Improvements in Trimming Attachments for Machines for Sewing Looped Fabrics.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in Trimming Attachments for Machines for Sewing
Looped Fabrics.
I, ADELBERT LEE TRAVER of Philmont, Columbia County, State of New York,
United States of America, Manufacturer of machinery_for knit goods, do hereby
declare the nature of my invention for IMPROVEMENTS IN TRIMMING ATTACHMENTS FOR
MACHINES FOR SEWING LOOPED FABRICS, and in what manner the same may be
performed, to be particularly described and ascertained by the following statement :-
My invention is an attachment, applicable to machines for sewing looped fabrics,
of the class known as turning-off machines. This attachment embodying my invention;
derives its motion from the inain shaft of the sewing mechanism and by a process of
stitch breaking and ravelling, levels to a uniform height and prepares the edges of the
fabric after they are impaled upon the pin-plate and are being carried by it to the
sewing mechanism.
Referring to the drawings: Fig. 1 is a top view of my invention together with
a portion of the turning-off machine. Fig. 2 is a section through the line X X Fig. 1,
showing the means for removing the ravelled and separated portions of the fabric.
Fig. 3 is a section through the line YY Fig. 1, showing the stitch breaking and
ravelling mechanism. Fig. 4 is a section through the line ZZ, looking in the direction
of the arrow a. Fig. 5 shows in perspective view, the parts directly concerned in
stitch breaking and ravelling, and Fig. 6 shows in perspective view the parts directly
concerned in the removal of the ravelled and separated portions of the fabric.
A machine for sewing looped fabrics of the class of turning-off machines, to which
an attachment embodying my invention is applicable, consists of the following
elements: first, a pin-plate 1, Figs. 1 and 2, having on its periphery projecting
points on which the edges 2 and 3 of the fabric to be united are placed by the
operator, and second, a sewing machine 4, of which is its main shaft and 6 is its
sewing needle. The pin-plate is made in the form of a ring, of which a portion is
shown in the drawing. It is given a motion in the direction of the arrow b and
serves to carry the fabric impaled on its points and feed it to the sewing-mechanism.
On account of the ring form of the pin-plate, the portion of the machine within it
becomes a part of the framework convenient for the support of my attachment. The
main frame 7, of my attachment is secured to the frame of the turning-off machine
so as to bring the operative parts of it in the proper position to act on the fabric
carried by the pin-plate. In Figs. 1 and 2 the main frame of my attachment is
shown connected to the turning-off machine through the sliding joint 8 and the angle
piece 9. To effect the adjustment on this joint, a stud rigid to the frame passes
through a slot in this angle piece and is threaded for a clamping nut. A thumb
screw 10 passes through the angle piece and taps into the stud, whereby the frame
may be drawn upwards and its height above the pin-plate thereby accurately adjusted.
The preparation of the edges of the fabric for sewing together involves two distinct
operations. The first is illustrated in Figs. 3 and 5. The fabric impaled on the pin-
plate with its edges projecting more or less above the points is to be trimmed to a
uniform height. For this purpose it passes between a wedge shaped piece 13 and a
guide 14. The wedge has two vertical and parallel sides, a horizontal lower and an
inclined upper edge. These edges are blunt or rounded so as not to cut the fabric
immediately on coming in contact with it, and it is intended that they shall not be
of a shape that will co-operate in the manner of a shear with the edges of the opening
In the guide on the opposite side of the fabric. The lower edge of this wedge shaped
piece is horizontal, as is also the direction of motion with which the wedge is pushed
Into the fabric, so that this edge will lie close to and parallel with the points on the
pin-plate and serve to hold the fabric down on the points against the upward straining
action of the inclined upper edge. The function of the guide-plate 14 with its slot
Pd

page_text: is to support the fabric while it is being entered by the wedge. The action of the
wedge on entering a loop of the fabric is to enlarge it, until it breaks if both ends
forming the loop are fast in the fabric, and to ravel it if either end has been freed
by the breaking of an adjoining loop. By thus avoiding a shearing or cutting action
the fabric is ravelled apart wherever possible and no short pieces of thread are produced
that will clog the machine. The second operation performed by my attachment is
for the removal of the ravelled and loosened portions of the fabric. After the first
operation of breaking and ravelling has been performed by the wedge, the fabric is
carried by the pin-plate in front of the jaw 16. Mechanism operating this jaw,
carries it forward till it grips the loosened edges of the fabric against the smooth
surface of the guide plate 14 as shown in Figs. 2 and 6, then it rises carrying the
fabric with it, then draws away from the plate and returns to its first position. For
the purpose of conveying motion from the sewing-mechanism to the above elements,
universal joints and connections 17, 18 and 19, communicate motion from the sewing-
machine shaft to the cams 20 and 21. These are four-inotion-cams identical in form,
so that one may be considered as a continuation of the cam surface of the other.
They operate on a bar 23 and a lever 22 mounted so as to slide and rock on the
stud 24. The cam surfaces on the lever 22 form a square. The cam in its revolution
presses successively against these surfaces so as to impart to the lever a motion, first,
towards the fabric to the position shown in Fig. 2, next, upward, then backward and
downward to the point of starting. Two of the cam surfaces on the bar 23 correspond
with those on the lever 22, but on account of the yoke for the cam being elongated,
this bar 23 receives no oscillating motion upward and downward but only a recipro-
cating one backward and forward from the cam. A stud 25 fast in the lever 22 plays
in a slot 26 in the bar 23 with the upward and downward movement of the former
lever. This stud may be clamped rigidly in the slot and the bar thus made fast to
the lever so that the two become as one lever operated upon by one four-motion cam.
In practice I construct my attachment on this latter plan, with a single lever and cam,
as there are then fewer parts and the vertical movement imparted to the wedge
though not essential is not objectionable. For the purpose of broadening my patent
I have however shown and described the wedge 18 as separately mounted with the
bar 23 from the jaw 16 and shown that a simple reciprocating motion is sufficient to
enable it to perform its function. The wedge 13 is detachable from the bar 23 for
the convenience of renewal. The jaw 16, however, is not rigid with the lever 23
but is supported so that it can yield against the spring 27 according to the thickness
of the fabric that may lie between this jaw and the guide-plate 14. I find that a
second guide 29 on the same side of the fabric as the wedge 13 and jaw 16 contributes
to the successful operation of the machine by guiding the fabric and preventing the
accumulation of loose threads on the operating parts.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A fabric trimming attachment combined with the pin-plate of a turning-off
machine, a bar having a wedge shaped end consisting of two parallel sides,.a lower
edge lying close to and parallel with the points on said pin-plate, and an inclined
upper edge of sufficient length and inclination to give to the wedge shaped part near
the rear end sufficient dimension to draw out or break the loops of the fabric, a guide
plate lying against and supporting the opposite side of the fabric from said bar and
wed dge and having a slot opposite said wedge, mechanism whereby said bar may be
reciprocated in the direction of the lower edge of its wedge shaped end through said
slot in said guide-plate, and a frame for supporting and guiding said bar for support-
ing said guide-plate and carrying said mechanism, substantially as and for the purpose.
set forth.
2. A fabric trimming attachment combining with the pin-plate of a turning-off
machine, a bar having a wedge shaped ond consisting of two parallel sides, a lower
edge lying close to and parallel with the points on said pin-plate and an inclined

page_text: upper edge, a guide-plate having a slot of such width as to just admit said wedge
shaped end, and lying against and supporting the opposite side of the fabric carried
by said pin-plate from said wedge shaped end, and with its slot opposite thereto, a
four-motion-cam, for imparting motion to said bar by acting upon the surfaces
thereof the said cam and bar working at right angles to each other, mechanism for
revolving said cam and a frame for supporting and guiding said bar, for supporting
said guide-plate and carrying said mechanism, substantially as and for the purpose
set forth.
3. A frabric trimming attachment combining with the pin-plate of a turning-off
machine, a lever bearing on its end a jaw opposite the edge of the fabric impaled on
said pin-plate, a spring between the lever and the jaw, a guide-plate lying against and
supporting the opposite side of the fabric from said jaw, a four-motion-cam, mechanism
for revolving said cam and a frame for supporting and guiding said lever, for
supporting said guide-plate and carrying said mechanism, substantially as and for the
purpose set forth.
4. A fabric trimming attachment combining with the pin-plate of a turning-off
machine, a lever bearing a wedge shaped end for severing the fabric and a jaw where
it can operate on the fabric between said wedge and the sewing-mechanism, a guide-
plate lying against and supporting the opposite side of the fabric from said wedge
and jaw, a slot in said guide-plate opposite said wedge, a cam acting on this lever to
slide it toward the fabric and then rock the end bearing the wedge and jaw upward
from the pin-plate, mechanism for revolving said cam and a frame for supporting
and guiding said lever, for supporting said guide-plate and carrying said mechanism,
substantially as and for the purpose set forth.
1
1
2000
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent.
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent.