Improvements in Overedge Sewing Machines.
Year: 1888

page_text: Date of Application, 7th Mar., 1888
Complete Specification Left, 18th July, 1888
Complete Specification Accepted, 24th Aug.. 188:
PROVISIONAL SPECIFICATION.
Improvements in Overedge Sewing Machines.
I, DAVID RUSSELL DAWSON, of 57 Meadowside, Dundee, in the County of Forfar,
North Britain, Merchant, do hereby declare the nature of this Invention to be as
follows, that is to say :-
My said Invention has for its object to improve and simplify the construction of
parts of and in connection with the thread barrel of sewing machines making an
overedge stitch and having the thread or yarn first laid round a barrel in loops which
are allowed to pass off the end of the barrel in a manner to give a proper tension to
the stitches as they are being successively tightened.
In carrying out my Invention according to one modification I construct the end of
the barrel of a stepped form, that is to say, with short portions of reduced diameters.
The shoulders are rounded and the successive smaller parts are by preference
successively narrower or of less extent in the direction of the length of the barrel.
I believe two such steps will work satisfactorily but there may be a single step or
more than two. The stepped end may be in the same piece with the barrel or it may
be in a separate piece fixed to the barrel and either of metal or wood or other suitable
material. A plate fixed on the inner end of a rod is pressed in any convenient way
against the barrel end; and as each loop of thread or yarn approaches the end of the
barrel it slips off the largest part on to the first step and then on to the second and
finally passes between the extreme end and the pressing plate. The thread or yarn
has an action tending to move the barrel back, and its tension when tightening the
stitches is in part due to this backward movement of the barrel and in part to the
resistance opposed to its slipping off the end of the barrel.
According to a second modification I combine what is described as the first
modification with a button or small curved disk fitted in the extreme end of the barrel
and pressed outwards by a spring which spring allows the button to yield inwards
when a loop passes between it and the pressing plate. The pressing plate may be
shaped to fit closely upon the button or end of the barrel and with a groove to guide
the thread or yarn when entering between the plate and barrel end.

page_text: In combination with either the first or second modification there may be fitted in
connection with the pressing plate or bar carrying it one or more ratchet catches or
equivalent devices to prevent the plate from being pressed outwards when the thread
or yarn passes between it and the barrel end.
Dated this Sirth day of March 1888
EDMUND HUNT.
Applicant's Agent.
COMPLETE SPECIFICATION.
Improvements in Overedge Sewing Machines.
I, DAVID RUSSELL DAWSON, of 57 Meadowside, Dundee, in the County of Forfar,
North Britain, Merchant, 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, that is to say :-
My said Invention has for its object to improve and simplify the construction of
parts of and in connection with the thread barrel of sewing machines making an
overedge stitch, and having the thread or yarn first laid round a barrel in loops which
are allowed to pass off the end of the barrel in a manner to give a proper tension to
the stitches as they are being successively tightened. In overedge sewing machines
of the kind referred to the needle, which is of a helical form or in the form of a
circular arc, passes completely through the sacking or other material which is being
sewn and also round the thread barrel, laying a loop of the thread or yarn round the
barrel at each circuit. In sewing a seam, during the first part of the operation, the
thread is laid round the barrel without the stitches being tightened in the material;
but when almost all the thread has been thus laid in loops on the barrel, the end of
the thread being fixed in the material, which is being moved along either continuously
or step by step, the loops successively pass off the end of the barrel and the stitches
become successively tightened in the material. The tension or tightness of the stitches
depends upon the manner in which the loops pass off the end of the barrel, and it is
this part of the sewing operation which the improved mechanism hereinafter
particularly described is designed to effect in a better manner than heretofore.
On an accompanying sheet of explanatory drawings the improved parts are shown
together with a few other parts of the machine. Figure, 1, is a plan, figure, 2, is a
transverse vertical section, and figure, 3, is a sectional front elevation; whilst figure, 4,
is an end elevation of the barrel. In these drawings the same reference letters are
used to mark the same or like parts wherever they are repeated.

page_text: In carrying out the Invention according to one modification the end, A, of the
barrel, B, is constructed of a stepped form, that is to say, with short portions, C, D,
of reduced diameters. The shoulders are rounded and the successive smaller
parts, C, D, are by preference successively narrower or of less extent in the direction
of the length of the barrel. Two such steps, C, D, work satisfactorily but there may
be a single step, or more than two. The stepped end, A, may be in the same piece
with the barrel, B, or it may be, as shown, in a separate piece fixed to the barrel, and
either of metal or wood, or other suitable material, preference being given to a
material which does not become rapidly polished by the friction of the thread.
A plate, E, fixed on the inner end of a rod or movable bracket, F, which is guided
upon a fixed bar, G, is pressed against the barrel end, A; and as each loop of thread
or yarn approaches the end of the barrel it slips off the largest part on to the first
step, C, and then on to the second step, D, and finally passes between the extreme
end and the pressing plate, E. The thread or yarn has an action tending to move
the barrel, B, back or towards the left hand; and its tension when tightening the
stitches is in part due to this backward movement of the barrel, and in part to the
resistance opposed to its slipping off the end of the barrel by the pressing plate, E.
The barrel end, A, may be made entirely solid or without any movable part, and it
acts satisfactorily if made so, for some sizes of machine and kinds of sewing.
According to a second modification, however, and which is shown in the accom
panying drawings, I combine what is hereinbefore described as the first modification
with a button or sinall curved disk, H, fitted in the extreme end of the barrel end, A,
and pressed outwards by a spring, J, which spring allows the button to yield inwards
when a loop passes between it and the pressing plate, E. A screw, K, entered from
the inner end and screwed into a nut embedded in the button, H, retains the button
in position, and the button is made to rotate with the barrel by projecting parts
formed on its inner end as indicated by dotted lines in figure, 4, working in grooves
in the socket in the barrel end, A. The pressing plate, E, is by preference made as
shown, with its central part shaped to fit the front of the button, H, and with a step-
like depression round the middle part, such depression forming an annular groove
which guides and controls the thread or yarn when entering between the plate and
the barrel end.
In combination with either the first or second modification there may be, and is by
preference, fitted in connection with the pressing plate, E, or bar, F, carrying it, one
or more ratchet catches or equivalent devices to prevent the plate from being pressed
outwards, or towards the right hand, when the thread or yarn passes between it and
the barrel end, A. The pressing plate, E, is moved towards the left hand by means
of a cord, L, which passes round a pulley, M, and thence over a guide pulley, N, to
a weight (not shown). The pulley, M, is fixed on a spindle having also fixed on it
a fine-toothed ratchet wheel, P, with which there engages a pawl, Q, centered on a
fixed bracket. This ratchet wheel with its pawl allows the weighted cord, L, to move
the pressing plate, E, towards the left hand so as to follow the barrel, A B, and
maintain against the end thereof a suitable pressure which may be varied by altering
the weight attached to the cord, L; but prevents any return movement towards the
right hand. When at the beginning of a fresh seam the barrel, A B, and pressing
plate, E, have to be moved towards the right hand, the pawl, Q, is turned out of gear,
it being made with an upwardly extending horn which the attendant worker can
conveniently manipulate.
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-The improved combination of parts herein before described and shown in the
accompanying drawings.
2-In overedge sewing machines of the kinds hereinbefore indicated, making
the thread barrel with a stepped end substantially as and for the purposes hereinbefore
described.

page_text: 3-In overedge sewing machines of the kinds hereinbefore indicated making the
thread barrel with a stepped end, and with a spring end button, substantially as and
for the purposes herein before described.
4-In overedge sewing machines of the kinds herein before indicated combining a
thread barrel having a stepped end and with or without a spring end button, with
a pressing plate, shaped, arranged, and actuated substantially as hereinbefore
described.
Dated this Sixteenth day of July 1888
EDMUND HUNT,
Applicant's Agent.