Improvements in Sewing Machines for Producing Ornamental Stitching.
Year: 1898

page_text: Date of Application, 17th Aug., 1898-Accepted, 12th Nov., 1898
COMPLETE SPECIFICATION.
Improvements in Sewing Machines for Producing Ornamental
Stitching.
I, DONALD NOBLE, of The Wheeler Wilson Manufacturing Co., of 11 to 21,
Paul Street, Finsbury, in the County of London, Engineer, 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 state-
ment:
This invention relates to devices in sewing machines for producing ornamental
stitching chiefly in machines having two threads underneath the work plate
and one or two threads above the work plate, and the said invention has for
its chief object improved means for the production of an ornamental stitch or
pattern on the face of the work without long stitches at the back, thereby
economising the thread. In some instances the invention is carried out by the
use of one thread only underneath the work plate.
The chief feature of my improved apparatus is a compound needle bar so
constructed and arranged that the part of the needle bar which carries the needle
or needles is capable of oscillation for a purpose that will hereinafter appear.
The said oscillatory part of the bar extends longitudinally through the tubular
non-oscillatory part and is constructed to rise and fall with the latter which
is actuated in the usual manner to effect the stitching. The oscillation of the
inner bar is effected by means of a cam or equivalent device acting through
a segment wheel which gears with a pinion fixed to or formed integrally with
a sleeve situated at the top of the needle bar. The said sleeve engages by a pin
and slot with the inner bar so as to impart its oscillatory movement to the
said bar while allowing the bar to rise and fall. The needle is arranged éccen-
trically in the needle bar and its position with respect to the work plate is there-
fore shifted by the oscillations of the bar so that it engages first with one lower
thread and then with the other lower thread, and produces a zigzag stitch at
the top when the work is fed in the ordinary manner. Flowered work and
designs are made by moving the fabric about as required by hand, whereby
long stitches may be made on the face of the fabric with short stitches at the
back, thus economising the thread.
Referring to the accompanying drawings,
Fig. 1 is a side elevation partly in section of so much of a sewing machine
with my improvements attached as is necessary to illustrate my invention, and
Fig. 2 is a plan of the same.
A is the needle bar, B is the machine arm, C is the work plate or throat
plate, D, D are two hooks of the usual Wheeler and Wilson pattern, containing
the spools, and E is the rotary shaft for actuating the needle bar through the
connecting link F in the usual manner.
The needle bar is a compound bar comprising an outer tubular non-oscillating
part a and an inner oscillating part a extending through the tubular part at
both ends and carrying the needle clamp G in which the needle is set eccentric-

page_text: ally as indicated. A shoulder on the part a abuts against the lower end of
the tubular part a', while a collar a secured on the upper end of the part a
by an adjusting screw a abuts against the upper end of the tubular part a¹,
so that the inner bar a³ cannot move endwise in the tubular part a but it can
turn freely therein. Any slack is taken up by adjusting the screw a. The
oscillating part of the needle bar is driven through a sleeve or tubular cap H
which surrounds the upper end of the needle bar and takes a bearing in the
machine arm. It is free to rotate in its bearing and is held in place by a pin
or screw which projects into an annular slot in the cap. The said cap is
slotted longitudinally at h² and into this slot there projects a pin or screw K
which is passed through the collar at and fixed in oscillatory part a² of the
needle bar. L is a pinion fixed on or formed integrally with the tubular cap H,
and gearing with a segment wheel M centered at m. This segment wheel is
actuated by a link N connected at one end at m² to the segment wheel, and at
the other end to a quadrant P pivoted at P¹. This quadrant is actuated by
a switch cam Q with which the follower p carried by the quadrant engages.
The cam Q is fixed on the rotary driving shaft E.. The end of the link N is
adjustable in a slot p' in the quadrant P towards and away from the pivot
centre P whereby the throw of the link N and consequently the extent of move-
ment of the segment wheel M can be regulated to suit requirements..
By the above described means the inner bar a carrying the needle is oscil-
lated, and the needle is thus caused to descend alternately through the two
holes of the work plate and to engage first with one and then with the other
of the threads underneath the work plate. In this way a zigzag stitch is pro-
duced on the face of the work, when the latter is fed in the ordinary manner.
When two needles are used, a double or crossed zigzag stitch is produced, or by.
oscillating the needle bar through a whole revolution, a crossing and inter-
locking of the threads at the top may be effected.
When making designs or flowered work, the fabric is moved about as required
by hand, between successive stitches, and in this way fancy or flowered stitching
is produced with long stitches at the top or face of the fabric, and short stitches
at the back.
When only one lower thread is used, a slotted needle hole is provided in the
work plate instead of two separate holes as above described.
By setting the link N back above the centre P¹ of the quadrant pivot, the
oscillation of the needle bar can be prevented, and the machine can then be
worked as an ordinary machine.
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. The compound needle bar having an oscillating part, and a non-oscillating
part, with one or two needles set eccentrically therein, substantially as, and
for the purposes, specified.
2. The means for oscillating the inner part of the needle bar, substantially.
as described.
3. A sewing machine provided with the devices substantially as described
with reference to the accompanying drawings, for the purposes specified.
T
1211
1
1000
GEORGE HARRISON,
35, Therapia Road, Honor Oak, London,
Agent for the Applicant.