IMPROVEMENTS IN SEWING MACHINES PART OR PARTS OF WHICH ARE APPLICABLE FOR OTHER PURPOSES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by James McHardy at the Office of
the Commissioners of Patents on the 13th June 1883.
"
JAMES MCHARDY of Dollar in the County of Clackmannan, North Britain
IMPROVEMENTS IN SEWING MACHINES PART OR PARTS OF WHICH ARE APPLICABLE
FOR OTHER PURPOSES
37
This Invention relates to Improvements in Sewing Machines, part or parts of
which are applicable for other purposes and it consists in the first place in
mechanism for enabling the bobbins or spools of sewing machines when empty to
be rewound or refilled with thread without the necessity of removing the said
spools or bobbins from the shuttles.
This object is effected by causing the bobbins to rotate within the shuttles or
the shuttles to rotate around the bobbins-For this purpose the spools or bobbins
may be made with a long journal or bearing projecting through one end of the
shuttle and so shaped that the bearing can be coupled to a rapidly rotating shaft
whereby the bobbin is revolved whilst the shuttle remains stationary or vice versa,
the bobbin may be held stationary by a fixed coupling, whilst the shuttle is
rotated by any suitable rotatory gearing.-In either case the thread to be wound
on the bobbin may be guided by a finger or traveller or by the mechanism herein-
after described to ensure its being evenly laid thereon, and in order to wind the
thread on the bobbins of existing shuttles which do not admit of one of the
bearings of the bobbin or spool passing through the end of the shuttle, the bobbin
is in such case rotated within the shuttle by frictional gearing.
Another improvement in the construction of the shuttle consiste in dispensing
with the ordinary drag holes which pass through the walls of the shuttle and
substituting therefor a slot which may be at either side of the shuttle and of a
quadrantal form, the thread being led from the slot to and through one or more
drag holes distinguished from those ordinarily in use by not passing through the
walls of the shuttle but passing through holes which are confined to the exterior
of the shuttle.
Another part of this Invention consists in substituting for the ordinary driving
wheel of the machine, a spring attachment for storing power by means of which
the said machine is driven and which is, or may be arranged to run for any
D...931

page_text: known length of time. This spring attachment is supported upon a shaft carried
and rotating in bearings situated at the lower part of the framing on which the
machine is carried and consists of a cylinder through which the aforesaid shaft
passes and upon which the cylinder is carried loosely in any suitable manner.-To
the interior of this cylinder one end of a spiral or other equivalent spring is
attached, the other end being attached to the shaft.-Around the outside of the
cylinder there is provided the mechanism for operating it which may consist of a
treadle and clutch device of any suitable construction or it may be so formed as to
allow of the said cylinder being rotated or wound up to any number of revolutions
by hand or by any other equivalent means, such for example as clockwork.-
Upon the aforesaid shaft there is carried a sprocket" wheel or its equivalent
and around this wheel a chain or band is carried, this band being passed at its
upper part around the driving pulley of the machine or around an intermediate
pulley for transmitting the motion to the said machine.-For equalizing the speed
of the cylinder after having been wound up, and released, a
« fusee or equivalent
attachment may be applied; the machine is provided with starting and stopping
gear.
"
The driving mechanism afore mentioned is also applicable to machines other
than sewing machines such for example as bicycles, tricycles or other analogous
machines.
For guiding the cotton or thread upon the shuttle bobbin when the same is
being wound or for other analogous purposes, a cam wheel is mounted in front of
the bobbin, that is to say, in the position in which it is held within the winder.-
Upon the periphery of this cam there is formed an endless groove running
diagonally across the said cam, the horizontal distance between the extreme points
of this groove being equal to the distance which the thread being wound has to
travel from one end to the other of the bobbin; so that in every revolution the
thread passing over the cam at the groove is carried by it into the position required
according to the gradual travel of the same on the bobbin.-The necessary motion
may be imparted to the cam wheel from the winder by means of toothed, or by
any other suitable form of gearing; or it may be geared with the shuttle containing
the bobbin when it is used as herein before mentioned in winding the thread on the
bobbin.
Another part of this Invention relates to the means for setting the needle in the
needle bar of the machine.-The needle bar under these present improvements is
constructed so that the needle when placed in the said bar comes against a stop
situated at the required distance up the needle bar, so that when the needle is
pressed up into the same it is in the required position for tightening up; or the
Deedle may have formed upon it a collar which comes against the lower end of the
holder when pressed into place.-These improvements obviate the necessity of
adjusting the position of the needle as is at present ordinarily required.
Another method of holding the needles in the needle bar consists of splitting the
end of the needle bar into two or more parts and on the outside of these parts a
cone is formed upon which a correspondingly shaped collar is forced down and
draws the parts tightly around the needle in its act of holding the same.-For
releasing the needle the aforesaid collar is raised, and thereby the divided parts of
the needle bar spring outwards and thus leave the needle free to fall from the
bolder. A stop may also be fitted to this form of holder so as to obviate the
necessity of adjustment.