close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2411541

код для вставки
Nov. 26, .1946.
H. c. HAYES
2,411,541
AQOUSjI‘IC WAVE GENERATING 0R RECEIVING APPARATUS
Filed Aug.‘ 8, 1936
in
mva'kron ‘
‘
Harvey C. Hayes
BY
I ATTORNEY
2,411,541
§atentecl Nov. 26, 1946
2,411,541
ACOUSTIC WAVE GENERATING 0R
RECEIVING APPARATUS
Harvey C. Hayes, Washington, D. C.
Application August 8,1936, Serial No. 94,987
19 Claims. (Cl. 177-386)
(Granted under the act of March 3, 1883, as
amended April 30, 1928; 370 0. G. 757)
,
1
My invention relatesto an acoustical appa
ratus and more particularly to an apparatus of
this character for directively generating and/or
receiving sound in a desired ?uid medium.
a
The directive generation and reception of high
‘frequency sound waves whether subaqueously or
otherwise, has been considered as best accom-'
plished by causing a disk or plate, having face
area dimensions large with respect to the sound
waves employed, to oscillate as a standing half .
wave in the direction of its thickness, that is,
in the direction perpendicular to the face area.
This determines the thickness of the disk or plate
as a half wave lengthiixed by the velocity~ of
the sound in the material of the plate at the 15
frequency at which it is designed to operate.
Much difficulty has been experienced in making
tion. However, it does not eliminate the dim
culties arising from a lack of homogeneity in
the material of the plate or head. Moreover,
these vented heads are expensive to manufacture
and give rise to dif?culties when mounting the
same ina housing by means of a ?ange, because
the flange introduces restraints that interfere
with the uniformity of amplitude and phase
across the active face area.
With the foregoing preliminary discussion in
view it is an object of my invention to provide
an acoustical apparatus for generating and/or
receiving sound wherein the sound generating
or receiving surface vibrates substantially in‘
phase and with substantially uniform amplitude
throughout its area.
v
'
the sound generating or receiving surface of the
_It is another object of my invention to pro
vide an acoustical apparatus for generating
plate oscillate in phase and with uniform ampli
and/or receiving sound-wherein the noted de
tude throughout its area. These difficulties are 20 ?ciencies of non-uniformity of amplitude of vi
bration and out of phase vibration of the sound
principally due to a lack of homogeneity of the
generating or receiving surface are substantially
plate and in particular to the radial expansion
eliminated or reduced to a negligible minimum. .
and contraction of the plate along the nodal
It is a further object of my invention to pro
plane caused by the changes of pressure therein
resulting from the half wave standing wave sys 25 vide an acoustical apparatus for generating
and/or receiving sound which is simple in con
tem perpendicular to this nodal plane. These
struction and is susceptible of being economi
pressure changes tend to cause the plate to
expand and contract along the nodal plane in
accordance with Poisson’s ratio. Thus, there is
cally manufactured and wherein the noted 'd_e
?ciencies of non-uniformity of amplitude of vi
a tendency to set up a radial standing wave 80 bration-and out of phase vibration of the sound
generating or receiving surface are substantially
system that reacts back along the half wave sys
eliminated or reduced to a negligible minimum.
tem to vary its amplitude across the plate. In
It is another and further object of my inven- '
tion to provide a substantially homogeneous vi
ter wave length 'wide about the plate or disk ,
has a lower natural frequency than the rest of 35 bratory body or mechanism of high acoustical
addition, and more seriously, a rim about a quar-_
the plate because the Poisson expansion and con
e?lciency for generating and/or receiving sound
' uniformity of amplitude and a rim area having
understood by reference to the following descrip
tion when considered in connection with the ac
wherein the noted deficiencies of non-uniformity
traction can take place here more readily than
of amplitude of vibration and out of phase vibra
elsewhere ‘since ‘the unsupported boundary in
tion of the sound generating or receiving surface.
terposes no inertia against such expansion and
contraction. As a result the restoring forces 40 are substantially eliminated or reduced to a neg
ligible minimum.
cooperative with the half wave system over this
These and other objects and many of the at
area become less and the natural frequency is
tendant advantages of this invention will be
lowered.
‘
_
readily appreciated as the same becomes better
These undesirable features, namely, lack of
lowered natural frequency and hence oscillating
out of phase with the rest of the plate both
caused by the Poisson reaction, led to my devel
opment of the vented plate or head which aims
not to eliminate. the Poisson reaction but to
distribute it uniformly across the plate. This
vented plate or head described .in my application,
S. N. 639,129, ?led October 22, 1932, goes far
toward overcoming the aforementioned undesir
able features attributable to the Poisson reac 65
companying drawing wherein:
,
Fig. 1 shows a perspective view in partial sec
tion of one embodiment of my invention which
is particularly adapted for use in cases wherein
the directivity is horizontal;
Fig. 2 shows a perspective view in partial sec
tion of another embodiment of my invention
which
"be used for either horizontally or
vertically directive work;
~
2,411,541
3
4
Fig. 3 is a partial sectional view of a still fur
ther embodiment of my invention which may be
used for either horizontally or vertically directive
work;
'
'
Fig. 4 is a partial sectional view of still another
embodiment of my invention which is designed to
facilitate in phase vibration.
Turning now to Fig. l of the drawing there is
‘ing will be free from contact with the rear of the
vibratory body 8 and the electro-mechanical
energy interchanging means i2 secured thereto.
This mounting prevents the ?uid medium 1 from
contacting the rear of the plate and the means
secured thereto and hence avoids any damping of
their free motion. While I have shown a speci?c
type of mounting for the vibratory body or mech
shown'depicted therein a metal disk I having a
anism 8 within the housing I5, I do not desire to
plurality of recesses 2. The bottom portion of 10 be limited thereto since any mounting will serve
each of the recesses is closed by the metal of the
the purpose so long as the recessed plate or body
disk at 3 and serves as a diaphragm to which any
8 is positioned to prevent the ?uid medium within
means may be secured for imparting vibratory
energy to and/or receiving vibratory energy from
a substantial homogeneous body supported there
by. As illustrative of the means secured to the
diaphragm 3 I have shown in the drawing a mag
netostrictive element or electro-mechanical en
the housing from contacting the- rear thereof and
the electro-mechanical energy interchanging
means secured thereto.
,
In Fig. 3 is shown an embodiment of my inven
tion which is similar to that of Fig. 1 except that
the recesses are ?lled with a compound having an
ergy interchanging means ll, it being apparent to
acoustical impedance substantially equal to that
those skilled in the art, however, that I may 20 of the fluid medium which it is adapted to con
employ a piezo-electrical means if desired.
The
diaphragm 3 with its attached electro-mechani
1 cal energy interchanging means d is preferably
tact.
While many compounds will readily sug
eest themselves to those skilled in the art, I have
found that certain rubber compounds may be
tuned to substantially the same natural mechan
conveniently used for this purpose. The general
ical frequency as the‘ element or body supported 25 types of soft vulcanized rubber, for example, when
in the recess above the diaphragm. In use this
immersed in water or in another liquid having
vibratory body faces with its apertures directly
similar acoustical properties, will transmit com
into the medium of propagation with the result
pressional,longitudinal sound waves,‘ the degree
"that the apertures are ?lled with the medium
of transmission varying considerably with the
whereby to provide a plurality of substantially 30 compound used. The closer the acoustical im
homogeneous vibratory elements. It is at once
pedance of the compound matches that of the
obvious that the device of Fig. 1 as well as the
medium in which it is immersed, the more elli
devices of my other embodiments may be used
ciently it will act as a propa'gational medium.
fortransmitting and/or receiving sound.
, However, the arrangement of Fig. 1 cannot be '
used for depth sounding where the plate must
face vertically downward thru an opening in the
ship's envelope because the recesses are ?lled up
in part or in whole with air When installed and
there are no means for escape during the vessel's
passage thru the ?uid medium. For such pur
poses the apertured plate is positioned within a
Any one familiar with the physical properties
required for sound'transmission and versed in
the art of compounding and processing elastic,
resilie'nt insulating substances will readily per
ceive the many compounds which can be made
from rubber alone.
‘
The rubber compound I3 is vulcanized to the
walls of the cylinder and to the bottom enclosing
diaphragm. It resonates within the cylinders
quite similarly to water or other liquid and keeps
the space free from air bubbles even when faced
housing having a‘ sound transparent window
directly in front of the recesses. The housing is
pumped free of air and ?lled with a ?uid medium
downward for depth ?nding.
such as castor oil or other liquid, having an
Fig. 4 shows an embodiment of my invention
acoustical impedance or property substantially
which is similar to that of Fig. 1 with the excep
equal to that of the fluid medium contacting the
tion that adjacent cylinders are interconnected
exterior of the sound transparent window. By
by a small passageway or perforation which is
the words “sound transparent” is meant that the 50 preferably
at the nodal plane as shown at H or
sound waves incident upon the material of the
may be otherwise placed at l5, for example,
window are neither appreciably re?ected . nor
adjacent the diaphragm. These perforations or
absorbed, this desideratum being attained when
the acoustical properties of the window material
are substantially equal to those of the ?uid
medium in contact therewith. The acoustical
properties or impedances of two substances are
alike or different depending upon whether the
products of the density and the velocity of sound
in them are alike or different.
In Fig. 2 of the drawing is shown an embodie
ment of my invention as described in the pre- .
ceding paragraph wherein 5 indicates the sound
transparent window forming a part of the hous
passageways H or ii serve as a coupling between
the several resonated columns orvibratory ele
ments and facilitate their oscillating in like phase.
Theembodiment in Figs. 2 and 3 may also be
provided withthese passageways or perforations
if desired. It is to be emphasized however, that
these passageways or perforations are not abso
60 lutely essential since the various embodiments
operate satisfactorily without them, particularly
when slightly detuned. These perforations or
passageways should be kept as short as possible.
prefer that their length should be less than a
mg 6; 1' designates the ?uid medium within the 65 Iquarter
wavelength, which wavelength is ?xed
~ housing, such as castor oil or other liquid, having
by the velocity of sound in the material of the
an acoustical impedance substantially equal to
vibratory elements at the frequency for which
that of the ?uid medium in contact with the win
the device is designed to operate. If the perfora
dow exterior; and 8v the vibratory body or mech
tions or passageways connecting, adjacent col
anism which is identical with that disclosed in 70 umns or elements are'longerthan this there is
Fig. 1 of the drawing. The vibratory mechanism
too much phase change thru the coupling to
8 is secured to the'closure member 9 of the hous
- enable the coupling to keep adjacent columns or
ing by means of the ?ange Ill projecting there-- ~
elements in phase. Moreover, if the adjacent col
from and the ?uid impervious lining ll so as to
umns are separated more than a quarter wave- ‘Q
insure that the ?uid medium 1 within the hous 75 length determined by the velocity of the sound
2,411,541
in the material ?lling the recesses of the disk and
at the frequency for which the device is designed
to operate, the combined output from all will not
give a plane wave front, but a spotted wave front,
and the required directivity or focusing effect will
be lessened.
»
_
dividual means for imparting vibratory energy to
each of said vibratory elements.
4. A vibratory mechanism comprising in com
bination a plate having a plurality of recesses, a
substantially homogeneous material ?lling each
of said recesses whereby to provide a plurality of
Regarding the length of the plate recesses or
elements therein, their diameter and relative
spacing, the following may be said; I prefer that
vibratory, substantially homogeneous elements
chanically oscillated at relatively large ampli
vibratory, substantially homogeneous elements,
and individual means for imparting or. receiving
vibratory energy respectively to or from each of
the depth or length of the recesses be de?nitely 10 said vibratory elements substantially along the
longitudinal axis thereof.
made alike and substantially equal to some whole
5. A vibratory mechanism comprising in com
number of quarter wavelengths ?xed by the veloc
bination a plate having a plurality of recesses,
ity of the sound or vibration in the material ?lling
a substantially homogeneous material ?lling each
the recesses and at the frequency for which the
of said recesses whereby to provide a plurality of
device is designed to operate. It is also preferred
vibratory, substantially homogeneous elements
that the diametercof each of the vibratory col
and individual means for imparting or receiving
umns or elements ?lling each of the recesses and
vibratory energy respectively to or from each of
the distances between the centers of each pair of
said vibratory elements substantially along the
adjacent vibratory columns or elements be not
longitudinal axis thereof, said material having an ‘
greater than a half wavelength determined by
acoustical impedance substantially equal-to that
the velocity of the vibration in the'material ?lling
of the medium of propagation with which the
said recesses and the frequency for which the
vibratory mechanism is to be used.
vibratory mechanism is designed.
6. A vibratory mechanism comprising in .com
The metal of the apertured plate or disk in all
bination a plate having a plurality of recesses, a
of my embodiments is preferably a metal having
substantially homogeneous material ?lling each
a small temperature co-efficient of elasticity and
of said recesses whereby to ‘provide a plurality of
low internal losses attendant upon its being me
individual means for imparting or receiving vi
tudes. Invar, phosphor bronze and aluminum
possess the recited preferred characteristics but 30 bratory energy respectively to or from each of
said vibratory elements substantially along the
other metals which‘ will serve the purpose equally
longitudinal axis thereof, and means for coupling
well will readily suggest themselves to those skilled
said vibratory elements to facilitate in-phase vi
in the art.
.
bration of the same.
According to the provisions of the patent stat
'7. A ‘vibratory mechanism comprising in com
utes I have-set forth the principle and mode of
bination a plate having a, plurality of recesses, a
operation of my invention and have illustrated
substantially homogeneous material ?lling each
and described what I now consider to represent
of said recesses whereby to ‘provide a plurality of
its best embodiments. However, I desire to have
vibratory, substantially homogeneous elements
it understood that within the scope of the ap
pended claims the invention may be practiced 40 and individual similar means for imparting vi
bratory energy .to ‘each of said vibrating elements
otherwise than as speci?cally illustrated and de
or receiving vibratory energy therefrom, the wall
common to each pair of adjacent recesses being
The invention herein described may be manu
perforated and the material within said recesses
factured and used by or for the Government of
the United States of America for governmental - extending into the perforations thus formed
whereby to couple said vibratory elements and to
purposes, without the payment of any royalties
facilitate in-phase vibration of the same.
thereon or therefor.
8. A vibratory mechanism comprising in com
- I claim:
bination a plate having a plurality of recesses, a
1. A vibratory body comprising in combination
scribed.
-
-
_
a plate having a plurality of recesses and a sub
stantially homogeneous material ?lling each of
said recesses whereby to provide a. plurality of
50
substantially homogeneous ‘material ?lling ‘each
of said recesses whereby to provide a plurality of
vibratory, substantially homogeneous elements
and individual similar means'for imparting vi
vibratory, substantially homogeneous elements.
bratory energy to each of said vibratory elements
said material having an acoustical impedance sub
stantially equal to that of the medium of propa 5 or receiving vibratory energy therefrom, the wall
common to each pair of adjacent recesses being
gation with which the vibratory body is to be used,
perforated and the material within said recesses‘
and individual means for driving each of said
extending into the perforations thus formed
vibratory elements.
'
whereby to couple said vibratory elements and
2. A vibratory body comprising in combination
a plate having a plurality of recesses and a sub 60 to facilitate in-phase vibration of the same and
the length of each perforation being less than a
stantially homogeneous material ?lling each of
quarter wave length Which wave length is ?xed by
said recesses whereby to provide a plurality of
the velocity of the vibration in the material ?ll
vibratory, substantially homogeneous elements,
ing said recesses and the frequency for which the
the material ?lling said recesses being that of 65 vibratory mechanism is designed.
the medium of propagation with which the vi
9. A vibratory mechanism comprising in com
bratory body is to be used, and individual means
bination a plate having a plurality of recesses, a
for driving each of said vibratory elements.
substantially homogeneous material ?lling each
3. A vibratory body comprising in combination
of said recesses whereby to provide a plurality of
a plate having a plurality of recesses and a sub~ 70 vibratory, substantially homogeneous elements
stantially homogeneous material ?lling each of
and individual similar means for imparting vi
said recesses whereby to provide a. plurality of
bratory energy to each of said vibratory elements
vibratory, substantially homogeneous elements,
means for coupling said vibratory elements to
facilitate in-phase vibration of the same, and in
or receiving vibratory energy therefrom, the
depth of each recess being substantially equal to
75 a whole number of quarter wave lengths, which
2,411,541
Wave length is fixed by the velocity of the vibra
each of which is provided at one end with a clo
sure member, a substantially homogeneous mate
tion in the material ?lling said recesses and the
frequency for which the vibratory mechanism is
designed.
10. A vibratory mechanism comprising in com
rial ?lling each of said recesses whereby to pro
vide a plurality of vibratory, substantially homo
geneous elements, and electro-mechanical en
ergy interchanging means connected to each of
said closure members, each closure member and
bination a plate having a plurality of recesses, a
substantially homogeneous material ?lling each
of said recesses wherebyiito provide a plurality of
its associated electro-mechanical energy inter
vibratory, substantially homogeneous elements
and individual similar means for imparting vi-,
ibratory energy to each of said vibratory elements
changing means together having substantially
10 the same natural mechanical frequency as the
or receiving vibratory energy therefrom, the
diameter of each of said vibratory elements being
no greater than a half wave length which wave
length is ?xed by the velocity of the vibration in
the material ?lling said recesses and the fre
quency for which the vibratory mechanism is de
signed.
11. A vibratory mechanism comprising in com
bination a plate having a plurality of recesses, a
substantially ‘homogeneous material ?lling each
of said recesses whereby to provide a plurality of
vibratory, substantially homogeneous elements
and individual similar means for imparting vi
bratory energy to each of said vibratory elements
or receiving vibratory energy therefrom, the dis
vibratory element adjacent thereto.
16. An
acoustical
apparatus - comprising in
combination a ?uid impervious housing having a
portion thereof which is sound transparent, a
substantially homogeneous ?uid medium within
said housing of an acoustical impedance sub
stantially equal to that of the ?uid medium con
tacting the housing exterior, a plate positioned
within said housing adjacent the sound trans-v
parent portion thereof and having a plurality
of recesses ?lled with the aforementioned sub
stantially homogeneous ?uid medium whereby to '
provide a plurality of vibratory substantially
homogeneous elements, and individual means for
imparting or receiving vibratory energy respec
tively to or from each of said vibratory elements.
17. An acoustical apparatus comprising in
combination a ?uid impervious housing having
tance between centers of each pair of adjacent
vibratory elements beingno greater than a half
wave length which wave length is ?xed by the ve
locity of the vibration in the material ?lling said 30 a portion thereof which is sound transparent, a
substantially homogeneous ?uid medium within
recesses and the frequency for which the vibratory
said housing of an acoustical impedance substan
mechanism is designed.
tially equal to that of the ?uid medium contact
12. A vibratory mechanism comprising in com
ing the housing exterior, a plate positioned with
bination a plate having a plurality of recesses,
asubstantially homogeneous material ?lling each ; in said housing adjacent the sound transparent
portion thereof and having a plurality of recesses
of said recesses whereby to provide a plurality
filled with the aforementioned substantially
of vibratory, substantially homogeneous elements
and individual similar means for imparting vibra
tory energy to each of said vibratory elements
or receiving vibratory energy therefrom, the 40
length of each vibratory element being substan
homogeneous ?uid medium whereby to provide
a plurality of vibratory substantially homogene
ous elements, and individual electro-mechanical
energy interchanging means for imparting or re
ceiving vibratory energy respectively to and from
each of said vibratory elements.
18. A vibratory body comprising in combina
tially equal to a whole number of quarter wave
lengths and the diameter of each of said vibra
tory elements and the distance between centers
of each pair of adjacent vibratory elements be 45 tion a plate having a plurality of recesses and a
substantially homogeneous material ?lling each
ing no greater than a half wave length, all of
of said recesses whereby to provide a plurality
said wave lengths being ?xed by the velocity
of vibratory, substantially homogeneous ele
of the vibration in the material-?lling said re
ments, the wall common to each pair of adjacent
cesses and the frequency for which the vibratory
recesses being perforated and the material with
mechanism is designed.
50 in said recesses extending into the perforations
13. A vibratory mechanism comprising in com
thus formed whereby to couple said vibratory
bination a plate having a‘ plurality of’ recesses,
elements and to facilitate in~phase vibration of
a substantially homogeneous material ?lling each
the same, and means for imparting vibratory
of said recesses whereby to provide a plurality
energy to each of said vibratory elements or for
of vibratory substantially homogeneous elements
and individual electro-mechanical energy inter
changing means connected to each of said vibra
tory elements.
14. A vibratory mechanism comprising in com
55
receiving vibratory energy therefrom.
19. A vibratory body comprising in combina
tion a plate having a plurality of recesses and a
substantially homogeneous material ?lling each
of said recesses whereby to provide a plurality of
bination a plate having a plurality of recesses,
60
vibratory,
substantially homogeneous elements,
each of which is provided at one end with a clo
the material ?lling said recesses being a rubber
sure member, a substantially homogeneous ma
compound having an acoustical impedance subterial ?lling each of said recesses whereby to pro
stantially equal to that of the medium of propa
vide a plurality of vibratory, substantially homo
gation with which the vibratory'body is to be
geneous elements, and electro-mechanical energy 65 used,
and means for imparting vibratory energy
interchanging means connected to each oi’ said
to each of said vibratory elements or for receiv
closure members.
15. A vibratory mechanismoomprising in com
binat-ion a plate having a plurality of recesses,
ing vibratory energy therefrom.
HARVEY C. HAYES.
Документ
Категория
Без категории
Просмотров
0
Размер файла
731 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа