Cartridge for viscous-material dispenser

A cartridge comprising:

• a cylinder of a pneumatic dispenser that employs pressurized air to discharge a viscous material, the cylinder having a circular-shaped inner circumferential surface, a first end and a second end, and a discharge port at the first end configured to discharge the viscous material from the cylinder;
• and
• a plunger disposed within the cylinder and configured to divide an inner chamber of the cylinder into a filling chamber between the plunger and the first end, into which the viscous material is filled from the outside through the discharge port, and a pressurizing chamber between the plunger and the second end, into which the pressurized air is charged from the outside, the plunger comprising a substantially cylindrical main body portion that extends in an axial direction and has an outer circumferential surface;
• wherein the outer circumferential surface of the plunger is shaped such that a radial tubular clearance is defined in a circumferential direction between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder, and such that the radial tubular clearance continuously extends between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder both in the axial and circumferential directions,
• the outer circumferential surface of the plunger is also shaped such that, when the viscous material is filled into the filling chamber from the outside through the discharge port, the continuous radial tubular clearance is filled with a portion of the viscous material, thereby forming a seal body made of said portion of the viscous material between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder, said seal body blocking further viscous material from leaking from the filling chamber into the pressurizing chamber,
• the outer circumferential surface of the plunger includes multiple ridges that each have a component that extends in the axial direction of the plunger, the multiple ridges being spaced apart from each other in the circumferential direction of the plunger, and
• at least one of the ridges has a height dimension that increases in the axial direction from the filling chamber to the pressurizing chamber.

A cartridge comprising:

• a cylinder of a pneumatic dispenser that employs pressurized air to discharge a viscous material, the cylinder having a circular-shaped inner circumferential surface, a first end and a second end, and a discharge port at the first end configured to discharge the viscous material from the cylinder;
• and
• a plunger disposed within the cylinder and configured to divide an inner chamber of the cylinder into a filling chamber between the plunger and the first end, into which the viscous material is filled from the outside through the discharge port, and a pressurizing chamber between the plunger and the second end, into which the pressurized air is charged from the outside, the plunger comprising a substantially cylindrical main body portion that extends in an axial direction and has an outer circumferential surface;
• wherein the outer circumferential surface of the plunger is shaped such that a radial tubular clearance is defined in a circumferential direction between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder, and such that the radial tubular clearance continuously extends between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder both in the axial and circumferential directions,
• wherein the outer circumferential surface of the plunger is also shaped such that, when the viscous material is filled into the filling chamber from the outside through the discharge port, the continuous radial tubular clearance is filled with a portion of the viscous material, thereby forming a seal body made of said portion of the viscous material between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder, said seal body blocking further viscous material from leaking from the filling chamber into the pressurizing chamber,
• wherein the outer circumferential surface of the plunger includes multiple ridges that each have a component that extends in the axial direction of the plunger, the multiple ridges being spaced apart from each other in the circumferential direction of the plunger, and
• wherein at least one of the ridges is configured as multiple discrete ridge segments that are aligned in the axial direction and are spaced apart from each other in the axial direction.

A cartridge comprising:

• a cylinder of a pneumatic dispenser that employs pressurized air to discharge a viscous material, the cylinder having a circular-shaped inner circumferential surface, a first end and a second end, and a discharge port at the first end configured to discharge the viscous material from the cylinder;
• and
• a plunger disposed within the cylinder and configured to divide an inner chamber of the cylinder into a filling chamber between the plunger and the first end, into which the viscous material is filled from the outside through the discharge port, and a pressurizing chamber between the plunger and the second end, into which the pressurized air is charged from the outside, the plunger comprising a substantially cylindrical main body portion that extends in an axial direction and has an outer circumferential surface;
• wherein:
• the outer circumferential surface of the plunger is shaped such that a radial tubular clearance is defined in a circumferential direction between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder, and such that the radial tubular clearance continuously extends between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder both in the axial and circumferential directions;
• the outer circumferential surface of the plunger is also shaped such that, when the viscous material is filled into the filling chamber from the outside through the discharge port, the continuous radial tubular clearance is filled with a portion of the viscous material, thereby forming a seal body made of said portion of the viscous material between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder, said seal body blocking further viscous material from leaking from the filling chamber into the pressurizing chamber;
• the outer circumferential surface of the plunger includes multiple ridges that each have a component that extends in the axial direction of the plunger, the multiple ridges being spaced apart from each other in the circumferential direction of the plunger;
• each of the ridges has a height dimension in a radial direction of the plunger that increases in the axial direction from the filling chamber to the pressurizing chamber such that tip ends of the ridges are disposed more closely to the inner circumferential surface of the cylinder near the pressurizing chamber than near the filling chamber;
• and
• each of the ridges extends at least substantially along the entire axial length of the plunger.

A cartridge comprising:

• a cylinder of a dispenser configured to discharge a viscous material, the cylinder having a circular-shaped inner circumferential surface, a first end and a second end, and a discharge port disposed at the first end configured to discharge the viscous material from the cylinder, and
• a plunger disposed within the cylinder and configured to divide an inner chamber of the cylinder into an anterior chamber between the plunger and the first end, into which the viscous material is filled from the outside through the discharge port, and a posterior chamber opposite the anterior chamber between the plunger and the second end, the plunger comprising a substantially cylindrical main body portion that extends in an axial direction and has an outer circumferential surface;
• wherein the outer circumferential surface of the plunger is shaped such that a radial tubular clearance is defined in a circumferential direction between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder, and such that the radial tubular clearance continuously extends between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder both in the axial and circumferential directions,
• the outer circumferential surface of the plunger is also shaped such that, when the viscous material is filled into the anterior chamber from the outside through the discharge port, the radial tubular clearance is filled with a portion of the viscous material, thereby forming a seal body made of said portion of the viscous material between the outer circumferential surface of the plunger and the inner circumferential surface of the cylinder, said seal body blocking further viscous material from leaking from the anterior chamber into the posterior chamber,
• wherein the outer circumferential surface of the plunger includes multiple ridges that each extend in a direction at least having at least a direction extending in parallel in the axial direction of the plunger and that are spaced apart from each other in the circumferential direction of the plunger, and
• wherein each of the ridges is radially elastically deformable such that, when a tip end of the ridge is pressed against the inner circumferential surface of the cylinder, the tip end elastically deforms radially inwardly to prevent the ridge from strongly contacting the inner circumferential surface.