Year: 1888

page_text: Date of Application, 14th Jan., 1888
Specification Accepted, 17th Feb., 1888
Fig. 4 a section on the line y z of Fig. 1.
Fig. 5 shews the machine as viewed from above; the other Figures are details.
The machine is built up upon the base plate B provided with the usual bracket
arm A. The base plate B has, at its front end, a projecting piece b, upon which the
sewing plate is screwed. The sewing plate is omitted from the drawing in order that
the underlying parts may be seen more clearly.
The driving of the entire mechanisms is effected from the main driving shaft a,
Fig. 1, which has its bearings, at front, in the projection b, and at the rear in the
bracket arm A. At the rear end, outside the arm A, the shaft a carries the driving
pulley a¹ and an excentric a², which operates the needle bar i, the thread regulator,
and the automatic thread tension o, which in itself is already known. In front of the
arm A, the shaft a carries a grooved cam a³, and three excentrics a¹ a³ a*..
The excentrics at a serve to operate the feed dog d, which is carried by an arm d'
embracing the excentric a³. It is by the action of the excentric a³ that the feed dog
is lifted to its work, and by the excentric at that the traverse motions of the feed
Price 1171

page_text: dog are effected. The arm d' projects from a strap piece d*, which connects, by
means of an axle d², with the frame d³, in such a manner as to be free to rock
thereon.
The frame d³ has its bearings in the base plate B, and by means of an axle d',
which constitutes its fulcrum, it enabled to rock under the action of the excentric at..
One side of the frame d³ is slotted, as at d³, to receive an adjustable pin, which
connects to the frame the excentric rod d of the excentric a*.
The higher the point of attachment of the excentric rod de is set in the slot d³, the
less will be the feed of the work and the length of the stitches.
This feeding action is not in itself new, but what is new is, that the excentric a*
only pushes forward the work, whilst the excentric a³ only raises and lowers the
work.
In the guide slot feeds hitherto known, the lifting and the pushing forward of the
work proceed from a single excentric; in these cases, however, because, under all
circumstances the raising and lowering of the presser must be at least 31mm in
extent, stitches of less than 1/m cannot be formed, without allowing the slot to
extend high above the sewing plate, which would, on the other hand, hinder the
feeding forward of the work.
The excentric a is here only excentric to the extent of 1/m; it is therefore clear
that when the excentric rod aº (Fig. 3) is screwed fast at the level of the axis of the
excentric shaft, the arm d', and the feed dog d in connection therewith, will only push
forward the work to be sewn to the extent of 1/m. The work will however be
pushed forward more than 1/m when the attachment of the excentric rod dⓇ is below
the level of the axis of the excentric shaft, as shewn at Fig. 3, but less than 1m/m when
the excentric rod is fastened above that level. The excentric a³ will, however, even
in the case of the thickest work, raise and lower sufficiently the arm d¹ carrying the
feed dog d, because a³ has a throw of 31/m. From this it results, that knitted goods,
in which each loop of a row or line should be operated on by the needle, could not be
sewn if two distinct excentrics were not used to secure the sufficient raising and
pushing forward of the work to be sewn.
The grooved cam a³, and an excentric a, both on the shaft a, serve to give motion
to a hook-shaped looper e, which is designed to lap the loops of the needle thread
over the edge of the work, and present the opened loop to the needle on its next
descent, for the securing of the loop by the insertion of a second loop therein.
This looper receives, by means of the parts hereafter mentioned, the requisite
motions for taking up the loop of the needle thread, laying it over the edge of tho
work as the work is fed forward, following its advance to present the opened loop to
the needle on its next descent; then, when the needle has caught the loop, freeing
itself from the loop, and taking up its position below the work, to repeat these
operations.
To this end the looper e is pivotted to a rod e¹ (see Fig. 3, and shown also detached
in two views at Figs. 6). On this rod the looper is capable of rocking, and the rod
itself, being fitted on a sleeve e², is capable of turning on its axis, but not capable
of lateral motion. The sleeve e² is free to rock upon a pivot pin e³ secured to the
base plate, and is provided with a longitudinal slot, into which takes the pin e of
a rocking arm e', also secured to the base plate. This arm e' receives an up and
down motion from the excentric rod e8 of the excentric aº, and communicates an up
and down motion, by means of the sleeve e², to the looper e.
In order to impart to the looper its other movements, it is connected by means of
a coupling pin e' with a bent arm e¹o, which is pivotted to one end of a rock lever e",
which swings horizontally upon a centre e¹ carried by a rocking arm e". The other
end of the lever el carries (adjustably) in a sleeve, a pin e¹³, which is secured upon
a rocking arm e¹ by means of a conical pin e¹. The rocking arm e¹ is pivotted
to a lug on the base plate B, and is actuated through a bowl, which it carries,
by the cam groove a formed in the side of the cam a³-Thus, as the cam (see
Figs. 5 and 1) is rotated, the rocking movement given to the arm e¹³ will be
communicated, by means of the pin e", rock lever e", and arm e¹ to the looper <.

page_text: The forward and backward motion is communicated to the looper by the rocking
arm e¹, which is secured to the base plate by the pivot pin e (Fig. 5), upon
which it turns. This rocking arm, by means of a bowl e", which takes into a
groove a formed in the periphery of the cam a³, receives a rocking motion, and,
through the lever e¹¹ (which it carries), and the bent arm e¹0, transmits the same
to the looper e.
Referring now to Figs. 1, 2, 3, and 4, motion is communicated from the
excentric a², through a rod f (Figs. 1 and 2) and a crank g, to a shaft h,
which, by means of a second crank g and a link g2, will set the needle bar i in
motion.
This needle bar i works up and down in guides, as usual, in the head of the
bracket arm of the machine, and carries at its lower end the needle.
In the head of the bracket arm also slides up and down the presser bar k, the
foot of which is provided with a guide for the work. The presser bar is con-
nected, by means of a clamp piece k² (Figs. 3 and 4), arm k³, pin ka, arm k³, and
and shaft ko, with a thread regulator k, which arrangement forms the subject of
a separate application for a patent bearing even date herewith, and need not therefore
be here further described.
The presser bar is also provided with a pin 48 (Fig. 3), the front end of which
carries an excentric provided with a handle, and the rear end of which is
screwed into another pin ko, arranged in a recess of the head of the bracket arm.
By means of a spiral spring k", also arranged within this recess, and surrounding
the pin ko, the presser bar is continually pressed in a downward direction.
turning the excentric k³, the periphery of which presses against the part A2 of the
head of the bracket arm, the presser will be raised out of work, as usual.
On
The combined action of the needle and the looper, and the formation of the stitch
thereby effected, is shewn in Figs. 7 to 12, which Figures represent each position
of the several working parts in front and side views. Figs. 7 shew the needle raised
from its lowest position, and forming a loop under the work, to be caught by the
looper.
As the needle rises to clear the work, the looper moves rearwards, or from the front,
and upwards (see Figs. 8); it then goes forwards again (see Figs. 9), until it comes
in line with the needle (see Figs. 10), and has laid the loop over the edge of the work.
The feed of the work now takes place, the looper meanwhile moving with the work,
and sideways to the right, sinking a little at the same time to the position shewn at
Figs. 11, when the needle in its descent passes through and secures the loop.-This
being effected, the looper moves rearwards around the needle to the position of Figs. 12,
and then sideways to the left, and downwards, whereby it withdraws from the loop.
The looper then returns again to its original starting position, Figs. 7, in order to take
hold of the next succeeding loop formed by the needle, to widen the same, and to
present the same, above the work, to the descending needle, as before.
The tightening of the stitch is effected partly by the feed of the work, and partly
through the drawing up of the last formed loop by the looper.
In order that, on the drawing up of the loop by the looper, the work shall not be
tipped up on one side, the sewing plate is provided with a projection D, Figs. 13,
situate at the back of the stitch hole of the sewing plate, around which the looper lays
the loop as it moves upwards and forwards.-Figs. 7 to 12 also shew the projection D,
and its use in retaining the loop.
Fig. 14 shews, on an enlarged scale, a complete stitch applied to a piece of work.
I may remark that if the looper is pierced at its point to receive a thread from a
second bobbin, the ornamental stitch shown at Fig. 15 can be produced.
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 application to over edge sewing machines, of a looper actuated in the manner
and for the purpose above described with reference to the drawings.

page_text: 2. The use, in over edge sewing machines, of the projection D, situate at the back
of the stitch hole of the stitch plate, for the purpose above set forth.
3. The arrangement of adjustable feed with two excentrics, the one for raising and
the other for advancing and retiring the feed dog, to ensure a proper bite of the
work, and enable stitches of one, or less than one, millimeter in length to be
formed.