IMPROVEMENTS IN SEWING MACHINERY, MORE PARTICULARLY APPLICABLE TO THE PRODUCTION OF FRENCH VEIN OR HEM STITCH
Year: 1872

page_text: DISCLAIMER AND MEMORANDUM OF ALTERATION as proposed to be
entered by the said Joseph Buchanan Robertson, pursuant to the
Statutes in that case made and provided.
WHEREAS Her Majesty Queen Victoria, by Her Letters Patent,
under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the 30th day of March, One
thousand eight hundred and seventy-two, did give and grant unto me,
the said Joseph Buchanan Robertson, my executors, administrators, and
assigns, the sole privilege for the term of fourteen years thence next
ensuing of making, using, exercising, and vending, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and the Isle
of Man, the said Invention of "IMPROVEMENTS IN SEWING MACHINERY, MORE
PARTICULARLY APPLICABLE TO THE PRODUCTION OF FRENCH VEIN OR HEM STITCH:"

page_text: And whereas in pursuance of a proviso in the said Letters Patent
contained I, the said Joseph Buchanan Robertson, did, within six
calendar months next after the date of the said Letters Patent, cause a
Specification or instrument in writing under my hand and seal, pur-
porting to describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, to be duly filed in the
Great Seal Patent Office:
And whereas since the filing of the said Specification I, the said
Joseph Buchanan Robertson, have discovered that part of the said In-
vention as described in the said Specification may be objected to on the
ground that as described and claimed it was not new, in consequence
thereof I hereby disclaim and alter parts of the said Specification and
claiming clauses in manner following, that is to say :—
"
Referring to the Queen's Printers' copy of the said Specification I
omit the passage commencing in page 4, line 34, with the words "One
part," and concluding with the words "fabric only," in page 5, line 18.
In page 5, line 19, I omit the words "Another part of," and the word
"present." I omit the passage commencing in page 6, at line 17, with
the words "The feed;" and concluding with the words "the fabric,'
in page 6, line 28. I omit the passage commencing in page 9, line 1,
with the words "It is obvious," and concluding with the words "the
fabric," in page 9, line 9. In page 9, line 13, after the word "stitch"
I insert the following words, "nor do I claim the arranging of all the
cams on one shaft for sewing machines generally." I omit the first
claim occupying occupying lines 14 to 17 inclusive of page 9. In line 18
of page 9 for the word "Second" I substitute "First"; and in line 22
of page 9 for the word " Third" I substitute "Second," and the said
Specification when disclaimed and altered will read as follows:-
-
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
BUCHANAN ROBERTSON, of Lurgan, in the County of Armagh, Ireland,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of March, in the year
of our Lord One thousand 'eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Joseph Buchanan Robertson,
Her special licence that I, the said Joseph Buchanan Robertson, mý.

page_text: executors, administrators, and assigns, or such others as I, the said
Joseph Buchanan Robertson, 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 use, exercise, and vend, within the United King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN SEWING MACHINERY, MORE Par-
TICULARLY APPLICABLE TO THE PRODUCTION OF FRENCH VEIN OR HEM STITCH,".
upon the condition (amongst others) that I, the said Joseph Buchanan
Robertson, 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 Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Joseph Buchanan Robertson, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, reference being had to
the accompanying Sheet of Drawings, and to the figures and letters
marked thereon, that is to say :-
'
My Invention relates to the production by sewing machinery of an
improved stitch, resembling that commonly known as French vein or
hem stitch, and to the arrangement and construction of sewing.
mechanism for that purpose. The improved stitch is produced by
combining in one series two lateral movements and three vertical strokes
of the needle with two forward feeds and one backward feed of the
fabric, while the shuttle makes three ordinary strokes in the following
manner: The needle makes the first down stroke, and in this case it
is made to descend farther than in the other strokes of the series, so that
its taper swells the hole, the shuttle then passes through the loop of its
thread, when the needle rises the fabric is fed forward the distance of
one stitch, the needle descends to make its second stroke a little to one
side of the general line of the stitch, so as to pass through the fold or
hem and the shuttle again passes through the loop of its thread, when
the needle rises the fabric is again fed one stitch forward, the needle
descends for the third stroke in the line of the first stroke, its loop is .
again passed through by the shuttle, and when the needle rises the
?

page_text: fabric is fed one stitch back, and the needle descends in the line of the
.
made
^
stitch into the hole which was at the third stroke of the preceeding
series, and this new stroke is the first of the succeeding series.
The order of movements above described has already been adopted in
⚫ the
sewing machines adapted to the production of A French vein or hem
stitch, and it is therefore to be understood that no claim is now made for
such order. The feature of novelty in this case is the swelling of the
hole as described with reference to the first stroke of the series, which
gives an improved appearance to the work.
In the mechanism for producing the stitches as described above I
employ cams on a revolving shaft, connected by levers and rods to the
moving parts in the following manner:-For working the needle I
employ a cam, which gives in one revolution three vertical strokes to
the needle, one of those strokes being greater than the other two, so as
to make the needle descend farther and swell the hole, as above
described; I also employ another cam for giving the needle its lateral
movements for two of its three vertical strokes; another cam works the
shuttle, giving it three strokes during each revolution; a pair of cams or
a grooved cam works the feed gear, giving two forward feeds and one
backward feed during each revolution. By this arrangement of cams for
working the various parts of the mechanism, as above described, I am
enabled to dispense entirely with gearing, such as has been used in
machinery for producing stitching of this kind, and by fixing all the A
in order on one driving shaft I secure great simplicity of construction
and action.
cams
It will be understood that although I have described cams suited for
three stitches during each revolution, they might be made to perform
six or any multiple of three, the order of each series of three being
maintained as I have described it.

page_text: Figures 4, 5, and 6 shew developed plans to a larger scale of the
several cams actuating the different parts of the machine.
:
Upon the driving shaft A of the machine is fixed a grooved cam B, in
which works a pin or truck on the end C¹ of the bent lever C actuating
the needle bar; this lever is pivotted at c to the fixed arm D. The
groove of the cam B, which is shewn developed at Fig. 4, is so formed
as to impart three vertical strokes to the needle during one revolution of
the cam, and to cause the needle to descend farther in one of the strokes
than in the other two, as shewn at X. Against the fixed arm D works
the sliding arm E carrying the needle slide and bar. This arm is made.
to impart the requisite lateral motion to the needle for producing the
hem stitch by means of a face cam F formed on the side of the cam B.
The arm E is for this purpose extended below the bed plate, where it is
provided with a boss E¹ fixed by means of a set screw to a sliding bar E³.
The boss E¹ carries a finger E³ having an adjusting screw which is made
to bear against the cam F by means of the spring Et, so that the
projecting part of the cam forces the finger E³, and with it the sliding
arm and needle backwards, so as to impart to the needle its backward
lateral motion, while the receding part of the cam allows the spring E*..
to impart to the sliding arm its forward lateral motion. The cam F is so
formed relatively to the cam B as to cause the needle to be in the
forward lateral position during two of the strokes of the needle, and in
the backward lateral position during the third stroke of the needle, as
will be seen from the developed plan at Fig. 4.
It will be understood that a grooved cam imparting a positive motion
to the sliding arm might be employed in place of the face cam F and
spring E. Upon the shaft A is also fixed a grooved cam G operating in
combination with a stud or projection H on the cam B for actuating the
feed mechanism arranged in the following manner :-The presser foot I
is fixed to a bent arm I¹ pivotted at i to a boss J rocking on a pin j.
The extremity I³ of the arm I¹ is pressed by a spring I³ towards the face
of the cam B, by which pressure the foot I is made to press the fabric
against the sliding feed plate K during two forward motions and one.
backward motion of the feed, but during the second backward motion of.
the feed mechanism the foot I is raised up from the feed plate K by the
projection H on the cam B pressing the end I of the arm 1¹ outwards
against the action of the spring I³. The boss J forms part of a bell-
crank lever J', J, of which the part J¹ is slotted, and is connected to

page_text: another slotted lever L by an adjustable pin L', while the arm J² is con-
nected to the feed plate K. The lever L is pivotted on a pin 7, and at
its extremity it has a pin or truck g taking into the grooved cam G. By
this cam a rocking motion is imparted to the lever L, and the latter
imparts its rocking motion to the bell-crank lever J¹, J', the presser
arm I being attached to the boss J of the lever J', J', while the feed
plate K is connected to the arm J2 of this lever, it will be seen that by
the rocking motion of the lever the desired forward and backward feed
motions will be imparted simultaneously and equally to the presser arm
and the feed plate, thus causing them while grasping the fabric to feed
the same forwards and backwards as required.
The cam G is so formed, as shewn developed at Fig. 5, that during
one revolution (and consequently during three strokes of the needle) it
imparts two forward motions and two backward motions to the presser
and feed plate.
By adjusting the pin L' in the slots of the levers L and J¹ so as to
vary its distance from the respective fulcra of the two levers it will be
seen that the extent of the rocking motion of the lever J¹, J³, and con-
sequently the extent of the feed motion, can be varied. Upon the
shaft A is fixed furthermore a grooved cam M for imparting the requisite
motion to the shuttle. A lever N pivotted at n has a pin or truck n²
taking into the groove of the cam, and is connected at its extremity by
means of a link N¹ to the shuttle driver. The cam M is so formed, as
shewn developed at Fig. 6, as to impart to the shuttle three double
strokes during one revolution.
From the above-described construction of the machine it will be seen
that the whole of the before-described movements are effected by means
of the several cams on the shaft A. By properly setting these cams on
the shaft the movements are effected in such order as to produce the
French vein or hem stitch above described. The curvature of the cam B
may be made to correspond with that at X at another of its convolutions,
so that the needle may be made to descend twice during a revolution to
a greater depth through the fabric and so to swell the hole in it as above
described, such descent being in each case through the shire.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I would have it understood that I
do not claim the order of stitches herein described for producing hem

page_text: stitch, nor do I claim the arranging of all the cams on one shaft for
sewing machines generally, but I do claim,—
First. The use for hem stitching machines of cams on one driving
shaft, whereby the whole series of movements for three stitches are
produced in one revolution, thus dispensing with toothed gearing, sub-
stantially as herein described.
Second. The use in such hem stitching machines of a needle cam so
constructed as to make the needle descend farther through the fabric in
some stitches than in others, and so to swell certain of the holes therein,
substantially as herein described.
In witness whereof, I, the said Joseph Buchanan Robertson, have
hereunto set my hand and seal, this Twenty-sixth day of
September, in the year of our Lord One thousand eight hundred
and seventy-two.
JOSEPH B. ROBERTSON. (L.S.)
In witness whereof, I, the said Joseph Buchanan Robertson, have
hereunto set my hand and seal, this Twentieth day of November,
in the year of our Lord One thousand eight hundred and seventy-
five.
I hereby grant my fiat, giving leave to the above-named Joseph
Buchanan Robertson, to file in the Great Seal Patent Office, with the
Specification to which the same relates, the above-written Disclaimer
and Memorandum of Alteration, upon the condition that the said Joseph
Buchanan Robertson shall take no legal proceedings under the said
Patent, No. 942 of 1872, in respect of eighty machines already made or
in process of manufacture by John Hamilton, of Dromore, in the
County Down, Ireland. Costs of the opposition to be paid by the
applicant.

page_text: LETTERS PATENT to Joseph Buchanan Robertson, of Lurgan, in the
County of Armagh, Ireland, for the Invention of "IMPROVEMENTS IN
SEWING MACHINERY, MORE PARTICULARLY APPLICABLE TO THE PRODUCTION OF
FRENCH VEIN OR HEM STITCH."
Sealed the 14th June 1872, and dated the 30th March 1872.
PROVISIONAL SPECIFICATION left by the said Joseph Buchanan
Robertson at the Office of the Commissioners of Patents, with
his Petition, on the 30th March 1872.
:
I, JOSEPH BUCHANAN ROBERTSON, of Lurgan, in the County of
Armagh, Ireland, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SEWING MACHINERY, MORE PARTICULARLY APPLICABLE TO
THE PRODUCTION OF FRENCH VEIN OR HEM STITCH," to be as follows:-
One part of my present Invention relates to the feed gear of sewing
machines. In the machines generally known and used the fabric is fed
by means of a moving part or piece usually serrated, which acting on
one side of the fabric presses it against a smooth surface on the other

page_text: side of the fabric, and the moving piece advancing carries the fabric with
it, causing it to slide over the smooth surface against which it is pressed.
According to my present Invention I cause the fabric to be grasped by
spring pressure between two moving pieces, which may be smooth or
serrated, and these pieces are so connected together that they move simul-
taneously and equally, carrying with them the fabric grasped between
them. During their return stroke, when the fabric has to remain at
rest, the pinch of the two pieces is releived so that they return without
carrying the fabric with them. The movements of these feeding pieces
may be effected by means of cams or other known mechanism, and may
be adjusted to give a longer or shorter stitch by altering the leverage of
the parts acting on them in any known manner. This mode of feeding
is applicable to sewing machines generally, and presents this advantage,
that when there is more than one thickness of fabric to be stitched
through the whole is carried on together without the puckering or the
stretching of one fabric beyond another, which sometimes occurs when
the feed is operated by the movement of a piece acting on one side of the
fabric only.
Another part of my present Invention relates to the production by
sewing machinery of an improved stitch, resembling that commonly
known as French vein or hem stitch, and to the arrangement and con-
struction of sewing mechanism for that purpose. The improved stitch is
produced by combining in one series two lateral movements and three
vertical strokes of the needle, with two forward feeds and one backward
feed of the fabric, while the shuttle makes three ordinary strokes in the
following manner :—The needle makes the first down stroke, and in this
case it is made to descend farther than in the other strokes of the series,
so that its taper swells the hole, the shuttle then passes through the
loop of its thread, when the needle rises; the fabric is fed forward the
distance of one stitch; the needle descends to make its second stroke a
little to one side of the general line of the stitch so as to pass through
the fold or hem, and the shuttle again passes through the loop of its
thread;
when the needle rises, the fabric is again fed one stitch forward,
the needle descends for the third stroke in the line of the first stroke, its
loop is again passed through by the shuttle, and when the needle rises
the fabric is feed one stitch back and the needle descends in the line
of the stitch into the hole which was made at the third stroke of the
preceeding series, and this new stroke is the first of the succeeding series.

page_text: The order of movements above described has already been adopted in
sewing machines adapted to the production of the French vein or hem
stitch, and it is therefore to be understood that no claim is now made for
such order. The feature of novelty in this case is the swelling of the
hole as described with reference to the first stroke of the series, which
gives an improved appearance to the work.
In the mechanism for producing the stitches, as described above, I
employ cams on a revolving shaft, connected by levers and rods to the
moving parts in the following manner:-For working the needle I
employ a cam which gives in one revolution three vertical strokes to the
needle, one of those strokes being greater than the other two, so as to
make the needle descend farther and swell the hole, as above described.
I also employ another cam for giving the needle its lateral movements
for two of its three vertical strokes. Another cam works the shuttle
giving it three strokes during each revolution. A pair of cams work the
feed gear, giving two forward feeds and one backward feed during each
revolution. The feed may either be of the kind known as the "four-
motion feed," or it may be of the kind which I have described above. In
the latter case one of the cams moves the foot above the fabric and a
sliding piece below it to and fro in the direction of the feed, both the
foot and the sliding piece being attached to arms from one vertical
rocking shaft so that they move uniformly together. They are pressed
together by a spring acting on the arm which carries the foot so as to
press it down on the fabric. A cam or wiper acts on this arm so as
once in
every revolution to raise the foot and so relieve the grasp of the
fabric during one of the back strokes of the feed so as to enable the grasp
to close again on a fresh part of the fabric. By this arrangement of cams
for working the various parts of the mechanism, as above described, I
am enabled to despense entirely with gearing such as has been used in
machinery for producing stitching of this kind, and by fixing all the
cams in order on one driving shaft I secure great simplicity of construc-
tion and action.
It will be understood that although I have described cams suited
for three stitches during each revolution, they might be made to perform
six or any multiple of three, the order of each series of three being
maintained as I have described it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Buchanan Robertson in the Great Seal
Patent Office on the 28th September 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
BUCHANAN ROBERTSON, of Lurgan, in the County of Armagh, Ireland,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of March, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Joseph Buchanan Robertson, Her special
licence that I, the said Joseph Buchanan Robertson, my executors,
administrators, and assigns, or such others as I, the said Joseph
Buchanan Robertson, 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 "IMPROVEMENTS IN SEWING MACHINERY, MORE PARTICULARLY
APPLICABLE TO THE PRODUCTION OF FRENCH VEIN OR HEM STITCH," upon
the condition (amongst others) that I, the said Joseph Buchanan
Robertson, 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 Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
i
NOW KNOW YE, that I, the said Joseph Buchanan Robertson, 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
accompanying Sheet of Drawings, and to the figures and letters marked
thereon, that is to say :-
One part of my present Invention relates to the feed gear of sewing
machines. In the machines generally known and used the fabric is fed
by means of a moving part or piece usually serrated, which, acting on
one side of the fabric presses it against a smooth surface on the other

page_text: side of the fabric and the moving piece advancing carries the fabric
with it, causing it to slide over the smooth surface, against which it is
pressed. According to my present Invention I cause the fabric to be
grasped by spring pressure between two moving pieces, which may be
smooth or serrated, and these pieces are so connected together that they
move simultaneously and equally, carrying with them the fabric grasped
between them. During their return stroke, when the fabric has to
remain at rest, the pinch of the two pieces is relieved, so that they
return without carrying the fabric with them. The movements of these
feeding pieces may be effected by means of cams or other known
mechanism, and may be adjusted to give a longer or shorter stitch by
altering the leverage of the parts acting on them in any known manner.
This mode of feeding is applicable to sewing machines generally, and
presents this advantage, that when there is more than one thickness of.
fabric to be stitched through, the whole is carried on together without
the puckering or the stretching of one fabric beyond another, which:
sometimes occurs when the feed is operated by the movement of a piece
acting on one side of the fabric only.
Another part of my present Invention relates to the production by
sewing machinery of an improved stitch resembling that commonly.
known as French vein or hem stitch, and to the arrangement and con-
struction of sewing mechanism for that purpose. The improved stitch
is produced by combining in one series two lateral movements and three
vertical strokes of the needle with two forward feeds and one backward
feed of the fabric while the shuttle makes three ordinary strokes in the
following manner :-The needle makes the first down stroke, and in this
case it is made to descend farther than in the other strokes of the series,
so that its taper swells the hole, the shuttle then passes through the
loop of its thread; when the needle rises the fabric is fed forward the
distance of one stitch, the needle descends to make its second stroke a
little to one side of the general line of the stitch, so as to pass through
the fold or hem, and the shuttle again passes through the loop of its
thread; when the needle rises the fabric is again fed one stitch forward,
the needle descends for the third stroke in the line of the first stroke,
its loop is again passed through by the shuttle, and when the needle
rises the fabric is fed one stitch back and the needle descends in the
line of the stitch into the hole which was made at the third stroke of
the preceding series, and this new stroke is the first of the succeeding
series.
·

page_text: The order of movements above described has already been adopted in
sewing machines adapted to the production of the French vein or hem
stitch, and it is therefore to be understood that no claim is now made
for such order. The feature of novelty in this case is the swelling of the
hole, as described with reference to the first stroke of the series, which
gives an improved appearance to the work.
In the mechanism for producing the stitches as described above I
employ cams on a revolving shaft connected by levers and rods to the
moving parts in the following manner:-For working the needle I
employ a cam which gives in one revolution three vertical strokes to the
needle, one of those strokes being greater than the other two, so as to
make the needle descend farther and swell the hole, as above described.
I also employ another cam for giving the needle its lateral movements
for two of its three vertical strokes. Another cam works the shuttle,
giving it three strokes during each revolution. A pair of cams or a
grooved cam works the feed gear, giving two forward feeds and one
backward feed during each revolution. The feed may either be of the
kind known as the "four-motion feed," or it may be of the kind
which I have described above. In the latter case one of the cams moves
the foot above the fabric and a sliding piece below it to and fro in the
direction of the feed, both the foot and the sliding piece being attached
to arms from one vertical rocking shaft or socket joint, or other equi-
valent, so that they move uniformly together. They are pressed together
by a spring acting on the arm, which carries the foot so as to press it
down on the fabric. A cam or wiper acts on this arm so as once in
every revolution to raise the foot and so relieve the grasp of the fabric
during one of the back strokes of the feed, so as to enable the grasp to
close again on a fresh part of the fabric. By this arrangement of cams
for working the various parts of the mechanism as above described I am
enabled to dispense entirely with gearing such as has been used in
machinery for producing stitching of this kind, and by fixing all the
cams in order on one driving shaft I secure great simplicity of con-
struction and action.

page_text: Fig. 1 shews a side view of a sewing machine with my before-described
improvements applied thereto; Fig. 2 shews a plan with the bed plate
partly removed, shewing the mechanism beneath the same; and Fig. 3
shews a front view partly in section. Figures 4, 5, and 6 shew developed
plans to a larger scale of the several cams actuating the different parts of
the machine. Upon the driving shaft A of the machine is fixed a grooved
cam B, in which works a pin or truck on the end C¹ of the bent lever O
actuating the needle bar; this lever is pivotted at c to the fixed arm D.
The groove of the cam B, which is shewn developed at Fig. 4, is so formed
as to impart three vertical strokes to the needle during one revolution of
the cam, and to cause the needle to descend farther in one of the strokes
than in the other two, as shewn at X. Against the fixed arm D works
the sliding arm E carrying the needle slide and bar; this arm is made
to impart the requisite lateral motion to the needle for producing the
hem stitch, by means of a face cam F formed on the side of the cam B;
the arm E is for this purpose extended below the bed plate where it is
provided with a boss E¹ fixed by means of a set screw to a sliding bar E³.
The boss E¹ carries a finger E³, having an adjusting screw which is made
to bear against the cam F by means of the spring E, so that the pro-
jecting part of the cam forces the finger E³, and with it the sliding arm
and needle backwards, so as to impart to the needle its backward lateral
motion, while the receding part of the cam allows the spring E* to impart
to the sliding arm its forward lateral motion. The cam F is so formed
relatively to the cam B, as to cause the needle to be in the forward
lateral position during two of the strokes of the needle, and in the
backward lateral position during the third stroke of the needle, as
will be seen from the developed plan at Fig. 4. It will be under-
stood that a grooved cam imparting a positive motion to the sliding
arm might be employed in place of the face cam F and spring E*.
Upon the shaft A is also fixed a grooved cam G operating in combi-
nation with a stud or projection H on the cam B, for actuating the feed
mechanism arranged in the following manner :-The presser foot I is
fixed to a bent arm I', pivotted at i to a boss J rocking on a pin j. The
extremity I³ of the arm I' is pressed by a spring I' towards the face of
the cam B, by which pressure the foot I is made to press the fabric
against the sliding feed plate K during two forward motions, and one
backward motion of the feed, but during the second backward motion of

page_text: ,
the feed mechanism the foot I is raised up from the feed plate K by the
projection H on the cam B pressing the end I of the arm I¹ outwards
against the action of the spring Is. The boss J forms part of a bell-
crank lever J, J', of which the part J¹ is slotted and is connected to
another slotted lever L by an adjustable pin L', while the arm J³ is
connected to the feed plate K. The lever L is pivotted on a pin l, and
at its extremity it has a pin or truck g taking into the grooved cam G.
By this cam a rocking motion is imparted to the lever L, and the latter
imparts its rocking motion to the bell-crank lever J¹, J². The presser
arm I being attached to the boss J of the lever J, J, while the feed
plate K is connected to the arm J' of this lever, it will be seen that by
the rocking motion of the lever the desired forward and backward feed
motions will be imparted simultaneously and equally to the presser arm
and the feed plate, thus causing them, while grasping the fabric, to
feed the same forwards and backwards as required. The cam G is
BO formed, as shewn developed at Fig. 5, that during one revolution
(and consequently during three strokes of the needle) it imparts two
forward motions and two backward motions to the presser and feed plate.
By adjusting the pin L' in the slots of the levers L and J¹, so as to
vary its distance from the respective fulcra of the two levers it
will be seen that the extent of the rocking motion of the lever J¹, J³,
and consequently the extent of the feed motion can be varied.
Upon the shaft A is fixed furthermore a grooved cam M for imparting
the requisite motion to the shuttle. A lever N pivotted at n, has a pin
or truck n¹ taking into the groove of the cam, and is connected at its
extremity by means of a link N¹ to the shuttle driver. The cam M is
so formed, as shewn developed at Fig. 6, as to impart to the shuttle
three double strokes during one revolution.
From the above-described construction of the machine it will be seen
that the whole of the before-described movements are effected by means
of the several cams on the shaft A. By properly setting these cams on
the shaft, the movements are effected in such order as to produce the
French vein or hem stitch above described. The curvature of the
cam B may be made to correspond with that at X at another of its con-
volutions, so that the needle may be made to descend twice during a
revolution to a greater depth through the fabric, and so to swell the
hole in it, as above described, such descent being in each case through
the shire

page_text: It is obvious that feed apparatus such as has been described above
may be employed in other sewing machines for the purpose of effecting
the feed of the fabric by grasping it between the presser foot and the
feed slide during their forward movement, and releasing it from the
grasp during their backward movement, as herein described. When
such a mode of feeding is employed the serrating of the feed slide or
presser foot may be dispensed with, as the grasp of the fabric between
them during their simultaneous movement is sufficient to effect the
required movement of the fabric.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I would have it understood that
I do not claim the order of stitches herein described for producing hem
stitch, but I do claim,―
First. The mode, substantially as herein described, of feeding the
fabric in sewing machines, by grasping it between the presser foot and
the feed slide, and causing them to move simultaneously the required
length of stitch.
.Second. The use for hem stitching machines of cams on one driving
shaft, whereby the whole series of movements for three stitches are
produced in one revolution, thus dispensing with toothed gearing, sub-
stantially as herein described.
Third. The use in such hem stitching machines of a needle cam so
constructed as to make the needle descend farther through the fabric
in some stitches than in others, and so to swell certain of the holes
therein, substantially as herein described.
In witness whereof, I, the said Joseph Buchanan Robertson, have
hereunto set my hand and seal, this Twenty-sixth day of Septem-
ber, in the year of our Lord One thousand eight hundred and
JOSEPH B. ROBERTSON. (L.S.)