Shofu Inc.

Akira Yoneda

Yusei Kadobayashi

Shuji Sakamoto

Ryouji Takei

A paste-type dental material is filled from an opening portion of a cartridge into a cylindrical portion by moving the opening portion of the cylindrical portion of the cartridge along a kneading surface, on which the paste-type dental material is kneaded, with the opening portion being inclined. The piston is placed on the kneading surface with a circular end surface of the piston contacting the kneading surface. The piston is inserted into the cylindrical portion by moving the opening portion of the cylindrical portion of the cartridge closer to the piston located on the kneading surface such that a piston-side tapered surface or the piston-side curved surface of the piston is fitted into the opening portion, and thereafter moving the one of the two ends of the cylindrical portion toward the kneading surface.

Piston easily mountable to cartridge and method of inserting the piston

A cartridge fitting portion of a cylindrical syringe made of a resin includes an end surface opening portion, a continuous opening portion continuous with the end surface opening portion, opened in a radial direction, and extending in an extending direction, and a recess portion configured to communicate with the end surface opening portion, the continuous opening portion, and an internal passage in a cylindrical body. The recess portion includes a flange fitting recess to be fitted with a flange portion of a cartridge, and a cylindrical portion fitting recess that communicates with the flange fitting recess and is fitted with a part of the cylindrical portion. A wall portion surrounding the cylindrical portion fitting recess of the cartridge fitting portion is configured to warp into snap engagement with the part of the cylindrical portion when the part of the cylindrical portion is inserted from the continuous opening portion.

Growing community of inventors

Soka, Japan

Akira Yoneda