Abstract:
A modular hinge includes a clutch module coupled to an extension arm for supporting an enclosure, such as a display enclosure for a portable computer. The clutch module and extension arm are fabricated as separate parts, and then assembled together to form essentially one permanent hinge. This arrangement allows the extension arm of the hinge to by-pass the prehardening heat treatment, which is required for the clutch module.

Description:
FIELD OF THE INVENTION 
     The present invention relates to hinges for mechanically supporting two objects in a rotational orientation. In particular, the present invention relates to a modular hinge arrangement that structurally supports portable computer displays. 
     BACKGROUND OF THE INVENTION 
     Monitors or displays for portable computers are usually mounted in display enclosures, which are in turn mounted to the base of the computer with hinges. The display enclosures are usually constructed of a lightweight material such as molded plastic, which is capable of adequately supporting and protecting the monitor despite being subject to rough handling. The hinges are typically attached by screws or other fasteners directly to the plastic display enclosure. 
     Consumers typically want the largest possible display that they can afford in a computer system. This is as true with portable computers as it is with desktop computers. As portable computer displays become larger, the weight of the larger display causes additional stress on the hinges and the places where the hinge attaches to the computer base and display enclosure, often resulting in cracks. To solve this problem, manufacturers have increased the surface area of the hinge with an extension arm to alleviate the localization of stress. The difficulty, however, is that the manufacturing yield for such a hinge is low due to the tendency of the arm to distort during the normal prehardening process, which involves heat treatment. 
     In addition, because of the desirability of larger monitors, manufacturers often upgrade existing portable computer product lines by increasing the monitor size. The problem with this type upgrading is that it requires the computer base and hinge arrangement to be re-designed in the upgraded model to support the larger monitor. Once the base and hinge designs are modified, then new tooling must be performed before manufacturing can begin. It would be desirable if a modular hinge design could be developed that would permit monitors of various sizes to couple to the portable computer base, without requiring the base or hinge to be re-designed and re-tooled. 
     SUMMARY OF THE INVENTION 
     The present invention, constructed in accordance with the preferred embodiment, includes a hinge arrangement that attaches a portable computer base to display units of various sizes and weights. The hinge arrangement preferably employs a modular design that permits various size displays to be easily and securely attached to the base, while also reducing stress in the immediate vicinity of the hinge. The hinge arrangement described in the preferred embodiment includes two modules that are relatively easy to assemble, and relatively low-cost. 
     In accordance with the preferred embodiment, a modular hinge includes a clutch module and a stress dispersing module which are fabricated as separate parts, and then assembled together to form essentially one permanent hinge. Relative movement (both laterally and vertically) between the clutch module and the stress dispersing module are prevented by the rigid association between the two parts. In the preferred embodiment, the stress dispersing module includes an extension arm. The modularity of the hinge allows the extension arm to by-pass the prehardening heat treatment process, thus increasing the manufacturing yield for this component. The extension arm attaches to the display enclosure. As the size and weight of the monitor and display enclosure changes, the length of the extension arm can be modified if necessary to provide the necessary support for the new monitor size. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevated perspective view of the hinge and extension arm constructed in accordance with the preferred embodiment of the present invention; 
     FIG. 2 is an exploded view of the hinge and extension arm of FIG.  1 . 
     FIG. 3 is an enlarged elevated view showing the insertion of the hinge in the extension arm of FIG.  2 . 
     FIG. 4 is a perspective view of the hinge attached to a display panel and base of a computer according to the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring initially to FIG. 1, a modular hinge constructed in accordance with the preferred embodiment generally comprises a clutch module  20  and a stress dispersing module  22 , including an extension arm  25 . If the modular hinge is used for attachment of a display unit onto the base of a portable computer, the clutch has one end adapted for attachment to the computer base with screws through attachment holes  23 . Arm  25  is adapted for attachment to the display enclosure with screws (not shown) through side holes  24 . In this way, the stress of supporting the weight of the display is dispersed to the various attachment points along the length of the arm  25 . 
     FIGS. 2 and 3 show in greater detail the manner in which the clutch module  20  and the stress dispersing module  22  are secured together in the preferred embodiment of the present invention. The clutch module  20  preferably is fabricated in two parts, which comprise an adapter  28  and a mounting member  30 . In the preferred embodiment, both parts are pre-hardened by heat treatment before assembly. 
     As shown in the preferred embodiment of FIGS. 2 and 3, the adapter  28  has a flat, rectangular end portion  32  with two screw holes  23  for fastening to the side of the base of the computer. The adapter  28  also preferably includes a shaft  34  extending from the base of the adapter  28 . The longitudinal axis of shaft  34  preferably is perpendicular to the of the rectangular end portion  28  and defines the axis of rotation of the attached display enclosure. 
     The mounting member  30  preferably includes a mounting plate  36  and a bracket  38 . Bracket  38  is adapted to receive shaft  34  such that mounting plate  36  may rotate around the longitudinal axis of shaft  34 . In the preferred embodiment, the mounting plate  36  includes two through holes  40  and two mounting holes  42 . The mounting holes  42  preferably receive screws or other fasteners (not shown) for mounting the hinge on the display enclosure. The end of the mounting plate  36  distal the bracket  38  is also provided with a lug  44 . 
     As best seen in FIG. 2, the long extension arm  25  of the stress dispersing module  22  preferably includes a bracing end  46 , which has a planar surface  48  for interaction with the mounting plate  36 . The planar surface  48  is stamped with two dimples  50 , two holes  52  and a slot  54  which is adapted to receive lug  44  fittingly. As shown in FIG. 3, the mounting plate  36  is adapted to be superimposed above planar surface  48  with holes  42  superimposed upon holes  52 , and the back of the two dimples  50  inserted into through holes  40 . The bracing end  46  includes a flange  60  with slot  54 . The flange  60  defines a shoulder for receiving the distal end of the mounting plate  36 , with slot  54  positioned perpendicular to the plane of the planar surface  48 , so that lug  44  may be locked inside slot  54 . The lateral sides  56  and  58  of the planar surface  48  preferably are folded up and around the mounting plate  36  such that they act as clamps to keep the two hinge modules securely together. 
     After the adapter  28  and the mounting member  30  are pre-hardened, the hinge is assembled by inserting the shaft  34  into bracket  38  and superimposing mounting plate  36  onto the planar surface  48  of the bracing end  46  such that the back of dimples  50  are inserted into through holes  40 , thus preventing lateral movement between the two modules. The flange  60  of the planar surface  48  is then folded up to form a perpendicular shoulder, with slot  54  locking onto lug  44 , to prevent the rotational force of the hinge from forcing the two modules apart. The two lateral sides  56  and  58  of the planar surface  48  are also wrapped around the mounting plate  36  to prevent the dimples  50  from slipping out of through holes  40 . 
     Referring lastly to the embodiment as shown in FIG. 4, the present invention is applied to a portable computer whereby the extension arm  25  of the present hinge is fastened onto display panel  66 , while the rectangular end portion of the adapter  32  is attached to the base  68  of the portable computer. 
     From the description above, it is clear that there are numerous benefits to the modular approach to hinge joints. When the size of the display unit changes, time and costs for tooling new parts may be reduced since the same clutch module  20  may be used, and only the stress dispersing module  22  needs to be changed. Furthermore, since pre-hardening is not required for the stress dispersal module  22 , structural distortion due to the heat treatment process is eliminated, and production efficiency is increased. It is also clear that although the present invention has been described particularly with references to the aforementioned figures with emphasis on a hinge for the display enclosure of a portable computer, the method and apparatus of the present invention has utility in many applications where hinged connections are required. Example include but not are not limited to photocopying machines, electronic organizers and mobile electronic equipment, among others.