IMPROVEMENTS IN SEWING MACHINES.
Year: 1867

page_text: LETTERS PATENT to Thomas Bletcher, of Peterboro', Canada, now of
No. 8, Southampton Buildings, Chancery Lane, in the County of
Middlesex, Engineer, for the Invention of "IMPROVEMENTS IN SEWING
MACHINES.'
Sealed the 17th March 1868, and dated the 19th September 1867.
PROVISIONAL SPECIFICATION left by the said Thomas Bletcher at the
Office of the Commissioners of Patents, with his Petition, on the 19th
September 1867.
I, THOMAS BLETCHER, of Peterboro', Canada, now of No. 8, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN SEWING MACHINES,"
to be as follows:-
These improvements relate to sewing machines which work with two threads
and produce a stitch known as the "lock stitch."
The said improvements consist chiefly in the novel construction and
arrangement of devices for effecting the required combination of the two threads,
and in the mechanism for operating the same. The upper thread is carried
by a vertically reciprocating needle; and is thereby passed through the cloth or
other material in the usual manner. The under thread is carried by a bobbin

page_text: which is supported to turn freely upon a pin or rod enclosed in a case or
holder; the latter is somewhat similar in form to the flying shuttle employed
in other sewing machines, but instead of being caused to move through the
loops of needle thread the said holder remains stationary while the successive
loops of thread are passed over it by means of a vibrating hook of peculiar
formation and a lever with elastic arms. The hook places the loop upon the
point of the bobbin case, and the elastic lever draws the said loop upward
between the said case and its support, and tightens the thread as each stitch
is formed. The book is fixed upon a vibrating shaft which also carries the
cams for operating the feed bar. The reciprocating needle which carries the
upper thread is fixed in a. sliding bar, and operated by an arm on the end
of another vibrating or rocking shaft whose motion is derived from a cam
attached to the driving 'pulley at the rear of the machine or from other
suitable devices. The said shaft is provided with a crank arm which is
connected by a rod or link to a similar arm on the shaft which operates the
feed bar and hook, and both shafts vibrate simultaneously; or the needle bar
may be operated by a rotating shaft geared in connection with the driving wheel.
The feed bar is formed with a broad flat web at one end; and is thereby
supported in a guide attached to the under surface of the cloth plate in the
proper position to be actuated by the cams on the lower rocking shaft. The
presser bar is forced down by a spiral spring, whose pressure is regulated
by means of a pin which may be inserted in any one of a series of holes
formed in the said bar. The presser foot is formed with grooves or pro-
jections at its sides, whereby a hemmer, a feller, a binder, friller, or other
device may be readily attached to and removed from the said foot. A device
for filling the bobbin is attached to the machine. The bobbin is supported
between a fixed centre and a spindle which is provided with a toothed or
friction wheel... When the bobbin is inserted. the. said wheel is pressed into
contact with the driving wheel of the machine and thereby caused to rotate,
but when the bobbin is. removed the said wheel is drawn out of contact with
the driving wheel by means of a spring. The parts of the mechanism are
supported upon a suitable frame which is preferably of an oval shape, and is
provided with a foot or stand whereby the machine. is secured to a table or
bench. The, bobbin case or holder is. supported in a nearly. vertical position
in a chamber or channel formed in a. bracket cast upon or attached to the
frame of the machine below .the cloth plate. The central pin. or spindle
which receives the bobbin is fixed in the front end or point of the case whose
other end is left open to allow the said bobbin to be conveniently inserted. and

page_text: removed. The bobbin is preferably formed of a small metal tube with a flange
at each end. The upper end of the bobbin lies near the under surface of the
cloth plate, and its thread is drawn, through a number of, small holes formed
in the case or in a web or flange on the exterior of the same. . The case or
holder is formed with: two lateral ribs or wings which project, into grooves
formed in the side of the chamber and, prevent the turning round of the said
holder; the latter is held and kept from falling out of the said chamber
by the pressure of a spring. which is attached to the back of the chamber,
and yields to allow the loops of needle thread to pass. up between the
case and chamber as each stitch is formed. The nose or lower end of
the case or holder is pointed and curved outward to facilitate the passing of
the thread loops over the same. The vibrating hook which brings down these
loops is formed and arranged to vibrate across the front of the said case, The
outer end of this hook is formed with a triangular piece. which is curved
laterally to correspond with the shape of the point of the bobbin case to allow.
it to work in close proximity to the same. The extremity of the 'hook; is
bent down outside this triangular piéce, and notches or recesses: are formed.on
each side of the latter. The loop of needle thread when caught by the hook
lies in these notches and behind the curved triangular piece, and a space is:
left between the thread and the back of the latter wherein the point. of
the bobbin case enters as the hook moves upward. Alever with elastic arms:
preferably formed of steel wire is pivoted to the frame in front of the needle
bar; one arm of this lever is formed with an eye; through which the needle"
thread passes, the said thread being also conducted through two fixed eyes or
guides arranged above and below the eye in the lever arm. The other arm
of the said lever is curved or bowed in its centre and is arranged to be acted'
upon by a pin or stud projecting from the needle bar or part attached to the
same; this stud strikes the curved lever arm at both its upward and down-
ward stroke, and the lever is so formed and arranged in relation to the other
parts of the mechanism as to be drawn back at the end of the upward
stroke of the projecting stud and pull the thread loop upward as the same is
passed by the vibrating hook over the point of the bobbin case. The action)
of the projecting stud or pin upon the elastic lever at the end of its down-*
ward stroke also causes the latter again to tighten the thread loop. as it'
is drawn behind the bobbin case, and to slacken the needle thread in
time to allow a fresh loop to be caught upon the vibrating hook. The:
feed bar is arranged outside the vibrating hook, the cams for operating
the said bar being fixed on the end of the lower rocking shaft. The feed bar!

page_text: is so formed and arranged that the teeth which act on the cloth lie between
the fulcrum of the said bar and the cams for operating the same.
By this
means the wearing away of the surface of the lifting cam is greatly reduced.
The feed bar is curved downward and provided with two jaws for one cam to
act upon in imparting the required endwise movement to the said bar while it
is lifted by the other cam. The feed is preferably regulated by a screw, which
projects through one of the two jaws of the feed bar. The latter is formed at
its other end with a broad flat piece or web, which is fitted to slide through a
guide attached to the under side of the cloth plate. The said web is curved
on its upper surface, and a spring attached to the cloth plate acts with just
sufficient pressure upon the bar to keep it properly in contact with the cam.
The rocking shaft which operates the needle bar is supported in suitable
bearings attached to the upper part of the frame. An arm on the front end
of this shaft works in a groove formed in a plate attached to the said bar, and
imparts thereto the required reciprocating motion. The rear end of this bar
is provided with another arm, which by preference carries a friction roller
arranged to run in a cam groove formed in the driving wheel. This groove
may be formed to produce two or more reciprocations. of the needle to one
revolution of the wheel. The shaft for operating the feed motion is carried in
bearings attached to the lower part of the frame, and the arm whereby this
shaft is connected to the upper shaft is fixed on its rear end in a convenient
position to be taken hold of by the rod which connects the: two shafts.
The series of holes in the presser bar are arranged one above the other, and
when the adjustable pin is inserted into either of these holes the spring bearing
on the said pin and upon the upper part of the frame causes the presser foot
to exert a pressure upon the cloth proportionate to the distance of the hole.
from the upper end of the spring. The presser bar is preferably provided with
a pin or feather, which projects into a groove in the bearing of the said bar
and prevents it's turning round. The bar is supported when raised by a
movable collar, which fits the upper end of the bar, and is provided with a pin
arranged to drop into a hole when the bar is down, the said collar being.
turned round on the bar when the latter is to be adjusted. The grooves in
the presser foot or the projections thereon are preferably made V-shaped, and
the flange of the hemmer or other device to be attached to the said foot is
made of corresponding form. These grooves or projections may extend
entirely or partially from end to end of the foot. The flange of the hemmer
or other device is preferably formed of sheet brass, steel, or other suitable
metal, with its sides bent or otherwise adapted to the shape of the presser

page_text: foot. The flange and foot are fitted together in such manner that the former
will readily slide end wise on the said foot, whereon it can be further secured;
by screws if desired....
The device for filling the bobbin is arranged at the rear of the machine.
The wheel on the adjustable spindle may be formed with teeth corresponding:
with other teeth on the driving wheel, or may be furnished with an india-
rubber band, which runs in contact with the periphery of the said.wheel.:
The spindle is supported in a bearing secured to the foot or, base of the frame,
and is formed with a concave centre to receive the end of the bobbin, which
is held while being filled by the pressure of the spring surrounding the said;
spindle.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed'
by the said Thomas Bletcher in the Great Seal Patent Office on the
18th March 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
BLETCHER, of Peterboro', Canada, now of No. 8, Southampton Buildings,
Chancery Lane, in the County of Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date, the Nineteenth day of September, in the year of our Lord,
One thousand eight hundred and sixty-seven, in the thirty-first year of Her,
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas Bletcher, Her special licence that I, the said Thomas Bletcher,,
my executors, administrators, and assigns, or such others as I, the said
Thomas Bletcher, my executors, administrators, and assigns,.should at any time;
agree with, and no others, from time to time and at all times thereafter
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 "IMPROVE-
MENTS IN SEWING MACHINES," upon the condition (amongst others) that
I, the said Thomas Bletcher, my executors or administrators, by an instru
inent 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 Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Thomas Bletcher, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Sheet of Drawings,
forming a part of this Specification:-
These improvements relate to sewing machines which work with two threads
and produce a stitch known as the "lock stitch."
The said improvements consist chiefly in the novel construction, arrange-
ment, and combination of devices for forming the stitches, and in the.
mechanism for operating the same. The upper thread is carried by a ver-
tically reciprocating needle, and is thereby passed through the cloth or.
other material in the usual manner. The under thread is carried by a
bobbin which is supported to turn freely upon a pin or rod enclosed in
a case or holder; the latter is somewhat similar in form to the flying
shuttle employed in other sewing machines, but instead of being caused to
move through the loops of needle thread the said holder remains stationary
while the successive loops of thread are passed over it by means of a vibrating
hook of peculiar formation and a lever with elastic arms. The hook places
the loop upon the point of the bobbin case, and the elastic lever draws the
said loop upward between the said case and its support and tightens the thread
as each stitch is formed; the hook is fixed upon a vibrating shaft which also
carries the cams for operating the feed bar. The reciprocating needle which
carries the upper thread is fixed in a sliding bar and operated by an arm on
the end of another vibrating or rocking shaft whose motion is derived from a
cam attached to the driving pulley at the rear of the machine or from other
suitable devices. The said shaft is provided with a crank arm which is con-
nected by a rod or link to a similar arm on the shaft for operating the feed
bar and hook, and both shafts vibrate simultaneously, or the needle bar may
be operated by a rotating shaft geared in connection with the driving wheel.
The feed bar is formed with a broad flat web at one end, and is thereby sup-
ported in a guide attached to the under surface of the cloth plate in the proper
position to be actuated by the cams on the lower rocking shaft. The presser
bar is forced down by a spiral spring whose pressure is regulated by means of
à pin which may be inserted in any one of a series of holes formed in the said
bar. The presser foot is formed with grooves or projections at its sides,
whereby a hemmer; a feller, a binder, friller, or other device may be readily
attached and removed from the said foot. A device for filling the bobbin is
attached to the machine. The bobbin is supported between a fixed centre and a

page_text: spindle which is provided with a toothed or friction wheel. When the bobbin
is inserted the said wheel is pressed into contact with the driving wheel of the
machine and thereby caused to rotate, but when the bobbin is removed the
said wheel is drawn out of contact with the driving wheel by means of a spring.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a plan of the top of my improved machine; Figure 2 is a side
elevation, and Figure 3 and end elevation of the same; Figure 4 is a. plan of
part of the said machine. with the cloth plate removed.; Figure 5 represents
a detached portion of the said machine; Figure 6 illustrates a modification of
part of the mechanism. Like letters indicate the same parts in each of the
Figures..
The parts of the mechanism are supported upon a suitable frame a, which
is preferably of an oval shape, and is provided with a foot or stand a¹. The
bobbin case or holder bis supported in a nearly vertical position in a chamber
or channel c formed in a bracket a³ cast upon or attached to the frame a of
the machine below the cloth plate d. The central pin or spindle b which
receives the bobbin e is fixed in the front end or point 6 of the case b; whose
other end 63 is left open to allow the said bobbin to be conveniently inserted
and removed. The bobbin e is preferably formed of a small metal tube with
a flange el at each end; the upper end of the bobbin e lies near the under
surface of the cloth plate d, and its thread is drawn through a number, of
small holes f. formed in the case or in a web or flange b' on the exterior of
the same. The case or holder b is formed with two lateral ribs or wings b' which
project into grooves c¹ formed in the side of the chamber c, and prevent: the
turning round of the said holder; the latter is held and kept from falling out of
the chamber c by the pressure of a spring 9 which is attached to the back of
the chamber. c, .and yields to allow the loops of needle thread to, pass up
between the case b and chamber c as each stitch is formed. The nose or
lower end 6 of the case or holder is pointed and curved outward to facilitate
the passing of the thread loops over the same. The vibrating hook which
brings down these loops is formed and arranged to vibrate across the front of
the case b; the outer end of this hook is formed with a triangular piece h
which is curved laterally, as shown in Figure 4, to correspond with the shape
of the point 62 of the bobbin case b.to allow the said hook to work in close
proximity to the same. The extremity of the hook h is bent down outside
this triangular piece h¹,. and forms a guard to prevent the slipping of the
thread from the book...The loop of needle thread when caught by the book h

page_text: lies in the notches or recesses hand behind the curved triangular piece.h¹,
and a space is left between the thread and the back of the latter, as shown in
Figure 4, wherein the point 62 of the bobbin case benters as the hook h
moves upward. A lever i with elastic arms 1, 2, preferably formed of steel
wire, is pivoted to the frame a in front of the needle barj; one arm of this
lever is formed with an eye k, through which the needle thread passes, the
same thread being alsó conducted through two fixed eyes or guides 1; the
other arm of the said lever is curved or bowed in its central portion, and
is arranged to be acted upon by a pin or stud m projecting from the needle
bar or part attached to the same; this stud m strikes the curved lever arm i
at both its upward and downward stroke, and when passing over the straight
portion of the said arm keeps the lever back with the proper tension upon
the thread. This lever is so arranged in relation to the other parts of the
mechanism as to be drawn back at the end of the upward stroke of the pro-
jecting stud m, and pull the thread loop upward as the same is passed by the
vibrating hook h over the point 62 of the bobbin case b. The action of the
projecting stud or pin m' upon the elastic lever i at the end of its downward
stroke also causes the latter again to tighten the thread loop as it is drawn
behind the bobbin case: band to slacken the needle thread in time to allow a
fresh loop to be caught upon the vibrating hook h.
double-armed lever i a bent arm 2*, Figure 6, may be
is fitted to vibrate upon its fulcrum j* by means of the pin m. When the
said pin rises above the bend of the arm * the latter is drawn forward and
slackens the needle thread, and is drawn back to tighten the same as the said
pin moves downward over the straight portion of the said arm. The feed bar n
is arranged in front of the vibrating hook h, the cams o, o¹, for operating the
said bar being fixed on the end of the lower rocking shaft p. The feed bar n is
so formed with the teeth n which act on the cloth between the fulcrum g of the
said bar and the cams o, o', for operating the same. By this means the friction
upon the lifting cam o¹ and consequent wearing away of the surface is greatly
reduced. The curved end of the feed barn is provided with two jaws n¹, n²,
for the cam o to act upon in imparting the required endwise movement.to
the said bar while it is lifted by the other cam o¹. The length of feed is
through the jaw n of
preferably regulated by a screw n³ which projects
Instead of the elastic
employed, which arm
the feed barn; the latter is formed at its other end with a. broad flat
piece or web n, which is fitted to
the under side of the cloth plate d.
which the barn_vibrates, and a springs attached to the cloth plate d is
slide through a guider attached to
This guide forms the fulcrum. upon

page_text: arranged to act with just sufficient pressure upon the barn to keep the
surface of the part n³ of the said bar properly in contact with the cam o'. The
rocking shaft t which operates the needle bar j is supported in suitable
bearings as attached to or formed in the upper part of the frame a; an arm u
on the front end of this shaft works in a groove v¹ formed in a plate v attached
to the said bar, and imparts thereto the required reciprocating motion. The
rear end of the shaft t is provided with another arm w which by preference
carries a friction roller w¹ arranged to run in a cam groove x¹ formed in the
driving wheel x; this groove may be formed to produce two or more recipro-
cations of the needle to one revolution of the said wheel. The shaft p for
operating the feed motion is carried in bearings a* attached to the lower part
of the frame a, and the arm p³, whereby this shaft is connected to the upper
shaft t, is fixed on its rear end in a convenient position to be taken hold of
by the rod t which connects the two arms p³ and w.. The holes 1, 2, 3, 4, in
the presser bar z are arranged one above the other, and when the adjustable
pin is inserted into either of these holes the spring bearing on the said
pin and upon the upper part of the frame a causes the presser foot z* to exert
a pressure upon the cloth proportionate to the distance of the hole from the
upper end of the spring. The presser bar z is preferably provided with a
pin or feather which projects into a groove in the bearing of the said bar
and prevents its turning round. The bar is supported when raised by a
which fits the upper end of the, bar, and is provided with a
pin arranged to drop into a hole when the bar is down, the said collar being
turned round on the bar when the latter is to be adjusted. The grooves z
in the presser foot or the projections thereon are preferably made V-shaped,
and the flange of the hemmer or other device to be attached to the said foot is
made of corresponding form. These.grooves or projections may extend entirely
or partially from end to end of the foot. The flange of the hemmer.or.other.
device is preferably formed of sheet .brass, steel, or other suitable metal, with
its sides bent or otherwise adapted to the shape of the presser foot. The
flange and foot are fitted together in such manner that the former will readily
slide endwise on the said foot, whereon it can be further secured by screws if
desired.
movable collar
The device, Figure 5, for filling the bobbin is arranged when in use at the
rear of the machine. The wheel B on the adjustable spindle C may be formed
with teeth corresponding with other teeth on the driving wheel x, or may be
furnished with an india-rubber.band or ring. B" and driven by friction.. :When
this friction ring is employed I arrange the same to run in contact with the

page_text: side of the rim of the wheel a, which then not only rotates the spindle C, but
also serves to press the said spindle forward to hold the bobbin. The spindle C
is supported in a bearing D secured to the foot or base of the frame, and is
formed with a concave centre C¹ to receive the end of the bobbin. When the
spindle C is driven by a toothed wheel the said spindle is caused to hold the
bobbin while the same is being filled by the pressure of a coiled spring sur-
rounding the said spindle; but when the wheel B is provided with the friction
ring B¹ arranged at the side of the wheel x, as above described, this spring
will not be necessary..
Having thus fully described the said improvements, and shown. how the
same may be conveniently and advantageously carried into practice, I
claim,―
.
First. Carrying the under thread of a sewing machine in a device con-
structed substantially like the ordinary shuttle employed in such machines,
but which remains. stationary while the loops of needle thread are drawn,
over it.
Second. The stationary holder 6 for carrying the under thread spool 1.or
bobbin constructed with the pin 6 and with the: ribs. or wings 65, substantially
as.and for the purposes set forth.
Third. Supporting the said stationary case or holder
means of a spring
in the chamber c in such a manner as to allow the loops.of needle thread to
pass behind the said holder, substantially as set forth.
Fourth. The vibrating hook h constructed and arranged to operate in
combination with. the stationary holder b, substantially as and for the purpose
set forth.
Fifth. The stationary holder vibrating hook h, and lever i, or equivalent
device, combined and operating together, substantially as and for the purpose
set forth.
Sixth. The holder b, vibrating hook h, lever i, and feed bar n, combined
and operating together, substantially as and for the purposes set forth.
Seventb. The feed barn with teeth n* between its vibrating end and fulcrum
or support, substantially as and for the purpose set forth.
Eighth. The combination of a stationary holder, reciprocating needle, and
vibrating hook for effecting the required combination of the two threads of a
"lock stitch" sewing machine, with suitable feeding and taking up devices,
and with mechanism whereby the required motion is given at the proper time
to each of these parts, substantially as set forth.
Ninth. Regulating the pressure of the spring 22 by changing the pin 2¹
Я
3

page_text: from one to another of the holes formed in the presser bar z, substantially as
set forth.
Tenth. Forming the presser foot z* with grooves 27, or with V-shaped or
other suitable projections on the sides, substantially as and for the purpose
set forth.
Eleventh. The device for filling the bobbin constructed and arranged to
operate in combination with the wheel x, substantially as set forth.
In witness whereof, I, the said Thomas Bletcher, have hereunto set my
hand and seal, this Eighteenth day of March, in the year of our Lord
One thousand eight hundred and sixty-eight.
THOMAS BLETCHER. (L.S.)