IMPROVEMENTS IN SEWING MACHINES
Year: 1881

page_text: <<
LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of IMPROVEMENTS
IN SEWING MACHINES." A communication from abroad by Auguste Jacques
Hurtu, of Paris, France.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 2nd February 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN SEWING MACHINES."
munication from abroad by Auguste Jacques Hurtu, of Paris, France.]
[A com-
This Invention relates to improvements in sewing machines of that class in
which a circular or stationary shuttle is used, and the chief distinctive feature of
this Invention consists in making the looper shaft in two parts, connected together
in such manner that while the one, hereafter distinguished as the main shaft,
receives continuous uniform rotary motion, the other which carries the hook and is
hereafter called the looper shaft or looper, receives at each revolution a slower or
faster motion than the first, as may be required, in order that the needle thread
shall be thrown rapidly off the shuttle. The other distinguishing features consist,
1st, in the employment of a shuttle notched or recessed at the periphery for the
passage of the arm which carries the two halves of the shuttle which permits of a
shorter looper arm; 2nd, in the employment for the treadle shaft of spherical
bearings, as hereafter described; 3rd, in the employment of a special construction
of shuttle capable of containing more thread than those at present in use.
accelerated or retarded motions of the looper shaft are obtained by the aid of
suitable cams, in order to time the parts as required for the passage of the threads
either faster or slower as desired. The looper shaft may or may not be placed in a
line with the main shaft which receives continuous motion.
The
By using a metallic spool of large diameter and of short length a considerable
quantity of thread may be contained, the spool being enclosed in a case or cylinder
having a suitable slit.
The Invention is illustrated in the accompanying Drawings. In the first

page_text: arrangement shown in the main and looper shafts are in a line, and in the
second arrangement they are not, but are so coupled as to enable the looper
shaft to move at an irregular speed.
Figure 1 is a central longitudinal vertical section of a machine on this system, in
which motion is transmitted to the looper shaft by means of a stationary double
cam; Figure 2 is a plan, and Figure 3 a transverse section of same taken through
the cam which operates the needle bar; Figure 4 is a section of the bed plate taken
on the line 1-2, Figure 2; and Figure 5 a transverse section of same on line 3-4,
Figure 2; Figures 6, 6a, and 6b show a longitudinal section, end view, and plan of
the looper mechanism.
B is the shuttle containing the spool. It has a circular opening in one side of
sufficient size for the introduction of the spool. D is the main shaft upon which
are mounted the cams for operating the needle bar, looper, and take up. The shaft
is made hollow, and through it passes another shaft D¹ carrying at one end the
looper H by which the thread is passed over the shuttle, and at the other end a
bevel pinion G which is operated by a toothed segment F provided with an arm
carrying a friction roller engaged in the cam E, by which a variable circular motion
is imparted to the looper. This cam is formed in two parts adjustable to prevent
back-lash, while allowing of the free motion of the roller. I, feed claw attached to
an arm K pivoted on centres upon a double lever L, which is similarly pivoted
below the bed plate, and oscillates to permit of the horizontal motion of the feed
claw. The arm of the feed claw rests at its other end upon the cam Q, a steel
spring R being interposed between the two. Z, presser foot lifter having two arms
to enable it to be operated by either hand as inost convenient. The main shaft
mounted beneath the bed plate carries the band pulley, the cam for operating the
take up, and the needle bar, the cam for varying the rotation of the looper, and
the cam for giving the vertical motion to the feed claw made in one with the cam
for giving the horizontal motion. The stitch regulator consists of a worm actuating
a toothed segment, which through the medium of a connecting rod and lever
presents the feed mechanism to a larger or smaller part of the cam.
Figures 7, 7, and 7b show a longitudinal and transverse section, and also
another longitudinal section of an arrangement by which the movement of the
looper is produced by means of a stationary cam 4 formed on the bearing i of the
main shaft beneath the bed plate j, the variable motion being imparted by a
toothed segment operated by said cam 4, and gearing with a pinion y on the
looper shaft 2.
Figures S, Sa, and 8b, show two side views and end view of the main shaft h, and
Figure 9, a view of the looper shaft ; Figures 10, 10ª, 10b, show a plan, end
view, and side view of the toothed segment x; Figures 11, 11a, 11b, show a side
view, transverse section, and plan of another arrangement in which the variable
motion of the looper shaft is obtained, by means of a longitudinally movable cam 5
carrying a nut acting directly on a multiple threaded screw 6 of rapid pitch formed
on the looper shaft z; Figures 12, 12a, and 12b, show two side views and an end
view of the main shaft; Figure 13, a side and end view of the looper shaft, and
Figure 14, a side and end view of the movable cam 5; Figure 15 is a longitudinal
section and end view of another arrangement in which the variable motion of the
looper shaft is obtained by means of a cam groove 7 formed on the bearing i acting
on a toothed segment 8 gearing with a pinion 9 keyed on the looper shaft ;
Figures 16, 16, 16a, show two side views and an end view of the main shaft;
Figure 17 represents the looper shaft with spur pinion 9; Figure 18 is a transverse
section and face view of the box which carries the toothed segment 8, and
Figure 19 is a face and edge view of said segment; Figure 20 shows a transverse
vertical section and face view of the shuttle employed in this machine; Figure 21
represents an edge and face view of the shuttle spring; Figure 22 is a transverse
section and face view of the spool. The shuttle B to contain the spool is of
bi-convex form, and has a circular opening in one side large enough to admit the
spool,

page_text: Figures 23 to 25 show different arrangements which may be employed for
facilitating the mounting and dismounting of the shuttle and shuttle holder;
Figures 23, 23, 24, and 25, show several views of a hinged arrangement. In
these Figures the shuttle X is shown as enclosed between a double holder a, b,
which requires to be opened for the purpose of inserting or removing the shuttle.
Upon the closed side of the shuttle is fixed a vertical extension 1, Figure 20,
serving to prevent the shuttle from turning, and also for the attachment of the
tension spring C for the under thread. This spring is received at its lower end in
a recess in the shuttle, the tension being regulated by a screw at its centre; it is
also provided with suitable notches for the passage of the thread and ensuring its
proper position beneath the spring. One portion of the periphery of the shuttle
is recessed or depressed to receive the fixed part of the shuttle holder, and thereby
reduce to a corresponding extent the radius of the looper.
The thread spool A, Figure 22, is formed of two discs united at the centre by a
hollow axis turning upon the stud in the shuttle; K, K', are thumb pieces upon
the holder a, a, to enable it to be readily separated from b, b. The shuttle holder S,
Figures 26, 20, 26, is formed of two concave clips T, T', of which T is movable
for the insertion and removal of the shuttle; its position is regulated by a screw U,
and it is pressed by a spring V towards T¹, the other end of said spring pressing
against a bolt X. In this manner the necessary play is left, between the shuttle
and the holder for the passage of the thread. The fixed part of the holder T' is
carried by an arm concentric with the looper, and lodging in the recess 2 of the
shuttle. The bolt X serves to fix the position of the shuttle holder upon the bed
plate, the spring V also pressing upon it causes the nib X1, Figure 26b, to engage
in a notch in the bed, and thus firmly fixes the shuttle holder. By pressing on X,
and at same time pulling on the shuttle holder, it may be readily removed.
Figures 27, 27, 27, show a separate side, end, and plan view of the stitch
regulating mechanism represented in the machine first described (Figures 1 to 6),
the same letters of reference being used to represent the same parts. 3, Figure 28,
is a plate for covering the small lubricating washers applied to. the presser foot
and needle bar; this plate is fixed by a single screw at the middle, as shown in
Figure 2. Between the feed claw and the part which rests upon the cam Qis
placed the lever M, which is attached at the one end to a connecting rod N, and carries
at its other end an arm upon which acts the cam J. The feed claw carrier K is
pressed down upon the cain and against the cam J by a spring Y placed at a.
suitable inclination. L, oscillating lever; O, toothed segment with which gears a
worm P turned by a milled knob P above the bed plate. This segment is con-
nected by rod N to lever M, and it has a mark on its edge which by turning
knob P may be brought opposite to any of a series of graduations upon the bed
plate, whereby the stitch is regulated and the different sizes indicated. By this
arrangement the adjustment of the stitch is easy, and once adjusted is not liable to
variation during the working.
Figures 29, 30, 31, and 32, represent a longitudinal section, plan, end view, and
detail of a modified arrangement of the machine in which the motion of the main
shaft is transmitted to the looper shaft by means of a series of spur wheels, the
machine being intended for sewing arm holes.
The shuttle holder in this arrange-
ment is the saine as that in Figures 26, 26ª, 26³.
In Figures 29, 30, 31, and 32, 1 is the bed; m, the main shaft receiving continuous
uniform rotary motion; n, o, is the looper shaft, the part n, which carries the
looper A, being fitted to turn freely in the tubular part o, which turns in a
bearing 2 cast on or attached to the underside of bed ; r, pinion fixed on shaft n
at the opposite end to the looper; 8, cam groove in bearing p, or the cam may be
made separate and fixed to the bearing; t, spur wheel on tubular part o of looper
shaft; u, spur wheel on main shaft m; v, intermediate wheel gearing with wheels t
The wheels u, v, t, have equal numbers of teeth, and transmit motion from
the main shaft to the looper shaft; a, toothed segment pivoting at y upon wheel t,
and gearing with pinion ; 2, friction roller running in cam groove 8, and
and u.

page_text: turning upon a stud fixed on segment x, extending through an elongated slot in
wheel t.
The action is as follows:-When by the rotation of wheel t the friction roller =
is carried round in the concentric portion of the cam groove 8, the two parts n, o,
of the looper shaft turn together at the same speed as the main shaft m, but
immediately the roller enters a part of the cam groove of different radius, the
segment x will rotate pinion in the one or other direction, thus imparting to the
part n of the shaft, and consequently to the looper A, either a faster or slower
motion than that of the tubular part o, which enables the thread to be released.
The improved bearings for the treadles and crank shaft are designed to lessen
the friction of these parts. 1st, the treadles are mounted on a pair of spherical
metal bearings which prevents their setting fast; the bearings are lubricated with
oil, but owing to their relatively small curved bearing surface the motion of the
machine will not be affected even should the oil become foul by use. Moreover,
as the centre of oscillation of the treadle is raised, the motion of the leg is very
slight and less fatiguing. 2nd, the crank shafts are furnished with spherical
bearings which adjust themselves to their proper position, and thus compensate for
any want of truth in the fitting together of the parts or of the pivots.
Figures 33 and 34 show front and side views of a sewing machine stand with a
single treadle, having the improved self adjusting bearings for the crank shaft, and
spherical bearings for the treadle.
Figures 35, 35, 35b, show longitudinal and transverse sections and plan of the
self adjusting bearings for the crank shaft drawn to a larger scale. A, A, standards
braced together by frames B, C; D, crank; E, band wheel; F, bearing bracket;
G, treadle; H, spherical treadle bearings; I, connecting rod; J, cap of bearing;
K, bearings of spherical form externally so as to be self adjusting.
Figures 36 and 37 show front and side views of a sewing machine stand having
a pair of treadles mounted on ball bearings, the crank shaft being also mounted in
spherical self adjusting bearings.
Figures 38, 38, 38b, show longitudinal and transverse sections and plan of the
crank shaft bearings drawn to a larger scale.
Figures 39, 39, 39b, show details. A, A, standards; B, C, cross frames; D,
crank shaft; E, band wheel; F, F, bearing brackets; G, G, treadles; H, H, spherial
treadle bearings; I, I, connecting rods; J, hemispherical stud forming a ball and
socket joint between the connecting rod I and the treadle, the parts being held
together by a clamp K; L, oil passage; M, oil cup for the crank shaft bearing;
N, spherical self adjusting crank shaft bearing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the
2nd August 1881.
A com-
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN SEWING-MACHINES."
munication from abroad by Auguste Jacques Hurtu, of Paris, France.
This Invention relates to improvements in sewing machines of that class in
which a circular or stationary shuttle is used, and the chief distinctive feature of
this Invention consists in making the looper shaft in two parts, connected together
in such manner that while the one, hereafter distinguished as the main shaft,
receives continuous uniform rotary motion, the other which carries the hook and is
hereafter called the looper shaft or looper, receives at each revolution a slower or
faster motion than the first, as may be required, in order that the needle thread
shall be thrown rapidly off the shuttle. The other distinguishing features consist,
1st, in the employment of a shuttle notched or recessed at the periphery for the
passage of the arm which carries the two halves of the shuttle, which permits of a
shorter looper arm; 2nd, in the employment for the treadle shaft of spherical
bearings, as hereafter described; 3rd, in the employment of a special construction
of shuttle capable of containing more thread than those at present in use.
The accelerated and retarded motions of the looper shaft are obtained by the
aid of suitable cams in order to time the parts as required for the passage of the
threads, either faster or slower as desired. The looper shaft may or may not be
placed in a line with the main shaft which receives continuous motion. By using
a metallic spool of large diameter and of short length a considerable quantity of
thread may be contained, the spool being enclosed in a case or cylinder having a
suitable slit.
The Invention is illustrated in the accompanying Drawings. In the first
arrangement shown the main and looper shafts are in a line, and in the second
arrangement they are not, but are so coupled as to enable the looper shaft to move
at an irregular speed. Figure 1 is a central longitudinal vertical section of a
nachine on this system, in which motion is transmitted to the looper shaft by
ineans of a stationary double cam; Figure 2 is a plan, and Figure 3 a transverse
section of same taken through the cam which operates the needle bar; Figure 4
is a section of the bed plate taken on the line 1-2, Figure 2; and Figure 5 a trans-
verse section of same on line 3-4, Figure 2; Figures 6, 6º, and 6b, show a
longitudinal section, end view, and plan of the looper mechanism.
B is the shuttle containing the spool. It has a circular opening in one side
of sufficient size for the introduction of the spool. D is the main shaft, upon which
are mounted the cams for operating the needle bar, looper, and take up. The shaft
is made hollow, and through it passes another shaft D' carrying at one end the
looper H, by which the thread is passed over the shuttle, and at the other end a
bevel pinion G which is operated by a toothed seginent F provided with an arm
carrying a friction roller engaged in the cam E, by which a variable circular motion
is imparted to the looper. This cam is formed in two parts, adjustable to prevent
back-lash, while allowing of the free motion of the roller. I, feed claw attached
to an arm K pivoted on centres upon a double lever L, which is similarly pivoted
below the bed plate, and oscillates to permit of the horizontal motion of the feed
claw. The arm of tho feed claw rests at its other end upon the cam Q, a steel
spring R being interposed between the two. Z, presser foot lifter having two arms
to enable it to be operated by either hand, as most convenient. The main shaft
mounted beneath the bed plate carries the band pulley, the cam for operating the
take up, and the needle bar, the cam for varying the rotation of the looper, and the
cam for giving the vertical motion to the feed claw made in one with the cam for

page_text: giving the horizontal motion. The stitch regulator consists of a worm actuating a
toothed segment, which through the medium of a connecting rod and lever
presents the feed mechanism to a larger or smaller part of the cam. Figures 7, 7ª,
and 7, show a longitudinal and transverse section and also another longitudinal
section of an arrangement by which the movement of the looper is produced by
means of a stationary cam 4 formed on the bearing i of the main shaft / beneath
the bed plate j, the variable motion being imparted by a toothed segment & operated
by said cam 4, and gearing with a pinion y on the looper shaft 2.
Figures S, S, and Sh, show two side views and end view of the main shaft h,
and Figure 9 a view of the looper shaft ; Figures 10, 10%, 10b, show a plan, end
view, and side view of the toothed segment ; Figures 11, 11, 11b, show a side
view, transverse section, and plan of another arrangement in which the variable
motion of the looper shaft is obtained by means of a longitudinally movable cam 5
carrying a nut acting directly on a multiple threaded screw 6 of rapid pitch formed
upon the looper shaft ; Figures 12, 12, 12b, show two side views and an end
view of the main shaft; Figure 13 a side and end view of the looper shaft 3,
and Figure 14 a side and end view of the movable cam 5; Figure 15 is a longi-
tudinal section and end view of another arrangement in which the variable motion
of the looper shaft is obtained by means of a cam groove 7 formed on the bearing i
acting on a toothed segment 8 gearing with a pinion 9 keyed on the looper
shaft; Figures 16, 10, 16, show two side views and an end view of the main
shaft; Figure 17 represents the looper shaft with spur pinion 9; Figure 18 is a
transverse section and face view of the box which carries the toothed segment 8,
and Figure 19 is a face and edge view of said segment; Figure 20 shows a trans-
verse vertical section and face view of the shuttle employed in this machine;
Figure 21 represents an edge and face view of the shuttle spring; Figure 22 is a
transverse section and face view of the spool. The shuttle B to contain the spool
is of bi-convex form, and has a circular opening in one side large enough to admit
the spool. Figures 23 to 25 show different arrangements which may be employed
for facilitating the mounting and disinounting of the shuttle and shuttle holder;
Figures 23, 23, 24, and 25 show several views of a hinged arrangement. In these
Figures the shuttle X is shown as enclosed between a double holder a, b, which
requires to be opened for the purpose of inserting or removing the shuttle. Upon
the closed side of the shuttle is fixed a vertical extension 1, Figure 20, serving to
prevent the shuttle from turning, and also for the, attachment of the tension
spring C for the under thread. This spring is received at its lower end in a recess
in the shuttle, the tension being regulated by a screw at its centre; it is also
provided with suitable notches for the passage of the thread and ensuring its
proper position beneath the spring. One portion of the periphery of the shuttle is
recessed or depressed to receive the fixed part of the shuttle holder, and thereby
reduce to a corresponding extent the radius of the looper.
The thread spool A, Figure 22, is formed of two discs united at the centre by a
hollow axis turning upon the stud in the shuttle; K, K¹, are thumb pieces upon
the holder a, a, to enable it to be readily separated from b, b. The shuttle holder S,
Figures 26, 26a, 26b, is formed of two concave clips T, T, of which T is movable
for the insertion and removal of the shuttle; its position is regulated by a screw U,
and it is pressed by a spring V towards T, the other end of said spring pressing
against a bolt X. In this manner the necessary play is left between the shuttle
and the holder for the passage of the thread. The fixed part of the holder T¹ is
carried by an arm concentric with the looper, and lodging in the recess 2 of the
shuttle. The bolt X serves to fix the position of the shuttle holder upon the bed
plate the spring' V also pressing upon it causes the nib X', Figure 20b, to engage
in a notch in the bed and thus firmly fixes the shuttle holder. By pressing on X,
and at same time pulling on the shuttle holder it may be readily removed.
Figures 27, 27, 27b, show a separate side, end, and plan view of the stitch
regulating mechanism represented in the machine first described (Figures 1 to 6),
the same letters of reference being used to represent the same parts. 3, Figure-28,

page_text: is a plate for covering the small lubricating washers applied to the presser foot
and needle bar; this plate is fixed by a single screw at the middle, as shown in
Figure 2. Between the feed claw and the part which rests upon the cam Q is
placed the lever M, which is attached at the one end to a connecting rod N, and
carries at its other end an arm upon which acts the cain J. The feed claw
carrier K is pressed down upon the cam Q and against the cam J by a spring Y,
placed at a suitable inclination. L, oscillating lever; O, toothed segment, with
which gears a
worm P turned by a milled knob P above the bed plate. This
segment is connected by rod N to lever M, and it has a mark on its edge which
by turning knob P may be brought opposite to any of a series of graduations upon
the bed plate, whereby the stitch is regulated and the different sizes indicated.
By this arrangement the adjustment of the stitch is easy, and once adjusted is not
liable to variation during the working..
Figures 29, 30, 31, and 32, represent a longitudinal section, plan, end view, and
detail of a modified arrangement of the machine, in which the motion of the main
shaft is transmitted to the looper shaft by means of a series of spur wheels, the
machine being intended for sewing arm holes.
The shuttle holder in this arrange-
ment is the same as that in Figures 26, 26a, 26b. In Figures 29, 30, 31, and 32,
Z is the bed; m, the main shaft receiving continuous uniform rotary motion; n, o,
is the looper shaft, the part n which carries the looper A. being fitted to turn freely
in the tubular part o, which turns in a bearing p cast on or attached to the under-
side of bed ;, pinion fixed on shaft n at the opposite end to the looper; 8, cam
groove in bearing P, or the cain may be made separate and fixed to the bearing;
t, spur wheel on tubular part o of looper shaft; u, spur wheel on main shaft m;
v, intermediate wheel gearing with wheels and u. The wheels u, v, t, have equal
numbers of teeth and transinit motion from the main shaft to the looper shaft;
, toothed segment, pivoting at y upon wheel tand gearing with pinion; friction
roller running in cam groove 8, and turning upon a stud fixed on segment x,
extending through an elongated slot in wheel t.
The action is as follows:-When by the rotation of wheel t the friction roller
is carried round in the concentric portion of the cam groove 8, the two parts n, o,
of the looper shaft turn together at the same speed as the main shaft m, but
immediately the roller enters a part of the cam groove of different radius the
segment will rotate pinion in the one or other direction, thus imparting to the
part of the shaft, and consequently to the looper A, either a faster or slower
motion than that of the tubular part o, which enables the thread to be released.
The improved bearings for the treadles and crank shaft are designed to lessen the
friction of these parts. 1st, the treadles are mounted on a pair of hemi-spherical
metal bearings which prevents their setting fast; the bearings are lubricated with
oil, but owing to their relatively small curved bearing surface the motion of the
machine will not be affected even should the oil become foul by use. Moreover,
as the centre of oscillation of the treadle is raised the motion of the leg is very
slight and less fatiguing; 2nd, the crank shafts are furnished with spherical
bearings which adjust themselves to their proper position, and thus compensate for
any want of truth in the fitting together of the parts or of the pivots.
Figures 33 and 34 show front and side views of a sewing machine stand with a
single treadle, having the improved self adjusting bearings for the crank shaft and
hemi-spherical bearings, for the treadle.
Figures 35, 35, 35b, show longitudinal and transverse sections and plan of the
self adjusting bearings for the crank shaft drawn to a larger scale. A, A, standards
braced together by frames B, C; D, crank; E, band wheel; F, bearing bracket;
G, treadle; H, hemi-spherical treadle bearings; I, connecting rod; J, cap of
bearing K, bearings of spherical form externally, so as to be self adjusting.
Figures 36 and 37 show front and side views of a sewing machine stand having
a pair of treadles mounted on ball and socket bearings, the crank shaft being
mounted in spherical self adjusting bearings; Figures 38, 38", 38b, show longi-
tudinal and transverse sections and plan of the crank shaft bearings drawn to a

page_text: larger scale; Figures 39, 39, 39b, show details of the joint of the connecting rod
with the treadle.
A, A, standards; B, C, cross frames; D, crank shaft; E, band wheel; F, F,
bearing brackets; G, G, treadles; H, H, ball and socket treadle bearings; I, I, con-
necting rods; J, hemispherical stud forming a ball and socket joint between the
connecting rod I and the treadle, the parts being held together by a clamp K;
L, oil passage M, oil cup for the crank shaft bearing. The treadle bearings H are
similar to the joint J of the treadle with connecting rod.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is,--
1st. The respective combinations and arrangements of parts constituting the
respective improvements in sewing machines, substantially as hereinbefore described
and illustrated in the Drawings annexed.
2nd. The employment of the looper shaft made in two parts, so connected and
operated that the one part receiving continuous uniform rotary motion transmits
to the other part which carries the looper a periodically accelerated and retarded
motion, substantially as and for the purpose specified.
3rd. The combination of the shuttle, notched or recessed, to give passage to the
arm, which connects the two parts of its holder with the looper carried by the
looper shaft in order to throw the needle thread quickly off the shuttle.
4th. The combination of the shuttle of the particular form shown and spool so
. arranged as to hold a large quantity of thread.
5th. The combination of the tubular main shaft D, the looper shaft D¹ mounted
therein and carrying the looper H with the pinion G, toothed sector F, and cam E,
substantially as herein described and shown in Figures 1 to 6. for the purpose
specified.
6th. The arrangement, constructed and operating substantially as described and
illustrated in Figures 23 to 25, for inserting and removing the shuttle.
7th. The arrangement of shuttle holder, shown in Figure 26, formed of a fixed
and movable part in combination with the adjusting screw U, spring V, bolt X,
and nib X', substantially as and for the purpose specified.
8th. The arrangement, shown in Figures 27 and 28, of stitch regulating
mechanism adjusted by means of the combination of knob P, worm P¹, and toothed
sector moving in relation to a scale on the bed plate, substantially as
specified.
9th. The combination and arrangement of mechanism for transmitting variable
rotary motion to the looper shaft, substantially as described and shown in Figures
29 to 32.
10th. The combination of the toothed sector x with the wheel t and the
pinion 7, and of the cam s with the roller z for imparting a periodically accelerated
and retarded motion to the looper A, substantially as described and shown in
Figures 29 to 31.
11th. The construction of ball and socket bearings for the treadle, substantially
as shown in Figures 36, 37, 39, 39ª, 39b.
12th. The construction of spherical bearings for the crank shaft, substantially as
shown in Figures 38, 38, 386, for the purpose specified.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Second day of August, in the year of our Lord One
thousand eight hundred and eighty one.
A. M. CLARK. (L.S.)