An Improvement in or applicable to the Actions of Pianofortes, Organs, and other Lever-keyed Instruments.
Year: 1890

page_text: Date of Application, 10th Jan., 1890
Complete Specification Left, 10th Oct., 1890-Accepted, 15th Nov., 1890
PROVISIONAL SPECIFICATION.
An Improvement in or applicable to the Actions of Pianofortes,
Organs, and other Lever-keyed Instruments.
I, WILLIAM DRAPER MOON, of 85 Newman Street, Oxford Street London, Dental
Student do hereby declare the nature of this invention to be as follows:-
This invention relates to a certain improvement in or applicable to the actions of
pianofortes, organs and other lever-keyed instruments, the especial object of the inven-
tion being to provide a key, which shall require the same amount of pressure to lower
it at whatever part it may be struck; and which shall retain the advantages of any
lever-action to which it may be applied.
The accompanying drawings are intended to illustrate the principle of the invention,
and not necessarily to represent the actual sizes and proportions of the parts, which
may vary with the dimensions and character of the instrument to which the improvement
is applied.
Fig. 1 represents a side elevation of a part of the lever with the improved key
adapted.
Fig. 2 represents an elevation of one end of the improved key.
This invention consists essentially in applying to the lever, which for this purpose
is made of uniform width in its whole length, a key 1 which is placed above the end
of the lever 2 and which is attached to it at one part only in such a way as to allow of
movement in a hinge-like manner.
This is effected by a piece of steel spring, which is made to fit into a slit 3 at about
one quarter of an inch from the end of the lever 2, and into a similar slit 4 in a con-
venient part of the base of the key 1. The steel spring is made of the width of the
lever, and of a length to suit the depth of the two slits aforesaid, so that when the
key 1, is affixed to the lever 2, the two shall be in contact.
The keys are made to resemble those of any lever keyed instrument, in their general
shape, but are made of a depth exceeding the depth of the levers by one half of an
inch for the white keys, and of a depth for the black keys, exceeding that for the white
keys by one quarter of an inch.
In one side of the key 1, at that end which is over the lever, a groove 5 is cut
out to a depth of three-sixteenths of an inch, which is bounded above by a horizontal
line at a distance of one quarter of an inch below the upper edge of the key 1, extending
from the end at 6 of the key to a point 7 over the slit 4, and bounded below by a line
extending from a point 8 about five-eighths of an inch below 6 to a point 9 about one
quarter of an inch below 7 and bounded at one end by a line between 7 and 9, and at
the other end open.
That part 10 of the base of the key 1 which is over the lever is bevelled from the
slit 4 to its end 11, the slope of the base of the key at that part corresponding to the
slope of the lever when depressed.
A suitable thin pad 12 may be placed between the base of the key 1 and the lever 2,
to prevent the possibility of the two surfaces producing a noise if brought into
contact.
In the centre of the end of the groove 5 in the side of the key 1, a slit 13 is
cut horizontally to a distance of about one quarter of an inch from the groove 5 for
the reception of a steel spring of twice the length of the slit 13.
A bar 14 of wood is then made of about three-sixteenths of an inch in width, and
about one-eighth of an inch in thickness, and this is made of a length exceeding by
one quarter of an inch the distance of the fulcrum of the lever from the top of the
lever 2 at the slit 3. One end of this bar 14 is slit across its narrowest dimension to
a depth of about one quarter of an inch, for the reception of the steel spring which is

page_text: projecting from the slit 13 in the key 1. At one quarter of an inch from the other
end of the bar 14 a hole is bored through it sideways.
The upright pin 15 at the fulcrum of the lever 2 is made to project above the top
of the lever sufficiently to allow a hole to be drilled through it transversely to the
length of the lever, at a height above the fulcrum of the lever equal to the height of
the slit 13 in the key 1, above the top of the lever 2. This hole has a metal pin 16
fitted into it, and secured in any suitable manner, and the pin 16 is made to project
from the side of the other pin 15 to a distance of one quarter of an inch.
The bar 14 is then fitted on to the pin 16 by its perforation in such a manner as to
allow of movement.
Any suitable means may be employed in constructing this joint.
That part of the base of the key 1 which is not over the lever 2 may be lightened by
the cutting away of a wedge-shaped piece.
All the parts if then fitted together, and secured in a suitable manner, and the
lever balanced, will be found to allow of the descent of key 1 and the lever 2 when
the key is struck.
The white keys may be swung at the middle of their bases, and if all the levers be
made of the same length, the black keys may be swung on their levers, at a part
corresponding and in a line with the attachments of the white keys to their levers.
In this manner all the keys will require the same pressure to lower them, and their
surfaces will remain horizontal in their descent, and every part of a key will respond
uniformly to the touch.
The materials to be used in construction, may vary, any wood of sufficient
hardness being suitable for the bar 14 and the key 1, and a metal being used for
the pin 16.
The application to pianofortes, organs and other lever-keyed instruments, of the
herein before described improvement will be found to be effective in attaining the objects
aforesaid.
Dated this 8th day of January 1800
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in or applicable to the Actions of Pianofortes,
Organs, and other Lever-keyed Instruments.
I, WILLIAM DRAPER MOON, of 85, Newman Street, Oxford Street, London, Dental
Student, 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, and accompanying drawing, that is to say :-
This invention relates to a certain improvement in or applicable to the actions of
pianofortes organs and other lever-keyed instruments, the especial object of the invention
being to provide a key, which shall require the same amount of pressure to lower it at
whatever part it may be struck, and which shall retain the advantages of any lever
action to which it may be applied.
The accompanying drawings (of which Figures 1, and 2, were filed with my Pro-
visional Specification) are intended to illustrate the principle of the invention and not
necessarily to represent the actual sizes and proportions of the parts, which may
vary with the dimensions and character of the instrument to which the improvement
is to be applied.
Figure 1 represents a side elevation of a part of the lever with the improved key
applied.
Figure 2 represents an elevation of one end of the improved key.
Figure 3 is a slightly modified form of arrangement.
The invention consists essentially in applying to the lever, which for this purpose is
made of uniform width in its whole length, a key 1 which is placed above the end of
the lever 2 and which is attached to it at one part only in such a way as to allow

page_text: of movement in a hinge-like manner. This is effected by a piece of suitable material
such as steel spring or vellum, which is made to fit into a slit 3 at about one quarter
of an inch from the end of the lever 2, and into a similar slit 4 in a convenient part
of the base of the key 1.
The steel spring or vellum is made of the width of the lever, and of a length to suit
the depth of the two slits aforesaid, so that when the key 1 is affixed to the lever 2,
the two shall be in contact.
The keys are made to resemble those of any lever-keyed instrument, in their general
shape, but are made of a depth exceeding the depth of the levers by about half an inch
for the white keys, and of a depth for the black keys exceeding that for the white
keys by a quarter of an inch.
In one side of the key 1 at that end which is over the lever a groove 5 is cut out to
a depth of three-sixteenths of an inch which is bounded above by a horizontal line at
a distance of a quarter of an inch below the upper edge of the key 1, extending from
the end at 6 of the key to a point 7 over the slit 4, and bounded below by a line
extending from a point 8 about five-eighths of an inch below 6 to a point 9 about
a quarter of an inch below 7 and bounded at one end by a line between 7 and 9, and
at the other end open.
That part 10 of the base of the key 1 which is over the lever is bevelled from the
slit 4 to its end 11, the slope of the base of the key at that part corresponding to
the slope of the lever when depressed.
A suitable thin pad 12 may be placed between the base of the key 1 and the
lever 2 to prevent the possibility of the two surfaces producing a noise if brought
into contact.
In the centre of the end of the groove 5 in the side of the key 1, a slit 13 is cut
horizontally to a distance of about a quarter of an inch from the groove 5 for the
reception of a piece of vellum, a steel spring, or other suitable flexible material of
twice the length of the slit 13. A bar 14 of wood is then made of about three-
sixteenths of an inch in width, and about one-eighth of an inch in thickness, and
this is made of a length exceeding by a quarter of an inch the distance of the fulcrum
of the lever from the top of the lever 2 at the slit 3. One end of this bar 14 is slit
across its narrowest dimension to a depth of about one quarter of an inch for the
reception of the vellum or steel spring which is projecting from the slit 13 in the
key 1. At one quarter of an inch from the other end of the bar 14 a hole is bored
through it sideways. The upright pin 15 at the fulcrum of the lever 2 is made to
project above the top of the lever sufficiently to allow a hole to be drilled through it
transversely to the length of the lever, at a height above the fulcrum of the lever equal to
the height of the slit 13 in the key 1, above the top of the lever 2. This hole has a metal
pin 16 fitted into it, and secured in any suitable manner and the pin 16 is made to
project from the side of the other pin 15 to a distance of one quarter of an inch.
The bar 14 is then fitted on to the pin 16 by its perforation in such a manner as to
allow of movement.
Any suitable means may be employed in constructing this joint. For instance, the
upper end of the pin 15 may be slotted so that the pin 16 can be dropped into it, a
wedge or strip of wood or other material being driven into the slot to retain the
pin 16 in its place. Or as shewn in Figure 3, the hole at the end of the bar 14
may be dropped over the pin, and kept down by a light spring 8. A washer 7 is fitted
upon the pin below the bar.
That part of the base of the key 1 which is not over the lever 2 may be lightened
by the cutting away of a wedge-shaped piece.
All the parts if then fitted together and secured in a suitable manner and the
lever balanced will be found to allow of the descent of the key 1, and the lever 2 when
the key is struck.
The white keys may be swung at the middle of their bases and if all the
levers be made of the same length the black keys may be swung on their levers at a
part corresponding and in a line with the attachments of the white keys to their
levers.

page_text: In this manner all the keys will require the same pressure to lower them and their
surfaces will remain horizontal in their descent and every part of a key will respond
uniformly to the touch.
The materials used in construction may vary, any wood of sufficient hardness being
suitable for the bar 14 and the key 1, and metal being used for the pin 16.
In the modified form of arrangement shewn in Figure 3, the key 1 is placed over
the lever 2 and is attached to the latter at 3 by a vellum or other flexible hinge of the
width of the lever. Beneath the inner end of the key 1 the bar 14 is arranged
and is attached to the key by a flexible joint at 5, similar to the one at 3, the outer
end of the bar 14 being fitted freely over the pin 7 and kept down in its place by a
spring as already described.
In the arrangements described the lever 2 and the bar 14 form a parallel motion,
and the key 1 being hinged to their outer ends is compelled to retain its horizontal
position when moving so that every part of its upper surface moves through an equal
vertical distance when it is depressed or raised, so that the same amount of pressure is
required to operate it at whatever point it may be struck.
The application to pianofortes organs and other lever-keyed instruments of the
herein before described improvement will be found to be effective in attaining the objects
aforesaid.
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. The method of arranging the keys of pianofortes, organs, and other lever-keyed
instruments, so that they retain their horizontal position when depressed or raised,
substantially as and for the purpose described.
2. The combination of the key 1, lever 2, and bar 14, connected and binged
together, substantially in the manner and for the purpose described and shewn in
Figure 1.
3. The combination of the key 1, lever 2, and bar 14, connected and hinged
together, substantially in the manner and for the purpose described and shewn in
Figure 3.
Dated this 10th day of October 1890