Abstract:
The hinge system for a portable computer for pivotably securing a top cover to a base unit includes a first base unit hinge member for mounting to the base unit. The first base unit hinge member has proximal and distal mounting portions which are angled relative to each other. The proximal and distal mounting portions are each securable to a surface of the base unit for distributing stress exerted on the base unit by the first base unit hinge member. A first pivoting top cover hinge assembly is secured to the first base unit hinge member. The first top cover hinge assembly mounts to the top cover.

Description:
This application is a continuation of application Ser. No. 09/148,740, filed Sep. 4, 1998, now issued U.S. Pat. No. 6,202,256 B1. 
    
    
     BACKGROUND 
     Portable computers such as notebook computers typically have a plastic top cover for housing and protecting a flat-panel display. In most cases, the flat-panel display is secured to the back or rear surface of the top cover. Along one edge of the top cover, the top cover is pivotably secured to a base unit with two hinges. The base unit usually has a plastic base unit housing to which the hinges are mounted and includes a keyboard on the upper surface of the base unit. The hinges allow the top cover to be opened and closed over upper surface (and hence the keyboard) of the base unit. When in the closed position, the top cover protects both the flat-panel display and the keyboard. To use the computer, the top cover is pivoted upwardly and tilted backward, relative to the base unit, to allow visual access to the flat-panel display and physical access to the keyboard. 
     SUMMARY OF THE INVENTION 
     Often, the top cover twists while pivoting. Twisting of the top cover can bind the hinges and inhibit the ability of the top cover to pivot smoothly. In addition, since the hinges are typically mounted to plastic surfaces of the base unit housing, alternating forces exerted onto those plastic surfaces by the hinges can fatigue the plastic over time and result in breakage. 
     The present invention is directed to a hinge system for a portable computer for pivotably securing a top cover to a base unit while preventing twisting of the top cover and breakage of the base unit housing. The hinge system includes a first base unit hinge member for mounting to the base unit. The first base unit hinge member has proximal and distal mounting portions which are angled relative to each other. The proximal and distal mounting portions are each securable to a surface of the base unit for distributing stress exerted on the base unit by the first base unit hinge member. A first pivoting top cover hinge assembly is secured to the first base unit hinge member. The first top cover hinge assembly mounts to the top cover. 
     In preferred embodiments, the first top cover hinge assembly includes a lower pivoting piece mounted to the first base unit hinge member. The lower pivoting piece is pivotably secured to an elongate stiffening member. The elongate stiffening member is secured to the top cover to stiffen the top cover. Specifically, the lower pivoting piece is pivotably mounted to an upper pivoting piece by a shaft. The upper pivoting piece is secured to the elongate stiffening member. The lower pivoting piece includes a tongue for insertion into a cavity within the first base unit hinge member for securing thereto. The lower pivoting piece further includes a mounting flange for securing to a top surface of the first base unit hinge member. The tongue and mounting flange are secured to the first base unit hinge member by fasteners oriented at right angles to each other. 
     The present invention hinge system typically includes a second base unit hinge member for mounting to the base unit spaced apart from the first base unit hinge member. The second base unit hinge member has proximal and distal mounting portions which are angled relative to each other. The proximal and distal mounting portions are each securable to a surface of the base unit for distributing stress exerted on the base unit by the second base unit hinge member. A second pivoting top cover hinge assembly is secured to the second base unit hinge member for mounting to the top cover spaced apart from the first top cover hinge assembly. The second top cover hinge assembly includes a lower pivoting piece mounted to the second base unit hinge member. The lower pivoting piece is pivotably secured to an elongate stiffening member for securing to the top cover to further stiffen the top cover. The first and second base unit hinge members are typically mounted to first and second corners of the base unit. The proximal and distal mounting portions of the base unit hinge members are preferably at right angles to each other and are secured to a bottom panel of the base unit. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. 
     FIG. 1 is a perspective view of a portion of the base unit housing of a notebook computer pivotably secured to the top cover by the present invention hinge system. 
     FIG. 2 is a plan view of the left-hand base unit hinge member mounted at the left-hand corner of the base unit housing. 
     FIG. 3 is a plan view of the right-hand base unit hinge member mounted at the right-hand corner of the base unit housing. 
     FIG. 4 is a rear view of a portion of the left-hand hinge with the base unit housing and top cover being in section. 
     FIG. 5 is a cross-sectional view of the upper pivoting hinge piece and a portion of the stiffening member of the left-hand top cover hinge assembly mounted to the top cover taken along lines  5 — 5  of FIG.  4 . 
     FIG. 6 is a cross-sectional view of the upper pivoting hinge piece and a portion of the stiffening member of the left-hand top cover hinge assembly mounted to the top cover taken along lines  6 — 6  of FIG.  4 . 
     FIG. 7 is a cross-sectional view of the left-hand top cover stiffening member taken along lines  7 — 7  of FIG.  1 . 
     FIG. 8 is a cross-sectional view of the right-hand top cover stiffening member taken along lines  8 — 8  of FIG.  1 . 
     FIG. 9 is a cross-sectional view of the right-hand top cover stiffening member taken along lines  9 — 9  of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, the present invention hinge system  18  pivotably secures the top cover  14  of notebook computer  10  to the base unit housing  12 . Hinge system  18  consists of a left-hand hinge  18 L and a right-hand hinge  18 R. Left-hand hinge  18 L includes a left-hand base unit hinge member  20 L mounted to bottom panel  12   a  of base unit housing  12  at the rear left-hand corner of the base unit housing  12  and a left-hand top cover hinge assembly  19 L mounted to the back panel  14   a  of top cover  14  at the left-hand side of top cover  14 . Right-hand hinge  18 R includes a right-hand base unit hinge member  20 R mounted to bottom panel  12   a  at the rear right-hand corner of the base unit housing  12  and a right-hand top cover hinge assembly  19 R mounted to panel  14   a  at the right-hand side of top cover  14 . 
     Base unit hinge members  20 L/ 20 R are generally “L” shaped and are secured to bosses  42  extending from the bottom panel  12   a  of base unit housing  12 . Left-hand base unit hinge member  20 L has a leg  20   a  extending adjacent to the rear wall  12   d  of base unit housing  12  and a leg  20   b  extending at a right angle from leg  20   a  adjacent to sidewall  12   c . Right-hand base unit hinge member  20 R also has a leg  22   a  extending adjacent to the rear wall  12   d  and a leg  22   b  extending at a right angle from leg  22   a  adjacent to sidewall  12   b . The “L” shape of base unit hinge members  20 L/ 20 R distributes stresses exerted by hinges  18 L/ 18 R over a large enough region of base unit housing  12  so that the plastic material of base unit housing  12  does not fatigue and break. 
     Each top cover hinge assembly  19 L/ 19 R includes a lower pivoting hinge piece  24  and an upper pivoting hinge piece  32  which are pivotably coupled together by a shaft  28 . A tongue  24   a  extends downwardly from each lower hinge piece  24  and is coupled to a respective base unit hinge member  20 L/ 20 R within slots  62  extending through the top surface of base unit hinge members  20 L/ 20 R. A horizontal flange  24   b  adjacent to tongue  24   a  is also secured to the top surface of each base unit hinge member  20 L/ 20 R. Left-hand and right-hand top cover hinge assemblies  19 L/ 19 R include respective stiffening members  36  and  38  for stiffening top cover  14 . Stiffening members  36 / 38  are secured to panel  14   a  of top cover  14  and to respective upper hinge pieces  32 . Stiffening members  36 / 38  extend along the left and right sides of the top cover  14  which sufficiently stiffens top cover  14  to prevent twisting of the top cover  14  when pivoted. 
     In operation, twisting of top cover  14  (depicted by arrows a and b in FIG. 1) caused by the user pivoting top cover  14  to open or close top cover  14  in the direction of arrows e is resisted by stiffening members  36 / 38 . The addition of stiffening members  36 / 38  provides top cover  14  with enough rigidity to allow top cover  14  to pivot about horizontal axis “X” and hence open and close smoothly without twisting and binding the hinge system  18 . The opening and closing of top cover  14  exerts alternating forces on base unit hinge members  20 L/ 20 R in the direction of arrows c and d (FIGS.  2  and  3 ). These alternating forces are in turn transferred by base unit hinge members  20 L/ 20 R onto base unit housing  12 . Movement of base unit hinge members  20 L/ 20 R towards the front and rear of base unit housing  12  is resisted by legs  20   b / 22   b  of base unit hinge members  20 L/ 20 R which extend in the same direction as the forces. The “L” shape of base unit hinge members  20 L/ 20 R provided by legs  20   a / 20   b  and  22   a / 22   b  distribute stresses over surfaces of bottom panel  12   a , sidewalls  12   b / 12   c  and rear wall  12   d  adjacent to as well as between legs  20   a / 20   b  and  22   a / 22   b . This reduces the stresses exerted on base unit housing  12  by hinge system  18  to low enough levels to prevent fatigue and breakage of base unit housing  12 . The proximity of legs  20   a / 20   b  and  22   a / 22   b  to walls  12   b  through  12   d  allows the stresses to be spread over walls  12   b  through  12   d  as well as over bottom panel  12   a.    
     A more detailed description of hinge system  18  now follows. Referring to FIGS. 1,  2  and  3 , base unit hinge members  20 L/ 20 R are secured to bosses  42  extending upwardly from bottom panel  12   a  of base unit housing  12  with screws  44  through holes  60  in mounting flanges  64 . Each base unit hinge member  20 L/ 20 R has three mounting flanges  64 . Two flanges  64  are located at the far ends of legs  20   a / 20   b  and  22   a / 22   b  while the third flange  64  is located at the junction of legs  20   a / 20   b  and  22   a / 22   b . The legs  20   a / 20   b  and  22   a / 22   b  of base unit hinge members  20 L/ 20 R each have a portion raised above flanges  64  which allows various computer components to be positioned underneath base unit hinge members  20 L/ 20 R. For example, a small circuit board  46  is shown positioned under leg  20   a  of base unit hinge member  20 L in FIG.  1  and I/O ports  48 ,  50  and  52  are shown positioned under leg  22   a  of base unit hinge member  20 R in FIGS. 1 and 3. A flex circuit  68  (FIG. 2) in electrical communication with circuit board  46  is allowed to pass between leg  20   a  and rear wall  12   d  of base unit housing  12 . FIG. 3 also depicts a push button  72  extending under leg  22   b  of base unit hinge member  20 R. In addition, legs  20   a / 22   a  extend upwardly above bottom panel  14   a  for securing with top cover hinge assemblies  19 L/ 19 R. A portion of leg  20   b  of base unit hinge member  20 L abuts sidewall  12   c  for increased stability. A portion  22   c  of leg  22   b  extends downwardly into contact with bottom panel  12   a  and provides increased stability for base unit hinge member  20 R since leg  22   b  does not abut sidewall  12   b.    
     FIG. 4 is a rear view depicting the manner in which left-hand hinge  18 L is secured to base unit housing  12  and top cover  14 . Right-hand hinge  18 R is secured to base unit housing  12  and top cover  14  in a similar fashion such that a separate discussion directed to right-hand hinge  18 R is unnecessary. Tongue  24   a  of lower hinge piece  24  is secured to base unit hinge member  20 L within slot  62  of leg  20   a  with two horizontally oriented screws  44  through holes  70  and  71 . Tongue  24   a  has a protrusion  23  which engages a small slot  26  at the bottom of slot  62 . Mounting flange  24   b  of lower hinge piece  24  is secured to the top of leg  20   a  adjacent to slot  62  with two vertically oriented screws  44  through holes  56  and  58 . As can be seen, holes  70 / 71  and  56 / 58  extend along axes which are perpendicular to each other. This arrangement allows base unit hinge members  20 L/ 20 R and top cover hinge assemblies  19 L/ 19 R to be first secured to the base unit housing  12  and top cover  14 , respectively, and then secured together later. 
     Lower hinge piece  24  is rotatably mounted onto shaft  28 . Shaft  28  is fixed within upper hinge piece  32  by a sleeve  28   a  and extends from the sidewall  14   b  of top cover  14  through a hole  28   a . Stiffening member  36  is secured to upper hinge piece  32  by screws  44  through the two lower holes  54  in the lower portion  36   a  of stiffening member  36 . The same two screws  44  extend through upper hinge piece  32  into bosses  42  extending from panel  14   a  to secure upper hinge piece  32  to top cover  14 . The lower portion  36   a  of stiffening member  36  is further secured to top cover  14  with two screws  44  extending through the two upper holes  54  of lower portion  36   a  into bosses  42  extending from panel  14   a  (FIGS.  5  and  6 ). The upper portion  36   b  of stiffening member  36  is secured to top cover  14  with screws  44  through holes  54  into bosses  42  (FIG. 1) extending from panel  14   a.    
     The lower portion  36   a  of stiffening member  36  is properly positioned relative to upper hinge piece  32  by two protrusions  32   a  extending from upper hinge piece  32  through locating holes  33  within the lower portion  36   a  of stiffening member  36  (FIGS. 1,  4  and  5 ). Furthermore, upper hinge piece  32  is properly positioned relative to top cover  14  by a protrusion  78  extending from panel  14   a  through hole  76  within upper hinge piece  32  and hole  33  in lower portion  36   a  (FIGS. 1,  4  and  6 ). 
     Referring to FIGS. 7,  8  and  9 , stiffening members  36  and  38  are preferably fabricated from sheet metal. The upper portion  36   b  (FIG. 7) of stiffening member  36  includes top  80  and side  82  walls which are bent at right angles to each other for stiffness. A lower flange  84  is bent relative to sidewall  82 . Lower flange  84  contacts panel  14   a  of top cover  14  for providing maximum stiffness. Referring to FIG. 8, the upper portion  38   b  of stiffening member  38  includes a top wall  86  which is slightly wider than top wall  80  of stiffening member  36 . The upper portion  38   b  of stiffening member  38  also includes a mid-portion  38   c  (FIGS. 1 and 9) which does not have a top wall  86  so that circuitry  40  can be located adjacent to mid-portion  38   c . A brace  38   d  (FIG. 1) extends from upper portion  38   b  over circuitry to stabilize mid-portion  38   c  of stiffening member  38 . 
     In one preferred embodiment, left-hand base unit hinge member  20 L has a width W 1  of about 2¼ inches and a length L 1  of about 3¼ inches (FIG.  2 ). Right-hand base unit hinge member  20 R has a width W 2  of about 2⅛ inches and a length L 2  of about 2⅜ inches (FIG.  3 ). In addition, legs  20   a / 22   a  are about ¾ of an inch in height while legs  20   b / 22   b  are about ⅜ of an inch in height. Lower hinge pieces  24  are about 1 inch long and {fraction (9/16)} inches high while upper hinge pieces  32  are about ⅞ inches long and {fraction (9/16)} inches high. Hinge members  20 L/ 20 R and hinge pieces  24 / 32  are preferably die cast from zinc or zinc alloy, but alternatively, can be made of other suitable metals. 
     Stiffening members  36 / 38  are formed from sheet metal about 0.025 inches thick and are about 9⅛ inches long. Top wall  80  of stiffening member  36  is about 0.23 inches wide and top wall  86  of stiffening member  38  is about 0.30 inches wide. Sidewalls  82  are about 0.18 inches high and flanges  84  are about 0.10 inches wide. Although particular dimensions have been discussed above, such dimensions can vary depending upon the exact dimensions of the notebook computer  10 . 
     Equivalents 
     While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described specifically herein. Such equivalents are intended to be encompassed in the scope of the claims. 
     For example, the base unit hinge members  20 L/ 20 R can be secured to the walls  12   b - 12   d  of base unit housing  12 . In addition, the base unit hinge members  20 L/ 20 R can be formed to more completely contact bottom panel  12   a  or walls  12   b - 12   d . Furthermore, the hinge system can be made such that the base unit hinge members include pivoting hinge pieces. Finally, the stiffening members  36 / 38  in top cover  14  can be formed from rods, bars, tubing and the like as in the purview of one skilled in the art.