Hinge

#1. Field of the Invention

#The present invention relates to a hinge, and more particularly to a hinge for smoothly opening or closing a foldable electronic device.

#2. The Related Art

#The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the attached drawings, in which:

#FIG. 1 is an exploded view of a prior hinge;

#FIG. 2 is a perspective view of a hinge of the present invention which is cut partially for distinctly showing the structure thereof;

#Referring to FIG. 2 and FIG. 3, a hinge in accordance with the present invention includes a housing 3 which is hollow. Both ends of the housing 3 communicate with the outside. A stopper 2 is plugged up one end of the housing 3, and the stopper 2 defines a through-hole 201 passing therethrough. A torsion-bar spring 4 and a sliding cam 5 are slideably received in the housing 3. One end of the spring 4 is fastened around the stopper 2 that protrudes into an inner of the housing 3, and an opposite end of the spring 4 is fixed on the sliding cam 5. A shaft 11 runs through the sliding cam 5, the spring 3 and the through-hole 201 of the stopper 2 in turn. One end of the shaft 11 defines a notch 112 around thereof and the notch 112 is exposed out of the stopper 2. A limiting ring 1 is provided to locate the end of the shaft 11 on the stopper 2. The limiting ring 1 is substantially E-shaped and defines a gap thereon. The limiting ring 1 is locked in the notch 112 of the shaft 11 and is closely adjacent to an outer surface of the stopper 2. The other end of the shaft 11 extends out of the sliding cam 5 and protrudes outward around thereof to form a protrusion portion 111. The protrusion portion 111 of the shaft 11 is assembled in a rotatable cam 6 which mates with the sliding cam 5. A damper 20 couples with the rotatable cam 6, and the damper 20 is accommodated in a cap 30. The sliding cam 5, the rotatable cam 6, the damper 20 and the cap 30 will be described in detail hereinafter.

#Please refer to FIG. 8. The sliding cam 5 has a cylindrical accepting portion 51 that defines two concave portions 53 on a top surface thereof. The two concave portions 53 are substantially V-shaped and defined opposite to each other. Each of the concave portions 53 has an ascending curved surface and a descendent curved surface which is relative to the ascending curved surface. The accepting portion 51 defines an axial hole 54 passing therethrough at center. A supporting portion 52 which is in hollow column shape extends downward from the inner surface of the axial hole 54 and is integrated with the accepting portion 51. The supporting portion 52 has the same axle center as the axial hole 54.

#Please refer to FIG. 7. The rotatable cam 6 has a substantially column-shaped base portion 61. The bottom of the base portion 61 projects downward to form a column-shaped rotatable pillar 67 at center. A radius of the rotatable pillar 67 is less than a radius of the base portion 61. A receiving hole 68 is defined in the center of the rotatable pillar 67. An end of the receiving hole 68 passes through the bottom of the rotatable pillar 67, but the other end of the receiving hole 68 is sealed. Two pushing portions 62 extend downward from the bottom of the base portion 61 and adjoin a peripheral wall of the rotatable pillar 67. The two pushing portions 62 are designed in substantial V-shape and distributed opposite to each other. A top surface of the base portion 61 protrudes upward and then defines a circular stepped portion, which has a lower portion 63 and an upper portion 64. The lower portion 63 and the upper portion 64 share a same axle center. A radius of the lower portion 63 is greater than a radius of the upper portion 64. A center cavity 66 is defined downward at the axle center of the upper portion 64. The inner surface of the center cavity 66 protrudes inward to form a shoulder 65 therein.