Abstract:
A swivel device intended for electronic equipment and having an upper platform that rotates upon a stationary base. The platform is elevated above the base by means of supports, creating a low profile wiring cavity with a cable supporting bottom surface. The cables from the electronic equipment are passed through the cavity in a manner that controls and protects them. In addition, a post located within the wiring cavity controls the cable path so that the cables are not pulled, entangled, or disconnected during rotation of the platform.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/066,130, filed Nov. 19, 1997. 
    
    
     BACKGROUND—FIELD OF THE INVENTION 
     This invention relates to swivel devices, specifically, swivel devices used to support electronic components and the like having wires, cables or tubes connected to them. 
     BACKGROUND OF THE INVENTION 
     In many devices, such as television sets and computer equipment, it is desirable to have easy access to the back of the device to repair it or to connect electric cables. To provide access, it is known to mount such devices on a rotating platform such as a lazy susan so that the device can be turned at least 180 degrees from its operating position. However, rotating such devices, especially those having many cables connected, can cause the cables to be pulled, entangled, or disconnected from the device. It is desirable, and it is the object of this invention, to provide a rotating platform that can be turned at least 180 degrees without pulling or entangling the cables, to expose the back of the device and thereby provide access to cables and cable connections. 
     BRIEF SUMMARY OF THE INVENTION 
     This invention is a swivel device intended for electronic equipment and having an upper platform that rotates upon a stationary base. The platform is elevated above the base by means of supports, creating a wiring cavity that is low profile and of a shape similar to a low-profile parallelepiped. 
     The cables from the electronic equipment are routed through the cavity in a manner that controls and protects them. The invention can be made substantially open on the sides, allowing the user to easily view, install, and replace the cables. A stop prohibits the platform from rotating more than 360 degreees with respect to the base. 
     The cables must be at least as long as the depth of the platform, as measured from front to back. A post located within the wiring cavity controls the cable path so that the cable service length, being the cable length from the cavity entrance point to the cavity exit point, is substantially constant during rotation of the platform. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Example embodiments are described in the detailed description and shown in the drawings as follows: 
     FIG. 1 is an orthogonal view showing the prior art. 
     FIG. 2 is is an orthogonal view of the preferred embodiment resting in the zero position. 
     FIG. 3 is an exploded view showing the preferred embodiment in the zero position. 
     FIG. 4 is an exploded view showing the preferred embodiment in the 180 position. 
     FIG. 5 is an exploded view showing the preferred embodiment in the zero position. 
     FIG. 6 is an exploded view of Embodiment 2 in the zero position. 
     FIG. 7 is an exploded view of Embodiment 2 in the 180 position. 
     FIG. 8A is an exploded view of Embodiment 3 in the zero position. 
     FIG. 8B is an exploded view of Embodiment 3 in the 180 position. 
     FIG. 9A is an exploded view of Embodiment 4 in the zero position. 
     FIG. 9B is an exploded view of Embodiment 4 in the 180 position. 
     FIG. 10A is an exploded view of Embodiment 5 in the zero position. 
     FIG. 10B is an exploded view of Embodiment 5 in the 180 position. 
     FIG. 11 is an isometric view of Embodiment 6 in the zero position. 
     FIG. 12 is an exploded view of Embodiment 6 in the zero position. 
     FIG. 13A is a front cross-section view of Embodiment 6 in the zero position. 
     FIG. 13B is a front cross-section view of Embodiment 6 in the 180 position. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Terminology 
     The following terms are used in this document and have specific meanings: 
     The platform. The upper surface of the swivel device. 
     Zero degree position. This is the normal operating position. For computer equipment, the video screen or the front panel face the operator in this position. 
     180 degree position. This is the service position. In this position, the back of the computer faces the operator, allowing access to cables, replaceable computer cards, and the like. 
     Cable entry point. The area at which the cable from the computer equipment enters the invention. The cable entry point rotates with the platform. 
     Cable exit point. The area near the back of the invention from which the cable emerges and then travels to the outside world. The cable exit point is stationary. 
     Cable service length. The cable length from the cable entrance point to the cable exit point. 
     Component. Used interchangeably with electrical equipment. 
     Description of Preferred Embodiment 
     This invention is a swivel device for cable-connected equipment. FIG. 1 shows the prior art, wherein an operator  10  attempts to gain access to the back of the electrical components  20 , in this case a computer system, by sliding them across the work surface  24 . There are numerous cables  30  attached, which may be pulled, damaged, or tangled during this operation. 
     FIGS. 2 and 3 show a preferred embodiment of this invention in the zero position (the operating position). FIG. 4 shows the invention in the 180 position (the service position). For all embodiments shown herein, the rotating convention is that the platform, when viewed from above, is turned clockwise to attain the service position and counter-clockwise to restore it to the operating position. One skilled in the art will see that other embodiments are possible. 
     The invention comprises a platform  40  that rests rotatably upon a stationary base  42 , the platform being spaced a predetermined height above a cable supporting surface  44 . The platform and base define a wiring cavity  46  substantially the shape of a low-profile parallelepiped. 
     To assist the operator in setting up the invention, the base  42  may have a marking  48  indicating the front, the front being the side facing the user. The platform may also have a marking  50  indicating the side facing the user in the normal operating position. The platform marking assists the operator in orienting the equipment when placing it on the platform. 
     The swivel bearing assembly consists of a plurality of load bearing rollers  52 ,  54 , and  56 . The rollers travel on a race  58  on the stationary base  42 . The roller diameter defines the height of the wiring cavity, and must be sufficient to allow unobstructed passage of a cable through the cavity. In this embodiment, the rollers are approximately 2.5 inches in diameter, resulting in a cavity height of approximately 2.25 inches. 
     In this embodiment, the cable supporting surface  44  consists of two separate surfaces: a rotating lower disk  60  and the upper part of the base  42  around the periphery of the lower disk. The cables  30  traverse the cable supporting surface from the cable entry point  62  to the cable exit point  64 . The path length of the cable traversing the invention is referred to as the cable service length. The cables must be at least as long as the cable service length. 
     A post  76  and columns  68  and  70  are attached to the lower disk  60  and are spaced uniformly around the perimeter of the disk. The purpose of the columns is to contain the rollers  52 ,  54 , and  56  and to locate them at 120 degree intervals. The columns are not load bearing. An upper disk  72  is attached to the columns, completing the center assembly  74 . A purpose of the center assembly is to rotatably fasten the platform to the base. 
     In this embodiment, the rollers can be shown to travel at one half the angular rotation of the platform as viewed from the top. Therefore, the center assembly  74 , which is urged to rotate by the rollers, also rotates at one-half the angle of the platform. 
     FIGS. 3 and 4 show a post  76  of predetermined shape and position that controls the cables  30 . The post is positioned a predetermined distance from the axis of rotation  78  of the invention. The post has a smooth surface  80  around which the cables wrap in the normal operating position. The post substantially contacts the center area of the cable passing through the invention. 
     A cable  30  originating at the back of the equipment  20  (shown in FIG. 1) travels the following path: The cable passes downward from the equipment and enters the wiring cavity  46  between the platform  40  and the cable support surface  44 . The cable enters the cavity at a cable entrance point  62 . 
     When the platform  40  is in the operating position (FIG.  3 ), the cable  30  travels in a substantially U-shaped path in a horizontal plane, and then travels toward the back of the base  42 . The cable then exits the cavity  46  at a stationary cable exit point  64 . 
     When the platform  40  is in the service position (FIG.  4 ), the cable  30  travels in a nominally straight path in a horizontal plane toward the back of the base  42 . The cable then exits the cavity at the previously described exit point  64 . 
     In this embodiment, the post  76  is approximately 1.75 inches from the axis of rotation  78  of the invention, resulting in a substantially constant cable service length throughout the rotation of the platform. The cable service length is equal to the diameter of the arc swept out by the cable entrance point  62  during rotation of the platform  40 . Since cable service length is substantially constant, there is negligible pulling on the cable  30  throughout the range of rotation. It has been determined experimentally that for flexible cables, this arrangement also produces negligible sideways movement of the cables at the cable exit point  64  when the platform  40  is rotated; therefore, cable clamps are not typically required. The precise position of the cable exit point is determined by the cable&#39;s direction of travel as it passes to the destination device. 
     FIGS. 3 and 4 also show stops  82  and  84  that limit the rotation of the platform. The stops may limit the rotation of the platform  40  at zero degrees and at 180 degrees, or they may be configured for a wider range, nominally minus 15 degrees and 180 degrees. The wider range allows the equipment to be rotated left and right through a 30 degree angle during operation (or plus and minus 15 degrees using the terminology in this document). This capability allows for modest adjustment of viewing angle about the vertical axis for video monitors or other display devices. 
     To one skilled in the art, a number of stop embodiments are possible. In this embodiment, two sets of stops  82  and  84  are used. Each stop mechanism permits a platform  40  travel of nominally 90 degrees, resulting in a total travel of 180 degrees. Alternatively, each stop mechanism may be set to 97.5 degrees, providing plus and minus 15 degrees of travel in the normal operating position to allow adjustment of monitor viewing position. 
     For this embodiment, the invention is operated as follows: The cables  30  must be unattached at one end for installation, and they are most easily installed in the 180 position, at which time the operator may pass the cable free ends through the invention in a substantially straight line. The operator then returns the platform  40  to the zero position, which automatically guides the cables around the post  76 . This operation can be performed while sitting down. 
     Description of Additional Embodiments 
     FIGS. 6 and 7 show another embodiment of this invention, herein labeled Embodiment 2. The rotating means is implemented by ball bearings  86  instead of rollers. This embodiment has the following similarities to the preferred embodiment: The cable supporting surface  44  is substantially a rotating lower disk  60 . Post  76 , columns  68  and  70 , the upper disk  72 , and the lower disk  60  comprise a center assembly  74 . As previously described, a purpose of the center assembly is to rotatably connect the platform to the base. However, a significant difference in this embodiment is that the center assembly is load-bearing. 
     As in the preferred embodiment, the center section rotates at one-half the angle of rotation of the platform  40 . A gear mechanism  88  may be included to accurately locate the rotational position of the center assembly. 
     FIGS. 8A and 8B show another embodiment of this invention, herein labeled Embodiment 3. In this embodiment, the post  76  supports the computer by cantilever effect and no additional supports are used. As in the preferred embodiment, the cable supporting surface  44  is substantially a rotating circular plate  92 . The post  76  is fabricated from sheet steel rolled into a “U” shape. The upper part is welded to a strengthening plate  90  in the upper deck and the lower part is welded to a circular plate  92  that rests on the bearing assembly  94 . 
     This embodiment differs from the preferred embodiment in that the cable supporting surface and the post rotate at the same angle as the Platform. 
     In this embodiment, cable loading is more convenient, as it is not necessary to disconnect the cables at one end. Further, with this embodiment, cable loading can be performed at any degree of rotation. 
     FIGS. 9A and 9B show another embodiment of this invention, herein labeled Embodiment 4. As in the previous embodiment, the post  76  supports the computer by cantilever effect and no additional supports are used. The post is fabricated from sheet steel and the upper part is welded to a strengthening plate  90  in the upper deck. The lower part is welded to a drum-shaped disk  96  having a downward-facing cavity that contains a plurality of rollers  98 . The rollers rest on the work surface  24 , the work surface for this embodiment being functionally equivalent to a base. The rollers are circularly arranged and constrain the Platform (strengthening plate  90 ) to a rotating motion. 
     As in the previous embodiment, the cable supporting surface and the post rotate at the same angle as the Platform. In operation, this embodiment also facilitates loading cables, and it is not necessary to disconnect cables at either end. 
     FIGS. 10A and 10B show another embodiment of this invention, herein labeled Embodiment 5. In this embodiment, the post  76  supports the computer by cantilever effect and no additional supports are used. The post is fabricated from sheet steel and the upper part is welded to a circular plate  93  that supports the bearing assembly  94 . The lower part is welded to the base  42 . In this embodiment, the cable supporting surface is the same as the base and is stationary. 
     FIGS. 11,  12 ,  13 A and  13 B show another embodiment of this invention, herein labeled Embodiment 6. Both figures are shown in the zero position. In this embodiment, the base  42  has a stationary surface  44  traversed by the cable  30  (not shown). The platform  40  rotates upon a ball bearing assembly  94  and is supported by one curved stationary support  100  and one curved movable support  102 . The ball bearing assembly rests on a support plate  93 , which is attached to and supported by the stationary support  100 . Additionally, the platform is attached to and supported by a curved, rotatable support  102 . This support rests on a ball bearing assembly  104  which further rests on the base  42 . In the operating position, the curved supports are opposed to one another as viewed from the top; in the service position, they are in a nesting configuration. In the service position, the platform is supported by cantilever effect; in the operating position, it is not. 
     This embodiment is shown with a post  76 ; however, clamps may be used instead as the cable controlling means. In this embodiment, clamps at the cable entrance point  62  (not shown) and the cable exit point  64  (not shown) could control the cable position and ensure that the cable service length in the normal operating position is equal to the service length in the service position. 
     In summary, these embodiments provide a stable rotating platform for computer equipment that may be rotated 180 degrees for servicing, and may provide approximately 30 degrees of adjustment in the normal position for optimizing viewing angle. The horizontal cable path results in a low profile swivel device. 
     The embodiments of the invention described above are to be regarded as examples only and a number of other modifications and embodiments are possible within the scope of the appended claims.