Printed-wiring-board conveying method and printed-wiring-board conveyor

A printed-wiring-board conveyor, comprising:

• at least one wound-on belt;
• at least two rotatable wheels on which the wound-on belt is wound to have a straightly extending portion which straightly extends between the two rotatable wheels and which contacts one of opposite side surfaces of a printed wiring board;
• a contact-force producing device which causes the straightly extending portion of the wound-on belt and said one of the opposite side surfaces of the printed wiring board to contact each other with a contact force greater than a weight of the printed wiring board;
• and
• a drive device which drives at least one of the two rotatable wheels and thereby moves the wound-on belt and the printed wiring board while utilizing a frictional force produced between the wound-on belt and the printed wiring board.

A printed-wiring-board conveyor, comprising:

• a first wound-on member;
• a second wound-on member;
• two first rotatable wheels on which the first wound-on member is wound to have a straightly extending portion which straightly extends between the two first rotatable wheels and which contacts one of opposite side surfaces of a printed wiring board;
• two second rotatable wheels on which the second wound-on member is wound to have a straightly extending portion which straightly extends between the two second rotatable wheels and which contacts the other of the opposite side surfaces of the printed wiring board, wherein the respective straightly extending portions of the first and second wound-on members extend parallel to each other;
• a contact-force producing device which biases at least one of the respective straightly extending portions of the first and second wound-on members, toward the other of said respective straightly extending portions and thereby causes said respective straightly extending portions to sandwich the printed wiring board with a contact force greater than a weight of the printed wiring board;
• and
• a first drive device which drives at least one of the two first rotatable wheels and the two second rotatable wheels and thereby moves the first and second wound-on members and the printed wiring board while utilizing a frictional force produced between each of the first and second wound-on members and the printed wiring board,
• wherein the respective straightly extending portions of the first and second wound-on members are spaced from each other in a substantially horizontal direction, and
• wherein the conveyor further comprises at least two third rotatable wheels, at least one third wound-on member which is provided between the respective straightly extending portions of the first and second wound-on members and which is wound on the two third rotatable wheels to have a straightly extending portion which straightly extends parallel to the respective straightly extending portions of the first and second wound-on members, and a second drive device which drives at least one of the third rotatable wheels.

A printed-wiring-board conveyor comprising:

• at least one wound-on member;
• at least two rotatable wheels on which the wound-on member is wound to have a straightly extending portion which straightly extends between the two rotatable wheels and which contacts a printed wiring board;
• a contact-force producing device which causes the straightly extending portion of the wound-on member and the printed wiring board to contact each other with a contact force greater than a weight of the printed wiring board;
• and
• a drive device which drives at least one of the two rotatable wheels and thereby moves the wound-on member and the printed wiring board while utilizing a frictional force produced between the wound-on member and the printed wiring board,
• wherein the straightly extending portion of the wound-on member extends in a substantially horizontal direction, and
• wherein the contact-force producing device comprises:
• at least one freely rotatable member which is provided above the straightly extending portion of the wound-on member such that the freely rotatable member is freely rotatable about a substantially horizontal axis line perpendicular to the substantially horizontal direction, and which contacts an upper surface of the printed wiring board whose lower surface is supported on the straightly extending portion of the wound-on member;
• and
• a biasing device which biases the freely rotatable member toward the upper surface of the printed wiring board.