Improved Attachment for Sewing Machines for Making Blind Stitching and Overseaming.
Year: 1898

page_text: Date of Application, 28th Mar., 1898-Accepted, 7th Jan., 1899
COMPLETE SPECIFICATION.
Improved Attachment for Sewing Machines for Making Blind
Stitching and Overseaming.
I, HENRY BIRKBECK, of the Firm of Tongue and Birkbeck, 31, Southampton
Buildings, Chancery Lane, London, Fellow of the Chartered Institute of Patent
Agents, do hereby declare the nature of this invention (communication to me
from abroad by William Daniel Elger, of No. 18, Broadway, Borough of
Manhattan, in the City of New York, in the County of New York, in the State
of New York, in the United States of America, Merchant) and in what manner
the same is to be performed, to be particularly described and ascertained by the
following statement: --
The object of this invention is to provide a new and improved attachment for
sewing machines for making blind stitching and overseaming, for exampla,
such as is used for holding down and finishing the raw edge of a piece of fabric
that has been folded over or for uniting two edges or two layers of fabric in
such a manner as to be highly ornamental and at the same time, so as not to
show on the exposed or outer face of the material, and which attachment is
simple in construction, strong and durable, can be used with any sewing machine
and can be adjusted very easily for various kinds of stitches.
The invention consists in the combination with a base plate which is suitably
held on the sewing plate of the sewing machine and carries a movable member
which moves the fabric away from the path of the needle, at each alternate stitch,
the fabric being drawn back by the tension of the thread, and suitable mechan-
ism being provided for operating this movable member from the needle bar
of the machine.
The invention also consists in certain new and original stitches which can be
made by means of this attachment.
The invention also consists in the novel construction and combinations of parts
as will be fully set forth hereinafter and finally pointed out in the claims."
In the accompanying drawings forming a part of this specification and in
which like letters of reference indicate like parts in all the figures:
Figure 1 is a plan view of my improved attachment showing one construction
of the same.
Figure 2 is a side view of the construction shown in Figure 1.
Figure 3 is a detail plan view of the underside of the spring pawl lever shown
in Figures 1 and 2.
Figure 4 is a vertical sectional view on the line 4, 4, of Figure 1.
Figures 5 and 6 are detail plan views of part of the construction shown in
Figures 1 and 2, showing the parts in different positions.
.
Figures 7 and 8 are vertical sectional views on the lines 7-7 of Figure 5
and 8-8 of Figure 6, respectively.
Figure 9 is a plan view similar to Figures 5 and 6, showing a slightly modified
construction.

page_text: Figures 10 and 11 are vertical sectional views on the lines 11-11 of Figure 9,
showing the parts in different positions.
Figure 12 is a plan view of another construction of my attachment.
Figure 13 is a side view of the same.
Figure 14 is a plan view of part of this construction showing the parts in
positions other than those shown in Figure 12.
Figure 15 is a similar plan view showing a slight modification.
Figure 16 is a plan view of another construction of my improved attach-
ment.
Figure 17 is a side view of the same.
Figure 18 is a plan view of the same construction showing the parts in
positions other than those shown in Figure 16.
Figure 19 is a plan view of another construction of my attachment, parts being
omitted.
Figure 20 is a side view of the same.
Figures 21 and 22 are vertical sectional views showing a slight modification
of the fabric pushing device for making the stitch shown in Figures 27 and 28.
Figure 23 is a face view of one form of the stitching produced by means of
my attachment.
Figure 24 is a vertical transverse sectional view of the same on the line 24—24.
of Figure 23.
Figure 25 is a view similar to Figure 23 and showing a slight modification of
the stitch.
Figure 26 is a vertical transverse sectional view on the line 26-26 of
Figure 25.
Figure 27 is a face view similar to Figure 23 showing another modification
of the stitch.
Figure 28 is a vertical transverse sectional view on the line 28-28 of
Figure 27.
Figure 29 is a face view similar to Figure 23 but not having an exposed
edge of the fabric.
Figure 30 is a vertical transverse sectional view on the line 30-30 of
Figure 29.
A number of different constructions of the improved attachment have been
shown, which only differ from each other in details, the general principle being
substantially the same in all.
In all the figures A, represents the presser bar of the sewing machine, B, the
needle bar, and C a base plate which rests upon the sewing plate of the machine
and can be secured to the same if desired, after it has been adjusted.
A block or piece E, is provided with a socket for receiving the lower end of
the presser bar A, which is secured in said socket and on said block a presser
foot F is mounted to slide, which presser foot can be adjusted by means of a
screw F¹, and to said presser foot the plate C is attached preferably by means
of two pins which project upward from the plate C into eyes F in the presser
foot.
A standard G projects upward from the plate C and to the same an angle
lever His pivoted and is provided on its upper end with a lateral extension H¹
upon which the lateral projection B on the needle bar B can act when said
needle bar rises so as to swing said lever upward, the said lever being swung
down during the downstroke of the needle bar by a suitable spring B attached
to the standard G and resting against the upright shank of the said lever H.
The presser foot F is provided in the edge facing the plate C with a recess J
through which the needle passes and into which part of the edge of the fabric b
or fabrics is moved when the needle is not to pass through the fabric.
The above described parts are substantially the same in the various constructions.
In Figures 1 to 11 the plate C is provided with a recess K open toward the
presser foot F and in said recess a triangular cam piece L is pivoted centrally

page_text: nd vertically in the plate C so as to turn on its vertical axis, and above the
late Ca toothed wheel M having 6 teeth is attached to the top of said cam L,
he toothed or ratchet wheel M being engaged by a spring pawl M¹ pivoted on
lever N mounted to rock on the neck L of the triangular cam so that for each
troke of the lever N the ratchet wheel M is rotated the distance of one tooth.
By means of a link O the swinging end of the lever N is connected with
he lower end of the angle lever E so that for each up stroke of the needle bar
he wheel M is turned one sixth of its circumference and the cam L rotated on
ts axis correspondingly.
As the cam has three sides and the ratchet wheel six teeth it follows that for
one up stroke of the needle bar the cam will have one side parallel with the edge
of the plate C and at the next up stroke of the needle bar the cam will be turned
to such an extent that one of its angles projects beyond the edge of the plate C
into the recess J of the presser foot, and at the next upstroke of the needle bar
the cam will again be turned to such an extent that one side will be parallel with
the edge of the plate C and so on.
Thus for each alternate stroke of the needle bar an angle of the cam L will
thus be projected into the recess J of the presser foot.
The cam is provided in each angle with a vertical slot P extending toward
the centre of the cam and when an angle of the cam extends into the recess J
of the presser foot the needle a in its descent during which descent the cam L
remains stationary, passes through said slot P but cannot pass through the
fabric as the angle of the cam has pressed part of the edge of the fabric into
the recess J in the presser foot, as shown in Figures 6 and 8.
At the next descent of the needle the one side of the cam L is parallel with
the edge of the plate Cand no part of the cam extends beyond said edge of the
plate, against which the edge of the fabric b now rests snugly, as shown in
Figures 5 and 7 and thus the needle passes through the fabric and so on.
SO
To make a blind stitch the fabric is folded as shown in Figures 6 and
that the needle at the down stroke passes through the bottom layer and through
the fold, but not through the thickness of the fabric at the fold, that it does not
pass through the fabric at the fold from the inner to the outer surface but passes
through the fabric between the inner and outer faces, as in Figure 6 and at the
next down stroke the fabric is pushed out of the way by one corner of the cam L
so that the needle does not pass through any of the fabric as shown in Figure 8.
In certain cases it is desirable to have the needle pass through the bottom
layer at each stroke of the needle and only miss the blind stitch part at each
alternate stroke as this forms a blind and over seam stitch of another appearance.
For this purpose the cam L is shaped so that only the bottom parts L² of the
angle project beyond the edge of the plate C and this is accomplished by reducing
the dimensions of the cam in such a manner that only the bottom parts L³ have
the original dimensions and the upper part is reduced as shown.
As shown in Figures 10, and 11, the fold of the fabric is not pushed back
at all by the cam and the bottom layer only is pushed out of the path of the
5 needle a.
Figures 12 to 15 show a modification of the device in which the triangular
cam for pushing the fabric b out of the path of the needle for each alternate
down stroke is replaced by two swinging fingers Q which are pivoted in the
recess K of the plate C on a pin Q1 in such a manner that when swung together
0 their ends project beyond the edge of the plate C leaving space between them
for the needle a to pass as shown in Figure 12 and when swung apart are
entirely within the recess K as shown in Figure 14.
When the fingers Q are swung out they push back the edge of the fabric b
so that the needle can not pass through the fabric and when they are swung
55 back into the recess the tension in the thread draws the edge of the fabric up
against the edge of the plate C and so on alternately, so that for each alternate

page_text: down stroke of the needle the same passes through the layers in substantially
the same manner as herein before described.
Each finger Q has an arm Q2 which arms are connected by pivoted links Q³
with one end of a rocking lever R pivoted on the base plate C and pressed in
the direction from the edge of the same by a spring R¹.
A triangular cam R² rests on the edge of said lever R¹ and is connected with
a six tooth ratchet wheel R³ on which a spring pawl Si can act which is pivoted
on a reciprocating slide S on the base plate C and is pivotally connected with
the lower end of the angle lever H.
With this arrangement the lever R is swung toward the edge of the plate C
for one down stroke of the needle bar and at the next down stroke of the needle
bar the cam R2 is turned so that one of its sides is parallel with the inner edge
of the lever R and the lever is pressed back by the spring S2 and thereby the
links are drawn back and the fingers Q swung into the recess K whereas at
the next down stroke of the needle bar the cam R2 is turned so that one of its
angles presses the lever R toward the edge of the plate C whereby the fingers Q
are swung toward each other and out of the recess D and so on.
As shown in Figure 15 one finger Q may be used instead of two but I prefer
to use two.
Analogous to the construction shown in Figures 9 to 11 the lower parts of
the fingers only can be of sufficient length to project beyond the edge of the
plate C so that the upper layers will not be pushed back but only the bottom
layer as is shown in Figures 9 to 11.
In Figures 16 to 18 I have shown a further modification of the device in
which I also provide the two swinging fingers Q in the recess K which fingers
in this case have their swinging ends pivotally connected with two levers T
pivoted on the top of the plate Cand between the inner bent ends T of which
a triangular cam T2 is located which alternately presses the levers from each other
and permits them to be brought together by the spring T3 acting on said
levers.
As shown in Figure 18 the triangular cam T2 has pressed the levers T from
each other and thereby swung the fingers Q together and in Figure 16 the cam
has such a position as to permit the spring 13 to swing the levers toward each
other whereby the fingers Q are swung apart and entirely within the recess K.
The cam T2 is turned step by step from the angle lever H by means of a ratchet
and spring pawl lever such as is shown in Figure 3.
In the construction shown in Figures 19 and 20 the fabric b is not pushed
away from the edge of the plate Cas in the other constructions shown, but is
gripped positively and pulled away for each alternate down stroke of the needle
bar.
The two shaped levers W are pivoted to each other at W to swing toward
and from each other vertically and also to swing together in the horizontal
plane, a spring V pressing them into contact with a triangular cam V₁ which
is operated from the needle bar in the manner previously described.
The levers are provided at their outer ends with serrations & and at the
opposite ends are pressed from each other by a spring 9, whereby the serrated
ends are pressed toward each other or against the fabric b between such ends
of the levers.
A wedge shaped cam piece h is held horizontally on the plate C in such a
manner that it extends in between the levers W. By the action of the cam Vi
and spring on the levers W they are oscillated horizontally and their serrated
ends d are swung toward and from the edge of the plate C.
When the serrated ends swing from the edge of the plate C they also move
toward the thinner end of the cam piece h permitting the spring g to press the
serrated ends upon the fabric 6 which is thus positively moved from the edge of
the plate C and is thus missed by the needle in its down stroke.
When the serrated ends swing toward the plate C under the action of the

page_text: cam the levers slide up the wedge cam h and are separated and thus do not
grip the fabric while moving toward the plate C and the fabric can be fed
forward and under the action of the tension of its thread is drawn against the
edge of the plate C and so on.
To form the stitch shown in Figures 27 and 28 the pusher U, that is the edge
of the part that pushes the fabric away must be recessed at the bottom as shown
at U in Figures 21 and 22 so that when the fabric is pushed away by the
pusher the upper part of the folded fabric only is pushed away and the bottom
part remains in place as shown in Figures 21 and 22.
The needle thus makes a blind stitch at every alternate down stroke in the
upper fold of the fabric, that is the blind stitches E in Figures 27 and 28 and
at each down stroke makes a blind stitch in the lower fold of the fabric, that
is the blind stitches G4 in Figures 27 and 28.
In Figures 23 to 30 some of the stitches that can be made by means of the
attachment are illustrated.
The stitches are all formed of two threads a and b which are interlocked
with each other and drawn through the fabric in such a manner as to form a
zig zag stitch line and to unite the two layers of fabric.
The two layers of fabric A and B may consist of two independent layers as
shown in Figures 29 and 30 or the upper layer may be formed by doubling
over the lower layer B4 as shown in Figures 23 to 28.
As shown in Figures 23, 25, 27 and 29 the thread a forms a zig zag line on
the face of the upper fabric layer A and on said upper face of the layer A4
the thread 64 is interlooped with the thread a' at every alternate angle of the
zig zag line formed by the thread a that is at the points C.
When the upper layer has an edge, said points C, may be a greater or less
distance from the edge of the upper layer, and thus more or less of the thread 64
will show on the upper surface of the upper layer A*, as for example in Figures 23
and 24, but in all cases the thread 6 is interlooped with the thread at at the
alternate angles, that is, at the points C4, and the loops thus formed are upon
the upper surface of the upper layer.
The thread a is drawn through the thickness of the layer A' at the points or
angles D of the said zig zag line formed by the thread a and is interlooped
below the layer A4 with the thread 64, which from the points C+, passes over
the edge of the upper layer A* and passes through the lower layer B between
the upper and lower faces of the same, a greater or less distance, as a blind
stitch E, beginning at et and ending at the looping with the thread a below the
layer A4, and thus not showing in any manner on the under or outer side of
the lower layer B*.
That part of the thread 6 passing over the edge of the upper layer A is
designated by e³.
In the stitch shown in Figures 25 and 26 the upper thread a is also drawn
through part of the upper layer A as a blind stitch G4 but in all other respects
the stitch is formed in the manner previously described and shown.
In the stitch shown in Figures 29 and 30 the upper layer has no edge adjacent
to the line of stitches but in all other respects the stitch is the same as those
described.
If the upper layer A were cut, in Figures 29 and 30, along the line e e es
the result would be the same as that shown in Figures 23 and 24 with the only
0 difference that the blind stitch E would begin directly below the edge, thus
formed by cutting the upper layer, and not a short distance inward from said,
edge as shown in Figures 23 and 24.
In all the stitches shown and described the thread a' forms zig zag lines on
the face of the layer and is interlooped with the thread 6 at alternate angles and
5 alternately on the upper and lower surface of the upper layer.
I am aware that a zig zag or serging stitch has been produced by means of
two threads, and a serging machine, on the edge of a fabric, but such stitch is

page_text: not like the one that I have shown and described and I also am aware that a
single thread looping stitch has been made on the edges of fabric for the purpose
of securing and finishing such edge, but this stitch, better known as the glove
sewing or overseaming stitch is not like the one I have shown and described.
These stitches all show on both faces of the fabric whereas my improved stitch-
ing shows on the inner face of the fabric only as part of the stitch is a blind
stitch and only passes partly through the fabric and thus can not appear on
the outer face thereof.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. The combination of a plate adapted to be attached to the presser foot, of
a sewing machine and having a recess opening toward the presser foot with a
fabric shifting member mounted within said recess to have a movement on a
circular or curved line within said recess and means for operating said mem-
ber from the needle bar whereby the said member is projected beyond the edge
of the said plate for each alternate down stroke of the needle bar, substantially
as herein shown and described.
2. The combination with a plate adapted to be attached to the presser foot of
a sewing machine and having a recess opening toward the presser foot, with a
fabric pushing member mounted within said recess on a pivot to have a motion
on a circular line, part of the free end of said member being recessed in its vertical
edge and means for operating said member from the needle bar, whereby said
member is projected beyond the edge of the said plate for each alternate down stroke
of the needle bar and thus for each alternate down stroke of the needle bar
pushes part of the fabric out of the path of the descending needle, substantially
as herein shown and described.
3. The combination with a plate adapted to be attached to the presser foot,
of a sewing machine with a movable member for positively gripping a fabric
and having a movement toward and from the edge of the said plate and means
for operating said positive fabric gripping member from the needle bar, sub-
stantially as herein shown and described.
4. The combination of a plate adapted to be attached to the presser foot of a
sewing machine, with a fabric gripper composed of two members, one below
and the other above the fabric to be sewed, which grippers are mounted to move
toward and from the edge of said plate, and to move toward each other, to posi-
tively grip the fabric while moving from the edge of the plate and to separate
while moving toward the edge of the plate and means for operating said jaws
from the needle bar, whereby the edge part of the fabric is moved out of the
path of the needle at each alternate down stroke of the same, substantially as
herein shown and described.
5. The combination with two layers of material, of the two threads a and b
uniting them, the thread a forming a zig zag line on the face of the upper layer
and the thread 6 being passed as a blind stitch through the lower layer and
being interlooped with the thread a alternately on the upper surface of the
upper layer and below said upper layer, substantially as herein shown and
described.
6. The combination with two layers of material of the two threads a and b
uniting them, the thread at forming a zig zag line on the upper face of the upper
layer and the thread 64 being passed through the lower layer as a blind stitch
and interlooped with the thread at at the inner end of the said blind stitch and
below the upper layer and said thread 6 being also interlooped with the thread at
on the surface of the upper layer and alternately with the interlooping of the said
threads below said upper layer, substantially as herein shown and described.
7. The combination with two layers of material of two threads at and 64
uniting the two layers, the thread a forming a zig zag line on the upper surface

page_text: of the upper layer and the thread 64 being passed through the lower layer as
a blind stitch and being interlooped with the thread a alternately above and
below the upper layer and the thread a being passed, as a blind stitch, through
the upper layer, substantially as herein shown and described.
1 1000
TONGUE & BIRKBECK,
Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.