IMPROVEMENTS First
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Marshall Henry Pearson at the Office
of the Commissioners of Patents on the 28th November 1881.
MARSHALL HENRY PEARSON of Leeds in the County of York
IN SEWING MACHINES
"
"IMPROVEMENTS
Firstly. In my improvements I use the ordinary straight needle the needle bar
for which is fitted in a slide which is hinged or pivotted at its upper end. To this
is given an intermittent radial reciprocating motion by a cam on the driving shaft
and the required vertical movement is imparted to the needle bar through a heart
cam attached to the slide by a crank or cam arrangement on the driving shaft
The radial movement is imparted to the slide when the needle has passed
through its work and at rest; this radial movement imparts a lateral movement to
the needle and feeds the material forward but prior to imparting this lateral
movement to the material I cause the needle to rise slightly for the purpose of
relieving the leather from the throat piece. I also cause the presser foot to rise a
little for the purpose of allowing the leather to be relieved as above stated, but it
is afterwards brought down again onto the. leather with a firm pressure and locked
there. The object of the locking being to prevent the friction of the needle lifting
the presser foot. The locking arrangement is effected through a lever and spring
and relieved by an intermittent tappit arrangement. The lifting movement for
the presser foot has also a locking motion applied thereto, this is actuated by a
tappit cam through a toggle arrangement. The above named locking is effected
in a similar manner to that described in the Specification of the Letters Patent
granted to me the 28th January 1879 No. 348.
I employ a circular shuttle which is of the same construction as that described
in the Specification of the Letters Patent granted to me the 12th August 1880
No. 3294, this is mounted in a box on the end of a short hollow spindle. A rotary
reciprocating motion is imparted thereto and for this purpose I provide an internal
screw within the hollow short spindle and within the interior of the spindle is
provided a piston having a stud thereon fitted so as to slide freely within the
internal screw. To the piston is imparted a reciprocating motion by means of a
cam on the driving shaft through a suitable connecting rod imparting thereby

page_text: through the stud and internal screw the required rotary reciprocating motion to
the shuttle.
The motion to the thread lever is imparted by a bell cam on the driving shaft
this operates in conjunction with a thread locking device mounted on the needle
slide carrier. The thread continues to be locked during the whole of the upward
movement of the thread lever. I couple to the thread lever a tube by preference of
brass or copper this is mounted at its end in a frictional bearing, through this
tube which is heated by any convenient means is passed the thread already
saturated with wax for the purpose of keeping it soft. The upward movement of
the tube is imparted by the thread lever to which it is attached for the purpose of
providing thread for the varying thicknesses of material or length of stitch.
The tube is drawn downwards by the thread the distance depending upon the
amount thereof required. This movement may in some cases be reversed.
I also provide another heated tube which is secured to the front of the needle
bar carrier through which the thread passes on its way to the needle after
having left the thread lever.
The shuttle box end is also heated.
This machine may also be employed with unwaxed threads when such is the case
the above mentioned tubes and shuttle box end need not be heated.
Secondly. In combination with the use of the hereinbefore mentioned circular
shuttle I employ for some purposes an awl which pierces the hole for the needle
this may either be mounted on the needle bar and side by side with the needle
fitted so that their distance apart can be adjusted to suit the length of stitch. Or
the needle and awl may be mounted on separate slides. In this arrangement
the awl pierces the hole and feeds the material leaving the hole clear for the
needle with its thread to pass through. The lateral and vertical movement for
suitable levers and cams of ordinary
the needle and awl are produced by
construction.
Thirdly. I apply also a curved awl in combination with the curved eye pointed
needle employed in machine for which Letters Patent were granted to me dated
12th August 1880 No. 3294. This may be either on the same lever as the
needle having an arrangement whereby their distance apart may be regulated
or when preferred they may be mounted on separate levers.
The required
radial and lateral movements being imparted thereto from suitable cams or their
equivalents.
By the above arrangements finer needles may be employed than when the
needle alone is used for piercing the material.