IMPROVEMENTS IN SEWING-MACHINES
Year: 1885

page_text: I, JOHN CHARMBURY, of Percy Cottage, Buccleugh Road, West Dulwich, in the
County of Surrey, Engineer, do hereby declare the nature of my invention for
"IMPROVEMENTS IN SEWING-MACHINES to be as follows:-
This invention relates to sewing-machines chiefly designed for sewing binding
material upon hat-linings or sweat-leathers or for other purposes where the thread
has to be passed around the edge of the work.
The main feature of the said invention is the provision of means whereby the
loop of the needle-thread formed during one down-stroke of the needle will be
transferred from the lower to the upper side of the material being sewed, so that
the thread can be passed through the same in the succeeding down-stroke of the
needle, and the operation termed overcasting can thus be effected by a sewing-
machine.
For this purpose I usually employ a book to which motion is imparted in such
a manner that it will enter the loop of the needle-thread beneath the needle-plate
or work-support, and will transfer the said thread from the lower to the upper side
of the material so that the needle, in making the succeeding stitch, will enter the
said loop above the work.
This hook enters the loop of the needle-thread, when it is in its lowest position
and withdraws from the said loop when it is in its highest position, and without
the necessity for any backward movement or reversal of motion of the machine.
The said hook has a combined rotary and reciprocating motion imparted to it by
suitable cams and levers, operated by the main shaft of the sewing-machine. It is
formed with a notch or recess across which the thread is stretched, when the hook
is in its highest position, so that the needle can easily enter the loop of the thread.
The mechanism which I prefer to employ for imparting motion to the said hook
is constructed as follows, that is to say-The said hook forms the extremity of the
upper arm of a double-armed lever, which is carried by a cam or excentric fitting,
with a capability of free rotation, in the boss of the said lever. This cam or
excentric forms part of a block or piece mounted loosely upon the main shaft.
TDi Q71

page_text: This piece is capable of sliding longitudinally to and fro upon the said shaft, but
is compelled to turn therewith by a pin or driver fixed on the shaft. The lower
arm of the aforesaid lever is forked and engages with a pin or stud fixed in a
sliding rod or bar, which is coupled at one end to an arm or lever fixed on a shaft
carried in a suitable bearing. On this shaft is also fixed a lever or arm bearing
on a cam which also forms part of the aforesaid sliding block or piece. The other
end of the said sliding bar or rod is acted upon by a spring, which tends to press
it towards the arm or lever to which it is coupled.
The said sliding block or piece is formed with a cam-groove, into which projects
a pin or stud fixed in the frame of the machine, so that the rotation of the main
shaft and the said block or piece will cause the reciprocating movement of the said
sliding block or piece and of the aforesaid hook, the rotation of which is effected
by means of the aforesaid cam or excentric.
The feeding of the material through the machine is effected by means of two
serrated or roughened wheels, one above, and the other below, the work. The
lower wheel is arranged to be intermittently rotated by an arm or lever carrying
a pawl engaging with teeth on the said wheel, which arm is acted upon by an arm
or lever carried by one end of a shaft. The other end of this shaft carries another
arm or lever arranged to be acted upon by a cam fixed on the main shaft.
Suitable means are, moreover, provided for regulating the feed.
It is obvious that other means than those above described can be employed for
transferring the loop of the needle-thread from the lower to the upper side of the
material for the purpose above specified.
HASELTINE, LAKE & Co.,
For the Applicant.

page_text: JOHN CHARMBURY of Percy Cottage, Buccleugh Road, West Dulwich, Engineer,
(a communication from Henry Charmbury, United States) do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
The object of this Invention is to make an "over-stitch" machine that will be
more reliable in its action, of increased simplicity of construction, less liable to get
out of order and one more rapid in its movements.
It consists in the arrangements and combinations of parts substantially as will
be hereinafter set forth and finally be embodied in the claim.
Referring to the accompanying drawings, comprised in two sheets, in which
similar letters of reference indicate like parts in each of the several figures;
figure 1, is a front elevation of the device; figures 2, and 3, detail views of a hook
of peculiar construction adapted to take the thread from the underside of the
material worked upon and draw it over the edge of the material; figure 4, is a
plan of the mechanism for operating the said hook; figure 5, is a sectional view
taken through line x, figure 4; and figure 6, is an end view of said hook operating
mechanism taken in the direction indicated by the arrow from line y.
In carrying out the invention I arrange in suitable bearings upon the frame or
bed-plate a, a driving shaft b, which is operated by the pulley c, in any ordinary.
or appropriate manner.
Upon said shaft is arranged a series of cams and other mechanism for giving
proper motion to the hook.
Of said book-operating mechanism, d, is a collar, which is rigidly secured to the
shaft and has a lateral projection or projections d', upon which a compound came,
slides laterally, influenced by a stationary pin, projection, or roller, f, figure 5
working in a curved or an irregular peripheral cam-groove, g. This lateral
movement of the cam on the shaft is imparted to the hook and is useful in that it
causes said hook to pass under the material to catch the needle-thread, to bring it
back again to clear the edge of the material and to project it toward the needle
over the upper side when other subsequently-mentioned mechanism causes the book
to move upward and in a lateral direction toward the operator.
Rigidly secured to the cam and sliding with the same is arranged an excentric, h,
provided with a strap, i, to which the hook k, is secured and from which a depending
slotted arm, 1, projects.
Said excentric arm, l, has a bearing on a pin m, and gives to the excentric strap
and hook secured thereon a vertical and vibratory motion, or in other words the
hook would be caused to describe an elipse if not acted on by the laterally moving
cam which causes it to deflect from a regular course both above and below the edge
of the material.

page_text: To cause the hook to remain stationary for a moment when presenting the loop
to the needle on the upper side of the material preparatory to releasing or with-
drawing from said loop and passing downward and under said material to take up
another loop, I form a cam projection n, on the compound cam which engages with
a lever, o, p, fulcrumed on the stud q. The opposite end of the lever from that
engaging the cam projection is connected with a bar which carries the stud m,
belorementioned.
When the hook in its movement with the thread loop is in position to receive
the needle as beforementioned, the cam projection, o, acts on the lever p, q, and
causes the pin to move laterally and with it the arm of the excentric strap.
This movement counteracts the action of the excentric so that the hook remains
stationary while the needle descends through the loop. The cam projection having
passed the lever, the spring & throws said lever forward into its normal position
while the cam groove g, and roller f, coäct to cause the hook to withdraw and
descend beneath the materia!.
The hook extremity is peculiar being provided with a hook projection, t, which
catches the thread on the underside of the material, and forming a loop, brings it
up over the edge of the material.
To hold the thread out from the face of the hook when presenting it to the
needle so that the said needle can freely enter between the thread and said face,
I form a second projection u, with a needle notch, v, between it and the said hook.
Said projection u, euters the loop and holds the thread apart so that the needle will
not hug the hook so closely as to endanger the same.
A slight shoulder in the cam-groove causes the hook to move backward from the
needle, freeing said needle from the notch before moving in its regular course.
By the construction and arrangement of mechanism above described I am enabled
to use a hook with a short shauk as compared with those heretofore used. Vibration
of said shank, occasioned by the draught of the thread thereon and from other
causes, is thus materially reduced or entirely overcome and interference of parts is
thereby prevented.
The action of the hook under the influence of the above mentioned mechanism
substantially as follows:-
The hook, beneath the material engages with or catches the needle thread and
draws it from beneath the material, upward and toward the operator. It then
passes over the edge of the said material backward (or from the operator) toward
the needle.
When the notch in the hook arrives at the path of the needle, it stops for a
moment and the needle descends through the open loop held open by the pro-
jection u. The hook then moves from the needle freeing the same from the notch
and finally moves from the operator downward and again under the material to
take up another loop.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed I declare that what
I claim is
1. In a sewing machine, the combination with the needle and a driving shaft, of
a hook, and excentric, a shaft carrying said hook, a can actuating said strap and
hook, and revolving with and sliding on said shaft, substantially as set forth.
2. In a sewing machine the combination with the needle and shaft b, of a sliding
excentric carried by said shaft, an excentric strap and a hook secured on said strap
and mechanism substantially as described, to cause said excentric to move longi-
tudinally on said shaft, as set forth.
3. In combination with a driving shaft, b, a cam sliding laterally upon and
revolving with the shaft, an excentric and a strap having the hook secured thereon
and the needle, all said parts being arranged and operating substantially as and for
the purposes set forth.

page_text: 4. In combination in a sewing machine with the driving shaft and needle, the
cam sliding on and revolving with said shaft, the excentric, the strap having the
slotted arm and hook, the cam projection, the lever and bar having the pin acting
as a bearing for said screw, all said parts being arranged and operating substan-
tially as set forth and shown.
5. In a sewing machine, the combination with the needle, the cloth plate and
the driving shaft, of a hook, and excentric, or its equivalent adapted to cause the
said hook to move reciprocally above and below the said cloth plate, and mechanism
substantially as described adapted to move said hook longitudinally with respect to
the said shaft, all said parts being arranged and operating substantially as and for
the purpose set forth.