Abstract: Material powder 17 is filled in a cavity 16 which is composed of a die 12 having a die hole 11 in a shape matching the contour of a green compact and a lower punch 13. The material powder 17 is temporarily compressed by an upper punch 14 and the lower punch 13 to obtain a preform 18. A punch-out pin 15a is inserted into the preform 18 to punch out a shape of a through-hole 3. The preform 18 is pressurized and compressed by both of the upper and lower punches 14, 13 to obtain a green compact 19. The punch-out pin 15a is pulled out from the green compact 19 and the green compact 19 is taken out from the cavity 16. Further, the green compact 19 is sintered and a pair of leg parts 24 connected continuously at a base part 23 and an undercut part 25 between the leg parts 24 are formed by cutting off a part of a peripheral wall 26 of a through-hole 25a.

Abstract: An automatic stretch-wrapping apparatus for wrapping a load, including empty PET bottles, with a stretchable film. The apparatus includes a turntable for placing the load thereon, and the stretchable film is supplied from a roll of stretchable film in a vertical position via film tensioning rollers to a gripper device. The gripper device is mounted on the turntable for gripping the leading end of the film and can rotate not only with the turntable but also relative to the turntable. Also, a swing arm device is arranged for movement toward and away from the gripper device to cooperate with the gripper device and includes pusher blades for pushing the film toward the gripping fingers of the gripper device, a heatsealer, and a cutter. It is possible to automatically wrap the load by the film in only one turn thereof.

Abstract: An unwrapping apparatus for unwrapping a palletized and stretch-wrapped load, including at the front side thereof lower grippers and upper grippers to grip the lower edge and upper edge of a stretchable film of the load, respectively, and a cutter unit for vertically cutting the stretchable film. The unwrapping apparatus includes at the rear side thereof a carriage having a platen to press the top of a load, a pair of swing arms carrying the upper grippers, and a pair of auxiliary film separating swing arms to separate the stretchable film from the rear corner portions of the load when the film is removed from the load by the main swing arms. The main swing arms and the auxiliary swing arms prevent the articles from being pulled and moved by the stretchable film in contact with the articles and thus falling down from the separate sheet in particular.

Abstract: An unwrapping apparatus for unwrapping a palletized and stretch-wrapped load, the apparatus enables the prevention of the articles from falling off and easy disposal of the used stretchable film. The apparatus comprises first and second upright frames between which a load to be unwrapped is conveyed, the first upright frame including two lower grippers for gripping a lower edge of the stretchable film, and an elevated cutter unit having two pairs of pinch rollers and a heat cutter. The second upright frame includes a carriage having a platen to press the top of the load to be unwrapped and a pair of swing arms symmetrically arranged on either side of the platen and extending toward the first upright frame. Upper grippers are secured to the swing arms, respectively. The stretchable film can be gripped during the cutting and unwrapping of the load to maintain tension and prevent the articles in the load from falling off. In addition, the used stretchable film can be discharged in a compressed, compact form.