Improvements in Machines for Sewing Button Holes.
Year: 1895

page_text: Date of Application, 6th Sept., 1895-Accepted, 4th Apr., 1896
Improvements in Machines for Sewing Button Holes.
1 RICHARD MATTHEW MELHUISH, of 49 Fann Street, Aldersgate Street in
the City of London, Manufacturer 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 :-
My invention relates to improvements in machines for sewing straight button
holes before cutting the same.
Such machines consist of a sewing machine of any ordinary type using a straight
needle and provided with a vibrating work-plate upon which the work is clamped,
said plate being vibrated so as to bring the work into such positions as to cause
the needle to enter the work at the edge of the intended button hole and at a
distance therefrom alternately, and the plate being also fed to and fro so as to
cause the stitching to be done along the two sides of the intended button hole, the
extent of the vibration being increased and the feed being arrested on reaching
the ends of the button hole so as to cause barring" stitches to be made completely
across the ends of the hole.
1
The work plate when brought into proper positions to cause the stitching to be
performed along the two sides of the button hole, is vibrated to the proper extent to
produce such stitching or to produce the "barring " stitches through the medium of a
three-faced cam carried by a rod which being reciprocated in the longitudinal
direction is caused, by the action of the cam against a fixed abutinent, to reciprocate
also laterally and to impart such lateral motion to the work plate which takes a
bearing against the rod. The traverse of the work plate to and fro successively
in opposite directions as the stitching of the two sides of the button hole progresses
is produced by a feed screw working through a nut connected to the work plate
and operated intermittently from the main shaft with which it is geared so as to be
operated first in the one and then in the other direction, the throwing of the feed
screw into gear for motion in the one or other direction, or out of gear to arrest
the feed when the "barring" operation is in progress, depending on which face of
the cam already mentioned is in position to impart vibratory motion to the feed
plate.
The present improvements relate more particularly to certain details of
construction which, in so far as they relate to parts in motion, have for their
principal object to ensure such smoothness and certainty of action and absence of
vibration at high speed as to enable the machine to satisfactorily stitch the hole
after cutting, as well as before cutting, which has not heretofore been possible in
such machines, the improvements also greatly conducing to the durability of the
machine.
The improvements relate, first, to a spring guard plate whereby to keep the goods
free from the work plate vibrating cam and feed screw, the said guard plate acting
also as a means of keeping the shuttle race cover from becoming jarred out during
the working of the machine; secondly, to the abutment for the work plate vibrating
cam; thirdly, to the construction of the feed screw nut and to its connection with
the work plate; fourthly, to an improved construction of the work clamp whereby
it is rendered self-adapting to work of irregular thickness; fifthly, to the adjustable
bearing of the feed screw shaft whereby to avoid the wearing of flats thereon;
sixthly, to the teeth of the crown wheels which drive the feed screw shaft pinion;
seventhly, to the brake for the thread tension screw; and, lastly, to the connection

page_text: between the work plate vibrating cam rod and the lever from which it derives
motion, and to the means whereby a special form is given to a bearing forming part
of said connection.
These improvements will be illustrated both as applied to the machine ant
also in detail in the accompanying drawings, forming part of this Specification,
wherein
Figure 1 is a front elevation of the machine and Figure 2 a horizontal sectional
plan of the same, the needle arm being removed.
Figure 3 is an elevation of one end of the frame of the machine, shewing the
spring guard plate and adjacent parts, drawn to the same scale as Figures 1 and 2
-riz, about four-fifths of full size.
Figure 4 is a part plan and Figures 5, 5 and 6 are sectional elevations o
lines 5-5, 5-5, and 6-6 (Figure 4) respectively, of the work plate, shewing
the feed screw nut and its connection with the work plate.
Figure 7 is a part plan and Figure 8 a part sectional elevation shewing the
pinion on end of the feed screw shaft, the crown wheels which drive same, and the
adjacent bearing for the end of the feed screw shaft.
Figure 9 is an end elevation of the same shaft shewing the pinion and bearing
already referred to.
Figure 9 is a transverse sectional elevation of the same bearing, illustrating the
method of taking up wear therein.
Figure 10 is a plan and Figure 11 a part rear elevation, both sectional, shewing
the elbow lever which gives motion to the work plate vibrating cam rod, the
adjacent end of said rod, and its connection with the feed screw shaft.
Figure 12 is a part sectional side elevation of the elbow lever and Figure 13
illustrates the action of the eccentric and link connecting the aforesaid cam rod with
the feed screw shaft.
Figure 14 is a plan of the work plate vibrating cam and its abutment.
Figure 15 is a rear elevation of said abutment and Figure 16 an end elevation of
the cam itself.
Figure 17 is a plan (with presser cam lever displaced for the sake of clearness)
and Figure 18 a part sectional side elevation of the work clamp in the closed
position.
Figure 19 is a part longitudinal sectional elevation of the clamping jaw,
illustrating the action of the jaw in clamping work of irregular thickness.
The figures from No. 4 to No. 19 inclusive, are drawn to a scale of about
double full size. The same letters of reference denote like parts in all the
figures.
A is the vibrating work plate having an oblong bevelled aperture a in which the
work is secured by the work clamp B, the plate A resting in front on the arm C
of the machine frame in which the shuttle works and receiving vibratory motion
transversely to the length of the slot a through the medium of a three-faced cam D
acting against a fixed abutment E, the cam D being carried by a rod F against
which a bracket faffixed by a flange to the underside of the plate A is caused to
bear. The bracket is of semi-tubular section and embraces the rear side of the
rod F with which it is held in contact by a spring G fixed to a lugg on the underside
of the plate A and bearing by its thickened ends g'against the front of the machine
arm C. The cam rod F receives longitudinal to and fro motion from an elbow
lever H pivoted at to the machine frame and actuated by a stud and friction
roller at its other end engaging in a cam groove i in a spur wheel I in gear with
a pinion on the main shaft J. The cam D has three inclined faces 1, 2, 3, either
of which may be brought into contact with the abutment E by turning the rod F·
and cam D about their longitudinal axis, the two opposite faces 1 and 3 of the cam
being inclined at the same angle to the rod F but situated at different distances
from its centre line so that the work held by the clamp B will be shifted so as to
bring the stitching at the one or other side of the button hole according as face.1
or face 3 is in contact with the abutment E. The intermediate face 2 is inclined

page_text: at such a greater angle than the other faces 1 and 3 that the same amount of
longitudinal motion of the rod F will cause the plate A to be vibrated to twice the
extent of the vibration produced by either of the faces 1 and 2 and will thus result
in stitches of double the length being made for "barring" the ends of the button
hole. The cam rod thus receives longitudinal motion by the rocking of
lever H and also a slight angular motion about the end which is attached to
said lever, the angular motion being in a horizontal plane and being produced by
the inclined face of the cam sliding against its abutment E.
The feed motion of the plate A in two opposite directions coinciding with the
direction of length of the aperture a is obtained by means of a feed screw shaft K
mounted in the frame of the machine and working through a correspondingly
threaded nut L forming part of a supporting carriage Mapo which the rear part
of the work plate A rests, the carriage M having oppositely extending arms m
which by bearing against the underside of the plate A prevent the rotation of the
nut with the feed screw shaft K whilst freely permitting the plate A to vibrate
laterally. The plate A is connected to the nut L by means of a stud / fixed thereto
and carrying a die block n free to slide in a slotted link N fixed upon the plate A
over an aperture therein, the link N being secured in such an oblique position as to
counteract the effect of the angular motion of the cam rod F upon the direction
of vibration of plate A and cause said plate to vibrate in straight lines approxi-
mately perpendicular to the length of the button hole so that the barring stitches
when no feed takes place will be as nearly as possible truly at right angles across
the ends of the hole. By means of this stud die block and link connection with the
plate A the latter is caused to participate in the traverse of the nut L along the
feed screw shaft K produced by the intermittent rotation of the latter in the one
or other direction by a pinion on the end of the screw shaft being engaged by
the teeth o of one or other of two opposed crown wheels O fast upon the main
shaft J, with either or with neither of which, the pinion k may be geared according
as it is required to feed the work plate A in the one or other direction for working
along the one or the other side of the button hole, or to interrupt the feed when
barring the ends of the hole, as the case may be. The gearing of the feed
screw pinion k with the one or other, or with neither, of the wheels O depends on
which of the cam faces 1, 2 or 3 is in operative position against the abutment,
that end of the feed screw shaft which carries the pinion & being (simultaneously
with the alteration of the cam face) shifted laterally by an eccentric P on the
cam rod F acting on a link p attached to a pair of sleeve bearings p' through
which the plain part of the screw shaft K passes. The action of the eccentric P
is illustrated more particularly in Figure 13 which is self-explanatory, the three
positions 1, 2, 3, of the centres being the positions occupied when the three
similarly numbered faces 1, 2, 3, of the cam are in operative position.
It being necessary that the feed of the work in the direction of the length of the
button hole should be intermittent, taking place only between the formation of two
successive stitches, each of the wheels Ŏ is provided, not with the full possible
number of teeth around its circumference but, only with so many as may be
necessary to produce between two successive stitches the required amount of
rotation of the feed screw shaft, the pinion being driven so long as the teeth o
continue to engage with it, but remaining stationary during the pause due to the
passage of the toothless, and therefore inactive, portion of the wheel O. As the
partial rotation of the feed screw shaft necessarily takes place very suddenly, it is
important to ensure the accuracy of position of the pinion with regard to the
crown wheels and to guard against any want of accuracy due to slackness caused
by wear of the sleeves p' about the shatt K. With this object the sleeves p' are
made self-gripping by being bored out of the solid, to a rather smaller diaineter
than that of the shaft K and then split longitudinally at p to enable them to open
out sufficiently to be slipped on to the shaft.
The wheels are crown wheels, that is to say, each consists of a dise from
the face of which the teeth o project so as to be capable of engaging with the spur

page_text: teeth of the feed screw shaft pinion k. The teeth o (of which in the example shewn
in the figures there are two to each crown wheel) preferably consist each of a stud
passing through the disc of the wheel and secured in position by a binding
screw. The projecting point of each stud is hollowed out, as at o², upon the side which
engages with the pinion k so that the acting flank of the tooth thus formed is
approximately parallel to the flank of the pinion tooth at the moment of striking
it, whereby a sufficient amount of wearing surface of the tooth is ensured. This
acting flank of the tooth is rounded convexly, as shown by the dotted lines o³,
Figure S, so as to act with a rolling motion on the tooth of the pinion as the two
change their relative positions by their rotation in planes at right angles to each
other. The rear flank of the tooth o is also bevelled as at o, so as in working to
clear the next following tooth of the pinion k; the shape thus given to the point of
the tooth o being approximately that of a hook.
k
The feed screw shaft K is pivoted at the one end in the arm C' of the frame and
is mounted at the other end (which carries the pinion ) in a brass bearing block R
fitted to slide in a horizontal slot in the small standard R' so that the screw shaft
itself will not be liable to have flats worn upon it through being shifted laterally,
as would otherwise be the case; and by this means more equal and steady running
is ensured.
The bearing block R which is confined within the slot by the upwardly pro-
jecting end flanges, is split lengthways on the underside as at, and has a
shallow depression 3 formed upon its upper surface for the reception of oil which
thus forms a cushion to deaden the shocks caused by the lifting tendency due to
the direction of rotation of the crown wheel O. When the journal wears, as
illustrated in an exaggerated form in Figure 9, the wear is taken up as there
shewn by merely pinching together the slightly separated edges of the slit 2.
The effect of this is to provide a ready means of correcting not only the internal
wear of the journal but also the external wear of the block R due to its lateral
movement in the slot 2, as is also illustrated in Figure 94, where it will be seen
that the pinching together of the edges of the slit depresses the outer lower
edges of the block R causing them to take a fresh and steady bearing against
the bottom of the slot; the efficiency of the top bearing surfaces (consisting of
the raised edges of the depression, and the enclosed oil cushion) remaining
unimpaired.
In order to prevent irregularity of feed by reason of acquired momentum of the
serew shaft, the latter has a collar P upon it which is encircled by an adjustable
brake strap P affixed to the machine frame C'.
In order to prevent the fabric being soiled by contact with the cam D or the
feed screw K, a guard plate Q is provided which serves also as a means of pre-
venting the sliding cover c of the shuttle race from gradually sliding out which
it is liable to do by the unavoidable jarring of the parts when the machine is at
work. To adapt it to answer this double purpose the guard plate is formed by
an upwardly curved strip of spring steel rivetted by one end to the shuttle race
cover c and extending rearwards so as to lie over the cam D and the part of
the feed screw K at which the brake P2 is situated, the downwardly directed
free end of the spring plate Q bearing against the inner side of the return end C
of the machine frame so as to oppose (by spring pressure thereon) any tendency of
the cover c to slide out of its grooves, whilst admitting of said cover being easily
withdrawn by band to give access to the shuttle.
The abutment E of the cam D is a roller of preferably triangular section
pivoted on a pin mounted in the part of the machine frame immediately in rear of
the arm C. Being pivoted it is self-adjustable to suit the inclinations and move-
ments of the different faces of the cam and having several flat faces it presents
a series of easily changeable wearing surfaces so that its durability is much
greater than would be that of a fixed abutment or even of a cylindrical roller.
The feed nut L is of peculiar construction, being formed one half of metal and
the other half of gutta-percha, leather, wood, horn, or other material capable of

page_text: being softened so as to admit of the counterpart of the thread of the screw
spindle K being formed by pressure. The mode of making the nut is as follows,
and the object to be attained thereby is to avoid shake, enable slack to be taken
and ensure such "deadness of motion of the feed screw shaft as to prevent
liability of the latter over-running its actuating gear by its acquired momentum,
even although no brake were provided.
up,
It is then
The nut is forged solid and drilled and tapped in the usual way.
divided or slotted longitudinally so as to remove about one half the circumference
of the nut for its full length and the part so removed is replaced by a grooved
piece of gutta-percha, or other material L' which is capable of being softened by
hot water so that when clamped in place against the liner 12 by the clamping
screws and angled backing plate 13, it will be caused to receive the impression of
the thread of the screw shaft K. The impressible part of the nut is thus capable
of being tightened up by said screws 1, as the nut wears so that slack can
always be taken up and "deadness" of action ensured whilst renewal is easily
effected by softening the material in water and impressing a fresh thread when
required.
In order to afford in addition a long and steady bearing for the nut L upon the
feed screw shaft K the former is provided with a sleeve m³ formed upon an
extension of the carriage M and adapted to embrace and slide upon the plain
portion of the screw shaft. This sleeve is first bored out to a rather smaller
diameter than that of the plain part of the screw shaft K and then slit lengthways
as at m², shewn in Figure 54, the sleeve being thus rendered capable of sufficient
spring to permit of its being slipped over the shaft, whose plain portion it will
grasp forcibly enough to steady the motion of the nut upon the screw. Any
wear in this sleeve can be readily taken up by squeezing together its divided
sides.
As the traverse of the feed screw nut generally takes place upon the same
portion of the threaded part of the feed screw, there is liability of shoulders being
formed on the feed screw at the extremities of the traverse, so that when a greater
traverse than usual is required (as for working an extra long button-hole) there is
danger of the nut becoming jammed against the shoulders thus formed on the screw.
To avoid this I make the middle part of the screw which is most subject to wear of
slightly larger diameter than the extremities which are tapered, the nut being of
such length relatively to that of the cylindrical middle portion of the screw that
the minimum traverse of the nut along the screw must necessarily cause it to
overlap the tapered end portion of the screw and thus avoid liability of a shoulder
being worn either on the nut or the screw.
The work clamp is made of spring steel and consists of an open rectangular
clamping jaw B, the lower edges b of which press the fabric (X, Figure 19,) into
the bevelled or flaring aperture a of the work plate A, and this jaw is formed on
the end of a lever B₁ having its fulcrum at the opposite end and pressed upwards
by a spring and downwards by a cam lever S pivoted at s upon a nut T
screwing upon a screw stud t passing through the lever B¹ and fixed to the
plate A.
In order to enable the clamping jaw to grip the work uniformly, notwithstanding
that the latter may be of unequal thickness, as for instance when the button hole is
to be made near a bein where the inturned edges of the fabric increase the
thickness towards one end of the button hole, the part of the lever arm B' between
the point of application of the presser lever cam S and the clamping jaw B is slit
in the longitudinal vertical plane, as shewn at 63, the slit extending through the
adjacent side of the clamping jaw the opposite ends 66 of which are thus to a
certain extent independent so that together with the separate members of the split
lever to which they are immediately attached each is free to yield slightly to suit
any irregularity in the thickness of the fabric X as illustrated in the detail view
Figure 19.
The thread tension regulating mechanism is of the type consisting of a leather

page_text: strap U encircling a pulley U' on the thread reel spindle u and attached to a
serew passing through a nut e fixed to the frame of the machine, as shewn in
Figure 1. Instead, however, of the lock nut usually employed for securing the
screw in a position corresponding to any required tension I make use of a half
but V pressed against one side of the screw V by means of a spring . This
arrangement whilst preventing any alteration of the thread tension through jarring
due to the running of the machine enables the tension to be altered or adjusted
when required, without the necessity of unclamping and the risk of omitting to
re-clamp the lock nut.
The work plate vibrating cam rod F receives its reciprocating movement in the
longitudinal direction from the elbow lever H already described, through two
collars upon said rod bearing against the opposite faces 2 of the lever wherein
the end of the rod is supported by the portion thereof, situated between the
collars, passing through an aperture of corresponding size in the lever, as shewn.
The collars f being preferably of flat disc shape it is necessary in order that they
may maintain a constant bearing against the faces of the lever during the
combined angular movements of the cam rod F in a horizontal plane and of the
lever H in a vertical plane, that the said faces should be specially shaped to
accommodate these movements. This is effected by the action of a pair of milling
cutters of the same, or slightly larger, diameter than the collars and mounted
upon a shaft in the same relative positions as the collars, this shaft being
temporarily substituted for the cam rod F and caused to rotate whilst both the
shaft itself and the lever H receive respectively their proper angular movements
as when the machine is at work.
In order that the cam rod F (or the substituted shaft which carries the milling
cutters) may be more readily inserted in, or removed from, its position in the
lever H, the bearing in the latter is divided and furnished with a removable cap H
as shewn more particularly in Figure 12.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
1. In a button-hole sewing machine of the kind described, the combination, with
the shuttle race cover slide, of a spring guard plate fixed thereto, adapted to cover
the work plate vibrating cam and feed screw brake and to cause the cover slide to
jam in its groove so as to prevent it sliding out during the working of the machine,
as specified.
2. In a button-hole sewing machine of the kind described, the combination, with
the work plate vibrating cam, of an abutment consisting of a roller with flats
formed on it so as to be self-adapting to the inclination and movements of the cam
and afford an extended and renewable wearing surface, as specified.
3. In a button-hole sewing machine of the kind described, constructing the feed
screw nut partly of metal tapped in the ordinary way and partly of an inserted and
renewable piece of soft material such as gutta-percha, leather, or wood clamped
tightly against the screw shaft so as to be thereby impressed with the screw thread,
substantially as and for the purpose specified.
4. In a button-hole sewing machine of the kind described, the combination, with
the nut constructed as described, of a split sleeve adapted to tightly embrace and
slide upon the plain portion of the feed screw shaft substantially as and for the
purpose specified.
5. In a button-hole sewing machine of the kind described, the feed screw having
its threaded portion cylindrical at the middle and slightly tapered down at each
end in combination with a nut of such relative length as to overlap the tapered
portions of the screw in making its minimum traverse, as and for the purpose
specified.
6. In a button-hole sewing machine of the kind described, the combination, with
the nut constructed as described, of horizontal steady arms projecting from both

page_text: sides of the nut and bearing against the underside of the vibrating work plate for
supporting the plate and preventing the nut turning with the feed screw, as
specified.
7. In a button-hole sewing machine of the kind described, the combination, with
the stud on the feed screw nut and with the slot link on the vibrating work plate,
of a die-block receiving the stud and fitting such link, as and for the purpose
specified.
8. In a button-hole sewing machine of the kind described, the bearing block in
which the shifting end of the feed screw shaft is mounted, constructed with an oil
cushion chamber at the upper side, and split at the lower side and fitted to move
between the top and bottom guides of a horizontally slotted standard, substantially
as and for the purpose specified.
9. In a button-hole sewing machine of the kind described, the acting faces of the
teeth of the feed screw operating crown wheels made of the combined hooked and
convex form described for the purpose specified.
10. In a button-hole sewing machine of the kind described, splitting the jaw-
carrying arm of the work clamp longitudinally as described to enable the jaw to
yield and adapt itself to unequal thickness of fabric beneath the two ends of the
jaw, as specified.
11. In a button-hole sewing machine of the kind described, shaping the surfaces
of the cam rod vibrating lever which engage with the collars on the cam rod, by
means of milling cutters mounted on a shaft which is temporarily substituted for
the cam rod, and caused to rotate whilst receiving an angular motion similar to
that of the cam rod, the lever at same time receiving its proper angular motion so
that the cutters acting on the opposite faces of the lever will bring said faces to
such form as to allow flat collars on the cam rod to maintain a constant bearing
against said faces when the machine is at work, as specified.
12. In a button-hole sewing machine of the kind described, the sleeves of the
eccentric rod which embrace the feed screw shaft split longitudinally so as to
enable a tight fit to be constantly maintained, as described.
13. In a sewing machine, the locking device for the thread tension adjustment
screw, consisting of a half nut carried by a spring and pressed by it into
engagement with the tension adjustment screw, substantially as described.
Dated this 5th day of September 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.