Year: 1886

page_text: I WILLIAM PHILIP KEESON of Langford Place, Saint Johns Wood, London in
the county of Middlesex, Printer, do hereby declare the nature of my invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
This invention relates to certain improvements in sewing machines and has for
its object to simplify and reduce the cost of manufacture of such machines.
The accompanying drawings show clearly the nature of my invention, Figure
is a side elevation of a machine, Figure 2 is a side elevation of back part of frame
showing a speed gearing in section, Figure 3 is a back end elevation of Figure 2
showing also cradle for bobbin, Figure 4 is a part plan, and Figure 5 is a part front
elevation showing detail of feed arrangement.
Similar letters refer to similar parts in all of these figures.
a is a frame of cast iron or suitable material upon which a cranked lever bb¹ is
centred at c; its shorter arm 61 engages with a grooved cam e cut in a rotary
boss el mounted on the driving shaft f. The arm b¹ may be provided with a roller d
if desired. The grooved came follows the figure of an interrupted screw of
increasing pitch, and the boss e is preferably formed concave in the direction parallel
to its axis, the radius of such concavity being advantageously made about equal to
the distance from the centre of the pivot c to either end of the boss.
Rotation
For simple speed a rotary disc h provided with a handle may be fixed to the end
of the driving shaft f as in figure 1; or, when greater speed is required a pinion g
may be fixed to the end of the driving shaft and geared in any desired ratio with
the internal teeth of a rotary disc such as h figures 2 and 3 centred in suitable
position on the back of the frame This disc may also be operated by a handle or
by the application of power to a driving pulley in the usual manner.
of the driving shaft carrying the fixed boss e¹ and grooved cam or interrupted
screw e imparts to the arm b' an uniform reciprocating rectilinear motion which is
changed in the longer arm b to a vertical reciprocating motion and any required
degree of such motion may be determined by the quickness of pitch of the inter-
rupted screw thread forming the groove e.
The outer end of arm b engages with
a slot in the needle bar i which is worked vertically in guides formed in the forked
end of the "gooseneck" part of frame a. The usual presser bar ; is arranged
along side of the needle bar provided with a spring and handle or arm for raising

page_text: or depressing it in the usual manner.
A table k is affixed to the frame in the
usual way and slotted to allow of the eccentric motion of the feed plate L. This
plate is fixed to an eccentrically centred piece l¹ figure 5 through which the driving
spindle revolves and in which it is turned eccentric and thus the required motion is
imparted to l. The driving shaft terminates in a looper m and unthreader m³.
To prevent jumping and secure uniform feed of thread instead of the bobbin being
placed vertically on a spindle as is usually the case it is placed loose on its side in a
cradle n cast or formed in the frame, and the thread passes through a hole p in the
frame to a curved wire or hook p¹ either fixed or hinged to the top of the frame:
the thread is wound around this in one or more turns according to the degree of
tension desired, and passes therefrom through hole p³ at the outer end of the frame
and thence through hole p³ at the top of the needle bar to the eye of the needle.
The drawings show the principle of the invention herein described as applied to
an ordinary plain or "tambour" stitch machine but it is obvious that with slight
modifications it is equally applicable to lock stitch or other compound stitch
machines.
+
Having now particularly described and ascertained the nature of the 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 use of a grooved cam or interrupted screw of
increasing pitch rotated with the main driving shaft actuating a cranked lever and
adapted to impart any required degree of reciprocating motion to the needle
substantially as set forth.
2. In a sewing machine the combination with a grooved cam such as is herein
described and a cranked lever of a feeding piece to which the required motion is
imparted by forming eccentric that part of the main driving shaft working within
it substantially as and for the purposes described and illustrated.
3. The cradle n for the reception of the bobbin loose on its side in combination
with the automatic tension hook as described.
4. The construction of sewing machine arranged and operating substantially as
described and represented by the accompanying drawings.
Dated this Seventeenth day of June 1886.
J. C. CHAPMAN,
Agent for Applicant.