Rolled-print-medium holder device

A rolled-print-medium holder device for rotatably holding a rolled print medium having a center hollow portion, comprising:

• an axial member that extends in an axial direction and having both axial ends, the axial member being inserted through the center hollow portion;
• a holding member fixed to at least one of the both axial ends of the axial member and holding both sides of the rolled print medium;
• an outer fitting portion provided at either one of the axial member and the holding member, the outer fitting portion having an inner peripheral surface;
• an inner fitting portion provided at the other one of the axial member and the holding member, the inner fitting portion having an outer peripheral surface, the inner fitting portion being fitted into the outer fitting portion;
• and
• a weld portion provided at least at one of the inner fitting portion and the outer fitting portion, the weld portion being configured on either the inner fitting portion or the outer fitting portion such that the weld portion at least fixes the outer peripheral surface to the inner peripheral surface by ultrasonic welding,
• wherein the outer fitting portion is provided at the axial member and the inner fitting portion is provided at the holding member;
• wherein the outer fitting portion has an inner end surface that confronts the holding member;
• wherein the inner fitting portion includes an inner-end-surface confronting surface that confronts the inner end surface;
• wherein the weld portion includes a welding rib structured to have a substantially right angle triangle shape prior to welding, and to melt across a corner of the inner fitting portion after welding, the welding rib is formed at an outer periphery of the inner-end-surface confronting surface before welding, and includes, before welding:
• an outer side surface formed in the axial direction continuously from the outer peripheral surface;
• and
• a slanted surface forming a predetermined acute angle with the outer side surface;
• wherein a predetermined width of gap is formed between the outer peripheral surface and the inner peripheral surface when the inner fitting portion is fitted into the outer fitting portion.

A rolled-print-medium holder device for rotatably holding a rolled print medium having a center hollow portion, comprising:

• an axial member that extends in an axial direction and having both axial ends, the axial member being inserted through the center hollow portion;
• a holding member fixed to at least one of the both axial ends of the axial member and holding both sides of the rolled print medium;
• an outer fitting portion provided at either one of the axial member and the holding member, the outer fitting portion having an inner peripheral surface;
• an inner fitting portion provided at the other one of the axial member and the holding member, the inner fitting portion having an outer peripheral surface, the inner fitting portion being fitted into the outer fitting portion;
• and
• a weld portion provided at least at one of the inner fitting portion and the outer fitting portion, the weld portion being configured on either the inner fitting portion or the outer fitting portion such that the weld portion at least fixes the outer peripheral surface to the inner peripheral surface by ultrasonic welding,
• wherein the outer fitting portion is provided at the holding member and the inner fitting portion is provided at the axial member;
• wherein the inner fitting portion further has a holding-member confronting surface positioned at one axial end of the axial member, the holding-member confronting surface confronting an inner end surface of the holding member;
• wherein the welding portion includes a welding rib structured to have a substantially right angle triangle shape prior to welding, and to melt across a corner of the inner fitting portion after welding, the welding rib is formed at the inner end surface at a position corresponding to an outer periphery of the holding-member confronting surface before welding, and includes, before welding:
• an outer side surface formed to extend in the axial direction from the inner end surface;
• and
• a slanted surface forming a predetermined acute angle with the outer side surface;
• and
• wherein a predetermined width of gap is formed between the outer peripheral surface and the inner peripheral surface when the inner fitting portion is fitted into the outer fitting portion.