IMPROVEMENTS IN MACHINES FOR GINNING COTTON
Year: 1872

page_text: LETTERS PATENT to Benjamin Dobson, Thomas Henry Rushton, and
William Dobson, all of Bolton, in the County of Lancaster,
Machine Makers, for the Invention of "IMPROVEMENTS IN MACHINES
FOR GINNING COTTON."
Sealed the 26th July 1872, and dated the 10th February 1872.
PROVISIONAL SPECIFICATION left by the said Benjamin Dobson,
Thomas Henry Rushton, and William Dobson at the Office of the
Commissioners of Patents, with their Petition, on the 10th February
1872.
We, BENJAMIN DOBSON, THOMAS HENRY RUSHTON, and WILLIAM
DOBSON, all of Bolton, in the County of Lancaster, Machine Makers, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
MACHINES FOR GINNING COTTON," to be as follows:-
This Invention consists in certain improvements upon the cotton gius
known as the knife roller gins. These machines consist principally of a
knife roller partly surrounded by a grid, a gin roller, and a doctor knife.
Now our Invention consists in an improved mode of constructing the
grid partly surrounding the said knife roller, and in the mode of

page_text: regulating the position of the doctor knife. The grid of the knife roller
instead of being made of concentric rings of round wire we now make of
longitudinal, angle, or other shaped wires, secured at the ends and at one
or more intermediate places to metal bands. These improved grids
facilitate the escape of the seeds when the fibres are stripped off them,
and separate dust, bits of shell, and other impurities from the fibres.
The doctor knife, which is placed between and under the knife roller and
gin roller, is regulated by set screws at each end of the machine. These
set screws pass through projections cast to the back or frame of the
doctor knife and through other projections cast on the frame sides,
whereby the position of the doctor knife can be regulated with great
accuracy.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Benjamin Dobson, Thomas Henry Rushton, and
William Dobson in the Great Seal Patent Office on the 9th
August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, BENJAMIN
· DOBSON, THOMAS HENRY RUSHTON, and WILLIAM DOBSON, all of
Bolton, in the County of Lancaster, Machine Makers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of February, in the year
of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Benjamin Dobson, Thomas Henry
Rushton, and William Dobson, Her special licence that we, the said
Benjamin Dobson, Thomas Henry Rushton, and William Dobson, our
executors, administrators, and assigns, or such others as we, the said
Benjamin Dobson, Thomas Henry Rushton, and William Dobson, our
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
MACHINES FOR GINNING COTTON," upon the condition (amongst others) that
we, the said Benjamin Dobson, Thomas Henry Rushton, and William

page_text: Dobson, our executors or administrators, by an instrument in writing
under our, 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 we, the said Benjamin Dobson, Thomas
Henry Rushton, and William Dobson, do hereby declare the nature
of our said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following
statement (that is to say) :-
Our Invention is applicable to the cotton gins known as the “knife
roller cotton gins," and these gins consist principally of a knife roller
partly surrounded by a grid, a gin roller, and a doctor knife. The grid
of the knife roller instead of being made of concentric rings of round wire
we now make of angle or other shaped wire placed in the same line as
the axis of the knife roller. The doctor knife, which is placed between
and under the two rollers, is set by regulating screws at the outside of
the framing.
The object of our Invention is to clean the cotton more effectually
than heretofore, and to facilitate the adjustment of the parts.
And in order that our Invention may be fully understood, and readily
carried into operation, we will proceed to describe the accompanying
Sheet of Drawings, reference being had to the figures and letters marked
thereon.
Fig. 1 is an elevation, Fig. 2 a transverse section, Fig. 3 a front
view, and Fig. 4 a plan of a knife roller cotton gin constructed according
to our improvements.
a is the knife roller, consisting of plates set diagonally on an axle,
which in revolving delivers the cotton to gin roller b. The doctor
knife c, which is placed under the rollers a and b, is pressed against the
surface of the gin roller 6 by the springs d as usual, and the lower edge
of the doctor knife rests upon a shoulder of the cross beam e. The ends
of this beam are secured to the frame sides of the machine by bolts
passing through slots, and to each end is cast an ear, in which is a
regulating screw f. The heads of these regulating screws pass through

page_text: projections on the frame sides, by which arrangement when the doctor
knife requires adjusting the attendant can raise or lower it without
stopping the machine. The knife roller is partly surrounded by the
grid g, which consists of angle or other wires placed parallel to the axis
of the roller and secured at the ends and in one or more intermediate
places by metal bands. This improved mode of constructing the grid
facilitates the escape of the seed when the fibres are stripped off, and
separates the fibres from the dust, shell, and other impurities. The
rollers a and b are turned round by a crossed and an open strap from a
drum on the driving shaft, the relative speeds of the rollers being varied
by altering the pulleys on the axles of the rollers as usual. The seed
cotton to be cleaned is spread on the table h, and drops into the hopper
formed by the inclined board i and the top cross stay j, the lower part of
which is curved to fit the surface of the knife roller a. The fibres
caught by the gin roller pass between it and the doctor knife and fall
under the roller a, while the seeds, which are constantly agitated by the
knife roller when stripped, fall through the grid g into the receptacle
formed by the lower cross stay k and the partition 1.
Having thus stated the nature of our Invention, and described the
manner of performing the same, we declare that we claim,-
First. The improved mode of regulating the position of the doctor
knife as described.
And Secondly. Making the grid of the knife rollers of wires or rods
placed parallel to the axis thereof as described.
In witness whereof, I, the said Thomas Henry Rushton, have
hereunto set my hand and seal, this Seventh day of August
One thousand eight hundred and seventy-two.
Witness to the signature of
Tho. H. Rushton,
JOHN LEIGH,
Aldred,
THO³. H. RUSHTON. (L.S.)
Clerk.