IMROVEMENTS IN SEWING MACHINES
Year: 1875

page_text: LETTERS PATENT to Hunter Henry Murdoch, of No. 7, Staple Inn,
in the County of Middlesex, Patent Agent, for the Invention of
"IMROVEMENTS IN SEWING MACHINES."-A communication from abroad
by Joseph Leonard Follett, of New York City, in the United
States of America.
Sealed the 1st June 1875, and dated the 14th April 1875.
COMPLETE SPECIFICATION filed by the said Hunter Henry Murdoch
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 14th April 1875, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HUNTER
HENRY MURDOCH, of No 7, Staple Inn, in the County of Middlesex,
Patent Agent, send greeting
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN SEWING MACHINES," and have petitioned Her Majesty to grant unto
mc, my executors, administrators, and assigns, Her Royal Letters
Patent for the same, and have made solemn Declaration that the same has

page_text: been communicated to me from abroad by Joseph Leonard Follett, of
New York City, in the United States of America, and that the same is
not in use by any other person or persons, to the best of my knowledge
and belief.
NOW KNOW YE, that I, the said Hunter Henry Murdoch, do hereby
declare that the following Complete Specification, under my hand and
scal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement thereof, that is to say :-
These improvements have primarily for their object the production of
a revolving hook sewing machine capable of sewing in either direction
at pleasure. Some of the said improvements however are applicable to
sewing machines generally.
The nature of my said improvements can best be understood by
describing in detail and succession the structure of the various parts
of the machine, referring at the same time to the accompanying
Drawings.
The revolving hook is shown in side elevation in Figure 1, and in
transverse central section and front clevation in Figure 4.
The hook A is a double hook with two points a, b. Each point is the
counterpart of the other, and cach half of the double hook is a counter-
part of the other. Leading from each hook is a peripheral groove c,
which decreases in depth, and at last vanishes as it reaches the central
cast-off d, which is common to both hooks. This groove conducts onc
of the throads of the loop to the said cast-off. The other thread of the
loop passes over the lateral surface e on the hook, and is thrown off to
pass between the bobbin case and the hook. The portion of the hook
where the cast-off is located projects laterally far enough to extend
beyond that face of the bobbin case contiguous to the hook, as seen in
Figure 1, where B represents the said bobbin case. The consequence is
that that thread which is conducted to the cast-off by the groove c is
thrown off from the hook over or on the outside of the bobbin case, so
that the bobbin case will in effect pass through the loop carried around by
the hook a or b The hook takes the thread from the needle on the sido
opposite to the bobbin
The double hook is fixed to and rotates with the driving shaft C of
the machine. It may have a spindle C' projecting from its rear face to

page_text: fit in a socket in the front end of the driving shaft, where it will be
hold by a set screw ƒ (Figure 1). In this way provision is made for the
adjustment of the hook with relation to the needle, if this should at any
time be found necessary.
The bobbin casc is shown at B in side elevation, Figure 1, and in
front clevation and transverse central section, Figure 5. On the face
next to the revolving hook it has a central rounded projection g, forming
a bearing to fit in a corresponding central recess g¹ in the face of the
revolving hook In the outer face of the bobbin casc is formed tho
central recess, in which is inserted the bobbin D The projection g
is not absolutely necessary, and can be dispensed with if desired.
The bobbin may be pierced axially to receive a central pin ½ pro-
jecting from the bottom of the case, on which pin it will revolve, but
this pin is not a necessity.
On the bobbin case is a tension consisting in this instance of a spring
strip 2, which bears against the face of the case with a yielding pressure.
At one point in the side of the bobbin case surrounding the bobbin
recess is a thread slot j, which extends under the tension i in the tension
strip, to one side of the thread slot, is also a slot k. The thread from
the bobbin is drawn through the thread, passes thence under the spring
tension 2, and then out through the slot k. The thread between, and is
thus held by spring pressure, the degree of which pressure is regulated by
suitable means, as, for instance, by an adjusting screw (, passing through
the bobbin case from rear to front with its outer end resting against the
rear face of the spring tension strip.
When the machine is in operation under the arrangement just
described the bobbin case remains stationary, the bobbin revolves as the
thread is drawn from it, and the bobbin thread is always of the same
length, or nearly so, this distance being about that which intervenes
between the tension slot % and the point where the stitch is made in the
cloth or material that is being sewn.
The bobbin case is held in place by an adjustable holder E, an annular
plate with a stem and foot, by which it is secured to the under side of
the cloth plate, the foot having formed in it a slot through which passes
a set screw m into the cloth plate E³. The portion of the cloth plate to
which the bobbin holder is attached can be made to slide in and out, so

page_text: that by withdrawing the plate the holder will be removed from the
bobbin case, and the latter will be permitted to drop The holder E
serves also to hold the bobbin in the bobbin case The bulging part
of the bobbin fits in the central opening in the bracket, as seen in
Figure 1.
By the described arrangement of the bobbin and bobbin case under
the table I am enabled to bring the cloth plate of the machine down
flush with the surface of the table.
•
With the mechanism above described there is required a reversible feed
that will be operative in either direction. This I secure in the following
way, referring to Figures 1 and 2 -The feed proper consists of feed
surfaces n, n, formed on the extremitics of arms o, which project from a
spring strip p bent into a circular or nearly circular form, having its
ends, which terminate in said feet carrying arms o, held together by
adjusting screw o', by which the said arms are brought nearer together
or further apart, as occasion requires. The spring strip p is pivotted at
' to the rear face of the disc r, which is mounted loosely on an excen-
tric s on the driving shaft C or the spindle C. The disc is prevented
from rotating with the excentric by a pin on its rear face, which projects
into a vertical slot in the U shaped bracket plate fixed to the under
side of the cloth plate. By this means the disc will have imparted to
it by the excentric an up-and-down and to-and-fro movement. The
feed surfaces being attached to this disc by a pivot pin will partake
of this up-and-down movement; they obtain their to-and-fro movement
from the same source by a pin or stud on the disc that projects and
plays between the arms o, and the extent of this movement of the feed
which determines the length of stitch will be in accord with the distance
between these arms, which is regulated by the adjusting screw o'. The
teeth of the feed surfaces are turned some in one direction, others in tho
other direction, so that they will take hold of the cloth whichever way
they move. The feed is thus reversible, and will operate equally well in
either direction.
I prefer to use the feed mechanism herein-before described, but it
will be understood that its construction may be varied to a considerable
extent, so long as the feed remains reversible and operative in either
direction.
It has been my object in this machine to take up the slack, and to
complete each lock stitch separately after the needle leaves the cloth,

page_text: and before it enters it again, while preserving a regular and uniform
movement of the needle bar, that is to say, a movement which is equal
and of uniform speed throughout the stroke. Ieretofore, so far as I am
informed, in lock-stitch machines, where there is this uniform movement,
the taking up of the slack and the completion of each stitch separately,
as above specified, has not been effected during the time the needle is
out of the cloth, or where in the said machines the specified result has
been attained, the movement of the needle bar has not the uniformity
and regularity which I propose to attain, but it has been effected by
means of a cam, which will slow or check the speed at stated times, in
order to allow the take-up time to complete its action before the needle

page_text: which it is held by a set screw entering a peripheral groove in said pin, as
indicated in dotted lines in Figure 1. The outer end or head of the
pin 6 carries a stud or journal 7, on which is hung the upper end of the
connecting rod I.
The take-up, shown in Figure 1, consists of an elbow lever F, having in
its front end a hole or its equivalent for the passage of the upper thread,
which runs from the spool 8 through the tension 9 to the take-up. The
lever F vibrates on pivot 10, and at its lower end it bears against a
cam 11 on the side of the driving and balance wheel 12 The lever is
pressed against the cam by a spring.
The pin
A modification of the take-up is shown in Figure 6, which is a side
clevation partly in section In this modification the needle bar lever II
serves to actuate the take-up, which consists of an arm K hung on a
pivot on the head of the machine, and controlled by a spring which-holds-
it normally in a position nearly horizontal, or with its front end slightly
clevated. The end of the arm in the rear of the pivot is bevelled on its
upper side side, as shown This end of the arm is operated on by a pin II¹
laterally projecting from the needle bar lever, the pin being a steel pin
carrying a roller sleeve covered with raw hide. When the needle bar
lever is in its uppermost position the pin II' is raised above and out of
contact with the take-up On the down stroke the lever drops about %
of an inch before the pin begins to act on the take-up, this interval
being to allow the cast-off to clear the thread from the hook
then commences to press on the take-up, which by this action has its
front end gradually raised, so as to take up all slack before or by the
time the needle reaches the cloth. By this time the pin will clear the
take-up, which being thus released will drop as far as necessary to supply
all the thread required for the remainder of the stroke, which will be
about of an inch. Thus the take-up when not positively operated on
by the working parts of the machine will yield to the influence of the
thread, and will answer to the demands made by the thread in the various
movements. The lever II on the up stroke passes by and above the
take-up, and in so doing the pin II' will by its action on the rear end of
the take-up throw the take-up down, which down movement occurs
when slack is required for the loop, and is of sufficient extent to allow
all needed slack for this purpose.
I provide for adjusting the stroke by lengthening or shortening at
pleasure the connecting rod between the driving excentric or crank and

page_text: the needle bar lever. This is effected by screwing the lower end of the
connecting rod I in a socket L. By pulling out the pivot pin 7 that con-
nects the rod I with the needle bar lever the rod can be screwed in or
out of its socket, which will have the effect of correspondingly shortening
or lengthening its working length.
The driving and balance wheel may be provided with two peri-
pheral belt grooves, as shown at M, M', Figure 6, of different diameters,
the larger when slow motion is required, the smaller when fast motion is
required.
The packing box I use is shown in section at N, Figure 6. It is of
thimble formation with a milled head and screw-threaded exterior, which
screws into a socket in the under side of the head around the needle bar.
In using this device I wind a little wicking, or any other suitable packing,
around the needle bar, then push the box up against the packing
to the under side of the head, and then screw the box into its socket.
The further it enters the socket the more tightly the packing or wick is
compressed around the needle bar, any amount of oil may be put on the
bar above the packing, and the bearing may become worn, but the oil
can never pass the packing, or get to the needle or the work. The
packing can be further compressed at any time desired by simply
screwing in further the packing box This device also furnishes an
additional bearing for the needle bar, and prevents all rattling. If one
side of the bearing should become worn a half or quaiter turn of the
box will present a new bearing surface, and will take up all play or
looseness.
As seen in Figures 1 and 6 I extend the head of the machine on the
presser foot side down near to the bed or cloth plate of the machine, and
in this downward extension O I form the bearing of the presser foot. By
thus bringing the bearings of the presser foot or bar near to the bed plate
I make the bar steady and firm, and obviate its tendency to spring.
This extension of the head is also of advantage, as furnishing a con-
venient point for the attachment and adjustment of additional machinery
or attachments used from time to time with the machine, it further
serves to protect the work.
I cover the rear and sides of the standard of the goose neck with a
case P, Figures 1 and 6, which at its base and rear is forked and
arched, as shown in Figure 5, to accommodate the hand balance,

page_text: duving, and cam wheel, and is hinged at y, y, to the machine. With
this case no screw or catch is needed to hold it in place, and it can
be thrown back to uncover the machinery whenever desired.
This arrangement of the case is that which, for many reasons, I prefer.
But the same may be modified in various ways, all that I really require
being that the standard and the moving parts in proximity thereto
should be covered by a case hinged in such manner that it can bo
turned back to expose the said parts when required.
Having now described this Invention, as communicated to me, and
the manner in which the same is or may be carried into effect, what I
claim and desire to secure by Letters Patent arc, –
-
First. The reversible_rotatory double hook, constructed and operated
as herein shown and described.
Secondly. In a rotatory hook lock-stitch sewing machine the com-
bination with the rotatory hook of a stationary bobbin casc supported:
against the hook a bobbin carried by and revolving within the said
case, and a tension for the bobbin thread, substantially as shown and
described.
Thirdly. The reversible rotatory double hook in combination with
the revolving bobbin, stationary bobbin case supported against the said
hook, and bobbin thread tension carried by the said case for joint opera-
tion, as shown and set forth.
Fourthly. The reversible rotatory double look, revolving bobbin,
stationary bobbin case, and bobbin thread tension in combination with
a needle, which on its down stroke cuters between the stationary:
bobbin case and the rotating hook for joint operation, as shown and sct
forth.
Fifthly In combination with the elements specified in the preceding
clause a reversible feed, substantially as shown and described
Sixthly. A reversible draw feed carried by and deriving its movements
from a disc or plate mounted on and operated by a rotating excentric,
from which it derives an up-and-down and to-and-fro movement, sub-
stantially in the manner shown and set forth.
Seventhly. In combination with the feed carrying disc or plate and
excentic for operating the same the feed proper pivotted to the said

page_text: disc, so as to follow its up-and-down movement, and receiving between
arms adjustable nearer to or further from one another a pin or stud,
which is attached to the said disc, and imparts to the feed proper a to-
and-fro movement, substantially as set forth.
Eighth. In a lock stitch machine the combination with the
mechanism for delivering and working the under thread, of a needlo
bar having a reciprocating movement of regular and uniform speed, and
a take-up arranged and operating together in the manner shown and
described, whereby, while a regular motion and uniform rate of speed of
the needle is preserved, the slack is taken up, and each stitch separately
is completed after the needle leaves the cloth, and before it cntors it
again.
Ninthly. A take-up operated intermittently by the needle bar lover or
other working part of the machine at the times specified, and free when
not so operated to yield to the draught of the upper thread, substantially
as shown and set forth.
Tenthly. The combination in a lock-stitch machine of a rotatory
hook and a straight needle having regular and uniform movement, as
described, with a take-up arranged and operating as described to take up
the slack of one stitch before the next stitch is commenced, substantially
as and for the purposes set forth.
Eleventhly. The vibratory takc-up and its spring in combination with
the needle bar lever arranged to operate the said take-up at the times
and in the manner substantially as shown and described.
Twelfth. The combination with the bobbin case of the bobbin holder
fixed to and adjustable on the under side of the cloth plate, substantially
as and for the purposes set forth.
Thirteenthly. In combination with the bobbin case the bracket holder
for the same, and the removable cloth plate section carrying the said
holder, substantially as shown and set forth
Fourteenthly The removeable cloth plate section in combination with
the bobbin case holder attached to and adjustable on the said section, as
and for the purposes shown and set forth.
Fifteenthily. The cover or case encasing the sides and back of the
standard and its appurtenances and hinged to the machine, substantially
as shown and set forth.

page_text: Sixteenthly. In combination with the needle bar lever and its
driving crank or excentric the intermediate connecting rod adjustable
in length, substantially as and for the purposes shown and set
forth.
Seventeenthly The packing box, constructed and applied substantially
as shown and described.
Eighteenthly. The sewing machine head formed on the presser foot
side with a downward projection for the bearings of the presser bar, sub-
stantially as shown and set forth.
In witness whereof, I, the said Hunter Henry Murdoch, have here-
unto set my hand and scal, this Fourteenth day of April, in the
year of our Lord One thousand eight hundred and seventy-
five.
Witness,
B. WILCOX,
his Clerk.
H. H. MURDOCHI. (L.S.)