Thin pivotal apparatus

A thin pivotal apparatus, comprising:

• a holding seat including a base, a housing space formed on the base and a first assembly portion and a second assembly portion located on the base and corresponding to two opposite sides of the housing space;
• an arc-shaped driven member which is located in the housing space and includes an operational portion, a curved portion connected to the operational portion and a driving portion extended from the curved portion toward the operational portion and connected to the first assembly portion to form a pivotal relationship;
• and
• at least one torsional force generation member including a first connection portion pivotally installed on the second assembly portion, a second connection portion pivotally connected to the junction of the driving portion and the curved portion, and a hydraulic portion connected between the first connection portion and the second connection portion and driven by the driving portion to move synchronously to generate a corresponding swivel torsional force.