IMPROVEMENTS IN LOCK STITCH SEWING MACHINES
Year: 1884

page_text: I, EMIL CAPITAINE of 89 Chancery Lane in the County of Middlesex, Patent
Agent, do hereby declare, the nature of the said Invention for "IMPROVEMENTS IN
LOCK STITCH SEWING MACHINES" and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement:-
These improvements in sewing machines which are hereinafter described with
reference to the accompanying Sheet of illustrative Drawings, are effected in the
thread operating mechanism, and relate:-
-
Firstly, To a particular construction of rotating bobbin holder A.
Secondly, To effecting the motion of the bobbin holder A by means of a
carrier B.
Thirdly, To the arrangement of the bobbin holder A with reference to, and in
conjunction with the carrier B.
The bobbin for the bottom thread is fitted in the bobbin holder A as shewn in
cross section in Fig. 7. and in elevation in Figs. 6 and 8. The bobbin holder A
rotates within, an open frame E which as a guide for it, and receives its motion
from the carrier B, by reason of the pins b, b, arranged in the latter (Figs. 1 and 5)
alternately engaging in the recesses a, a, of the bobbin holder A (Fig. 7). The
formation of the stitch of the thread necessitates the setting in motion of the
rotating bobbin holder at its lower part only, no connection of the upper part of
the bobbin holder A taking place with its driving mechanism, otherwise, one of the
pins b would pass into the loop in course of formation (see Figs. 2 and 4).
Therefore in order that the transfer of motion from the carrier B (Figs. 1 and 5)
shall take place only at the lower part of the bobbin holder A, the casing E
(Figs. 1 and 5) is placed at an angle to the carrier so that the pins b, b, shall engage
in the lowermost of the recesses a, a; but having proceeded upwards they again
separate from the bobbin holder A, and in this manner make room for the
completion of the loop.
The carrier motion is obtained from the shaft f, being transferred to the carrier B
by means of the toothed wheels c, and d, (Fig. 5) the former being fixed on the
shaft f, and the latter on the boss of the carrier disc. The number of teeth in the

page_text: two wheels is in the proportion of 1:2 so that the bobbin holder A performs one
revolution to two revolutions of the shaft f, and accordingly the needle goes twice
up and down (Figs. 2 and 4) during one revolution of the bobbin holder.-
The mechanism necessary for the before described working arrangement, consists
as already stated of the bobbin holder A and carrier B which are shewn in detail
in Figs. 5 to 8. The bobbin holder A consists substantially of a casing which, at
opposite points is formed with two engaging hooks 1, 1, for catching hold of and
carrying along the thread; within the casing is fitted the spindle a¹ with the
spring a on which spindle the bobbin is mounted, the cover a³ and in connection
with this latter, the thread tightener a', the arrangement and method of operation
of which will be readily understood from the Drawing. The carrier B consists of
a disc b¹ provided with the pins b, b, and which is in firm connection with the
toothed wheel d.
In Figs. 2, 3 and 4 is shewn how the sewing operation is performed, this
being brought about as follows:-
The needle descends and again ascends, by this movement leaving behind it the
upper thread in the form of a loop. In this loop, one of the engaging hooks 1, 1, of
the bobbin holder A becomes engaged and carries the same along with it, so that
(Fig. 2) the bottom thread comes to lie within the loop of the upper thread.
Whilst the bobbin holder completes half a revolution, the needle forms another
loop of the upper thread, in which the succeeding engaging hook engages. By
reason of this engagement, the loop already formed will, -on the further turning of
the bobbin holder,-be drawn close.
Having now particularly described and ascertained the nature of the said
Invention (as communicated to me) and in what manner the same is to be
performed, I declare that what I claim is,
1. The oblique arrangement of the bobbin holder with reference to the carrier,
so that the projecting pins in the same serving to engage into and carry along
the bobbin holder, only engage at the lower part thereof, and become
separated therefrom upon continuing to revolve, substantially as hereinbefore
described and represented in the accompanying Drawing.
2. In the bobbin holder, the arrangement of two engaging hooks opposite one
another, which engage into and carry along the loop formed of the upper
thread by the needle, for the purpose of completing two stitches at one
revolution, substantially as herein before described and represented in the
accompanying Drawing.