Improvements in Sewing Machines.
Year: 1896

page_text: Improvements in Sewing Machines.
I, MARK THOMAS DENNE, of Rushden, in the County of Northampton,
Engineer, do hereby declare the nature of this invention to he as follows:-
My invention relates to improvements in sewing machines of the kind forming
the subject, of Letters Patent granted to me Nos. 10025 and 10026 of 1892.
According to my present invention I employ a feed-motion constructed as
follows. A lever is pivoted to the frame of the machine and has a motion
imparted to it by a cam upon the driving shaft. In this lever is formed a groove
in which is a sliding block carrying a pin engaging with a similar block in a slot
in a second lever pivoted also on the frame at a point opposite to the pivot of the
first and arranged with respect to the first so that the before mentioned groove
lies parallel with the slot when the first lever is in a position at right angles to the
cam-shaft or at its dead point.
The before mentioned sliding block which carries the pin engaging with the
second block aforesaid also has a projection which comes in contact with suitably
arranged stop-pieces which can be adjusted so as to allow any alteration in the
length of stitch by moving the said blocks nearer to or further from the fulcrum
of the first mentioned lever and thus transmitting a varying amount of motion to
the second lever with a constant motion of the first, and through suitable connections
to the feed-slide carrying the channel-guide formed to move in the channel in the
sole of the shoe and also actuating the awl feed, the two acting together.
Any required alteration in the length of the stitch can be obtained while the
machine is in motion by moving the aforesaid block against either of the stops
where it is caused to remain by a friction device consisting of a spring pressing on
the first mentioned block.
The thread book is carried on one end of a bell cranked lever which is pivoted
on a block capable of moving round a centre at right angles to the lever pivot and
thus forming a universal joint. The opposite end of this lever carries two cam
rollers one of which is spherical and is adapted to move in a suitable race cut in
the face of a cam upon the driving shaft and the other to roll upon the surface of
the said cam, which is so shaped as to produce the motion for bringing the thread
hook into line with and immediately before the thread, the other or spherical
cam race giving to the lever and hook the backward motion required to pull the
thread down the inclined edge and across the barb of the needle.
The lever and roller are kept in contact with the face of the cam by a spring.
A semi-rotatory motion is given to the needle and awl upou their common axis by
means of two segments which are moved by rollers engaging with cams. The
shuttle is driven by a worm and pinion.
The table or support for the work is carried by an arm pivoted on the frame of
the machine and provided with teeth which engage with those cut upon a pinion
revolving with its shaft in a suitable bearing, which shaft carries upon its end
farthest from the pinion a disc provided at its edge with pointed teeth suitable for
the wedge-shaped detent piece which engages with them. This detent piece is
carried at one end of a bell cranked lever pivoted to the frame of the machine and
provided at its opposite end with a roller which engages with a cam in such a

page_text: manner as to press the detent piece into the before mentioned teeth in the disc for
nearly the whole of a revolution of the shaft and to allow it to be retracted by a
spring at one point to release the before mentioned arm and table to allow of its
adjusting itself to the varying thicknesses of work and to enable the work to be
placed in position. The table and arm are kept in contact with the work by means
of a spring.
The thread is given off as required for each stitch by means of a grooved wheel
which bites upon the thread and is provided with ratchet teeth. The pawl engaging
with these teeth is carried in an extension of a shaft which is pivoted in a hole
through the centre of the hub of the said grooved wheel and is provided at its farthest
end with a lever adapted to engage with a stud or projection upon one of the cams
which gives motion to it, thereby actuating the shaft and pawl and so turning the
ratchet and grooved wheels before mentioned and giving off the thread.
The said lever and shaft are moved back after the stud upon the cam has
actuated them by a spring against a stop which is adjustable and so determines the
amount of thread given off. As the aforesaid lever comes more or less into the
path of the before mentioned stud so the length of thread is varied.
A brake strap
is adapted to the hub of the aforesaid grooved wheel to prevent a retrograde
movement when the pawl and its carrier and shaft are returned by the spring.
The take-up is a simple lever provided with a roller engaging with a cam and
carrying at its free end a thread roller.
The auxiliary spring take-up consists of a disc which is journalled in an
extension of the thread blade block and carries upon its face two pivots for thread
rollers and which is revolved by means of a spring.
The thread is carried by these rollers in such a manner that the disc is caused to
revolve upon its axis when any pull is exerted on the thread in opposition to the
spring, thus keeping an even tension upon the thread.
The needle guard is journalled upon an extension of the boss of the needle
carrier and embraces the needle. It is controlled by a stop-pin.
The needle and awl carriers and thread blade are all carried by an arm having
a projection fitting the needle carrier and supporting a sleeve upon which the awl
carrier receives the semi-rotary motion which is imparted to it by the cam and
segment and also the sliding motion given it by the feed motion through a plate
carried by the feed-slide engaging with a circular recess formed in it.
The before mentioned projection is free at the end upon which the awl carrier
moves so that it is possible to remove the awl carried by lifting the before
mentioned plate only.
The thread blade is secured to a block which also carries the auxiliary take-up,
and consists of a plate formed to the required shape to allow of the thread being
pulled down its edge into the barb of the needle. Upon this plate is secured a
second plate carrying a projection pierced with an eye.
The shuttle hook is revolved in a race above the needle and in a plane at right
angles with it, in such a position as to enable it to take the thread directly from
just below the point of the needle and to throw the loop over itself, the needle
dipping behind the hook when passed to drop the loop.
In the shuttle hook and its bearing ring is formed a circular recess from the
bottom of which projects a pin upon which revolve the cop holder which is a box,
adapted to carry the cop of thread and provided with a hinged door, and a tension
spring which is adjusted by a screw.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.

page_text: I, MARK THOMAS. DENNE, of Rushden, in the County of Northampton,
Engineer, do hereby declare the nature of this invention and in what manner the
same is to he performed, to be particularly described and ascertained in and by
the following statement:-
My invention relates to improvements in sewing machines of the kind forming
the subject of former Letters Patent granted to me Nos. 10025-and-10026 of-1892-
and comprises improvements as hereinafter described.
In the accompanying drawings,
Figure 1 is a front elevation of a sewing machine embodying my improvements:
Figure 2 is a side elevation of the same; and,
Figure 3 is a plan:
Figures 4 to 20 are views hereinafter described illustrating the arrangements of
the different parts of the mechanism.
Similar letters of reference indicate corresponding parts in the several figures.
a is the frame of the machine and 6 is the driving shaft supported in bearings in
the said frame and carrying the cams through the medium of which movements are
imparted to the various parts as hereinafter described, c is the awl carrier and dis
the needle carrier both of which oscillate or rotate upon a stud d carried by a
bracket d Figures 1, 2 and 3 fixed to the frame of the machine.
The lateral movement of the awl carrier to produce the feeding of the work is
effected by the following means, from a cam c on the shaft having in it a
groove c, as will be readily understood by reference to Figures 4 and 5 which are
respectively a side elevation and a plan illustrating the arrangement of this feed
mechanism. To the frame a a lever 3 is pivoted at one end c' whilst the other end
carries a roller c which runs in the groove c², in connection with this lever is
arranged a second lever c pivoted at one end e to the frame a and carrying at the
other end a pin carrying a block fitting into a slot in a projection 10 formed
upon the boss c¹¹ of a lever c, the said lever c¹, being mounted upon a pin con
the frame of the machine in such a manner that it can move laterally and also
oscillate upon the said pin. The free end of the said lever has the channel guide c¹4
upon it and the said lever is also provided with a blade cl which projects down
and into a slot or groove in the awl carrier c in such a manner that whilst it in no
way interferes with the oscillations of the said awl carrier it transmits lateral
movement to the same.
The levers, are slotted to receive a pin ee through the medium of which the
movement of the lever c³ which is positively operated by the cam c is transmitted
to the lever c to move the lever c2 Jaterally. It will be obvious that the nearer
the pin is placed to the pivot c of the lever c the greater will be the amount
of movement imparted to the free end of the said lever ce from the lever c³ and
vice versa.
A knob c on the pin e permits of adjusting the said pin to regulate
the feed. The opposite end of the lever c to that which carries the channel guide
carries a roller c running upon a cam chaving in it a depression 20 which at
each revolution of the cam lifts the channel guide so as to release the work during
the backward movement, a spiral spring, not shewn in the drawing, serving to
depress the said roller c18 into the said groove.
The arrangement of feed mechanism hereinbefore described permits of altering
the length of the stitch while the machine is in motion it being simply necessary
to move the knob c7 in one direction or the other as desired in order to increase or
diminish the lateral movement transmitted to the lever c¹².
Another part of my invention relates to improvements in the thread hook or

page_text: puller for drawing the thread into the barb of the needle and these improvements
are illustrated in Figures 6 and 7 of the drawings which are respectively a side
elevation and a plan of the said thread puller with its operating cam. e is the hook
or puller proper which is carried at one end of a bell-cranked lever e' pivoted upon
a pin or stud e fixed to a pin e rotating in a socket in the frame a so that the said
lever is capable of moving over a small distance in a horizontal plane upon the
pin and also in a vertical plane upon the pin the two pins thus constituting a
universal joint. The other end of the lever el which is operated by the cam disc e'
carries two rollers e, e the former of which is a ball running in a suitably shaped
groove e' in the said cam disc and serves to impart a vertical movement to the
thread puller, whilst the other is a plain roller running against the face of the said
cam and serving to impart a horizontal movement to the said puller. The object
of employing a ball e is that when the pin upon which the said ball runs takes an
inclined position relatively with the axis of the cam, as shewn in Figure 7, no
undue friction shall be set up between the said roller and the groove in which it
runs. The roller e is kept in contact with the face of the cam disc cl by a spring
arranged in conjunction with the lever el but not shewn in the drawings.
Another part of my invention relates to the operation of the awl carrier e and
the needle carrier d. Figures 8 and 9 shew in elevation and plan respectively
the awl carrier e with its operating lever fand operating cam, which latter is a
groove formed in one face of the cam c hereinbefore described in which groove
the roller of the lever fruns, and Figures 10 and 11 are similar views of the needle
carrier d with the lever g and cam g for operating the same.
It will be noticed that in both cases the lever has a segment of teeth upon it
engaging with corresponding teeth formed on the carrier.
9, Figure 10, is a needle guard carried loosely upon the boss of the needle
carrier and actuated as described in the Specification No. 10025 of 1892.
Another part of my invention which relates to the shuttle is illustrated in
Figures 12 and 13 which are respectively an elevation and a longitudinal section
drawn to a larger scale than Figures 1 and 2 of the drawings.
i is the rotary shuttle which is made hollow to receive a thread box and has
the hook formed upon it, the said shuttle being adapted to rotate in the raceway
formed in a plate 2 secured to the frame and being rotated by a driver engaging
with the hook it. The said driver is fixed to a disc at one end of a shait to
the other end of which is secured a worm or spiral pinion (Figure 3) with
which helical teeth on the periphery of the cam cengage. This gearing is
so arranged that the shuttle makes two revolutions to each revolution of the cam
shaft b.
The thread box is carried in the shuttle upon a central bearing pin
projecting from the back of the shuttle but is prevented from revolving with the
shuttle by reason of the fact that the thread which passes out of the thread box
through an opening in the centre thereof, passes under a spring and eye
directly to the work. The pressure of the spring upon the thread is adjusted by
a screw, fixed on the lid 13 of the said box, which lid is hinged to the box at
and provided with a spring snap
Another part of my invention relates to the welt guide or work support and to
the means for locking and releasing the same. These improvements are shewn in
Figures 14 and 15 which are respectively front and side elevations of the work
support and its connected mechanism.
is the work support or table proper which co-operates with the channel guide
in a manner described in the specifications before referred to. This work support
is carried by an arm j pivoted to the frame of the machine the said arm being
provided at its lower end with a segment of gear teeth which engage with a
pinion formed upon or attached to a shaft carrying at the end most remote
from the pinion a dise ; having pointed teeth on a portion of its periphery. is a
lever mounted in the frame of the machine and carrying at one end a roller which
runs upon the cam g¹ hereinbefore described whilst the other end carries a detent j

page_text: adapted to engage with one or the other of the pointed teeth on the disc . In
connection with the lever j a spring (not shewn) is arranged the normal tendency
of which is to draw the detent out of engagement with the teeth of the disc
whilst the normal tendency of the cam g is to retain the detent in engagement
with the teeth, the said cam g' being cut away at one point in the periphery to
permit of the detent moving out of engagement with the teeth under the action of
the spring.
The disc encloses a coiled spring the effect of which is to rotate it in such a
direction as to keep the work support in close contact with the work; a handle
is provided for use in placing the work in the machine.
Another part of my invention relates to improved means for giving off the
required amount of thread for each stitch my improvements for this purpose being
illustrated in Figures 16, 17 and 18 which are respectively, a front elevation, a
side elevation and a plan illustrating this part of my invention.
is a grooved wheel loosely mounted on a stud carried in the bracket fixed.
to the frame of the machine and over which the thread passes from the spool to
the work, this wheel k has fixed upon it a ratchet wheel with which a spring
pawl carried in au arm k formed on one end of the stud k° engages. Upon the
other end of the stud is an arm & against which a projection upon one face of
the cam is designed to impinge as the said cam rotates in such a manner as to
oscillate the said arm and thereby impart motion to the ratchet wheel and to the
pulley k. The said arm or lever and the shaft or stud ko are moved back against
a stop (not shewn in the drawings) after the projection upon the cam chas
actuated them, by means of a spring. This stop is made adjustable so as to
determine the extent of the backward movement of the said arm and consequently
also the amount of rotation imparted to the ratchet wheel and the amount of
thread given off.
A brake strap k, one end of which is fixed to a part of the bracket k¹ whilst the
other end is fixed to the hub of a lever k³, bears upon a surface k on one side of
the drum. In order to prevent the backward movement of the arm k from
imparting motion to the ratchet wheel the pressure of this band may be adjusted
by means of a set screw 10 passing through the lever 8 and bearing with its inner
end against a spring &" which permits of the pressure of the said band upon the
surface being slightly yielding.
Instead of this adjustable brake I may employ a simple locking device applied to
the lever of the work supporting mechanism, the motion of which lever is
utilized for causing a detent or stop to engage with the ratchet wheel ". This
stop acts to prevent the pulling off of the thread during the downward pull of the
take-up and is released during the upward struke to allow of the thread necessary
for completing the stitch being drawn from the ball or cop of thread.
According to another part of my invention the take-up is in the form of a lever!
(Figures 1, 2 and 3) the said lever being actuated by a cam and carrying at its
free end a roller over which the thread passes.
Instead of this arrangement of take up I sometimes use a compound system of
levers to enable me to obtain an adjustable stroke, one of the levers of the system
being slotted and connected to the other lever by a link.
Another part of my invention relates to an auxiliary spring take up the
construction of which is illustrated in Figures 19 and 20 which are respectively
front elevation and a side elevation of the said take up drawn to an enlarged scale."
In these figures m is a block which is fixed to the bracket d' (Figures 1, 2 and 3)
of the machine and which carries the thread blade mo, made of the required shape to
allow of the thread being pulled down its edge into the barb of the needle, and
second blade m' having an eye m³ formed in it for the passage of the thread.
m is the auxiliary take up proper which consists of a disc mounted upon a bearing
pin and having arranged within it a spring m. This disc carries two rollers mo, m
around which the thread is carried the said disc is retained by the spring against a
suitable stop in the position shewn in Figure 20 and any pull on the thread tenda

page_text: to turn the disc upon its axis in a direction against the pressure of the spring thus
keeping an even tension upon the thread.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be perforined, I declare that what I
claim is :-
1. In a sewing machine of the kind described the construction and arrangement
of the feed motion, substantially as set forth.
2. The combination with the feed motion referred to in the previous claim of
means for raising and lowering the channel guide, substantially as described with
reference to Figures 4 and 5.
3. In a sewing machine of the kind described, a thread hook or puller for
drawing the thread into the barb of the needle, and means for actuating the same
substantially as described by reference to Figures 6 and 7 of the accompanying
drawings.
4. In a sewing machine of the kind described a rotary shuttle baving the
improved construction and arrangement of thread box, substantially as described
with reference to Figures 12 and 13.
5. In a sewing machine of the kind described, the combination with the work
support of means for locking the same, substantially as described by reference to
Figures 14 and 15 of the accompanying drawings.
6. In a sewing machine of the kind described, the means for controlling the let
off of the thread, substantially as described by reference to 'Figures 16, 17 and 18
of the accompanying drawings.
7. The improved sewing machine consisting of the parts constructed and combined
substantially in the manner herein before described and illustrated in the accom-
panying drawings and operating as, and for the purposes, set forth.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.