IMPROVEMENTS IN SEWING MACHINES
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by James Galloway Weir at the
Office of the Commissioners of Patents, with his Petition, on the
21st May 1875.
I, JAMES GALLOWAY WEIR, of Carlisle Street, Soho Square, in the
County of Middlesex, Sewing Machino Manufacturer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN SEWING MACHINES,"
to be as follows:-
-
My said Invention relates to various improvements which are designed
to simplify the construction of sewing machines, to reduce the cost of
their manufacture, to increase their efficiency and durability, and to
render them more easy of operation and adjustment.
One part of my said Invention relates to improved feed mechanism
which is constructed and arranged as follows:-The feed bar is a piece
of steel or other suitable metal, and is nearly of a U form, with one side
bar shorter than the other; this piece is placed under the cloth plate
and has the usual roughened surface on a piece formed on the long bar,
and which projects through a slot in the said plate. The extremity of
this long bar lies in contact with one arm of a lever, whose fulcrum is

page_text: 1
carried on an adjustable rod or bar. The other arm of this lever is in
contact with one end of a short sliding rod or bolt, whose other end rests
upon the periphery of a cam on a shaft which receives rotary motion
from the driving wheel of the machine. This cam moves the said bolt
to and fro, and thereby causes the lever to oscillate on its fulcrum, and
this oscillation of the lever imparts the required endwise motion to the
feed bar. The latter at its end opposite to that which bears on the said
lever is fitted to slide between guides, and oscillates upon a pin or bolt
secured in the under side of the cloth plate or in any suitable manner,
and this end of the said feed bar is pressed by a spring which counteracts
the movement of the aforesaid oscillating lever. The short arm of the
U shaped feed bar lies upon the top of the aforesaid cam, and the said
feed bar receives its vertical motion from the said cam. I thus obtain
both movements of the feed from one cam instead of employing two
cams in the ordinary manner.
5
The aforesaid adjustable rod which carries the fulcrum of the oscillating
lever is fitted to slide between guides, and is extended nearly to the rear
of the machine. It has at its rear extremity a pin or stud which projects
up through a slot in the cloth plate, and is provided with a knob or
button; by sliding this knob or button endwise the said rod may be
adjusted to so vary the action of the oscillating lever as to produce any
required length of feed. The guides of the said sliding rod are provided
with a pin or other stop to prevent the said rod moving too far in either
direction.
Another part of my said Invention relates to a peculiar construction
and arrangement of the presser bar, the said presser bar instead of
being a round bar fitted to slide inside the head of the machine is a flat
piece fitted to slide upon one side of the head. For this purpose I use a
rather thin piece of steel or other suitable metal, and form on the lower
end thereof the presser foot. The vertical portion of this flat bar is
slotted and is held upon the side of the head by screws passed through
the slots, and so fitted therein as to hold the bar securely in place while
permitting it to slide freely as required for its vertical adjustment. The
said presser bar is forced down by a simple flat spring, which is fixed on
the side of the frame of the machine and fitted in a notch in the upper
part of the said bar; I thus avoid the use of the ordinary arrangement
of the spiral spring, which is continually liable to be clogged with oil
and is otherwise inconvenient, For raising the said presser bar I

page_text: employ a small cam or excentric placed below the spring and fixed on a
pin or bolt which turns in a bearing in the frame, and is provided with
a small lever or handle, whereby it is adjusted. By this peculiar
arrangement of the needle bar and spring I am enabled to reduce the
size of the head of the machine and thus give to the same a more
ornamental and lighter appearance than heretofore.
Instead of forming the needle bar of one solid piece of malleable cast
iron or other suitable metal as beretofore, I construct it of a number of
pieces of thin steel which are first stamped from a thin sheet or plate of
this metal, then fitted together and secured by rivetting or otherwise,
and then finished on their edges by any suitable tool. By this con-
struction I obtain a needle bar at a diminished cost, and which is.
stronger and more durable than the needle bars formed in the usual
manner.
Instead of forming the lower end of the needle bar with a socket for
the reception of the needle, and with a pinching screw at one side of the
said socket for securing the needle therein, I provide the needle bar with
a clamp for securing the needle. This clamp is a small piece of steel or
other suitable metal with a flat portion which is fitted against the front
face of the needle bar, and is secured upon the said bar by a screw stem
formed on the clamp, and extending through a hole in the needle bar
and provided with a nut on the rear side of the same. The front surface
of the needle bar and the adjacent face of the clamp piece are grooved
to fit the shank of the needle, and when the latter is properly placed
between the bar and the clamp it is made tight by means of the afore-
said nut. This method of securing the needle allows the same to be very
readily removed and replaced, and greatly increases the facility for its
accurate adjustment, and obviates the necessity for a screwdriver or other
implement.