US1918366A

US1918366A - Horn structure

Info

Publication number: US1918366A
Application number: US576049A
Authority: US
Inventors: Alexander I Abrahams
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-11-19
Filing date: 1931-11-19
Publication date: 1933-07-18
Anticipated expiration: 1950-07-18

Description

A. ABRAHAMS 1,918,366

HORN STRUCTURE July 18, 1933.

Filed NOV. 19. 1931 I INVENTOR BY M M ATTORNEYS Patented July 18, 1933 UNITED STATES PATENT OFFICE ALEXANDER I; ABRLHAIS, OF NEW YORK, N. Y.

HORN s'rauc'ruim Application fled November 19, 1981. Serial No. 579,049.

- vide a horn which is'capable of radiating sound, at its mouth, in an annular direction. A feature of the invention resides in an acoustic horn which has on the interior thereof a baflle to provide the horn with an annular. sound conducting path.

Another feature of the invention relates to a horn having positioned in the mouth thereof a plug or baflle corresponding in curvature to the curvature of the horn.

Another feature of the invention resides in an acoustic horn having an annular sound chamber throughout a portion of its length, and having a substantiall cylindrical mouth.

A further feature of t e invention resides in a novel sound chamber which may be attached to conventional horns for substantial ly eliminating the directional effect of the latter.

A further feature relates to the organiza- 39 tion and arrangement of elements which go sideration of the following detail descriptions and the appended claims.

Referring to the drawing:

Fig. 1 shows in sectional view a horn struc ture according to the invention;

40 Fig. 2 is asectional view of the horn of.

Fig. 1, taken along the line 2-2 thereof;

Fig; 3 is an enlarged view of the manner of supporting and spacing the internal and external walls of the born;

Fig. 4 is a partial sectional view of a modified manner of using the horn of Fig.1.

Referring more particularly to Fig. 1, the

numeral 1 represents the outer wall of the horn according to the invention. The mem- 5 ber 1 may be constructed of any suitable material such as wood, fiber, impregnated paper or the like, and preferably although not necessarily, manufactured in accordance with the method disclosed in application 'Serial No. 565,297. As shown in the drawing the wall section 1 is of'tapered cross section and in this respect is similar to horns of the conventionaltype. However, in order to achieve the full advantages of the invention it is preferred, although not necessarily, to design the mouth of the horn so that its outer circumferential edge is at a right angle with respect to the longitudinal axis of the horn, so that the sound issuing from the horn is directed in a path substantially perpendicular to the main air column. It will be understood, of course, that the horn section 1 will be designed in accordance with the conditions of use to which the horn is to be put, and while one particular ratio between the large and small ends of the horn is shown, it will be understood that the invention is not limited thereto. and that any other desired ratio may be employed.

For the purpose of providing a horn with a substantially annular sound chamber there is positioned within the wall member 1, and in spaced relation thereto, a plug or baflle 2, the curvature of which conforms in a general Way to the curvature of the wall section 1. However it will be understood that this latter feature is not absolutely necessary and the member 2 may have any curvature depending upon the taper that is desired in the actual sound column.

However, it is preferred to design the member 2 so that the outer circumferential edge is substantially parallel to the edge of the member 1, so that there is produced in effect a substantially cylindrical sound emerging passage. If desired the member 2 may itself be hollow so as to take advantage of any radiating properties of the material 2. On the other hand, under certain conditions it may be desirable to eliminate direct radiation along the axis of the horn, in which event the member 2 would preferably be of a solid material, or at least if it is hollow its open end may be provided with a plug or bafile to oon- 1 I 4 4AM A A trol the soundthat may be directly radiated from the wall 2.

For the purpose of supporting and spacing the members 1, 2, in.a fixed relation there is provided a tapered plug or ferrule 3 which is attached to a ring 4, as shown clearly in Figs. 2 and 3 of the drawing. The upper end of the ferrule 3 is hollowed out preferably to con,- form to the tapered point of the wall section 2, and if desired the member 2 may be rigidly held in the ferrule 3 by a suitable cement, by screws, or in any other convenient manner so as to maintain the section 2 at the proper spacing with respect to member 1. i

As will be apparent from Fig. 2, the ring 4 is provided with a set of spokes 5' on which is supported the ferrule 3. The ring 4 is provided with a flange 6 which is adapted to fit within the constricted end of the horn section 1, as clearly shown in Fig. 1 of the drawing. For the purpose of maintaining the flared ends of the sections 1 and 2 in the proper spaced relation there are provided a series of spacer rods or tie members 7. While the drawing shows two such tie members, it will be understood that a greater number may be employed, depending upon the .size and weight of the respective horn sections 1 and 2. Adapted to surround the flanged portion 6 of the member 4 is a ring 8, preferably metallic, which is provided with an upturned flange 9, corresponding to the flange 6. The flange 9 is of larger internal diameter than the flange 6, so as to allow the constricted end of the horn section 1 to be clamped between the said flanges 6 and 9, as for example by suitable bolts 10 or the like. In order to support the flared ends of the horn sections 1 and 2 there are provided a series of tie members 11 which are bolted at their upper ends to the tie members 7 and are fastened in any convenient manner at their lower ends to the rim of the ring 8. The structure above described thus provides a very simple, and at the same time highly eflicient horn which has throughout the greater part of its length an annular sound chamber, and which has a substantially cylindrical mouth.

It will be understood, of course, that the flared ends of the members 1 and 2 may be given any desired curvature so as to direct the sound at'any desired angle with respect to the axis of the'horn. The structure thus described may form a sound chamber for any well known type of sound generating device. and while the horn is particularly well suited to electro-magnetic sound generators, it will be understood that the invention is not limited thereto. However, when an electro-magnetic translating device is used in conjunction with the horn structure described, this translating device may be attached in any convenient manner to the constricted end of the horn. For example, by fastening it to the ring 8, as will be apparent to those familiar with the art.

However, under certain circumstances it may be desired to increase the effective length of the horn from that shown in the upper part of Fig. 1, in which event instead of attaching the sound translator directly to the ring 8, there may be positioned between the said translator and the ring 8 another sound directing chamber 12 such as a conventional horn, as illustrated in the lower portion of Fig. 1. Preferably the section 12 is designed to conform to the taper of the annular horn above described. The manner of supporting the sound translator devices (not shown) to the lower end of the member 12 is well known in the art, and further description thereof is not believed necessary at this point.

Instead of employing an elongated sound director 12, to couple the sound translator to the annular horn, it will be understoodthat any other known form of sound directing chamber may be employed. For example, there is shown schematically in Fig. 4, the

manner in which the annular horn of Fig. 1 i

may be used in conjunction with a large diaphragm sound translator. In this figure there is shown in a general way a conventional type of large diaphragm unit. For example, a unit of the type usually known as a dynamic speaker. This unit comprises in general a field magnet 13 and a voice coil 14 (which is energized by the currents to be translated into sound), and a conical diaphragm 15 which is preferably supported on the ring 8 by a flexible rim or bond 16. If desired, the impedance of the diaphragm system with respect to the horn system may be matched, as is well known in the acoustic art, although this is not absolutely necessary.

While one specific arrangement and shape of the horn sections 1 and 2 is shown, it will be understood that the invention is not limited thereto, and that various modifications and changes may be made without departing from the spirit and scope of the invention, and furthermore, while one specific arrangement of means for maintaining the sections 1 and 2 in the proper spaced relation is shown, the invention likewise is not limited thereto.

Furthermore, while the drawing shows the sections 1 and 2 in fixed spaced relation, it will be understood that these respective sections may be movable with relation to each other to vary the shape of the sound passage, as may be found desirable.

What is claimed is:

1. A horn structure comprising an outer wall member having a constricted neck at one end and a flared bell at the other, an inner wall member also having a constricted neck and a flared end, the constricted neck of the outer member being open and the constricted neck of the inner member being closed, both said members being substantially co-extensive and means for supporting the said horn members in spaced relation so that the sound emerges therefrom uniformly in a radial direction.

5 2. In a structure of the character described the combination of an outer flared horn member, an inner flared hollow horn member, and means for supporting said members in spaced relation to define an annular sound 1 chamber of progressively increasing cross section, and with a sound exit for directing the sound uniformly in all radial directions from the horn.

3. The combination according to claim 2 in 1 which the outer horn member has its constricted end open to communicate with a sound translator, and the inner horn member has its constricted end closed with its flared end open.

4. In combination an outer tapered horn member having its constricted end open, an inner tapered horn member having its constricted end closed, both said wall members having portions extending substantially at right angles to the axis of the horn and a sound translator communicating with the open constricted end of said outer horn member, said members being positioned one within the other to define a. substantially cylindrical mouth for radiating sound uniformly in all radial directions from the horn.

5. An annular horn comprising an outer tapered horn member, an inner tapered horn member, means for supporting the constricted ends of said members in spaced relation, and means for supporting the enlarged ends of said horn members in spaced relation, the enlarged ends of the horn members having substantially right angled flares whereby the sound is directed uniformly in all radial directions from the horn.

6. In a horn structure of the character described, the combination of a tapered horn and a tapered plug positioned in the enlarged end of the horn, both the horn and plug'having correspondingly flared and enlarged ends whereby sound emerges from said horn substantially uniformly in all radial directions.

7. A horn structure according to claim 6 in which the tapered plug is positioned within the horn with its constricted end facing the constricted end of the horn, and with the flared ends disposed to form a substantially cylindrical mouth.

8. A horn structure according to claim 6 in which the plug is hollow.

9. A horn structure comprising a hollow tapered member, a tapered plug supported within said member, and a separably conical sound chamber supported at the constricted end of said horn member, both the member and plug having correspondingly flared enlarged ends.

10. A structure of the character described comprising a tapered horn having a constricted open neck, a ring supported at said neck, a tapered plug having its constricted end supported by said ring, and means for maintain ing the enlarged ends of the horn and the enlarged ends of the plug in spaced relation.

11. A structure according to claim 10 in which the said ring has attached thereto a sound translating unit.

12. A horn comprising two separable sections one section being provided with a conical sound chamber and the section being provided with an annular sound chamber.

13. A horn structure comprising two separable sections, one section having a conical sound chamber, the other section having an annular sound chamber with a cylindrical sound outlet whereby the sound is emitted uniformly in all radial directions from the horn. means for fastening said two sections together as a unit with their sound chambers extending in the same direction longitudinally of the horn.

14. A horn structure comprising a pair of hollow nested horn members having a constricted end and a flared end, means for supporting the constricted ends of the horn members in spaced relation, and means for supporting the flared ends of the horn in spaced relation, the last mentioned means being adjustable to vary the size of the annular sound chamber of said horn.

ALEXANDER I. ABRAHAMS.