IMPROVEMENTS IN SEWING MACHINES
Year: 1879

page_text: LETTERS PATENT to John Keats, of Wood Green, in the County of Middlesex,
Engineer, for the Invention of "IMPROVEMENTS IN SEWING MACHINES."
Sealed the 29th April 1879, and dated the 1st January 1879.
PROVISIONAL SPECIFICATION left by the said John Keats at the Office of
the Commissioners of Patents on the 1st January 1879.
JOHN KEATS, of Wood Green, in the County of Middlesex, Engineer. "IMPROVE-
MENTS IN SEWING MACHINES.”
The object of this Invention is to produce a top feed and presser for sewing
machines that will be self adjusting to suit varying thicknesses of work, such as
constantly occur in boot sewing, and which will, without pressing severely upon the
work, offer a firm resistance to the pull of the needle thread.
To this end I use for the operations of pressing and feeding one and the same
instrument, which consists of a bar with a tapering end, terminating in a chisel
edge for leather work, or a serrated or roughened end for other kinds of work.
This presser and feed bar I mount in a movable guide box, which is free to slide
in or with its supports.
This guide box is slotted longitudinally on one side to allow of a pin attached to
the presser bar projecting through the guide box to receive the end of a coiled
spring, which connects it elastically with the guide box, and thus allows it to move
therewith or to receive an independent motion.
Pivotted to the guide box is a gripping jaw, which is capable of moving inwards
through a slot in the guide box, and pressing against the presser and feed bar, so as
to lock it and its guide box together.
This inward motion of the gripping jaw is caused by the pressure of the bowle
of a rock lever at the back of the jaw, and by means of an incline on the back of
the jaw the bowle is caused to trip the jaw and disengage it from the presser bar.
The guide box, besides having a vertical motion for lifting the presser off the work,
has a lateral tipping motion to give to the bar the requisite forward feed motion.
These two movements of the guide box are obtained from a rock lever mounted on
a universal joint, and actuated by a compound cam, the connection of the lever
with the guide box being through a ball and socket joint.
The amount of vertical motion of the guide box will be determined by the extreme
limit of the varying thicknesses of the work, and the presser bar being always
locked with the guide box at the time of its vertical movement will rise with it,
Price 8d71

page_text: clearing any extra thickness of work which the last feed movement may have
brought towards the needle. On the next descent of the guide box, the presser bar
being at that time disengaged from the gripping jaw, the descent of the presser bar
will be arrested by the work, and its position with regard to the guide box will be
consequently shifted. At the next rise of the guide box, the presser bar being now
drawn back by a coiled spring, will be carried up as before the full distance of the
rise of the guide box, and when the extra thickness of work has passed from under
the needle, the presser bar, in addition to the downward movement of the guide
box, will receive a downward impulse from the coupling spring before mentioned,
which will press it down upon the work. The presser bar will however receive from
this spring a comparatively slight pressure, and to enable it to resist the pull of the
needle when drawing up the loop to tighten the last formed stitch, it is assisted by
the gripping jaw before mentioned, which, while the bar is either pressing or feeding,
binds it tightly to the guide box, and thus enables it to resist any strain that may
be put upon it. To provide for the lifting of the presser bar, and holding it up
clear of the work, a pin projects from this bar through a slot in the guide box, and
overlies the end of a rock lever, which is capable of being actuated by a treadle.
By the depression of the treadle the gripping jaw is first released from the presser
bar, and the end of the lever underlying the pin just mentioned rising, will lift
the presser bar in the guide box, the coupling spring yielding to permit of its
rise.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Keats in the Great Seal Patent Office on the 1st July 1879.
JOHN KEATS, of Wood Green, in the County of Middlesex, Engineer. << IMPROVE-
MENTS IN SEWING MACHINES."
The object of this Invention is to provide sewing machines with a top feed and
presser, which will be self adjusting to suit varying thicknesses of work, such as
constantly occur in boot sewing, and will, without pressing severely upon the work,
offer a firm resistance to the upward pull of the needle thread.
To this end I use for the operations of pressing and feeding one and the same
instrument, which consists of a bar with a tapering end, terminating with a
chisel edge for leather work, or a serrated or roughened end for other kinds of
work.
Referring to the accompanying Drawings, Fig. 1, Sheet I., is a side elevation of
so much of a sewing machine, modified according to my Invention, as will serve to
explain the nature of the improved top feed; Fig. 2, Sheet II., is a front elevation ;
and Fig. 3, Sheet III., is a plan view of the same; and Fig. 4 is a sectional plan on
the line 1, 2, of Fig. 1.
In these Figures, A is the framing of the machine standing up from and over-
hanging the bed plate. Bolted to the upper end and vertical face of this framing is

page_text: a hollow head consisting of two parts B, B¹, for receiving the vertical needle or hook
bar C, and the pressing and feed bar D.
This presser and feed bar I mount in a moveable guide box D', which is free to
slide in the hollow head; its upper end passes over a pivotted guide 6 mounted in
the head.
This guide box is supported by being connected through a ball and socket joint
(see the sectional plan view, Fig. 4), with a rock lever D³, which rock lever has its
fulcrum at d, and is actuated by means of cams D3, D4, mounted on the cam shaft E.
The fulcrum pin of this rock lever is carried in forked bearings formed on the head
of a vertical pin d, as shewn in the detached view, Fig. 5, Sheet I., which has its
bearings in a bracket piece attached to the main framing.
This mode of mounting the lever permits of its receiving a vertical rocking
motion from the cam D³, and thus of raising and depressing the guide box D', and
also of receiving a lateral rocking motion from the face cam D', in order to give a
forward and backward motion to the guide box, for the purpose to be presently
explained.
This guide box D₁ is slotted longitudinally in front to allow of the crosshead of
the presser bar D projecting through the guide box. The front projection of the
crosshead carries a saddle piece having horns extending outward on both sides to
receive the ends of coiled springs d³, the lower ends of which are connected to horns
projecting from a vertical standard B2, forming part of the hollow head B¹. This
standard extends upward, and forms a rest for the crosshead of the presser bar D
when that bar is in its lowest position, as shewn. in the front view, Fig. 2 and Fig. 6,
the latter being a detached view of the guide box D¹ and presser bar D.
Pivotted to the guide box D¹, and within the side opening thereof, is a gripper F
see the vertical section of the guide box, Fig. 7. This gripper is intended to move
inwards in the longitudinal side opening of the guide box, and press against the
presser and feed bar, so as to lock it and its guide box together.
The means for operating this gripper is as follows:-At the back of the gripper,
pivotted between cheeks forming part of the guide box, is a small cam or cam
shaped lever F*, with the snail part of the cam resting against the back of the
pendant gripper F, which thus lies between the cam and the back of the presser
bar. The cam-shaped lever extends backward from the guide box D¹, and upon this
extension of the lever bears a pressure screw carried by a rock lever F¹, which has
its fulcrum at f. The fore part of this lever carries horns extending outwards on
both sides, to which are connected coil springs F2, the lower ends of which are
attached to studs projecting from the sides of the rock lever D³.
By the pull of these springs the pressure screw of the lever F' is held down upon
the arm of the cam shaped lever F*, which transmits its pressure to the pendant
gripper F, and retains it in action. In rear of its fulcrum f, this lever carries a
bowl, which is operated upon by a cam F³ formed by a projection on the lower end
of the needle bar cam C on the cam shaft E, and the lever F' is thus caused to
relieve the gripper of pressure, in order that the pressing and feeding bar may move
independently of the guide box.
The vertical motion given to the guide box by the rock lever D³ is for the purpose
of lifting the presser off the work, at which time the presser bar is secured to the
guide box by the pressure of the gripper, and the lateral tipping motion, which the
guide box also receives from the rock lever D², serves to give to the bar the requisite
forward feed motion. The return motion of this bar with its guide box is derived
from the spring D³ (see Fig. 3), which connects the tail of the lever D² with a fixed
point on the framing.
The amount of vertical motion of the guide box will be determined by the
extreme limit of the varying thicknesses of the work, and the presser and feed bar
being always locked with the guide box at the time of its vertical movement, will
rise with it, clearing any extra thickness of work which the last feed movement
may have brought towards the needle. On the next descent of the guide box, the
presser bar being through the proper timing of the cams during a portion of this

page_text: movement released from the grippen ; the descent of the presser bar will be
arrested by its striking on to the work, and its position with regard to the guide
box will be consequently shifted. At the next rise of the guide box the presser bar
will be carried up, as before, the full distance of the rise of the guide box, and when
the extra thickness of work has passed from under the needle, the presser bar, in
addition to the downward movement of the guide box, will receive a downward
impulse from the springs 3 (during the momentary relaxation of the action of the
cam shaped lever F* on the gripper F), which springs will press it down upon the
work. The presser bar will however receive from these springs a comparatively
slight pressure; and to enable it to resist the pull of the needle or look when
drawing up the loop to tighten the last formed stitch, it is assisted by the gripper F
before mentioned, which, while the bar is either pressing or feeding, binds that bar
tightly to the guide box, and thus enables it to resist any strain that may be put
upon it.
In Sheet IV. I have shewn the several cams above referred to as laid out in plano.
The relative positions of these cams is also determined by the vertical line which
is passed through the cams.
To provide for the lifting of the presser bar, and holding it up clear of the work,
the backward extension of the crosshead projects from the presser bar through the
slot in the guide box D¹, and overlies the end of the rock lever F¹, which is extended
for the purpose, as shewn best at Fig. 7. This lever I propose to actuato by a treadle,
the depression of which will bring the end of the rock lever F³ (see Sheet I.) down
on the rear end of the lever F, and tip the extended front end of the lover, and
through the cross head of the presser bar lift that bar, (which is now disengaged from
the gripper) clear of the work.
'
Having now set forth the nature of my Invention of "Improvements in Sewing
Machines," and explained the manner of carrying the same into effect, I wish it to be
understood that under the above in part recited Lotters Patent I claim,-
Firstly. Mounting the presser and feed bar in a vertically reciprocating guide, and
holding it firmly therein by a gripping or binding surface, in the manner and for
the purpose described.
Secondly. The arrangement of mechanism above described for locking the presser
and feed bar in position upon the work, and thereby enabling it to resist the upward
pull of the needle thread without unduly pressing up the work.
Thirdly. The arrangement of parts above described, whereby the presser bar
when locked to its guide, but will be free to receive the requisite motion for feeding
the work.
In witness whereof, I, the said John Keats, have hereunto set my hand and
seal, the Thirtieth day of May, in the year of our Lord One thousand