IMPROVEMENTS IN KEYBOARD INSTRUMENTS SUCH AS PIANOS AND ORGANS
Year: 1882

page_text: of
LETTERS PATENT to Arthur William Lovell Reddie of the Office for Patents
66 Chancery Lane in the County of Middlesex, Patent Agent for an Invention
"IMPROVEMENTS IN KEYBOARD INSTRUMENTS SUCH AS PIANOS AND
ORGANS" Communicated to him from abroad by Charles Theodore Virot
of Paris in the Republic of France
PROVISIONAL SPECIFICATION left by the said Arthur William Lovell
Reddie at the Office of the Commissioners of Patents on the 9th September
1882.
ARTHUR WILLiam Lovell REDDIE of the Office for Patents 66 Chancery Lane
in the County of Middlesex, Patent Agent "IMPROVEMENTS IN KEYBOARD
INSTRUMENTS SUCH AS PIANOS AND ORGANS." [Communicated to him from abroad
by Charles Theodore Virot of Paris in the Republic of France]
The objects of the present improvements are as follows:-
1. To facilitate the regulation or adjustment of keyboard instruments without
the necessity for removing the keys.
2. To obviate the effect of the shrinking of the wood of which the keys are made
upon the pivot and guide pins by reason of variations in temperature and climatic
influence.
3. To facilitate the work of making and mounting the keys, at the same time
rendering the work more exact.
To this end the improvements relate to the pivot pins which are of entirely
novel construction, and to the form and fitting of the mortises to receive the pivot
and guide pins, which mortises I make of cylindrical form and line with a
substance which will be able to resist the effects of climatic action upon the wood
of the keys.
In applying these improvements to the keyboard of a piano, for example, the
pivot pins and guide pins are inserted as usual in the balance bar and front rail
respectively underlying the row of keys, and the keys operate the hammers in the
usual manner,

page_text: The pivot pins of the keys, however, instead of being of the usual simple form,
as in ordinary keyboard instruments, consist of regulator or adjustable pins, which
are so formed as to screw into the balance rail,
The upper ends of these regulator pivot pins pass right through the keys, and
are formed with a rounded shoulder serving as the point of oscillation for the keys,
and with a squared upper end to receive a small key by which the height of the
key may be regulated by screwing the pivot pin in or out.
The mortises formed in the keys are of cylindrical form and are each fitted with
a lining or sleeve, also of cylindrical form, of bone, ivory, celluloid or equivalent
substance, protecting the pivot pin against the effects due to the expansion or
contraction of the wood of the key.
These sleeves are slotted to allow of the longitudinal rocking movement of the
keys, and are covered or enclosed at one end by a metal cap, having a hole through
its centre corresponding to the slot in the lining of ivory or equivalent material.
For the pivot-pin mortises this cap or ferrule is inserted in the top of the key, while
for the guide-pin mortises it is inserted in the underside thereof.
By these improvements the position of the point of support or of oscillation of
the keys of any sort of keyboard instrument, may be adjusted and the effect of
climatic influences on the play or contraction of the wooden keys upon the pins
will be obviated.
The ivory or other lining of the guide pin mortises is preferably secured against
expansion or contraction of the wood by a simple ferrule or band, instead of by a
Blotted metal cap.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Arthur William Lovell Reddie in the Great Seal Patent Office
on the 26th February 1883.
ARTHUR WILLIAM LOVELL REDDIE of the Office for Patents 66 Chancery Lane
in the County of Middlesex Patent Agent "IMPROVEMENTS IN KEYBOARD
INSTRUMENTS SUCH AS PIANOS AND ORGANS Being a communication to me from
Abroad by Charles Theodore Virot of Paris in the Republic of France.
The objects of the present improvements are as follows.
1. To facilitate the regulation or adjustment of keyboard instruments without
the necessity for removing the keys.
2. To obviate the effect of the closing of the wood of which the keys are made
upon the pivot and guide pins, by reason of variations in temperature and climatic
influence
3. To facilitate the work of making and mounting the keys, at the same time
rendering the work more exact
To this end the improvements relate to the pivot pins which are of entirely
novel construction, and to the form and fitting of the mortises to receive the pivot
and guide pins which mortises I make of cylindrical form and line with a
substance which will be able to resist the effects of climatic action upon the wood
of the keys.
In the accompanying drawing fig: 1 is a transverse vertical section of a key-
board fitted according to this improved system.
Fig: 2 is a corresponding plan view of one of the keys. Figures 3. 4 and 5 are
detail views of the new pivot pins and the fittings connected therewith.
The keys T which are levers of the first order have their fulcrum on the balance
bar B. The extremity A is that which receives the touch of the finger and is
guided in its rocking movement by the guide pins a of ordinary construction fixed
in the front rail D. The end C which is heavier than A rests on the back rail D'
and is that which sets the "action" in movement.
The pivot pins of the keys however instead of being of the usual simple form as
in ordinary keyboard instruments, consist of regulator or adjustable pins R (Figures
1. 2 and 3) which are so formed as to screw into the balance rail B.
The upper ends of these regulator pivot pins one of which is shewn separately in
fig: 3 pass right through the keys, and the said pins are each formed with a round
shoulder e serving as the point of oscillation for the keys, and with a squared upper
end to receive a small key by which the pivot pin can be screwed in or out, and the
height of the key be most exactly and easily regulated.
The mortises in the keys to receive the pivot pins R and the guide pins a are
formed by boring a cylindrical hole in the key as indicated in the Drawing, and
within the cylindrical hole thus formed a plug or lining of bone, ivory, celluloid or
equivalent substance is inserted.-This cylindrical plug is slotted or cut through
for a great portion of its depth as shown in fig: 5, and the uncut portion is drilled
centrally with a hole the size of the stem of the pin R as shewn in figs 4.
The saw cut or slot allows of the free tipping action of the key upon the round
shoulder of the adjustable screw pivot pin R, the stem of which passes through
the central hole in the bottom of the plug of bone or equivalent substance.
The upper ends of the plug or lining of bone or ivory are then pressed slightly
towards each other within the cylindrical mortise, and a metallic cap b is put over
them and inserted tightly within the upper end of the mortise as shown in
figs 4.-A ring c may also be used to enclose the forked ends of the slotted plug
as shewn in figures 5

page_text: It will be seen that for the pivot pins R the cap 6 or ring c is inserted in the
upper end of the mortise, while for the guide pins a the metallic cap or ring is
inserted at the lower end of the said mortise.
The top of the metal cap piece b has a hole across it of a form corresponding to
the slot or cut in the plug.
These metallic caps or rings effectually prevent the swelling of the wood from
closing upon and gripping the pivot or guide pins, and thus avoid all chance of
creaking noises arising from this cause.
By the use of the improved pivot pins R. the keys may be quickly and accurately
levelled, without the necessity for removing any of the keys, by simply raising
or lowering their centres of oscillation-which can be done by screwing in or out
the said pins.
Having now set forth the nature of the said Invention of "Improvements in
keyboard instruments such as pianos and organs" as communicated to me by my
Foreign Correspondent, and having explained in what manner the same may be
carried into practical effect I wish it to be understood that I claim
First Pivotting the keys in Pianofortes and other key-board instruments in
the manner above described, whereby the raising or lowering of the centres of
oscillation of the individual keys may be effected without removing the keys from
their place.
Secondly-The combination with the balance rail B and keys T of the screw pin R,
having a round shoulder e formed thereon, and a square or other suitably formed
head as and for the purpose set forth.
Thirdly Fitting the mortises in the keys of pianos and other keyboard instru-
ments with slotted plugs or linings made from bone, celluloid, ivory or equivalent
material, in combination with strengthening caps or rings of metal in the manner
described with reference to the drawing, and for the purpose set forth.
In witness whereof I the said Arthur William Lovell Reddie have hereunto
set my hand and seal the twentyfourth day of February in the year of our
Lord One thousand eight hundred and eighty three.
ADTHIID III DEDDIN