Apparatus for changing positions of seat for vehicles

An apparatus for changing positions of a seat for vehicles, the apparatus comprising:

• a movable rail coupled to a stationary rail to be movable forwards and rearwards;
• a rear support frame mounted on the movable rail by a hinge shaft to be rotatable upwards and downwards;
• a middle support frame connected integrally to a front end of the rear support frame at a designated angle;
• a front support frame provided with a lower end connected integrally to a front end of the middle support frame, and an upper end hinge-coupled to a seat cushion frame;
• a connection frame formed integrally with a rear end of the rear support frame and disposed in a width direction;
• a motor mounted under the rear support frame and connected to the hinge shaft to transmit rotating power thereto;
• and
• an electric cylinder configured to connect the connection frame and a seat back frame to each other using hinges to be movable upwards and downwards.