IMPROVEMENTS IN SCREWS AND SCREW DRIVERS
Year: 1875

page_text: LETTERS PATENT to William Knell, of Park House, Farnborough, in
the County of Hants, for the Invention of " IMPROVEMENTS IN SCREWS
AND SCREW DRIVERS."
Sealed the 1st February 1876, and dated the 3rd November 1875.
PROVISIONAL SPECIFICATION left by the said William Knell at the
Office of the Commissioners of Patents, with his Petition, on the
3rd November 1875.
I, WILLIAM KNELL, of Park House, Farnborough, in the County of
Hants, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SCREWS AND SCREW DRIVERS," to be as follows :
In constructing screws according to my Invention I form two or more
slits across the head of the screw, by preference two slits, crossing one
another at right angles, and at the centre of the head I form a hole
downwards into the stem of the screw. The screw driver I form with
corresponding blades or edges, and with a projecting point at the centre.
This point is made longer than the slits across the screw heads, so that in
applying the screw driver to the head of a screw the point of the driver

page_text: has first to be inserted into the central hole in the screw, and then forms
a guide to steady the screw driver, and keep it central with the screw
head; all difficulty in adjusting the driver to the head of the screw is
thus avoided.
Screws having one slit only across the head may in a similar manner
be formed with a central hole to steady the screw driver and screw, and
keep them central with one another.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Knell in the Great Seal Patent Office
on the 3rd May 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
KNELL, of Park House, Farnborough, in the County of Hants, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of November, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said William Knell, Her special
license, that I, the said William Knell, my executors, administrators,
and assigns, or such others, as I, the said William Knell, 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 "IMPROVE-
MENTS IN SCREWS AND SCREW DRIVERS," upon the condition (amongst others)
that I, the said William Knell, 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 Inven-
tion, 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

page_text: Figures 7 represent a screw with but one slit across the head; and
Figures 8 show a corresponding screw driver, but the cross slits are
preferred.
I claim the construction of screws and screw drivers, substantially as
described.
In witness whereof, I, the said William Knoll, have hereunto set
my hand and seal, this 2nd day of May, in the year of our
Lord One thousand eight hundred and seventy-six.
6