US2434469A

US2434469A - Pressure-proof reproducer

Info

Publication number: US2434469A
Application number: US543149A
Authority: US
Inventors: William A Myers
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-07-01
Filing date: 1944-07-01
Publication date: 1948-01-13
Anticipated expiration: 1965-01-13

Description

Jan. 13, 1948. W.'A. MYERS PRESSURE-PROOF REPRODUCER 2 Sheets-Sheet l 7 Filed July 1, 1944 INVENTOR. WILLIAM A. MYERS ATTORNEY Jan. 13, 1948, w. A. MY RS 2,434,469-

' PRESSURE-PROOF REPRODUCE-R 2 Sheets-Sheet 2 Filed July 1, 1944 INVENTOR. WILLIAM A. MYERS ATTORNEY Patented Jan. 13, 1948 PRESSURE mnoor REPRODUCER William A. Myers, San Diego, Calif., assignor to the United States of America, as represented by the Secretary of the Navy Application July 1, 1944, Serial No. 543,149

4 Claims. (01. 181--31) This invention relates to reproducers and more particularly to those of a type in which the speaker may be submerged in a liquid medium under high pressure.

Where speakers are used in and around water, it is often necessary for them to remain partially or wholly covered with water for considerable periods of time, and yet to be ready for immediate use. Unless means are utilized for protecting the speaker cone (and associated circuits), the units soon become inoperable. For example, where such speakers are used on piers, ships or submarines, they may be thoroughly wetted periodically, and additionally, may be subjected to great pressures due to water depth or explosions, if mounted externally of a submarine as a part of an inter-communicating system.

The present invention provides means for protecting a speaker from the effects of submergence and pressure without unduly altering its operating characteristics. This is generally accomplished by housing the speaker in a waterand pressure-proof housing and providing a flexible, water-proof diaphragm over a portion or all of the face of the speaker.

In the drawings:

Fig. 1 is a sectional view of one form of the invention with portions oi the unit shown in elevation.

Fig. 2 is a sectional view along the line 2-2 of Fig. 1.

Fig. 3 is a sectional View of another form of the invention. 1iFig. 4 is a sectional view along the line 4-4 of The form of the invention illustrated in Figs. 1 and 2 comprises a relatively heavy, metal, cylindrical housing I which is capable of withstand ing considerable pressure. A mounting plate 2 is welded at 2 to one of the ends of said housing to form a waterand pressure-proof closure. This plate is provided with several mounting holes as at 3. At the opposite end of the housing is an outwardly extending flange 4 provided with a series of threaded holes, as at 5, for a purpose to be described. The outer end of the wall of the housing I is also provided with a groove, as at B, to receive a circular rubber or neoprene gasket 1.

The open end of the housing is closed by meansof a heavy, circular, metal baffle 8, provided with an upstanding circumferential flange 9. This flange is drilled with a series of holes positioned for alignment with the threaded holes in the flange 4 so that the baffle may be tightly secured,

against the housing I and gasket 1 by means of bolts Ill. The baffle is provided with a plurality of chamfered-edged holes, as at II, extending over its surface.

A conventional cone type speaker I2 (such as a J enson ST-443 permanent magnet unit) is positioned within the housing I and is secured to the baffie 8 by means of bolts I3 and washers I4.

A flexible, water-proof diaphragm I5, which may conveniently be of rubber or neoprene, is

placed over the outer face of the bafiie and is secured in place between metal ring I6 (also drilled to receive bolts l0) and flange 9 on battle 8. Externally of the flexible diaphragm I5 is positioned a wire grille or screen I! to protect the diaphragm from mechanical injury. This grille is held in place by another ring I8, similar to ring l6, and is also drilled to receive the bolts I0. Thus, when the bolts are tightened, the various elements are brought tightly together and the space within the housing I is made water-tight by means of gasket 1 and diaphragm I5. A conventional water-tight stufling box I9 is provided on the housing through which leads (not shown) may be brought for connection to the speaker I2.

Another and similar form of the invention is illustrated in Figs. 3 and 4. This unit is designed to withstand greater pressures without loss of sensitivity or output than the unit illustrated in Figs. 1 and 2.

The housing I, mounting plate 2, speaker I2, and the stuffing box I9 may be identical to those on the unit shown in Figs. 1 and 2. In this unit the flange 4 on the open end of the housing is made somewhat thicker so that the bolts Ill do not extend completely through it. On the open end of the housing is a flat, metal bafiie 8, similar to the one illustrated in Figs. 1 and 2. However, instead of a, plurality of holes, it is provided with a single, centrally positioned, hole, as at 20. The speaker I2 is similarly mounted against the bafile 8, by means of bolts I3 and washers I4.

In this form of the invention, a cone-shaped plug 2| is glued in the lower end of the speaker cone. This plug should preferably be light in weight and securely bonded to the cone; it has been found that one of Lucite serves very well. In this form of the invention, a short cylinder 22 of approximately to 1" in length supports a flat, stiff, circular diaphragm 23. This diaphragm is of slightly less diameter than the inner diameter of ring I6 as shown in Fig. 4, and is provided with a series of mounting cars 24 positioned to be engaged by bolts II]. This diaing medium. A Micarta diaphragm, .01" thick;

has proven very satisfactory for this purpose.

The rod 25 is surrounded by a small circular sheet of rubber 21 which is secured to the baffle 8 around its circumference :by'ia metal "ring 28' and bolts 29 in order to prevent passage of water through the perforation in the baffle. The center of the rubber sheet is secured by means of a washer 30, fixed to the rod 25, and a small collar 3| surrounding the rod?and extending between the :washer 30 andthe diaphragm :23. This joint may :be: tightened and made water proof by tightening the nut 26--on the outer end of the rod, which seals the rubber sheet between the.

collar and the washer. n theopposite sideof the washer is positioned asmall rubber pressure seal 32 arranged and adapted to engage the baiile and seal the perforation, as :at 20. s

The assembly is completed by the provisioniof ring wand-a grille +1, and mayinclude a ring 16 as used in connection with the form shown :in Figs. v1 'and2. I 1

It is seen that the rod 25 transmitsianyzmotion of the speakercone to the diaphragm 23, whereby it effectively operates as the :speaker cone. Since water may enter the space between the hostile and. the diaphragm, there .is no pressure differential on opposite sides of the diaphragm in'order'that damage due .to high pressures is prevented. Onthe other hand, the washer .30, seal Sland rod 25 serve. asfa mechanical stop so that the pressure .difierenc'e (with reference to the space within the :housing) .is borne by" the washer and the sealb restingfagainst the :baiila. Even under maximum pressures, the diaphragm isrdisplaced for a distance equal only to the-distancehetween :bafiie. and pressure seal which may be made of the order-of 1 The rubber sheet and the seal prevent water from contacting :thespeakercone and, if the perforation in thexbafe fie is made small, even pressures corresponding to igreat depths or vproduceizlby explosions .aresn ot likely to damage the sensitive elements of the speaker IZ. i

It has been found that if the device just de scribed is mounted on the open bridge of a submarine, the passage of sound through the baflle permits it to be operated either as a speaker era microphone when the submarine is on the surface. When the submarine is submerged, no attention need be given to the speaker, as the water-tight construction of the unit prevents water from reaching the sensitive parts of the speaker, and the structure prevents damage by great pressures. Upon coming to the surface, the unit is ready for immediate operation.

Having described my invention, I claim:

1. A loudspeaker adapted to be submerged in alliquid under pressure comprising: a relatively heavy tubular housing, closed at one of its ends; a cone-type "speaker positioned in said housing,

tracing the'opemend-of said housing; a relativelyv fheavypperforated bafiie secured to the open end of r-said :hou'sing; 1a relatively stiff diaphragm, mounted externally of said perforated baffle; 'm'eans extendingthrough a perforation in said bafiie connecting the cone of said speaker to said diaphragm; and flexible means connected to said bafiie and said last mentioned means arranged and adapted to prevent the flow of said liquid therebetween.

2. In the device described in claim 1, a stop fixed to said means, extending through a perforation positioned .to engage said baffle for limiting the movement of said means extending through a perforation.

3. .A loudspeaker adapted to be submerged in a liquid. under pressure comprising: a relatively .heavy, tubular housing, closed at one of its ends; a cone-type speaker positionedninsaid housing, facing the open end Of said housing; arelatively heavy baffie havinga central perforation, secured to the open .end of saidhousing; a relatively stifi' diaphragm, mounted rexternally of .said housing; rigid means extending through the perforation in said bafile connecting thecone of said speaker and said diaphragm; and means comprising a flexible, water-proof sheet secured between said. bafile .and said rigid means.

4. In the device described in .claim 3, astop fixed to said. rigid means positioned to engage said baffle for limiting, the .movement of .said rigid means.

WILLIAM A....MYER'S.

EREEEEENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,346,226 Marlow Apr. 11, 1944 FOREIGN PATENTS Number Country Date I I 425,186 Great Britain Mar. 8,1935