IMPROVEMENTS IN LAING'S OVERHEAD SEWING MACHINE
Year: 1878

page_text: LETTERS PATENT to William Lee, Engineer, of Laing's Patent Overhead Hand-
stitch Sewing Machine Company, Limited, of Dundee, in the County of Forfar,
North Britain, for the Invention of "IMPROVEMENTS IN LAING'S OVERHEAD
SEWING MACHINE."
Sealed the 3rd May 1878, and dated the 14th February 1878.
PROVISIONAL SPECIFICATION left by the said William Lee at the Office of
the Commissioners of Patents on the 14th February 1878.
"
WILLIAM LEE, Engineer, of Laing's Patent Overhead Hand-stitch Sewing
Machine Company, Limited, of Dundee, in the County of Forfar, North Britain.
IMPROVEMENTS IN LAING'S OVERHEAD SEWING MACHINE."
This Invention has for its object to simplify and otherwise improve the construc-
tion and action of what is known as Laing's overhead sewing machine, and is
described in the Specification of Letters Patent granted to James Laing, and dated
12 October 1874 (No. 3493).
The present improvements relate to details connected with the part of the machine
known as the thread barrel, and which, forming a characteristic and essential
feature of the machine, rotates and moves longitudinally, partly within the spiral
or helical needle, and carrying coiled upon it the untightened portion of the thread
or twine, assists it through the cloth or fabric, and insures its being uniformly and
properly tightened.
The longitudinal movement of the thread barrel, on the proper relation of which
movement to the others, and to the peculiarities of the materials that are being
operated on in each case, the satisfactory action of the machine largely depends, has
hitherto been derived in a comparatively direct way from the main driving details
of the machine, its rate being dependent on parts which have to be adjusted by
hand. By the present Invention, however, this longitudinal movement is derived
directly from the thread barrel itself, and in a manner depending on the tension of
the thread or twine, so that it is automatic.

page_text: In carrying out the Invention according to one modification, the outer end of
the thread barrel which is hollow is made compressible, being by preference divided
by numerous slits which are slightly inclined or nearly longitudinal, the strips of
metal thus formed being bended inwards at the end. Within the compressible part
of the barrel there is a pulley carried by a spindle, having a forked or tubular part
extending backwards; and at or near the back end of the forked or tubular part
there are provided a couple of movable engaging bits formed with segments of
internal screw threads capable of engaging with a fixed central screw spindle. The
pulley inside the compressible end of the thread barrel can be adjusted by means of
a screw nearer to or further from the end of the barrel, and it may if necessary be
coated with leather or other suitable frictional surface material. As the sewing
action of the machine proceeds, the coils of thread or twine gradually tighten upon
the compressible end of the barrel and make it grip the pulley inside of it. This
causes the rotation of the barrel to be imparted to the pulley, which turning the
tubular or forked piece carrying it, makes the screwed bits at the back act on the
fixed screw spindle so as to move the barrel backwards in the manner required for
casting off the coils from its end. When the barrel has been moved fully back, the
internally screwed engaging bits will have screwed themselves off the screwed part
of the spindle, and whilst the barrel is being returned forward again, they are kept
out of gear from the screwed spindle.
The arrangement may be modified by making the central screwed spindle the
piece which carries the pulley inside the thread barrel, and causing it to work
through internally screwed bits which are stationary, whilst the barrel moves back-
wards, and are opened to allow of its free return forwards. Or the return forwards
may be effected by giving a rapid motion to a nut through which the spindle works,
or to the spindle when the latter does not move longitudinally.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Lee in the Great Seal Patent Office on the 12th August
1878.
WILLIAM LEE, Engineer, of Laing's Patent Overhead Hand-stitch Sewing
Machine Company, Limited, of Dundee, in the County of Forfar, North Britain.
IMPROVEMENTS IN LAING'S OVERHEAD SEWING MACHINES."
My said Invention has for its object to simplify and otherwise improve the con-
struction and action of overhead sewing machines of the kind known as Laing's,
and one modification of which is described in the Specification of Letters Patent
granted to James Laing, and dated 12 October 1874 (No. 3493).
My present improvements relate to details connected with the part of such
machines which is known as the thread barrel, and forms a characteristic and
essential feature of Laing's machines, distinguishing it from all previous attempts to
obtain mechanically what is known as the overhead, or over edge, or overcast
stitch. This thread barrel is an essential part, not only of the original modification
of Laing's machines described in the Specification herein-before referred to, but also of
other modifications of Laing's machines, such as the one described in the Specification
of Letters Patent granted to William Webster, and dated 30 November 1875 (No.
4146), or the one described in the Specification of Letters Patent granted to William
Martin, David Russell Dawson, and Robert Orchar, and dated 6 May 1876 (No.
1909); or the one described in the Specification of Letters Patent granted to Robert
McLaren Young, and dated 1 June 1876 (No. 2317).
My present Invention is applicable to any of the modifications of Laing's
machines herein-before referred to. I will however first describe it as adapted for
the original modification, in which the thread barrel rotates and moves longitudinally
partly within a spiral or helical needle, and carries coiled upon it the untightened
portion of the thread or twine, assisting it through the cloth or fabric, and
insuring its being uniformly and properly tightened.
The longitudinal movement of the thread barrel relatively to the needle, on the
proper relation of which movement to the others and to the peculiarities of the
materials that are being operated on in each case the satisfactory action of the
machine largely depends, has hitherto been derived in a comparatively direct way
from the main driving details of the machine, its rate being dependent on parts
which have to be adjusted by hand; by my present Invention however this
relative longitudinal movement is derived directly from the thread barrel itself,
and in a manner depending on the tension of the thread or twine, so that it is
automatic.
In carrying out my Invention according to one modification the outer end of the
thread barrel which is hollow is made compressible, being by preference divided
by numerous slits which are slightly inclined or nearly longitudinal, the strips of
metal thus formed being bended inwards or rounded at the end. Within the
compressible part of the barrel there is a pulley carried by a spindle having a forked
or tubular part extending backwards, and at or near the back end of the forked or
tubulár part there are provided a couple of movable engaging bits formed with
segments of internal screw threads capable of engaging with a fixed central screw
spindle. The pulley inside of the compressible end of the thread barrel can be
adjusted by means of a screw nearer to or further from the end of the barrel, and it
may be if necessary be coated with leather or other suitable frictional surface
material. As the sewing action of the machine proceeds the coils of thread or
twine gradually tighten upon the compressible end of the barrel and make it grip
the pulley inside of it. This causes the rotation of the barrel to be imparted to the
pulley, which turning the tubular or forked piece carrying it makes the screwed bits
at the back act on the fixed screw spindle, so as to move the barrel backwards in the
manner required for casting off the coils from its end. When the barrel has been
"

page_text: moved fully back the internally screwed engaging bits will have screwed themselves
off the screwed part of the spindle, and whilst the barrel is being returned forward
again they are kept out of gear from the screwed spindle.
In a second modification the pulley inside of the compressible end of the barrel is
carried on a central screwed spindle, and this spindle works through one or more
internally screwed bits, which are stationary whilst the barrel moves back wards,
and are opened to allow of its free return forwards; or the return forwards may
be effected by giving a rapid motion to a nut through which the screwed spindle
works, or to the spindle when the latter does not move longitudinally.
And in order that my said Invention and the manner of performing the same may
be properly understood, I hereunto append a Sheet of explanatory Drawings to be
herein-after referred to, and representing a modification of the Laing thread barrel
as made or fitted with my improvements. In these Drawings the same reference
numerals are used to mark they same parts wherever they are repeated.
Figure 1 on the accompanying Sheet of Drawings is a plan, and Figure 2 is a
longitudinal vertical section, whilst Figure 3 is a face view of the pulley 4, which
is inside of the compressible end 5 of the barrel 6. The barrel 6 is represented as
drawn back within the tube or cylinder 7 which carries it, and which is shown as
partly broken away in Figure 1.
The outer end 5 of the barrel is formed of a piece of thin wrought iron or steel,
or other suitable metal fixed on the body 6; and this end 5 is made compressible
by being slit, as shown, the ends of the strips formed by the nearly longitudinal
slits being rounded to prevent the thread or twine from catching on them.
The pulley 4 is represented as having a circumferential covering, which may be
of rubber, or leather, or other suitable frictional material, The pulley is fitted on a
tube 9, which is fixed to the outer end of a spindle 10, the after part of which is
screwed.
The tube 9 has in it a longitudinal slot, in which there works a part connecting
the pulley 4 with a central internally screwed boss or nut 11, and through this nut
11 there passes a small screw spindle 12, held in the tube 9, and fitted with a
button 13 at its outer end for turning it by. By means of this button 13 the
pulley 4 can be adjusted outwards or inwards to suit the tension required, the more
outward positions giving lesser tensions, as less tension is required to compress the
more outward parts of the metal strips forming the end 5 of the barrel so as to
grip the pulley.
The after screwed part of the spindle 10 engages with a bit or small block 14,
which is formed with segments of internal screw threads, and which is held in a
guide 15 fixed to the bracket 16 which carries the back end of the cylinder 7. A
rod 17 attached to the bit or block 14 serves for raising it when required to allow
the barrel 6 to move forward, this rod being acted on by a bell crank 18 and rod
19, whilst a spring 20 insures the bit 14 engaging with the screwed spindle when
let down.
The screwed spindle 10 has a cross head 21 held loosely on its back end, and to
this cross head are attached cords 22, which pass over pulleys 23 to a weight, by the
action of which the screwed spindle 10, and with it the barrel 6 are moved forward
whenever the screwed bit or block 14 is lifted.
The cross head 21 is prevented from turning with the spindle 10 by a projection
24 on it working on a fixed guide rod 25. The extent of the forward movement
has to be made to suit the length of seam to be sewn, and is determined by
suitably adjusting a pair of nuts 26 on the spindle 10.
The rotation of the barrel 6, 5, may be effected in the same manner as in the
original modification of Laing's machine, or in any other convenient manner, my
present Invention not having to do with the mode of driving the barrel.
Instead of the pulley 4 being adjustable on the spindle 10 it may be fixed on that
spindle, the tension of the thread or twine being in that case dependent on the drag t
applied to the other end of the spindle.
In the modification of Laing's machines described in the second Specification

page_text: herein-before referred to, the relative longitudinal movement required between the
needle and the thread barrel is obtained by giving a longitudinal movement to the
needle carrier, the thread barrel rotating but not moving longitudinally relatively
to the framing, this being an obviously equivalent arrangement and yielding an
identical result with a mere transposition of the actions of the parts between which
the relative movement is required.
In applying my Invention to this modification the screw spindle 10 being arranged
to have no longitudinal movement, will, by its action on the bit or block 14, or on
an internally screwed nut, cause that bit or nut to move longitudinally and impart
the required movement to the needle carrier. Or the thread barrel may be arranged
to move longitudinally, and the needle carrier to have no longitudinal movement,
the other parts remaining as in Webster's modification, in which case my improve-
ment can be applied in the same way as in the original modification.
In the modification of Laing's machines, described in the third Specification
herein-before referred to, the relations and movements of the thread barrel and
needle are the same as in the original modification, and the application of my
improvements thereto is therefore also the same.
In the modification of Laing's machines described in the fourth Specification
herein-before referred to there are two thread barrels, and they have no longitudinal
movement relatively to the needle, whilst the direction of feed is reversed as com-
pared with that in the original modification. The two barrels, however, act as one,
and the direction of feed can be made the same as in the original modification, and
in that case my improved modification of Laing's thread barrel may be advanta-
geously used, requiring little or no change from what is herein-before described to
adapt it for such use.
Having thus particularly described my said Invention, and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original, and claim as the Invention secured to me by and in terms of the herein-
before in part recited Letters Patent is, the application and use in any modification
of Laing's overhead sewing machine of a thread barrel, the end of which being com-
pressible by the tension of the thread or twine is arranged to grip an internal
pulley and cause such pulley, by means of a screw, to effect a relative longitudinal
movement between the thread barrel and the needle, substantially as and for the
purposes herein-before described.
In witness whereof, I, the said William Lee, have hereunto set my hand
and seal, this Tenth day of August, in the year of our Lord One thousand
eight hundred and seventy-eight.
WILLIAM LEE. (L.S.)