Improvements in Sewing Machines.
Year: 1890

page_text: Date of Application, 18th Nov., 1890-Accepted, 20th Dec., 1890
CODILE DECIFICATION.
[Communicated from abroad by THE SINGER MANUFACTURING COMPANY, of New York,
in the United States of America, Sewing Machine Manufacturers.]
Improvements in Sewing Machines.
I, LEWIS HENRY SMITH, of Kilbowie, Dumbartonshire, Sewing Machine Expert,
do hereby declare the nature of this invention and in what manner the same is to be
performed, as communicated to me to be particularly described and ascertained in
and by the following statement :-
-
This invention which relates to sewing machines, has for its objects (1) the
production of a novel mechanism for actuating the feeding device or bar, the
same being moved positively from the main shaft in the overhanging arm of
the machine, the construction of the mechanism enabling the length of the feed
to be readily adjusted. (2) To make provision for raising the needle clear
of the work-plate when removing or placing the fabric in position for stitching: Tho
feed bar to be reciprocated is shown as jointed at an end to an arm of a rocking shaft,
parallel to the main rotating shaft, the latter being provided with a cam or eccentric
which is embraced by two arms of a forked lover provided with a guiding slot or way
with which co-operates a block pivotted upon a link the lower end of which is jointed
directly to an arm of ibe same rocking shaft to which is jointed the said feed har to
be reciprocated, the said link having combined with it means, as hereinafter described
and claimed, whereby the position of the block attached to it may be moved toward or
from the fulcrum of the said forked lever and in or with relation to the said slot
or way; the greater the distance of the said block from the said fulcrum, the greater
the longitudinal movement, of the said link and the greater the length of the stroke
or reciprocation of the feed bar actuated by the said rocking shaft. The needle-bar is
formed in two or more parts jointed together so that its lower end may be swung out
of the normal vertical line to an approximately horizontal position away from the
work-plate. In the accompanying drawings:-Figure 1, in side elevation represents
a sufficient portion of a sewing machine to enable my invention to be understood:
Figure 2. a right hand elevation thereof to the left of the dotted lino x. Figure 1.
the link and forked lever being shown as dotted in behind the frame-work, and
Figures 3, 4, and 5, details to be referred to.
The bed plate A, up-right arm A¹ and overhanging arm A constitute part of the
frame-work.
The feed-bar a to be reciprocated has at one end, as herein shown, a toothed
block a', which enters a slot or opening in the plate A.
The rear end of this feed bar is jointed to one or more arms a² of a rocking shaft a³
sustained by pointed screws, a* a'.
This rocking shaft has an arm a to which is jointed the lower end of a link b
provided at its upper end with a swivel block or slide which co-operates with a slot
or guide-way of a forked or bifurcated lever having its fulcrum at *, the said
slot or guide-way in the said lever being made across the same in a diagonal
direction, the fulcrum of the said lever being near one end of the said slot.
The forked end of the lever 6s embraces a cam or eccentric 6 on the rotating
shaft d having proper bearings in the frame-work and rotated in any usual manuer.
The link is connected to the screw e by a coupling link e¹.
The threads of the screw e preferably left-handed, are surrounded and engaged by
a thumb-nute threaded externally preferably right handed and of coarser pitch than
the threads of the screw e.
The nut is screwed into the frame-work and when turned in one direction or the
other moves longitudinally with it the screw e at a speed equal to the difference in
the pitch of the threads of the said screws. The turning of the nut causes the link b

page_text: to be moved so as to place the swivel block or stub closer to or further from the
fuleram of the lever in the slot or guide way so thit as the said lever is rocked
by the cain or eccentric the link b is moved in the direction of its length for a greater
or less distance the farther the block from the fulcrum the greater the stroke of
the link and the greater the extent to which the rocking shaft a³ is turned and the
greater the stroke or reciprocation of the feed bar a und vice-versa.
The needle n instead of being fixed in the needle bar in the usual way is secured as
shown in Figures 1 and 5, in a socket piece n' at the lower end of a bent arm n²
jointed at its upper end to a projecting arm n³ on the needle bar a said socket piece
forming, when the needle is in the working position, a continuation of the length of
the needle bar and being held fast, in such position by a spring pressed pin or
piston in the lower end of the needle bar proper entering a recess in the socket
piece. On the bent arm n² carrying the socket piece and needle is centred a small
hand lover whose inner end pl engages a projecting finger p on the spring-pressed
pin or piston n and by means of which said pin or piston may be raised to lift it out
of the socket piece and thereby free the latter so that the bent arm and
needle a, may be swung on its joint from the vertical to an approximately horizontal
position away from the work-plate.
Having now particularly described and ascertained the nature of the said invon-
Lion and in what manner the same is to be performed, as communicated to me
I declare that what 1 claim is :-
1. In a sewing machine, the combination with the rotating shaft d provided with a
cam or eccentric, of the forked lover 6 embracing the said cam or eccentric and
having the slot, the said lever being pivoted near one end of the said slot, the feed
har a
"the rock-shaft a³ with which the said feed bar is connected, the link b jointed
to an arm of the said shaft a³, the block or stud carried by the said link and entering the
said slot the link e jointed to the said link b, the screw e provided with ears to which
the said link eis pivoted, and the adjusting nut tapped in the framework and
threaded internally to receive the shank of the said scrow e¹, the external threads of
the said nuts being of a coarser pitch, than tho threads of the said screw, wheroby a
differential adjustment is secured, substantially as set forth.
2. In a sewing machine a needle bar composed of two separable parts jointed and
secured together substantially as described.
3. In a sewing machine the combination of the needle bar, n², the needle carrying
socket piece n¹ and bent arm n³, spring pressed pin nº, engaging the socket piece and
a lever as p for freeing the pin from the socket piece substantially as described.
Dated this Seventeenth day of November 1890.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.