AN IMPROVED CONSTRUCTION OF HOOK FOR SEWING MACHINES
Year: 1875

page_text: LETTERS PATENT to John Keats, of Newcastle-under-Lyme, in the
County of Stafford, Boot Manufacturer, and Arthur Greenwood, of
Leeds, in the County of York, Engineer, for the Invention of “AN
Sealed the 2nd November 1875, and dated the 7th May 1875.
PROVISIONAL SPECIFICATION left by the said John Keats and
Arthur Greenwood at the Office of the Commissioners of Patents,
with their Petition, on the 7th May 1875.
We, JOHN KEATS, of Newcastle-under-Lyme, in the County of Stafford,
Boot Manufacturer, and ARTHUR GREENWOOD, of Leeds, in the County
York, Engineer, do hereby declare the nature of the said Invention
for "AN IMPROVED CONSTRUCTION OF HOOK FOR SEWING MACHINES," to be as
follows:-
In sewing strong or thick leather by the sewing machine great
difficulties have hitherto been experienced in producing fine stitching

page_text: similar to that of the best hand work, it being essential not only to use a
strong waxed thread, but also a strong hook for piercing the work and
fetching up the thread of the looper.
The most approved form of hook is made from a cylindrical rod of
steel, and it terminates in a conical point which serves to pierce the
leather. The tongue of the hook is central or nearly so, and it is made
by recessing the cylindrical rod at the back of the tongue.
This recess,
termed the throat, extends on either side of the bridge in the form of
hollow chamfers which die off near the point of the hook. These hollow
chamfers form recesses for the reception of the looper thread which is
doubled over the bridge, but which when drawn through the leather is
nevertheless subjected to great friction. To reduce this friction on the
thread an increased diameter has been given to the stem of the hook so
as temporarily to increase the opening for the passage of the thread. The
shape of this hook necessitates the making of oval holes in the leather,
the axis of which holes approach more or less near to the line of feed;
unless therefore a long feed is given the action of the hook will be
in piercing the leather to destroy its structural strength.
Now the objects of the present Invention are to reduce materially the
length of the stitches without impairing the structural strength of the
leather, and also to reduce the amount of friction put upon the looper
thread. In order to attain these objects we change the construction of
the hook, converting the piercing point into a cutting edge which
approaches more or less to the form of a chisel edge with rounded
extremities. This cutting edge will pierce the leather transversely of
the line of feed (say at about 80 degrees thereto), and the tongue of the
hook instead of taking a central position as in the ordinary hook will be
inclined to one side, thereby destroying the symmetry of the hook and
incidentally giving a broader bridge for the thread to be drawn over.
As the increasing perimeter of the hook passes into the leather an oval
hole will be formed transversely of the line of feed, and on the piercing
of the next succeeding hole, supposing no thread to be taken up by the
hook, this hole would be converted from an oval to a bean shape. As the
thread is drawn up by the hook in the longest axis of the hole a.
minimum amount of friction will be put upon it, and from the disposition
of the holes transversely to the line of feed, it will be understood that
sewing like the finest quality of hand sewing may be produced. By this

page_text: construction of hook we provide that when the looper thread in passing
through the leather is least protected by the hook the hook shall present
its full breadth to the leather, but a greatly diminished thickness, thus
allowing the leather to yield in the direction of the drag of the
thread.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Keats and Arthur Greenwood in the Great
Seal Patent Office on the 6th November 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
KEATS, of Newcastle-under-Lyme, in the County of Stafford, Boot
Manufacturer, and ARTHUR GREENWOOD, of Leeds, in the County of
York, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of May, in the year of
our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said John Keats and Arthur Greenwood, Her
special licence that we, the said John Keats and Arthur Greenwood, our
executors, administrators, and assigns, or such others as we, the said
John Keats and Arthur Greenwood, our 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 "AN IMPROVED CONSTRUCTION OF
HOOK FOR SEWING MACHINES," upon the condition (amongst others) that
we, the said John Keats and Arthur Greenwood, our executors or
administrators, by an instrument in writing under our, 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.

page_text: do hereby declare the nature of our said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the Drawing
hereunto annexed, and to the letters and figures marked thereon (that
is to say):
In sewing strong or thick leather by the sewing machine great
difficulties have hitherto been experienced in producing fine stitching
similar to that of the best hand work, it being essential not only to use
a strong waxed thread, but also a strong hook for piercing the work and
fetching up the thread of the looper.
In the accompanying Drawing the old and new constructions of hook
are illustrated in the several views and sections drawn on an enlarged
scale.
The most approved form of hook in common use (shewn in back and
side elevations at Figures 1) is made from a cylindrical rod of steel, and
it terminates in a conical point which serves to pierce the leather. The
tongue a of the hook is central or nearly so, and it is made by recessing
the cylindrical rod at the back of the tongue. This recess, termed the
throat, extends on either side of the bridge in the form of hollow
chamfers b which die off near the point of the hook. These hollow
chamfers form recesses for the reception of the looper thread which is
doubled over the bridge, but which when drawn through the leather is
nevertheless subjected to great friction. To reduce this friction on the
thread an increased diameter has been given to the stem of the hook so
as temporarily to increase the opening for the passage of the thread.
The shape of this hook necessitates the making of oval holes in the
leather, as shewn in the plan view, Fig. 2, which shows on an enlarged
scale a strip of leather as pierced by the ordinary hook. The axes of
these holes it will be seen are at an angle of about thirty degrees to the
line of feed, that is, they approach more or less near to the line of feed.
Unless therefore a long feed is given the action of the hook will be in
piercing the leather to destroy its structural strength.
The improved construction of hook is illustrated in several views.
Figures 3 and 3ª are side clevations of the hook; Fig. 4 is a plan
view of a strip of leather showing the pierced holes, the stitch and a cross
section of the hook taken in the line 1, 1, of Fig. 3; Figures 5, 6, 7,

page_text: and 8 are cross sections of the hook taken on the lines 2; 3, 4, and 5,
respectively; Figures 9 are front and back views of the hook.
This improved construction of hook is intended to reduce materially
the length of the stitches without impairing the structural strength of
the leather, and also to reduce the amount of friction put upon įthe
looper thread. In order to attain these ends we change the construction
of the hook converting the piercing point into a cutting edge, which
aproaches more or less to the form of a chisel edge with rounded
extremities, as seen best at Figures 9. This cutting edge will pierce
the leather transversely of the line of feed (say at about eighty degrees
thereto, as shewn in the plan view Fig. 4), and the tongue a of the
hook, instead of taking a central position, as in the ordinary hook (Fig. 1),
will be inclined to one side, thereby destroying the symmetry of the
book and incidentally giving a broader bridge for the thread to be drawn
over as will be clearly seen on referring to Figures 4 and 5. As the
increasing perimeter of the hook passes into the leather an oval hole
will be formed transversely of the line of feed (see the section 1, 1,
Fig. 4); and on the piercing of the next succeeding hole, supposing no
thread to be taken up by the hook, this hole would be converted from
an oval to a bean shape, as seen on the right-hand side of Fig. 4. As
the thread is drawn up by the hook in the longest axis of the hole a
minimum amount of friction will be put upon it and from the disposition
of the holes transversely to the line of feed it will be understood that
sewing like the finest quality of hand sewing may be produced. By
this construction of hook we provide that when the looper thread in
passing through the leather is least protected by the hook, the hook
shall present its full breadth, but a greatly diminished thickness to the
leather, thus allowing the leather to yield in the direction of the drag of
the thread.
It may be remarked that the tendency of the drag of the thread in
tightening up the stitches is to close the pierced holes and to give the
stitches shewn at Fig. 4.
Having now set forth the nature of the Invention of "An Improved
Construction of Hook for Sewing Machines," and explained the manner
of carrying the same into effect, we wish it to be understood that under
the above in part recited Letters Patent we claim, manufacturing the
hooks of boot sewing machines in the manner and for the purpose above

page_text: described with reference to Figures 3 to 9, inclusive of the accom-
panying Drawing.
In witness whereof, we, the said John Keats and Arthur Green-
wood, have hereunto set our hands and seals, the First day of
November, in the year of our Lord One thousand eight hundred
and seventy-five.