[0001] The present invention relates to a piano key assembly and pianos having lever action
piano keys which displace variable mass hammers when depressed. The present invention
further relates to a method for adjusting the touch force required to depress a piano
key.
[0002] Numerous types of mechanisms have been employed in piano key action. In the typical
piano key action, when the front portion of a piano key is depressed, the rear portion
of the piano key actuates a piano hammer operating mechanism. The piano hammer operating
mechanism subsequently causes the felt-covered piano hammer to strike its respective
piano string. The touch force required to depress a piano key varies over the scale
due to differences in the weight of the piano hammers. The weight of the piano hammers
varies over the normally from about 10 to 12 grams at the bass end of the scale, to
about 3 to 4 grams at the treble end of the scale. Additionally, the force required
to actuate the hammers is affected by the difference in lever ratio arising from the
length of a black key being shorter than the length of the white key.
[0003] The variation in touch force makes it extremely difficult for anyone but a highly
experienced, professional pianist to maintain a uniform dynamic range as the piano
is played. Accordingly, it is desirable for the force required to depress a piano
key be uniform over the scale. Moreover, it is desirable to vary the touch of the
keys to suit individual preference and to be able to effect this variation or adjust
quickly and conveniently.
[0004] It is common practice to adjust the touch of key by placing permanent weights into
holes bored through the side of the piano keys. The weights are placed a distance
from the fulcrum so that all the keys use the same touch force. This method of adjusting
the piano key touch force is subject to multiple sources of error. Furhter, once the
weights are affixed, they cannot be adjusted anymore. Furthermore, through use, the
hammers will become worn, thus affecting the accuracy of the original weight adjustment.
[0005] The object of the present invention is to provide an adjustable piano key assembly,
a piano with such key assemblies, and a method for adjusting such piano key assemblies.
[0006] This purpose is fulfilled by a piano key assembly according to claim 1, a piano with
such key assemblies according to claim 13 and a method of adjusting the force required
to depress a piano key according to claim 14. Preferred configurations are object
of the subclaims. Further features and advantages are presented in the described embodiments.
[0007] It will be understood that the present invention is directed to a touch force adjustment
means wherein key weights are used to obtain a substantially equal static touch force
from key to key. The adjustment means of the present invention enables adjustment
of the touch force required to depress a piano key to accommodate pianists with varying
preferences and requirements. The ability to easily vary the piano key touch force
avoids the need to purchase multiple pianos for different pianist. Yet another object
of the present invention is to provide a touch force adjustment means which can inexpensively
be incorporated into new or existing pianos without substantial structural modifications.
[0008] The piano key assembly according to the present invention comprises an elongated
body having a first key end defining a playing surface and an opposite, second key
end for actuation of a piano hammer. A weighted member is provided, which is adjustably
attached to an adjustment region at the second key end.
[0009] Such a piano key assembly offers many advantages. One substantial advantageous is
that the touch force required to depress a piano key can easily be adjusted to specific
preferences of a user. Furthermore, the touch force can also be readjusted after a
long time of usage or after house moving.
[0010] Preferably, the adjustment region is a slot in the second key end of the elongated
body.
[0011] In advantageous configurations, the slot is elongated in shape with rounded corners.
[0012] In favored embodiments, the weighted member is adapted and constructed to fit into
the slot and wherein the weighted member has a shorter length than the slot.
[0013] It is also preferred that the weighted member is adjustably attached to the slot
by means of a security strip.
[0014] Preferably, the security strip is made at least in part of metal, plastic or wood.
In especially soft metal like iron or copper is suitable.
[0015] In other preferred configurations, the security strip comprises at least one, preferably
more than one and in particular four holes. These holes preferably correspond to at
least one, preferably more than one and in particular four holes provide in the elongated
body defining the adjustment region.
[0016] The security strip and the weighted member are in preferred embodiments fixable in
a specific position in the adjustment region by at least one screw.
[0017] Preferably, the security strip is received in a corresponding guide slot in the weighted
member.
[0018] In advantageous configurations, the weighted member is a lead block.
[0019] The piano key assembly according to any of the preceding claims, wherein the adjustment
region and the weighted member comprise an adjustment scale.
[0020] Preferably, the piano key assembly further comprises a rear bed plate with a nail
and/or a center bed plate with a balancing nail.
[0021] The piano according to the present inventions comprises a balance rail defining a
balance surface and at least one piano key assembly as described before. The at least
one piano key assembly is supported by said balance surface of said balance rail for
pivoting movement in response to application of force applied to the first key end
of the at least one piano key assembly.
[0022] The method of adjusting the force required to depress a piano key according to the
present invention comprises the steps of providing a balance rail defining a balance
surface and providing at least one piano key assembly as described before. The at
least one piano key assembly is supported by said balance surface of said balance
rail for pivoting movement in response to application of force applied to the first
key end of the at least one piano key assembly. The weighted member adjustably attached
to the adjustment region is displaced within said adjustment region to adjust the
touch force required to depress the piano key.
[0023] Preferably, at least one screw is used to fix the weighted member is a specific position.
[0024] In the drawings
- FIG. 1
- depicts an exploded side view of the piano key touch force adjustment system;
- FIG. 2a
- depicts the side view of piano key touch force adjustment system with the key weight
positioned to maximize required touch force;
- FIG. 2b
- depicts the side view of piano key touch force adjustment system with the key weight
positioned to minimize required touch force;
- FIG. 3a
- depicts the side view of the key weight;
- FIG. 3b
- depicts the perspective view of the key weight;
- FIG. 3c
- depicts the top view of the key weight;
- FIG. 4a
- depicts the top view of the strip; and
- FIG. 4b
- depicts the side view of the strip.
[0025] Referring to FIG. 1, which shows one embodiment of the piano key assembly 11 according
to the present invention. The piano key 6 is arranged on a balance rail 8 defining
a balance surface 27. The piano key 6 comprises an elongated body 12 having a first
key end 13 defining a playing surface 14 and an opposite, second key end 15 positioned
for actuation of a piano hammer. Mounted on the balance rail 8 is a fulcrum pin or
balance nail 5. The piano key 6 has a bore receiving the fulcrum pin 5. On the top
surface of the first key end 13, the piano key 6 is provided with a key covering 7
defining a playing surface 14, typically made of plastic. The center bed plate 4 is
attached to the top surface of the piano key 6. The rear bed plate 2 is attached to
the top surface of the second key end 15 of piano key 6, comprising a nail 1.
[0026] Within the portion of piano key 6 between the center bed plate 4 and rear bed plate
2 is the adjustment region 17 which in this case is a slot 18 in the elongated body
12. The slot 18 is a kind of elongated chamber 18, wherein this elongated chamber
8 preferably has rounded ends and is approximately 60 mm in length, 10,2 mm in width,
and 10,2 mm in height. Between the center bed plate 4 and rear bed plate 2 are four
holes 22 traversing the top surface of piano key 6 through to the adjustment region
17. In other embodiments another number of holes 22 can advantageous.
[0027] On the surface of piano key 6 exterior to the elongated chamber 18 are graduated
markings spaced preferably between 5 mm and 8 mm. This adjustment scale 26 is helpful
to adjust the force required to depress the piano key 6. The key weight 10 respectively
the weighted member 16 is elongated shaped as depicted in FIG 3. Preferably, the weighted
member 16 is approximately 26 mm in length, 10 mm in width, and 10 mm in height. On
the top surface of the weighted member 16 is a guide slot 24, approximately 2 mm in
depth and 4 mm in width as depicted in FIG 3b and FIG. 3c. The key weight 10 also
includes a graduated marking belonging to the adjustment scale 26. In this embodiment,
the weighted member 16 is a lead block 25.
[0028] A security strip 9 can be inserted into the guide slot 24, which in this embodiment
is located on the top surface of weighted member 16. The strip 9 is preferably made
of a soft metal 19 such as copper or iron. It can also advantageously be made of plastic
20 or wood 21.
[0029] The security strip 9 is in this embodiment approximately 3,5 mm in width, 1,5 mm
in thickness, and is approximately the length of the slot 18 as depicted in FIG 4a
and FIG 4b. The strip 9 may in some embodiments be fixedly attached to the weighted
member 16 such as by gluing or welding, or may be detachably secured to the weighted
member 16 such as with a clip, clasp, or velcro.
[0030] In this embodiment, however, the security strip 9 is loosely inserted into the guide
slot 24 and is only hold in position by the sidewalls of the guide slot 24 and the
top wall of the adjustment region 18. The weighted member 16 with the inserted security
strip 9 is pushed into the elongated chamber 18. Now it is possible to slide the weighted
member 16 along the security strip 9 in the adjustment region 17 to adjust the touch
force required to depress the piano key 6.
[0031] The security strip 9 contains a series of holes 22 as depicted in FIG 4b. In this
embodiment, the strip 9 has four holes 22. The outermost holes are approximately 6
mm from the end of the security strip 9. The spacing between the holes in the middle
of security strip 9 is approximately 12 mm. The weighted member 16 with strip 9 attached
is inserted into the elongated chamber 18 of piano key 6.
[0032] The four holes 22 in the strip 9 align with the four holes 23 in piano key 6. The
lateral movement of weighted member 16 is restricted by rotating screws 3 from the
top surface of piano key 6 into the corresponding holes 22 in security strip 9. The
piano key 6 touch force may be adjusted by loosening the screws 3, repositioning weighted
member 16 longitudinally within elongated chamber 18, and then rotating screws 3 from
the top surface of piano key 6 into the corresponding holes 22 in security strip 9.
Moving the weighted member 16 toward center bed plate 4 reduces piano key 6 touch
force. Moving the weighted member 16 toward rear bed plate 4 increases piano key 6
touch force.
[0033] Although the foregoing description of the present invention covers a presently preferred
embodiment, it will nevertheless be understood and appreciated by those familiar with
the art that changes, modifications and substitution of equivalent functioning elements
may be made in the described embodiment without departing from the spirit and scope
of this invention.
Reference numbers
[0034]
- 1
- nail
- 2
- rear bed plate
- 3
- screw
- 4
- center bed plate
- 5
- balance nail
- 6
- piano key
- 7
- key covering
- 8
- balance rail
- 9
- security strip
- 10
- key weight
- 11
- piano key assembly
- 12
- elongated body
- 13
- first key end
- 14
- playing surface
- 15
- second key end
- 16
- weighted member
- 17
- adjustment region
- 18
- slot, elongated chamber
- 19
- metal
- 20
- plastic
- 21
- wood
- 22
- hole
- 23
- hole
- 24
- guide slot
- 25
- lead block
- 26
- adjustment scale
- 27
- balance surface
1. A piano key assembly (11) with an elongated body (12) having a first key end (13)
defining a playing surface (14) and an opposite, second key end (15) for actuation
of a piano hammer, characterized in that
a weighted member (16) is provided, which is adjustably attached to an adjustment
region (17) at the second key end (15).
2. The piano key assembly (11) according to claim 1, wherein the adjustment region (17)
is a slot (18) in the second key end (15) of the elongated body (12).
3. The piano key assembly according (11) to claim 2, wherein the slot (18) is elongated
in shape with rounded corners.
4. The piano key assembly according (11) to any of claims 2-3, wherein the weighted member
(16) is adapted and constructed to fit into the slot (13) and wherein the weighted
member (16) has a shorter length than the slot (18).
5. The piano key assembly (11) according to any of claims 2-4, wherein the weighted member
(16) is adjustably attached to the slot (18) by means of a security strip (9).
6. The piano key assembly (11) according to claim 5, wherein the security strip (9) is
made at least in part of metal (19), plastic (20) or wood (21).
7. The piano key assembly (11) according to any of claims 5-6, wherein the security strip
(9) comprises at least one, preferably more than one and in particular four holes
(22) corresponding to at least one, preferably more than one and in particular four
holes (23) provide in the elongated body (12) defining the adjustment region (17).
8. The piano key assembly (11) according to any of claims 5-7, wherein the security strip
(9) and the weighted member (16) are fixable in a specific position in the adjustment
region (17) by at least one screw (3).
9. The piano key assembly (11) according to any of claims 5-8, wherein the security strip
(9) is received in a corresponding guide slot (24) in the weighted member (16).
10. The piano key assembly (11) according to any of the preceding claims, wherein the
weighted member (16) is a lead block (25).
11. The piano key assembly (11) according to any of the preceding claims, wherein the
adjustment region (17) and the weighted member (16) comprise an adjustment scale (26).
12. The piano key assembly (11) according to any of the preceding claims, further comprising
a rear bed plate (2) with a nail (1) and/or a center bed plate (4) with a balance
nail (5).
13. A piano comprising a balance rail (8) defining a balance surface (27) and at least
one piano key assembly (11) according to any of claims 1-12, wherein said at least
one piano key assembly (11) is supported by said balance surface (27) of said balance
rail (8) for pivoting movement in response to application of force applied to the
first key end (13) of the at least one piano key assembly (11).
14. A method of adjusting the force required to depress a piano key comprising the steps
of providing a balance rail (8) defining a balance surface (27) and providing at least
one piano key assembly (11) according to any of claims 1-12, wherein said at least
one piano key assembly (11) is supported by said balance surface (27) of said balance
rail (8) for pivoting movement in response to application of force applied to the
first key end (13) of the at least one piano key assembly (11), characterized in that the weighted member (16) adjustably attached to the adjustment region (17) is displaced
within said adjustment region (17) to adjust the force required to depress the piano
key (6).
15. The method of claim 14, wherein at least one screw (3) is used to fix the weighted
member (16) is a specific position.