US1696235A - Loud-speaker unit - Google Patents

Description

Dec; 25, 1928.

H. HELLER ET AL LOUD SPEAKER UNIT Filed Dec. 2, 1926 INVENTOR ,07 QW w Wy ATTORNEY I Patented Dec, 25,1928.

{UNITED-(STATES PATENT OFFICE.

ntrco HELLER AND O. MITCHELL, OF MILWAUKEE, WISCONSIN, ASSIGNORSTO A. C. KOOTZ, OFMILWAUK EE, WISCONSIN.

LOUD-SPEAKER UNIT.

Application filed December 2, 1926. Serial No. 152,111.

This invention relates to improvements in loud speaker units.

through from the armature to the diaphragm.

It is a further object of the invention to provide a novel and improved means for mounting the spool which carries the influencing coil between the poles of the permanent magnet, the pole pieces being utilized to facilitate-the quick assembly of the spool between the pole pieces and within the magnet.

In the drawings:

-, Figure 1 is 'a vertical axial section through the housing of a loud speaker unit, showing in side elevation the mechanism embodying this invention.

Figure 2 is a plan view of the mechanism as it appears when the dust cap is removed from the housing.

Figure 3 is an elevation of the mechanism as viewed from the right in Figure 1, the

, pole pieces.

Like parts are'identified by the same reference characters throughout the several views.

This is a companion to our application,

' Ser. No. 152,112, filed Dec. 2, 1926, in which we have disclosed and claimed the particular diaphragm mounting shown in the accompanying drawings, wherein the two parts 5 and6 of the housing are held together by screws 7 to enga e clampingly an annular rubber cushion 10 having a channel in its inner periphery engaged about the mar 'n of diaphragm 11. .T ie mechanism for actuating the diahragmis enclosed by a removable ca 12 i rictionally en aged about the perip cry of diaphragm ousing member 6 and secured thereto, if desired, by screws 13.

. The housing member 6 comprises a mountingplate uponwhich the entire operating mechanism is assembled. Ithe as sem bly of the operating mechanism is unitary in the sense that the permanent magnet 15 is the only part which is actually connected with the mounting plate, all other mechanism being carried thereby.

In order to fix the position of the permanent magnet on the mounting plate, we have found it convenient to provide the mounting plate with integral bosses 16,17, and 18. Magnet 15 is of the ordinary horseshoe type, and it is disposed with one of its legs fiat in contact with the non-magnetic mounting plate 6. Bosses 17 and 18 are disposed upon either side of the legand approximately in contact therewith while the end of the magnet leg abuts the boss 16. Bosses 17 and 18 are of slightlyless height than the thickness of the magnet leg which they embrace. This makes it possible to secure the magnet rigidly in place by spanning it with a dielectric strap 19. Any nonmagnetic substance might conveniently be used for this strap but for the fact that it is also desirable to use the strap as a carrier for the binding posts 20. For this purpose the strap is provided with forwardly extending arms at 21 in which the binding posts are fixed.

Between the poles of the horseshoe magnet 15 are the pole pieces 25 and an influencing coil 26 with which an armature 27 is assembled. The-armature is connected by a link 28 with diaphragm 11. Thelocation of the magnet is such that it is necessary to provide a hole at 29 through which link 28 passes in a direct line between the armature and diaphragm.

The structure hereinafter to be described is such as to make it possible for the magnet to be fixed to the mounting plate 6 as the first step in assembling the loud speaker unit. The spool 26 upon which the influencing coil 30 is wound may conveniently be made of bakelite or other dielectric or non-magnetic material and is provided with holes for the leads 31 which connect coil 30 to thebinding posts 20. The 'ends of the spool are preferably recessed at 32 and provided with shoulders at 33 against which the pole pieces may abut to define their spacing accurately with reference to the armature 27 which projects from the end tangular plate adapted to bedisposed in face contact with the inner surface of the magnetic pole. From opposite sides of the plate flanges 35 depend in engagement with the spool 26, while from the other sides of the plate similar flanges 36 project upwardly or downwardly, as the case may be, and en brace the pole in the magnet. Figure 4 shows one pole piece assembled with the spool, the flanges being engaged with the ends of the spool. and flanges 36 being adapted to embrace one pole of the magnet. The other pole piece 25 is illustrated in a position for application to the spool in like manner. It will be obvious that when both pole pieces are assembled on the spool it is possible to push the entire assembly over the boss 16 and between the poles of the magnet, where the assembly will preferably fit very closely and will be trictionally retained by a certain amount of spring or resiliency in the magnet.

In order to complete the device it is only necessary to connect the link pin 28 from armature 27 through hole 29 to the diaphragm 11 and to connect the leads 31 to the binding posts 20. The mechanism will now be conn pletely operative, since the thickness of tongues 33 accurately definesthe spacing between the opposing flanges 35 of the two pole pieces 25 and the armature 27 is accurately centered between the pole pieces during the operation, whereby it is connected to link pin 28.

It will be obvious that this device lends itself to ready assembly and disassembly and to accurate and economical manufacture. The objects of the invention are, therefore, satisfie We claim:

1. A device of the character described including a mounting plate provided with bosses, a magnet having a leg disposed between said bosses, and a strap spanning said leg from one boss to another and connected with said bosses, said leg being confined between said plate and strap, whereby to secure said magnet to said plate.

2. In a device of the character described, the combination with a mounting plate, of a magnet having a leg disposed in contact therewith, and a strap connecting said magnet leg with said plate and provided with arms carrying binding posts, said leg being confined between said plate and strap.

3. In a device of the character described, the combination with a mounting plate provided with laterally spaced bosses and a third boss ofiset from a point between said first mentioned bosses, of a magnet having a leg disposed between said spaced bosses and abutting said third boss, and a tie strap extending across the leg of said magnet and fixed to said first mentioned bosses.

4. In a device of the character described, the combination w h a mounting plate provided with laterally spaced bosses and a third boss oil'set from a point between said first mentioned bosses, of a magnet: having a leg disposed between said spaced bosses and abutting said third boss, and a tie strap extending across the leg of said magnet and fixed to said first mentioned bosses, said tie strap having forwardly projecting arms carrying binding posts, together with an iniluencing coil associated with said magnet and provided with leads connected to said binding posts.

5. The combination with a housing, and a diaphragm operativcly mounted therein. of a set of positioning bosses on a portion of said housing, a magnet having an apcrtured leg abutting said portion and confined between said bosses, an armature within said magnet, and a link extending through the aperture of the leg of said magnet from said armature to said diaphragm.

(3. The combination with a. diaphragm housing and a diaphragm operativcly mounted therein, of a set of spaced bosses at the rear of said housing. a horseshoe magnet having an apertured leg abutting said housing and confined lJllWQtll said bosses, a. dielectric strap member spanning two of said bosses across the aperturcd leg of said magnet and fixed to said bosses, whereby to secure said magnet to said housing, an influencing coil mounted on said magnet between the poles thereof and provided with an armature, a link connecting said armature operatively with said diaphragm through the hole in the leg of said magnet, binding posts supported from said strap, and leads from said coil to said binding posts.

7. The combination with a pair of spaced magnetic poles, of :2V spool receivable between said poles, and pole pieces detachably engageablc with said spool and with respective poles, said spool and pole pieces being adapted to be introduced between said poles as a unit in sliding engagement therewith.

8. The combination with a pair of spaced pole members, of a spool provided in its ends with recesses, and tongues adapted to limit the approach of upper and lower pole pieces in said recesses, together with pole pieces having inwardly extending spool engaging portions receivable in said recesses' and outwardly extending portions adapted to embrace said pole members.

9. As a new article of manufacture, a pole piece having an approximately reotangular central portion, with o posite depending flanges on two sides, an upwardly extending flanges on the other two sides.

10. In a device of the character described the combination with a mounting plate and a horseshoe magnet having one leg abutting said mounting plate and connected therewith, of an influencing coil between the diaphragm 6 'ing therefromthrough the ends thereof at substantially the level of said tongues, and pole pieces provided with flanges embracing the ends of said spool and spaced from the flan'gesof each other by said tongues at 10 either side of said armature 11. In a device of the character described,

the combination with a mounting plate and a horseshoe magnet havingone leg abutting said .mounting plate and connected there- 15 with, of an influencing coil between the poles (provided with upper and of said magnet a spool for said coil having its ends rovided with 'upper and lower recesses an intermediate tongues, an armature mounted in said spool and projecting therefrom through the ends thereof at substantially the level of 'said tongues, and pole pieces provided with flanges embracing the ends of saidspool and spaced from the flanges of each other by said tongues at either side of said armature, each of said pole pieces having another pair-of flanges at right angles to the first and embracing the poles of said magnet.

I HUGO HELLER.

. JOHN C. MITCHELL.

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