U.S. patent number 3,642,091 [Application Number 04/865,090] was granted by the patent office on 1972-02-15 for underground acoustic device.
This patent grant is currently assigned to Pioneer Electronic Corporation. Invention is credited to Shunji Nohara, Hideo Watanabe.
United States Patent |
3,642,091 |
Nohara , et al. |
February 15, 1972 |
UNDERGROUND ACOUSTIC DEVICE
Abstract
An underground acoustic device for radiating sound into the
atmosphere has a casing with a folded horn within the same, the
casing constituting a tubular member, for example, a cylinder, an
inverse truncated cone, a prism, or an inverse truncated pyramid.
The hollow tubular casing defines a cavity with a speaker and a
folded horn integral therewith supported at the center of the
casing bottom to radiate sound upwardly towards the atmosphere. The
bottom of the casing is configured to radiate sound upwardly and
outwardly through a series of holes in a cover overlying the casing
opening. In turn, the center of the cover is provided with a cover
with a conical projection facing the speaker hole and acting in
conjunction with a cup or cylindrical extension larger in diameter
than the speaker horn for reflecting sound downwardly toward the
curved reflecting surface of the bottom of the cavity. A drain pipe
extends from the inside of the casing to the underground and a net
lies intermediate the ends thereof for preventing rats from
entering the casing.
Inventors: |
Nohara; Shunji (Tokyo,
JA), Watanabe; Hideo (Tokyo, JA) |
Assignee: |
Pioneer Electronic Corporation
(Tokyo, JA)
|
Family
ID: |
13508803 |
Appl.
No.: |
04/865,090 |
Filed: |
October 9, 1969 |
Foreign Application Priority Data
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|
|
|
Oct 9, 1968 [JA] |
|
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43/73110 |
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Current U.S.
Class: |
181/150;
181/152 |
Current CPC
Class: |
H04R
1/345 (20130101); H04R 1/028 (20130101) |
Current International
Class: |
H04R
1/02 (20060101); H04R 1/34 (20060101); H04R
1/32 (20060101); G10k 013/00 (); H04r 001/28 () |
Field of
Search: |
;181/31.1,31A,27E |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Publication "Manhole Speakers" by W. E. Shrage Radio-Craft Dec.
1938, pp. 340, 359. .
Publication "Ground Loudspeakers" by David Scott Audio Engineering
Oct. 1949 pp. 18-19..
|
Primary Examiner: Tomsky; Stephen J.
Claims
What is claimed is:
1. An underground acoustic device for radiating sound from the
ground into the atmosphere comprising: a hollow tubular member
positioned within the ground, means including said hollow tubular
member defining a cavity with an upper opening, a speaker including
a horn coaxially positioned within and fixed to the bottom of said
means defining said cavity with the speaker horn facing upwardly
towards said opening of said hollow tubular member, the bottom of
said cavity being curved to form a path for the sound, a cover
overlying the open upper end of said hollow tubular member and
carrying multiple holes for passing the sound therethrough except
at the center portion thereof, a conical projection beneath and at
the center of the cover, a cup-shaped generally cylindrical,
sound-reflecting horn concentrically surrounding said conical
projection for reflecting the sound radiated from said speaker
toward the sound-reflecting curved surface of the cavity bottom,
thence outwardly through said multiple holes.
2. An underground acoustic device as set forth in claim 1, wherein
said hollow tubular member is of cylindrical prism shape.
3. An underground acoustic device as set forth in claim 1, further
comprising a drain channel formed around said cover at the edge
thereof.
4. An underground acoustic device as set forth in claim 1, wherein
the bottom of said cavity is formed by the ground and said ground
includes salt as a component thereof for varying the quality of the
sound reflected therefrom.
5. An underground acoustic device as set forth in claim 1, wherein
said multiple holes are inclined radially outwards towards the
periphery of the cover to control the direction of sound radiated
from the acoustic device.
6. An underground acoustic device as set forth in claim 1, wherein
said speaker is a woofer.
7. An underground acoustic device as set forth in claim 6, further
comprising an illumination lamp standing on the center portion of
said cover and having a base formed with a reflecting surface or
reflecting the woofer sound radiated from said woofer speaker and a
plurality of waterproof tweeter speakers provided on said
reflecting surface.
8. An underground acoustic device as set forth in claim 7, wherein
said illumination lamp comprises a mercury-arc lamp having a cover
formed by acryl resin overlying the same.
9. An underground acoustic device as set forth in claim 7, wherein
the holes within said cover are inclined in the direction of the
cover periphery to direct the sound as individual acoustic
reflectors.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an underground acoustic device having a
speaker for radiating a sound into the atmosphere.
2. Description of the Prior Art
Heretofore, when the announcements and sound music broadcasting are
provided for the street advertisement or as a guide in an outside
exhibition, the speaker is attached to a telegraph pole or a tree.
This requires not only a pole, but also a cord must be stretched
through the atmosphere which spoils the appearance of the place.
Particularly for a park or garden, the atmosphere of the place is
defiled. Since the broadcasting is done directly from overhead of
the persons walking on the street, the walker hears the sound
badly. Moreover, as the rain or dew falls directly on the speaker
the speaker is corroded even if it is waterproof and this shortens
its life.
This invention eliminates the aforementioned disadvantages of
conventional speakers and provides an underground acoustic device
for radiating sound into the atmosphere from underground to allow
the walker to experience a strange sound to increase the
advertising affect.
The present invention provides an underground acoustic device in
which the acoustic effect may be varied by forming various shapes
of the sound passage from the speaker to the surface of the
ground.
The present invention also provides an underground acoustic device
which does not have to be set on a pole and which does not need a
cord stretched into the atmosphere so as not to spoil the
appearance of the street or other place. The invention also
provides an underground acoustic device which does not directly
receive rain or dew on the speaker so as not to corrode the speaker
and lengthens the life of the speaker.
According to one aspect of the present invention, there is provided
an underground acoustic speaker for radiating sound into the
atmosphere which comprises a casing formed with a folded horn
integrally therein. The casing is in the form of a hollow tubular
member, for example, a cylinder, an inverse truncated cone, a
prism, or an inverse truncated pyramid with a conical projection at
the center of the bottom thereof for radiating the sound toward the
atmosphere from a speaker attached to the cover thereof. A drain
pipe extends underground from the inside of the casing and has a
net intermediate its ends for preventing animals from entering the
casing. The cover of the casing has multiple holes for passing the
sound therethrough except at the center portion to which is
attached the speaker .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of an underground acoustic device
constructed in accordance with the present invention.
FIG. 2 is a perspective view of the underground acoustic device of
FIG. 1 as seen from above ground.
FIG. 3 is a sectional view similar to FIG. 1, but showing another
embodiment of the present invention.
FIG. 4 is a sectional view similar to FIG. 1, but showing a further
embodiment of the present invention; and
FIG. 5 is a sectional view similar to FIG. 1, but showing still
another embodiment thereof.
Reference is now made to the drawings and particularly to FIGS. 1
and 2, which show one embodiment of the underground acoustic device
of the present invention. The underground acoustic device comprises
a casing 1 made of concrete and formed with a folded horn
integrally therein. Casing 1 is in the form of a hollow tubular
member, for example, a cylinder as illustrated; but alternately it
may be in the form of an inverse truncated cone, a prism, or an
inverse truncated pyramid. In this case, it includes an integral
bottom 11 which carries a speaker 2, having a horn 21 attached
thereto. Casing 1 has a conical projection formed at the center of
the bottom 11 for radiating sound from said speaker 2 towards the
atmosphere. Said bottom has a reflecting surface 11a for reflecting
the sound radiated from the speaker 2. A drain pipe 3 opens at the
reflecting surface 11a at one end and communicates the inside of
the casing 1 to the ground. A net 31 is provided intermediate of
the ends of pipe 3 for preventing animals such as a rat or dust
from entering into the casing 1. A cover 4 is attached to the
stepped opening 13 of the casing 1 and has multiple holes 42 formed
within the cover 4 for passing the sound therethrough except at the
center portion 41 which couples the speaker 2 on the inside thereof
in such a manner that the horn 21 of the speaker 2 faces towards
the bottom 11 of the casing 1. The speaker 2 may preferably be a
waterproof dome horn speaker in order to obtain good acoustic
effects. By forming the casing 1 of the acoustic device as an
extension of the horn, the characteristics of the speaker may be
improved.
In operation of the underground acoustic device thus constructed,
the sound from the speaker 2 is radiated outwardly through the horn
21 and the folded horn defined by the inside of the casing 1 with
high efficiency from the ground to the atmosphere. When the rain
falls on the underground acoustic device, the water passing into
the casing 1 is exhausted through the drain pipe 3 into the
surrounding ground.
Referring now to FIG. 3, which shows another embodiment of the
underground acoustic device constructed in accordance with the
present invention like parts and components are designated by the
same reference characters as those shown in FIG. 1. The underground
acoustic device comprises a casing 1 made of concrete in the form
of a hollow tubular member, for example, a cylinder as shown, or
alternatively, an inverse truncated cone, a prism, or an inverse
truncated pyramid, the bottom being integral therewith and the
outer corner at the bottom being curved, as shown. The bottom 11
has a plurality of drain holes 14 for exhausting water from the
casing 1 into the ground. A speaker 2 having a horn 21 attached
thereto is attached to the inside surface of the bottom 11 of the
casing 1 in such a manner that the horn 21 of the speaker faces the
stepped opening 13 of the casing 1. The bottom 11 includes a
reflecting surface 11a for the sound. A cover 4 is attached to the
stepped opening 13 of the casing 1 and has multiple holes 42 formed
therein for passing sound therethrough except at the center portion
41. A conical projection 44 is formed at the inside center of the
cover and a generally cylindrical sound-reflecting horn 43 extends
coaxially around the conical projection 44 for reflecting the sound
radiated from the speaker 2.
In operation of the underground acoustic device thus constructed,
the sound radiated from the speaker 2 is reflected through the
second horn 43 formed by the generally cylindrical sound-reflecting
member 43 so that the thus reflected sound is again reflected to
the third horn 11a defined by a position of the bottom 11 of the
casing 1. The sound then passes through holes 42 of the cover 4
from the underground into the atmosphere with high efficiency. When
the rain falls on the underground acoustic device, the water
passing into the casing 1 is exhausted through the drain holes 14
formed in the bottom 11 of the casing 1 and passes into the
ground.
Reference is now made to FIG. 4, which shows a further embodiment
of the underground acoustic device of the invention. The
underground acoustic device comprises a casing or cylinder 1 made
of concrete in the form of a hollow tubular member, for example, a
cylinder as shown, or alternatively, an inverse truncated cone, a
prism, or an inverse truncated pyramid, and forming in this case
with the ground 5, a cylindrical cavity with the ground acting as a
bottom thereof. A speaker 2 having a horn 21 attached thereto is
attached to the ground 5 in such a manner that the horn 21 of the
speaker 2 faces the opening 13 of the cylinder 1. The bottom of
ground 5 is preformed into a reflecting surface 11a for the sound.
A cover 4 is attached to the stepped opening 13 of the cylinder 1
and has multiple holes 42 formed therein for passing the sound
therethrough except at the center portion 41. A conical projection
61 is formed at the center of the cup-shaped, generally cylindrical
sound reflecting horn 6 formed coaxially around the conical
projection 61 to the inside thereof for reflecting sound radiated
from the speaker 2. A drain channel 7 is formed around the cover 4
at the edge of the stepped opening 13.
Salt is mixed into the ground 5 if the ground 5 is soft, and a
proper hardness to the ground 5 is thus obtained. Any desired
hardness may be obtained for the ground 5 so that various qualities
of sound are radiated from the speaker 2. Particularly if high
sound is desired, it is preferable that the ground 5 provides a
hard reflecting surface.
The speaker 2 may be attached to the cup-shaped generally
cylindrical sound-reflecting horn 6 or hung therefrom, and, an
acoustic reflector formed by plates may be provided on the cover 4
so as to optionally vary the direction of the sound radiated from
the acoustic device.
In operation of the underground acoustic device thus constructed,
the sound radiated from the speaker 2 is reflected by the
cup-shaped generally cylindrical sound-reflecting horn 6 so that
the thus reflected sound is again reflected by the third horn
formed by the ground 5 to finally pass through holes 42 of the
cover 4 and from underground into the atmosphere with good
efficiency. When the rain falls on the underground acoustic device,
the water passing into the cylinder 1 is directly absorbed by the
ground 5.
Referring now to FIG. 5, which shows still another embodiment of
the underground acoustic device, the acoustic device comprises a
cylinder 1 made of concrete and in the form of a hollow tubular
member, for example, a cylinder as shown, or alternatively, an
inverse truncated cone, a prism, or an inverse truncated pyramid,
and forming in this case with the ground 5, a cylindrical cavity
with the ground acting as the bottom of the cavity. A woofer
speaker 2 has a horn 21 attached thereto and is attached to the
ground 5 in such a manner that the horn 21 of the speaker 2 faces
the opening 13 of cylinder 1. The bottom of ground 5 forms
reflecting surface 11a for the sound. A cover 4 is attached to the
stepped opening 13 of cylinder 1 and has multiple holes 42 for
passing the sound therethrough except at the center portion 41
thereof to which is attached a conical projection 61 lying at the
inside center of a cup-shaped, generally cylindrical
sound-reflecting horn 6 extending coaxially around the conical
projection 61 for reflecting the sound radiated from the speaker 2.
An illumination lamp 8 such as, for example, mercury-arc lamp
stands on the center portion 41 of the cover 4 and has a base 81
provided with a reflecting surface 81a. This reflects the woofer
sound radiated from the woofer speaker 2 and a plurality of
waterproof tweeter speakers 9 provided within the reflecting
surface 81a. The mercury-arc lamp 8 has an illumination portion 82
and a cover 83 formed of acryl resin which is provided on the lamp
8. The tweeter speakers 9 may preferably be selected so as to
provide a proper directivity of the sound radiated therefrom.
In operation of the underground acoustic device thus constructed,
the sounds radiated from both tweeter and woofer speakers 9 and 2
is radiated in such a manner that the woofer sound radiating from
the speaker 2 is reflected from the cup-shaped generally
cylindrical sound-reflecting horn 6 and thus reflected sound is
again reflected by the third horn formed by the ground 5 to pass
through the holes 42 of cover 4 from underground into the
atmosphere. The sound contacts reflecting surface 81a for
reflection so as to spread the sound over the ground surface and
not to radiate it vertically. The tweeter sound is radiated over
the ground surface from the reflecting surface 81a directly and
accordingly the mixture of woofer and tweeter sounds are spread all
over the ground to produce a good acoustic effect with a better
quality to the sound. Since the tweeter speakers are provided under
the illumination lamp 8, the tweeter speakers 9 are not seen from
the outside and this provides a good appearance.
The cover 4 is provided with holes 42 which are inclined to act as
a deflector thereby radiating the sound in a broader manner to the
atmosphere. The holes 42 are inclined in the direction of the
periphery of the cover 4.
It is understood from the foregoing description that the speaker is
buried underground within the casing so that the announcement or
broadcasting of the music is radiated from the ground with the
result that makes a strong impression on the walker for a good
advertising effect. A good appearance may be provided and the rain
or dew may not fall directly onto the speaker to reduce the life
thereof.
It is also understood that since the sound is reflected at the
folded structure after being radiated from the speaker good
acoustic characteristics are obtained to suit public parks or
gardens.
* * * * *