Improvements in Lock-stitch Sewing Machines.
Year: 1890

page_text: Date of Application, 28th Oct., 1890
Complete Specification Left, 27th July, 1891-Accepted, 19th Sept., 1891
PROVISIONAL SPECIFICATION.
Improvements in Lock-stitch Sewing Machines.
I, HENRY BIRCH, of 99 Kingsdown Parade, in the City and County of Bristol,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to lock-stitch sewing machines of the oscillating type and
lias special reference to machines used for executing what is known as "prickscam"
work in the manufacture of gloves.
One of the improvements comprised in this invention consists in special mechanism
for driving the shuttle. According to this invention the bar rack gearing with the
pinion of the spindle of the shuttle driver is connected to a balanced crank
secured on the main driving shaft, and, consequently, the rack as it reciprocates on
the pinion has also an oscillating motion. It is supported towards the free end in
a bracket through which the axis of the pinion passes. By virtue of this arrange-
ment a varying rate of speed is imparted to the shuttle, the arrangement being
such that the shuttle is at its slowest when the take-up begins to draw up the
loop, so that the latter is removed without liability of being pinched or jammed in
the shuttle race as the shuttle returns.
As a result of the above provision for tightening up the loops, the gap in the
shuttle race for the passage of the thread is of reduced width.
A second improvement consists in the method of attachment of the pinion above
mentioned to the spindle of the shuttle driver. Under this invention the pinion is
[mounted on a sleeve which slides over the spindle end and is clamped to the
spindle by screws. Accordingly, the shuttle is set in relation to the needle by
turning the driver spindle by hand to the necessary extent before the pinion is
clamped.
No index, such as marking the teeth of the rack, or of the pinion, to ensure
gearing of particular teeth, is required. The improvements above described are
applicable to machines both of the vertical and horizontal kinds.
A third improvement, applicable to horizontal machines only, relates to the wheel
feed. This, as made in accordance with this invention, is of a shape approximating
to that of a trumpet, the mouth being uppermost. It is supported in a pillar
springing upwards from the bed plate and contains in the mouth the shuttle race,
shuttle driver and shuttle. The spindle of the shuttle driver is passed through the
stem of the trumpet and is oscillated from below.
The shuttle
The rim of the mouth of the feed is milled or serrated, as is usual.
race is held by screws screwed into a bracket springing from the pillar, and the
shuttle cover is secured in the same or a similar way.
The throat plate, instead of being, as hitherto, separate from the shuttle cover,
is, under this invention, in one piece therewith.
To prevent the needle thread being drawn aside at the gap in the shuttle race
by the shuttle, a guide in the form of a staple is employed and depends from the
underside of the throat plate. The needle reciprocates through it.
A further improvement, forming part of this invention, and applicable to
horizontal machines only, relates to the means for regulating the number of
stitches to be made in a given length of material. Regulation in this respect is,
under this invention, effected by the employment of a lever engaging at one end,
which is forked, with a cam secured on the main driving shaft. At the other end,
which is slotted longitudinally, the lever is connected to the mechanism through
the medium of which the wheel feed is actuated.

page_text: The fulcrum of the lever is a clamping screw movable in a slot in the bed
plate.
When the screw is loosened, the lever is free to be moved longitudinally along
the underside of the bed plate. The number of stitches made in a given length of
material being sewn depends on the position of the fulcrum of the lever, the feed
being governed accordingly.
Another improvement, relating to horizontal machines, refers to the roll presser
for pressing the material being sewn against the wheel feed. Under this invention
the presser is free to slide on its hinge bar and is thereby capable of being readily
withdrawn from and replaced below the needle when a change of presser wheels is
required according to the class of work being executed.
A further improvement, relating to horizontal and vertical machines, refers to
the needle bar, and consists in an improved method of clamping therein the needle
or needles. According to this invention, the bar is bored near its periphery and is
split through its diameter, the split being across the bored aperture. After
inserting the needle it is clamped by a screw passed through one half of the bar
and screwed into the other half. The needle is brought close to the circumference
of the bar and works over the shuttle in close proximity thereto. When two
needles are employed, the second is secured in the same way as that above
described.
An improved method of carrying the needle bar, in both horizontal and vertical
machines, constitutes a part of this invention. According thereto the bar is
supported towards each end in a block contained in a channel provided in the frame
of the machine. These blocks are adjustable vertically so that the needle bar may
be raised or lowered according to the plane in which it is desired that it shall work.
After adjustment each block is held in position by a clamping screw screwed in the
frame of the machine and bearing against a stud which is a continuation of the
adjusting block.
In horizontal machines as hitherto constructed the needle works from the
operator between whom and the shuttle the roll presser intervenes. Now, in the
machine above described, the needle works towards the operator. The shuttle is
next the operator and the roll presser is beyond the shuttle which latter is, as
aforesaid, contained in the trumpet-shaped wheel feed instead of being embedded
in the head of the machine.
Dated this 27th day of October 1890.
NICHOLAS WATTS,
Bristol Bank Buildings, Bristol, Agent.
COMPLETE SPECIFICATION.
Improvements in Lock-stitch Sewing Machines.
I, HENRY BIRCH, of 99 Kingsdown Parade, in the City and County of Bristol,
Mechanical Engineer, 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 :-
23
This invention relates to lock-stitch sewing machines of the oscillating type and
has special reference to machines used for executing what is known as "prickseam
work in the manufacture of gloves.
One of the improvements comprised in this invention consists in special mechanism
for driving the shuttle. According to this invention the bar rack gearing with
the pinion of the spindle of the shuttle driver is connected to a balanced crank
secured on the main driving shaft, and, consequently, the rack as it reciprocates
on the pinion has also an oscillating motion. It is supported towards the free
end in a bracket through which the axis of the pinion passes. By virtue of
this arrangement a varying rate of speed is imparted to the shuttle, the arrangement
being such that the shuttle is at its slowest when the take-up begins to draw up

page_text: the loop, so that the latter is removed without liability of being pinched or jammed
in the shuttle race as the shuttle returns.
As a result of the above provision for tightening up the loops, the gap in the
shuttle race for the passage of the thread is of reduced width.
A second improvement consists in the method of attachment of the pinion, above
mentioned to the spindle of the shuttle driver. Under this invention the pinion is
mounted on a sleeve which slides over the spindle end and is clamped to the
spindle by screws. Accordingly, the shuttle is set in relation to the needle by
turning the driver spindle by hand to the necessary extent before the pinion .is
clamped.
No index, such as marking the teeth of the rack, or of the pinion, to ensure
gearing of particular teeth, is required. The improvements above described are
applicable to machines both of the vertical and horizontal kinds.
In the Provisional Specification left with my application for Letters Patent to
this my invention, it is set forth, as part thereof, that the wheel feed is trumpet-
shaped and that it contains in the trumpet-mouth the shuttle race, shuttle driver
and shuttle. I now find that these points are not novel and I accordingly desire to
have it understood that I do not include them as constituting a part of my invention.
The rim of the mouth of the feed is milled or serrated, as is usual. The shuttle
race is held by screws screwed into a bracket springing from the pillar, and the
shuttle cover is secured in the same or a similar way.
The throat plate, instead of being, as hitherto, separate from the shuttle cover,
is, under this invention, in one piece therewith. To prevent the needle thread being
drawn aside at the gap in the shuttle race by the shuttle, a guide in the form of
a staple is employed and depends from the underside of the throat,plate. The
needle reciprocates through it.
A further improvement, forming part of this invention, and applicable to
horizontal machines only, relates to the means for regulating the number of stitches
to be made in a given length of material. Regulation in this respect is,, under this
invention, effected by the employment of a lever engaging at one end, which is
forked, with a cam secured on the main driving shaft. At the other end, which is
slotted longitudinally, the lever is connected to the mechanism through the medium
of which the wheel feed is actuated.
The fulcrum of the lever is a clamping screw movable in a slot in the bed
plate.
When the screw is loosened, the lever is free to be moved longitudinally along
the underside of the bed plate. The number of stitches,made in a given length of
material being sewn depends on the position of the fulcrum of the lever, the feed
being governed accordingly.
A further improvement, relating to horizontal and vertical machines, refers to
the needle bar, and consists in an improved method of clamping therein the
needle or needles. According to this invention, the bar is bored near its
periphery and is split through its diameter, the split being across the bored
aperture. After inserting the needle it is clamped by a screw passed through
one half of the bar and screwed into the other half. The needle is brought close
to the circumference of the bar and works over the shuttle in close proximity
thereto. When two needles are employed the second is secured in the same way
as that above described.
An improved method of carrying the needle bar, in both horizontal and vertical
machines, constitutes a part of this invention. According thereto the bar is
supported towards each end in a block contained, in a channel provided in the
frame of the machine. These blocks are adjustable vertically in a horizontal machine
and horizontally in a vertical machine so that the needle bar may be moved
according to the plane in which it is desired to work it. After adjustment each block
is.held in position by a clamping screw screwed in the frame of the machine and
bearing against a stud which is a continuation of the adjusting block.

page_text: In horizontal machines, as hitherto constructed, the needle works from the
operator, between whom and the shuttle the roll presser intervenes. Now, in the
machine above described, the needle works towards the operator. The shuttle i
next the operator and the roll presser is beyond the shuttle which latter is, as
aforesaid, contained in the trumpet-shaped wheel feed instead of being embedded
in the head of the machine.
Referring to the accompanying sheets of illustrative drawings,
Fig. 1 represents a side elevation of my improved lock-stitch sewing machine of
the oscillating type for executing "prickseam" work in the manufacture of gloves.
Fig. 2 is a plan of the underside, the machine being turned bottom upwards.
Fig. 3 is a plan as seen from above. One of the improvements comprised in this
invention consists in special mechanism for driving the shuttle.
According to this invention, the bar rack a gearing with the pinion of the
spindle c of the shuttle driver is connected to a balanced crank e, such as is
common in sewing machines, secured by clamping screws e¹ to the main driving
shaft. Consequently, the bar rack a as it reciprocates and actuates the pinion b
has also an oscillating motion. The bar rack is supported at the opposite end
to the crank e in a divided bracket 9. The two parts into which the bracket g
is divided are secured in place by the screws g², Fig. 2, and the rack cover ³ is
secured to the bracket by screws g. The shuttle driver spindle c with which the
pinion is concentric is passed through the bracket g.
By virtue of this arrangement a varying rate of speed is imparted to the
shuttle.
The mechanism is so adjusted that the shuttle is at its slowest rate of rotation
when the take-up begins to draw up the loops of the needle thread and hence the
latter is removed without liability of being pinched in the shuttle race as the
shuttle returns. Accordingly, the gap in the shuttle race is enabled to be of reduced
width, a provision which entails less wear on the shuttle race. The gap in the
shuttle race is seen in the detached view Fig. 4 which represents a plan of the
wheel feed, the shuttle having been removed.
A second improvement forming part of this invention consists in the method of
attachment of the shuttle driver pinion to the spindle c.
According to this invention the pinion is mounted on a sleeve c¹ slid over the
lower end of the spindle c and clamped thereto by screws c². This method of
attachment enables the pinion to be readily set in relation to the needle motion
by turning the shuttle driver spindle c by hand to the necessary extent and then
clamping the sleeve c¹ to it. This arrangement dispenses with an index, such as
marking the teeth of the rack a or of the pinion b, to ensure gearing between
particular teeth.
The improvements above described are applicable to machines both of the vertical
and horizontal kinds.
The wheel feed is of a shape approximating to that of a trumpet. It is
supported in a pillar springing from the bed plate j. At Fig. 5 is represented a
detached plan of the wheel feed. The trumpet mouth, the rim of which is milled
as usual, contains the shuttle driver d, shuttle race and shuttle which is of any
ordinary description. I do not include, as my invention, the trumpet-shaped wheel
feed nor the provision that in it is contained the shuttle race, shuttle driver and
shuttle. The spindle c of the shuttle driver d is passed through the stem of the
trumpet and carries, as aforesaid, the pinion sleeve at the lower end. A side
elevation of the shuttle driver and part of the spindle is shewn at Fig. 6.
The shuttle race is secured by a screw to the bracket springing from the
pillar of the wheel feed. The shuttle cover m is secured above the race by the
screws ³. A lid surmounts the whole and is held by the binding screw h³ on
which when the screw is loosened the lid is free to turn as a pivot. A stop / is
provided to control the range of movement of the lid when closing the same. Fixed
on the top of the lid is a flat piece of steel e, for holding the threads prior to

page_text: commencing to sew and after completing a seam. The threads are inserted under
the short arms v¹.
Under this invention the throat-plate m' of the cover m is, instead of being
separate therefrom, made in one piece therewith, and to prevent the needle thread
being drawn aside at the gap in the shuttle race h', a guide n, in the form of a
staple-see Fig. 7 which represents a front view of the shuttle cover-is employed
and depends from the underside of the throat-plate into the gap. The needle
reciprocates through the staple.
A further improvement constituting part of this invention and applicable to
horizontal machines only, relates to the means for regulating the number of stitches
to be made in a given length of material. Regulation in this respect is, under this
invention, effected by the forked lever o the fork of which engages with a cam o'
carried on the main driving shaft of the machine. At the other end, which is
connected to the mechanisin by which the wheel feed is actuated, the lever o is
slotted, as seen at o³, Fig. 2. The mechanism by which the wheel feed is actuated
in the machine illustrated in the drawings consists of a cup formed in one piece
with or rigidly connected to the stem of the wheel feed, an arm pl cornected to
the lever o, a gripping device p², engaging with the rim of the cup, springs p
and p, a stop arm p³ and a stop, all arranged and operating as set forth in the
Specification of a former Patent granted to me-dated February 16th 1887,
No. 2449. Other arrangements of mechanism for reciprocating the wheel feed
may be employed, nothing being claimed in this respect as part of this invention,
other than the method of and means for regulating as follows.
The fulcrum of the lever o is a movable clamping screw capable of adjustment
to any desired point in the longitudinal slot provided in the bed-plate j. The
number of stitches made in a given length of material being sewn depends on the
position of the fulcrum in the slot and the consequent retardation or acceleration
of the wheel feed.
A further improvement comprised in this invention consists in the method of
securing the needle in the needle bar r¹. Under this invention the bar is divided,
as seen at Fig. 3 and in the detached view of. the needle and bar shown at Fig. 8.
The division extends across the bore in which the needle is inserted. After
insertion of the needle it is clamped by a screw 72 passed through one-half of the
bar and screwed into the other. The needle is brought nearer the periphery of the
bar and works over the shuttle in closer proximity thereto.
When two needles are employed they are both secured in the bar .in a manner
similar to that above described with reference to one needle only.
An improved method of carrying the needle bar, in both horizontal and
vertical machines, constitutes a part of this invention. According thereto the bar
is supported in blocks, Fig. 3, contained in recesses formed for their reception in
the frame of the machine.
The machine illustrated in the drawings, being a horizontal machine, the blocks
are adjustable vertically so that the needle bar may be raised or lowered according
to the plane in which it is desired that it shall work. In a vertical machine similar
blocks are adjustable horizontally for the like purpose. The blocks are clamped
after adjustment by the clamping screws s¹ screwed in the frame of the machine
and bearing against a stud or stem which is a prolongation of each block.
In horizontal machines, as hitherto constructed, the needle works from the
operator, the roll presser intervening between the operator and the shuttle.
Now in the machine constructed as above described and shown in the accom-
panying drawings, the needle works towards the operator. The shuttle is next the
operator and the roll presser t is beyond the shuttle which, as aforesaid, is contained
in the trumpet mouth of the wheel feed instead of being embedded, as hitherto, in
the head of the machine.
The roll presser t is free to slide transversely on its tilting bar u and is thereby
capable of being readily withdrawn from below the needle and replaced when a
change of presser wheels is required.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In an oscillating lock-stitch "prickseam" sewing machine, means for obtaining
a rocking motion of the bar rack a about the pinion by which the shuttle driver
is actuated, the said means consisting of a bracket such as g through which the
rack is passed, the bracket being free to rock about the axis of the spindle as a
centre, and thus to impart a varying rate of motion to the shuttle so as to prevent
the needle thread being jammed or pinched in the shuttle race as the shuttle
returns and, consequently, to admit of reduction of width in the gap of the shuttle
race, substantially as hereinbefore described.
:
2. In an oscillating lock-stitch "prickseam" sewing machine, mounting the
pinion on a sleeve such as c with clamping screws whereby the pinion is
capable of being set in relation to the needle motion prior to being clamped to the
spindle of the shuttle driver, substantially as herein before set forth.
3. The incorporation, as one piece, of the throat plate m' with the shuttle
cover m, substantially as described.
4. The provision in the shuttle cover of a guide such as the staple or eye n
for preventing the needle thread being drawn aside by the shuttle, as hereinbefore
set forth.
5. In an oscillating lock-stitch "prickscam" sewing machine, means for regulating
the number of stitches in a given length of material, said means consisting of a
forked lever such as o engaging with a cam such as o¹ on the driving shaft f and
capable of adjustment, by the movable fulcrum y in the slot in the bed plate j,
towards and from the mechanism by which the wheel feed is actuated, thus
governing the rate of speed of the feed in relation to the needle motion according
to the number of stitches to be made in a given length.
6. The method of securing the needle in the needle-bar, by dividing the bar
through the needle bore and clamping the needle in place by a screw passed above
it through one half of the bar and screwed into the other half, as hereinbefore
described and shown in the accompanying drawings.
7. Means for adjustment of the needle bar in its bed,' said means consisting of
blocks such as s adjustable in the machine frame, and screws such as s¹ for clamping
the blocks after adjustment, substantially as hereinbefore described and shown in
the accompanying drawings.
Dotal this 5th dev of TL 1901
NICHOLAS WATTS,
Bristol Bank Buildings, Bristol, Agent.