IMPROVEMENTS IN SCREW PRESSES
Year: 1859

page_text: LETTERS PATENT to Edward Hammond Bentall, of Heybridge, near
Maldon, in the County of Essex, Ironfounder, for the Invention of
"IMPROVEMENTS IN SCREW PRESSES."
Sealed the 27th March 1860, and dated the 29th September 1859.
PROVISIONAL SPECIFICATION left by the said Edward Hammond Bentall
at the Office of the Commissioners of Patents, with his Petition, on
the 29th September 1859.
I, EDWARD HAMMOND BENTALL, of Heybridge, near Maldon, in the County
of Essex, Ironfounder, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SCREW PRESSES," to be as follows:-
My Invention of improvements in screw presses relates to a novel mode of
constructing screw presses whereby increased power is obtained; and consists
in the employment of a combination of screws of different pitch, one working
in the other and the outermost screw in a box or female screw in the ordinary
manner. When therefore one of the combined screws is turned round, the
pressing plate attached to the bottom thereof will be depressed an amount

page_text: corresponding to the pitch of that screw, and when this is screwed up as
tightly as possible, the other screw will be brought into play and will still
further depress the pressing plate. The relative pitch of the screws must of
course depend upon the power required, and the purpose for which the is
press
intended to be wood and unen the material to be onerated upon.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Hammond Bentall in the Great Seal Patent Office
on the 28th March 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
HAMMOND BENTALL, of Heybridge, near Maldon, in the County of Essex, Iron-
founder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of September, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-third year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Edward Hammond Bentall, Her special license that I, the said
Edward Hammond Bentall, my executors, administrators, and assigns, or
such others as I, the said Edward Hammond Bentall, my executors, adminis-
trators, 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 SCREW PRESSES," upon the condition
(amongst others) that I, the said Edward Hammond Bentall, by an instrument
in writing under my hand and seal, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to be per-
formed, 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 Edward Hammond Bentall, 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 Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say):-
My Invention of improvements in screw presses relates to a novel mode of

page_text: manner.
constructing screw presses whereby increased pressure is obtained, and consists
in the employment of a combination of screws of different pitch, one working
in the other and the outermost screw in a box or female screw in the ordinary
When therefore one of the combined screws is turned round, the
pressing plate attached to the bottom thereof will be depressed an amount
corresponding to the pitch of that screw, and when this is screwed down as
tightly as possible, the other screw will be brought into play and will still
further depress the pressing plate. The relative pitch of the screws must of
course depend upon the power required, and the purpose for which the press
is intended to be used, and upon the material to be operated upon.
In the accompanying Drawing, Fig. 1 is a plan view, and Fig. 2 a front
elevation of a letter-copying press constructed according to my Invention;
Fig. 3 is a detached sectional view of the screws for working the pressing
plate. a is the foundation plate of the press; b, b, the moveable top or press-
ing plate, which is suspended from the lower end of the inner screw c, which
is turned by means of a hand wheel d, and passes through and works in a
female screw formed inside the larger screw e, as seen best in Fig. 3. The
large screw e in its turn works in a nut or female screw tapped or formed in
the strong cross piece f, which is supported by the side columns 9, 9, and
receives the thrust of the combined screws. A hand lever h, h, is fixed on
the end of the outer or larger screw e for the purpose of turning the same.
The several parts operate in the following manner:-The book or article to
be pressed is placed on the bed or foundation plate a, and the pressing plate
b, b, is brought down on to the top of the book by turning the hand wheel d,
and thereby lowering the inner screw c. As much pressure as can be con-
veniently applied by means of the hand wheel d must then be given, after
which a still greater pressure may be applied by turning the hand lever h, h,
and thereby causing the outer screw e to descend in its nut. It will be under-
stood from the foregoing description that the inner screw c, which works in a
female screw cut in the inside of the large screw e, is of different pitch to that
of the outer screw e, and that although the rotation of the outer screw e on the
inner screw c will have a tendency to draw up this latter, the effect of, the
difference in pitch between the screws cand e will be that the inner screw c
and the pressing plate 6 will be forced down a distance and at a rate of speed
equivalent to that which is due to the difference in pitch between the two
screws, and a very greatly increased pressure will be the result.
Having now described my Invention of improvements in screw presses, and
having explained the manner of carrying the same into effect, I claim as the

page_text: Invention secured to me by Letters Patent as aforesaid the mode herein set
forth of constructing screw presses.
In witness whereof, I, the said Edward Hammond Bentall, have here-
unto set my hand. and seal, the Twenty-sixth day of March, in the
year of our Lord One thousand eight hundred and sixty.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
E. H. BENTALL. (L.S.)