Abstract: A ram driving method including the steps of fixing one end of a large-diameter piston rod integral with a large-diameter piston reciprocably included in a large-diameter cylinder attached integrally to a ram to a fixing unit, connecting one end of a small-diameter piston rod integral with a small-diameter piston reciprocably included in a small-diameter cylinder integral with the large-diameter cylinder to a moving member moved by a motor driving, integrally moving the small-diameter cylinder and the small-diameter piston and communicating a first compartment and a second compartment of the large-diameter cylinder divided by the large-diameter piston with each other, moving the ram integrally with the small-diameter piston rod moved by the moving member, and communicating the small-diameter cylinder with the large-diameter cylinder, thereby moving the large-diameter cylinder with a strong force by a working fluid supplied from the small-diameter cylinder.

Abstract: A ram driving method including the steps of fixing one end of a large-diameter piston rod (5R) integral with a large-diameter piston (5P) reciprocably included in a large-diameter cylinder (5) attached integrally to a ram (3) to a fixing unit (9), connecting one end of a small-diameter piston rod (7R) integral with a small-diameter piston (7P) reciprocably included in a small-diameter cylinder (7) integral with the large-diameter cylinder to a moving member (17) moved by a motor driving, integrally moving the small-diameter cylinder and the small-diameter piston and communicating a first compartment (5A) and a second compartment (5B) of the large-diameter cylinder divided by the large-diameter piston with each other, moving the ram integrally with the small-diameter piston rod moved by the moving member, and communicating the small-diameter cylinder with the large-diameter cylinder, thereby moving the large-diameter cylinder with a strong force by a working fluid supplied from the small-diameter cylinder.

Abstract: A door closer device includes an active lever which, when it is in an abnormal state-with respect to a latch lever, automatically returns a door to a normal state by means of a door closing operation. An active latch which is pivotably supported by an active lever is freely rotatable in one direction, but is rotation regulated by an arm of an active pawl, i.e. a cancel lever, in the other direction. This prevents the latch lever from jumping over the active latch and causing an abnormal state in which the active latch swings wide with respect to the latch lever.

Abstract: An apparatus for perfectly closing a door of a vehicle basically comprising a latch, a pawl, a motor, an active lever, a latch lever, a pawl switch, and a latch switch. The door closing begins with the action of the latch moving from the door half-closed to the closed position an shown by the switching off of the pawl switch with the latch switch turning on. The electric motor activates upon detecting the door half-closed position and stops when the closed position is reached.