Improvements in and connected with Mechanism for Locking the Keys of Keyboard Musical Instruments.
Year: 1892

page_text: Date of Application, 23rd Feb., 1892-Accepted, 9th Apr., 1892
COMPLETE SPECIFICATION.
Improvements in and connected with Mechanism for Locking the
Keys of Keyboard Musical Instruments.
I, MAXIMILLIAN BROWNOLD, Musician, of 174 East 76th Street, New York,
in the County and State of New York, United States of America, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
This invention relates to keyboard musical instruments, such as pianos, organs
and the like, and its object is to provide means whereby all the keys, except those
corresponding to the key in which the music to be performed is written may be
locked and rendered mute and which also permits of using the instrument in the
usual manner without restriction as to the use of any of the keys whenever desired.
The invention consists principally of a locking device for each individual key.
The invention further consists of a mechanism for simultaneously locking the
corresponding keys of the several octaves; and the invention further consists of a
pedal action for simultaneously unlocking all the locking devices for the keys.
The invention also consists of certain parts and details and combinations of the
same, as will be fully described hereinafter and then pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
Specification, in which similar letters of reference indicate corresponding parts in
all the figures.
Figure 1 is a plan view of the attachment, as applied on the bass side of the
instrument and with part of the keys removed;
Figure 2 is a similar view of the same with part of the upper keys removed;
Figure 3 is a front elevation of the attachment:
Figure 4 is an enlarged transverse section of the attachment ;
Figure 5 is a like view of the same.
and
The musical instrument on which the attachment is applied is provided with the
usual key-board frame A, on which are arranged the keys B in the usual manner,
the said keys being pivoted at B' and guided at or near their front ends on pins B³
projecting upward from the key-board frame A. The rear ends of the keys B are
connected in the usual manner with the action of the instrument.
Under the front end of each key B, is arranged a locking device for locking the
key in its normal raised position so as to prevent its being depressed by the
performer. Each locking device consists preferably of an arm C projecting upward
from a plate C, mounted to slide transversely on the key-board frame A, the said
plate being provided for this purpose with a transverse slot C², through which pass
screws or pins C³ and C, to laterally guide the plate C. Each of the plates Cis
pressed on by a spring D to hold the said plate in a normal position, as is plainly
shown in Figures 4 and 5, the upper end of the arm C being then opposed to the
under side of the respective key, so as to prevent the latter from being depressed or
played on.
When the plate C is shifted laterally, then the upper end of the arm C is
adapted to register with an opening or recess B³ formed in the under side of the
respective key. When the arm C is in this position, the key B can be depressed
or played in the usual inanner, the arm C then having unlocked the key B.
Each plate C is connected with one end of a rope or string E passing over a
pulley F, mounted to turn on a suitable stud supported from the key-board frame A.
The rope or cord E extends transversely between the plate C' and the pulley F,
and then, after passing over the latter, exten is longitudinally and connects with a

page_text: bar G mounted to slide longitudinally in suitable bearings formed or secured on
the top of the key-board frame A. The corresponding keys of each octave have
their locking devices connected with the same bar G so that the several locking
devices of the corresponding key in the several octaves are acted on simultaneously
when the corresponding bar G is moved longitudinally, as hereinafter more fully
described.
Each of the bars G is formed on one side with a lug or projection G' adapted
to be engaged by an arm H' secured on the inner end of a shaft H extending
transversely and mounted to turn in suitable bearings arranged in the key-board
frame A. The front ends of the shafts H are provided with knobs or finger
pieces H2 located within convenient reach of the performer so as to be turned to
Each finger
actuate the locking devices as hereinafter more fully described.
piece H2 is marked with the name of the key it represents, as is plainly indicated
in Figure 3, in which the twelve finger pieces represent the twelve tones of each
octave.
When the several parts are in the position shown in Figures 4 and 5, the keys
are in a locked position and cannot be pressed or played on by the performer ;
now, when it is desired to unlock the corresponding keys of the several octaves
the corresponding knob or finger piece H2, bearing the name of that key, is
turned, so that the shaft H is rotated and its arm H₁ presses on the corresponding
lug G of the respective bar G with which the several locking devices for the
desired keys are connected. The longitudinal shifting of the respective bar G
causes a pull on the several cords or ropes E, which latter cause a transverse sliding
of the respective plate C³, so that the corresponding arms Care brought in register
with the openings or recesses B³ of the desired keys B. The latter as previously
stated, can then be depressed or played by the performer in the usual manner.
the performer, for instance, desires to play a piece of music written in C major,
he turns the finger pieces H2 marked C, D, E, F, G, A and B, whereby all the
corresponding keys in the several octaves are unlocked and can be played upon.
The other keys representing all the flats and sharps, remain locked by the
respective locking devices.
If
Now, if in playing the performer should touch one of the locked keys, it would
remain mute, as it cannot be depressed and consequently the performer will at
once notice that he has touched the wrong key. When the piece of music is
finished and the operator desires to again lock all the keys he turns the finger
piece H2 in the opposite direction to the former position to permit the spring D to
return the plate C, arm C, cords or ropes E, and bars G to their previous position.
In order to enable the performer to make use of all the keys whenever he
desires to do so, the following device is provided, a pedal action being introduced
for accomplishing the desired result :-
On the several bars G at or near their middle, are secured lugs G² or G³,
according to the direction in which the bars move, said lugs being adapted to be
engaged by plates or arms I¹ and 12 respectively, secured on a transversely
extending shaft I and extending in opposite directions therefrom. The
shaft I is mounted to turn in suitable bearings in the key-board frame A, as is
plainly shown in Figure 5, the rear end of the said shaft being provided with a
longitudinally extending arm J engaged, at its under side, by an arm K pivoted or
hinged at K to the key-board frame A. The under side of this arm K is adapted
to be engaged by a rod L, extending vertically and connected with a pedal N,
adapted to be actuated in the usual manner by the performer's foot. Thus, when
the pedal N is pressed, the rod L is lifted and presses on the arm K, which thus
swings upward and acts on the arm J, so as to turn the shaft I. The arms I and I'
of the latter. standing in opposite directions, act on the several lugs G² and G³
respectively, and thus shift the bars G longitudinally, to unlock the several keys B
simultaneously as by turning the knobs H, as above described.
As soon as the performer releases the pressure on the pedal N, the springs D
return the several plates C' to their normal positions, with the exception of those

page_text: bars G which had been previously moved in a locking position by the knobs H2 of
the shaft H turned according to the key in which the piece of music was written.
It will be seen that this key-board attachment is very useful for beginners who
have to practise in a certain key, as only those keys of the key-board are unlocked
which belong to their key. In case the pupil touches the wrong key, no sound
comes from the instrument, as the said key is not depressed and the action connected
with it is not set in motion. Hence, the performer knows instantly that he touched
the wrong key. Beginners are very liable to press two adjacent keys at the same
time with one finger. Now, if this happens, the wrongly touched key prevents
further downward movement of the finger, and consequently the correct or adjacent
key is not depressed or played. Great accuracy in touch can thus be acquired in a
very short time. The several knobs or finger pieces H2, when turned, unlock all
the keys in the key-board, so that the instrument can be played on in the usual
manner without interference by the attachment.
Again the several keys of the key-board can be unlocked simultaneously by the
use of the pedal action, as above described.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is,-
1. A key-board attachment, provided with a series of locking devices for the
keys, cach being adapted to engage a key to prevent the latter from being
manipulate, substantially as shown and described.
2. A key-board attachment, provided with a series of connected locking devices
for corresponding keys in the several octaves, the said locking devices being
arranged to lock the keys simultaneously to prevent them from being manipulated,
substantially as shown and described.
3. A key-board attachment, provided with a series of locking devices for the
keys, and a pedal action connected with the said locking devices to engage the
latter with the keys to prevent the latter from being manipulated, substantially as
shown and described.
4. A key-board attachment, comprising sets of locking devices for the keys, each
set connecting with the corresponding keys in the several octaves, and a mechanism
for each set of locking devices to move the same in engagement with their keys to
prevent the latter from being manipulated, substantially as shown and described.
5. A key-board attachment, comprising a locking device for each key, longi-
tudinal sliding bars for actuating the said locking device to lock or unlock keys,
and means, substantially as described, for controlling the movement of the said
longitudinal bars, as set forth.
6. A key-board attachment, comprising a locking device for each key and longi-
tudinal sliding bars for actuating the said locking devices to lock and unlock the
keys, each bar being connected with such of said locking devices as belong to
corresponding keys in the several octaves, substantially as shown and described.
7. A key-board attachment, comprising a locking device for each key, longi-
tudinally sliding bars for actuating the said locking device, and a pedal action for
simultaneously actuating the said bars to actuate the said locking devices to unlock
all the keys in the instrument, substantially as shown and described.
8. In a key-board attachment, the combination with an arm mounted to slide and
adapted to fock or unlock the free ends of the keys, of a cord or rope connected
with the said arm, and a bar mounted to slide longitudinally and connected with
the said rope or cord, substantially as shown and described.
9. In a key-board attachment, the combination with an arm mounted to slide and
adapted to lock or unlock the free ends of the keys, of a cord or rope connected with
the said arm, a bar mounted to slide longitudinally and connected with the said
rope or cord, and a pulley over which passes the said rope or cord, substantially as
shown and described.
10. In a key-board attachment, the combination with a key formed with a recess

page_text: in its under side, of an arm mounted to slide and adapted to engage the under side
of the said key, to prevent the latter from being played or to register with the said
recess to permit of depressing the key, substantially as shown and described.
11. In a key-board attachment, the combination with a plate mounted to slide
transversely and formed with an arm adapted to lock or unlock a key, of a rope or
cord connected with the said plate, a bar mounted to slide longitudinally and
connected with the said rope, and a shaft for actuating the said bar to move the
same longitudinally, substantially as shown and described.
12. In a key-board attachment, the combination with a plate mounted to slide
transversely and formed with an arm adapted to lock or unlock a key, of a rope or
cord connected with the said plate, a bar mounted to slide longitudinally and
connected with the said rope, a shaft for actuating the said bar to move the same
longitudinally, and a spring pressing on the said plate to return the same to a
normal position, substantially as shown and described.
13. In a key-board attachment, the combination with a plate mounted to slide
transversely and formed with an arm adapted to lock or unlock a key, of a rope or
cord connected with the said plate, a bar mounted to slide longitudinally and
connected with the said rope, a shaft for actuating the said bar to move the same
longitudinally, and a finger piece or knob held on the said shaft for turning the
same and indicating the corresponding keys, substantially as shown and described.
14. In a key-board attachment, the combination with an arm and a spring pressed
plate carrying the said arm, of a cord or rope connected with the said plate and
passing over a pulley, a longitudinally extending bar mounted to slide and connected
with the said rope, a lug on the said bar, an arm adapted to engage the said lug,
and a shaft carrying the said arm and formed with a finger piece indicating the
respective key to be locked or unlocked, substantially as shown and described.
15. In a key-board attachment, the combination with a pedal, of a rod adapted
to be actuated by the said pedal, a shaft mounted to turn and adapted to be
actuated by the said rod, arms extending from the said shaft in opposite directions,
and longitudinally sliding bars adapted to be actuated by the said shaft arms, the
said bars being connected with locking devices adapted to unlock the keys of the
key-board, substantially as shown and described.
16. In a key-board attachment, the combination with a pedal, of a rod adapted
to be actuated by the said pedal, a shaft mounted to turn and adapted to be
actuated by the said rod, arms extending from the said shaft in opposite directions,
longitudinally sliding bars adapted to be actuated by the said shaft arms, the said
bars being connected with locking devices adapted to unlock the keys of the key-
board, and intermediate mechanism for connecting the said rod with the said
shaft, substantially as shown and described.
Dated
Februa
91 1000
M. BROWNOLD,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.