Abstract: A hinge assembly (10) includes a shaft (20), a follower (22), a cam (30), a washer (50), a lubrication mass forming means, and an urging means. The shaft has a securing portion (21) formed at one end thereof. The follower connects with the shaft. The cam essentially is in the shape of a cylinder, and includes a cam surface (32) and defines a cam hole (31) extending therethrough. The cam hole receives the shaft therethrough. The washer defines a center hole (52), and is located around the shaft. The lubrication mass forming means is disposed between the washer and the cam. One end of the urging means abuts the shaft, and an opposite end of the urging means biases the washer. The cam surface of the cam is rotatably and movably engaged with the follower under force of the urging means.

Abstract: A hinge assembly includes a shaft (10), a follower (12), a cam (20), at least one rolling member (40), and a spring (50). The follower is connected with the shaft. One of the shaft and the follower has a securing portion (11). The cam is essentially in the shape of a cylinder. The cam has a cam surface (24) and has a cam hole (22) extending therethrough. The cam hole receives the shaft there through. Each rolling member is disposed between the follower and the cam. The first end of the urging means abuts the shaft, while an opposite second end of the urging means biases the cam. The cam surface of the cam is rotatably and movably engaged with each rolling member under the force of the spring.

Abstract: A hinge assembly (10) includes a shaft (20), a follower (22), a cam (30), at least one oil storing receptacle (33), and an urging means (40). The shaft has a securing portion (21) formed at a first end thereof. The follower connects with the shaft. The cam is essentially in the shape of a cylinder, and includes a cam surface (32) and defines a cam hole (31) extending therethrough. The cam hole receives the shaft therethrough. In one embodiment, a first end of the urging means abuts an opposite second end of the shaft, and an opposite second end of the urging means biases the cam. Three oil storing receptacles are disposed generally between the cam and the urging means. The cam surface of the cam is rotatably and movably engaged with the follower under force of the urging means.

Abstract: A hinge mechanism includes a shaft (1), at least one cam follower (12), a cam (2), a washer (3) and an elastic member (4). Each cam follower has a projection (120) connected to the shaft. The cam has a cam surface (24) defined thereon. The shaft runs through the cam, the washer and the elastic member, in turn. The cam surface of the cam faces the projection of each cam follower, and the cam abuts the cam follower, due to the spring force generated by the elastic member. The washer and the cam are magnetic, the facing portions thereof having the same polarity. As a result of the repulsive magnetic force between the cam and washer, the hinge mechanism generates a smaller friction therebetween, so the waste of energy is very small. The present hinge mechanism can be used in foldable electronic devices.