and with greater ease than in the arrangement now employed. The
bed plate L³ has for this purpose an undercut groove L* (Figs. 3 and 4)
formed in it, in which groove slides the head of a screw w screwing
through the lip B₁ of the slide ring and into the nut K', so that by
merely slightly turning this nut in one direction or the other the slide
ring is either fixed in position or is capable of being slid forward or
backward in the groove or it can be drawn back entirely out of the
groove. When drawn back the slide ring may, if preferred be made to
turn round sideways on the screw, so as to obviate the necessity of
withdrawing it entirely from the groove, though it is so easily removed
and replaced that this is hardly necessary. The screw w is by preference
formed with a left-handed thread, so that for fixing the slide ring the
nut may be turned in the same direction as the ordinary screw.
For accurately adjusting the slide ring relatively to the spool an
adjustable stop screw L³ is provided in the groove L' as shewn, against
which stop the head of the screw w bears. I do, however, not claim
this last named contrivance as part of my present Invention.
Another improvement consists in an improved construction of the
silent feed whereby this is rendered more simple in arrangement than

page_text: the arrangements described in Newton's Patents, No. 970 of 1867, and
960 of 1870, and whereby also a perfectly parallel.vertical motion of
the "dog" or toothed surface is attained. For this purpose the " dog"
'
is formed as a rectangular block p (Figs. 3, 4, 5, and 6), fitting in a
corresponding rectangular notch or recess in the front standard L, as
shown in Figure 3. The spindle g carries two excentrics or cams, one c
which may conveniently be formed on the pulley R, and the other c',
fixed on the spindle behind the rotating hook G and working in a
recess in the standard L. Both excentrics have exactly the same throw
and are in precisely the same angular positions on the spindle, so that
as this revolves the two excentrics raise the dog p in a perfectly parallel
manner for bringing it into action. On the back surface of the dog p
is a flat bell-crank lever p', p², (Figs. 1, 4, and 6,) turning on a
screw ³ (screwed into p, so as to press the lever tightly against the
surface of the dog. The short arm p³ of the lever carries a stud u which
presses against a cam surface 7¹ on the pulley R formed and acting in
a similar manner to the cam surface described in Newton's before-
mentioned Specifications for effecting the forward or feed motion of
the dog when in the raised position. The adjustment of the stud u on
the surface of the cam for increasing or decreasing the amount of feed
motion is effected by simply raising or depressing the long arm p² of
the lever which is caused to move with sufficient friction to insure that
it shall not shift unless moved by the hand. The backward motion of
the dog is effected by means of a spring n (Figs. 1 and 3) fitted into
a rccess n¹ in the standard L and acting upon the dog in a similar
manner to that described in Newton's Specification, No. 970, of 1867.
For steadying the dog during its vertical motion a small sliding plate q
situated beneath. it (shewn detached in plan and clevation at Figs. 7
and S) fits with its ends in grooves y, y', (Fig. 3) in the recess of
the standard L, and has a pin o fitting through a hole o¹ in the dog, so
that this slides up and down upon such pin while at the same time the
plate q slides backwards and forwards with the dog.
If a vertical adjustment is desired for the dog this may be effected
cither simply by inserting a packing piece underneath the toothed
plate p' thereof, or by dividing the block p horizontally into two parts
connected together by two screws so arranged that by turning the
screws the upper part may be raised away from the lower part. Such
arrangement is indicated at Figure 5*, the screws p³ being screwed into
the upper part p of the dog while they are free to turn in the lower

page_text: part p, but are secured therein by pins p' fitting in a circular groove in
the screw as shewn.
Another improvement has for its object to facilitate the adjustment
or removal of the loop check brush. The block or segment B of the
brush is secured in position by a screw 2. Figs. 3 & 11 (by pre-
ference with left-handed thread) having a head ³ fitting in an undercut
curved groove L' in the face of the standard L and screwing through
the segment B, the front end of the shank having a notch to receive
the screwdriver, as shewn, so that by slightly turning the screw 62 in
one direction or the other the segment B² may be either fixed in position
or be adjusted up or down or be withdrawn entirely from the groove L
(which is open at top) in a similar manner to the arrangement of the
slide ring B, before described. Instead of passing the brush B³ from
the back of the segment through a closed slot the slot is formed open
at top, as shewn at Figure 11, so that the brush can be inserted from the
top, thus greatly facilitating its introduction or removal without injury
to the bristles. I do, however, not claim the open slot as part of my
Invention. The brush is secured in position by the scrow . The
segment is, by preference, formed at bottom with a rounded projecting
edge b³, in order to prevent any catching of the loop of the upper thread
thereon.
Another improvement has reference to the cloth plate. This has
heretofore been secured by means of three screws passing through holes
in the plate and screwing into the top of the standards L, L'. As these
screws have to be withdrawn entirely for removing the plate and as the
plate has to be removed frequently this mode of fixing is troublesome
and the screws are apt to get mislaid.
My present improvement consists in forming or fixing on the under
side of the plate T two pins or studs t (Figs. 9 and 10), which fit
accurately into corresponding holes t', t, formed in the standards 'L, L',
and are there secured by means of set screws b, b', screwing through the
standards L, L. By this arrangement the cloth plate can be removed
with great facility by simply loosening the set screws b, b³, and raising
the plate so as to draw the pins out of the holes . To facilitate this
the presser D is arranged to be capable of being turned round in its
socket away from the cloth plate as is now done in some sewing
machines. In the present instance this is effected by fixing at the top
of the presser arm N' a pin N² (Fig. 1) which when the presser is

page_text: in position over the cloth plate passes through a hole in the presser
head D, and thus holds the presser in that position. For turning the
presser
off the cloth plate it is raised by hand by means of the head D
until this is drawn off the pin N°, when the presser can be turned and
is held in such raised position by the nut D resting upon the top of
the pin. Or for increased steadiness two such pins N° may be used as
at Figure 1.
Another improvement consists in forming the needle plate T
(Figs. 9 and 10) with two different sized needle holes t², t, on opposite
sides of the aperture through which the teeth of the dog p project and
in forming the two ends of the plate with precisely the same con-
figuration, as shewn, so that its position can be reversed in the cloth
plate in order to bring the one or the other needle hole under the
needle as may be required. By this means one single needle plate is
made to serve in place of two separate plates of present construction.
The needle plate is secured in position by means of a screw n³ on the
under side of the cloth plate arranged either as shewn in dotted lines
at Figure 3, or as shown at Figures 9 and 10. is a small slot in the
edge of the cloth plate for holding the under thread in place of the
spring employed heretofore.
When my before-described improved sewing machine with tension
mechanism to the lower thread is to be adapted for heavy work for
manfacturing purposes I prefer to construct the same of larger
dimensions than shewn on the Drawings, say, about two-thirds larger,
in which size I believe it will be found to be the best and cheapest
machine for such purposes.
Although I have described my several improvements as principally
applicable to machines working with a rotating hook and spool, yet it
will be evident that some of them, such as those referring to the cloth
plate, the tension pulley, the excentric and connecting rod, and the
bearings to the rocking spindle may also be applied to such other
descriptions of sewing machines wherein any one or more of these devices
are employed.
Having thus described the nature of my Invention and in what
manner the same is to be performed, I wish it to be understood that I
do not limit myself to the combination of my several herein-before
described improvements, as shewn on the accompanying Drawings, as
it will be evident that any one or more of my improvements may be

page_text: employed separately from such combination, I wish also to observe
that since filing my Provisional Specification I have had reason to
believe that the improvements herein-before described with reference
to the driving pulley with chequered surface and the reversible needle
plate with two needle holes may not be so novel as at the time of filing
my Provisional Specification I considered them to be, and I do therefore
not claim these devices as part of the present Invention, nor do I claim
as part of my Invention the before-described device for turning the
presser D in its socket and maintaining it in its raised position off the
cloth plate, but what I claim is,-
First. Constructing the excentric E and excentric strap Z with
spherical surfaces, substantially as and for the purposes set forth.
Second: Securing the connecting rod Z to the rocker arm A by
means of a taper pin 8 passing through the taper eye Z of the connecting
rod and screwing into the one jaw of the arm A, the said pin being
turned by the head m and secured by the lock nut m³, substantially as
set forth.
・
Third. Providing the needle arm spindle or rocker A' with conical
nuts M, M¹, screwing in an adjustable manner on to the ends of the
rocker and fitting into conical holes in the uprights S, S¹, substantially,
as and for the purposes set forth.
Fourth. Constructing the tension pulley C with a boss C₁ of vulcanite,
horn, or material of a similar nature; substantially as and for the purposes
set forth.
Fifth. The employment of a sleeve C covering the spring C³ to the
tension pulley and operating in combination with nut K, substantially
as set forth.
Sixth. The employment of a pressing finger ' or equivalent device
for applying a tension to the lower thread during a certain portion of
the revolution of the rotating hook, substantially as set forth.
Seventh. Actuating the pressing finger h¹ by means of a rod h
operating in combination with the spring and notched or recessed
rim on the driving pulley, substantially, as and for the purposes set
forth.
Eighth. The notched regulating bush x operated by the pressing
finger hand pin c, substantially as set forth.

page_text: Ninth. Securing the slide ring B by means of a screw w fitting with
its head in an undercut groove L in the. bed plate and operated by a
nut K', substantially as set forth.
Tenth. Constructing the dog p of the silent feed as a rectangular
block sliding in a recess in the standard L and operating in com-
bination with two excentrics c, c¹, sliding plate q, and pin o, substantially
as set forth.
Eleventh. Regulating the feed motion by means of a lever p¹, p³,
with stud secured to the dog p by a screw 2³ and operating substan-
tially as set forth.
Twelfth. Securing the segment B¹ of the loop check brush by means
of a screw 6 having a head fitting into an undercut groove L in the
standard L and operating substantially as set forth.
Thirteenth. Securing the cloth plate T by means of pins't fixed to
the under side thereof fitting into holes in the standard L and held
therein by means of set screws 6 or equivalent devices.
In witness whereof, I, the said Michael Heinrich Kernaúl, have
hereunto set my hand and seal, this Third day of May, in
the year of our Lord One thousand eight hundred and seventy-
one.