US2918895A - Fluid powered horn - Google Patents

Description

Dec. 29, 1959 R. D. BUELL FLUID POWERED HORN Filed March 14. 1957 .Z'ZVEHZUF For 0. 50541.

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United States Patent FLUID POWERED HORN Roy D. Buell, Chicago, Ill. Application March 14, 1957, Serial No. 645,966 2 Claims. (Cl. 116-142) This invention relates to a fluid powered horn.

The present invention contemplates the utilization of plastics having suitable properties in the construction of a horn. In a preferred embodiment, the invention also contemplates the use of a minimum number of parts, thereby minimizing the assembly labor required. Further, a horn construction is provided which will insure the successful operation of the horn under various operating conditions, and without damage due to environmental factors.

Accordingly, it is an object of this invention to provide a novel horn having excellent tonal qualities.

It is a further object of this invention to provide a fluid powered horn having simplified supporting means for the horn and for furnishing pressurized fluid thereto.

A still further object is the provision of a horn which will withstand the conditions encountered in marine and automotive service.

Yet another object is the provision of a horn which may be manufactured at an extremely low cost by the elimination of nearly all machining.

Many other advantages, features and additional objects of the present invention will become manifest to those versed in the art upon making reference to the details of description in the accompanying sheet of drawings, in which a preferred structural embodiment incorporating the principles of the present invention is shown by Way of illustrative example.

On the drawing:

Fig. l is an elevational view of a horn constructed in accordance with my invention and carried by a supporting surface;

Fig. 2 is an enlarged elevational view, partially broken away, taken along the line II1I of Fig. 1; and

Fig. 3 is a cross-sectional view taken along line IIII1I of Fig. 2.

As shown on the drawing:

Referring to Fig. 1, a fluid powered horn is generally indicated at 10. The horn comprises a housing 11 and a flared body 12 carried by a supporting surface S. A source of pressurized fluid (not shown) is connected to the signal horn at 13. The pressurized fluid may comprise air, carbon dioxide, Freon or any other gas. However, flammable gases should be avoided for safety reasons.

The housing 11 includes a base portion 15, preferably formed of a plastic such as molded nylon, and a cover portion 16, preferably also molded of the same plastic as the base portion 15. The base portion 15 has a wall 16a in which is carried an integral sleeve 17. The inner. end of sleeve 17 provides an annular seat 18 which is inwardly directed from wall 16a into a chamber 19 defined by the base and cover portions 15 and 16. Thus, the seat 18 defines an opening which may be termed an exit opening 20 in one wall 16a of the housing 11.

The body 12 comprises rigid plastic, for example nylon. Its outer end is flared as at 2-2 and it is tubular throughout its length. The rigid plastic body is supported at its opposite end within the sleeve 17 and is secured therein, as by solvent cement. While the outer end 22 is flared as shown in Fig. 1, the other end 27 comprises a straight portion of substantially constant diameter. The pitch of the horn is dependent upon the length of the body 12. Thus, a single mold may be utilized for making a relatively long body. Shorter bodies, otherwise similar, have higher tones or pitches. Thus, prior to assembly with the housing 11, the end 27 of the body 12 may be cut to a desired length. If the original length be cut in half, the frequency of the pitch is doubled and the note is one octave higher than is the note of an unshortened tube. Thus, the broken lines 24 and the dot-dash lines 25 represent various lengths to which the body '12 may be reduced so as to provide a horn having a desired pitch. This is particularly of interest where horns are tonally or musically matched. Thus, so long as the end portion 27 is of uniform diameter, regardless of where it may be cut oil, it will fit into the opening in the sleeve 17 of the housing 11. Thus also the flared body may be said to be the outlet from the chamber 19.

The base portion 15 has a flange 30 which has a surface which is substantially aligned with the seat 18. Carried by the housing against the surface of flange 30 and seat 18 is an imperforate diaphragm 31, here shown to be of metal, for example phosphor bronze. An annular gasket 32, for example of paper, may be provided against the diaphragm 31. The cover portion 16 of the housing 11 has a flange 33 which is substantially coextensive with the flange 36*. Fastening means, here illustrated as being a plurality of bolts 34 and nuts 35, securely clamp the periphery of the diaphragm 31 and the gasket 32 between the flanges of the cover and base portions of the housing.

While one surface of the diaphragm 31 is engaged by the seat 13, the other or opposite surface of the diaphragm is engaged by means which do so at points spanning the seat 18. In Fig. 3, the spanning means is shown as comprising a rigid cup 40, the open end of which forms a continuous circular line which is substantially concentric with the annular seat 18. Thus, the cup 40 or backing means has a diameter which exceeds that of the seat 18. The open ended spanning means 40 comprises metal or rigid plastic and is supported by the cover portion 16 of housing 11, as by a rigid adjustment means 41. Thus, the cup is rigidly, movably and adjustably supported with respect to the housing.

The adjusting means 41 is here illustrated as being a self-tapping screw which not only supports the cup 40 coaxially with the seat, but also permits the selection of the force by which the cup 41 acts against the diaphragm 31. The screw 41 may be thus used to further control the tuning of the horn.

It can be seen that the imperforate diaphragm 31 divides the chamber 19 into two portions, the one portion having the outlet 20, the other portion containing the cup 40. A vent 42 is provided in the cup and vents 43 and 44 are provided in the cover portion 16, thereby venting the side of the diaphragm opposite to that engaging the annular seat 13. Venting of one side of the diaphragm improves the ability of the diaphragm to vibrate against the seat 18. Since water could conceivably condense Within the portion of the chamber carrying the cup 40, it is preferred that one vent, for example 44, be so positioned that any moisture which may be present may drain from that portion of the chamber.

The portion of the chamber 19 surrounding the annular seat is provided with a restricted inlet 45 which is carried within a mounting portion 46 of the base portion 15 of the housing 11. The mounting portion 46 further has a mounting surface 47 which has a configuration conforming to the supporting surface against which the horn is to be mounted. In the drawing, the surface 47 is shown to be flat, thus conforming to a flat supporting surface S. Extending from the mounting surface 47 to the restricted inlet 45, the mounting portion 46 has a cylindrical wall 48 which defines an opening communicating with the restricted opening 45, and extending to the surface 47. Means, generally indicated at 50, are provided 3) for simultaneously securing the horn to the supporting surface S, and for simultaneously providing means for connecting a source of pressurized fluid to the horn. Thus, the means 50 comprises a removable hollow securing means which has a threaded portion 51, for example having self-tapping threads, an external shoulder 42, which may be integral with the means 50, and an external portion 53 which is adapted to be connected to the source of pressurized fluid. When the horn has been placed in position on the supporting surface S, such as over a small hole, the means 50 are inserted from the opposite side through the supporting surface S, and into the opening 48. When the means 50 are drawn up tightly so that the threads 51 form a tight seal with the inner wall 48, and so that the shoulder 52 in cooperation with the surface 47 clamps against the supporting surface S, a pressurized supporting connection has been completed. Thus, the portion 46 comprises an integral mounting portion having a mounting surface which is intersected by a wall defining an inlet opening into which removable securing and fluid supply means may be received.

It is also preferable to provide mounting means at the flared or distal end of the body 12. Accordingly, I have provided a boss 55 as shown in Fig. 1, molded to the outer end of the body 12. The boss 55 bears against the supporting surface S, through which a means projects, for example self-tapping screw 56.

When a pressurized fluid such as air or Freon gas is admitted to the horn via the opening in connection means 13, it flows into the inlet chamber 48, through the restricted passageway 45, and into the annular portion of chamber 19 surrounding seat 18 on one side of the diaphragm 31. In its free position, the diaphragm 31 is in engagement with seat 18. Pressure builds up at the annular portion of the diaphragm surrounding the seat 18, causing the diaphragm 31 to move away from the seat. The air then flows between the diaphragm and the seat, into the opening 20 and out through the body 12. It will be appreciated that the amount which the diaphragm moves before air begins to flow is exceedingly small. As soon as the air has begun to flow, the increase in velocity at the seat causes a reduction of pressure acting on the one side of the diaphragm, whereupon the diaphragm reseats itself. The cycle is continuously repeated so that the motion of the central portion of the diaphragm is oscillatory or vibratory. The oscillating portion of the diaphragm has a certain fixed mass and a certain resiliency, which affect the pitch. The resiliency may be varied by adjusting the force applied to the opposite side of the diaphragm by the cup 40 by screw 41.

Accordingly, I have provided a novel fluid-operated horn construction, in which the use of plastic is particularly advantageous for several reasons. Aside from the fact that it is light, durable, capable of being used under various conditions, resistant to fading and chipping, inexpensive, and moldable, it is particularly useful in that it produces a sonorous tone and yet provides a construction which is readily mountable by very simple means. While various moldable plastics may be utilized in the instant construction, I have found that the use of nylon is particularly advantageous in that it produces good sonority.

Although various minor modifications might be suggested by those versed in the art, it should be understood that E wish to embody within the scope of the patent warranted hereon, all such embodiments as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

1. A signal horn comprising in combination, a housing adapted to be secured to a supporting surface and having a chamber adapted to be connected to a source of pressurized fluid, said housing having an inwardly directed annular seat in one Wall thereof, said seat defining an exit opening from said chamber; said housing having a recess in the wall opposite to said one wall; said opposite wall having a threaded aperture communicating with said recess; a rigid elongated straight tubular plastic sound projector having one end secured in said opening and an opposite flared end extending away from said housing to project sound therefrom; a mounting boss integral with said flared end and extending radially therefrom for being secured to the supporting surface remotely from said housing; a flexible diaphragm supported at its periphery by said housing within said chamber for vibratory movement whereby one side thereof may move out of and into closing relation with said annular seat; an open-ended rigid cup having an axial aperture, said cup being disposed in said recess and having a radial clearance with said recess defining portion of said opposite wall which clearance is smaller than the radius of said axial cup aperture, said cup having a diameter larger than that of said annular seat and engaging the opposite side of said diaphragm with its open end; and an adjustment screw rotatably supported by said housing in said threaded aperture; said screw having a conical tip the largest diameter of which is greater than the diameter of said cup aperture, said tip partially extending into said cup aperture and engaging said cup to space said cup from said housing recess and to supportingly center said cup substantially coaxially with said seat, said cup and screw being effective in cooperation with said projector to adjust the horn.

2. A signal horn comprising in combination, a housing having a chamber adapted to be connected to a source of pressurized fluid, said housing having an inwardly directed annular seat in one Wall thereof, said seat defining an exit opening from said chamber; said housing having a recess in the wall opposite to said one wall; said opposite wall having a threaded aperture communicating with said recess; a sound projector having one end secured in said opening and another end extending away from said housing; a flexible diaphragm supported at its periphery by said housing within said chamber for vibratory movement whereby one side thereof may move out of and into closing relation with said annular seat; an open ended rigid cup having an axial aperture, said cup being disposed in said recess and having a radial clearance with said recess-defining portion of said opposite wall which clearance is smaller than the radius of said axial cup aperture, said cup having a diameter larger than that of said annular seat and engaging the opposite side of said diaphragm with its open end; and an adjustment screw rotatably supported by said housing in said threaded aperture; said screw having a conical tip the largest diameter of which is greater than the diameter of said cup aperture, said tip partially extending into said cup aperture and engaging said cup to space said cup from said housing recess and to supportingly center said cup substantially coaxially with said seat, said cup and screw being effective in cooperation with said projector to adjust the horn.

References Cited in the file of this patent UNITED STATES PATENTS 1,605,854 Putt Nov. 2, 1926 1,655,675 Cunningham Jan. 10, 1928 1,663,648 Cooper Mar. 27, 1928 1,767,740 Buell June 24, 1930 1,915,248 Horton June 20, 1933 2,273,968 Lewis Feb. 24, 1942 2,320,203 Thompson May 25, 1943 2,498,256 Dirnick Feb. 21, 1950 2,579,784 Broden Dec. 25, 1951 2,642,028 Johnson June 16, 1953 2,658,470 Swanson Nov. 10, 1953 2,671,426 Woody Mar. 9, 1954 2,793,651 Gomez May 28, 1957

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