IMPROVEMENTS IN SEWING MACHINES
Year: 1870

page_text: LETTERS PATENT to Joseph Buchanan Robertson, of Lurgan, in
the County of Armagh, in Ireland; Mechanic, for the Invention
of "IMPROVEMENTS IN SEWING MACHINES."
Sealed the 20th December 1870, and dated the 18th October 1870.
PROVISIONAL SPECIFICATION left by the said Joseph Buchanan
"
.
Robertson at the Office of the Commissioners of Patents, with his
Petition, on the 18th October 1870.
I, JOSEPH BUCHANAN ROBERTSON, of Lurgan, in the County of
Armagh, in Ireland, Mechanic, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN SEWING MACHINES," to be as
follows:-
My Invention relates to sewing machines adapted for the production
of the French vein or hem stitch and consists in effecting a lateral
movement of the arm which carries the needle by means of a grooved
cam placed on a stud or countershaft and moved by suitable gearing

page_text: from the main shaft or axle in lieu of a lateral movement of the entire
frame as heretoforc practised.
And also in effecting the progressive and retrogressive movements of
the feed by means of another grooved cam placed on the same stud or
countershaft and moved by the same gearing in lieu of a cam and spring
as heretofore used.
“SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Buchanan Robertson in the Great Seal
Patent Office on the 17th April 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
BUCHANAN ROBERTSON, of Lurgan, in the County of Armagh, in
Ireland, Mechanic, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Eighteenth day of October, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Joseph Buchanan Robertson, Her special
licence that I, the said Joseph Buchanan Robertson, my executors,
administrators, and assigns, or such others as I, the said Joseph
Buchanan Robertson, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN SEWING MACHINES," upon the condition
(amongst others) that I, the said Joseph Buchanan Robertson, my.
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Joseph Buchanan Robertson, do
hereby declare the nature of my said Invention, and in what manner

page_text: the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the accom-
panying Drawings, and to the letters and figures marked thereon that
is to say:
The said Invention consists in further improved means of producing
the stitches commonly called and known as the French vein or hem
stitch by machinery.
The hem stitch work, by which name I shall herein-after designate
the effects capable of being produced by this machinery, consists of a
piece of fabric prepared in the ordinary way folded in or down upon
itself, and having its fold firmly held by a constantly repeated or
recurring series of three stitches which at the same time produce a
V shaped opening in the single ply of the fabric. Each stitch employed
may be either a single thread chain stitch or a lock stitch as commonly
made by a sewing machine.
The improved mechanism for producing the hem stitch work consists
of certain attachments fitted upon and connected with sewing machines
by means of some or one of which a lateral movement is effected in the
arm which carries the needle in lieu of the lateral movement of the
plate or the frame, as heretofore practised, and by means of another
or others of which the progressive and retrogressive movements of
the feed are effected without the aid of a spring and the cam heretofore
used.
For the purpose of giving a lateral motion to the needle arm, by which
term I mean to designate that part of the machine which carries the
needle, and is made moveable, I employ a crank lever moved by a
grooved disc cam placed on a stud or countershaft. The crank lever
is connected with the needle arm by means of a stud or pin; and in
order that I may regulate the extent of the lateral movement of the
needle arm I provide the stud or pin with a screw and nut, and cause
the crank lever and needle arm to be slotted in correspondence with
each other, so that the stud or pin may be moved nearer to or farther
from the centre or fulcrum of the lever as desired.
And for the purpose of effecting the progressive and retrogressive
movements of the feed instead of using a disc cam to produce the
progressive movement of the feed and a spring, to produce the reverse
movement as heretofore practised I employ a grooved cylinder or barrel.
cam which receives and acts in both directions upon a pin fixed in a

page_text: short lever connected by a stud. or pin with another lever depending
from one end of a rocking shaft having at the other end a depending
grooved arm or bracket in which the feed bar slides. The two levers
last mentioned I also cause to be correspondingly slotted, so that the
connecting stud or pin may be moved nearer to or farther from the
rocking shaft according to the length. of progressive and retrogressive
movements desired. The feed bar is lifted by a lever similar to the
ordinary feed lift or pressure lever, and is held upon the cloth by an
elastic band or spring as heretofore practised.
And in order that the said Invention may be fully understood I shall 1
now proceed to describe the same by a reference to the several Figures,
on the Sheet of Drawings hereunto annexed, the same letters of
reference indicating the same or corresponding parts throughout all the.
Figures.
Figure 1. is a plan of a portion of the machine, and shews the improve---]
ments herein-before mentioned; Figure II. is a front view of a portion
of the machine and shews the improvements in their relation to that
position; Figure III. is a back view of a portion of the machine and.
shews the improvements in their relation to that position; Figure IV.
is an end view of a portion of the machine, and shews the improvements 2
in their relation to that position, and Figure V. is a view. of the grooved.
arm or bracket and the feed bar.
a is the crank lever; b is the grooved disc cam placed on a counter-.
shaft
0 ; d is a screwed stud or pin connecting the crank lever a with
the needle arm e and provided with a nut f; g, g, are corresponding
slots cut in the crank lever and needle arm; % is the centre on which
the crank lever a moves; k is the grooved cylinder or barrel cam which
acts in both directions upon the short lever 1; m is a screwed pin
connecting the short lever 7 with the lever n depending from one end
of the rocking shaft o; p, p, are the corresponding slots cut in the
levers and n, and q is the nut with which the pin m is provided for.
adjustment; r is the grooved arm or bracket depending from the other.
end of the rocking shaft o, and s is the feed bar which slides in the
arm or bracket r; t is the lever by which the feed bar is lifted.
Having now described the nature of the said Invention and in what
manner the same is to be performed I would have it understood that
I do not claim the use of sewing machines except when the same are
constructed or adapted specially for the production of hem stitch work.

page_text: as herein-before described, nor do I claim the use of any of the
mechanical parts which form the sewing machine employed by me for
the production of hem stitch work, but I claim,-
First. The production of hem stitch work by the use of sewing
machines having mechanisms or attachments constructed, fitted, and
applied as herein-before described.
Secondly. The combination and arrangement of parts constituting
the sewing machine, constructed and adapted as herein-before described
for the production of hem stitch work.
In witness whereof, I, the said Joseph Buchanan Robertson, have
hereunto set my hand and seal, this Fourteenth day of April,
in the year of our Lord One thousand eight hundred and seventy-
one.