Improvements in or connected with Lock Stitch Sewing Machines.
Year: 1891

page_text: Date of Application, 11th Dec., 1891
Complete Specification Left, 12th Sept., 1892-Accepted, 5th Nov., 1892
PROVISIONAL SPECIFICATION.
Improvements in or connected with Lock Stitch Sewing Machines. .
We MARK CHARLES DENNE of 1 Tower Road, Eastbourne, Sussex, and
THOMAS JAMES DENNE of Hemel Hempstead, Herts, Engineers, do hereby declare
the nature of this invention to be as follows:-
In this machine a curved barbed needle is used and an awl, both penetrating
the material from below in combination with a rotary shuttle also below the work.
The motions of the awl, needle, feed, locking the presser foot, the looper, shuttle
etc. are obtained from cams and in the case of the shuttle, a toothed wheel revolving
on a shaft parallel to the direction of feed of the machine. The awl is attached to
an arm pivotted on a short shaft parallel with the before mentioned shaft, and
having a sliding motion in its bearings to effect the feed.
The awl is raised and depressed by means of a cam acting on the opposite end of
the carrying arm which is extended backwards and provided with a roller which
runs in cam groove.
The needle is attached to a similar arm which is not free to slide and which is
actuated by a cam through a link. It has a stroke several times longer than
the awl.
The feed is effected by the sliding of the before mentioned short shaft in its
bearings carrying with it the awl and carrying arm, by means of a lever engaging
with it and secured on a vertical shaft, which carries another slotted lever on its
upper end. This, by a link and second lever actuated by a barrel cam gives the
motion, which is varied by shifting the link further from or nearer to the centre
in the slot in the lever before mentioned.
The shuttle which consists of a ring with one side flat and the other bevilled off
so as to give a triangular section and which contains the spool within its thickness,
is placed below the awl carrying arm which operates above it and with the flat
side nearly in the plane of the needle's stroke and at right angles with the shaft.
It is held in a race which bears on the outside edge and which is cut away in
front to allow the booked point to act.
The needle passes across the flat face of the shuttle and the latter having a
projecting hook on its face whose point is in a line with the point of the needle, and
above it when the latter is at the lower end of its stroke engages at the proper
time with the thread. The point of the shuttle is so timed as to bring it to the
position for entering the loop when the needle has brought it down.
The looper which is a short lever carrying an eye on a rocking shaft parallel
with the before mentioned is vibrated by a bell crank lever actuated by an
edge cam.
The presser foot is locked by means of a lever extending back from the front of
machine where it is pivotted and kept in contact with an edge cam by a spring.
It has a vertical plunger attached to it near its fulcrum. The presser foot is
formed on the end of a similar plunger placed in front of the other and above the
work rest. These two shafts are connected by plates which encircle both, and
which on being tilted by the cam and lever jam and hold the presser foot.
The take up which is an arm carried by a short shaft above the cam shaft is
actuated by a cam through a link and roller.
The work is placed on a support slotted to allow the needle and awl passage and
the presser foot is brought down on it.
The awl which is placed out of the plane of the needle to the right then move

page_text: forward to the left, penetrates the material again moves the length of stitch
required, and recedes after bringing the puncture into the plane of the needle.
During the time the awl is passing up through the work the presser foot is locked
and when feeding is released. The hooked needle follows upwards through the
hole made by the awl and the thread from the reel is thrown into the barb by the
looper above, which vibrates from back to front. The needle then recedes taking
down the thread to the end of its stroke. The hook on the shuttle then passes the
point catching the thread at the side of the barb to the right leaving the other side
thread. The shuttle is so shaped as to allow of the thread when it has been taken
past the centre by the hooked point, to be pulled over it, and the thread from the
spool and be tightened into the work by the take up above, thus forming the stitch
and laying the shuttle thread underneath while the shuttle completes another
rotation during which the needle makes the stroke to bring down the thread.
Dated this 11th day of December 1891.
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said M. C. Denne and T. J. Denne.
COMPLETE SPECIFICATION.
Improvements in or connected with Lock Stitch Sewing Machines.
We, MARK CHARLES DENNE, of 1 Tower Road, Eastbourne, Sussex, and
THOMAS JAMES DENNE of Hemel Hempstead, Herts, Engineers, 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 :-
In this machine, a curved barbed needle is used and an awl, both penetrating the
material from below in combination with a rotary shuttle also below the work.
The motions of the awl, needle, feed, locking the presser foot, the looper, shuttle
etc. are obtained from cams and in the case of the shuttle, a toothed wheel revolving
on a shaft parallel to the direction of feed of the machine. The awl is attached
to an arm pivotted on a short shaft parallel with the before mentioned shaft, and
having a sliding motion in its bearings to effect the feed. The awl is raised and
depressed by means of a cam acting on the opposite end of the carrying arm which
is extended backwards and provided with a roller which runs in cam groove.
The needle is attached to a similar arm which is not free to slide and which is
actuated by a cam through a link. It has a stroke several times longer than
the awl.
The feed is effected by the sliding of the before mentioned short shaft in its
bearings carrying with it the awl and carying arm by means of a lever engaging
with it and secured on a vertical shaft, which carries another slotted lever on its
upper end. This, by a link and second lever actuated by a barrel cam gives the
motion, which is varied by shifting the link further from or nearer to the centre in
the slot in the lever before mentioned.
The shuttle which consists of a ring with one side flat and the other bevilled off
so as to give a triangular section, and which contains the spool within its thickness,
is placed below the awl carrying arm which operates above it and with the flat side
nearly in the plane of the needles stroke and at right angles with the shaft.
It is held in a race which bears on the outside edge, and which is cut away in
front to allow the hooked point to act.
The needle passes across the flat face of the shuttle and the latter having a
projecting hook on its face whose point is in a line with the point of the needle, and
above it when the latter is at the lower end of its stroke engages at the proper time
with the thread.
The point of the shuttle is so timed as to bring it to the position for entering the
loop when the needle has brought it down.

page_text: The looper which is a short lever carrying an eye or small hook is vibrated by
à bell crank lever or similar arrangement actuated by an edge cam.
The presser foot is locked by means of a lever extending back from the front of
machine where it is pivotted and kept in contact with an edge cam by a spring. It
has a vertical plunger attached to it near its fulcrum. The presser foot is formed
on the end of a similar plunger placed in front of the other and above the work rest.
These two shafts are connected by plates which encircle both, and which on being
tilted by the cam and lever jam and hold the presser foot.
The take up which is an arm carried by a short shaft above the cam shaft is
actuated by a cam through a link and roller.
Our invention will be understood by reference to the annexed drawings.
Figure 1 is a side elevation. Figure 2 a front elevation. Figure 3 a plan of the
machine. Figures 4, 5, 6 and 7 are detail views of the looper for throwing the
upper thread around the needle for engagement with its claw. Figure 8 a detached
view of the appliances by which the looper is operated, and Figures 9 and 10 side
view and section of the spool and spool carrier.
A is the bed. B, B, side cheeks. C main shaft. D presser foot. E awl.
F needle. G looper. H spool. I spool carrier. J, J, gear from main shaft to
spool carrier to drive same, two complete revolutions to each uprising of the needle.
K take up. L. pinion on looper G. M.quadrant for operating pinion L from
cam N. P stitch regulator. Qcam race for needle. R cam race for awl. S cam
race for take up. Taxle on which needle arm U and also the awl E works for
segmental up and down motion. V claw to hold ratchet wheel W from turning
while take up K draws in the thread.
The operation of the machine is as follows:-The work is placed on a support a
slotted to allow the needle F and awl E passage and the presser foot D is brought
down on it.
The awl E which is placed out of the plane of the needle F to the right then
moves forward to the left, penetrates the material again moves the length of stitch
required and recedes after bringing the puncture into the plane of the needle.
During the time, the awl E is passing up through the work the presser foot D is
locked and when feeding is released. The hooked needle F follows upwards
through the hole made by the awl E and the thread b from the reel is thrown into
the barb by the looper G above which vibrates from back to front. The needle F
then recedes taking down the thread b to the end of its stroke and to allow the
cotton to be drawn off the reel. The claw V is at this point disengaged from the
ratchet wheel by the cam A¹ lifting the rear end of the lever. The hook con
the shuttle I then passes the point catching the thread b at the side of the barb to
the right leaving the other side thread. The shuttle is so shaped as to allow of the
thread when it has been taken past the centre by the hooked point, to be pulled
over it and the thread from the spool and be tightened into the work by the take up
above, thus forming the stitch and laying the shuttle thread underneath while the
shuttle completes another rotation during which the needle makes the stroke to
bring down the thread. As before mentioned, the presser foot is firmly locked
during the penetration of the awl and the making of the stitch but is released during
the feed to allow of the free movement of the material.
For this purpose,
arrange a lever X fulcrummed at one end Y with a roller Z at the other for
operation by a cam A'; at a short distance from the fulcrum Y depends a rod B¹
in plane with the presser foot D to which it is connected by two loose plates C¹, C³,
retained in their relative positions upon the presser foot by the springs D¹ and upon
the depending rod B₁ by the stud projections E', so that when the lever X is lifted
by the cam A, said plates C₁, C³, are moved by the rod B₁ into a perfectly
horizontal position, and thus allow the presser foot to move freely up and down in
the holes of said plates C, C', whereas on the contrary, when the lever X is down,
the weight of said lever causes the sides of the holes in the plates C, C', to grip the
presser foot and prevent any movement. F¹ is a spring tending to keep the presser
foot down, and G' is a screw for regulating the tension of the springs D'.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The particular construction of the several parts and their combination in the
manner shown in the annexed drawings, and their use for the purposes specified.
2. In a sewing machine the particular arrangement and combination of the parts
for locking and releasing the presser foot, as set forth.
The 12th day of September 1892.
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said Mark Charles Denne, Thomas James Denne.