Patent Application
20210312894
This application claims the priority of German Patent Application, Serial No. 10 2020 204 279.9, filed on Apr. 2, 2020, pursuant to 35 U.S.C. 119(a)-(d), the content of which is incorporated herein by reference in its entirety as if fully set forth herein.
The invention relates to an electronic cajon comprising a box-like base body with a bottom wall, side walls, of which the front wall forms a playing surface, as well as a cover wall, which serves as a seating surface for the player.
With traditional cajons, sound is produced by beating the playing surface. By means of different additional components, such as so-called snare elements, and by beating onto different zones of the playing surface, different sound effects, such as a high sound based on the sound of a snare drum, a bass sound or a so-called tip or slap sound can be produced.
Acoustic cajons usually are very noisy, even if they are played cautiously, with the result that a practice play is not possible without disturbing third parties, for example in a rented apartment or in a shared apartment.
An entirely different aspect is the electrical amplification of such acoustic cajons, which may be necessary when a larger auditorium shall be filled with sound. In this context, electronically amplified cajons are already known, in which an impact on the playing surface is captured by means of a mechanical-electrical signal converter, such as a piezo element, or by means of a microphone placed inside the cajon, and then converted into a correspondingly amplifiable sound signal. The cajon sound is then output in an amplified manner via an amplification system.
From U.S. Pat. No. 9,589,552 B1 and U.S. Pat. No. 10,147,409 B2 it is basically known to transmit the mechanical impact on the playing surface of a drum or cajon onto a piezo element by means of a conical foam part in order to produce an electrical pickup signal for amplified play of the sound of the cajon.
The aforementioned electronic cajons do not offer any solution to the issue explained above that during a normal, non-electrically amplified playing of the cajon, a disturbance of the environment results.
From the Spanish utility model ES 1124705 U, however, an electronic cajon is known whose upper zone of the front wall is provided with an impact surface pad, known from so-called “electronic drum sets”. These elastic pads are characterized in that by means of beating onto it, an electrical signal is produced, with the help of which a sound production unit—in the following continuously called “sound module”—is triggered, and a corresponding electrical sound signal is produced for output. Due to the elasticity of the pads, the impacts are absorbed significantly, and playing the cajon as such can take place in a relatively silent manner. If the sound signals are output via a headphone, such a cajon can be used in an optimal manner as a practice instrument even in an environment which is susceptible to acoustic disturbance.
A drawback of known electronic cajons is the fact that the pads providing for the conversion of the impacts into electrical signals are rather intended for being played on with drum sticks and thus are not construed in an optimal manner for the application with a cajon. Moreover, these pads are relatively cost-intensive.
It is therefore an object of the invention to provide an electronic cajon which can be played on in an especially silent manner, while being construed in a constructively simple manner without losses in the electrical signal quality. This makes the instrument particularly suitable for practice application in an environment which is sensitive to noise.
This object is achieved by an electronic cajon comprising a box-like base body with a bottom wall, side walls, of which the front wall forms a playing surface, as well as a cover wall, which serves as a seating surface for the player, wherein
The cajon according to the invention has numerous advantages. For instance, basically, by using a plurality of beat effect zones, an instrument is provided which can be operated silently while being able to produce a sound spectrum which is at least comparable to a classic acoustic cajon, if not broader.
The use of a rubber-like plate as playing surface results in an especially silent operation. At the same time, mounting the signal converter to the inner side of the impact plate ensures an effective transmission of the mechanical signal from the impact plate to the signal converter. Additionally, the shock absorption inlay surrounding the signal converter acoustically further reduces noise and mechanically provides for an absorbing lining of the impact plate. In this context, the formation of the beat converting device according to the invention and in particular its accommodation in a respective storage compartment in the front wall represents a very simple construction which can be produced in a cost-efficient manner while being sufficiently robust.
In the dependent claims, preferred further developments of the object of the invention are indicated, which for the sake of avoiding unnecessary repetition are explained in detail with their features and advantages in the following description of an embodiment with reference to the attached drawings.
As becomes apparent from
In the rear wall 6—as can be seen in
As becomes apparent from a synopsis of
From
The front opening of the storage compartments 15 is covered by a rubber-like impact plate 17, which for example is made of 4 mm thick vulcanized natural rubber or isoprene rubber. The surface 18 of the impact plate 17, pointing outwards, has a visual appearance of tissue. At the positions which can in particular be seen in
In its center, the shock absorption inlay 22 has a circular opening 24 in which the signal converter 20 is located and through which a connecting cable 25 of the signal converter 20 passes. The cable is guided through another opening 26 in the bottom 16 of the storage compartments 15 into the inside of the cajon and further towards the sound module 12.
The shock absorption inlay 22 is made of a 9 mm thick open-celled acoustic foam of polyurethane, whose compression hardness for example is 6 kPa and whose volume weight (in German: Raumgewicht=RG) is RG40.
By beating the respective beat effect zone 13 with the hand, the corresponding impulse is dynamically transmitted to the signal converter 20. Due to this, the latter can produce a corresponding dynamic electrical signal which is fed to the sound module 12 arranged in the base body 1 via the respective connecting cable 25. The sound module 12 converts the electrical signals of the different signal converters 20 each assigned to a beat effect zone 13 into corresponding electrical sound signals which are output on a 2-channel output 27 of the cajon—see
Furthermore, as becomes apparent from
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 204 279.9 | Apr 2020 | DE | national |
