Abstract:
The cabinetry of the present invention facilitates lower manufacturing costs, lighter products that are easier to maneuver and less costly to transport, and simpler product assembly by reducing the number parts to be assembled, while maintaining the structural integrity of the cabinetry. The PTV cabinetry of the present invention utilizes molded plastic foam parts formed from expanded polystyrene or phenolic foam. The foam parts are preferably functionally designed to replace the equivalent parts presently being made by wood fabrication or other molded plastic techniques. In a preferred embodiment, a PTV cabinet may be assembled from thee matching molded foam parts. The foam parts in accordance with the present invention may be uniquely located with respect to one another via locating features molded into the foam parts. Once assembled, an external cabinet or cosmetic fascia part may be placed over the foam parts.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to cabinetry for electronic devices such as projection televisions (PTVs) and, more particularly, to expanded foam cabinetry that facilitates lower manufacturing costs, lighter product weight, lower transportation costs, and simpler product assembly, while maintaining structural integrity.  
         BACKGROUND OF THE INVENTION  
         [0002]    PTVs or “big screen” TVs are a popular alternative to picture tube TVs because they provide comparably larger viewable screens that cannot be efficiently produced using conventional picture tubes. PTV cabinets are presently designed to hold electrical and optical components as required to decipher and project a television picture on a screen generally on the front of the cabinet. The most common PTV on the market today projects pictures created via appropriate electrical and optical components onto a mirror within a box containing the entire apparatus so that the picture reflected to a screen is as large as possible for the volume occupied by the cabinet enclosing it. PTV screens typically range in size from about 45 to about 73 inches along their diagonal, while the cabinets typically range in size from about 48 inches to over 65 inches in height, from about 38 inches to over 65 inches in width, and from about 22 inches to over 29 inches in depth. The cabinets are assembled in an aesthetically appealing manner as required to hold the electrical components, light generator(s), and lenses, mirror and screen in the relationship required to obtain the desired televised picture.  
           [0003]    Most PTVs marketed today include a cabinet constructed from multiple pieces of particleboard cut and glued together. Some cabinets also have plastic components held to the basic cabinet structure with screws or other fasteners. The number of plastic components and particleboard pieces needed to form such cabinets typically range in excess of fifty (50) pieces. As a result, these cabinets tend to be quite complicated and costly to assemble. Because of the size of PTVs, and the particleboard from which the cabinets are typically constructed, PTVs tend to be quite heavy and difficult to maneuver, and, as a result, tend to be costly to transport.  
           [0004]    Alternative methods of manufacture are available that may reduce the overall weight of these cabinets and also the number of components necessary to construct such cabinets. For instance, injection molding could be used to form such cabinets out of plastic. However, because of the complexity of the mold needed to accommodate the high operating pressures (typically 300-500 psi) that the mold is subjected to during the injection process, injection molding these cabinets tends to be costly and time consuming. The injection mold for such cabinets is likely to cost in the range of about one million to one and one-half million dollars and likely to take up to twenty (20) weeks or more to design and manufacture. Because of the high costs and long lead times, injection molding is a less than desirable alternative to conventional methods.  
           [0005]    Another alternative would be to vacuum form the cabinetry out of plastic. Although attractive from a tooling cost standpoint, vacuum forming has its drawbacks. Vacuum forming tends to result in inconsistent material cross-sections, high material waste and high labor costs.  
           [0006]    Thus, it would be desirable to provide cabinetry for electronic devices such as PTVs, and for other storage applications, that is easy to manufacture, that reduces the weight of end products, that reduces manufacturing and transportation costs, and that is resilient and structurally sound for the particular application.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention is directed to cabinetry for a variety of storage applications and, more particularly to cabinetry for electronic devices such as PTVs that, when compared to conventional cabinetry, tends to be simpler to manufacture, lighter in weight, less costly to manufacture and transport, and easier to handle. Although significantly lighter in weight, the structural integrity of the cabinetry of the present invention tends to be comparable to conventional cabinetry. In a particularly innovative aspect, the cabinetry of the present invention utilizes molded plastic foam formed from expanded polystyrene or phenolic foam that is sandwiched between coatings of an appropriate structural material such as plastic to form the desired cabinet or cabinet component. Preferably, a coating of urethane may be sprayed onto the surface of the foam parts to provide a resilient and cosmetically appealing surface finish to the foam parts. The foam parts are preferably functionally designed to replace the equivalent parts presently being made by wood fabrication or other molded plastic techniques.  
           [0008]    In a preferred embodiment, a PTV cabinet of the present invention may be assembled from three matching cabinet components formed from the preferred sandwich structure comprising expanded polystyrene and structural coatings. The foam parts are preferably fastened to a generally flat base formed from wood, particleboard, concrete or some other appropriate material. An external cabinet or cosmetic fascia part formed from injection molded or extruded plastic, or particle board, may be placed over the foam parts and fastened to the base to hold the assembly together.  
           [0009]    In another innovative aspect, the foam parts in accordance with the present invention may be uniquely located with respect to one another via locating features molded into the foam parts.  
           [0010]    In another innovative aspect, the foam parts in accordance with the present invention include mirror-capturing members adapted to capture the mirror of the PTV upon assembly of the foam parts.  
           [0011]    In yet another innovative aspect, a PTV cabinet in accordance with the present invention may be formed as a unitary member from the preferred sandwich structure comprising expanded polystyrene and fastened to a base assembly comprising a base platform and a speaker panel fastened thereto.  
           [0012]    Other innovative aspects of the invention include the preceding aspects individually or in combination.  
           [0013]    Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is an isometric exploded assembly view of a PTV cabinet in accordance with the present invention.  
         [0015]    [0015]FIG. 2 is an isometric exploded assembly view of the PTV cabinet shown in FIG. 1 wherein the mating top halves of the cabinet are shown assembled.  
         [0016]    [0016]FIG. 3 is an isometric exploded assembly view including of an assembled PTV cabinet, a base, and an external cabinet.  
         [0017]    [0017]FIG. 4 a  is an isometric view of an alternative embodiment of a PTV cabinet in accordance with the present invention.  
         [0018]    [0018]FIG. 4 b  is a plan view of a base assembly for the PTV shown in FIG. 4 a.   
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]    The cabinetry of the present invention tends to facilitate lower manufacturing costs, lighter products that are easier to handle and less costly to transport, and simpler product assembly by reducing the number parts to be assembled. A PTV cabinet in accordance with the present invention preferably replaces most, if not all, of the wooden components found in a conventional cabinet with lightweight molded plastic foam components. The plastic foam components are preferably formed from expanded polystyrene or phenolic that is that is sandwiched between coatings of an appropriate structural material such as plastic. Preferably, a coating of urethane may be sprayed onto the surface of the foam parts to provide a resilient and cosmetically appealing surface finish to the foam parts. The expanded polystyrene foam preferably has a density in a range of about three (3) to six (6) pounds per cubic inch.  
         [0020]    Because expanded polystyrene is so light in weight, strength and durability tend not to be qualities that have been associated with it. As a result, expanded polystyrene has tended not to be considered a viable material for the construction of such things as cabinetry for PTVs, where structural strength and durability are essential qualities of the structure. However, the structural integrity of the cabinetry of the present invention, which is formed from a sandwich structure comprising expanded polystyrene foam sandwiched between plastic surface coatings, has been found to be comparable to that of conventional cabinetry.  
         [0021]    In forming the cabinetry, a mold of the desired cabinet or cabinet component is preferably cast from aluminum or other appropriate material. Prior to injecting the polystyrene into the mold at relatively low pressures in the range of about five (5) to fifteen (15) psi and preferably about eight (8) psi, the polystyrene is subjected to a process known by those skilled in the art to inject a blowing agent, such as heptane, into the polystyrene beads. The polystyrene is then injected into the mold and heated to expand the blowing agent within the beads, which in turn expands the beads such that the polystyrene material coalesces into a generally homogeneous structure as it is pressed against the walls of the mold. Preferably, the polystyrene material is injected into the mold with live steam. The steam tends to drive most of the blowing agent out of the beads, which tends to make the end product more flame retardant. In a preferred embodiment, the polystyrene beads are expanded about twenty (20) times their original size and optionally within a range of about fifteen (15) to thirty (30) times their originally size. Once released from the mold, the cabinet or cabinet component, e.g., a structural panel, is preferably coated with an appropriate structural material such as plastic. In a preferred embodiment, a urethane material, such as Styrothane™, may be used to provide the cabinet or component with a resilient and cosmetically appealing surface finish.  
         [0022]    Referring to FIG. 1, the PTV cabinet  10  in accordance with the present invention is preferably formed in a manner described above from a sandwich structure comprising expanded polystyrene foam sandwiched between plastic coatings. As shown, the PTV cabinet  10  preferably includes a base cabinet  12  for housing an optical unit of the PTV and a top cabinet portion  20  for housing a mirror and hanging a screen of the PTV. As discussed below, the top cabinet  20  is mountable on the base cabinet  12 . The top portion  20  may comprise two mirror image mating halves  21   a  and  21   b  or a unitary component similar in appearance to the assembled top cabinet  20  shown in FIG. 2. The left and right top halves  21   a  and  21   b , respectively, include integrally formed top panels  22   a  and  22   b , side panels  23  and  24 , and rear panels  25   a  and  25   b . The rear panels  25   a  and  25   b  include top  28   a  and  28   b , bottom  26   a  and  26   b , and middle  27   a  and  27   b  portions. The two halves  21   a  and  21   b  also include internal mating surfaces  30   a  and  30   b , which preferably have matching outer contours. Locating features are preferably molded into the two halves  21   a  and  21   b  so that the two halves  21   a  and  21   b  may be uniquely brought together to make a closed top assembly  20  for the cabinet  10 . The locating features may include pins or tongue and groove features molded into the mating halves  21   a  and  21   b . As shown in FIG. 1, a series of locating holes  29  are molded into the left top half  21   a  extending into the left half  21   a  from the left internal mating surface  30   a . The locating holes  29  are sized and positioned to receive locating pins (not shown) integrally formed with the right top half  21   b  and extending from the right internal surface  30   b  of the right top half  21   b.    
         [0023]    In bringing the two halves  21   a  and  21   b  together, the PTV mirror (not shown), which is required to direct the projected image within the cabinet  10  on to a screen (not shown), may be captured between the top cabinet halves  21   a  and  21   b . This advantageously minimizes the steps needed to assemble the PTV. In a preferred embodiment, grooves  33  may be formed in the side panels  23  and  24  adjacent to the rear panels  25   a  and  25   b  of the left and right halves  21   a  and  21   b . The grooves  33  are preferably sized and configured to capture a mirror when the top cabinet halves  21   a  and  21   b  are brought together. The mirror may also rest on recesses  32   a  and  32   b  formed in the top of the middle portions  27   a  and  27   b  of the rear panels  25   a  and  25   b.    
         [0024]    Once assembled, the top part  20  of the cabinet  10  may appear as one piece as show in FIG. 2. The bottom cabinet  12  preferably includes a box-like body  13  having front  14  and rear  15  cutouts to reduce the weight of the bottom cabinet  12 . The front cutout  14  may accommodate audio speakers and a speaker panel (not shown). The bottom cabinet  12  includes an internal top mating surface  16  that preferably matches an internal bottom mating surface  34  of the-top cabinet  20 . The top cabinet  20  and bottom cabinet  12  preferably include unique locating features such as locating pins or tongue and groove locators molded into their abutting surfaces to uniquely locate one with respect to the other. As shown in FIGS. 1 and 2, pin locating holes  17  are formed in the bottom cabinet  12 . The locating holes  17  extend into the bottom cabinet  12  from the top mating surface  16  and are preferably sized and positioned to receive locating pins (not shown) integrally formed with the top cabinet  20  and extending from the bottom mating surface  34  of the top cabinet  20 .  
         [0025]    With the top and bottom cabinets  20  and  12  assembled together, the bottom or base cabinet  12  is fastened to a general flat base  40 , as shown in FIG. 3. The base  40  is preferably formed from wood, particleboard, concrete or some other appropriate material. Where necessary, the weight of the base may be increased to tend to reduce the tip potential of the assembled package.  
         [0026]    As shown in FIG. 3, an external cabinet or cosmetic fascia  50 , which is generally U-shaped, is preferably placed over the foam portions  20  and  12  of the cabinet structure  10  toward the front of the cabinet  10 . The entire assembly  10  is preferably held together by fastening the external cabinet  50  to the base  40 . The external cabinet or cosmetic fascia  50  is preferably formed from injection molded or extruded plastic.  
         [0027]    The foam parts  12  and  20  of the cabinet  10  are preferably coated with a structural material to form the desired sandwich structure. A urethane material, such as Styrotane™, may be used to provide the cabinet  10  with a resilient and cosmetically appealing surface inside and outside. Alternatively, the exterior of the PTV cabinet  10  may be coated with a material that is less costly due to its flamability rating. With such a surface finish, the cabinet  10  may optionally be assembled without the external cabinet  50  by fastening the top cabinet  20  to the bottom cabinet  12 , and then fastening the bottom cabinet  12  to the base  40 . In such instances, plastic fastener anchors may be used to properly anchor the fasteners in the foam part.  
         [0028]    Turning to FIGS. 4 a  and  4   b , an alternative embodiment of the present invention is shown to include a PTV cabinet  100  of unitary design formed in a manner described above from a sandwich structure including expanded polystyrene foam sandwiched between a structural material such as plastic. The unitary cabinet  100  includes an upper enclosure portion  110  for housing a mirror and hanging a screen, and a lower enclosure portion  120  for housing an optical unit. The cabinet  100  is partitioned into the upper and lower enclosures  110  and  120  by partition members  125   a  and  125   b , which extend inwardly from side panels  123  and  124 . The bottom of the cabinet  100  is preferably fastened to a base assembly  130  comprising a speaker panel  132  formed from wood, particle board, or some other appropriate material, fastened to a base platform  134  formed from wood, particle board, concrete, or some other appropriate material. Recesses  127  and  128  may be formed in the side panels  123  and  124  and partition members  125   a  and  125   b  to accommodate the speaker panel  132 . Where necessary, the weight of the base platform  134  may be increased to reduce the tip potential of the assembled package.  
         [0029]    For exemplary purposes only, the foregoing discussion of the present invention focused on cabinetry for PTVs. However, one skilled in the art would understand that a cabinet made in accordance with the present invention could be used to house a variety of electronic components or used in a variety of storage applications. Alternatively, sandwich structured panels formed in a manner described above may be used to form a variety of enclosures.  
         [0030]    While the invention is susceptible to various modifications and alternative forms, a specific example thereof has been shown in the drawings and is herein described in detail. It should be understood, however, that the invention is not to be limited to the particular form disclosed, but to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims.