1. Field of the Invention
The present invention relates to a cam interference assembly of a hinge, and a foldable device using the cam interference assembly.
2. Description of Related Art
A foldable device, such as a notebook computer and a clamshell mobile phone, generally includes a base and a cover pivotally mounted to the base with a hinge. The hinge generally includes a first element and a second element for positioning the cover during rotation. The first element includes two raised portions and the second element includes two depressed portions for receiving the raised portions. When the cover is rotated, the first element is rotated relative to the second element, the raised portions are moved out from the corresponding depressed portions, resulting in friction between the first and second elements, thereby causing the first and second elements to wear out.
What is needed, therefore, is a hinge having a cam interference assembly which can provide balanced rotation of the hinge.
Referring to
The first element 10 is generally cylinder-shaped. The first element 10 defines a round through hole 12 in a central portion of the first element 10. The through hole 12 extends through a first mating surface 11 and out an opposite exposed surface, configured for receiving a non-cylindrical shaft (not shown). The first mating surface 11 defines an arc-shaped first depressed portion 16 and an arc-shaped second depressed portion 18 opposite to the first depressed portion 16. Each end of the first depressed portion 16 includes a slanting connecting surface 162 connecting a bottom of the first depressed portion 16 to the first mating surface 11. Each ends of the second depressed portion 18 includes a slanting connecting surface 182 connecting a bottom of the second depressed portion 18 to the first mating surface 11. A depth of the bottom of the first and second depressed portions 16, 18 from the first mating surface 11 may be substantially equal. In the illustrated embodiment, the first depressed portion 16 is adjacent to the through hole 12, and the second depressed portion 18 is adjacent to an edge of the first element 10 away from the through hole 12. In one embodiment, the depressed portions 16, 18 may both be adjacent to the through hole 12. In another embodiment, the depressed portions 16, 18 may both be adjacent to the edge of the first element 10 away from the through hole 12. The first mating surface 11 defines a plurality of recessed cavities 19 capable of retaining oil. A protrusion (not labeled) extends outwardly from a sidewall of the first element 10. A fastening post 14 extends from a distal end of the protrusion away from the first mating surface 11, and extends along an axial direction of the first element 10 configured for fixing the first element 10 to the foldable device 50.
The second element 20 is generally cylinder-shaped. A central portion of the second element 20 defines a non-circular fixing hole 22 having a substantially similar size and shape to the size and shape of the shaft, such that the shaft cannot rotate along a central axis of the shaft. A second mating surface 21 of the second element 20 faces the first mating surface 11. An arc-shaped first raised portion 26 protrudes from the second mating surface 21 and configured for engaging with the first depressed portion 16. Each end of the first raised portion 26 includes a slanting connecting surface 262 connecting a top of the first raised portion 26 and the second mating surface 21. An arc-shaped second raised portion 28 protrudes from the second mating surface 21 opposite to the first raised portion 26, and configured for engaging with the second depressed portion 18 of the first element 10. Each end of the second raised portion 28 includes a slanting connecting surface 282 connecting a top of the second raised portion 28 to the second mating surface 21. A height of the first and second raised portions 26, 28 may be substantially equal to the depth of the first and second depressed portions 16, 18. Depending on the embodiment, the first raised portion 26 and the second raised portion 28 are positioned so that when the first element 10 is mated to the second element 20, the first raised portion 26 is received in the first depressed portion 16, and the second raised portion 28 is received in the second depressed portion 18. The second mating surface 21 defines a plurality of recessed portions 24 capable of retaining oil.
Referring also to
Referring also
When closing the cover 52, the cover 52 is moved toward the base 54. As the closing movement continues, the first raised portion 16 slides along one of the connecting surfaces 162 to enter into the first depressed portion 16 and the second raised portion 28 slides along one of the connecting surfaces 182 to enter into the second depressed portion 18. At this moment, the cover 52 may be physically released because the cover 52 will continue to rotate by force of inertia, but lightly so as not to bump hard against the base 54. When the first and second raised portions 26, 28 are respectively engaged in the first and second depressed portions 16, 18, the cover 52 is closed to the base 54.
It is believed that the present embodiment and its 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 example hereinbefore described merely being preferred or exemplary embodiments.
Number | Date | Country | Kind |
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200820301286.7 | Jun 2008 | CN | national |