A hinge assembly (10) includes a shaft (20), a follower (22), a cam (30), a washer (50), a rolling 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 rolling 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.