IMPROVEMENTS IN APPARATUS FOR THE MECHANICAL PLAYING OF KEYBOARD INSTRUMENTS SUCH AS PIANOS AND ORGANS."
Year: 1882

page_text: LETTERS PATENT to Robert Hodges Bishop of Liverpool Road Islington in
the County of Middlesex and William Down of Vicars Road in the same
County, Mechanical Draughtsman, for an invention of "IMPROVEMENTS IN
APPARATUS FOR THE MECHANICAL PLAYING OF KEYBOARD INSTRUMENTS SUCH
AS PIANOS AND ORGANS."
PROVISIONAL SPECIFICATION left by the said Robert Hodges Bishop and
William Down at the Office of the Commissioners of Patents on the 5th May
1882.
ROBERT HODGES BISHOP, of Liverpool Road, Islington, in the County of
Middlesex, and WILLIAM DOWN of Vicars Road in the same County, Mechanical
Draughtsman, "IMPROVEMENTS IN APPARATUS FOR THE MECHANICAL PLAYING OF
KEYBOARD INSTRUMENTS SUCH AS PIANOS AND ORGANS."
This invention relates to improvements in apparatus for mechanically striking
the keys of pianos and such like instruments, the principal objects being to reduce
the cost and simplify the construction of the apparatus; to provide for the regu-
lation at will of the force with which the keys are struck thus producing the effect
of crescendo or diminuendo; and to facilitate the insertion and removal of
the metallic web or plate of perforated music by which the movements of the
strikers are governed:
Our improvements are more especially intended to be applied to apparatus
similar to that described in the specification of a Patent granted to Bristow Hunt
dated 22 November 1871 No 3158 in which a sheet of music is traversed through
the apparatus in a line at right angles to the keys of the keyboard instrument to
which it is applied.
Our improved apparatus consists essentially of a case or box mounted upon
adjustable standards and intended to be placed in front of and close to the key-
board of a Piano, or such like instrument, so that a series of horizontal strikers

page_text: will overlie the keys of the Piano and strike one or more of them at the proper
moment.
The strikers are hinged or pivotted at their rear end and are pressed upon by a
series of springs, preferably of flat steel, one for every striker, which springs are
adjustably mounted on a horizontal hinged bar to which a rocking motion may
be imparted at pleasure by the operator of the instrument by means of a lever
handle suitably placed, or by means of a treadle and suitable connections, or by a
roller or spindle on which are mounted suitable cams which may be caused to
press with more or less force upon angle pieces or lugs mounted on the said
horizontal hinged bar, thereby rocking the said bar and increasing or diminishing
the pressure of the springs on their respective strikers.
The music consists of a sheet or plate of perforated metal which is fed forward
by the rotation of one or more star wheels taking into equidistant slots in the
metallic plate; the plate being kept down in position by a bridge-piece, or guide,
suitably stiffened which is capable of vertical adjustment laterally and longitu-
dinally. The solid portions of the music serve to hold down the toothed ends of
a series of bell crank levers placed side by side within the recesses of a metallic
spacing comb, or guide-plate, and pivotted upon a common rod or spindle. The
lower end of each of these bell crank levers is connected by means of a rod or bar
with one arm of another bell crank lever which is pivotted to a horizontal bar
overlying the strikers, the other arm of each of these second bell crank levers
being slightly bent or cranked to allow of its overlapping its neighbour, and thus
economising space. A short pin is screwed into each of the strikers and connects
by a loop and pin with one arm of the bell crank lever immediately over it. Thus
when all the toothed ends of the first set of bell crank levers are held down by the
metallic music plate, all the second set of bell crank levers will be rocked and
the strikers be held up against the pressure of the springs, through the screwed
pins or their equivalent; but so soon as a perforation in the music coincides with
the toothed end of a lever, the toothed end will be free to rise and the spring
acting on its striker will cause the latter to forcibly depress its respective key and
a note will be sounded.
In order to provide for the ready insertion and removal of the perforated sheet
of metal we provide a spindle carrying a cam projection which may be made to
bear against the breasts of all the first set of bell crank levers by partially rotating
the spindle, thus forcibly withdrawing all the toothed ends of the said levers below
the level of the plate on which the music travels, and through a slot in which the
toothed ends project when their play is unrestricted.
As before stated means are provided for vertically adjusting the level of the
guide plate or bridge-piece beneath which the music is fed by the star wheels
above mentioned, so as to suit varying thicknesses of metal and ensure the complete
holding off of the strikers when they are not required to act.
We would here remark that we do not lay claim to any novelty in the principle
of holding down the levers which serve to restrain the movement of the spring
actuated strikers or plungers, by means of the unperforated portions of the metallic
sheet, or its equivalent, as this principle is well known, and has been described
and illustrated in the specification of a Patent granted to Carl Pieper (Paul Ehrlich)
on the 23rd October 1876.
Our improvements are directed rather to simplifying the construction and
fitting of the several levers and their connections whereby great accuracy of
register, and economy and speed of manufacture are attainable.
By this arrangement, great simplicity and strength of construction are attained,
and the passage for the music may be cleared by simply moving the cam roller,
or its equivalent, by which the toothed ends are withdrawn and held down.
As a modification of our arrangement for giving greater or less force to the
strikers, we propose when applying it to vertical strikers or plungers operated by
spiral springs, to employ a movable rail, or its equivalent, overlying the whole of
the said spiral springs the rail being depressed to a greater or less extent and the

page_text: springs cramped in a corresponding degree by the rotation or rocking of a bar
which carries two or inore arms overlying the said rail.
By this arrangement a player can while turning the handle whereby the music
is fed forwards, vary at will the force of the strikers, and produce temporarily or
permanently a Piano or forte effect, or a gradual change from one to the other.
The rocking of the bar may be effected in various ways as before indicated, such
as by using a treadle and suitable connections, or by a cam spindle acting on lugs
or angle pieces on the bar, or by a simple lever handle.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Hodges Bishop & William Down in the Great Seal
Patent Office on the 4th November 1882.
ROBERT HODGES BISHOP of Liverpool Road in the County of Middlesex and
WILLIAM DOWN of Vicars Road in the same County Mechanical Draughtsman.
IMPROVEMENTS IN APPARATUS FOR THE MECHANICAL PLAYING OF KEYBOARD
INSTRUMENTS, SUCH AS PIANOS AND ORGANS."
This Invention relates to improvements in apparatus for mechanically striking
the keys of pianos and such like instruments, the principal objects being to reduce
the cost and simplify the construction of the apparatus; to provide for the regu-
lation at will of the force with which the keys are struck, thus producing the effect
of crescendo or diminuendo, and to facilitate the insertion and removal of the
metallic web or plate of perforated music by which the movements of the strikers
are governed.
Our improvements are more especially intended to be applied to that class of
apparatus in which a sheet of music is traversed through the apparatus in a line
at right angles to the keys of the keyboard instrument to which it is applied.
The construction and arrangement of our improved apparatus will be readily
understood on reference to the accompanying Drawing in which Fig: 1 is a longi-
tudinal elevation partly in section, showing the case and its adjustable supports as
seen from the back. Fig: 2 is an end view of the same, also partly in section.―
Fig: 3 is a plan view of that end of the case at which the sheet of music is
inserted. Figures 4 and 5 are full size detail views shewing the method of con-
necting the strikers with the bell crank levers.-Fig: 6 is a view, partly in section
of the case with the music feeding mechanism arranged at the right hand; and
Fig: 7 shows the mode of uniting the sheets of music.
In these Figures A is the case or box mounted upon adjustable standards B and
intended to be placed in front of, and close to the keyboard of a piano C or such
like instrument, as shewn in Fig: 2, so that a series of horizontal strikers D will
overlie the keys E of the Piano, and strike one or more of them at the proper
moment.
The strikers D are each binged or pivotted at their rear end d and are each

page_text: pressed upon by a spring ƒ preferably of flat steel the said springs being adjustably
mounted on a horizontal hinged bar F to which a rocking motion may be imparted
at pleasure by the operator of the instrument by means of a lever handle G suitably
placed, or by means of a treadle and suitable connections operating a roller or
spindle G¹, on which are mounted suitable cams G². which may be caused to press
with more or less force upon angle pieces or lugs F. mounted on the said hori-
zontal hinged bar F, thereby rocking the said bar and increasing or diminishing
the pressure of the springs fon their respective strikers D.
The music H may consist of a sheet or plate of perforated metal but we
preferably employ a perforated sheet of "vulcanized fibre" which is fed forward
by the rotation of one or more star wheels taking into equidistant slots in the
metallic or other plate, the plate being kept down in position by a bridge-piece
or guide suitably stiffened which is capable of vertical adjustment laterally and
longitudinally but we preferably use a pair of smooth or finely fluted rollers I I'.
for feeding forward the music when made of the vulcanized fibre or thin metal
and we keep such music down in position over the ends of the levers K by a
third roller J mounted vertically over the slot through which the said lever ends
protrude.
This third roller J conveniently takes the place of the fixed bridge-piece above
referred to as it produces less friction and consequently less wear on the music
than the fixed bridge-piece.
This pressing roller J is grooved circumferentially at right angles to its axis,
and the plain parts between the said grooves correspond in position with the lines
of the music between the longitudinal rows of notes, and serve to hold down the
sheet of music against the upward pressure of the bell crank levers K.-When
using the finely fluted feeding rollers I I. it will not be necessary to slot or
perforate the edge of the music which if thin might be objectionably weakened by
such side perforations.
The uppermost of the feeding rollers I I', is journaled in adjustable spring
bearings so that an elastic nipping pressure may be obtained, in the manner well
understood, the elastic pressure being varied by means of a screw bolt which
presses down a plate of metal compressing a block of rubber or a metal spring
situate between it and the bearing block, which is flanged to partly embrace a
vertical guide.
The bell crank levers K are placed side by side within the recesses of a metallic
spacing comb or guide plate l and pivotted upon a common rod or spindle k*.
The lower end of each of these bell crank levers is connected by means of a rod or
bark with one arin of another bell crank lever K. which is pivotted to a hori-
zontal bar L overlying the strikers D, the other arm of each of these second bell
crank levers K'. being slightly bent or cranked as shewn in Fig: 4, to allow of its
A screwed
overlapping the neighbouring lever arm, and thus economizing space.
pin M is passed through each of the strikers D and connects by a loop M¹. and
pink with one arm of the bell crank lever K¹. situate immediately over it, as
shewn at Fig: 5. The screw pins M pass through the strikers D and spacing
collars or tubes N (which move freely through the bottom board O) and are
adjusted by means of the nuts m'. on their threaded ends m. By the help of
these screw pins M the horizontal strikers D may be accurately levelled, and an
equal touch upon all the keys E ensured.-The lower ends of the tubes N and
nuts m¹ are protected by a cover or guard attached to the bottom board O.
It will now be understood that when all the upper or toothed ends of the first
set of bell crank levers K are held down by the metallic music plate or sheet of
vulcanized fibre H all the second set of bell crank levers K¹ will be rocked and the
strikers D be held up against the pressure of the springs f through the screwed
pins M or their equivalent but so soon as a perforation in the music H coincides
with the upper or toothed end of one of the bell crank levers K the said toothed
end will be free to rise, and the spring f, acting on its striker D, will cause the
latter to forcibly depress its respective key E, and a note will be sounded.

page_text: In order to provide for the ready insertion and removal of the perforated sheet
of music H, whether made of metal or of fibre, we provide a spindle carrying a cam
projection P, which may be made to bear against the breasts of all the first set of
bell crank levers K, by partially rotating the spindle of the cam P, as clearly shewn
5 in Fig: 1, thus forcibly withdrawing all the toothed ends of the said levers below
the level of the plate on which the music travels and through a slot in which the
toothed ends of the levers project when their play is unrestricted. By means also
of this cam P the levers K can be prevented from simultaneously rising, when the
sheet of music has passed from under the roller or bridge-piece J, and allowing the
entire set of strikers D to crash down on the keys E.
As before stated means are provided for vertically adjusting the level of the
fixed guide plate or bridge-piece when that device is used for keeping down the
music as it is fed along by the star wheels, or finely fluted rollers I I¹ above
mentioned, so as to suit varying thicknesses of metal or fibre and ensure the
complete holding off of the strikers, during the passage of the music K, when they
are not required to act.
We would here remark that we do not lay claim to any novelty in the principle
of holding down the levers K, which serve to restrain the movement of the spring
actuated strikers or plungers D, by means of the solid unperforated portions of the
sheet Hof metal, or vulcanized fibre, or its equivalent, as this principle is well
known and has been previously described and illustrated.
Our improvements are directed rather to simplifying the construction and
arrangement of the several levers and their connections whereby great accuracy of
register and economy and speed of manufacture are attainable.
In Fig: 6 we have shown the feeding mechanism and the set of levers K
arranged to the right hand side of the apparatus, so that the player can stand
behind the centre of the apparatus and utilize the top of the case to rest the
unplayed music upon.
The position of the several parts is slightly altered, but their action remains the
same as before and will need no further explanation.
In Figures 7 we have shewn in plan and edge views the means for uniting the
sheets of music H, an operation which may be dispensed with when the apparatus
is constructed with the handle and its adjacent working parts at the right hand, as
shewn in Fig: 6.
On the end margins of one sheet small metal plates h with eyes in them are
rivetted, and to the corresponding margins of the following sheet are rivetted
small plates h. with hooks which engage with the eyes and unite the front and
rear edges of the Sheets.
By our construction and arrangement of parts, great simplicity and strength are
attained, and the passage for the music may be cleared by simply moving the cam
roller P or its equivalent by which the toothed ends are withdrawn and held down
clear of the music race.
As a modification of our arrangement for giving greater or less force to the
strikers, we propose, when applying it to vertical strikers or plungers operated by
spiral springs, to employ a movable rail or its equivalent overlying the whole of
the said spiral springs, the rail being depressed to a greater or less extent, and the
springs cramped in a corresponding degree by the rotation or rocking of a bar
which carries two or more arms overlying the said rail.
By either of these arrangements a player can, while turning the handle whereby
the sheet of music is fed forwards, vary at will the force of the strikers D, and
produce for a longer or shorter time a piano or forte effect or a gradual change
from one to the other.
The rocking of the bar F may be effected in various ways as before indicated
such as by using a treadle and suitable connections, or by a cam spindle acting on
lugs or angle pieces on the bar, or by a simple lever handle.
Having now set forth the nature of our Invention of "Improvements in apparatus
for the mechanical playing of keyboard instruments such as Pianos and Organs"

page_text: and having explained in what manner the same may be carried into practical
effect we wish it to be understood that We claim :-
First: In an apparatus for mechanically playing upon keyboard instruments in
which a sheet of perforated or indented music is caused to travel through the
apparatus by the rotation of a handle, substantially as above described, the
arrangement of horizontal rocking strikers D and springs f, pressing on the said
strikers and adjustable in the manner set forth, in combination with the sets of
bell crank levers K K' tension rods or wires k', and screwed pins M connected
with the strikers D as and for the purpose set forth.
Secondly. The use in combination with the set of bell crank levers K of a
suitably shaped cam P for holding the entire set of strikers out of action when
desired, to facilitate the introduction or withdrawal of the music.
Thirdly The means above described for varying the force exerted by the
strikers in an apparatus for mechanically playing upon keyboard instruments
whereby the effect of crescendo or diminuendo may be produced as desired during
the passage of the music.
In witness whereof I the said William Down have hereunto set my hand
and seal the fourth day of November in the year of our Lord One thousand
eight hundred and eighty two.