US1948361A

US1948361A - Sound reproducer

Info

Publication number: US1948361A
Application number: US209467A
Authority: US
Inventors: Sigurd A Sollie
Original assignee: Federal Telegraph Co
Current assignee: Federal Telegraph Co
Priority date: 1927-07-30
Filing date: 1927-07-30
Publication date: 1934-02-20
Anticipated expiration: 1951-02-20

Description

20, 1934- s. A. SOLLIE 8,36

SOUND REPRODUCER Filed July 30. 1927 4 Sheets-Sheet l INVENTOR.

ATTORNEY 3934* s. A. SOLLiE-Z 1,943,361

SOUND REPRODUCER Filed July 30, 1927 4 Sheets-Sheet 2 .314. 50 Z Z (J6 Feb. 20, 1934. SQLLIE SOUND REPRODUCER Filed July 30. 1927 4 Sheets-Sheet 4 INVENTOR. ,5%' JJA 50 2226;

mTTORNEY Patented Feb. 20, 1934 UNITED STATES SOUND REPRODUCER Sigurd A. Sollie, Palo Alto, Calif., assignor to Federal Telegraph Company; San Francisco, Calif., a corporation of California Application July 30, 1927. Serial No. 209,467

8 Claims.

My invention relates broadly to power speakers and more particularly to aloud speaker of the conical shaped diaphragm type.

One of the objects of my invention is to provide a power speaker of simplified design capable of manufacture and production inexpensively on a quantity production scale.

Another object of my invention is to provide a power speaker of the conical shaped diaphragm type having parts which may be conveniently manufactured in unit assemblies for assembly in a completed cone speaker under requirements of minimum skill and the expenditure of minimum labor.

Still another object of my invention is to provide a conical shaped sound reproducing diaphragm construction which may be assembled compactly with respect to an electromagnetic driving system for impressing sound vibrations upon the conical shaped sound reproducing diaphragm.

A further object of my invention is to provide a construction of frame for a conical shaped sound reproducing diaphragm wherein the parts may be stamped or pressed from sheet metal and assembled in a mounting for mechanically protecting a conical shaped sound reproducing diaphragm and suspending the diaphragm with respect to an electromagnetic driving system.

Other and further objects of my invention will be understood from the specification hereinafter following by reference to the accompanying drawings, wherein:

Figure 1 is a perspective view partially broken away and illustrated in cross-section showing the assembly of parts in the cone speaker of my invention; Fig. 2 is a rear view of the assembled cone structure of my invention preparatory to the coupling of the cone structure to the driving apparatus; Fig. 3 is a front view of the cone structure of my invention; Fig. 4 is an end view of the cone mounting structure showing the arms which extendto the electromagnetic driving apparatus broken away; Fig. 5 illustrates the electromagnetic driving mechanism and cone suspension of my invention arranged preparatory to the assembly process of the cone suspension to the magnetic housing; and Fig. 6 is a perspective view illustrating the construction of the coupling device and coil support which is disposed between the conical shaped sound reproducing diaphragm and the electromagnetic driving mechanism.

My invention is directed to a practical construction of conical shaped sound reproducing diaphragm and electromagnetic driving system of the general class illustrated. in Letters Patent #1,637,119 to Frederick A Kolster and Sigurd A. Sollie, dated July 26, 1927, reissued on Sept. 1'1, 1928 as No. 17,086.

The conical shaped sound reproducing diamember is arranged to carry the entire cone mounting including a protective pressed metal frame which provides a carrier for a device for damping the peripheral edge of the diaphragm. The entire magnetic plate member is arranged to be coupled to the field magnet of the electromagnetic driving system providing a concentrated path for magnetic lines to a central core member which projects through an aperture formed in the plate member and provides a magnetic gap into which a bobbin supported from the sound reproducing diaphragm is arranged to project. The variable currents from a power amplifier system are passed through the bobbin and react with the permanent magnetic field for impressing vibrations upon the conical shaped sound reproducing diaphragm.

Referring to the drawings in more detail, reference character 1 designates the conical shaped sound reproducing diaphragm suspended by means of membrane 2 in a plane intermediate the apex and peripheral edge of the sound reproducing diaphragm. A ring support 3 is provided over which the membrane 2 is stretched and secured in position by means of ring member 4. A plate member 5 of magnetic material is arranged to receive the ring structure 3 which is retained thereon by any suitable means, as, for example, the screw members 6. The plate member 5 is centrally apertured at 8 for receiving the coil support 9 which extends from the conical shaped sound reproducing diaphragm'l and is connected thereto by means of coupling member 11. A winding 10 constituting a bobbin or variable current carrying coil is disposed upon the coil support 9. The plate member 5 is provided with a plurality of diametrically opposite flattened portions 12 with alternately positioned lug members 14. Pressed metal arms 15 are secured by means of screw members 16 to the flattened portions 12 on plate member 5 and extend forward at an angle from the plate 5 and are secured at 17 to a channel shaped ring member 19 having an inturned edge portion 20 thereon. The channel shaped ringmember 19 may be stamped or pressed from sheet metal and by reason of its cross-section structure, provides a frame of substantial mechanical strength for protecting the parts of the conical shaped sound reproducing diaphragm. An oppositely directed channel shaped ring member 21 is secured to the ring member 19 by means of rivets 22. The oppositely directed channel shaped ring member 21 provides a pocket for receiving a felt pad 23. A flexible sheet of material 24 extends between the channel shaped

members

19 and 21 and is connected to the peripheral edge 25 of the conical shaped sound reproducing diaphragm 1 providing means for damping the edge of the cone for preventing blasting, weaving, fluttering, rattling or the setting up of other noises inherent in a cone structure which is suspended from a position remote from the periphery.

The magnetic plate member 5 is shaped to enter the annular recess 29 in the magnetic casing 26 within which is arranged the electromagnetic winding 27 constituting the field of the power speaker. A central pole piece 30 passes through the electromagnetic winding 27 and is cut away at 31 enabling the sound reproducing diaphragm l to closely conform with the shape of the pole piece. The coil support 9 extends between the magnetic gap formed between the pole piece 30 and the magnetic plate member 5. The magnetic plate member 5 is secured to the casing 26 by means of lugs 28 on the casing 26 which coincide with the lugs 14 on plate member 5, the

lugs

14 and 28 being secured by means of bolt members 29. The channel shaped ring member 21 provides a seat for the felt pad 23 which may be pressed into surface engagement with a suitable baffle board or panel 18 for closing the gap be tween the front of the cone and the rear of the cone and thereby improving the acoustic properties thereof. The damping ring member 24 may be divided into the segments represented at 24a, 24b and 240 in Fig. 3 for facilitating the assembly of the apparatus. It will be observed that the sound reproducing apparatus of my invention is particularly adapted for unit assembly operation. That is to say, the ring structure 3 with its suspending membrane 2 provides a simple assembly. The connection of the ring structure 3 with the magnetic plate 5 is readily accomplished. The securing of the frame structure including the

ring members

19 and 21 and arms 15 is an extremely simple process. Thereafter, the insertion of the complete cone assembly with respect to the electromagnetic driving mechanism is simply a matter of bolting the magnetic plate member 5 in proper position with respect to the housing 26.

The construction of the power speaker in accordance with my invention has been found to be extremely practical and successful in its operation, and while I have described a certain perferred embodiment of my invention, I desire that it be understood that modifications may be made and that no limitations are intended other than are imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A sound reproducer comprising a casing, a conical shaped sound reproducing diaphragm, means for suspending said diaphragm from said casing in a position intermediate the apex and peripheral edge of said diaphragm, and a pair of channel shaped ring members secured back to back, means carried by said ring members and in contact with said peripheral edge of said conical shaped sound reproducing diaphragm for supporting the edge of said diaphragm.

2. An acoustic device comprising a diaphragm, a frame surrounding and supporting said diaphragm, fiexible means attaching said diaphragm to said frame and preventing the free passage of sound waves therebetween, means for actuating said diaphragm, a baille wall adjacent said frame, and a gasket of resilient sound absorbing material inserted between said frame and baille wall whereby the transmission of sound waves between said frame and baille wall is prevented.

3. In a sound reproducer, a bafile board, a tympanum, a peripheral supporting structure for said tympanum, and a member of resilient sound insulating material cooperating with said supporting structure and said baffle board to form a closure around the peripheral edge of said tympanum whereby the passage of sound waves between said tympanum and said baflle board is restricted.

4. In a sound reproducer, the combination with a tympanum of a supporting structure therefor, said supporting structure comprising a rim from which the periphery of said tympanum is supported, means completely closing the space between said tympanum and said rim, and a ring of resilient, sound absorbing material secured to the face of said rim for engaging a battle board.

5. In a sound reproducer, the combination with a conical tympanum of a supporting structure therefor comprising a rigid rim about the periphery of the tympanum, a flexible member attaching the tympanum to the rim and completely closing the space therebetween, a channel in the face of said rim and a ring of resilient, sound absorbing material secured in said channel.

6. The combination with a baffle board having an opening through which sound waves are to be propagated, a tympanum of the non-planar type cooperably associated with said opening and operable to propagate sound waves therethrough, a supporting structure for said diaphragm said supporting structure including a member circumscribing the periphery of said diaphragm, and a compressible resilient sealing ring carried by said member, said sealing ring functioning substantially to close the joint between said tympanum and said bafiie board.

7. The combination with a baflie board having an opening through which sound waves are to be propagated, a tympanum of the non-planar type cooperably associated with said opening and operable to propagate sound waves therethrough, a supporting member for the peripheral portion of said diaphragm and a compressibly resilient member interposed between said supporting member and said bafiie board for restricting the passage of sound waves directly around the peripheral edge of said diaphragm.

8. The combination with a baffle board having an opening through which sound waves are to be propagated, a tympanum of the non-planar type cooperably associated with said opening and operable to propagate sound waves therethrough, a ring of channel-shaped cross section circumscribing the periphery of said diaphragm, a felt sealing ring carried by said first mentioned ring, and flexible suspension means interposed between said first mentioned ring and the peripheral portion of said diaphragm, said suspension means operable to support the peripheral portion of said diaphragm and at the same time close the joint between the diaphragm and said first mentioned ring, said sealing ring functioning to close the joint between said first mentioned ring and said bafiie board.

SIGURD A. SOLLIE.