IMPROVEMENTS IN SEWING MACHINES
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by George Slater at the Office of the
Commissioners of Patents on the 19th January 1878.
GEORGE SLATER, of City Road, in the County of Middlesex, Engineer.
"IMPROVEMENTS IN SEWING MACHINES."
My Invention relates to improvements in sewing machines, and is more especially
designed to adapt the same advantageously to the sewing of straw braid.
The said improvements comprise,—
1st. A novel contrivance, which I term an elastic or automatically adjustable
compound or double presser foot, which is designed especially for facilitating the
sewing or stitching together of two or more separate parts or pieces of straw braid,
cloth, leather, or other like materials of any required thickness, and which, by
its capability of adjustment will adapt itself to different thicknesses of such
materials.
2nd. A device for steadying or preventing the lateral deviation or oscillation of
the said adjustable presser foot or other presser foot of a sewing machine, and for
reducing to a minimum the friction and wear due to the motion of the presser
bar.
The aforesaid adjustable or elastic presser foot is constructed in two parts or
pieces of iron, steel, or other suitable metal. One of these parts, which I term the
fixed part, is attached to the ordinary presser bar of the machine to which my
Invention is applied, while the other part is fitted to the said fixed part in such a
manner that it is automatically adjustable thereon. The bearing surface of the
said fixed part and that of the said adjustable part are arranged to press upon the
work as it is fed through the machine, and it is the chief object of this part of my
Invention to ensure the proper amount of pressure upon both the single thickness
and the double or manifold thicknesses of the straw braid or other material,
and to ensure the automatic adjustment of this pressure to different thicknesses
thereof. For this purpose the said adjustable part of the presser foot is con-
nected with the fixed part by means of vertical guide pins or otherwise in such
a manner that the said adjustable part is capable of sliding or moving ver-
tically on the said guide pins and against the side of the fixed part, and I attach
to one of the parts a small flat spring or other suitable spring so arranged to

page_text: act on the other part as to tend always to depress the adjustable part, and keep its
bearing or pressing surface below that of the fixed part of the presser foot, and by
the action of this spring, in combination with the ordinary spring on the presser
bar, the two parts on the said bar will be caused to act with required pressure upon
the single and double or manifold thickness of the work, and will adapt themselves
automatically to work or material of any thickness. In addition to this automatic
vertical adjustability of the presser foot I render the same adjustable laterally to
vary the distance of the sewing or stitching from the edge of the work to make
either a wide or a narrow lap as desired. For this purpose I place between the fixed
and adjustable parts of the presser foot an intermediate plate, to which are secured
the aforesaid guide pins. The said fixed part has slots, into which project pins or
studs from the said intermediate plate, which slots and pins permit the said inter-
mediate plate and the aforesaid adjustable part of the foot to move laterally on the
fixed part to effect the required adjustment, as above specified. One of the said
pins is provided with a pinching nut, whereby the parts of the rest may be secured
when adjusted laterally into any required position.
The aforesaid adjustable part of the presser foot is provided with an arm or bar,
which projects forward over the side of the machine on which the operator sits.
This arm or bar guides the work as it is fed forward, and is bent or curved down-
ward for the purpose of keeping the single piece or thickness parallel with the work
upon which it is to be sown or stitched.
In some instances, instead of curving or bending the said arm or bar downward,
I bend the same laterally outward, or provide it with a tongue or finger projecting
outward laterally at right angles to the said arm or bar; or I may use a vertical
bar attached adjustably to the head of the machine, and provided at its lower end
with a laterally or horizontally projecting tongue or finger.
The aforesaid device for steadying or preventing the lateral oscillation of the
presser bar consists of a lever or arm which is fulcrummed or pivotted at or near
the central part of the fixed arm of the machine, and whose outer end is fitted
upon a stud or pin fixed in and projecting from the upper end of the presser bar.
The said lever has a slot or is otherwise so fitted upon its fulcrum pin as to permit
it to slide end wise while vibrating thereon.
The bosses or eyes at the fulcrum and extremity of the said lever are made of
such a length as to afford sufficient bearing upon the said pins or studs to ensure
steadiness and durability, while the arrangement of the lever is such as to effect the
desired object without impairing or impeding the automatic or other adjustment of
the aforesaid presser foot.
The above-described improvements may be embodied in machines especially con-
structed therefor, and may also be provided as an attachment to existing sewing
machines to adapt them to the sewing of straw braid or similar work.