The present application claims priority from Japanese Patent Application No. 2011-044867, which was filed on Mar. 2, 2011, the disclosure of which is herein incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a pedal device for an electronic percussion instrument.
2. Discussion of Related Art
A pedal device for an electronic percussion instrument is known. In the pedal device described in the following Patent Literature 1, a foot board is pivotably supported on a base plate (a base), and a weight is provided at a free end of the foot board. Further, a tension coil spring is provided at the free end of the foot board. The known pedal device aims at achieving a depression feeling close to that in an acoustic drum owing to an inertial force by the weight and a load increase by the tension coil spring at a time when the foot board is depressed or stepped on.
Patent Literature 1: JP-A-2008-145464
The pedal device described in the above Patent Literature 1 is placed in an equilibrium state at a position where the length of the tension coil spring is the smallest, in a non-operated state in which the foot board is not operated. The foot board has a pivotable range in which the foot board is pivotable from an initial position at which the foot board is in the equilibrium state, in both of a depression direction of the foot board and a direction opposite to the depression direction (hereinafter referred to as a “counter-depression direction” where appropriate).
When the foot board pivots in the depression direction by a depression operation by a player or performer, the tension coil spring expands or extends, so that a return force that allows the foot board to return to the initial position is the largest when the foot board is located at a lower limit position in the pivotable range. Accordingly, the arrangement advantageously attains a quick return of the foot board when the player releases his/her foot from the foot board which is in a depression state, namely, when the foot board returns to the initial position from the depression state.
However, the foot board temporarily pivots, owing to the inertia, further in the counter-depression direction after having passed the initial position. The tension coil spring is expanded also when the foot board is located at a position which is away from the initial position in the counter-depression direction. Accordingly, there acts, on the foot board, a force in a direction toward the initial position, (here, in a pivotal direction which is the same as the depression direction). Since a change of the expansion amount of the tension coil spring is larger than a change of the pivot angle of the foot board, however, the spring constant of the tension coil spring that actually acts on the foot board is large, so that the force becomes nonlinear.
As a result, in spite of the fact that the foot of the player is already raised upward by a release operation in which the foot is released from the foot board that is in the depression state, only the foot board quickly moves in the depression direction and returns to the initial position, causing a situation in which the foot board is moved downward prior to timing of a next or subsequent depression operation. In such a situation, the player feels as if he/she fails to depress the foot board, so that the operation feeling of the foot board considerably differs from that of an acoustic drum.
Thus, in a performance operation in which the depression operation and the release operation of the foot board are alternated successively, there has been a problem that the foot board does not follow the movement of the foot of the player especially in the depression operation which is conducted immediately after the release operation, and accordingly the player therefore feels an uncomfortable or unnatural feeling.
The present invention has been made to solve the conventionally experienced problem. It is therefore an object of the invention to provide a pedal device for an electronic percussion instrument in which a foot board is capable of following a movement of a foot of a player to an enhanced degree.
To attain the object indicated above, the present invention provides a pedal device for an electronic percussion instrument, comprising:
a base (10) placed on a floor surface (24);
a foot board (20) pivotably supported at one end portion (20a) thereof with respect to the base and configured to pivot in a pivotable range between a lower limit position in a depression direction and an upper limit position in a direction opposite to the depression direction; and
an elastically holding mechanism (16, 20; 20, 31, 32; 16, 20, 33; 20, 35) configured to elastically hold the foot board such that the foot board keeps an equilibrium state at an initial position within the pivotable range in a non-operated state in which the foot board is not operated,
wherein the foot board is configured such that
The reference numerals in the brackets attached to respective constituent elements of the device in the above description correspond to reference numerals used in the following embodiments to identify the respective constituent elements. The reference numerals attached to each constituent element indicates a correspondence between each element and its one example, and each element is not limited to the one example.
The above and other objects, features, advantages and technical and industrial significance of the present invention will be better understood by reading the following detailed description of embodiments of the invention, when considered in connection with the accompanying drawings, in which:
There will be explained one embodiment of the present invention with reference to the drawings.
Referring first to the schematic side view of
As shown in
A heel 19 is provided at a front part of the base portion 11 of the base plate 10, and a shaft 21 is provided at the heel 19 so as to extend in the left-right direction of the pedal device, namely, in the depth direction in
A spring support portion 17 is fixedly provided at an intermediate part of the base portion 11 in the front-rear direction of the pedal device. Further, a spring cover portion 18 is provided so as to cover the spring support portion 17. The spring support portion 17 and the spring cover portion 18 are formed as a part of the cover 12. A coil spring 16 is disposed at the spring support portion 17 so as to pass through a hole 18a formed in the spring cover portion 18. The coil spring 16 is fixed at a lower end 16b thereof to the spring support portion 17 and at an upper end 16a thereof to the lower surface of the foot board 20.
In the non-operated state of the foot board 20 in which the foot is not placed thereon and the free state of the foot board 20 in which the foot board is pivotable, the foot board 20 slightly compresses the coil spring 16 owing to its self weight, and accordingly the pedal device is kept in the equilibrium state shown in
As shown in
When the actuator 14 comes into contact with the sensor 15, the sensor 15 outputs a detection signal in accordance with the contact state. The contact area increases with an increase in a degree of deformation of the actuator 14. In other words, the contact area increases with an increase in the pivot angle of the foot board 20 in the depression direction with respect to the base portion 11. The sensor 15 is configured to have an electric resistance value which becomes smaller as the contact area with respect to the actuator 14 becomes large. By obtaining a change in the resistance value, the position of the foot board 20 and the degree of depression of the foot board 20 are detected, whereby a volume, a tone, etc. of a sound to be generated can be changed in accordance with the detected position and depression degree of the foot board 20. Here, the “pivot angle” refers to an angle of a position of the foot board 20 after it has pivoted about the pivot shaft 21 from the initial position, with respect to the initial position. In this respect, the pivot angle may be referred to as a pivot amount of the foot board 20 from the initial position.
The detection signal is outputted through a jack (not shown). The outputted signal is sent to a signal processing portion (not shown) as a percussion performance trigger signal and is converted into percussion performance data or into a sound in real time. The structure of the sensor 15 is not limited, provided that the sensor 15 is configured to detect the position and the depression degree of the foot board 20 on the basis of the pressing force from the actuator 14. For instance, the sensor 15 may be a piezoelectric sensor.
There will be next explained a structure of the coil spring 16 and a return force exerted on the foot board 20 in accordance with expansion and contraction of the coil spring 16. In the coil spring 16, its coil portion has an outside diameter which increases, in the vertical direction, from one end (lower end 16b) near to the base portion 11 toward another end (upper end 16a) remote from the base portion 11. Thus, the coil spring 16 has a generally conical shape in side view. Further, the coil spring 16 has a constant coil thickness. The coil spring 16 is configured to generate a force against the gravity that acts on the foot board 20 and apply the force from the underside of the foot board 20, thereby elastically holding the foot board 20 such that the pedal device is kept in the equilibrium state when the foot board is located at the initial position. Accordingly, when the foot board 20 is moved away from the initial position in the counter-depression direction and the coil spring 16 is accordingly expanded to a larger degree than when the foot board 20 is located at the initial position, namely, the coil spring 16 is in an expansion state, a force in the depression direction is exerted on the foot board 20 as the return force by which the foot board 20 is returned to the initial position. On the other hand, when the foot board 20 is moved away from the initial position in the depression direction and the coil spring 16 is accordingly contracted to a larger degree than when the foot board 20 is located at the initial position, namely, the coil spring is in a compression state, a force in the counter-depression direction is exerted on the foot board 20 as the return force.
In the present embodiment, the actuator 14 also generates the return force with respect to the foot board 20. However, the force generated by the actuator 14 is considerably smaller than the force generated by the coil spring 16. Accordingly, the force generated by the actuator 14 is ignorable. Further, in the present embodiment, the coil spring 16 is disposed such that the expansion amount and the compression amount of the coil spring 16 are substantially proportional to a change of the pivot angle of the foot board 20.
As shown in
When the effective range SA becomes smaller, the coil spring 16 acts as a spring whose outside diameter is small. Accordingly, the spring constant of the coil spring 16 that actually acts on the foot board 20 becomes larger than that when the pedal device is in the equilibrium state. When the foot board 20 is further depressed, the effective range SA becomes much smaller. Accordingly, the spring constant of the coil spring 16 gradually increases, and the coil spring 16 becomes the state indicated by 16-d shown in
On the other hand, when the foot is moved upwardly of the initial position immediately after the foot board 20 has been released from being depressed, the foot board 20 is moved toward the initial position by the return force for permitting the foot board 20 to be returned to the initial position and thereafter the foot board 20 pivots, owing to the inertia, in the counter-depression direction beyond the initial position. On this occasion, the coil spring 16 expands, and the return force in the forward direction for permitting the foot board 20 to be returned to the initial position gradually increases. In general, the foot board 20 begins to return to the initial position without reaching the upper limit position (at which the state of the coil spring 16 is indicated by 16-a shown in
Here, in a state in which the effective range SA is equal to the entire length of the coil spring 16, the force generated by the coil spring 16 in accordance with the expansion amount or the compression amount has a linear characteristic. In a pivot area of the foot board 20 from the initial position to the upper limit position, the coil spring 16 applies, to the foot board 20, a force having the linear characteristic in the direction toward the initial position. Accordingly, in the pivot area of the foot board 20 from the initial position to the upper limit position, the foot board 20 receives a constant force owing to its self weight, in addition to the force having the linear characteristic in accordance with the expansion amount generated by the coil spring 16. In other words, when the foot board 20 is located between the initial position and the upper limit position, the foot board 20 receives the return force having the linear characteristic with respect to the change of the pivot angle of the foot board 20 from the position of the foot board 20 at which the coil spring 16 has the natural length. On the other hand, in a pivot area of the foot board 20 from the initial position to the lower limit position, the coil spring 16 gives the foot board 20 a force having a linear characteristic in accordance with the compression amount in the direction toward the initial position, in an area from the initial position to an intermediate position between the initial position and the lower limit position, namely, until the ineffective range SB is generated, while the coil spring 16 gives the foot board 20 a force having a nonlinear characteristic (which is not linear) in accordance with the compression amount toward the initial position in an area from the intermediate position to the lower limit position. Accordingly, in the area of the pivotal movement of the foot board 20 from the initial position to the intermediate position, the foot board 20 receives the constant force owing to its self weight, in addition to the force having the linear characteristic in accordance with the compression amount generated by the coil spring 16. Further, in the area of the pivotal movement of the foot board 20 from the intermediate position to the lower limit position, the foot board 20 receives the constant force owing to its self weight, in addition to the force having the nonlinear characteristic in accordance with the compression amount generated by the coil spring 16. In other words, when the foot board 20 is located between the initial position and the intermediate position, the foot board 20 receives the return force having the linear characteristic with respect to the change of the pivot angle of the foot board 20 from the position of the foot board 20 at which the coil spring 16 has the natural length. When the foot board 20 is located between the intermediate position and the lower limit position, the foot board 20 receives the return force having the nonlinear characteristic with respect to the change of the pivot angle of the foot board 20 from the position of the foot board 20 at which the coil spring 16 has the natural length. Here, the linear characteristic may not be completely linear depending upon the disposition of the coil spring 16 such as an angle at which the coil spring 16 is disposed. In the present embodiment, however, the characteristic which is very close to the linear characteristic as compared with the nonlinear characteristic is referred to as the linear characteristic.
Thus, in the midst of the pivotal movement of the foot board 20 from the initial position to the lower limit position, namely, in the area between the intermediate position and the lower limit position, the spring constant of the coil spring 16 that actually acts on the foot board 20 becomes, large and the degree of the change of the return force with respect to the change of the pivot angle of the foot board 20 becomes large, thereby ensuring a quick return of the foot board 20 upon completion of the depression of the foot board 20. In addition, since the return force in the pivot area from the initial position to the upper limit position has the linear characteristic, the return force in the forward direction in the release operation in which the foot is released from the foot board 20 in the depression state is not excessively large and the return of the foot board 20 is not too quick. Accordingly, when the depression operation is subsequently conducted immediately after the release operation, there is unlikely to occur a situation in which the foot board 20 is moved downward prior to timing of the subsequent depression operation. Therefore, the player is prevented from feeling as if he/she fails to depress the foot board 20.
The present embodiment attains both of a quick return of the foot board 20 from the depression end poison and a not-too-quick return of the foot board 20 from a position higher than the initial position, making it possible to enhance the following property of the foot board 20 to the foot in both of the depression operation and the release operation. Accordingly in a performance operation in which the depression operation and the release operation of the foot board 20 are alternated successively, the foot board 20 follows the movement of the foot of the player especially in the depression operation which is conducted immediately after the release operation, thereby mitigating an uncomfortable or unnatural feeling as felt by the player. Further, the change of the spring characteristic of the coil spring 16 is attained by the single coil spring 16 having the conical shape, ensuring a simplified and downsized structure.
In the present embodiment, in the area from the intermediate position which is intermediate between the initial position and the lower limit position, to the lower limit position, the spring characteristic of the coil spring 16 has the nonlinear characteristic. The spring characteristic may be modified otherwise. For instance, the spring characteristic may have the nonlinear characteristic over the entire range from the initial position to the lower limit position.
The coil spring 16 needs to be interposed between the base portion 11 of the base plate 10 and the foot board 20 such that one and the other of opposite ends of the coil spring 16 are fixed to the base portion 11 and the foot board 20, respectively.
An elastically holding mechanism for holding the foot board 20 at the initial position is configured to give, to the foot board 20, the force owing to the self weight of the foot board 20 and the force in accordance with the expansion amount or the compression amount generated by the coil spring 16 so as to be superposed on each other. The elastically holding mechanism may be otherwise constructed by adding other structure to the coil spring 16. For instance, the actuator 14 may be configured to cooperate with the coil spring 16 to give the foot board 20 the force in the reverse direction, by selecting, as the material for the actuator 14, a material capable of positively generating a reaction force. In this instance, the actuator 14 is configured to have a high spring constant capable of exhibiting a definite elastic force. From a time point when the limit plate 23 begins to press the actuator 14 in the midst of the pivotal movement of the foot board 20 from the initial position to the lower limit position, the degree of increase of the force exerted on the foot board 20 becomes higher. Accordingly, the return force rapidly increases in the area of the pivotal movement of the foot board 20 in the forward direction from the intermediate position to the lower limit position. Therefore, it is possible to enhance a return speed of the foot board 20 immediately after the foot board 20 has been released from being depressed. Where the actuator 14 having a high spring constant is used, there may be used, as the coil spring, the coil spring 16 having the conical shape used in the present embodiment or there may be used other coil spring having a cylindrical shape. The coil spring having the cylindrical shape is configured to generate a force having a linear characteristic in accordance with an expansion amount or a compression amount thereof.
In the present embodiment, the coil spring 16 has the conical shape in which the outside diameter gradually changes in a direction from one of its opposite ends toward the other end. The coil spring 16 may be otherwise constructed. For instance, the coil spring may be cylindrical and may have different coil thickness values such that the coil thickness increases stepwise or linearly toward one end of the coil spring nearer to the base portion 11. Alternatively, one coil spring may be formed of a combination of different coils having mutually different spring constants by using different materials while the coil thickness is made constant.
Next, there will be explained examples of the elastically holding mechanism for giving the foot board 20 the return force having the nonlinear characteristic in the entire range from the initial position to the lower limit position or in the area from the intermediate position to the lower limit position. The examples will be explained as first through third modified embodiments with reference to
In the first modified embodiment shown in
In the thus constructed pedal device, when the foot board 20 is in the non-operated state and in the free state, the foot board 20 slightly compresses the first coil spring 31 by its self weight and the pedal device is kept in the equilibrium state shown in
On the other hand, in the pivot area from the initial position to the upper limit position, the foot board 20 receives a force generated by the first coil spring 31 owing to expansion thereof and a force owing to the self weight of the foot board 20. Since the force generated by the first coil spring 31 has a linear characteristic with respect to the change of the pivot angle of the foot board 20, the return force has a linear characteristic.
In the first modified embodiment shown in
In the thus constructed pedal device, when the foot board 20 is in the non-operated state and in the free state, the foot board 20 slightly compresses the coil spring 16 by its self weight, and the pedal device is kept in the equilibrium state shown in
On the other hand, in the pivot area from the initial position to the upper limit position, the foot board 20 is located away from the upper end 16a of the coil spring 16 except for an area that is very close to the initial position. Accordingly, the coil spring 33 gives a linear force to the foot board 20 while the coil spring 16 does not give a force to the foot board 20. When the coil spring 33 contracts to a maximum extent and cannot contract any more, the limit plate 23 abuts on the underside of the ceiling part of the rear portion of the cover 12 via the buffer member 34, whereby the upper limit position of the foot board 20 in the counter depression direction is defined.
Even in the above arrangement in which the mutually different springs are used in the area away from the initial position in the depression direction and in the area away from the initial position in the counter-depression direction for giving the force to the foot board 20, the characteristic of the return force with respect to the change of the pivot angle of the foot board 20 is similar to that in the illustrated embodiment of
In this second modified embodiment, for obtaining the return force having the nonlinear characteristic in the entire range from the initial position to the lower limit position, the buffer member 34 may be fixed to the limit plate 23. Further, the coil spring 33 may be constructed so as to be fixed to the limit plate 23 via the buffer member 34, without being fixed to the underside of the ceiling part of the rear portion of the cover 12. In such a configuration, the characteristic of the return force with respect to the change of the pivot angle of the foot board 20 can be made similar to that in the illustrated embodiment of
In the thus constructed pedal device, when the foot board 20 is in the nonoperated state and in the free state, the foot board 20 slightly flexes the leaf spring 35 by its self weight, and the pedal device is kept in the equilibrium state shown in
On the other hand, in the pivot area from the initial position to the upper limit position, the leaf spring 35 is located away from the foot board 20 except for an area that is very close to the initial position. Accordingly, as in the second modified embodiment, the return force in the depression direction having a linear characteristic is given to the foot board 20.
In the third modified embodiment, the leaf spring 35 may be disposed such that its free end is always held in pressing contact with the lower surface of the foot board 20. In the third modified embodiment, the portion of the upper surface of the support base 36 from the first pivot point P1 to the second pivot point P2 may be formed as a curved surface which is convex upward, and the most forward contact position on the portion of the upper surface of the support base 36 may be gradually shifted frontward. In such a configuration, the degree of increase of the return force with respect to the increase of the depression angle gradually becomes hither in the depression stroke
As described above, various kinds of elastic member such as springs in various forms may be employable as the elastically holding mechanism, and the elastically holding mechanism is not limited to those illustrated above.
In the illustrated embodiment and the modified embodiments, the structure for defining the upper limit position of the foot board 20 in the counter-depression direction, as an upper-limit-position defining mechanism, is not limited to the limit plate 23 and the stopper portion 13. For instance, as the upper-limit-position defining mechanism, there may be employed a structure according to a fourth modified embodiment shown in
The position at which the engaging member 25 is disposed is intermediate in the front-rear direction of the foot board 20. At the position, the pivot amount of the engaging member 25 is smaller as compared with the pivot amount of the limit plate 23. Therefore, the size of the cover 12 can be reduced. The engaging member 25 and the stopper portion 26 may be disposed at a position closer to the pivot shaft 21.
While the embodiment and the modified embodiments of the present invention have been described in detail by reference to the accompanying drawings, it is to be understood that the present invention may be embodied with various other changes and modifications, which may occur to those skilled in the art, without departing from the spirit and scope of the invention defined in the appended claims.
Number | Date | Country | Kind |
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2011-044867 | Mar 2011 | JP | national |