Lock mechanism for a dispenser, roll of material and end plug therefor, and method for inserting a roll of material into such lock mechanism

A lock mechanism for a dispenser in combination with an exchangeable roll of material is described. The roll is provided with at least one end plug (50) with a bearing pin (44) for mounting the roll to the lock mechanism of the dispenser. The lock mechanism comprises a lock housing with a guide slot (14) for insertion of the bearing pin (44), the guide slot having a first section (14') with a first width and a second section (14) with a second width which is smaller than the first width. First and second sections (14', 14) are arranged in a direction perpendicular to the longitudinal extension of the guide slot (14) and in a longitudinal direction of the bearing pin (44) to be received. A sliding element (16) is mounted to the lock housing (12) and movable between a first positionclosing or narrowing the width of the guide slot (14) and a second position opening the guide slot (14). A lock element (18) is mounted to the sliding element (16) and rotationally movable around an axis of rotation (24) betw