Ema Improvements in Transposing Keyboards for Musical Instruments.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Ema
Improvements in Transposing Keyboards for Musical Instruments.
I, JAMES MERRILL GILBERT of Putney in the County of Windham and State
of Vermont, United States of America, Mechanic 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 :-
The object of my invention is to provide a transposing keyboard for a musical
instrument which may be quickly and easily adjusted so that while music, as
written, is being played it will in reality be produced in a higher or lower key, as
the case may be.
To this end, my invention consists in certain features of construction and com-
binations of parts, which will be hereinafter fully described 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 broken perspective view, partly in section, of the ordinary keys of
a piano, and the transposing keyboard mounted above the keys;
Figure 2 is a transverse section, on the line 2-2 of Figure 1:
Figure 3 is a detail sectional plan of the hand wheel for adjusting the
keyboard, and the spring catch for locking the hand wheel, the view being taken
on the line 3-3 of Figure 2;
Figure 4 is a broken plan, showing the keyboard frame in position in the piano
case, but with the finger keys removed;
Figure 5 is a broken sectional view on the line 5-5 of Figure 2;
Figure 6 is a broken sèctional view, showing the application of the transposing
keyboard to an organ; and
Figure 7 is a plan of the same, with the finger keys removed.
The piano case A, is of the usual construction, having at each end of the
keyboard the horizontal boards a, which are arranged so that the keyboard may
slide beneath them, and the case has the usual horizontal partition B, to a cross
bar B1, of which are pivoted the keys C, which are of the usual construction, except
that they are not provided with finger keys. The keys C are guided by pins c,
which extend upward from a cross bar C, in the usual manner, so as to enter slots
in the front ends of the keys, and the front ends of the keys have thin pieces of felt
or other suitable material upon their upper sides to prevent noise when the upper
keys strike upon them.
The keys of the transposing keyboard are mounted in a rectangular frame which
slides in the piano case, and which consists of the parallel front and rear rails D,
and the connecting end rails D¹, the end rails D' being widened at their front ends,
as shown at d, in Figures 2 and 5, so that the rear rail D is higher than the front
rail of the frame, and consequently extends above the rear ends of the keys in the
transposing keyboard.
A cross bar E, extends through the piano case, behind the rear rail D of the
keyboard frame, and on the upper and lower sides of the cross bar are forwardly-
extending clips E', which are bent over at their forward ends, as shown at c, so as
to fit upon corresponding shoulders of the rear rail D, and thus guide the keyboard
frame.
Located in the case, at each side of the main keys C, are short strips F, which
serve as guides and prevent the upper keys, or the keys of the keyboard, from
dropping down when they are moved from above the lower keys. The upper
keys G, which form the finger keys of the transposing keyboard are pivoted to the

page_text: rear rail D of the rectangular frame by means of the blocks H, there being a block
for each key, and the blocks are attached firmly to the rear rail of the
keyboard frame, and have depending tongues h, at, their lower ends which
project into slots in the keys G, and. to which the keys are pivoted by
suitable pins. On the rear ends of the keys G, and on the upper sides are
weights J, which are screwed to the keys, and by properly adjusting the weights
the keys may be nicely balanced.
The front rail D of the keyboard frame lies flatwise upon the partition B, and
extending along the upper surface of the rail and on opposite sides thereof, are the
parallel bars K and K', the front bar K having upon its upper edge guide pins k,
which extend into slots in the longer or natural keys G, and the rear bar K¹
has similar pins extending into corresponding slots in the shorter keys of the
keyboard; and while I have shown the bars K and K' as separate from the
front rail D, it is obvious that the rail and bars may, if desired, be made in one
piece.
A transverse bar L, extends between the parallel bars K and K', the bar being
pivoted to the front bar K by means of the links L', which are located near the
ends of the bar L, and it will thus be seen that the bar may be moved vertically
but cannot be displaced. The bar L rests normally upon the stop blocks L².
As shown in Figure 1, the front rail D of the keyboard frame is slotted longi-
tudinally, the slot aligning with the transverse bar L, and fixed in one side of the
slot is a rack M, which meshes with a pinion N, the pinion being fixed to a
shaft N, which extends downwardly through the partition B which forms the
bottom of that part of the case which is immediately beneath the keyboard. The
shaft N turns in a suitable sleeve », and fixed to the lower end of the shaft, is a
hand wheel N, which has perforations ', extending vertically through it and
arranged at regular intervals therein.
A flat spring O, is fixed to the under side of the partition B, at one end, and the
free end of the spring presses upon the upper side of the hand wheel N³, and is
provided with a depending stud o, which enters one of the perforations ¹ of the
hand wheel and thus prevents the wheel from being turned, and if the hand wheel
is locked, it will be seen that on account of its connection with the keyboard frame
the keyboard will be also locked so that it cannot be accidentally moved. A
pin P, extends vertically through the partition B and through a suitable guide
block P, on the upper side of the partition, the upper end of the pin impinging on
the lower side of the transverse bar L, and the lower end of the più impinging upon
the upper side of the spring O.
It will thus be seen that when the spring O is raised to unlock the hand wheel,
the pin will also raise the transverse bar L, and that, pressing against the lower
sides of the keys G will raise these keys from contact with the keys C, so that the
keyboard frame may be moved to the right or left as desired.
To shift the keyboard, the operator raises the spring O, thus unlocking the hand
wheel and raising the keys, as shown, and the hand wheel is then turned to the
right or left as desired, thus causing the pinion N to actuate the rack M and the
keyboard frame, and upon releasing the spring, the stud o immediately enters one
of the perforations of the hand wheel, and locks the hand wheel and the keyboard
as above described.
In Figures 6 and 7, I have shown the keyboard as applied to an organ, and in
these figures the device is substantially the same, but only one set of keys is
necessary. The organ case A', has the usual horizontal partition B2, and on the
upper side of the partition, near the ends are cross bars Q, upon which is mounted
a rectangular frame D, the frame being adapted to slide thereon, and upon the
front and rear sides of the frame are produced flanges d', which are overlapped by
the angular clips y, attached to the front and rear ends of the cross bars Q, and the
clips thus serve as guides for the frame. The frame D has keys G", pivoted
therein, the keys being of the usual construction, except that they are slotted
horizontally on their rear ends, as shown at y, and the keys are pivoted to the frame

page_text: at their rear ends by means of the pins gl. An angular clip R, is fixed to the rear
rail of the frame D and enters the slots in the rear ends of the keys, thus serving as
a guide and preventing the displacement of the keys.
Beneath the frame D is a transverse bar S, and pins S', extend vertically
through the bar in alignment with the keys G, the upper ends of the pins
impinging on the lower edges of the keys, and the lower ends of the pins impinging
upon the levers T, which operate the reed mechanism of the organ in the usual
manner. The frame is also provided with a transverse bar L, for raising the keys
in the manner already described, with suitable guide pins k, which enter slots in
the keys, and with the rack and pinion movement already described for moving the
frame. The organ case has rods t, fixed to the inner sides at each end so as to
project over the frame D, and the rods serve to prevent the keys from falling down
when they are moved to one side of the reed lever T.
It will be seen that when the keys G of the piano or the keys G of the organ
are moved to one side, they will be moved also beyond the piano keys C or the
organ levers T, and in order that the instruments may always be played up to their
full capacity, they are provided with extra finger keys, there being enough extra
keys so that the piano keys C and the organ levers T will all be constantly covered.
The instruments are played in the usual manner, and when the keys G of the piano
are depressed, they operate upon the keys C, causing them to operate the piano
hammers in the usual manner, and when the organ keys Ga are depressed, they
cause the pins S₁ to operate upon the levers T, so that anyone who can play an
instrument of the ordinary construction can play upon it when provided with the
transposing keyboard.
To facilitate the adjustment of the transposing keyboard, that part of the case of
the piano or organ which is immediately behind the finger keys commonly called
the name board is lettered, as shown in Figure 1, the letters corresponding to the
permanent keys of the instrument, and being directly above the same, and the
Ckeys of the transposing keyboard are marked preferably with an arrow, and
when the arrows are opposite the letters G on the case, the instrument will be in
its normal position, or at concert pitch, and the change made by shifting the key-
board will be indicated by the position of the arrows in relation to the letters on
the case.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. A transposing keyboard, comprising a movable frame having finger keys
pivoted therein, a rack and pinion movement for actuating the frame, and a locking
device for the pinion, substantially as described.
2. A transposing keyboard, comprising a movable frame, a series of finger keys
pivoted in the frame, said keys having guide pins, as shown, a vertically-movable
bar extending transversely beneath the keys, means for raising the bar, a rack and
pinion movement for operating the frame, and a locking device for the pinion,
substantially as described.
3. A transposing keyboard, comprising a laterally-movable frame having a series
of keys pivoted therein, said keys having suitable guide pins as shown, a guide for
the frame, a rack and pinion movement for operating the frame, and a locking device
for the pinion, substantially as described.
4. The combination, with the keys of a transposing keyboard and the frame in
which they are pivoted, of a bar pivoted transversely below the keys, a rack on the
frame, a pinion engaging the rack, and a lock for the pinion, which lock is also in
engagement with the pivoted bar, substantially as described.
5. A transposing keyboard, comprising a frame, a series of keys pivoted in the
frame and provided with suitable guide pins, a transverse bar extending beneath the
front ends of the keys, a rack and pinion movement for operating the frame, a
pinion shaft having a perforated handle located beneath the case of the instrument,

page_text: a spring having one end fixed to the instrument beneath the keyboard and having
its free end provided with a stud adapted to enter the perforations of the pinion
handle, and a pin extending through the instrument case, having its upper end
impinging on the transverse bar and its lower end on the spring, substantially as
described.
6. The combination, with a piano, of a frame mounted above the piano keys and
having a series of finger keys pivoted therein, suitable guides for the frame and for
the keys, a vertically-movable bar extending transversely beneath the keys, said
bar having a link connection with the frame, as shown, a rack and pinion movement
for operating the frame, a pinion shaft having a perforated handle located beneath
the case of the instrument, a spring having one end fixed to the instrument case and
the free end provided with a stud to enter the perforations of the pinion handle,
and a pin extending vertically through the case, its upper end impinging on the
transverse bar and its lower end impinging on the spring, substantially as described.
7. In a transposing keyboard, the combination, of a movable frame, blocks fixed
to the rear rail of the frame and provided with depending tongues, and finger keys
having slots therein to receive the tongues, substantially as described.
8. In a transposing keyboard, the combination, of a movable frame, blocks fixed
to the rear rail of the frame and provided with depending tongues, and finger keys
having slots to receive the tongues, said keys being pivoted to the tongues and
having their rear ends provided with weights, substantially as described.
9. In a transposing keyboard, the combination, with a movable frame having finger
keys pivoted therein, of a cross bar extending above the keys, and clips fixed to
the cross bar and having their ends bent to embrace and guide the end rail of the
frame, substantially as described.
10. In a transposing keyboard, the combination, of a movable frame, a rack and
pinion movement for operating the frame, a perforated handle on the pinion shaft,
and a spring fixed to the instrument case and provided at its free end with a stud
adapted to enter the perforations of the pinion handle, substantially as described.
Dated this 3rd day of March 1851.
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ΔΥΟ 1001,
J. M. GILBERT.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.