Abstract:
A light weight fully assembled speaker enclosure is provided that includes a backbox having a peripheral edge; a grill that is crimped around the peripheral edge of the backbox, and a sound-baffle sheet disposed between the backbox and the grill, the sound-baffle sheet having an opening for placement of a speaker. Also provided is a speaker system having an audio speaker; a backbox having a peripheral edge; a grill that is crimped around the peripheral edge of the backbox and that is affixed to the speaker; and a sound-baffle sheet disposed between the backbox and the grill, the sound-baffle sheet having an opening for placement of the speaker.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. §119(e) to co-pending provisional patent application Ser. No. 60/211,574, filed Jun. 15, 2000, the entirety of which is incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to speakers for placement in ceilings, walls, and the like. The present invention is specifically directed to a low profile, lightweight, fully assembled lay-in speaker system which replaces a standard ceiling tile. 
     BACKGROUND OF THE INVENTION 
     Conventional speakers oftentimes require holes to be cut in a ceiling tile so that the speakers can be placed in the holes. Cutting ceiling tiles is messy, costly, and time-consuming. It also decreases the structural integrity of the ceiling tile. Conventional speakers also require substantial expense of time and labor for the installation, and cost in terms of hardware required for mounting. 
     Access to conventionally mounted speakers is also problematic. Particularly in large buildings, such as theaters or offices, access to conventionally mounted speakers for cleaning, maintenance, and adjustment is cumbersome and labor intensive. Additionally, individual speaker volume control is not readily accessible for conventionally mounted speakers. 
     Furthermore, conventional speakers are heavy, thereby requiring additional support, such as wire hangers, to connect the speaker to the ceiling. See, for example, U.S. Pat. No. 4,923,032 to Nuernberger. 
     In addition, conventional speaker do not provide a minimum three-hour burn rating. While building codes require burn-resistant materials to be used in ceiling tiles themselves, building and fire codes do not require burn-resistant materials to be used in speakers, creating a potential fire hazard. Conventional backboxes are made of a metal, such as steel, which do not provide a three-hour burn rating. Thus, a fire hazard exists wherever a conventional speaker is located. 
     SUMMARY OF THE INVENTION 
     The present invention, which is defined by the claims set out at the end of this disclosure, is intended to solve at least some of the problems noted above. A speaker enclosure is provided that includes a backbox having a peripheral edge; a grill that is crimped around the peripheral edge of the backbox, and a sound-baffle sheet disposed between the backbox and the grill. An opening is placed in the sound-baffle sheet for placement of a speaker. 
     Also provided is a speaker system having a speaker, a backbox having a peripheral edge, a grill that is crimped around the peripheral edge of the backbox and to which is affixed a speaker, and a sound-baffle sheet disposed between the backbox and the grill. The crimping of the grill serves several other purposes. It makes a nearly airtight seal with the grill and sound-baffle sheet, which minimizes possible smoke seepage between the room and the ceiling. Further, it prevents sound waves from the front of the speaker from entering the enclosure and canceling at various frequency points. The sound-baffle sheet has an opening in it to accommodate the speaker. 
     Crimping the grill over the backbox increases the strength of the backbox, thereby providing structural integrity both to the grill and backbox. In addition, the backbox preferably is made of a material that has good high temperature insulation properties to achieve a three-hour burn rating. 
     The speaker system of the present invention offers a number of other advantages over speakers known to the prior art. Because of its size and dimensions, there is no need to cut ceiling tiles to accommodate the speaker, which eliminates the mess and difficulty normally present with installing speaker systems in ceilings. The lay-in speaker system also provides easy access for maintenance and repair by providing access through adjacent ceiling tiles. The speaker system also provides an inconspicuous front accessible volume control for the speaker. In addition, the integral backbox meets or exceeds ASTM E84 flame and smoke test with 3 hour burn. 
     Further advantages, features, and objects of the invention are apparent from the following detailed description of the invention in conjunction with the associated drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a preferred embodiment of a speaker enclosure made in accordance with the invention. 
         FIG. 2A  is a top plan view of a preferred embodiment of a grill made in accordance with the invention. 
         FIG. 2B  is a perspective view of the grill of FIG.  2 A. 
         FIG. 2C  is a side plan view of the grill of FIG.  2 A. 
         FIG. 3A  is a top plan view of a preferred embodiment of a sound-baffle sheet without the speaker opening, made in accordance with the invention. 
         FIG. 3B  is a top plan view of the sound-baffle sheet of  FIG. 3A , which includes a speaker opening. 
         FIG. 4  is a perspective view illustrating the ventral side of the speaker system, which includes the grill, sound-baffle sheet, and speaker made in accordance with the invention. 
         FIG. 5  is a cross-sectional view of the speaker system illustrated at lines  5 — 5  in FIG.  1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, a first preferred embodiment of the speaker enclosure system in accordance with the present invention is illustrated in  FIG. 1  at the reference numeral  10 . The speaker enclosure system  10  is a ceiling speaker preferably having the same size as a standard ceiling tile. As such, the speaker enclosure system  10  is designed to replace an entire ceiling tile and to rest on the same tile framework support. Thus, the speaker enclosure system  10  does not require any additional framework or support for placement on ceiling other than the framework already installed for the tile. The speaker enclosure system  10  therefore blends in with the rest of the ceiling tiles and does not obstruct access to, or the view of, the ceiling. 
     Unlike conventional ceiling speakers, there is no need to cut a ceiling tile. A standard 2 foot by 2 foot size is useful for the speaker enclosure  10 , although the speaker enclosure system  10  can be made of virtually any size to match the size of the existing ceiling tiles. 
     In a preferred embodiment shown in  FIG. 1 , the speaker enclosure system  10  has a backbox  20 , which encloses the speaker in order to comply with building codes. The backbox  20  includes a peripheral edge  22 , walls  24  and an upper surface  26 . As illustrated, the walls  24  are angled and slightly curved. It is within the scope of the present invention to provide walls of other shapes if desired. The walls  24  meet at edges  28 , which are slightly curved as illustrated. Backboxes having other shapes and sizes are well within the scope of this invention. The upper surface  26  of the backbox  20  includes an electrical connection box  25 , known to the art for supplying electricity to the speaker. 
     Preferably, the backbox  20  is a concave, molded, one-piece form having the top surface  26 , sides  24  and an edge  22 . More preferred is a concave, molded, one-piece fiberglass, mineral fiber, or other suitable fiber-covered material, form enclosed on one side by a foil or other suitable metallic coating. The fiberglass and foil combination provides a light-weight construction. 
     The backbox  20  also preferably is made of a material that is flame resistant. More preferably, it has a three-hour burn rating. The fiberglass and foil combination provides such a three-hour burn rating. The material preferably passes an American Society for Testing and Materials (ASTM) E84 flame and smoke test, which is a standard test method for surface burning characteristics of building materials. The method assesses the spread of flame on the surface of a material and is often referred to as the “Tunnel Test.” The test involves installing a sample of material 20 inches wide and 25 feet long as the ceiling of a horizontal test chamber. The material is exposed to a gas flame on one end of the tunnel for a period of 10 minutes. The rate of flame front progression on the material is compared to selected standards and calculations made to produce a flame spread rating. The fiberglass and foil combination pass the ASTM E84 test. Also useful is a backbox  20  material that passes a Underwriters Laboratories (UL) 181 erosion and impact test. This test measures the fire resistance and surface burning characteristics of materials and fabrics, as well as ventilation characteristics of products installed in air ducts. The Standard evaluates a risk of fire, electric shock, or injury to persons, using the appropriate additional component and end-product requirements as necessary to maintain the level of safety for the user of the product as originally anticipated by the intent of this Standard. The test is designed for any product that contains features, characteristics, components, materials, or systems that are installed in air ducts. Products are classified based on their combustibility. 
     Illustrated in  FIGS. 2A-C , the speaker enclosure system  10  also includes a grill  30  that is crimped at edges  34 , as illustrated in FIG.  1 . The edges  34  are designed to crimp around the peripheral edge  22  of the backbox  20 . The backbox  20  can also be attached to the grill  30  by other means such as adhesive, mechanical fasteners or an overlying piece to press the backbox  20  against the grill  30 . 
     A preferred grill  30  is illustrated in  FIGS. 2A-C . The grill  30  preferably is a perforated sheet designed to allow sound from a speaker  50  (illustrated in  FIG. 4 ) to pass through it. Preferably, the perforations  31  are large enough to allow a screwdriver or similar device to be inserted through them. This permits adjustment of a volume control (not shown) on the speaker  50 , which is shown later in FIG.  4 . Conventional grills typically have smaller perforations through which do not accommodate a screwdriver or other similar tuning device. Thus, to adjust the volume on a speaker having a conventional grill, a hole must be drilled to enlarge the perforation or a speaker adjustment knob must be placed on the exterior surface of the grill. 
     Referring to  FIG. 3A , a sound-baffle sheet  40 , preferably made of vinyl or thin MYLAR, is disposed between the grill  30  and the backbox  20 . Preferably, the sound-baffle sheet  40  is constructed of two pieces  40   a  and  40   b  that are placed side-by-side as is shown in FIG.  4 . However, the sound-baffle sheet  40  can be constructed of a single piece. A series of openings  42  are cut in the sound-baffle sheet  40   b  as is shown in FIG.  3 B. Typically, the size of the opening  42  approximates the diameter of the speaker  50 . A second opening  43  of appropriate dimension may be added to the sound baffle sheet away from the speaker to introduce tuning of the enclosure to improve the low frequency response of the unit. 
     The speaker  50  is placed over the opening  42  of the sound-baffle sheet  40   b  as is illustrated in FIG.  4 . The speaker  50  is then attached to the grill  30 . Preferably, the attachment is permanent, such as by rivets, nuts and bolts or other attachment devices  51  attaching the speaker  50  to the grill  30  through the perforations in the grill  30 . 
     Referring to  FIG. 4 , the sound-baffle sheet  40  forms an effective acoustical baffle. Sound waves emitted from the baffle  54  of the speaker  50  exit through the perforations of grill  30 . Because sound waves can return to the speaker enclosure system  10  through the perforations  31 , which tends to distort or dampen sound and is not desired, the sound-baffle sheet  40  acts to prevent sound waves from reentering the speaker  50 . Thus, the sound moves into a room and is not dampened or canceled. The speaker  50  may be any speaker known to the art. 
     Illustrated in  FIG. 5 , the grill  30  is secured to the backbox  20  by crimping the edges  34  of the grill  30  around the peripheral edge  22  of the backbox  20 .  FIG. 5  shows the backbox  20  and the grill  30  before the grill edges  34  are bent over the peripheral edge of the backbox  20 . The crimping strengthens the backbox  20  and grill  30  combination, thereby providing additional structural integrity to the combination. The crimping also provides an economical method of speaker construction by eliminating the need for additional hardware to hold the speaker enclosure together. The elimination of additional hardware also reduces the cost of the speaker enclosure as a whole. In addition, crimping provides an easy and reversible means to disengage the backbox  20  from the grill  30  if it is necessary to separate the two. 
     The speaker enclosure  10  can also be manufactured with a sound masking generator built into the system. The appearance of the grill  30  is appropriate for the sound of the sound masking generator, i.e, it sounds like air coming from a ventilation grill. The unit has an appearance similar to a ventilation grill. 
     It is understood that the various preferred embodiments are shown and described above to illustrate different possible features of the invention and the varying ways in which these features may be combined. Apart from combining the different features of the above embodiments in varying ways, other modifications are also considered to be within the scope of the invention. 
     For example, the speaker enclosure  10  can be used in a ceiling or a wall. The speaker enclosure  10  can be placed where two adjacent walls meet, preferably near the ceiling. 
     The invention is not intended to be limited to the preferred embodiments described above, but rather is intended to be limited only by the claims set out below. Thus, the invention encompasses all alternate embodiments that fall literally or equivalently within the scope of these claims. It is understood that in the claims, means plus function clauses are intended to encompass the structures described above as performing their recited function, and also both structural equivalents and equivalent structures. As an example, though a nail and a screw may not be structural equivalents insofar as a nail employs a cylindrical surface to secure parts together whereas a screw employs a helical surface, in the context of fastening parts, a nail and a screw are equivalent structures.