DIAPHRAGM COIL AND TERMINAL SUPPORT

Patented Oct. 17, 1933

1,930,600

My present invention relates to a loud speaker of the electrodynamic type and more particularly to a new and novel mounting for the diaphragm actuating coil and the electrical connections for 5 such a speaker.

An object of my invention is to provide a new and novel support for the diaphragm of an electrodynamic loud speaker which will greatly simplify and otherwise facilitate the manufacturing

10 operations.

Another object of my invention is to provide a terminal block for the flexible leads of an adjustable diaphragm actuating coil of an electrodynamic loud speaker which will permit trans

15 verse adjustment of the coil in its air gap without interference by the leads.

Other objects and advantages of my invention will be in part evident and in part pointed out as the description proceeds.

20 In a prior patent, Number 1,886,735 issued to Edwin S. Pridham, November 8, 1932, entitled Loud speaker, and assigned to the assignee hereof, there is illustrated and claimed a loud speaker having its diaphragm actuating coil

25 mounted upon an adjustable plate by means of a flexible centering, spider. In this prior disclosure the ends of the. actuating coil, or its lead-out wires are connected to terminals carried by the speaker frame and independent of the adjust

30 able plate and as a result the lead-out wires must be secured along the diaphragm^ as shown in the above prior disclosure, or be made of a length sufficient to permit movement of the aforesaid adjustable plate.

35 A disadvantage in the above arrangement is that the leads can not be soldered to the terminals until the speaker is completely assembled.

In carrying out my invention I overcome the above objectionable features by mounting a ter

40 minal block for the diaphragm coil lead-out conductors upon the adjustable coil supporting plate. With this arrangement it is possible .to completely assemble the coil upon the support and solder the leads to the terminals before the. diaphragm

45 is attached. As a result the diaphragm is not exposed to damage when the leads are being soldered and the soldering can be carried out in a most expeditious, manner. In other words, with the elements arranged as herein disclosed the dia

50 phragm and its actuating coil can be completely assembled, connected and soldered to the terminals during the early stages of the assembly operation, and as a further result the speaker will be ready for use as soon as the parts have been

55 secured upon the electrodynamic field structure.

For a better understanding of my invention reference should be had to the accompanying drawing, wherein I have shown by way of illustration and not of limitation a proposed embodiment thereof. 60,

In the drawing;

Figure 1 is a side view of a loud speaker with parts broken away and in section to illustrate the relative position of the various elements,

Figure 2 is a plan view of a diaphragm actuat- 65 ing coil and its adjustable centering plate with the terminal block mounted thereupon,

Figure 3 is a vertical sectional view of the diaphragm coil and supporting plate taken along line Ill-r-III of Figure 2, looking in the direction 7Q of arrows, and

Figure 4 is a fragmentary front view of the terminal block illustrated in Figures 2 and 3 of the drawing.

In the drawing the numeral 10 designates a 75 field frame of the U type, as distinguished from the "Pot" type, and the numeral 11 designates a central pole which is secured centrally between the ends of the frame 10. Extending across the ends of the frame. 10 there is a fiat frame member 80 12 which has a central aperture 13. The aperture 13 is slightly larger than the diameter of the central pole 11 and in conjunction therewith it provides an annular air gap 14 in the magnetic field structure. Mounted upon and extending 85 outwardly from the. frame member 12 there is a diaphragm housing or support 15 and attached at its rim to this housing 15 there is shown a diaphragm 16. When the diaphragm 16 is completely assembled it is provided.with a cylindrical 90 coil support 17 having an actuating winding, 18. After the speaker is assembled, as illustrated,, the cylindrical coil support 17 and the. winding 18 are centered concentrically in the air gap 14 by means of a flexible centering device or spider 19 and 95 . the ends of the winding 18 are provided with suitable flexible conductors 20 which, lead to an external circuit, such as a radio set or the like.

In the present instance the flexible centering spider 19 is mounted upon a plate 21 which is 100 adjustably secured upon the outer frame member 12. The purpose of this adjustable plate 21 is to permit a proper positioning of the winding 18 in the air gap 14.. As here illustrated, the adjustability of the plate 21 is accomplished by pro- .105 viding holes for the screws,'which secure it to the frame member 12, that are larger than the screws. This will permit a sufficient movement of the plate 21 to center the winding. 18 in the air gap, after which the' securing screws can. be 110

tightened to hold the plate securely in its final position.

If the winding 18 is to he properly centered and held in this position throughout its useful life, 5 it is important that no strain or tension be exerted upon the coil support 17 by the flexible conductors 20 which connect with the external circuit. It is also important that the flexible conductors 20 exert as little retarding force to the axial move

10 ment of the diaphragm as is possible.

It will be evident from the above that if the conductors 20 are to be secured to an independent stationary terminal block they will have to be long enough to permit a maximum adjustment

15 of the plate 21 from the terminal block. In providing conductors 20 of sufficient length to permit this adjustment it will also be necessary that the conductors be not too long, otherwise they will vibrate and strike other parts of the

20 speaker. If the conductors 20 strike adjacent parts of the speaker they will introduce noises extraneous to the sound reproduced by the diaphragm and if, as assumed in the former case, they should not be of sufficient length to permit

25 a maximum adjustment of the plate 21 they will be put under tension and thus exert a strain upon the diaphragm which will interfere with its proper reproduction of sound.

By my invention I overcome the above disad

30 vantages and also greatly simplify the assembling operation by mounting a terminal block 22, for the conductors 20 and the external circuit, directly upon the adjustable plate 21. With this arrangement the terminal block 22 will always be

85 located the same distance from the winding 18, irrespective of its adjustment in the air gap 14, and as a result the flexible conductors 20 can be cut to a definite and proper length for all positions of adjustment of the winding 18 in the air

40 gap 14.

As illustrated in the drawing, the terminal block 22 is mounted in a vertical position upon a flange 23 formed upon the plate 21 and is provided with suitable terminals 24 to which the

45 external circuit and the coil conductors 20 can be connected.

When the coil support 17 with its winding 18 and the terminal block 22 with its terminals 24 have been assembled, as illustrated in Figures

50 2 and 3 of the drawing, the conductors 20 can be soldered in place and the parts so assembled can be handled as a unit of the speaker assembly.

The terminals 24 are illustrated as having thenupper ends offset and disposed in spaced relation

55 with the terminal block 22. This disposition of the ends of the terminals is for the purpose of permitting them to be conveniently bent away from or toward the terminal block should the flexible conductors be found too long or too short

60 after the soldering operation. In other words, with this type of terminal it will be possible to bend the ends outwardly, as illustrated by dot and dash lines in Figure 3 of the drawing, should the conductors 20 be too slack after the solder

65 Ing operation. On the other hand, should the flexible conductors 20 be under too much tension after the soldering operation they can be slackened by bending the ends of the terminals inwardly toward the winding 18. This feature is

<T> an important one as it provides for a simple, and convenient adjustment of the flexible conductors 20 to a proper. slackness without unsoldering same.

After this unit has been assembled the next ?5 operation will be to affix the diaphragm to the

coil support. This can be done by gluing the diaphragm to the coil support in any suitable manner.

When the diaphragm 16 has been affixed to the above described coil assembly and secured at its 80 rim to the housing 15, the winding 18 can be centered in the air gap 14 and there secured in place. After the above parts have been assembled, the speaker can be operated by merely connecting an external signal current circuit to the 85 terminals 24 and supplying an energizing current to the magnetic field coil 25, which is shown surrounding the central pole 11.

Now, should an adjustment of the winding 18 in the air gap 14 become necessary, either dur- 90 ing the assembling operation or thereafter, this can be accomplished without disconnecting the conductors 20 from the terminals 24, as these terminals will move with the winding 18 and avoid any possibility of the conductors 20 inter- 95 fering with a proper operation of the diaphragm 16 in any position to which it may be adjusted.

A further advantage obtained by my invention is that the flexible conductors 20 which connect , with the diaphragm actuating winding or moving 100 coil 18 will be of a minimum length and therefore will not add any appreciable weight to the moving element of the speaker. -•

While I have, for the sake of clearness and in order to disclose my invention so that the same 105 can be readily understood, described and illustrated a specific device and arrangement, I desire to have it understood that this invention is not limited to the specific means disclosed but may be embodied in other ways that will suggest 110 themselves, in view of this broad disclosure, to persons skilled in the art. It is believed that this invention is broadly new and it is desired to claim it as such so that all changes as come within the scope of the appended claims are to be'US considered as part of this invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is—

1. In an electrodynamic loud speaker, the com- . bination of a magnetic field structure having an 120 annular air gap, a diaphragm having an actuating coil disposed in said air gap, an adjustable support for said actuating coil, whereby the coil may be adjusted to a concentric position in said air gap, and terminals carried by and movable 125 with said adjustable support to which said diaphragm actuating coil is connected.

2. In an electrodynamic loud speaker, the combination of a magnetic field structure having an . annular air gap, a diaphragm having an axially 130 movable actuating coil disposed in said air gap, a laterally adjustable support for said actuating coil, whereby the coil may be adjusted to a concentric position in said air gap, terminals carried by said adjustable support to which an ex- 135 ternal circuit may be connected, and flexible conductors connected between said terminals and said diaphragm actuating coil.

3. In a loud speaker, the combination of a j^g magnetic field structure having an annular air gap, a diaphragm actuating winding disposed

in said air gap, a flexible centering spider for said winding adapted to permit axial movement thereof in said air gap, a laterally adjustable sup- 145 port for said flexible centering spider mounted adjacent said air gap, said adjustable support having an insulating terminal block mounted thereupon, terminals on said terminal block, and flexible conductors permanently secured between 150

said terminals and the ends of said diaphragm actuating winding.

4. In a loud speaker, the combination of a magnetic field structure having an annular air

5 gap, a diaphragm actuating winding disposed in said air gap, a flexible centering spider for said winding adapted to permit axial movement thereof in said air gap, a laterally disposed support for said flexible centering spider adjustably mount

10 ed adjacent said air gap, said laterally disposed support having an upturned flange at one side thereof, an insulating terminal block secured to said flange and projecting clear of said magnetic field structure, terminals upon said terminal block,

15 and flexible conductors permanently secured between said terminals and the ends of said diaphragm actuating winding.

5. In a loud speaker, the combination with a diaphragm having an actuating winding disposed

20 in the air gap of an electromagnetic field structure, of a centering device for said winding comprising a transversely disposed flexible member secured at its central portion to said diaphragm and mounted at its outer extremities upon a sup

25 port adjustably secured with respect to said air gap, flexible conductors extending from said actuating winding, and a terminal block mounted upon said support and movable therewith having terminals to which said flexible conductors are

30 connected.

6. In an electrodynamic speaker, the combination of a truncated conical diaphragm having a cylindrical coil support secured at the open end thereof, a transversely disposed flexible center

35 ing spider for said coil support, a plate like member adapted to be secured upon a magnetic field structure for supporting said flexible centering spider, a terminal block carried by said plate like member having suitable terminals, a winding

d,- upon said coil support having its ends terminating upon said support, and flexible conductors connected between the ends of said winding and the terminals upon said terminal block.

7. In an electrodynamic speaker, the combina45 tion of a truncated conical diaphragm having a

cylindrical coil support secured at the open end thereof, a magnetic field structure having an air gap, a transversely disposed flexible centering spider secured to said coil support, a plate like mem52 ber adapted to be secured upon said magnetic field structure for supporting said flexible centering spider, a terminal block having suitable terminals carried by said plate like member, a

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diaphragm actuating winding upon said coil support, flexible conductors connected between the ends of said winding and the terminals upon said terminal block, and means for adjustably securing said plate like member upon the magnetic 80 field structure, whereby said winding and its flexible conductors may move as a unit when the winding is being centered in said air gap.

8. In an electrodynamic loud speaker, the combination of a magnetic field structure having 85 an annular air gap, a diaphragm having an axially movable actuating coil disposed in said air gap, a laterally adjustable support for said actuating coil, whereby the coil may be adjusted to a concentric position in said air gap, terminals go carried by said adjustable support to which an external circuit may be connected, flexible conductors connected slackly between said terminals and said diaphragm actuating coil, and means whereby said terminals may be adjusted to deter- 95 mine the slackness of said conductors.

9. In a loud speaker, the combination of a magnetic field structure having an annular air gap, a diaphragm actuating winding disposed in said

air gap, a flexible centering spider for said wind- 100 ing adapted to permit axial movement thereof in said air gap, a laterally adjustable support for said flexible centering spider mounted adjacent said air gap, said adjustable support having an insulating terminal block mounted thereupon, 105 terminals on said terminal block, flexible conductors permanently secured between said terminals and the ends of said diaphragm actuating winding, and means whereby said terminals may be adjusted to provide a definite slackness in said Hq conductors after they are secured in place.

10. In a loud speaker, the combination with a diaphragm having an actuating winding disposed in the air gap of an electrodynamic field structure, of a centering device for said winding com- 116 prising a transversely disposed flexible member secured at its central portion to said diaphragm and mounted at its outer extremities upon a support which is secured upon the field structure, flexible conductors extending from said actuating 12o winding, and a terminal block mounted upon said support having terminals to which said flexible conductors are connected, said terminals having projecting ends that can be bent to provide the required slackness in said conductors after 125 they have been connected to the terminals.

RAY E. TOLERTON.

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