Speaker System

The present invention generally relates to speaker systems and more particularly to a speaker system wherein a speaker is attached to a cylindrical enclosure at a predetermined position on the cylindrical side wall thereof.

Speaker systems having a cylindrical enclosure known heretofore have been constructed by disposing a speaker at the top or bottom of the cylindrical enclosure facing upward or downward, and further by providing a cone-formed diffuser so that it confronts the front of the speaker to distribute or diffuse the sound radiated from the speaker upward or downward to the side or horizontal direction. In the conventional speaker system of this type, the speakers are located at the top or the bottom of the enclosure. This conventional speaker system is therefore accompanied by difficulties where the magnitude of the sound pressure imparted to the enclosure has extreme differences between the upper and lower parts of the enclosure, whereby the preferred sound is not radiated.

Accordingly, it is a general object of the present invention to provide a novel and useful speaker system which overcomes the above described difficulties.

Another object of the present invention is to provide a speaker system in which a speaker is attached to the side wall of a cylindrical enclosure through an opening formed thereat. In the speaker system according to the present invention, the sound pressure is uniformly imparted to the whole area of the inner side of the enclosure, whereby a preferred sound radiation is accomplished.

Another object of the present invention is to provide a speaker system in which a paper pipe, which is formed by spirally winding a card board in a cylindrical shape, is employed for the above described cylindrical enclosure. The speaker system of the present invention as manufactured is less expensive.

Still another object of the present invention is to provide a speaker system in which a folded horn may be easily formed between the outer peripheral surface of the cylindrical enclosure and the inner surface of an external casing accommodating the enclosure therein. The speaker system of this arrangement preferably radiates sound of the lower frequency range.

Other objects and further features of the present invention will be apparent from the following detailed description set forth in conjunction with the accompanying drawings.

In the drawings:

FIG. 1 is an elevation, in vertical section, showing a first embodiment of a speaker system according to the present invention;

FIG. 2 is a plan view in transverse section taken along the line II--II in FIG. 1 and viewed in the arrow direction;

FIG. 3 is a perspective view showing a cylindrical enclosure of the speaker system in FIG. 1;

FIG. 4 is a perspective view showing a state where the speaker system in FIG. 1 is accommodated within a speaker accommodation box or outer casing;

FIG. 5 is a vertical section showing a second embodiment of the speaker system according to the present invention;

FIG. 6 is a transverse section taken along the line VI--VI in FIG. 5;

FIG. 7 is a transverse section showing a third embodiment of the speaker system of the present invention;

FIG. 8 is a transverse section showing a modification of the speaker system illustrated in FIG. 7;

FIG. 9 is a vertical section showing a speaker system structure which can be used in the speaker system indicated in FIG. 7 and FIG. 8;

FIG. 10 is a perspective view showing a speaker accommodation box which can be used in the speaker system illustrated in FIG. 7 and FIG. 8;

FIG. 11 is a transverse section showing a fourth embodiment of the speaker system of the present invention; and

FIG. 12 is a transverse section showing a modification of the speaker system illustrated in FIG. 10.

Referring to FIG. 1 and FIG. 2, a speaker system 11 is substantially constructed with a cylindrical enclosure 12 and a speaker 13.

The enclosure 12 consists of a so-called paper pipe cut in a predetermined length and having a cylindrical side wall 14. The paper pipe is formed, as illustrated in FIG. 3, by winding a card board 14a having a predetermined spiral thickness and by gluing or cementing the overlapped edge thereof. The cylindrical side wall 14 is coated with a paint layer 14b, as indicated by a two-dotted chain line in FIGS. 1 and 2. The paint layer 14b is formed by coating paints such as varnish over a whole surface including the external and internal surfaces thereof. A window opening 14c is formed on the side wall 14 at a substantially intermediate height position thereof. A buffle plate 15 is of a quadrangle flat plate made of plastic, and has a circular opening 15a formed at a center part thereof. This buffle plate 15 is attached to the opening 14c in such a manner that the upper and lower parts thereof are supported by crescent shaped plates 16a and 16b, and either sides thereof are fixed directly to the side wall 14.

A speaker 13 is attached to the buffle plate 15 by being fixed an outer peripheral part 17b of a housing 17 with screws 18 in a state where the speaker 17 is wholly accommodated within the enclosure 12. Accordingly, the front surface of the speaker 13 is positioned at a position defined by a predetermined distance from the outer peripheral surface of the side wall 14. A drone cone 19 is disposed at the bottom opening of the enclosure 12, and is attached by fixing an outer peripheral part 19a to an opening 21a formed on a base plate 21 of an accommodation box 20 described hereinafter. Accordingly, when the speaker system 11 is accommodated within the accommodation box 20, the speaker system 11 is supported by the outer peripheral part 19a of the drone cone 19, as illustrated in FIG. 1. The top opening of the enclosure 12 is covered by a top plate 22 of the accommodation box 20.

Thus, in the speaker system 11 having a construction described hereinbefore, the speaker 13 is disposed at an intermediate height position of the cylindrical speaker enclosure 12. Accordingly, when the speaker 13 radiates sound, pressure of the sound is imparted to the top and bottom parts of the enclosure 12 in substantially same level, whereby the above described sound pressure acts equally over the substantially whole area inside of the enclosure 12.

Moreover, since the cylindrical side wall 14 of the enclosure 12 is made of card board, the sound radiated from the speaker 13 is absorbed appropriately by the side wall 14, whereby the necessity for providing a large amount of sound absorbing material is now obviated. Furthermore, since the cylindrical side wall 14 winding formed by spirally the card board it forms a construction which is uneven in the longitudinal direction and lateral direction. The sounds reflected by the inner surface of the side wall 14 are cancelled with each other in all directions, whereby occurrance of resonance is therefore prevented. Noises in the radiated sound are reflected by the paint layer 14b and are confined in the enclosure 12 and do not radiate outside. Therefore, in accordance with and speaker apparatus 11 constructed as described hereinbefore, extremely preferred sound can be obtained.

The accommodation box 20 is constructed, as illustrated in FIG. 4, by fixing the base plate 21 and the top plate 22 to four poles 23a through 23d (the pole 23d is not shown). Further, the rear side of the accommodation box 20 is covered with a plate 24, while the other three sides thereof are covered with textile fabric 25a through 25c.

When the speaker system 11 is accommodated within the accommodation box 20, the speaker system 11 is inserted or loaded into the box 20 from the lower side of the base plate 21 through the opening 21a and then, a drone corn 19 is attached to the base plate 21 as illustrated in FIG. 1. The textile fabric 25d is stretched at the lower side of the drone corn 19.

Next, a second embodiment of the speaker system according to the present invention will be described in conjunction with FIG. 5 and FIG. 6. In both figures, parts which are the same as those in FIGS. 1 and 2 are designated by the like reference numerals and the description thereof is not repeated.

In a speaker system 31, a support member 32 to which the speaker 13 is attached is fixed to the side wall 14 of the enclosure 12 through an opening 14d formed thereat. The front surface of the speaker 13 is substantially in the same plane as the tangential plane of the outer peripheral surface of the side wall 14 or projects slightly from the side wall 14. The assembling manner for accommodating the speaker system 31 in the accommodation box 20 is exactly the same as that of the above described speaker system 11.

However, the present invention is not restricted to the above described embodiments having the single speaker 13, but other modifications in which a plurality number of speakers are arranged in logitudinal direction of the enclosure may be employed.

Moreover, in the embodiments described above, the speaker systems 11 and 31 are provided with the drone corn 19, but the drone corn 19 may be omitted. Further, by forming an opening having a predetermined configuration at a predetermined position on the cylindrical side wall 14, the enclosure 12 performs as a bass-reflex enclosure.

In the above described embodiment, the enclosure 12 itself has the sound absorbing properties because the enclosure 12 is made of card board. However, the absorbing material such as glass-wool may be filled within the enclosure 12 for enhancing the sound absorbing effect.

Next, a third embodiment of a speaker system according to the present invention will be described with reference to FIG. 7. A speaker apparatus structure 11.sub.1 has a construction in which the enclosure 12 has a window opening 14e formed on the side wall 14 thereof, and a flange 42 is fitted to the bottom part of the side wall 14. The drone cone 19 and the opening 14c are omitted. The window opening 14e has a size smaller than the window opening 14c. An outer casing 41 has the shape of a box formed of side plates 41b, 41c, and 41d, a base plate 41a, and a top plate 41e, as illustrated in FIG. 10. Guide plates 43a and 43b are respectively provided at two corners formed by the side plates 41b, 41c, and 41d. Over the front side of the outer casing 41, a fabric net 44 is held in tension.

In FIG. 7, the speaker system structure 11.sub.1 is mounted on the base plate 41a of the outer casing 41 at a center part thereof by screws 44, and the window opening 14e on the side wall 14 confronts the rear side plate 41d at a position in the vicinity thereof. Thus, folded horn parts 45a and 45b, which are symmetric with each other and have increasing sectional areas toward the front, are formed or defined between the inner surface of the outer casing 41 including the guide plates 43a and 43b and the outer peripheral surface of the side wall part 14. The sound radiated from the speaker 13 is throttled at the window opening 14e thereby causing the sound pressure to increase, and thereafter, as indicated by the arrow in the same figure, is reflected by the rear side plate 41d thereby being separated to the right and left, and further advances forward and is guided by the folded horn parts 45a and 45b. The preferred reproduced sound can be obtained having a preferred characteristic in the lower frequency range due to the effect of the holded horn parts 45a and 45b. Moreover, since at least the outer peripheral surface of the side wall 14 is a curved surface, the above described folded horn parts 45a and 45b resemble a more preferable horn configuration, whereby the preferred reproduced sound can be obtained.

FIG. 8 shows a modification of the speaker system indicated in FIG. 7. The speaker system 11.sub.1 is disposed at a position deviated to the right in the outer casing 41, whereby the window opening 14e confronts the guide plate 43b at a position in the vicinity thereof. Thus, a single folded horn part 46 is formed or defined between the inner surface of the outer casing 41 and the outer peripheral surface of the side wall 14. The sound radiated from the speaker 13 is throttled at the window opening 14e, and the sound thus having a relatively high sound pressure is reflected by the guide plate 43b. The sound reflected by the guide plate 43b advances toward left and further advances forward and is guided by the folded horn part 46, as indicated by the arrows in FIG. 8. Accordingly, the preferred reproduced sound can be obtained, similarly as in the preceding case.

FIG. 11 shows a fourth embodiment of the speaker system of the present invention. A speaker system structure 11.sub.2 has a construction in which a window opening 14f is formed on the side wall 14 of the speaker system 11 of the first embodiment at the rear part of the speaker 13, the drone corn 19 is removed, and the flange 42 is attached to the enclosure 12. The speaker system 11.sub.2 of the above described construction is disposed at a center substantially within the outer casing 41, so that the speaker 13 faces forward and the window opening 14f confronts the rear side plate 41d at a position in the vicinity thereof, thereby forming the folded horn parts 45a and 45b in the same manner as in the embodiment illustrated in FIG. 7.

In this arrangement, the sound of middle and higher frequency ranges is directly radiated forward from the front of the speaker 13. While, the sound in the lower frequency range radiated backward from the rear of the speaker 13 is throttled at the window opening 14f thereby causing the sound pressure to increase, and thereafter, advances forward and is guided by the folded horn parts 45a and 45b. Thus, a preferred sound in the lower frequency range can be obtained, similarly as in the preceding embodiment.

FIG. 12 shows a modification of the embodiment illustrated in FIG. 11. The speaker system structure 11.sub.2 is disposed at a substantially right side within the outer casing 41, so that the speaker 13 faces toward left-front direction and the window opening 14f confronts the guide plate 43b in the vicinity thereof, thereby forming or defining the folded horn part 46, similarly as in the embodiment in FIG. 8. Accordingly, the sound in the middle and higher frequency ranges is preferably radiated to the left-front direction from the front of the speaker 13, whereas the sound in the lower frequency range is preferably radiated backward and then advances forward and is guided by the folded horn part 46.

Here, the speaker system structures 11.sub.1 and 11.sub.2 in respective embodiments and modifications thereof illustrated in FIG. 7 through FIG. 12 have the structures obtained by modifying the speaker system of the first embodiment but the modified structure based on the system of the second embodiment illustrated in FIGS. 5 and 6 may be adopted.

Moreover, the window openings 14e and 14f of the speaker systems 11.sub.1, 11.sub.2, and 31 are respectively of quadrangle extending lengthwise in the above described embodiments. However, the configuration of the opening is not limited to this, but any other configurations such as quadrangle extending laterally and circle may be adopted. Further, the position of the window opening 14f is not restricted to being rear of the speaker 13, but it may formed at any other angular position and height position.

Furthermore, the states of disposing the speaker systems 11.sub.1, 11.sub.2, and 31 with respect to the outer casing 41 are not restricted to the above described respective embodiments. For instance, the speaker system is disposed in a state where the window opening 14f confronts the guide plate 43a in the vicinity thereof. Furthermore, any other disposing states may be adopted, provided that proper folded horn parts are formed or defined.

Further, this invention is not limited to these embodiments but various variations and modifications may be made without departing from the scope and spirit of the invention.