Patent Publication Number: US-2007119025-A1

Title: Hinge assembly for flat display monitor

Description:
1. FIELD OF THE INVENTION  
      The present invention generally relates to a hinge assembly and, particularly, to a hinge assembly for a flat display monitor.  
     2. DISCUSSION OF THE RELATED ART  
      With the widespread use and the variety of computers available, display devices configured for such a variety of computers also come in a variety of sizes, shapes, and weight. In general, a typical cathode-ray tube (CRT) monitor includes a display panel for displaying an image, a vacuum tube coupled to the rear of the display panel, and an electron gun coupled to the rear of the vacuum tube. This configuration is a huge factor in limiting the total volume and final weight of the CRT monitor. In addition to the problem mentioned above, the CRT monitor carries a huge problem in that a user is easily fatigued when looking at the CRT monitor over long hours due to its low image quality. It is this problem alone that many people switched to using a flat screen display monitor, e.g., Liquid Crystal Display (LCD) monitor, from the conventional CRT monitors. Such flat display monitors generally offer the advantages of a greatly reduced size and weight properties including the ability to produce a high image quality. Furthermore, flat screen display monitors may help to overcome space limitations through folding over (such as with a laptop computer) or rotating (such as with a desktop monitor) so as to facilitate adjustment of the position thereof relative to the user.  
      The rotating or folding-over functions of the flat display monitor are realized with a hinge assembly. A hinge assembly includes an L-shaped fixed seat, a pivotal axle, and multiple oiled washers. The fixed seat has a retaining hole defined thereof. The pivotal axle is pivotally connected with the fixed seat. The pivotal axle has a retaining shoulder formed at a middle portion thereof, a connecting end portion integrally formed at a first end of the retaining shoulder, and a fixing end portion integrally formed at a second end of the retaining shoulder. The connecting end portion of the pivotal axle is extended through a retaining hole of the fixed seat along with multiple oiled washers, and then fastened by a fastening piece. However, in use, it is needed to use great efforts to rotate the hinge assembly, since a greater force is exerted thereon. As a result, it is inconvenient for a user to operate the hinge assembly.  
      Therefore, a new hinge assembly is desired in order to overcome the above-described shortcomings.  
     SUMMARY  
      In one embodiment thereof, a hinge assembly includes a support seat, a base seat and a pivot mechanism. The support seat defines a pivoting hole. The base seat defines an engaging hole. The pivot mechanism rotatably connects the support seat to the base seat. The pivot mechanism includes an irregular-holed tab washer defining an irregular hole and a pivotal shaft. The irregular-holed tab washer is non-rotatably mounted to the support seat. The pivotal shaft non-rotatably engages in the engaging hole of the base seat and rotatably engages in the pivoting hole of the support seat. The irregular-holed tab washer surrounds the pivotal shaft. The pivotal shaft engages with the irregular hole of the irregular-holed tab washer for limiting a rotation angle between the support seat and the base seat.  
      Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Many aspects of the hinge assembly can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the hinge assembly. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
       FIG. 1  is an isometric view of an embodiment of a hinge assembly, as used in a flat display monitor;  
       FIG. 2  is an exploded, isometric view of the hinge assembly in  FIG. 1 ;  
       FIG. 3  is an assembled, isometric view of the hinge assembly in  FIG. 2  viewed from a first direction;  
       FIG. 4  is similar to  FIG. 3 , but viewed from a second direction; and  
       FIG. 5  is a cut-away view taken along line V-V of  FIG. 4 . 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
      Referring to drawings in detail,  FIG. 1  shows a flat display monitor employing a hinge assembly  300  in accordance with an embodiment of the present application. The flat display monitor is taken here as an exemplary application, for the purposes of describing details of the hinge assembly  300 . It is to be understood, however, that the hinge assembly  300  could be advantageously used in other environments (e.g. cabinet doors). As such, although providing particularly advantages when used in flat display monitors, the hinge assembly  300  should not be considered limited in scope solely to an intended use environment of flat display monitors. A hinge assembly  300  is illustrated in the flat display monitor as shown in  FIG. 1 . The flat display monitor includes a display unit  100  and a support body  200 . The hinge assembly  300  connects the display unit  100  to the support body  200  so that the display unit  100  can be pivoted relative to the support body  200 .  
      Referring to  FIG. 2 , the hinge assembly  300  includes a support seat  10 , a base seat  20 , and two pivot mechanisms  30  each including a pivotal shaft  31 , a pin  34 , an irregular-holed tab washer  41 , a tab washer  42 , two D-hole washers  51  and  52 , a pair of spring/cupped washers  61  and  62 , a resilient element  70 , a limiting washer  80 , and a screw nut  90 .  
      The support seat  10  includes a mounting portion  12 , a connecting portion  14 , and two extending portions  16 . The mounting portion  12  and the connecting portion  14  are substantially boards with the connecting portion  14  being thicker than the mounting portion  12 . The mounting portion  12  has a surface  120  and defines a plurality of mounting holes  122 . In this embodiment, there are four mounting holes  122 . The support seat  10  is mounted to the support body  200  by means of the mounting holes  122 . An end of the connecting portion  14  is connected to the mounting portion  12  and another opposite end forms two protrusions  142  and two extending portions  16 . Each of the protrusions  142  is configured to be a triangular prism shaped like. The protrusions  142  are configured to be in between the two extending portions  16  that are slanted toward the surface  120 . Each extending portions  16  forms a cylinder and defines a central pivoting hole  160  and a pinhole  166  adjacent to the pivoting hole  160 . An end of each extending portion  16  defines a washer housing depression  162  and another opposite end of each extending portion  16  defines a washer housing depression  163 . Each extending portion  16  further defines two opposite receiving slots  164  at a periphery of each of the washer housing depressions  162  and  163 . The pin  34  is tightly inserted into the pinhole  166  and a substantial length of the pin  34  extends between the two extending portions  16 .  
      The base seat  20  includes a fixing board  22  and two sideboards  24 . The fixing board  22  defines a plurality of threaded assembling holes  222 . In this embodiment, there are four assembling holes  222 . The base seat  20  is mounted to the display unit  100  by means of the assembling holes  222 . Two opposite edges of the fixing board  22  each forms a sideboard  24  perpendicularly extending outwards. Each of the sideboards  24  defines an engaging hole  242 . The engaging holes  242  are deformed, i.e., are non-circular holes. In this embodiment, the engaging holes  242  are “D” shaped.  
      The pivotal shaft  31  is substantially cylindrical in shape. The pivotal shaft  31  includes a bolt cap  312  and a bolt shaft  316 . The bolt cap  312  is substantially a disk-like shape. The bolt shaft  316  defines a thread  318  on a distal end portion thereof opposite to the bolt cap  312 . The bolt shaft  316  is flattened along a line parallel to an axis of the bolt shaft  316  of the curved surface area forming a flat surface  314  resulting the thread  318  thereof non-continuous and the section of the bolt shaft  316  corresponds to the shape and size of the engaging hole  242  of the base seat  20 . The bolt shaft  316  passes through one engaging hole  242  of the base seat  20  and one pivoting hole  160  of the support seat  10  correspondingly.  
      The irregular-holed tab washers  41  is approximately ring-shaped. Two opposite first tabs  412  are formed at a periphery of each irregular-holed tab washer  41 . The irregular-holed tab washer  41  defines an irregular hole  414  in the center thereof. The first tabs  412  of the irregular-holed tab washer  41  are configured to engage in the receiving slot  162  of the extending portion  16  of the support seat  10 . A limiting protrusion  416  extends inwards on an arc of the irregular hole  414 . The limiting protrusion  416  has two symmetrical edges  417  and  418  and is substantially □-shaped (i.e., a rotated wide-angle V shape). An angle defined by the edges  417  and  418  establishes the rotational angle limits for the two pivot mechanisms  30  of hinge assembly  300  and, thus, for the display unit  100  relative to the support body  200 . One such limiting protrusion  416  is readily manufactured. A precision of rotation range is easily controlled.  
      The tab washers  42  are approximately ring-shaped. Two opposite tabs  422  are formed at a periphery of each tab washer  42 . The second tabs  422  of the tab washer  42  are configured to engage in the receiving slot  163  of the extending portion  16  of the support seat  10 .  
      The D-hole washers  51  and  52  are approximately ring-shaped. The washers  51  and  52  define a first latching hole  512  and a second latching hole  522  respectively. The first and second latching holes  512  and  522  are both deformed, i.e., are non-circular holes. In this embodiment, the first and second latching holes  512  and  522  are “D” shaped. That is, the first and second latching holes  512  and  522  have a corresponding shape and size to the engaging hole  242  of the base seat  20 .  
      The spring washers  61  and  62  are disked-shaped. The two spring washers are configured to provide an axial force. An amount of friction that helps the display unit  100  retaining any desired position relative to the support body  200  is generated between the elements of the pivot mechanisms.  
      The resilient element  70  is a helical torsion spring having a first latching end  702  and a second latching end  704 . The first latching end  702  extends along a radial direction of the resilient element  70  and the second latching end  704  extends along an axial direction. When the hinge assembly  300  is assembled, the resilient element  70  exerts a predetermined torsion force. A diameter of the resilient element  80  is larger than that of the irregular-holed tab washer  41 , the tab washer  42 , the D-hole washers  51  and  52 , and the spring washers  61  and  62 .  
      The limiting washer  80  is approximately ring-shaped. The limiting washer  80  defines a third latching hole  802 . The third latching hole  802  is deformed, i.e., are non-circular holes. In this embodiment, the third latching hole  802  is “D” shaped. That is, the third latching hole  802  has a corresponding shape and size of the engaging hole  242  of the base seat  20 . The limiting washer  80  forms a limiting block  804  at its periphery. The limiting block  804  approximately extends along an involute of the limiting washer  80 .  
      The screw nut  90  defines a thread  902  therein to be fastened with the thread  318  of the bolt shaft  316  of the pivotal shaft  31 .  
      During assembly, referring now to  FIGS. 3-5 , the irregular-holed tab washers  41  are disposed in the washer housing depressions  162  and the tab washers  42  are disposed in the washer housing depressions  163  of support seat  10 . The first and second tabs  412  and  422  of the irregular-holed tab washers  41  and tab washers  42  are fixed in the receiving slots  164  so as to make the irregular-holed tab washers  41  and tab washers  42  be non-rotatable relative to the extending portion  16  of the support seat  10 . The pins  34  are securedly attached to the support seat  10 . One resilient element  70  is placed around the bolt shaft  316  of one pivotal shaft  31  correspondingly. The resilient element  70  has a predetermined torque force. The bolt shaft  316  of the pivotal shaft  31  passes through the engaging hole  242  of one sideboard  24  of the base seat  20 , the irregular hole  414  of one irregular-holed tab washer  41 , the pivoting hole  160  of one extending portion  16  of the support seat  10 , one tab washer  42 , one D-hole washer  51 , two spring washers  61  and  62 , one D-hole washer  52 , and one limiting washer  80 , in that order. The spring washers  51  and  52  are disposed adjacent each other facing opposite directions. The first latching end  702  of the resilient element  70  pushes the pin  34 , and the second latching end  704  of the resilient element  70  pushes the limiting block  804  of the limiting washer  80 . The screw nut  90  is screwed via the thread  318  on the pivotal shaft  31 . The screw nut  90  is adjoining the limiting washer  80 . Thereby, a pivot mechanism  30  is formed. Another pivot mechanism  30  is formed in similar manners.  
      After assembling, the irregular-holed tab washers  41  and the tab washers  42  are non-rotatable relative to the support seat  10 . The D-hole washers  51  and  52 , the limiting washers  80 , the pivotal shafts  31 , and the screw nuts  90  are non-rotatable relative to the base seat  20 . The irregular-holed tab washer  41 , the tab washer  42 , the D-hole washers  51  and  52 , the spring washers  61  and  62 , and the limiting washer  80 , collaboratively maintain the desired spacing between the various portions of the pivot mechanism of the hinge assembly  300 . Furthermore, the irregular-holed tab washer  41 , the tab washer  42 , the D-hole washers  51  and  52 , the spring washers  61  and  62 , and the limiting washer  80  collaboratively produce an amount of friction that allows movement of the display unit  100  relative to the support body  200  upon application of a moderate external force but that, otherwise, helps retain the desired positioning between the support body  200  and the display unit  100 . Part of the needed friction can, be expected to be gained through the operation of the other elements of the hinge assembly  300 , as well.  
      In use, a pushing force is exerted on the display unit  100 , and, in turn, the display unit  100  causes the base seat  20  to likewise move. The D-hole washers  51  and  52 , the limiting washers  80  and the pivotal shafts  31  also rotate with the base seat  20 . Accordingly, the second latching ends  704  of the resilient elements  70  that push the limiting blocks  804  of the limiting washers  80  rotate, whereby increasing or decreasing the torsion force of the resilient elements  70 . Suppose that the display unit  100  is in a middle position, the torsion force of the resilient elements  70  increases when the display unit  100  rotates toward a first direction and the torsion force decreases when the display unit  100  rotates toward an opposite second direction. The support seat  10  is fixed relative to the support body  200 . When the display unit  100  rotates through a determined angle toward the first direction, the edge  417  pushes the flat surface  314  to prevent the base seat  20  rotating further. When the display unit  100  rotates through a determined angle toward the second direction, the edge  418  pushes the flat surface  314  so as to prevent the base seat  20  rotating further. Thereby, the display unit  100  together with the base seat  20  cannot rotate further accordingly. The irregular-holed tab washers  41  and the tab washers  42  disposed between the support seat  10  and the base seat  20  may decrease the abrasion between the support seat  10  and the base seat  20  so as to prolong the use life.  
      In alternative embodiments, the pivotal shaft  31  is fastened, e.g., by means of other holding members such as a rivet or by a ring. In this manner, a C-shaped ring and a receiving groove for example, replace the screw nut  90  and the thread  318  of the bolt shaft  316 . Only single pivot mechanism  30  may be provided. Accordingly, the extending portion  16  of the support seat  10 , the sideboard  24  of the base seat  20  and the pin  34  may also exist singularly. Other flat washers with non-circular hole may replace the D-hole washers  51  and  52 . Other resilient members such as springs and other elastic washers may replace the spring washers  61 ,  62 . The support seat  10  may be mounted to the display unit  100 , and accordingly the base seat  20  may be mounted to the support body  200 .  
      As described above, the preferred embodiments provides a hinge assembly  300  for devices such as a flat display screen, which is convenient for a user to operate and which is durable. It is, however, to be understood that the hinge assembly  300  could potentially be useful in other applications (e.g., a free-standing, adjustable mirror) in which it may be desirable to allow selective pivoting over a limited angular range.  
      It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.