IMPROVEMENTS IN SEWING MACHINES
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Claverhouse Alfred McCurd at the
Office of the Commissioners of, Patents, with his Petition, on the
9th October 1866.
I, CLAVERHOUSE ALFRED MCCURD, of Featherstone Street, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SEWING MACHINES," to be as follows:-
My Invention consists of various improvements in sewing machines, which
improvements may be used separately or in suitable combination, and applied
either in whole or part to various sewing machines, and are,
Firstly, a machine for forming the lock stitch, having at its lower part à
horizontal revolving shaft, to one end of which is fixed an excentric or a cam,
or its equivalent, which gives a reciprocating motion vertically to the needle
carrier, either direct or through the medium of a connecting rod. At the
other end of shaft is fixed a rotating hook for passing the loop over a bobbin,
or if for working with a shuttle a cam, or an excentric, or a crank, or a disc
with a stud on its face working in a slot or groove in or attached to a slide
carrying a shuttle is substituted in place of the rotating hook and bobbin.
Secondly, mechanism for sewing from two ordinary reels without re-winding
having at the upper part a horizontal revolving shaft. To one end of this.
shaft is fixed an excentric, or a cam, or a crank, or a disc with a stud on its
face working in a slot or groove in or attached to the needle-slide. At the
other end of the shaft is fixed a double cam working in a fork at the upper

page_text: end of a vertical lever to which a rocking motion is given and communicated
to a horizontal lever (below the bed of machine) having an eye-pointed looper
at its end; a loop opener receives its motion from the horizontal lever by
means of a stud working in a slot. The looper is rendered accessible by
means of a readily removable table plate (on which the fabric is placed for
sewing), this plate is held in its place by steady pins fitting into corresponding
holes, the plate being sufficiently heavy to hold itself down by its weight and
retain the steady pins in their holes, by these means dispensing with the use of
fixing screws.
eye
Thirdly, a method of rendering the stitch in chain-stitch machines secure,
and is applicable to chain-stitch machines in general. To effect this the looper
has an eye at its thick part or base (away from the point) which
carries a
thread, so that the needle having an eye near its point carrying a thread will
at its next descent take off its last loop (which loop has been detained by the
looper) and also take off the thread the looper carries, namely, the thread
passing through the eye of the looper.
.
Fourthly, a tension either fixed or adjustable for the lower bobbin or spool
of lock-stitch machines of that kind having a bobbin or spool at the under
part instead of a shuttle, which tension consists of a sliding shaft-kept from
revolving by having a keyway cut in it lengthwise (or its equivalent). At
the inside end of this shaft is a flange or a disc for exerting pressure against
the spool or bobbin; a helical spring coils round the shaft and presses at one
end against the bearing the shaft works in and at the other against a nut, which
is either fixed or working on a screw cut on part of the shaft.
Fifthly, arrangement of machinery for producing the lock stitch by the aid
of a shuttle consisting (with other parts) of two revolving shafts;
one of which
is vertical and the other horizontal, geared together by bevelled wheels. At
the other end of the shafts to that having the wheels is a cam or an excentric,
or a crank, or a dise with a stud on its face working in a slot or groove, in or
attached to a slide, and giving a reciprocating motion thereto, the upper slide
carrying the needle and the lower one the shuttle.
Sixthly, a modification of the preceeding with certain alterations, consisting
(with other parts) of three revolving shafts, two of which shafts are horizontal
and the third vertical, geared together as in the preceeding by bevelled wheels.
At the other end of the upper horizontal shaft to that occupied by the wheel
is a cam, or an excentric, or a crank, or a disc with a stud on its face working
in a slot or groove in or attached to the needle slide, and at the same end
of the lower shaft is the arrangement described under "firstly" for working
either the shuttle or the bobbin and hook.

page_text: Seventhly, another arrangement of machinery for producing the lock stitch
by the aid of the shuttle. At the upper part is a horizontal revolving shaft,
having at its left-hand end a cam, or an excentric, or a crank, or a disc with
a stud on its face working in a slot. or groove in or attached to the needle
slide. At the other end of the shaft is a cam, or an excentric, or a crank, or
a disc with a stud or a ball on its face from which a connecting rod descends
to one of the arms of a two-arm lever working in bracket bearings, from
the other arm of this lever another rod communicates motion to the
shuttle.
Eighthly, mechanism for producing the lock stitch or the double lock
stitch. To produce the single lock stitch the needle after every descent has
the under thread once passed through its loop, it then rises and the feed
comes into operation and moves the fabric sufficient to form the length of
stitch. To form the double lock stitch the needle pierces the fabric and then
recedes, as in forming the single lock stitch, but with 'this difference, that
the fabric is not fed until the needle has again pierced the fabric at the same
spot as before, when the under thread is again passed through its loop, and
in drawing this second loop tight the two stitches made at the same point
of the fabric merge into one and form the double lock stitch, and the fabric
is then fed to produce the length of stitch. Two horizontal revolving shafts
(one at the upper and the other at the lower part of the casting) are geared
together by two spur wheels, the spur wheel on the lower shaft having double
the number of teeth to that on the upper, so that one revolution of the lower
shaft makes the upper, shaft revolve twice (which can be effected by many
other mechanical arrangements). At the other end of the upper shaft is a
cam, or an excentric, or a crank, or a disc with a stud on its face working in
a slot or groove in or attached to the needle slide, and at the same end of
the lower shaft are two hooks placed opposite to each other for passing the
loops of the needle thread over a bobbin.
Ninthly, an improved feed, which dispenses with the use of springs in this
part of sewing machines, and consequently requiring but a small expenditure
of power: At one end of a revolving shaft is a cam, or an excentric, or a
crank, or a disc with a stud on its face working. in a slot or groove in or
attached to the needle slide. At the back of the disc is an oval cam or au
excentric which acts against the frame of bearing in which the needle slide
works, and gives it a motion laterally after the needle has pierced the fabric,
which motion carries with it the needle and fabric, and so gives the feed.
When the needle is next raised and out of the fabric the cam or excentric-
acting against the end of the screw for regulating the length of stitch gives

page_text: a lateral motion in the reverse direction, so that the needle at its next descent
enters a fresh part of the fabric, the said needle receiving in addition to its
reciprocating motion a lateral motion.
Tenthly, arrangement of machinery for forming the lock stitch having two
horizontal shafts, both of which revolve at the same velocity, namely, one at
the upper part of the machine and the other at the lower. At the right-hand
end of each shaft is fixed a spur wheel, both spur wheels containing the same
number of teeth, motion being communicated from one spur wheel to the
other by means of an intermediate spur wheel fixed to a shaft which revolves
in its bearing, through which it projects, forming a mandrel on which the
bobbin is placed for winding. At the left-hand end of the upper shaft is a
cam, or an excentric, or a crank, or a disc with a stud on its face working in
a slot or groove in or attached to the needle slide. At the left-hand end of
the lower shaft is a hook revolving round. a bobbin. The three spur wheels
can' be dispensed with by substituting and fixing to the same end of lower
Shaft a disc with a stud on its face (or its equivalent) from which a connecting
rod ascends to an arm fixed to upper shaft, to which it gives a rocking motion
of about 150 degrees, or a coupling rod ascending from the stud on disc of
lower shaft, and working a corresponding stud on the face of a small fly wheel
fixed on the end of the upper shaft, the fly wheel serving to carry it over the
dead points and cause it to revolve regularly.
Eleventhly, arrangement of machinery adapted for a hand sewing machine
for producing the lock stitch having a horizontal revolving shaft at its lower
part. At the left-hand end of this shaft is a hook revolving round a bobbin,
or the arrangement previously described under "firstly " for working a shuttle,
and at the other end of this shaft is fixed a spur wheel gearing into another
spur wheel placed above it, the upper spur wheel containing double the
number of teeth of the lower. On the inside face of the upper wheel is a
groove in which a ball friction roller at the right-hand end of a lever works,
and receives a rocking motion, and at the other end of this lever is a short
slot in which a stud attached to needle slide acts, the rocking motion of the
lever giving a reciprocating motion vertically to the slide carrying the needle.
A curved needle can be used in this arrangement by attaching it to the end
of lever and dispensing with the needle slide.
Lastly, modifications of the preceeding having at the lower part a horizontal
revolving shaft with a rotating hook and bobbin at one end and a pulley with
a groove on its face at the other, or instead of the hook and bobbin the
arrangement for working the shuttle described under "firstly." At the upper
part is an arm or lever carrying at the left-hand end a curved needle, or a

page_text: straight needle can be worked by cutting a slot in the end of lever (as
described in the preceeding), through which slot a stud fixed to a vertical
needle slide acts. At the right-hand end of lever is a ball friction roller
working in the groove cut in pulley, or instead of the rocking motion being
given to the lever by means of the groove in pulley an excentric can be fixed
on the driving-shaft, and in place of the friction-roller.a. fixed ball substituted,
or an excentric, or a cam, or its equivalent working in the end of arm or lever.
In sewing machines constructed according to these improvements the
fabric can be fed by any ordinary feed of a suitable character without being
confined to any particular method.