AN IMPROVED TUNING KEY FOR PIANOFORTES AND HARPS."
Year: 1875

page_text: LETTERS PATENT to John Tench, of Brentford, in the County of
Middlesex, for the Invention of "AN IMPROVED TUNING KEY FOR
PIANOFORTES AND HARPS."
PROVISIONAL SPECIFICATION left by the said John Tench at the
Office of the Commissioners of Patents, with his Petition, on the
21st September 1875.
I, JOHN TENCH, of Brentford, in the County of Middlesex, do hereby
declare the nature of the said Invention for "AN IMPROVED TUNING KEY
FOR PIANOFORTES AND HABPS," to be as follows :-
-
My Invention relates to an improvement in tuning keys for pianofortes
and harps, and consists of an arrangement whereby the operation of
tuning is greatly facilitated, less power being required to turn the wrest
pins.
According to my Invention the socket of the key which fits on the

page_text: wrest pins is not formed on the end of the spindle of the key as usual,
but is made separate and geared therewith by a train of wheels, wheroby
the power transmitted is multiplied at the expense of motion, the socket
being caused to rotate slower than the handle.
A convenient arrangement is to enclose the gear in a box fitted on the
key spindle, which turns therein, the box being hold stationary by a pro-
jecting arm abutting against one of the adjacent wrest pins or other
stop. A toothed pinion keyed near the inner extremity of the spindlo
gears with a larger wheel on another axis mounted in said box, which
axis also carries a small pinion gearing with a larger wheel on a short
axis in line with the key spindle, to which the key socket is attached.
The latter is preferably made detachable from its axis, so as to be readily
replaced if desired, and the extremity of the spindle is preferably fitted
to turn in a recess in the extremity of the socket axis for the sake of
strength. A spring is fitted within the box, and embraces one of the
wheels to act as a brako to prevent the parts turning so loosely on the
key spindle as to render the use of both hands necessary in applying
the key to the wrest pin.
SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said John 2
Tench in the Great Seal Patent Office on the 21st April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
TENCH, of Brentford, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of September, in the 2
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 successors,
give and grant unto me, the said John Tench, Her special licence
that I, the said John Tench, my executors, administrators, and
assigns, or such others as I, the said John Tench, executors, 3
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

page_text: within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVED TUNING KEY
FOR PIANOFORTES AND HARPS," upon the condition (amongst others) that
I, the said John Tench, my executors or administrators, by an instru-
¡ ment 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 seven calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said John Tench, 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 boing had to the accompanying Sheet of
Drawings, and to the letters and figures marked thereon, that is to
Boy:-
My Invention relates to an improvement in tuning keys, and consists
in the application of gear by which the motion of the pipe or socket of
the key that fits upon the wrest pins is so reduced or diminished that
it makes but one revolution for several made by the handle of the key.
By means of this improved key the operation of tuning the instrument
is greatly facilitated, perfect command over the wrest pins and the
necessary delicacy of movement being obtained.
In tuning a pianoforte with the ordinary tuning key or "hammer,”
it is a common practice to turn the wrest pins backwards and forwards
a number of times, until the string is brought to the exact tension
required, but with the improved key of my Invention this objectionable
practice is avoided, the power being so much increased that the string
may be at once brought to the proper tension.
According to my Invention, the pipe or socket, instead of being
formed on the end of the key spindle as usual, is made separate, and
geared therewith by a train of wheels, whereby the power transmitted
is multiplied at the expense of speed, the pipe or socket being caused to
rotate slower than the handle of the key, preferably in the ratio of one
revolution of the former to about three of the latter,

page_text: be protected by the herein-before in part recited Letters Patent is, the
combination with a tuning key of gear by which the pipe or socket
of the key is made to turn slower than the handle, as and for the
purpose described.
In witness whereof, I, the said John Tench, have hereunto set my
hand and seal, this Twentieth day of April, in the year of our
Lord One thousand eight hundred and seventy-six.