IMPROVEMENTS IN SEWING PROVISIONAL SPECIFICATION
Year: 1880

page_text: LETTERS PATENT to Henry Greenwood, of Albion Works, Leeds, in the
County of York, Machinist, for an Invention of "IMPROVEMENTS IN SEWING
PROVISIONAL SPECIFICATION left by the said Henry Greenwood at the
Office of the Commissioners of Patents on the 19th August 1880.
HENRY GREENWOOD, of Albion Works, Leeds, in the County of York, Machinist.
"IMPROVEMENTS IN SEWING MACHINES."
This Invention relates to an improved under feed for sewing machines which
have the shuttle for carrying the locking thread situate above the work, the
object being to provide against the formation of a burr on either side of the leather
where the stitch holes occur.
In carrying out this object it is necessary also to provide a special arrangement
of looper for laying the sewing thread in the hook of the vertical needle.
The Invention it may be remarked applies to sewing machines using both waxed
and dry thread, and in which any form of shuttle situate above the work is
employed.
The feed of the work is effected by means of a point somewhat larger in
diameter than the needle, which point serves also to pierce the work preparatory to
the descent of the needle.
This piercing point is carried by a vertical lever, which is so actuated that the
point is enabled to retire to such a position (irrespective of the length of the stitch
required), as to be out of the way of the "looper" when throwing in the thread.
The improved looper is so actuated by canis that its eyelet through which the
thread passes will describe any required path, either around the hook or across its
path, and then remain stationary in a direct line with the centre of the hook during
the time occupied by the thread in passing up and down through the material
under operation, thereby reducing the friction on the thread to a minimum.
The piercing and feeding point is carried at the top of a vertical lever, which is
slotted longitudinally to receive a fixed fulcrum pin, and terminates at bottom in
a ball which rests in a cup at the forward end of a rocking frame.
This frame is so mounted as to be capable not only of rocking vertically, but of
swivelling on a fixed centre, and it is provided at its rear end with bowls which

page_text: "
bear upon a compound rotating cam, so formed as to impart the requisite compound
motion to the frame. Thus the piercing point is caused to strike upwards into the
work, and then to move the work forward until the pierced hole is brought
immediately below the hooked needle. The point then retires from the work, and
its rock lever falls back to afford space for the advance of the looper.
The lateral or swivel motion of the rocking frame, which gives to the feed its
backward and forward movements is regulated by an adjustable stop on the
framing of the machine.
The forward extremity of this rock lever is fitted laterally with an inclined
projection, which is caused by a tension spring to bear against the adjustable stop,
and by this means the length of the stitch is regulated, and the back motion of the
feed is effected.
The eyelet of the looper (through which the thread passes) is fitted to the upper
end of a vertical .lever mounted on a swivelling pivot as its fulcrum. The lower
end of this lever terminates in a ball which is enclosed in a cup formed on one end
of a horizontal sliding piece. The opposite end of this sliding piece carries two
bowles or runners, one on its upper and one on its under side. These runners are
kept in contact by means of spiral springs with two cams keyed on the main shaft
of the machine. The sliding piece is mounted in a carriage, which swivels freely
on a vertical pivot carried by the framing. These cams are so formed as to make
the eyelet of the looper first pass around the hook to throw in the thread, and then
after the hook has ascended to take up a central position immediately under the
hook centre, and to remain stationary until the thread has passed up and down
through the material, after which the eyelet retires to make room for the feed point
which now comes into operation.
The mechanism as above described is arranged for use in what is known as the
"post machine;" but when adapting the Invention to table or horizontal arm
machines, the feeding point and the looper eye will be carried by horizontal in
place of vertical levers; in other respects the mechanism will be substantially the
same as that above described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Greenwood in the Great Seal Patent Office on the 19th
February 1881.
HENRY GREENWOOD, of Albion Works, Leeds, in the County of York, Machinist.
"IMPROVEMENTS IN SEWING MACHINES."
This Invention relates to the adaptation of a pricker feed to that class of
sewing machines which has the shuttle for carrying the locking thread situate
above the work, and is chiefly used in the sewing of leather, the advantage of
such feed being that it provides against the formation of a burr on the underside
of the leather where the stitch holes occur.
When using a pricker feed, it is necessary to provide a special arrangement of
looper for laying the sewing thread in the hook of the vertical needle.
The Invention it may be remarked applies to sewing machines using both
waxed and dry thread, and may be used irrespective of the form of shuttle
employed.
In Sheet I. of the accompanying Drawings Fig. 1 is a vertical side section of
so much of a post sewing machine (which has the shuttle above the work), as will
serve to illustrate my Invention, and Fig. 2, Sheet II., is a vertical section of the
post with its fittings taken at right angles to Fig. 1.
A is the hollow post closed with a cap on which the work to be sewn is placed,
and through this cap plays the hooked needle a; b is the pricker feed, and c, the
looper. The pricker 6 for feeding the work is somewhat larger in diameter than
the needle a, and it serves also to pierce the work preparatory to the descent of the
needle.
This pricker or piercing point b is carried by a vertical lever B, which is so
actuated that the point is enabled to retire to such a position (irrespective of the
length of the stitch required) as to be out of the way of the "looper
throwing in the thread.
"
c when
The improved " looper" is so actuated by cams that its eyelet through which
the thread passes will describe any required path, either around the hook or across
its path, and then remain stationary in a direct line with the centre of the hook
during the time occupied by the thread in passing up (and down, when a special
stitch tightener is used) through the material under operation, thereby reducing
the friction on the threads to a minimum.
The vertical lever B which carries the piercing and feeding point is slotted
longitudinally to receive a fixed fulcrum pin b', and terminates at bottom in a
ball, which rests in a cup at the forward end of a rocking frame B¹. This frame
is so mounted as to be capable of rocking vertically on a horizontal pin 62, and
horizontally on a fixed centre 63, and it is provided at its rear end with bowles b*
and 66, which bear upon a compound rotating cam B2 on the cam shaft of the
machine. This cam is so formed as to impart the requisite compound motion
to the frame B¹. Thus the piercing point is caused to strike upwards into the
work, and then to move the work forward until the pierced hole is brought
immediately below the hooked needle. The point b then retires from the work,
and its rock lever falls back to afford space for the advance of the "looper."
The lateral or swivel motion of the locking frame, which gives to the feeding
point or pricker its backward and forward movements is regulated by an
adjustable stop B³ on the framing of the machine, such stop having an inclined
face.
The forward extremity of this rock frame is fitted laterally with an inclined
projection 68 (see the detached view of the frame Fig. 1a), which inclined projection
is caused by a tension spring to bear against the adjustable stop B³. By adjusting

page_text: the position of the stop B³ the length of the stitch is regulated, and the required
back motion of the feed is ensured.
The eyelet of the looper c (through which the thread passes) is fitted to the
upper end of a vertical lever C mounted on a swivelling pivot c' as its fulcrum.
The lower end of this lever terminates in a ball, which is enclosed in a cup formed
on one end of a horizontal sliding rock lever C¹ mounted in a pivotted slide C*.
The opposite end of this sliding rock lever C¹ (see the detached view Fig. 2º),
carries two bowles c², c³, one on its upper and one on its underside.
These bowles are kept in contact by means of spiral springs with two cams C2, C3,
keyed on the cam shaft of the machine. These cams are so formed as to make the
eyelet of the looper first pass around the hook to throw in the thread, and then
after the hook has ascended to take up a central position immediately under the
centre of the book, and to remain stationary until the thread has passed up (and
down, when a special stitch tightener is used) through the material, after which the
looper retires to make room for the feed point which now comes into operation.
When adapting the Invention to table or horizontal arm machines, the feeding
point and the looper eye will be carried by horizontal in place of vertical levers; in
other respects the mechanism will be substantially the same as that above
described.
This arrangement is illustrated in Sheets III. and IV., where Fig. 3 represents in
side elevation so much of a sewing machine with the improvements applied thereto,
as will serve to explain the modifications required to adapt the Invention to a table
machine, and Fig. 4 is a plan view in partial section of the same parts. In this
arrangement the vertical levers B and C are dispensed with, the pricker or feeding
point b being mounted on the rocking frame B¹, and the looper c upon the rocking
sliding bar C. In other respects the arrangement differs little from that just
described, and the action of the parts is precisely the same; Fig. 4a shews the
adjustable stop B³ detached. In Fig. 4 it is shewn as attached by bolts to the
main-framing.
Having now set forth the nature of my Invention of "Improvements in Sewing
Machines," and explained the manner of carrying the same into effect, I wish it to
be understood that under the above in part recited Letters Patent, I claim,-
First. The adaptation to sewing machines constructed with a hooked needle and
shuttle above the work of a pricker feed, arranged and operating in the manner
and for the purpose above set forth.
Secondly. In combination with the pricker feed operating below the work, a
traversing looper which lays the thread within the hook of the needle, and then
brings its eyelet into a position immediately below the ascending needle, in the
manner and for the purpose above set forth.
In witness whereof, I, the said Henry Greenwood, have hereunto set my hand
and seal, the Sixteenth day of February, in the year of our Lord One
thousand eight hundred and eighty one.
HENRY GREENWOOD. (L.S.)