Patent Publication Number: US-2007094845-A1

Title: [hinge]

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to hinges and more particularly, to a durable hinge, which has means to release the torque from the friction spring washers during the operation, preventing damage to the friction spring washers.  
      2. Description of the Related Art  
      In a vehicle rearview mirror, notebook computer, electronic dictionary, PDA, or any of a variety of two-leaf type electronic devices, a hinge is used to let two parts be turnable relative to each other and then quickly positioned in the desired position.  
      A conventional hinge is known comprising a pivot shaft and a set of washers. The pivot shaft uses the torque between the rotor and the stator to overcome the gravity weight of the supported member, for example, the cover of a notebook computer. The torque must be properly controlled. An excessively high torque causes the user unable to turn the supported part smoothly. An excessively low torque causes the pivot shaft unable to support the supported member in position. This torque has a great concern with the fabrication precision as well as the structural design of the hinge.  
      A hinge design is disclosed. According to this design, as shown in  FIG. 8 , the hinge comprises a first mounting member D, a second mounting member C, a pivot shaft A, which has a first end pivotally coupled to the first mounting member D and a second end longitudinally ribbed and coupled to the longitudinally grooved coupling hole (not shown) at the second mounting member C, and a washer set B mounted on the pivot shaft A and firmly positioned in the first mounting member D. Each washer B 1  has a center axle hole B 2  for the passing of the pivot shaft A, a slot B 4 , a passage B 3  in communication between the slot B 4  and the center axle hole B 2 , two friction arms B 5  bilaterally suspending between the slot B 4  and the center axle hole B 2 , and an inside notch B 6  in communication with the center axle hole B 2  at one side opposite to the passage B 3 . The slot B 4 , the passage B 3 , the axle hole B 2  and the inside notch B 6  form a lubricating oil space for receiving a lubricating oil to prevent breaking of the washers B 1  during rotary motion of the pivot shaft A relative to the washers B 1  and the first mounting member D.  
      This design of hinge is still not satisfactory in function because of the following drawbacks.  
      1. The torque produced during rotary motion of the pivot shaft A is distributed radially outwards through the washers Bi, at this time, the lower part of each washer B 1  receives a great portion of the torque, therefore the lower part of each washer B 1  may break easily.  
      2. Each washer B 1  has an inside notch B 6  for receiving the lubricating oil. Actually, this inside notch B 6  is not necessary. When the pivot shaft A is turning upwards, a gap will be produced between the bottom side of the pivot shaft A and each washer B 1  in the center axle hole B 2  of each washer B 1  for receiving the lubricating oil. An excessive mount of the lubricating oil may be accumulated in the inside notch B 6  and the lower part of the center axle hole B 2  of each washer B 1 , causing the pivot shaft A to displace from the expected position.  
      3. Further, because the second end of the pivot shaft A is longitudinally ribbed and coupled to the longitudinally grooved coupling hole at the second mounting member C, the second mounting member C may be forced away from the second end of the pivot shaft A accidentally.  
      Therefore, it is desired to provide a hinge that eliminates the aforesaid drawbacks.  
     SUMMARY OF THE INVENTION  
      The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide to a hinge, which is durable in use. To achieve this and other objects of the present invention, the hinge comprises a first housing member, a mounting member, a pivot shaft, which has a first connecting portion pivotally coupled to the housing member and a second connecting portion affixed to the mounting member, and a friction spring washer set mounted on the pivot shaft and secured to the housing member, wherein each friction spring washer has a peripheral deformable portion and a peripheral notch in the peripheral deformable portion for releasing torque produced against the friction spring washers during rotary motion of the pivot shaft with the mounting member relative to the housing member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an elevational assembly view of a hinge according to the present invention.  
       FIG. 2  is an exploded view of the hinge according to the present invention.  
       FIG. 3  is an exploded view of a part of the hinge according to the present invention.  
       FIG. 4  is a front plain view of the present invention before rotary motion of the pivot shaft.  
       FIG. 5  is similar to  FIG. 4  but showing the pivot shaft rotated.  
       FIG. 6  is an exploded view of an alternate form of the hinge according to the present invention.  
       FIG. 7  is an elevational view in an enlarged scale of one friction spring washer of the friction spring washer set shown in  FIG. 6 .  
       FIG. 8  is an exploded view of a hinge according to the prior art. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring to FIGS.  1 ˜ 3 , a hinge in accordance with the present invention is shown comprised of a pivot shaft  1 , a friction spring washer set  2 , a housing member  3 , and a mounting member  4 .  
      The pivot shaft  1  has a first connecting portion  11  and a second connecting portion  12  respectively disposed at the two distal ends thereof. The second connecting portion  12  has two longitudinal cut planes  121  arranged in parallel at two opposite sides, and a locating groove  122  extending around the periphery across the cut planes  121 .  
      The friction spring washer set  2  is comprised of a set of identical friction spring washers  21 . The contour of the friction spring washers  21  shows a substantially circular shape. Each friction spring washer  21  has a center axle hole  210  for accommodating lubricating oil and for the passing of the pivot shaft  1 , a smoothly arched slot  211  spaced around the center axle hole  210  for accommodating lubricating oil and having a middle part in communication with the center axle hole  210 , two friction arms  212  bilaterally suspending between the smoothly arched slot  211  and the center axle hole  210 , a deformable portion  22  formed of a part of the border area remote from the smoothly arched slot  211 , a peripheral notch  221  formed in the deformable portion  22 , and two shoulders  213  bilaterally spaced between the smoothly arched slot  211  and the deformable portion  22 .  
      The housing member  3  has a barrel  31  disposed at one side. The barrel  31  defines a receiving chamber  30 .  
      The mounting member  4  comprises a socket  40  disposed at one side for receiving the second connecting portion  12  of the pivot shaft  1 , two locating flanges  401  symmetrically disposed at two opposite sides inside the socket  40 , an inside locating rib  402  disposed inside the socket  40  and adapted to engage the locating groove  122 , a radial through hole  403  radially cut through the peripheral wall of the socket  40 , and a locating pin  4031  inserted into the radial through hole  403 .  
      The assembly process of the present invention is simple and outlined hereinafter with reference to  FIGS. 4 and 5  and  FIG. 2  again. The pivot shaft  1  is inserted through the center axle hole  210  of each of the friction spring washers  21  to have the first connecting portion  11  be exposed to the outside of the friction spring washer set  2 , and then the first connecting portion  11  of the pivot shaft  1  is inserted with the friction spring washer set  2  into the inside of the receiving chamber  30  of the barrel  31  of the housing member  3 , and then the first connecting portion  11  of the pivot shaft  1  is pivotally coupled to a part of the inside of the receiving chamber  30  of the barrel  31  of the housing member  3 , and then the second connecting portion  12  of the pivot shaft  1  is inserted into the socket  40  to attach the two cut planes  121  to the locating flanges  401  to further prohibit rotation of the pivot shaft  1  relative to the mounting member  4  and simultaneously to force the locating groove  122  into engagement with the locating rib  402  in the socket  40 , and then the locating pin  4031  which is mounted in the radial through hole  403  is forced into the locating groove  122  to stop axial movement of the pivot shaft  1  relative to the mounting member  4 . When the hinge is assembled, lubricating oil is filled into the smoothly arched slot  211  of each of the friction spring washers  21 , and then rotate the mounting member  4  and the pivot shaft  1  relative to the housing member  3  to let lubricating oil flow downward from the smoothly arched slot  211  of each friction spring washer  21  to the bottom side of the center axle hole  210  of each friction spring washer  21  to lubricate the whole friction spring washer set  2  so as to reduce torque between the mounting member  4  and the friction spring washer set  2  when rotating the mounting member  4  and the pivot shaft  1  relative to the housing member  3 .  
      During rotary motion of the pivot shaft  1  relative to the housing member  3 , a torque is produced against the friction spring washer set  2 . At this time, the deformable portion  22  of each friction spring washer  21  is deformed to release the torque through the peripheral notch  221  of each friction spring washer  21 , preventing breaking of the friction spring washers  21 .  
      Further, then amount of the friction spring washers  21  of the friction spring washer set  2  is determined subject to the desired torque, i.e., the amount of the friction spring washers  21  is relatively increased when a relatively higher torque is required, and the amount of the friction spring washers  21  is relatively reduced when a relatively lower torque is required.  
      Further, the aforesaid deformation portion  22  of each friction spring washer  21  and the peripheral notch  221  in the deformation portion  22  are designed to release the torque produced upon rotary motion of the shaft  1 , they can be made in any shape and form capable of releasing the torque produced against the friction spring washer set  2  during rotary motion the pivot shaft  1  with the mounting member  4 .  
       FIGS. 6 and 7  show an alternate form of the hinge according to the present invention. Each friction spring washer  21  of the friction spring washer set  2  according to this second embodiment is substantially similar to the aforesaid first embodiment with the exception that the deformable portion  22  defines two extensions  222  separated by the peripheral notch  221 . When the friction spring washers  21  are twisted upon rotation of the pivot shaft  1 , the peripheral notch  221  and the two extensions  222  allow the deformable portion  22  of the respective friction spring washer  21  to be temporarily deformed through at a relatively greater extent against the twisting force from the pivot shaft  1 , preventing breaking of the friction spring washers  21  and extending the service life of the friction spring washers  21 .  
      As indicated above, the hinge of the present invention has the following characteristics.  
      1. The torque produced during rotary motion of the pivot shaft  1  is distributed spirally outwards through the inner diameter each friction spring washer  21  toward the border area of each friction spring washer  21  and the bottom side of each friction spring washer  21 , and the deformable portion  22  of each friction spring washer  21  is deformed to release the torque through the peripheral notch  221  of each friction spring washer  21 , and therefore the friction spring washers  21  do not break and are durable in use.  
      2. When the friction spring washers  21  are squeezed by the torque produced during rotary motion of the pivot shaft  1 , lubricating oil is forced to permeate downwards from the smoothly arched slot  211  of each friction spring washer  21  into the gap in the bottom side of the center axle hole  210  between the pivot shaft  1  and each friction spring washer  21 , and therefore the friction spring washers  21  are constantly well lubricated.  
      3. The engagement between the locating flanges  401  and the cut planes  121  prevent rotary motion of the pivot shaft  1  relative to the mounting member  4 ; the engagement between the locating rib  402  and the locating groove  122  and the engagement between the locating pin  4031  and the locating groove  122  prevent axial movement of the pivot shaft  1  relative to the mounting member  4 .  
      Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention.