US1759725A - Sound-producing device - Google Patents

Description

y 1930- A. P. YOUNG ET AL SOUND PRODUCING DEVICE Filed Aug. 7, 1928 Inventors: ATthuT PYoung Joseph Hutt,Deceased. Cecilia Elizabeth Huttjxecutrtx,

Their Attorneg.

Patented May 20, 1930 UNITED STATES PATENT OFFICE ARTHUR PBIHROSE YOUNG, OI KENILWORTH, ENGLAND, AND JOSEPH HUTT, DE- CEASED, LATE OF KENILWORTH, ENGLAND, BY CECILIA ELIZABETH HUTT, EXECU- TBIX, OI KENILWOBTH, ENGLAND, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A

CORPORATION OF NEW YORK SOUND-PRODUCING DEVICE Application filed August 7, 1926, Serial No. 298,056, and in Great Britain September 22, 1927.

Our invention relates to sound producing or like devices for producing electrical oscillations corresponding to original sound waves or equivalent mechanical vibrations.

It relates particularly to such devices as are provided with a hollow diaphragm, which is sutiiciently rigid to move substantially as a whole, at any rate at frequencies up to approximately 2000 cycles per second, for example, saucer-shaped, cone-shaped diaphragms, or diaphragms shaped like the frustum of a cone. When such diaphragms carry at their smaller ends operating means such as an operating coil arranged to move in a narrow air-gap in a magnetic circuit, there may be a tendency for the diaphragm to operate slightly non-axially in a manner to cause the operating member to foul the edge of the air-gap. This disadvantage arises more particularly in cases in which the movable element of the device is very flexibl supported so that it will have a relatively lbw natural periodicity.

It is the object of the present invention to provide a construction in which this disadvantage will be obviated, and the present invention involves connecting the larger end of the diaphragm by flexible means which is adapted and arranged to prevent transverse movement, but to allow axial movement of the diaphragm without appreciably deforming the same, whereby the diaphragm ma operate in true piston fashion.

ur invention will be better understood from the following description when considered-in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

Referring to the drawings, Figs. 1 to 3 illustrate various details of aloud speaker or sound producer constructed in accordance with our invention.

In the illustrated arrangement, according to the invention, the larger end of a diaphragm 1 is supported by a connecting member 2 having over-lapping staggered slots 3. Preferably, this member is in the form of a ring, the lane of which is transverse to the main axis of the diaphragm, the ring being arranged outside the diaphragm and connected to the diaphragm at the edge of the latter. The outer end of the ring may be gripped in the usual manner in any suit-- able way.

\Ve also consider that it is advisable to support this type of diaphragm at its smaller end by means of a member 4 provided with overlapping slots 5 similar to those of the outer support member 2. The slots of the inner and outer connecting members may be longitudinalor arcuate holes, the long axes of which are perpendicular to the respective radii. The inner connecting member is preferably fixed at its contact to the pole piece (3 by means of a bolt 7. We have used with gldvantage fibredor making the ring and the \Vhen the outer edge of the diaphragm is mounted in a hole in a bafiie or sound-board 10, which is preferably used in place of a sound-horn in order to increase the output from the diaphragm by reducing the angle of radiation without introducing any material resonant effect, a further feature, according to the invention, involves the use of means such as soft cotton wool washers 8 for obviating the effect of the slots aforesaid in the member supporting the larger end of the diaphragm on the acoustical eiiect of the sound-board. These washers preferably cover the slots, are lightly packed between the extensions 9 of the battle-board or support, and are arranged to overlap the ring on either or both sides thereof with sufiicient clearance to permit axial movement of the diaphra m.

It will of course be apparent to those skilled in the art that an operating coil 11 is attached to the inner edge of the diaphragm 1 and is arranged to move in the air-gap between the pole pieces 6 and 12 of a field magnet of any suitable type.

What we claim as new and desire to secure by Letters Patent of the United States is 1. The combination of a support, a diaphragm, and a member connected between said support and said diaphragm and provided with overlapping staggered slots.

2. The combination of a support, a diaphragm, and a member connected between said support and said diaphragm and provided with overlapping staggered slots substantially parallel With the periphery of said diaphragm. 3. The combination of a support, a (11- aphragm, and a member connected between said support and said diaphrgam and provided with overlapping staggered slots, and means for supporting a flexible member ad jacent said slots.

. 4. The combination of a support, a diaphragm, and a member connected between said supportand said diaphragm and'provided with overlapping staggered slots, and 15 means for supporting a cotton Wool Washer adjacent said slots.

5. The combination of a pair of support members, a diaphragm having inner and outer peripheries, a member provided with overlapping staggered slots and connected between one of said support members and the inner periphery of said diaphragm, and a like member connected between the other of said supports and the outer periphery of said diaphragm.

In Witness whereof, we have hereunto set our hands this eleventh day of July, 1928.

ARTHUR PRIMROSE YOUNG, CECILIA ELIZABETH HUTT,

Eirecutriaz of Joseph Hutt, Deceased.

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