PURPOSE: To enable the sliding and discharging of one end of stacked articles from the region of a loading device even if the operation cycle time thereof is extremely short by disposing a piston in a cylinder with a space from head parts when initiating the operation thereof and by forming a pressurizing chamber.

CONSTITUTION: Using a cylinder 19 which has a pressurized air feed channel 35, a sealing material 37 and a direction changing roll 30 in head parts 28 and 29 and is equipped with traction means 33 and 34 to connect a piston 27 to a sliding parts carrier 32, layered articles 12 comprising an envelope 2 to be wrapped are slid from a loading device 5 to a packaging station 7. At the time of initiating the operation, the piston 27 is disposed placing a space from head parts 28 belonging to a cylinder 20 to form a pressurizing chamber 39. This, at the time of starting the operation, adds a very large compressed air cushion to the piston 27 which is quickly moved from the stationary position to a half portion 40 of the low pressure cylinder chamber and also, a carrier 32 which is connected to the cylinder chamber via bands 33 and 34 is quickly moved thereto.