IMPROVEMENTS IN SEWING MACHINES, PART OF WHICH IMPROVEMENTS IS ALSO APPLICABLE TO OTHER MACHINERY IN WHICH ROTARY MOTION IS TO BE CONVERTED INTO RECIPROCATING MOTION
Year: 1869

page_text: LETTERS PATENT to Robert Bagshaw Plum, of the City of Worcester,
Cutler, and Robert George, of the same Place, Machinist, for the
Invention of "IMPROVEMENTS IN SEWING MACHINES, PART OF WHICH
IMPROVEMENTS IS ALSO APPLICABLE TO OTHER MACHINERY IN WHICH ROTARY
MOTION IS TO BE CONVERTED INTO RECIPROCATING MOTION."
Sealed the 26th November 1869, and dated the 4th June 1869.
PROVISIONAL SPECIFICATION left by the said Robert Bagshaw Plum
and Robert George at the Office of the Commissioners of Patents,
with their Petition, on the 4th June 1869.
We, ROBERT BAGSHAW PLUM, of the City of Worcester, Cutler, and
ROBERT GEORGE, of the same Place, Machinist, do hereby declare the
nature of the said Invenion for "IMPROVEMENTS IN SEWING MACHINES
PART OF WHICH IMPROVEMENTS IS ALSO APPLICABLE TO OTHER MACHINERY IN
WHICH ROTARY MOTION 18 TO BE CONVERTED INTO RECIPROCATING MOTION," to
be as follows:-

page_text: numerous cams or excentrics is dispensed with, and the crank, crank
pin, or driving power communicates motion by means of levers and
connecting rods or links with or without bell cranks. The needle bar is
worked by a motion of alternate pulling and pushing; it receives reci-
procating action by a bar or other appliance working longitudinally of
the arm of the sewing machine, its motion being in a direction at right
angles to the motion of the needle bar. For instance, the needle bar
may be worked by a duplex lever actuated by a link operated by a bell
crank; or cords working over a pulley and connected with a rocking
lever may impart similar motion; or it may be effected by a link and
vibrating bell crank, or by equivalent mechanical arrangements effecting
the push and pull of the needle bar in such manner. Two stitches may
be made to each revolution of the driving crank by causing the duplex
lever or a connection thereof to draw in within the line of or the
inner side of the needle bar at each inner stroke, and travels to points
equidistant of the needle bar on cach side thereof.
A pushing and pulling motion or arrangement for obtaining such
motion and a duplex lever, as above described, may be used for working
the shuttle bar, and also for the feed motion. I use a hollow-stemmed
foot presser or attach the foot presser to or form it on a tube surrounding
concentrically the needle bar, and capable of being turned thereon, so
that the needle may always be over the centre of the hole of the foot
presser whatever the direction of feed. Fellers, hemmers, or other
appendages may be attached to the foot presser, so that they will work
in any direction of feed, the needle being always in proper position with
regard to the hole of the foot presser. The piece containing the throat
hole, through which the needle passes, may be made in a piece with or
form part of the shuttle race, thus allowing of the use of a shorter
needle. Instead of screwing the working parts of the machine to a table
or stand it may be fitted into and held in the same by a dovetail fitting
or joint so as to be steadily retained, but easily detachable. The stand
or frame may have three wrought-iron legs without feet.
These are
connected by a stay and have a flange or lip at top.
An arrangement for winding the shuttle spools is constructed by using
a thread guide wire or pin vibrating on a centre. This guide, which is
actuated by studs on a wheel driven by another wheel which actuates
the spool, is bent into a double curved form, that is to say, it has a
similar curve at both limbs or ends; such curve is formed by measuring

page_text: the differences of longitudinal distances of intervals obtained by dividing
an imaginary circle into spaces by lines drawn from equidistant points on
its circumference; the two points converge to one point at one end, and
diverge at the other ends, the object being to compensate for the defects
or differential motion of the thrust or throw of the crank, thus equalizing
its motion or rendering it uniform. The same object may be effected by
fixing on the guide a disc or plate, in which is formed an aperture of
a somewhat diamond or lozenge shape, but having edges curved in
manner above described; in this aperture is a moveable plate of shape
corresponding with that of the aperture but smaller, so that its ends
rest upon the sides of the aperture; space is left on each side of such
moveable piece for a crank pin (fixed on a wheel) to work therein, after
working on one side thereof it pushes back the plate so as to work on
the other side thereof.
The two arrangements last described may be applied to machinery
other than sewing machines, when rotary motion has to be converted
into reciprocating motion by causing the wire disc or like contrivance to
work in slides, or guides, or the like.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Bagshaw Plum and Robert George in the
Great Seal Patent Office on the 4th December 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
BAGSHAW PLUM, of the City of Worcester, Cutler, and ROBERT GEORGE
of the same Place, Machinist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of June, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Robert Bagshaw Plum and Robert
George, Her special licence that we, the said Robert Bagshaw Plum
and Robert George, our executors, administrators, and assigns, or such
others as we, the said Robert Bagshaw Plum and Robert George, our
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,

page_text: or
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN SEWING MACHINES, PART OF WHICH IMPROVEMENTS IS ALSO APPLICABLE то
OTHER MACHINERY IN WHICH ROTARY MOTION IS TO BE CONVERTED INTO RECI
PROCATING MOTION," upon the condition (amongst others) that we, the
said Robert Bagshaw Plum and Robert George, our executors
administrators, by an instrument in writing under our or their hands
and seals, or under the hand and seal of one of us or them, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said Robert Bagshaw Plum and
Robert George, do hereby declare the nature of the said Invention, and
in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, reference
being had to the accompanying Drawings, and to the letters and figures
marked thereon, that is to say:-
:
This Invention principally refers to the mode of driving the needle
bar and certain other working parts of sewing machines whereby the use
of numerous cams or eccentrics is dispensed with, and the crank, crank
pin, or driving power communicates motion by means of levers and
connecting rods or links (with or without bell cranks). The needle
bar is worked by a motion of alternate pulling and pushing; it
receives reciprocating action by a bar or other appliance working
longitudinally of the arm of the sewing machine, its motion being
in a direction at right angles or nearly so to the motion of the needle
bar. For instance, the needle bar may be worked by a duplex lever,
which is actuated by a link operated by a bell crank; or cords working
over a pulley and connected with a rocking lever may impart similar
motion; or the working may be effected by a link and vibrating bell
crank, or by equivalent mechanical arrangements effecting the push
and pull of the needle bar in the above-described manner. Two stitches
may be made to each revolution of the driving crank by causing the
duplex lever or a connection thereof to draw in within the line of (or to
the inner side of) the needle bar at each inner stroke, and it travels to
points equidistant of the needle bar on each side thereof.

page_text: A pulling and pushing motion or arrangement for obtaining such
motion and a duplex lever as above described may also be used for
working the shuttle bar, and also for effecting the feed motion. I use
a hollow stemmed foot presser, or attach the foot presser to or form it on
a tube surrounding the needle bar concentrically, and capable of being
turned thereon, so that the needle may always be over the centre of the
hole in the foot presser whatever may be the direction of feed. Fellers,
hemmers, or other appendages may be attached to the foot presser, so
that they will work in any direction of feed, the needle being always in
proper position with regard to the hole of the foot presser. The piece
containing the throat hole through which the needle passes may be made
in a piece with or form part of the shuttle race, thus allowing of the use
of a shorter needle. Instead of screwing the working parts of the
machine to a table or stand they may be fitted into and held in the table
or stand by a dovetail fitting or joint, so as to be steadily retained but
easily detachable. The stand or frame may have three wrought-iron
legs without feet. These are connected by a stay, and have a flange or
lip at top.
An arrangement for winding the shuttle spools is constructed by using
a thread guide, wire, or pin vibrating on a centre. This guide, which is
actuated by studs on a wheel driven by another wheel which actuates
the spool, is bent into a double curved form, that is to say, it has a
similar curve at both limbs or ends; such curve is formed by measuring
the differences of longitudinal distances of intervals obtained by dividing
an imaginary circle into spaces by lines drawn from equidistant points
on its circumference. The two curves or limbs of the curves converge to
one point at one end and diverge at the other ends, the object being to
compensate for the defects or differential motion of the thrust or throw
of the crank, whereby its motion is equalized or rendered uniform. The
same object may be effected by fixing on the guide a disc or plate in
which is formed an aperture of a somewhat diamond or lozenge shape,
but having edges curved in manner above described. In this aperture
is a moveable plate of a shape corresponding with that of the aperture
but of smaller superficial area than it, so that while its ends rest upon
the sides of the aperture space is left on each side of such moveable
piece for a crank pin (fixed on a wheel) to work therein. After working
on one side of the plate the crank pin pushes the plate so that it
works on the other side thereof.

page_text: The two arrangements last described may be applied to machinery
other than sewing machines when rotary motion has to be converted
into reciprocating motion. The wire or the disc or like contrivance may
be caused to work in slides, guides, or the like. In the last-named
instance it will have a rectilinear or nearly rectilinear motion.
The accompanying Drawings exemplify a sewing machine constructed
according to our improvements.
Figures 1 and 2 are side elevations of a sewing machine with our
improvements applied. Figure 1 shews the position of the parts when
the needle is depressed, and Figure 2 their position when the needle is
elevated. Figure 3 is an elevation of the opposite side of the machine,
shewing the thread supply arrangements; Figure 4 is a front end view
and Figure 5 a back end view of the machine.
A is a revolving driving shaft, to which continuous rotary motion is
communicated by a pulley and driving belt, or by toothed gearing or
other ordinary arrangements. On this shaft is a crank arm A¹ with
crank pin A. This crank arm communicates a rocking motion by
means of a link B to a bell crank C, which is centred and rocks upon a
screw stud C* driven into the casting Z. The crank C is connected with
and communicates motion to an arm or link D, which lies and works
longitudinally of the arm or casting Z of the machine, and com-
municates motion to a duplex jointed or compound lever E, F, to
which it is jointed. The link or arm D works on pins c, c, one at
each end. One end of the bell crank C is jointed to the arm D by
the pin c, and the arms E, F, which compose the compound or duplex
lever E, F, are jointed together at their contiguous ends or point of
junction by the pin e³. Thus a reciprocating motion lengthwise of the
machine is communicated to the arm or link D by means of the con-
nexions A¹, A, B, C, and from this link or arm motion is communicated
to the duplex lever E, F. The arms or limbs of the bell crank C and of
the lever E, F, may be made double, as shewn in Figures 4 and 5.
The
lever E, F, consists of two arms jointed at the ends, as shewn and described.
The upper arm E of the lever E, F, is connected with the machine
casting Z by the pin H, and the lower arm F of the lever is connected
with the needle bar I by the pin or joint G; or the same effect may be
obtained by connecting the upper arm E of the lever E, F, with the
needle bar, and the lower arm F with the casting Z. The lever E, F,
communicates an up-and-down motion to the needle bar I, and works at

page_text: right angles or nearly so to such bar, varying its angle thereto with its
motion. I is the needle bar, which is kept in a vertical position by
passing it through holes f, k, in the casting. It is prevented from
turning round by the screw pin G, which is firmly attached to it, and
runs up and down in a slot G₁ in the casting; L is a spring acting
upon the foot presser V to keep it down on the work; M is the lifter,
and M handle of the lifter; N is a link, which is connected with the
crank pin A', and which gives oscillating motion to a bell crank O,
which rocks upon a screw O fixed in the casting or frame of the
machine. This crank communicates motion by a link P to a sliding
rod Q, which slides to and fro through snugs Q', Q, cast on the bottom
of the machine. This rod Q carries the shuttle carrier R. S is a lever
which oscillates upon the screw O*, and receives motion from the link B
by means of a stud s* which works in a slot in the link B. The lever S
acts upon an inclined portion of a lever T, which has feed teeth at
its other end. This lever gives the necessary forward motion to the feed
bar. The feed bar is lifted by a projection U in a piece with or fixed to
the shuttle carrier. V is the foot presser, which is formed as a flat plate
at its upper part, as shown in Figure 3; it carries a ring or ferrule V*,
which slides on a leg or portion of the frame or casting. It is concentric
with the hole through which the needle bar slides. The lower part of
the foot presser which carries the foot may be slidden on to this ring or
ferrule, and it is kept in place by a screw V*. If the machine be made
to feed in more than one direction any ordinary appliance or appendage
to sewing machines, such, for instance, as a feller or hemmer fixed on
the foot may by turning the foot round on its ferrule at V and
tightening a set screw be made to work in any direction in which the
machine will feed (as such feller or appendage will move with the foot
presser). W, Figure 3, is a moveable forked stop centred on a pin w
having a guide eye w³; at its end it makes one of the thread guide
eyes by its own weight retain the slack thread, and prevent it from
twisting, so that it may be out of the way of the needle until the latter
has entered the fabric; w is a stop on the casting Z, which limits the
travel of the piece W, but allows it a slight play. This guide is move-
able, so that it may act by its own weight in such manner as to prevent
the slack thread getting round the needle. Thus when the needle bar
descends it keeps the thread tight until the needle has entered the fabric,
when shuttle is passing through loop it rises easily, in order to force or
slack the needle thread for the passage of the shuttle. When needle bat

page_text: rises the play of the guide is limited sufficiently to retain new thread
while needle bar tightens stitch. The upper part of the foot presser V
is held in place by a screw I, Figure 3, which passes through a slot in.
the face of the presser, and is fixed to the casting. M³, ordinary tension
apparatus; M', spool of thread; R' is a spring which forces or restores
the feed bar backward and downward; R is an eccentric which limits or
regulates the back throw of the feed bar, and thus regulates length of
stitch.
Instead of the above described arrangement for communicating motion
to the needle bar, we sometimes use a modification shown in Figure 8,
in which the needle bar is worked by cords X, X, running over a
pulley F, and attached at one end to the rocking lever C held to the
casting by screw C" on which it rocks, and connected with (and worked
by) the link B, which is actuated as described in reference to the previous
Figures. The opposite ends of the cords X, X, are fixed to the needle
bar at points g', d².
Or the arrangement shown in Figure 9 may be adopted, in which the
reciprocating link D is connected with the bell crank f" at f", and thus
communicates reciprocating motion through link e to needle bar I.
Sometimes, as shewn in Figure 10, the link D may be made to draw
the duplex or jointed lever E, F, within the line of the needle bar as
far as it drives it without or beyond such line, as shown by dotted
lines E', F'. In this case it is desirable to connect the link with the
casting over the centre of the needle bar. When this arrangement is
adopted in lock-stitch apparatus a double ended or double pointed
shuttle should be used. In this modification two dips of the needle,
and thus two stitches will be made for cach revolution of the driving
shaft A or crank A'. We can make two stitches to one turn of the
crank pin or driving power by giving alternate rocking motion to pulley
F, Figure 8, by connecting it with the cords X, X, and by connecting
it also to needle bar I by a link attached to pulley F³ by a crank pin.
Figure 11 shews an arrangement in which a duplex compound or
jointed lever O, P, is used to drive the shuttle. This lever is connected
with the casting at O', and it is worked by the crank A' from driving
shaft A by means of link N.. One arm P of the lever is connected with
the sliding bar Q which carries the shuttle carrier.
In the arrangement shown in bottom plan, Figure 12, a duplex or
jointed lever R, S, is used to drive the feed bar T which is held in a

page_text: slide or other convenient appliance for ensuring rectilinear action. The
duplex lever R, S is connected with the feed bar at T and with the
casting at T'. It is operated by a link q* which connects it with the
rocking lever S, Figures 1 and 2.
Figures 13, 14, 15, 16, refer to arrangements for widening the
shuttle spools. Figure 13 is an elevation shewing the arrangement
applied to a crank pin on a vibrating centre. y is the worm wheel of
the spool gearing with a toothed wheel y* on a spindle or stud y³ on
the casting; y, y³, are crank pins on the wheel y; they work against
a guide wire y', bent at right angles, and its end is annular or tubular,
and vibrates on a centre or pin y³.
A1º is a
I proceed to describe the arrangements shewn in Fig. 14.
pulley carrying on one end of its spindle a worm wheel B1 which
receives the bobbin to be wound and drives a toothed wheel E1, which
carries two studs or crank pins E", E. These studs work alternately
against a wire guide C₁ kept in contact with them by a spring H". To
this wire guide a curve, as afterwards described, is given of the requisite
form to compensate for the imperfect motion of crank pin. The mode
in which the curve given to these guide wires y', C₁ is determined is
ascertainable by the diagram Figure 16, and the description referring
thereto given also in reference to the curve imparted to the sides of the
opening, Figure 15. At one end the guide wire C₁ carries a thread
guide eye at I¹. The guide has a reciprocating action in a rectilinear
direction by means of wires which slide through holes in the casting
at F, F, F13, F14.
In the arrangement Figure 15 the wheel E" carries one crank pin E¹³
only, which pin works in a lozenge-shaped opening A20 formed in a
plate A. Within this opening is placed a plate B2 of nearly the same
form as the opening; this plate oscillates on its centre at B", but it is
kept in the proper direction by a spring Co. As the crank pin E13
moves in the direction of the arrow between the edges of the plate D20
and the edges of the opening A⁰ it easily presses the central piece B⁰⁰
in one direction until it has passed the angle D20 or D³¹. The spring C²º
then restores the plate B20 to place, and the crank pin then travels along
the opposite side of the opening, that is to say, in the between
the opposite edges of the plate B and opening A20.
space
To find the correct form of the opening A2, Figure 15, or of the wire
guides y, C1, Figures 13, 14, 15, we proceed by the following rule

page_text: or formula illustrated in Figure 16-Divide the circumference of a
circle h*, Fig. 16, into a convenient number of equal parts, say, 16;
rule lines i, i, i, i, and j', j, j³, &c.; prolong one set of these lines in
one direction, and rule line across them at right angles; this line
at its extremities serves as a side of each space and which corre-
sponds with the passage of crank pin across arcs and l'of circle h;
now measure difference between line m and ; this difference being
measured off from line at points n and n mark points through
which curve of opening must pass. In like manner difference. between
13 and o must be used on lines p and p², remembering that they are
in addition to former space in measuring from line *, or in other
words, they must be measured from a point on line p as far from k as
n is from. The peculiar feature of this arrangement is that equal
motion of the slide is obtained by adding to the motion of crank pin
where required, but not by so forming curve as to take from or diminish
motion of the crank pin in any part of its path. Thus, for instance,
suppose in Figure 18 the circle h* to be 2 inches diameter, and to
represent the path of a crank pin describing a circle of that size, then
if worked with a guide having an opening of the form shewn it would
throw its guide into an equal reciprocating motion, whose stroke would
be 4 inches nearly.
Figure 17 is a plan of a table or stand on which the casting or frame
holding the working parts of the sewing machine is fixed, such casting
or frame has a dovetail base 2*, which fits over a corresponding dovetail
projection p formed on a table or stand, which is supported by three
wrought-iron legs connected together by a stay, each having a lip or
flange at top.
When, as in Figures 1, 2, 3, 4, to 12 inclusively, the needle bar,
shuttle bar, and feed bar are driven by connections operated by one and
the same crank or crank pin, the parts being arranged and combined and
operating as above described, then their suitable action in relation to the
action of each other is secured at accurate intervals.
Having now described the nature of the said Invention, and in what
manner the same may be performed, we declare that we claim,
First. The method of and arrangement for operating the needle bar by
an arm, link, cord, or other contrivance working longitudinally of the
arm of the casting or frame of the machine, and acting with an alternate
pulling and pushing motion, substantially as described.

page_text: Second. The mode of and arrangements for communicating motion to
the needle bar by means of levers and connecting rods or links, used with
or without bell cranks, and worked from the crank, crank pin, or driving
power, substantially as described, whereby the use of numerous cams or
excentrics is dispensed with.
Third. The application of the method of action and arrangement of
parts claimed in (and described in reference to) the second claim to the
operating of the shuttle, substantially as described.
Fourth. The application of the method of action and arrangement of
parts claimed in (and described in reference to) the second claim to the
operating of the feed bar, substantially as described.
Fifth. The arrangement and combination of parts herein-before
described, whereby relative action is imparted to the needle bar, the
shuttle bar, and the feed bar at accurate intervals by connections
operated by one and the same crank or crank pin as explained.
Sixth. The employment of a foot presser mounted concentrically with
the needle bar, substantially as and for the purpose described.
Seventh. The combination of fellers, hemmers, or other like append-
ages with a foot presser mounted as claimed in (and described in
reference to) the sixth claim, so that they will work in any direction
of feed, the needle being always in proper position with regard to the
hole in the foot presser for the passage of the needle.
Eighth. The arrangement and combination of parts and the method
of action for making or producing two stitches for each revolution of the
driving crank or driving shaft by drawing or moving the duplex com-
pound or jointed lever (or a connection therewith) within and without
the line of the needle bar, so that it shall travel to points equidistant of
the needle bar on each side thereof, substantially as described.
Ninth. The arrangement, combination of parts, and method of action
for making or producing two stitches for each revolution of the driving
crank or driving shaft by doubling the stroke of the link, as described in
reference to Figures 8, 9, and 10.
Tenth. The employment of a duplex compound or jointed lever
arranged and operating as described for actuating the needle bar.
Eleventh. The employment of a duplex compound or jointed lever
arranged and operating as described for actuating the feed bar.

page_text: Twelfth. The employment of a duplex compound or jointed lever
arranged and operating as described for actuating the shuttle.
Thirteenth. The arrangement and combination of parts and method
of action for converting rotary into reciprocating motion for the purpose
of winding thread or other fibrous material on the shuttle spools in
sewing machines, and for other purposes by the direct action of a crank
pin working in an opening with curved sides or against a curved edge,
guide wire, or guide, the curve being formed substantially as described
in reference to Figures 13, 14, 15, and 16, whereby the stroke of the
crank pin, where deficient, is compensated for, as above explained.
Fourteenth. The general arrangement and combination of parts of
sewing machines, substantially as described with reference to the accom-
panying Drawings.
In witness whereof, I, the said Robert Bagshaw Plum, for myself
and on behalf of the said Robert George, have hereunto set my
hand and seal, this First day of December, in the year of our
Lord One thousand eight hundred and sixty-nine.
Witness
M. HENRY,
68, Fleet Street,
Fleet Chambers, London.
R. B. PLUM. (L.S.)