Improvements in Straw Plait Sewing Machines.
Year: 1895

page_text: Date of Application, 21st Aug., 1895
Complete Specification Left, 21st May, 1896-Accepted, 15th Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in Straw Plait Sewing Machines.
I EDMUND WISEMAN, of Cheapside, Luton, in the County of Bedford,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to straw plait sewing machines of the class or type
described in the Specification to my Patent No. 2485/78, wherein sewing
implements or needles attached to a carrier beneath the work plate are thrust
upwards through the work and co-operate with one or more looping devices
supported above and moveable with the presser foot.
The invention has more especial reference to the mechanism for effecting the
automatic variation of the needle stroke described in the Specification to Johnson's
Patent No. 5926/86 as applied to a straw plait sewing machine of the class or
type above mentioned, and termed "controller mechanism." The said controller
mechanism is self adjusting according to the thickness of work and constitutes a
connection between the presser foot or equivalent part of the machine and an
adjustable part of the needle operating mechanism, said adjustable part consisting
The
of a sliding block adjusted within a slot in the needle bar rock shaft arm.
adjustment of this block within its slot changes the needle stroke and is auto-
matically effected through the controller mechanism by the rise and fall of the
presser arm, consequently the position of the said block is determined by the
distance of the presser foot from the work plate due to the interposed thickness
of work. The object of my invention is to improve upon this controller mechanism
and to render the same more efficient and reliable..
The said controller mechanism was only operated positively by the descent of
the presser arm and reliance was placed upon a spring for operating it on the
rise of the same. Now it is found in practice that should the adjustment of the
automatic clamp which prevents the accidental shifting of the controller mechanism
become disarranged and the grip of the said clamp be decreased, the action of the
said spring will cause the said block to shift within its slot thereby interfering
with the proper working of the machine, the sudden impact of the pin on the
controller shaft lever arm against the top of the slot in the presser arm link
preventing the prompt settlement of the presser foot upon the work when the
machine is driven at speed. Also the needles are liable to be driven back by
the work and prevented from penetrating the same to the proper extent, so that the
needle eye fails to reach the proper height for the thread loop to be entered by
the looper. According to my invention I obviate these and other difficulties by
my peculiar arrangement of controller.mechanism which is operated positively
both by the rise and by the fall of the presser arm.
Further propose to simplify
and increase the efficiency of the automatic clamp.
According to my invention 1 connect the sliding block before mentioned, by a
link, with the lower end of a lever dependent from pivots at its upper end. This
lever call the controller lever. Fixed on the presser arm rock shaft is a
jointed lever of peculiar construction which is connected by means of a link
with a short arm on the upper end of the controller lever, the latter being thereby
positively operated both by the rise and by the fall of the presser arm.
This positive operation of the controller lever in both directions renders it.
necessary to provide means whereby the movement of its lower end due to the
slight rise and fall of the presser arm caused by the feed action may be diminished

page_text: or neutralised, otherwise the sliding block will be constantly shifting its position
during the working of the machine when not required. In order to effect this I
pivotally connect the upper end of the controller lever with a rocker mounted on
a short rock shaft carried in convenient bearings. This rock shaft, which I call
the controller lever rock shaft, is connected by an arm with a can on the main
shaft, termed the controller lever cam. When rocked by the latter the said rock
shaft so varies the position of the pivots which connect the rocker with the con-
troller lever as to reduce to a minimum and practically neutralise the movement of
the lower end of the latter caused by the action of the feed on the presser arm.
At the same time any movement of the presser arm in excess of the small play
caused by the feed action will move the lower end of the controller lever and effect
the adjustment of the sliding block to the position requisite for producing the
proper length of needle stroke.
From the above described arrangement of cam operated rocker pivotally
connected with the controller lever it results that when the presser arm only is
moved, as by the lift handle, and the machine is at rest, the pivots connecting the
rocker and controller lever become the centre upon which the latter vibrates;
when the presser arm is raised sufficiently high to be unaffected by the feeder and
the machine is running, the controller lever rock shaft becomes the centre upon
which the controller lever vibrates; but when the machine is running and the
presser foot rests upon the work plate or the work, then the action of the feeder
upon the controller lever is counteracted by the action of the controller lever cam
upon the rocker, thus reducing the vibration of the free end of the controller lever
as before explained.
The positive operation of the controller mechanism further renders it necessary
in the event of the presser arm being raised when the action is clamped that some
part of the said mechanism should "give." This "give" is provided by the spring
jointed lever on the presser arm rock shaft before referred to. This lever is made
in two parts, one part being fixed to the said rock shaft and the other part being
pivotted to the first mentioned part and connected by a link with the controller
lever as before described. The two parts are also connected by a spring which
normally maintains a stop on one part in contact with a stop on the other part and
is of sufficient strength to keep these stops in contact and to cause the lever to
act as if jointless when operating the controller mechanism. The said spring will
however yield and permit the stops to move apart and the jointed lever to "give"
should the presser arm be lifted when the action is clamped. This "give" in the
jointed lever further comes into play should it be necessary to raise the presser
arm (as for the introduction or release of the work) when the needles are adjusted
to their highest throw and the controller mechanism has consequently reached the
extreme limit of its movement. The pivotted part of the jointed lever is formed
with an arm extending downwards, which arm, when the needles are adjusted
to their highest throw, comes into contact with a fixed stop. If the presser.
arm is now further lifted the only effect will be to cause the jointed lever to
give."
66
"
Controller mechanism constructed as above set forth need only be clamped
during the time or during a portion of the time the needles are in the work, and
the clamping of the controller action during the rise of the feeder, as in the
arrangement heretofore employed, is dispensed with.
The clamp I employ consists of a lever having a spring tail operated from a cam
on the main shaft, which I call the clamp cam, during the time er during a portion
of the time the needles are in the work. On each side of the fulcrum of this lever
there is pivotted a clamp block between which passes a clamp bar or slide loosely
connected by a link with the controller lever and supported at its free end by a
suitable guide. When the clamp lever is operated by the cam the clamp bar
will be gripped between the clamp blocks which being pivotted and mounted as
described require no adjustment in relation to each other and render the clamp self
adjusting.

page_text: The employment of a clamp bar loosely connected by a link with the con-
troller lever so as to be free to take its own position between the clamp blocks
ensures greater freedom of working. With controller mechanism constructed
according to my invention, the clamping device might be altogether dispensed
with, but I prefer to employ the same as rendering the operation of the machine
more reliable.
I, EDMUND WISEMAN, of Cheapside, Luton, in the County of Bedford,
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 :-
This invention relates to straw plait sewing machines of that class or type
wherein sewing implements or needles attached to a carrier beneath the work plate
are thrust upwards through the work carrying the thread in the form of a loop
and coöperate with one or more looping devices supported above and movable with
the presser foot.
In the operation of machines of this class or type it is essential that the needles
should at each stroke pass through and project beyond the material for a sufficient
distance for the loop of thread to be engaged by the looping devices and since
the material operated upon is usually of varying thickness it is necessary to auto-
matically change the stroke or field of movement of the needles, that is to say,
to increase or lessen it according as the material increases or diminishes in
thickness.
Mechanism known as "controller mechanism "has heretofore been employed for
effecting this result said mechanism being operated by the rise and fall of the
presser arm and constituting a connection between the same and the needle
operating devices whereby the movement of the latter was controlled by that of
the presser arm.
The chief object of my invention is to provide improved controller mechanism
for the purpose above set forth and a distinctive feature of my improved con-
troller mechanism is that the same is so constructed and arranged, as will be
hereinafter fully described, as to be operated positively in both directions both by
the elevation and by the depression of the presser arm, whereas the controller
mechanism hitherto in use was positively operated by the presser arm in one
direction only, and reliance was placed. upon a spring for operating it in the
reverse direction. My improved controller mechanism being positively operated
in both directions as above mentioned is more reliable and efficient in action.
It is obvious that the slight raising and lowering of the presser arm due
to the feed action will more or less affect the controller mechanism and through
the latter the needle operating devices, resulting in the throw of the needles
being constantly and unnecessarily changed, and another object of my invention
is to neutralize the effect upon the needle operating mechanism of this slight
predetermined movement of the presser arm by means of a counteracting movement
imparted to the controller mechanism iu such manner as to prevent any material
alteration of the throw of the needles by said predetermined movement.
Again, in the passage of the needles through the work, especially if it be of a

page_text: character to offer much resistance to such passage, it is often the case that the
presser foot is accidentally raised and the needle operating devices thereby
affected through the controller mechanism thus causing a variation in the throw of
the needles. This is of course very objectionable and as a remedy it is usual to
provide means for automatically locking or clamping the controller mechanism
during the passage of the needles through the work and for releasing such
mechanism when the needles have completed their stroke. It is another object of
iny invention to improve upon the clamping or locking devices hitherto employed
for this purpose.
I will now fully describe my invention and the manner of performing the same
reference being had to the annexed drawings in which similar letters refer to
corresponding parts in all the figures, and wherein :—
Fig. 1 is a plan view of the invention, those parts of the sewing mechanism not
necessary to a clear understanding of the invention being omitted.
Fig. 2 is a vertical sectional elevation on the line - of Fig. 1.
Figs. 3 and 4 are detached views of the controller lever in front and side
elevation respectively.
Fig. is detached view of the controller lever rocker.
Figs. 6 and 7 are detached views showing the spring-jointed lever in front and
side elevation respectively.
Fig. 7 is a detail side elevation of a part of the spring-jointed lever.
Figs. 8 and 9 are respectively plan and front elevations of the devices for
clamping the controller mechanism against movement.
Fig. 10 is a face view of the controller lever cam, and,
Fig. 11 is a detail side elevation of the controller mechanism, the clamping
devices being omitted.
an
a is the main shaft of the machine mounted in suitable bearings in the frame b.
c is the needle carrier rock shaft supported in the bearings c 1, and c 2 is an arm
projecting from said shaft near one end thereof and connected by means of a
link c3 with the needle carrier d. To the other end of the rock shaft c is rigidly
secured the slotted arm c4 in the slot c5 of which the block c 6 is adapted to move
freely. Upon the main or driving shaft a of the machine is mounted
eccentric a provided with the usual strap a 2. Pivotally connected at a 5 with
the sliding block c6 is a lever a 3 extending in position to be operated by the
eccentric a 1. From the above it will be apparent that at each revolution of the
main shaft a the lever a 3 and slotted arm c4 will be lifted and the shaft c caused
to rock. This movement of the shaft c lifts the arm c2 and through link c 3
reciprocates the needle carrier d. The length of the stroke of the needle it will be
noted is determined by the position of the sliding block c6 in the slot c5 of the
arm c4, the nearer said block being to the rock shaft the longer the stroke of the
needle.
The presser aim e is provided with the usual presser foot el and is connected
with the presser arm rock shaft e 2 in turn mounted in bearings e 3. The
presser arm is here shewn as pivotted but it will be understood that the ordinary
reciprocating presser bar may be employed instead, it being only necessary to
connect such a bar to the rock shaft e 2 by means of a lever.
Connected to the sliding block c6 by means of a link * is the controller
lever f.
The upper end of this lever is pivotted at 1 with a rocker arm h secured upon
a rock shaft hand adapted to move therewith. Rigidly secured upon the
presser armn rock shaft e 2 is a spring-jointed two-part lever I which will be
described in detail hereinafter. This lever is connected by means of a link g with
an arm 2 of the controller lever which is operated positively by the rise and
fall of the presser arme through the medium of the rock shaft e 2, lever I and
link
g just described. Connected to the rock shaft is an arm h3 carrying a
friction roller h4 at its end which enters the groove in a controller lever cam / 5
upon the main shaft a.

page_text: From this it will be apparent that if the presser arm be only slightly lifted by
the action of the feed devices, the presser arm rock shaft e 2 will be affected and
the lever I lifted in the direction of the arrow x, Fig. 11 and through the medium
of the link g will swing the lower end of the controller lever f which is pivotally
supported upon the rocker arm hat fl in the direction of the arrow y.
Simultaneously with this operation the controller lever cam 5 is rotated in a
position to lift the end of the arm h3 causing the rock shaft hi and rocker arm h
to be rocked in the direction of the arrow z. This of course moves the controller
lever and changes the plane of its pivotal point the effect of which to move its
lower end in the direction of the arrow w. It will thus be seen that two counter-
acting forces act simultaneously upon the controller lever, each tending to move
its lower extremity in the reverse direction to the other, the effect being naturally
to keep the lower extremity of the lever fin substantially the same position and
consequently the position of the block c6 in its slot is not materially altered and no
appreciable change in the throw of the needles can result from the slight movement
imparted to the controller mechanism by the action of the feed devices upon the
presser arm. If however the presser arm is lifted or depressed to a greater extent
than it would be by the feed devices, the movement of the controller lever f upon
its pivot f1 is so much greater than that for which the shifting of the pivot f1 can
compensate that the lower end of the controller lever is swung in either one
direction or the other and through the link f* alters the position of the sliding
block or adjustable part c6 and changes the throw of the needles in the manner
before explained.
During the passage of the needles through the work if the latter is of a
character to offer resistance to the passage of the needles there is danger of
the presser arm and controller mechanism being accidentally affected and the
needles prevented from moving a proper distance for the loopers to engage the
thread. To overcome all possibility of this, means are provided termed "clamping
meaus for automatically locking the controller mechanism against movement
during the passage of the needles through the work and for releasing said mechanism
at the completion of each throw or stroke of the needles.
"
It will be obvious that various devices may be employed for effecting this, but
I prefer to employ the simple form of clamping means which will now be
described.
Pivotted to the controller lever f (see Figs. 2, 8, and 9) is a link k5 which in
turn is pivotted to a slide k 4 supported near one end in a suitable guide 6 and
near the other end on a plate k hereinafter described. It is obvious from this that
whenever the controller lever is shifted, the slide 4, through the link k 5, is
correspondingly affected, and it will be apparent therefore that if this slidé is
clamped so that it cannot move, the controller lever will not be permitted to móve
either. The devices for clamping the slide k 4 consist of a plate k pivotted upon
the frame b and provided with a spring extension or tail k 1. Upon the plate kare
two separated clamp blocke k 3, between which the slide k 4 extends, and is
permitted to freely move when the plate k is in its normal position. The slight
shifting of said plate to either side of its normal position will bring the clamp
blocks 3 into contact with opposite sides of the slide k 4 and prevent the movement
of the said slide. The automatic shifting of the plate is obtained by means of a
pivotted lever k 7 the upper end of which carries a friction roller k8 (Fig. 10)
which is in position to be engaged by what is termed a clamp cam k 9 mounted upon
the main shaft a. This cam is so formed and adjusted that during each rotation of
the shaft a or during the passage of the needles through the work it will throw an
adjusting screw k 10 of the lever k 7 into contact with the extension or tail k 1 of
the plate k causing the said extension and consequently the plate k to be shifted so
as to clamp the slide k 4.
It will be readily understood that when work which offers but little resistance to
the needles is under operation, clamping means for locking the controller mechanism
may be dispensed with entirely, I prefer however to employ some form of

page_text: clamping means as it renders the action of the machine more certain and
reliable.
The controller mechanism, as before explained, is. positively operated in both
directions and when the controller lever is locked against movement, and the
presser arm is raised, as for instance to remove or insert the work, it is necessary
that some part of the remaining devices of the controller mechanism should
give or yield to compensate for the failure of the controller lever to move.
Various means may be employed for this purpose, and such means may be
located at different points according as convenience demands.
In the present
instance this function is performed by the spring-jointed or two-part lever [
herein before referred to. This lever (see Figs. 6, 7 and 7^) is formed in two
parts the part i being fixed upon the rock shaft e 2 and adapted to move
therewith. The part 1 is pivotted at 2 to the lever i and is provided with a
dependent arm i 6 carrying a lug or stop i 7 which is normally held in contact
with a stop i8 on the part i by means of a spring 13. This spring is secured to a
lateral projection i5 of the part i and bears upon the lower end of the dependent
arm i 6 and said spring is sufficiently strong to hold the stops i7 i8 in contact and
consequently the two parts i il normally move as one. When however the presser
arm is lifted, as for instance by the lift handle e 4, while the controller lever fis
locked, the part i 1, which is connected to the controller lever f by the link 9, is
caused to turn upon its pivot i 2 by reason of the failure of the arm 2 to move.
This causes the spring 3 to yield and results in the separation of the stops i7i8
which are again moved into contact by the action of the spring when the presser
arm is lowered. The necessary upward movement of the presser arm to give the
highest throw to the needles is usually very much less than that required to insert
or withdraw the work, and it is desirable that the needle operating mechanism be
not affected by the movement of the presser arm above a predetermined point.
This is accomplished by the two-part lever I just described by providing the lower
end of the dependent arm i 6 of the part 1 with a stop 19 adapted to make
contact with a stationary bearing c 1 when the sliding block c6 is at or near the
end of the slot c 5 nearest the rock shaft c, or in other words, when the parts are
adjusted to a position to give the needles their highest throw. It will thus be
apparent that if the presser arme be raised after the stop i 9 makes contact with
the bearing c 1 the effect will be to hold the part i 1 practically stationary and as
the part i must necessarily move with the presser arm rock shaft e 2 the stops i7i8
will be separated against the action of the spring i 3.
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 a sewing machine, the combination with the needle operating mechanism
and the presser arm, of controller mechanism intermediate the presser arm and the
needle operating mechanism whereby the movement of the latter is controlled by
that of the former, said controller mechanism being operated positively in both
directions by the clevation and depression of the presser arm, and neaus for
imparting a counteracting movement to the controller mechanism in such manner
as to neutralise the effect upon the needle operating mechanism of the slight
movement of the controller mechanism due to the action of the feed devices upon
the presser arm, substantially as described.
2. In a sewing machine, the combination with the needle operating mechanism
and the presser arm, of the pivotted controller lever, connections between the
latter and the needle operating mechanism, connections between the controller lever
and the presser arm whereby the former is swung upon its pivot by the movement
of the latter, and means for automatically shifting the position of the pivotal point
of the controller lever during its swinging movement whereby the effect of such
movement upon the needle operating mechanism is neutralised, substantially as
described.

page_text: 3. In a sewing machine, the combination with the needle operating mechanism
and the presser arm, of a pivotted controller lever, connections between the latter
and the presser arm whereby the controller lever is swung upon its pivot by the
movement of the presser arm, a rock shaft 1 having an arm h to which the
controller lever is pivotted, an arm 3 extending from sai rock shaft and a cam h 5
on the driving shaft with which cam said arm 3 engages substantially as
described.
4. In a sewing machine, the use in combination with the needle operating.
mechanism and the presser arm, of controller mechanism intermediate the presser
arm and the needle operating mechanism whereby the movement of the latter is.
controlled by that of the former, sail controller mechanism embracing a two-part
lever having a yielding connection between its parts, and means for automatically
lecking the controller mechanism against movement during the passage of the
needles through the work, substantially as described.
5. In a sewing machine, the use in combination with the needle operating
mechanism and the presser arm, of controller mechanism intermediate the presser
arm and the needle operating mechanism whereby the movement of the latter is
controlled by that of the former, said controller mechanisin embracing a two-part
lever provided with a yielding connection between its parts and with a stop.
adapted to make contact with a stationary bearing upon the lever being moved a
predetermined distance, substantially as described.
6. In a sewing machine, the use in combination with the needle operating
mechanism and the presser arm, of controller mechanism intermediate the presser-
arm and needle operating mechanism whereby the movement of the latter is.
controlled by that of the former, said controller mechanisin embracing a two-part
lever, the parts of which are pivotally connected and provided with stops, a spring
for holding said stops normally in contact, and means for automatically locking
the controller mechanism against movement during the passage of the needles
through the work, substantially as described.
7. In a sewing machine, the use in combination with the needle operating
mechanism, the presser arm, and controller mechanism intermediate the presser
arm and the needle operating mechanism whereby the movement of the latter is
controlled by that of the former, of locking mechanism comprising a rotatable-
plate separated clamping blocks, a connection intermediate the controller
mechanism and locking mechanism and exten·ling between said clamping
blocks, and means for automatically. turning the rotatable plate, substantially as.
described.
8. In a sewing machine, the use in combination with the needle operating
mechanism and the presser arm, of controller mechanism intermediate the presser
arm and needle operating mechanism whereby the movement of the latter is
controlled by that of the former, said controller mechanism embracing a pivotted
controller lever, a rotatable plate carrying separated clamping blocks and provided
with an extension, a slide extending between said blocks, a link connecting the
slide and controller lever, a driving shaft, a cam mounted thereon, and a lever-
actuated by said cam and adapted to make contact with the extension of the-
rotatable plate, substantially as described.
11
1000
E. P. ALEXANDER & SON,
Chartered Patent Agents,
19, Southampton Buildings, Chancery Lane, London, W.C., Agents..