IMPROVEMENTS. IN SEWING MACHINES
Year: 1874

page_text: LETTERS PATENT to Chaim Groubman; of Odessa, in the Empire of
Russia, and temporarily of Great Portland Street, in the County
of Middlesex, for the Invention of "IMPROVEMENTS. IN SEWING
MACHINES."
99.
Scaled the 29th May 1874, and dated the 4th April 1874.
:
PROVISIONAL SPECIFICATION left by the said Chaim Ĝroubman at
the Office of the Commissioners of Patents, with his Petition, on
the 4th April 1874.
I, CHAIM GROUBMAN, of Odessa, in the Empire of Russia, and teni-
porarily of Great Portland Street, in the County of Middlesex, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN SEWING
MACHINES," to be as follows:
.
i
This Invention relates to improvements in sewing machines in which
the needle bar is actuated by a horizontal shaft geared with the main
, shaft of the machine, and the Invention consists in employing a rock
Ehaft operated by a crank motion from the main shaft instead of a

page_text: rotating shaft for actuating the needle, whereby all toothed gearing is
dispensed with, and the machine is consequently rendered noiseless and
works with less power and friction. The said rock shaft is mounted in
bearings at the back of the fixed arm of the frame, and at the end
of said shaft are fixed crank arms, the one at the needle end being
slotted to receive a stud on the needle bar, whilst the other is, by a con-
necting rod jointed to its extremity, connected to a crank pin on the
band pulley on the main shaft. The radius of the arm to which the
connecting rod is jointed is greater than that of the crank pin, so that
the rotation of the latter only rocks the needle shaft.
RI
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SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Chaim Groubman in the Great Seal Patent Office
on the 1st October 1874.
"
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHAIM
GROUBMAN, of Odessa, in the Empire of Russia, and temporarily of
Great Portland Street, in the County of Middlesex, send greeting..
"י
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of April, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Chaim Groubman, Her special licence
that I, the said Chaim Groubman, my executors, administrators, and
assigns, or such others as I, the said Chaim Groubman, 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 Invention for "IMPROVEMENTS IN
SEWING MACHINES," upon the condition (amongst others) that I, the said
Chaim Groubman, 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,

page_text: 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 Chaim Groubman, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement reference being had to the accompanying Sheet
of Drawings, and to the letters and figures marked thercon (that is to
say)
'
My Invention relates to improvements in that class of sewing
machines in which the needle is fixed in a vertical slide bar actuated by
a horizontal shaft, and the Invention consists in employing a rock shaft
operated by a crank motion from the main shaft instead of a rotating
shaft for actuating the needle bar, whereby all toothed gearing is
dispensed with, and the machine is consequently rendered noiseless and
works with less power and friction.
.
In order that the Invention may be more readily understood I have
illustrated in the accompanying Drawings a single thread "sewing
machine in which the needle is worked by a rock shaft as above
mentioned.
Figure 1 is a front clevation of the machine, and Figures 2 and 3 aro
end elevations of the same.
A is the bed plate of the machine, and B the fixed bracket arm of
the frame. C is a horizontal driving shaft mounted beneath the bed
plate A, carrying at one extremity the rotating looper D, and receiving
motion at the other end by a band from a treadle motion. E is the
needle bar working in guides in the head of the arm B. All these parts
are constructed and operate in the usual manner, except the looper D,
which is slightly different in form to those generally used. F is a rock
shaft mounted in bearings G, G, fixed at the back of the arm B. To
the one extremity of this shaft is fixed a crank arm H connected with
the needle bar E by a screw stud I fixed on the latter passing through
a slide block K working in a slot L in the end of the arm H, and
through a second slide block M working up and down in a vertical slot
or guide N in the end of the arm B. At the other end of the rock
shaft F is fixed a similar crank arm O couplied by a connecting rod P
to a crank pin R fixed on a disc keyed on the rotary driving shaft C

page_text: from which the rock shaft E thus receives motion. The radius of the
arm O.being greater than that of the crank pin R, the rotary motion of
the latter thus imparts a rocking motion to the shaft F, thereby imparting
up-and-down motion to the needle bar through the arm H.
Besides dispensing with toothed gearing I am enabled to make the
arm B of the frame of greater.length than is convenient when a rotary
shaft is employed, so that ample space is afforded for moving the work
about on the table A..
Having described the nature of my Invention, and the manner of
performing the same, I declare that what I claim as the Invention to be
protected by the. herein-before in part recited Letters Patent is, operating
the needle bar by a longitudinal rock shaft F actuated by an arm O and
connecting rod P from a crank on the main shaft C, said shaft F being
connected to the needle bar by an arm. H and slide blocks working in
guides, the whole combined. and arranged substantially as shown and
described.
t
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In witness whereof, I, the said Chaim Groubman, have hereunto
2
set my hand and. seal, this Thirtieth day of September, in the
year of our Lord One thousand cight hundred and seventy-four...