US2746559A - Serving tray mounted loud-speakers - Google Patents

Description

May 22, 1956 l. w. MASTIN 2,7 6,

SERVING TRAY MOUNTED LOUD-SPEAKERS Filed June 1, 1954 INVENTOR. /l/A/\/ n/ MAST/N BY w wzm A TTOQ/VE V5 SERVING TRAY MOUNTED LOUD-SPEAKERS Ivan W. Mastin, Bellingham, Wash.

Application June 1, 1954, Serial No. 433,485

3 Claims; (Cl. ISL-31) The present invention relates to mountingsfor loudspeakers such as used for radio receiving sets, communication systems, and the like, and is directed particularly to the mounting of such a loud-speaker unit on a serving tray.

An object of the present invention is to provide a combination of a loud-speaker and a serving tray which will afiord effective operation of the loud-speaker, although the loud-speaker is mounted unobtrusively. More specifically, it is an object to improve the volume and tonal qualities of a small loud-speaker by associating it with a serving tray, without in the least impairing the value of'the serving tray for its normal use.

It is also an object to mount a loud-speaker on a serving tray in a position such that the appearance of the tray is not impaired, yet it will be convenient to connect the loud-speaker to a radio receiving set, or to a communication system, and a further object in such an assembly is to enable the operation of the loud-speaker to be controlled readily.

Additional objects of the loud-speaker and serving tray combination of the present invention will be pointed out in the following detailed description of such a combination shown in the drawing.

. In general, the combination may include a small loudspeaker incorporating a cone within a housing, having a flange projecting outwardly generally coplanar with the cone. serving tray to locate the cone opening close to such serving tray'bottom. Leg bars may be secured to opposite ends of the tray, and a jack and switch electrically connected to each other and to the loud-speaker may be mounted in one of these leg bars.

The drawing is a bottom perspective view of a serving tray on which a loud-speaker is mounted, parts of the tray and loudspeaker housing being broken away to reveal structural details of the combination.

So-called drive-in restaurants are prevalent in many areas of the United States and since the present invention is particularly suited for use in such establishments, theinvention will be described with reference to the requirements of such use, although it will be understood that similar combinations of loud-speakers and serving trays may be used in cafeterias or restaurants of other types. In many restaurants individual loud-speakers are provided at each table to supply music for the enjoyment of the customers. The availability of such music is particularly attractive to young people. Drive-in restaurants also have been most popular with young people, but it has not been possible to provide music for individual automobile customers at a drive-in restaurant heretofore.

Drive-in restaurants have achieved their popularity because of the ability of automobile occupants to be served without getting out of the automobile. The automobile occupants have greater privacy than in the usual restaurant and less effort is involved in eating in ones automobile than in getting out of the automobile and going into the This flange may be secured to the bottom of a 2,746,559 Patented May 22, 1956 its restaurant. The convenience of serving patrons in drivein restaurants has been greatly improved by providing serving trays on which food can be carried and which can be attached to the automobile within easy reach of an occupant. A serving tray type which has proven popular for this kind of service is shown in the drawing as a representative style of tray for incorporation in the present invention.

The conventional type of serving tray mentioned above includes the tray proper having the imperforate bottom 1 with sides 2 extending upward from the bottom around its margin. Across opposite ends of the tray extend leg bars including an upper flat strip 3 having its opposite ends riveted to the tray and a lower strip 4 secured in faceto-face relationship to the strip 3 over most of its length, but having its end portions first offset and then bent at an angle to its main portion to form leg elements 5 projecting away from the tray. Such leg elements may be covered with tubular rubber strips 6. I

Across the central portion of the tray parallel to-tne leg bars 3, 4 is secured a strap 7 the central portion of which is spaced from the tray bottom. The opposite ends of this strap may be riveted to opposite side flanges of the tray, as shown, or to the tray bottom. A brace 8 has one end adjustably connected to the strap 7, and its other end provided with an anti-skid foot 9, such as being formed of rubber material. The end of this brace connected to the strap 7 may have a notch in formed between two lugs 11, which fit over the strap, and such lugs are connected by a rod 12 extending across the face of the strap remote from the brace proper. Such connection enables the strap-engaged end of the brace to be shifted along the strap 7 into any position desired.

Such a serving tray may be attached to the side of an automobile by engaging the legs 6 over the upper edge of a window when slid down almost to the bottom of the window opening. The upper end of the brace 3' may then be moved along the strap '7 to a position corresponding to the angle at which it is desired to set the brace, and the foot 9 is then engaged with the side of the automobile beneath the window opening to support the side of the tray opposite the legs engaged with the automobile window; When the tray is not in use'the end of brace 8 engaging strap 7 may he slid along the strap and the brace swung upward over the strap until lugs 13 on opposite sides of the brace near the foot 9 pass through opposite notches in in the strap, and as the brace is slid further along the strap these lugs will hold the brace in retracted position closely underlying the strap 7.

A loud-speaker ItS may be combined readily and advantageously with an automobile serving tray, of which that described above is anexample. The loud-speaker includes the cone 1' 5 and preferably is substantially en closed within the housing 17. This housing has a flange 18 which is substantially coplanar with the Opel-ling or" the cone 16. The flange is secured to the impcrforate tray bottom 1 with the cone opening adiacen't to such bottom. This attachment may be eflected by bolts 19 extending through the respective corners of the flange 13 and the tray bottom, and, if desired, a gasket 26 of felt or rubber strip material may be interposed between the loud-speaker housing and the tray bottom.

The combination of such a loud-speaker and serving tray in this fashion has many advantages. It is important that the combination of a loud-speaker with a tray not impair the utility of the tray for its intended purpose of serving the occupants of an automobile. Also, the loud-speaker should be mounted so that it cannot be damaged readily and is not unsightly. If a loud-speaker were simply placed on the tray, it could easily be knocked off, and, to the extent of the space which it occupied,

the bottom of the tray, the entire upper surface of the tray can be used in customary fashion. Also, there is little danger of the loud-speaker being struck and injured by dishes, as it might be if mounted on the upper surface of the tray oron the tray edge. Furthermore, the imperforate upper surface of the tray can be washed thoroughly to keep it clean without danger of injuring the loud-speaker when mounted on the tray bottom as described.

While the advantages of mounting the loud-speaker on flte tray bottom pointed out above are important, the most important advantage is in the enhancedutility of the loud-speaker itself. It is customary when the trays are not in use to stack them one upon another. Also, when such a tray is loaded with food it is quite heavy. Consequently, in order to be able to mount a loudspeaker on the tray bottom as described it must be compact and light. At the same time, such a loud-speaker is of little utility if it is. not sufiiciently powerful to enable the occupants of the automobile on the outside of which the tray is mounted to hear music or a message broadcast by the loud-speaker. It is important, therefore, that the operation of the small and light loudspeaker be made as eifective as possible.

Some directional qualities may be given to sounds emanating from the loud-speaker by providing a grill 21 in the side of the housing adjacent to the edge of the tray next to the automobile window. By far the greatest effectiveness in the propagation of sound from the loudspeaker is attained, however, by securing the loud-speaker in a position with its sound wave propagating side, in the instance shown the concave side of the cone, adjacent to and preferably engaging a principal surface of the imperforate tray. This disposition of the loud-speaker converts the entire tray into a sound propagating diaphragm energized by the vibrations of the loud-speaker cone 16. Both the tone and volume of music produced by the loud-speaker are greatly improved by this diaphragm reproduction action of the tray itself.

Since thehousing 17 does not contribute appreciably to the production of the sound because it is small relative to the size of the tray as a whole, it may be made as a one-piece plastic part, and while the tray also may be made of plastic, it is preferred that it be of metal such as of aluminum alloy material. It has been found that the sound-producing efliciency of the tray as a diaphragm is not appreciably impaired by dishes on the upper surface of the tray, although frequently paper plates and cups are used for drive-in restaurant service.

It is, of course, not practical to support a complete radio receiving set on a tray, so that whether the loudspeaker is to reproduce music from such a radio receiving set, from a phonograph, or is to be used to convey a message as in an intercommunicating system, it is necessary to provide for an electrical connection to the loudspeaker at the location of the automobile. Such connection is afforded by mounting on one of the leg bars 4 v between the strips 3 and 4 a jack 22 into which a plug 23 can be inserted. This jack is preferably mounted at the end of a leg bar remote from the end to be engaged with the automobile window. For this purpose it is merely necessary to extend the end of strip 3 and to bend such strip end downward to form a recess as shown, in which the jack 22 is received. The electric wire 24 carrying the plug 23 may be mounted in any suitable manner at the car-parking station and connected to the circuit of a radio receiving set, a phonograph or an inter-.

communicating system.

In use, an attendant in filling the order for patrons in an automobile would mount the tray on the sideof the automobile by use of the hooked legs and brace in the usual manner. .The attendant would then insert the plug 23 into the jack 22. Because this plug and jack is at the side of the tray remote from the automobile,

it is not convenient for an occupant of the automobile I to reach it. Consequently, it is preferred that aswitch switch 25 is received. The switch, jack .22, and loudspeaker may then be suitably interconnected by wires 26, enabling the loud-speaker to be energized or deenergized at will by manipulation of the switch and without the necessity of removing the plug 23 from the 'jack 22; I claim as my invention: i p 1. In combination, a serving tray, a loud,-speaker;including a cone, and means securing said loud-speakervto the bottom of said tray for vibrating said tray to disseminate sound, the upper surface of said tray being unbroken and unobstructed, having unimpaired utility for use as a serving tray. 2. In combination, a serving tray, a loud-speaker in-. cluding a cone, and means carrying said loud-speaker beneath said tray with the vconcave side of said cone facing, adjacent to and closed by the lower surface of said tray for vibrating said tray to disseminate sound, the upper surface of said tray being unbroken and imobstructed, having unimpaired utility for use as a serving tray.

3. In combination, a serving tray, a loudespeaker in- 1 References Cited in the file of this patent i p UNITED STATES PATENTS,

1,882,401 Pierce Oct. 11, 1932 1,893,893 Hammond Ian. 10, 1933 1,899,929 Andrews Mar. 7, 1933 2,160,112 Van Urk et al May 30,1939 2,341,275

Holland Feb. 8, 1944

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