JPH0544872Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a keyboard instrument in which the closing action of the keyboard lid is softened by a braking device.

(Prior art) As shown in FIG. 6A and B for keyboard instruments, arcuate grooves 2 centered on the opening/closing pin shaft 3 have been bored on both sides of the thick base end of the keyboard lid 1. , the arc-shaped wall surface is used as a cam surface, a leather material 2a is pasted on the surface, a mounting bracket 4 having an opening/closing pin shaft 3 is fixed to the inside position of the arc-shaped groove 2, and the pin shaft 3 is attached to the piano body. The keyboard cover 1 is rotatably held by engaging with the U-shaped recess 5a of the bearing fitting 5 fixed on the inner surface of the keyboard cover 1. The base end of a fishhook-shaped leaf spring 6 is attached to the rear end surface of the clapboard 7, and its curved free end is brought into pressure contact with the arcuate cam surface inside the arcuate groove 2 of the keyboard lid 1. , a device that suppresses the rotational energy when the keyboard lid 1 is closed from the open position is known from Utility Model Application No. 54-3135, and as shown in Fig. 7 A and B, a cylindrical case is used. 3′
a damper shaft 4' that is rotatably supported inside and has a gear 6' at its outer end; A rotary damper 2' consisting of a coil spring 5' is embedded in both sides of the rear end of the keyboard lid 1', while a stationary gear 7' that meshes with the gear 6' of the damper shaft 4' is embedded in the inner surface of the piano body P'. The coil spring 5' is wound up by the closing operation of the keyboard lid 1' from the open position via the gears 7' and 6', and the rapid rotation of the keyboard lid 1' is suppressed.
It is known from Japanese Patent Application Laid-Open No. 63-55592.

(Problem to be solved by the invention) By the way, in the former conventional keyboard instrument, the radius of curvature L of the cam surface of the arcuate groove 2 at the point where the free end of the leaf spring 6 comes into contact when the keyboard lid 1 is closed is , the radius of curvature is made larger than the radius of curvature of the point where the free end of the leaf spring 6 comes into contact when the keyboard lid 1 is opened and stands up, and the leaf spring 6 is deformed outward by the opening and closing operation of the keyboard lid 1;
The repulsive force of the spring 6 is used to brake the fall of the lid 1, but the amount of displacement X of the spring 6 using the cam surface provided on the keyboard lid is a few mm at most, and it is large. Therefore, we cannot expect much of a braking effect. Furthermore, it is difficult to process an arcuate groove with a cam surface of constant curvature.

In addition, in the latter case, it is necessary to machine a hole for embedding the rotary damper 2' in the thick base end of the keyboard lid 1', which is time-consuming and time-consuming.
There is a limit to the wall thickness of the base end of the keyboard lid due to space constraints such as the presence of clapboards under both sides of the base end, and the rotary damper installed there and the gear that operates it are limited. 6' and 7' cannot be made too large, and therefore the winding radius of the coil spring 5' wound around the damper shaft 4' becomes small.
In order to obtain a certain braking effect on the heavy keyboard lid 1', it is necessary to use a considerably strong coil spring 5'.
Disadvantages include clumsy operation, the need for gears, a large number of parts, and high cost.

Therefore, this idea allows for smooth opening and closing of the keyboard lid.
To provide a keyboard instrument that can be played smoothly, has a simple configuration, and has a large braking effect.

(Means for solving the problem) Based on the above-mentioned purpose, this invention is a keyboard lid consisting of a tongue-shaped second leaf spring, an S-shaped and elongated first spring, a stopper, and a friction plate. A keyboard instrument having a braking device, wherein the tongue-shaped second leaf spring is mounted on both upper sides of the rear end surface of the proximal end of the keyboard lid rotatably supported on the side plate of the instrument body through the base plate. The first leaf spring, which is S-shaped and elongated, has an inner end hinged to the upper edge of the base plate of the second leaf spring. The stopper is connected to the keyboard lid so that its free end extends rearward and upward within the instrument body, and the stopper is formed entirely or partially of a magnet, and the stopper is connected to the second stopper on both sides of the rear end surface of the base end of the keyboard lid.
The friction plate is attached under the leaf spring so that its protrusion length can be adjusted, and the friction plate is formed thicker toward the top, and is attached on the inner surface of the side plate along the rotation path of the tip of the second leaf spring. It is characterized by the fact that it is

(Operation) When the keyboard lid is rotated downward from the upright open position, the free end of the first leaf spring comes into contact with the instrument body, and the keyboard lid rotates while deforming the first leaf spring. After turning a certain angle from the standing position, the second
The leaf spring comes into pressure contact with the friction plate on the side of the instrument body and rubs against its surface, and as the lid subsequently rotates, the elastic force increases due to the large deformation of the first leaf spring, and the wall thickness of the plate increases. This change increases the frictional force of the second leaf spring, and these two forces suppress the falling movement of the keyboard lid.

(Embodiment) An embodiment of this invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 shows one side of the thick base end of the keyboard lid 11 viewed obliquely from the rear in an example in which this invention is applied to a grand piano. Attach the pin shaft 11a to the required position on the side surface of the keyboard (close to the inner plane of the keyboard lid).
This pin shaft 11a is connected to the side plate 2 of the piano body.
It is engaged with a U-shaped groove of a support fitting 21a attached to the inner surface of the support member 1 and is rotatably supported.

At the upper corners of both sides of the rear end surface (only one side is shown in the figure) of the base end of the keyboard lid 11, there is a short tongue-shaped groove whose tip part protrudes toward the side plate 21 of the piano body. 2 flat base plate portion 13 of leaf spring 13
a is fixed with a screw or the like. Further, on the upper edge of the base plate portion 13a of the second leaf spring 13, the inner end of the elongated first leaf spring 12 for braking whose side surface is bent into a substantially S-shape is attached to the winding formed in each spring. The parts 12b and 13b are connected in a hinge-like manner by a pin 14 inserted therein, and the first leaf spring 12 is rotatable in the vertical direction with respect to the keyboard lid 11. FIG. 1 shows this in a state in which it has been rotated upward.

Also, on both sides of the rear end surface of the thick base end of the keyboard lid 11, at a position below the base plate 13a of the second leaf spring 13,
A stopper 15 made entirely of magnets or with a magnet attached to its head is attached so that its protrusion length can be adjusted, while the tip of the second leaf spring 13 is attached to the pin shaft on the inner surface of the side plate 21 of the piano body. An arcuate friction plate 16 is mounted which is thicker toward the top so as to correspond to a rotation path that rotates about 11a.

FIG. 2A shows a state in which the keyboard lid 11 is opened 90 degrees upward and stands up in front of the front stile 22 of the piano body. The inner end on the connecting side is attracted to the stopper 15 and is held so as to extend inward of the piano body horizontally with respect to the keyboard lid 11, and the free end 12a extends rearward and upward inside the piano body and is held under the pin plate 23. On the other hand, the tongue-shaped second leaf spring 13 is oriented downward and away from the friction plate 16.

In the figure, reference numeral 24 indicates clapboards disposed on both sides of the lower side of the keyboard lid 11, and reference numeral 25 indicates a shelf board.

In this state, the keyboard lid 11 is attached to the pin shaft 11a.
When the first leaf spring 12 for braking is rotated downwardly, the free end 12a of the first leaf spring 12 for braking comes into contact with the lower surface of the pin plate 23 of the piano body, and the keyboard lid 11 stops this first leaf spring 12. The second leaf spring 13 rotates and falls while being deformed using the suction part as a fulcrum, and when the closing angle θ has advanced about 20 degrees from the upright position as shown in FIG. It comes into pressure contact with the friction plate 16 and slides on its surface, and as the lid 11 rotates thereafter, the elastic force increases due to the deformation of the first leaf spring 12 and also due to the change in the wall thickness of the plate 16. The frictional force of the second leaf spring 13 against the plate 16 increases, and the keyboard lid 11 is moved by the large elastic force of the first leaf spring 12 and the second leaf spring 13.
It closes while being braked by the frictional force of the leaf spring 13.

Then, just before the keyboard lid 11 finishes closing as shown in FIG. As a result, the closing operation of the keyboard lid 11 is made more gradual, and there is no possibility of fingers being pinched and injured.

FIG. 4 shows the above-mentioned relationship between the falling rotational torque T of the keyboard lid 11, the elastic force Fa of the first leaf spring 12, and the frictional force Fb of the second leaf spring 13 that is added to this from the middle. This is a graph of keyboard lid 1.
The torque T of the first leaf spring 1 is negative at the initial open position due to the influence of the thick rear end portion, and increases from there as the closing angle progresses. The frictional force Fb of the second leaf spring 13 added to this also increases and opposes the falling torque T of the lid 11.

On the other hand, if the keyboard lid 11 is rotated upward from the closed position shown in FIG. 2C, the lid 11 will easily return to the position shown in FIG. It will be opened in

When assembling or repairing the keyboard lid 11, the first leaf spring 12 is uncoupled from the stopper 15 and rotated upward as shown in FIG. Adjust the elastic force appropriately.

That is, if the protruding length of the stopper 15 is increased, the free end 12a of the first leaf spring 12 will touch the pin plate 2 when the keyboard lid 11 is in the upright state as shown in FIG.
Therefore, when the keyboard lid 11 is closed, the free end 12a of the spring comes into contact with the pin plate 23 earlier than before the adjustment, and the keyboard lid 11
When the spring 12 is tilted forward by a certain angle, for example 20 degrees, from the standing position, the amount of deformation of the spring 12 becomes greater than before adjustment, and the elastic force increases accordingly. Conversely, if the protruding length of the stopper 15 is reduced, the elastic force of the spring will also be reduced.

Note that FIG. 5A shows a modified example in which a tooth shape is formed on the surface of the friction plate 16 attached to the side plate 21 to enable a click operation, and FIG. This shows a modified example in which the friction plate 16 is attached and brought into pressure contact with the friction plate 16.

(Effect of the invention) This invention is structured as described above, so
During the closing operation of the keyboard lid, both the elastic force based on the deformation of the elongated first leaf spring and the gradually increasing frictional force between the second leaf spring and the friction plate,
It can suppress the downward rotation of the keyboard lid, and compared to previous models that rely solely on the elastic force generated by the deformation of the spring, it can obtain a greater braking effect, preventing damage to the instrument body or pinching of fingers. In addition, the first leaf spring can be made elongated and extend inward of the instrument body, which increases the amount of deformation of the spring and increases the braking force accordingly. As the value increases, the hit becomes softer,
Further, by adsorbing the inner end of the first leaf spring and changing the protruding length of the stopper, which serves as a rotational fulcrum of the spring, the elastic force of the first leaf spring can be adjusted. has.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the rear part of one side of the keyboard lid equipped with the opening/closing device according to this invention. Figure 2A is a partially cutaway side view of the keyboard when the lid is opened. Figure B is a partially cutaway side view when the lid is slightly closed. Figure C is a partially cutaway side view when the lid is closed. Figure 3 is a rear view of Figure 2C. FIG. 4 is a graph showing the relationship between the falling torque of the lid and the elastic force of the leaf spring. FIGS. 5A and 5B are plan views showing modified examples of the friction member, respectively. FIG. 6A is a side view of an example of a conventional device. Figure B is a vertical cross-sectional view. 7th
Figure A is a side view of another example of the conventional device. FIG. 7B is a sectional view of the rotary damper portion. In the figure, 11...Keyboard lid, 11a...Pin shaft, 1
2...First plate spring, 12a...Free end, 13...
...Second leaf spring, 13a... Base end, 14... Pin, 15... Stopper, 16... Friction plate,
21...Side plate, 21a...Supporting metal fittings, 22...Front stile, 23...Pin plate, 24...Clapboard.

Claims (1)

[Claims for Utility Model Registration] A keyboard having a braking device for a keyboard lid consisting of a tongue-shaped second leaf spring 13, an S-shaped and elongated first leaf spring 12, a stopper 15, and a friction plate 16. In the musical instrument, the tongue-shaped second leaf spring 13 is attached to the side plate 2 of the main body of the musical instrument.
The keyboard cover 11 is rotatably supported by the keyboard lid 11, and is attached via a base plate 13a to both upper sides of the rear end surface of the proximal end thereof, and its distal end curves and protrudes toward the side plate 21. The S-shaped and elongated first leaf spring 12 has an inner end joined to the upper edge of the base plate 13a of the second leaf spring 13 in a hinge shape, and a free end 12a extending rearward and upward within the main body of the instrument. The stopper 15 is formed entirely or partially of a magnet, and is attached on both sides of the rear end surface of the base end of the keyboard lid 11 under the second leaf spring 13 so that its protrusion length can be adjusted, and includes a friction plate. The second plate spring 16 is formed thicker toward the top, and is formed on the inner surface of the side plate 21.
A keyboard instrument having a brake device for the keyboard lid, which is attached along the rotation path of the tip of the keyboard.