Improvements relating to Sewing Machines.
Year: 1892

page_text: Date of Application, 11th June, 1892-Accepted, 30th July, 1892
COMPLETE SPECIFICATION.
Improvements relating to Sewing Machines.
I, CHARLES BRANSTON HUNT, of The Branston Two Reel Sewing Machine
Company Limited, 59 Holborn Viaduct, City of London, Manufacturer, 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:-
This invention is two-fold, and relates to certain detail arrangements of
mechanism for attachment to sewing machines.
:-
First To appliances operatable from the upper shaft for alternately gripping
and regulating the drag on the thread to the needle.
Secondly To gutter shaped or slotted guide for effecting the proper
movement of the hook or looper working from the axis of a crank pin for engaging
the loop of the needle thread, and for automatically relieving itself of the loop, and
leaving it free to be drawn back by the "take up.'
According to the first part of the invention, I affix a combined thread gripper
and tension apparatus on the arm of a machine, and by a cam on the upper shaft,
and by a spring cause a rod to bear upon it, which spring when compressed by the
nose of the cam, acting on a rod enables the grip to be removed and gives freedom
for the ordinary tension appliance on the upper part of the rod, this permits the
thread to be drawn from the reel, but when the rod is down and under pressure of
its spring, the thread is held tightly, thus, there is no loose thread between the
tension and the needle, except that required for the sewing operation.
According to the second part of my invention, which is chiefly for use with a
two reel sewing machine. I employ a gutter shaped or slotted guide under the
bedplate, said guide being connected adjustably to an arm projecting from the front
bearer block of the under shaft, this guide forms a race for a bowl to ride in, the
bowl being at one end of a metal strip, the other end of which carries the looper
hook by a pin having free axial motion in a crank affixed to the front end of the
under shaft. By this arrangement, the looper hook can be "sett" for its nose to
enter as it is passing the needle, and engage the loop of upper thread, then to point
downwardly and draw the upper thread from the "take up," the loop gradually
sliding into the neck of the fooper while being so carried downwards, around and
under the lower reel, the looper nose then gradually points upwardly and gets into
position to slide off and away from the loop and leave it, said loop being now free
for the "take up" to draw in and make the stitch.
My invention will be clearly understood by reference to the annexed drawings
and I will describe the two novel features as applied to work in unison in a two
reel sewing machine.
Figure 1 part sectional longitudinal elevation of the arm of a sewing machine.
Figure 2 transverse section of same on line 1. 2.
Figure 3 elevation of front bearer showing position of looper when engaging in
loop of upper thread.
Figure 4 similar elevation with loop opening to pass round lower reel.
Figure 5 elevation with looper further advanced.
Figure 6 elevation with looper at half circle position.
Figure 7 elevation with looper in position to release the loop.
Figure 8 elevation with looper withdrawn from loop by canting of looper.
Figure 9 elevation representing loop partly drawn by "take up."
Figure 10 side elevation of looper and its fixings.
Figure 11 plan of looper and fixings.
Referring to Figures 1 and 2, A is arm of machine B upper shaft, C cam thereon,
D bowl riding on cam. E rod. F pressure spring acting against shoulder of

page_text: pedestal casing G and on guide H. I light or tension spring on rod E surmounted
by loose discs J, K, like usual tension appliance when spring F is compressed by
cam C, the thread being then free to be drawn upon from the reel according to
the pull of the "take up which in practice only pulls sufficient for the
succeeding stitch in order that no strain be put upon the needle in its next descent
through the fabric.
"
When the cam C has passed the bowl, the spring F forces the rod E down-
wards, and the two discs J, K, are pressed into close contact and rigidly fix the
thread between them until the cam raises the rod again to free the discs for a
fresh supply of thread to be drawn from the reel L. M is guide pin to lead the
thread into and between the grip and tension discs.
The apparatus thus described and operated from the upper shaft is applicable
to all kinds of lockstitch sewing machines, whether provided with shuttles, spools,
loopers, or other systems for effecting the lock; and the special importance of
said apparatus is its method of operating the alternate grip and tension on the
thread from a cam on the upper shaft of a sewing machine.
The second part of my invention, as shown on the second sheet of drawings, is
for the employment of a gutter shaped guide, or it may be a slotted guide N under
the bedplate P, it is affixed to the bearer at the required angle by the screw
pin R passed into the projecting socket S. The bowl or roller T is on one end of
the strip U, the collar V of which is secured to the stem of the looper W, this
having free oscillatory motion in the crank arm X on end of under shaft Y to give
a circular travel to the looper stem, as indicated by the broken line a, a, the looper
having an additional motion for engaging the loop and for disengaging it from
movement of the strip U and the guide N.
By this feature of my invention, the looper is available for under reels or spools
arranged vertically or horizontally in the cage or holder, and by the arrangement
of the parts shown, a very short needle can be employed, which is an advantage in
a sewing machine because it obviates the tendency of the needle to yield, or get out
of shape in entering and passing through the fabric.
c is the lower reel and holder, and d the lower thread.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. The combined tension and grip appliance before referred to and shown at
Figures 1 and 2 of the annexed drawings operated by cam on upper shaft,
substantially as set forth.
2. Providing the upper shaft of a sewing machine with a cam for removing the
grip from upper thread and permitting of ordinary tension for slip of thread
from apparatus fixed on machine arm, said apparatus being constructed and acting
for both operations, as described and arranged substantially as shown.
3. The employment of a gutter shaped adjustable guide or its equivalent under
the bed plate of a spool or a two reel sewing machine for governing the reciprocating
action of a strip, whereby the hook or looper moving in a circular path from
crank of under shaft is caused to present its point to engage the loop of upper
thread, and then to turn on axis of crank to release the loop after drawing the
loop the required distance around the lower reel and its holder, as set forth.
4. As an attachment to a sewing machine of the spool or the two reel kinds, a
straight race guide for strip to move in and determine the rocking motion of hook
or looper working in a circular path from the axis of crank on under shaft, as and
for the purposes set forth.
Dad thin with
T1000
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said C. B. Hunt.