IMPROVEMENTS IN BUTTON-HOLE ATTACHMENTS FOR SEWING MACHINES
Year: 1877

page_text: LETTERS PATENT to William McIntyre Cranston, of Worship Street, Finsbury,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
BUTTON-HOLE ATTACHMENTS FOR SEWING MACHINES." A communication
from abroad by Willard Gay, of Troy, New York, United States of America.
Sealed the 8th March 1878, and dated the 12th September 1877.
PROVISIONAL SPECIFICATION left by the said William McIntyre Cranston
at the Office of the Commissioners of Patents on the 12th September 1877.
WILLIAM MCINTYRE CRANSTON, of Worship Street, Finsbury, in the County of
Middlesex. " IMPROVEMENTS IN BUTTON-HOLE ATTACHMENTS FOR SEWING
MACHINES," A communication from abroad by Willard Gay, of Troy, New York,
United States of America.
The object of this Invention is effected by fitting on or to the bottom shaft of a
sewing machine a roller with a double groove merging into a single one, by
the removal of part of the division of the two grooves and thinning off the edges, in
order that a double convex-shaped piece of metal may pass from groove to groove
in regular succession on the rotation of the roller by the ordinary working
mechanism.
The double convex-shaped piece of metal is by link or lever appliances caused to
work the ordinary presser or feed foot for general sewing; but for button-hole work
a base plate is affixed to the back table. The double convex plate is pivotted to a
lever pinned at its opposite end to the base plate for the lever to move to and fro
from that end. This lever is slotted, and one end of a connecting link is
fitted in it, the other end of the link being fitted in a slot of a similar lever,
which is pinned to the plate at the end opposite to that of the first-mentioned
lever.
The second lever has a pin in an independent slot, the pin taking into a
plate capable of sliding to and fro between guide cheeks upon the base plate.
The sliding plate has cheeks within which a leg of a 1 shaped plate is arranged.
.

page_text: The head of this T shaped plate is slotted, and a slider works in it; this slider is
in part with a combined holder and presser plate between which the fabric is held
firmly during the operation of sewing the button hole.
The holder and presser plates each have a slot of the full length of the largest
button hole required. The presser plate has a cam and hand lever by which the
fabric can be released and secured as required.
The second named slider has a link affixed, whose opposite end is attached
to a crank pin, free to move in a slot cut across the face of a disc, which
receives a horizontal circular motion on its own centre under the action of push
pauls.
The crank pin is adjustable in the slot of the disc, and as the button hole to be
sewn is a long or a short one, so this plate is set farther from or nearer to the centre
and there fixed by a tightening nut.
The push pawls take into ratchet teeth on the periphery of the disc, and are
governed by a lever, a portion of which is slotted for the adjustment of a pin to
regulate the number of teeth over which the pauls shall pass before they re-engage
to push the disc on again.
The pin is adjustable in the slot by a micrometric screw passed into a stem of
a lever, whose lower part is V shaped and fitted in a slot of a moveable plate for the
purpose.
The under side of the slotted disc carries a cam working in a race having
two shaped projections in an enlargement of a pivotted lever. The opposite end
of this lever is pinned to a bracket by which the holder and presser plates and parts
, connected are thrown to one side for enabling the needle to pass through the fabric
on the other side of the button hole, after rounding the end or "stab" at the top
of it. The pin on which this lever oscillates is adjustable by a micrometric screw
to regulate the distance from the edge of the button hole the needle shall enter the
fabric.
The double-grooved roller firet mentioned causes the levers to move the fabric
holder and presser plate, with the plain slit or button hole within their grasp, to and
fro as the needle leaves the fabric and the slit alternately in its up strokes,
the parts just mentioned remaining at rest while the needle is passing into and out
of the fabric in making the stitch, the double convex plate then riding in one of
the grooves, both of which are concentric to the axis of the shaft. The shift
over of the mechanism taking place while the double convex plate is passing
from one groove to the other.
The ratchet wheel has two edges of different diameters, on opposite quarters of
each of which the teeth are cut for the pauls to take into in succession. The two
sets of teeth on one periphery carry the disc or slotted plate over the centres and
round the ends of the button hole; while those of the other edge carry the disc
round while the straight part of the button hole is being made.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William McIntyre Cranston in the Great Seal Patent Office on the
12th March 1878.
WILLIAM M'INTYRE CRANSTON, of Worship Street, Finsbury, in the County of
Middlesex. "IMPROVEMENTS IN BUTTON HOLE ATTACHMENTS FOR SEWING
MACHINES." (A communication from abroad by Willard Gay, of Troy, New York,
United States of America.)
The nature of this Invention consists in providing the feeding mechanism of a
button-hole attachment with certain adjustable and automatic devices for feeding
the button hole under the needle, so that it will be stitched entirely around
in a uniform manner, and the ends be stitched in a thorough and proper manner,
and without stopping the machine to re-adjust the fabric.
Also for commencing the stitching at any part of the button hole, which may
happen to be the most convenient.
Also in providing it with an equalising cloth clamp, which will secure the
cloth in proper position under the needle without regard to uniformity of
thickness.
Considerable difficulty has been experienced in the use of these attachments on
account of the delicate and complex mechanism and consequent liability to get
out of repair; also on account of the imperfect mechanism for feeding the button
hole entirely around under the needle in a suitable manner without stopping the
machine to adjust the goods before the button hole can be stitched complete,
and the necessity for commencing the stitch at some particular point of the button
hole.
Also for the reason that many important parts do not work automatically,
and therefore the advantages in point of speed are not sufficient to bring the attach-
ments into general use.
To obviate these as well as minor difficulties is the object of this Invention.
Figure 1 is a plan view of attachment, showing the parts above the bed plate
with a portion of the crank wheel broken away to show the feed wheels.
Figure 2 is a plan view of under side of attachment, with part of bed plate broken
away, showing more fully the fulcrum plate.
Figure 3 is a section through lines 1 and 2 of Figures 1 and 2, with the crank
wheel shown in elevation, and with part of feed wheel B" broken away to show
the shaft of the crank wheel more fully.
Figure 4 is a seotion through lines 3 and 4 of Figures 1 and 2.
Figure 5 is a front view of clamping device with lever down, showing by dotted
lines the position the clamp may occupy when the fabric underneath it is of
unequal thickness.
Figure 6 is a front view of clamping device, with lever up, with clamp U moved
sideways upon its loose bearing.
Figure 7 is a view of crank wheel and feeding wheels inverted to show the position
of the feed wheels upon the crank wheel.
Figure 8 is a view of the different holes made by the needle in working a button
hole.
A is the bed plate of the attachment to which the several parts are attached, and
is secured to the bed plate of the sewing machine in such manner as the construction
of the sewing machine will allow.
B is a vibrating lever, pivoted at one end c to the bed plate, and having at
its opposite end wa cam follower, against which a switch cam upon the driving
shaft of the sewing machine works, thereby imparting a vibratory motion to the
lever, and through it to the various parts of the attachment.
While we prefer this mode of imparting motion to the attachment, there are some

page_text: sewing machines which from their peculiar construction will more advantageously
operate the attachment by some one of the other known methods.
C is a vibrating lever having its inner end pivoted by the bolt or screw z to the
bed plate, and also attached by a bolt or pin R through a slot near its inner end to
the sliding plate E, to which it imparts a reciprocating motion, being connected to
lever B by the adjustable connecting bar a. These two levers have longitudinal
slots into which the connecting bar a is adjustably secured by pins or bolts, or
nuts X and Y. As this bar is moved in the slots nearer to or further from the
sliding plate E, the width of throw or extent of motion of the plate E will be
increased or diminished, thereby increasing or diminishing the width of throw of
the cloth under the needle. The sliding plate E is gibbed in ways K, K, which are
cast on or secured to the bed plate, and receives its motion from the vibrations of
levers B and C, as described.
D is the change plate gibbed in ways a, a", which are secured to or cast on
plate E. This change plate D receives a reciprocating motion with its sliding plate.
Its position upon this plate E is changed by its attachment to one end of the knee
arm by the nut or screw a', the opposite end of the arm v being attached to the
cam lever u on the under side of the bed plate, as shown in Figures 2 and 4.
F is the feed bar gibbed in a slot on the change plate D, and is connected by
pitman G to the hub I on the crank wheel H, from which it receives a lateral
reciprocating motion while being carried longitudinally by the change plate. The
pitman G, above mentioned, is attached to the feed bar F by a screw or bolt p, and
at its opposite end is attached to the hub I, which is adjustably secured in a slot in
the crank wheel H. By the adjustment of this hub and pitman the feed bar and
its connecting mechanism are adjusted to the length of the button hole to be
worked. The nearer the hub I is adjusted to the axis of the crank wheel the
shorter will be the throw of the feed bar and the attached cloth clamp U, and the
shorter necessarily will be the lines of stitching. The crank wheel H, above men-
tioned, revolves on a shaft projecting through one end of the sliding plate E, as
shown in Figure 3, with which it receives a longitudinal reciprocating motion. It
gets a rotary motion as follows:-The lower half or part of this wheel has its cir-
cumference reduced to take the place or answer the purpose of one or more addi-
tional wheels or ellipses secured thereto (see A, B, Figures 1, 3, and 7), and for
convenience we will call such reduced circumference feed wheels or circles A"
and B. If these wheels are made circular, two of them will be required; if ellip-
tical, one will answer the purpose. When made in proper form these wheels are of
different diameters and have teeth upon their peripheries, only partly around them,
the remaining portions of their peripheries being blank. Into these teeth work the
feed dogs J, J", which are secured by the pin to the short arm of the feed
lever C and held into the teeth by springs 0', O". Feed lever O" is a slotted
lever pivoted near its inner end h to the bed plate. Into its slot is received
a pin n which is attached to one end of an adjustable arm j, the opposite end gl
being secured in the plate E and made adjustable therein by a thumbscrew M.
From this plate the lever C" gets a vibratory or swinging motion, and from thence
the feed dogs J and J¹¹ working in the feed teeth in the crank wheel H give such
crank wheel a rotary motion.
It is obvious that while the crank wheel may have a regular or uniform rotary
motion when the attachment is in operation, it will not give through the pitman G
a regular or uniform throw to the feed bar F when the hub I to which one end of
the pitman is attached is adjusted to any point beyond the centre of the crank
wheel, and that if adjusted to the centre of the crank wheel the feed bar would get
no throw, consequently the stitches would all be made in one place. If adjusted
beyond the centre of the wheel, and the wheel be made to revolve by a single dog
working into teeth set in one circle, the pitman G must give an irregular throw
to the feed bar F, a shorter throw as the pitinan approaches or comes parallel with
or over the slot in the crank wheel or over its centre. Consequently a greater
number of stitches will be made around the ends of the button hole than along its

page_text: sides, the ends being stitched around as the pitman passes over the centre of the
crank wheel
To obviate these difficulties, and to produce a sufficiently uniform stitch around
the ends of the button hole, we make these feed wheels or circles A", B, upon the
crank wheel, as described, each circle or feed wheel having a different diameter, as
shown in Figures 1, 3, and 7. The diameter of circle A is much greater than of
circle B¹¹. Upon these circles are toothed and blank spaces, the teeth upon one
circle being opposite the blank upon the other, each circle having two equal toothed
spaces and two equal blank spaces.
The dog works into the teeth upon circle A¹¹, and the dog J into the teeth
upon circle B. The toothed and blank spaces are so arranged upon these circles
or wheels than when the pitman G is about to pass and passes the centre of the
crank wheel, as above described, the dog J¹¹ falls into one of the toothed sections of
circle B, while the dog J' is sliding over a blank section upon circle A". After
passing either of these centres the dog J¹ drops into one of the toothed sections
upon circle A while dog J¹¹ is sliding over a blank section upon circle B¹. Circle Bu
being less in circumference and sufficiently less than the circumference of circle A¹¹,
a greater are on the crank wheel will be made to pass a point by the action of the
dog Jagainst the teeth of the smaller circle B", and just enough greater to
maintain a sufficiently equal and uniform throw of the feed bar F (the circles
having the proper circumference), thereby making the stitches in the ends of
the button hole sufficiently uniform with stitches in its sides. While this manner
of arranging these teeth upon the crank wheel is preferred it is obvious that
instead of two circles with teeth upon the crank wheel, a toothed ellipse and a
single dog might be made to produce a similar result if the ellipse be made
with great care and precision, and of the precise form required, and I do not
therefore limit my claim to any peculiar form of the device carrying these teeth,
but claim as this part of the Invention all arrangements of teeth upon a feed
driving device having for their object the production of a uniform throw of the feed
bar. The fineness of the stitch is regulated as follows:-M is a screw secured in a
sleeve on the sliding plate E, as shown in Figure 1, and projecting through and
working in one end g₁ of the connecting arm, where it is grooved into the plate E.
The opposite end of the arm j is held by a pin n¹ in a slot of the feed lever C. By
means of this screw the arm ; may be adjusted at any point in the slot of the feed
lever C¹¹ and the slot of the plate E, thereby changing in effect the length of the
long arm of the feed lever.
The dogs J and J" being pivoted to the short arm of the feed lever the
farther the arm j is moved from the fulcrum of this feed lever the less number
of teeth upon the circles A, B, will be taken by the dogs with each swing
of this feed lever, and the less speed given to the crank wheel H by each
swing of the feed lever, and consequently the finer or closer must be the stitches
around the button hole.
The mechanism for moving the change plate D, and cloth clamp and carrier
attached thereto, independently of the reciprocating motion received from the
sliding plate E for the purpose of carrying the unstitched side of the button
hole under the needle after one side has been stitched is as follows:-u is a cam
lever on the under side of the bed plate, having one end pivoted to the knee
arm v, which is secured to the change plate by screw or bolt a¹, and near its
centre adjustably attached through a slot therein by a screw x as its fulcrum
to fulcrum plate b¹, shown in Figure 2. The opposite end of the lever u is
spread out into a ring, having on its inner edges two projections S and S".
Within this ring is a cam u¹¹ attached to the lower end of the shaft of the crank
wheel H, projecting through the sliding plate E, and in such position that the cam u¹¹
will strike against one of the projections 811, s", as the crank wheel revolves, and by
means of the knee arm v, to which the opposite end of the cam lever is attached,
will at the right point move the change plate D and its attached cloth clamp so that
the unstitched side of the button hole will pass under the needle after one or both

page_text: ends have passed under the needle. This cam u¹¹ is of such shape and so accurately
adjusted that whatever position it occupies in the ring of the cam lever it will bear
against the two projections 81, 8, and thereby prevent any play or lost motion in
the cam lover. In place of the two projections in the ring of the cam lever u it is
obvious that a different form of projections, or even a square or parallellogram
in place of the ring and projections might be made to answer a similar purpose,
and I make no claim upon and do not limit myself to any peculiar shape of this
lever u, but claim a cam and lever movement, substantially as herein described, for
the purpose of operating the change plate.
When the connecting arm a is adjusted to regulate the depth of stitch it is of
course necessary to adjust the throw or extent of motion of the change plate, so
that the stitches will be made at a uniform distance from the slit upon both sides
thereof. This is accomplished as follows:-N is a thumbscrew held in position by
a sleeve on the sliding plate E, and working into the fulcrum plate b₁ at t (see
Figures 2 and 3) above described. By turning this screw the fulcrum plate 6', into
which the screw a (as the fulcrum of the cam lever u) is secured, will be moved
nearer to or further away from the knee arm v, and it will change the fulcrum of
this cam lever, so that the change plate D, acted upon by the knee arm v, will be
thrown over a lesser or greater extent, as may be required to produce the stitches at
the same distance from the button hole slit on both sides thereof. P is the carrying
plate projecting through a slot in the upright end q of the bed plate, and connected
to the feed bar F, and at its outer end to the cloth plate T. The outer end of the
cloth plate projects over the plate of the sewing machine to the proper point, and
has a rectangular opening through it, so that the fabric containing the button hole
may rest upon the cloth plate of the sewing machine. The fabric is here held in position
by the clamp U secured to the outer end of the clamping lever Q, which lever is
forced down and held in position by the small cam lever S, which is attached to a
hub D having a shaft passing through the lever Q and secured to the carrying
plate P. The inner end of the clamp lever Q is attached to a steel spring, which is
secured to the carrying plate, so that the cloth clamp U will release the fabric when
the pressure of the cam lever S is removed and the lever Q assumes an elevated
position, as shown in Figure 6. This cloth clamp U is an equalising clamp, and has
teeth for holding the fabric in the ordinary form; but instead of being rigidly
attached to the lever Qit has a loose bearing thereon, so that it will move laterally
(see Figure 6), and thereby equalize the pressure upon all parts of the fabric beneath
it without regard to the unequal thickness of such fabric, The fabric about the
button hole is frequently of unequal thickness, and the rigid clamp in ordinary use
will not hold the fabric securely in proper position while the button hole is being
stitched. By the use of this equalising clamp this difficulty is entirely removed, as
the clamp will adjust itself to the equal or unequal thickness of the cloth at both
ends of the button hole.
The operation of the Invention is as follows:-The fabric in which the button
hole is to be stitched is secured on the cloth plate T, as described, with the slit of
the button hole in the centre of the rectangular opening in such plate. The sewing
machine being started, motion will be given to the switch cam placed upon the
driving shaft of the machine, and from this through the cam follower upon the
lever B a vibratory motion will be given to the levers B and C, and by them a
reciprocating motion given to the sliding plate E and the various parts connected
thereto, as described. This motion, transmitted to the cloth plate and clamping
device as described, carries the button hole back and forth under the needle (the
hub I having been first adjusted to correspond with the length of the button hole
to be stitched, as herein described) in such manner that the needle will pass first
through the slit of the button hole (see No. 1, Figure 8), and next pass through the
cloth at the edge of the slit (see No. 2, Figure 8), making one stitch of the button
hole, and so on alternately. Before the needle can descend the second time through
the slit the feed dogs J' and J", moved as herein-before described, and working into
the teeth on the circles A and B under the crank wheel H, give a rotary motion

page_text: to the crank wheel, and, through the pitman G and the feed bar F, move the cloth
plate just far enough (the distance to be moved for each stitch having been regulated
by the adjustment of the arm j by the screw M, as herein-before described) for the
succeeding stitch (No. 3, Figure 8). This motion continues until one side of the
button hole, as herein-before described, is stitched, when the cloth carrier and
attachments have arrived at the point where the pitman G is about to pass the
centre of the crank wheel and reverse the motion of the feed bar F. At this point
the cam u attached to the shaft of the crank wheel H will have reached one of
the projections 81 in the lever u. The cam u working against one of these
projections moves forward or backward the knee arm v attached to the opposite end
of this lever u, and by its attachment to the change plate, herein-before described,
will move such change plate, and thereby throw the cloth plate under the needle to
the unstitched side in a position for the button hole to be worked as before (the
fulcrum plate 6' having been properley adjusted, as herein-before described).
It will be observed that this change from side to side is so gradual that several
stitches are made in the ends of the button hole as the fabric is moved over, thereby
thoroughly working and strengthening the ends of the button hole.
The peculiar mechanism for and manner of working the ends of the button hole
have been fully described. By reference to Figure 8 the result thus accomplished is
clearly shown, the needle making the holes around the button hole in the order
they are numbered. As simply the needle holes are here shown it is obvious that
with the thread carried from each one of these holes to the next upon both the
under and upper sides of the fabric that a very strong and durable button hole is
made, and especially will the ends of the button hole be rendered very secure.
After the button hole has been passed entirely around under the needle the crank
wheel H has of course made one entire revolution, and leaving the button hole in
the position it was when the stitching upon it commenced, and the revolution of the
button hole under the needle will continue and the button hole be stitched around
as many times as desired or until the machine is stopped.
It will also be observed that if the button hole be placed in its proper position on
the cloth plate, as herein-before described, the position of the cloth plate will make
no difference with the stitching, as the button hole will be in proper position for
the needle and the stitching be as well commenced at one part of the button hole
as another.
It will also be observed that this device may be readily and simply adjusted to
work button holes of any reasonable size, and with such a stitch or degree of
fineness and such depth of stitch as may be desirable.
Also that after such adjustment the various parts of the device are automatic, and
it will perform its work by putting the machine in motion, as described.
Having thus fully described the Invention, and the manner of carrying the same
into effect, I declare that what I claim as new and desire to cover by Letters
Patent is,
First. The sliding plate E gibbed in ways on the bed plate of a button-hole
attachment, and working in a direct line for the purpose of vibrating the cloth
carrier and the button hole under the needle, in combination with a device for
transmitting from the sewing machine a longitudinal reciprocating motion to such
sliding plate, substantially as herein described.
Secondly. In a button-hole attachment a revolving crank wheel, through which a
lateral motion is transmitted to the feed bar, in combination with an adjustable
pitman, substantially as and for the purpose herein described.
Thirdly. The adjustable pitman G in combination with the crank wheel, in which
it is adjustable, and the feed bar, arranged and operated, substantially as herein
described, for the purpose of feeding the button hole entirely around under the
needle.
Fourthly. A crank wheel having feed teeth arranged thereon in circular form,
and one or more feed dogs working therein, and a feed lever with an adjustable arm
connecting such lever with the sliding plate E, by means of which a uniform rotary

page_text: motion is imparted to the crank wheel, substantially as and for the purpose herein
described.
Fifthly. In a button-hole attachment, feed teeth arranged upon arcs of circles
having different chords, such circles being formed upon or connected with the
revolving crank wheel, and the teeth being operated by feed dogs or other suitable
mechanism for the purpose of making the pitman give a uniform throw to the
feed bar.
Sixthly. The cam ull attached to the shaft of the crank wheel and working
against a lever connected with the change plate D by an arm, substantially as
herein described, for the purpose of moving the change plate D, so that the unstitched
side of the button hole will be carried under the needle at the proper time for the
purpose herein described.
Seventhly. The cam lever u having an adjustable fulcrum, by means of which
the throw of the change plate D may be regulated, substantially as and for the
purpose herein described.
Eighthly. The change plate D in combination with the lever u, cam ul, and knee
arm v, or other suitable mechanism by which the change plate, through the attached
cloth plate, will carry the unstitched side of the button hole under the needle.
Ninthly. The cam lever u in combination with cam u¹¹, crank wheel H, and knee
arm v, substantially as and for the purpose herein-before described.
Tenthly. The feed lever C", dogs J, J", and the teeth on crank wheel H, in
combination with the adjustable arm j, by which the fineness or closeness of stitch
is regulated, substantially as herein described.
Eleventhly. The equalising cloth clamp U secured by a loose bearing to its
projecting bar or lever Q for the purpose of making it adjustable to any inequalities
there may be in the fabric containing the button hole.
In witness whereof, I, the said William MoIntyre Cranston, have hereunto set
my hand and seal, this Twenty-eighth day of February, One thousand eight
hundred and seventy-eight.
WILLIAM MCINTYRE CRANSTON. (L.S.)