Year: 1888

page_text: I ALFRED GEORGE BROWNE of No. 13 Derringham Street, Hull, Pianoforte Tuner,
do hereby declare the nature of this invention and in what manner the same is to he
performed, to be particularly described and ascertained in and by the following
statement:-
Hitherto in the construction of the internal mechanism of Pianofortes, the leverage
of the keys and of the jacks or hoppers is constant, with the touch being at all times
uniform, this is a disadvantage inasmuch as it requires some knowledge of or
acquaintance with an instrument before the instrumentalist is enabled to produce that
expression and life which is so necessary for the proper interpretation of the com-
position to be performed. My Invention has for its object therefore to overcome this
disadvantage, by the adoption of means for varying the leverage of the balance rail,
keys and jacks or hoppers to meet the requirements of a light or heavy touch.
In order that my Invention may be the better understood I have appended the
accompanying two sheets of drawings in which Figure 1 represents a portion of
the key-frame of a pianoforte, and Figure 2 is the underside of one end of a movable
balance rail. Figure 3 shows a plan of a pianoforte key having the improvements
according to my Invention adapted thereto. Figures 4 and 5 are respectively plans
of upper and, lower key pin plates. Figure 6 is a sectional elevational view of a key,
having the regulating key pin plates and regulating lever key block secured in
position. Figure 7 is an elevational view of a check action lever as hitherto ordinarily
made. Figure 8 is a similar view of an extended non regulating check action lever,
showing the altered position of the jack or hopper relatively to the rider block or
projection, and Figure 9 is a similar view of a check action lever with regulating jack
plate adapted thereto. Figure 10 is a sectional view of a regulating lever rail, with
action standard attached thereto, and Figure 11 is a sectional view of a non-regulating
lever rail and standard made in one piece.
Under the first head or feature of my Invention I perforate the stiles A of the key
frame of a Pianoforte, which may be of wood or metal, or of wood and metal
combined-with longitudinal slots a, a, within which the screws or equivalents b. 61 61 6111
of the balance rail Bare-when loosened-free to move. Between the screws b bl
and are two set-off screws ce¹ which, projecting beyond the under surface of

page_text: the balance rail B, rest upon the space between the slots a a of the stile aforesaid, a
distance determined by the depth of touch required; said balance rail B being secured
to the stiles A by means of the screws
above referred to; thus, by simply
loosening. the set-off screws c c the balance rail B may be shifted backwards or
forwards without necessitating the removal of the key-frame.
In order to allow for the different positions of the balance rail upon the key frame,
I perforate.the key C Figure 3 with a longitudinal slot d, over and under which, are
adapted the regulating balance key pin plates D, E, Figures 4 and 5, each having
corresponding longitudinal slots e e el et formed therein for the insertion of the
screws or equivalents ffff In the centre of the upper pin plate D is an oblong
hole or slot g and in the centre of the lower pin plate E is a circular counter sunk
hole g through which holes g, gl, passes the lever pin secured to the balance rail B.
The two pin-plates D, E above described, are secured by screws. or equivalent means
to two posts h, by which means the two pin-plates aforesaid may be simultaneously
moved along the key over the slot d the distance required by the alteration effected in
the position of the balance rail B, the pin-plates D. E being secured in the desired
position by tightening the screws fff" fill. In order to further increase and
decrease the leverage of the lever key C, I adapt to the rear end thereof a loose lever.
key block F, having a longitudinal slot i formed therein in which is inserted a screw j
to allow of said key block being moved forwards and backwards and secured in the
desired position, a set off screw being employed to regulate the height of the rear
end of said lever key block F.
The second head or feature of my Invention relates to the adoption of similar means
of regulating the leverage of the check action lever and jack or hopper. At Figure 7
is illustrated a check action lever G of the ordinary type in which it will be seen that
the rider block or projection is slightly in advance of the jack or hopper H, to which
the leverage of the lever key would be adjusted, but, in the event of the balance
rail B being moved forward, the power required to actuate the hammer would be
proportionately increased, to compensate for which, 1 may employ a nonregulating
check action G Figure 8 the rear end m of which is extended, and the rider block
or projection moved to a convenient position in rear of the jack or hopper H
according to the amount of leverage given to the balance rail, lever key and lever key
block. Instead however of extending the action lever in the manner above described,
I may employ a jack plate I Figure 9, having a longitudinal slot formed at each end
thereof, and secured by the screws n n'. To the rear end of said jack plate I is
pivoted the ordinary "flinge" K, for securing the check action lever G to the
hammer rail L Figures 10 and 11. When it is desired to alter the leverage of the
check action G, the screws n n¹, are loosened and the loose upper part N of the lever
is drawn forward to the desired distance and the screws again tightened.
Instead of rigidly fixing the hammer rail L and lever rail M. to the action standard,
I secure said rails thereto by means of a screw o two set-off screws pp¹ being
employed to adjust said rails L M to any desired angle, and thus further assisting in
the regulation of the check action. In Figure 10 the lever rail M and hammer rail L
are separate from and independent of each other, but I may under some circumstances
form a non-regulating lever rail and hanimer rail in one piece, or rigidly secure one
to the other as shown in Figure 11.
When increasing the leverage of the key the raising power thereof is diminished,
which is compensated for by bringing forward the jack plate of the check action, thus
increasing the raising power of the jack or hopper.
By the means above described according to my Invention I am enabled to ensure
to the key more or less leverage, to the extent of about three inches, which leverage is
utilised to render the touch light or heavy, as may be desired, by varying the positions
of the key pin plates, balance rail, key block, jack plate and lever rail, this power of
adjusting the leverage of the key is of special importance in a Pianoforte to which is
adapted an Octave coupler inasmuch as when the coupler is brought into action, it
is obvious that under ordinary conditions the touch would be heavier when the coupler
is brought into action than at other times.

page_text: The various adjustable devices above described for altering the leverage of the keys
and varying the touch which may be of wood or metal or of wood and metal combined,
may be employed in combination with each other, or they may, if found desirable, be
employed independently of each other.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is :-
:
First In a Pianoforte the adaptation to the key frame thereof of an adjustable
balance rail substantially as and for the purpose herein described.
:
Second The adaptation to the balanced lover keys of a Pianoforte of an adjustable
upper and lower key pin plate, substantially as and for the purpose herein described
and shown in the accompanying drawings.
Third In combination with the balanced lever keys of a Pianoforte the employment
therewith of adjustable key blocks substantially as and for the purpose herein set forth
and shown.
Fourth In a Pianoforte the employment therewith of a nou-regulating extended
check-action lever as identified in Figure 8 substantially as and for the purpose
herein set forth.
:
Fifth In combination with a check-action lever of a Pianoforte the adaptation
thereto of a regulating jack plate substantially as and for the purpose herein described
and shown.
Sixth In a Pianoforte the employment therewith of a combined Hammer rail and
nonregulating extended lever rail substantially as herein set forth and identified in
Figure 11.
Seventh In a Pianoforte the employment of a regulating lever rail in combination
with an independent hammer rail as identified at Figure 10 substantially as and for
the purpose herein set forth.
Eighth In a Pianoforte the combination of the several regulating devices substan-
tially as and for the purposes herein described and illustrated in the accompanying
drawings.