Abstract:
A hinge is mounted between a cover and a body of an electronic device and has an eccentric sleeve and a resisting assembly abutting against each other. When the cover is pivoted, the eccentric sleeve is rotated as well. Because the eccentric sleeve has sectors with varied radiuses, the resisting assembly is compressed to conduct various resisting forces when the eccentric sleeve is rotated. When the cover is opened to a normal visual angle, the hinge provides a constant largest torque. Therefore, the cover is held at the normal visual angle even though the user hits the touch panel on the cover.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hinge and, especially, to a hinge mounted between a cover and a body of an electronic device to allow the cover to pivot relative to the body. 
     2. Description of the Prior Arts 
     The conventional hinge is mounted between a cover and a body of an electronic device. Conventional hinges have disclosed various structures to provide torque variation so that the force exerted by users to open the cover varies accordingly, and that does help users to easily open/close the cover. Also, said conventional structure has to provide a positioning function in a manner such that the cover of the electronic device can be kept at certain visual angle. In general, in order to achieve the above function, there are two kinds of the hinge structures: (1) a structure with a resilient sleeve embracing a pintle, both having corresponding flat surfaces to be selectively engaged with each other, during the rotation of the pintle, as the positioning function, and (2) a structure with a stationary positioning washer (called a cam) non-rotatably mounted on a pintle and a rotating positioning washer rotatably mounted on the pintle, each having corresponding protrusions and detents to be engaged to generate the torque variation and positioning function. 
     With reference to  FIG. 11 , the torque provided by the conventional hinge with the resilient sleeve and the pintle both having corresponding flat surfaces changes with the rotating angle of the cover relative to the body. Suppose that the torque is positive when the cover is opening and that the torque is negative when the cover is closing. At the very beginning, the cover is closed relative the body, and the flat surface of the resilient sleeve faces and engages with flat surface of the pintle so that the conventional hinge provides a largest torque when the cover starts to be pivoted to open. Once the cover is pivoted over 12 degrees, the flat surfaces of the resilient sleeve and the pintle are separated. Then, the torque is decreased until the cover is pivoted at about 35 degrees. When the cover is pivoted over 35 degrees, the conventional hinge provides a constant torque. When the cover is being closed and the included angle between the cover and the body is less than 10 degrees, the corresponding flat surfaces engage with each other so that the torque decreases rapidly to urge the cover closing quickly. Therefore, the user needs to provide a certain force to open the cover. Further, the cover quickly closing causes the latching between the cover and the body to be firm. Another conventional hinge with positioning washers having corresponding protrusions and detents also has a similar torque variation as shown in  FIG. 11 . 
     Generally, when the cover is pivoted over 35 degrees, both conventional hinges are capable of holding the cover with its weight at a certain visual angle even though the torque is less than the largest torque. However, with the popularity of the electronic device and the development of the touch panel, the touch panel is widely mounted in the cover to replace the traditional display panel. When the user acts on the touch panel, the cover bears extra force besides its own weight. The conventional hinges do not provide enough torque to hold the cover with extra force. Thus, the conventional hinge is not suitable for the cover with a touch panel. 
     SUMMARY OF THE INVENTION 
     The main objective of the present invention is to provide a hinge to hold the cover of the electronic device when subjected to extra force. The hinge is mounted between the cover and the body of the electronic device and has an eccentric sleeve and a resisting assembly abutting against each other. When the cover is pivoted, the eccentric sleeve is rotated as well. Because the eccentric sleeve has sectors with varied radius, the resisting assembly is compressed to conduct various resisting forces when the eccentric sleeve is rotated. When the cover is opened to a normal visual angle, the hinge provides a constant largest torque. Therefore, the cover is held at the normal visual angle even though the user hits the touch panel on the cover. 
     Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a hinge in accordance with the present invention; 
         FIG. 2  is an exploded perspective view of the hinge in  FIG. 1 ; 
         FIG. 3  is another exploded perspective view of the hinge in  FIG. 1 ; 
         FIG. 4  is an end view of an eccentric sleeve of the hinge in  FIG. 1 ; 
         FIG. 5  is a graph depicting a number of a rotating angle plotted against torque of the hinge in  FIG. 1 ; 
         FIG. 6  is an operational side view in partial section of the hinge in  FIG. 1 , shown with the cover at 0 degree; 
         FIG. 7  is an operational side view in partial section of the hinge in  FIG. 1 , shown with the cover between 35 to 90 degrees; 
         FIG. 8  is an operational side view in partial section of the hinge in  FIG. 1 , shown with the cover at 90 degrees; 
         FIG. 9  is an operational side view in partial section of the hinge in  FIG. 1 , shown with the cover over 90 degrees; 
         FIG. 11  is a graph depicting a number of a rotating angle plotted against torque of a conventional hinge. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 and 2 , a hinge in accordance with the present invention comprises a stationary frame  10 , a resisting assembly  20 , an eccentric sleeve  30 , a pintle  40  and a torque generating assembly. 
     With reference to  FIGS. 2 and 3 , the stationary frame  10  has a first sidewall  11 , a second sidewall  12  and an end wall  13 . The end wall  13  is formed across the first sidewall  11  and the second sidewall  12 . The first sidewall  11  has a keyed hole  111  formed therethrough. The second sidewall  12  has a through hole  121  formed therethrough and aligning with the keyed hole  111  of the first sidewall  11 . The end wall  13  has at least one post  131  formed on an inner surface of the end wall  13 . 
     The resisting assembly  20  is mounted in the stationary frame  10 , is mounted between the first sidewall  11  and the second sidewall  12  and has a slide  22  and at least one resilient element  21 . The slide  22  is mounted slidably between the first sidewall  11  and the second sidewall  12  of the stationary frame  10  and has a rib  221  formed on an outer surface of the slide  22 . The resilient element  21  is clamped between an inner surface of the slide  22  and the end wall  13  of the stationary frame  10 . Each resilient element  21  may be a spring and may be mounted around the post  131  on the end wall  13 . 
     The eccentric sleeve  30  is mounted in the stationary frame  10 , is mounted across the first sidewall  11  and the second sidewall  12  and has an axial hole  31 , an initial sector  32 , a lifting sector  33  and a steady sector  34 . The axial hole  31  aligns with the keyed hole  111  and the through hole  121 . The initial sector  32 , the lifting sector  33  and the steady sector  34  are defined in sequence on the eccentric sleeve  30  and selectively abut the rib  221  of the slide  22 . The lifting sector  33  has a first end  331  and a second end  332 . The first end  331  is connected to the initial sector  32 . The second end  332  is connected to the steady sector  34 . The initial sector  32  has a radius that is a distance from a center  311  of the axial hole  31  to a periphery edge of the initial sector  32 . The lifting sector  33  has a radius that is a distance from a center  311  of the axial hole  31  to a periphery edge of the lifting sector  33 . The steady sector  34  has a radius that is a distance from a center  311  of the axial hole  31  to a periphery edge of the steady sector  34 . The radius of the initial sector  32  is constant. The radius of the lifting sector  33  is gradually increased. The radius of the steady sector  34  is constant. The radius of the initial sector  32  is smaller than the radius of the steady sector  34 . The first end  331  of the lifting sector  33  has a radius the same as the radius of the initial sector. The second end  332  of the lifting sector  33  has a radius the same as the radius of the steady sector  34 . 
     The included angle of the initial sector  32  is at least 35 degrees, the included angle of the lifting sector  33  is at least 55 degrees, and the included angle of the steady sector  34  is at least 35 degrees. In a preferred embodiment, the included angle of the initial sector  32  is 125 degrees for corresponding to the rib  221  of the slide  22 , the included angle of the lifting sector  33  is 55 degrees, and the included angle of the steady sector  34  is 180 degrees to provide constant torque. 
     With reference to  FIGS. 2 and 3 , the pintle  40  is mounted rotatably through the eccentric sleeve  30  and is attached securely to the stationary frame  10 . In a preferred embodiment, the pintle  40  is mounted in sequence through the through hole  121  of the second sidewall  12  of the stationary frame  10  and the axial hole  31  of the eccentric sleeve  30 . The pintle  40  has a keyed protrusion  41  formed on an end and engaging the keyed hole  111  of the first sidewall  11  of the stationary frame  10 . The pintle  40  has a flat surface  42  formed on an outside wall thereof. 
     The torque generating assembly may be a resilient sleeve  50  mounted rotatably around the pintle  40  and is connected securely to the eccentric sleeve  30 . The resilient sleeve  50  has a flat surface  51  formed on an inside wall thereof and selectively flush with the flat surface  42  of the pintle  40  to provide a positioning function. 
     Various structures are used to secure the eccentric sleeve  30  and the resilient sleeve  50 . In a preferred embodiment, the hinge further comprises a connecting sleeve  60  and a connecting bracket  70  to secure the eccentric sleeve  30  and the resilient sleeve  50 . The connecting sleeve  60  is mounted through the through hole  121  of the second sidewall  12  of the stationary frame  10  and has two protrusions  61  formed separately on an end thereof. The eccentric sleeve  30  has two protrusions  35  formed separately on an end thereof. The protrusions  61  of the connecting sleeve  60  respectively engage between the protrusions  35  of the eccentric sleeve  30  to hold the connecting sleeve  60  with the eccentric sleeve  30 . The connecting bracket  70  is mounted securely around the connecting sleeve  60 . The resilient sleeve  50  has a fastening wing  52  extending from an edge thereof. The connecting bracket  70  is attached securely to the fastening wing  52  of the resilient sleeve  50 . The resilient sleeve  50  may have an extending wing  521  formed perpendicularly on an end of the fastening wing  52 . 
     The stationary frame  10  further has a stop  122  formed on an outside surface of the second sidewall  12 . The connecting sleeve  60  has an arc limit  62  formed on an outside wall thereof and selectively abutting the stop  122  of the stationary frame  10  to limit the rotating angle of the eccentric sleeve  30  and the resilient sleeve  50 . 
     With reference to  FIG. 10 , an electronic device in accordance with the present invention comprises a cover  81 , a body  82  and at least one hinge as described. The hinge is mounted between the cover  81  and the body  82 . The pintle  40  is attached securely to the cover  81 . In a preferred embodiment, the extending wing  521  is flushly securely with the cover  81 . The stationary frame  10  is attached securely to the body  82 . When the cover  81  is pivoted relative to the body  82 , the resilient sleeve  50  and the eccentric sleeve  30  are rotated relative to the stationary frame  10  and the resisting assembly  20 . 
     With reference to  FIG. 4 , the eccentric sleeve  30  is rotated to various angles and the according torque is shown in  FIG. 5 . 
     With further reference to  FIG. 6 , the cover  81  is closed at 0 degree and is flush with the body  82 . The rib  221  of the slide  22  abuts the initial sector  32  of the eccentric sleeve  30 . The flat surface  51  of the resilient sleeve  50  is flush with the flat surface  42  of the pintle  40  to provide a positioning function. When the cover  81  is opening, the positioning function provides a larger torque. After the flat surface  51  of the resilient sleeve  50  disengages with the flat surface of the pintle  40 , the torque provided by hinge as described is decreased. 
     With further reference to  FIG. 7 , the cover  81  is pivoted over 35 degrees. The eccentric sleeve  30  is rotated, and, then, the lifting sector  33  abuts the rib  221  of the slide  22 . Since the lifting sector  33  has the gradually increasing radius, the slide  22  is pushed inward when the cover  81  is pivoting. Therefore, the slide  22  presses the resilient elements  21 . The pressed resilient elements  21  provide an extra resisting force so that the hinge as described provides an increasing torque when the cover  81  is pivoted over 35 degrees. 
     With further reference to  FIG. 8 , the cover  81  is opened at 90 degrees. The eccentric sleeve  30  is rotated and the second end  332  of the lifting sector  33  abuts the rib  221  of the slide  22 . The radius of the second end  332  of the lifting sector  33  has the largest radius so that the resilient elements  21  have the maximum compression. Therefore, the hinge as described provides the largest torque. 
     With further reference to  FIG. 9 , the cover  81  is opened over 90 degrees. The eccentric sleeve  30  is rotated, and the steady sector  34  abuts the rib  221  of the slide  22 . Since the radius of the steady sector  34  is the same as the second end  332  of the lifting sector  33  and is constant, the compression of the resilient elements  21  is constant so that the resistance of the resilient elements  21  is also constant. Therefore, the hinge as described provides the constant largest torque when the cover  81  is opened over 90 degrees. Because the cover  81  has a normal visual angle at 90 to 125 degrees, the constant largest torque holds the cover  81  firmly. Thus, even though the user may hit on the touch panel on the cover  81 , the hinge as described has the ability to hold the cover  81 . 
       FIG. 5  shows the torque variation. Before the cover  81  is opened to 35 degrees, the torque is mainly provided by the interaction of the flat surfaces of the resilient sleeve  50  and the pintle  40 . When the cover  81  is opened over 35 degrees, the resisting assembly  20  provides extra torque. The person skilled in the art could change the torque generating assembly to other structures, such as positioning washers, without influencing the torque provided by the resisting assembly  20 . 
     Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts, within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.