Adjustable mount for backpack

In combination with backpack having a rear wall and shoulder straps, an adjustable mount comprising:

• a base plate attachable or attached to the rear wall of the backpack and formed with two seats spaced apart in an adjustment direction;
• respective coupling drums rotatable in the seats;
• a cover on the base plate and forming therewith a housing;
• guide rails in the housing on the base plate and extending in the direction;
• a slide in the housing and movable along the guide rails in the direction between end positions;
• a support plate outside the housing, attached to the shoulder straps, and connected through the cover with the slide for joint movement therewith in the direction;
• a control element coupled to the slide and movable between a locking position arresting the slide on the base plate and a release position allowing the slide to move steplessly in the direction on the rails relative to the base plate, the control element being accessible by a wearer of the backpack while same is on a back of the wearer;
• a ball chain spanned over and rotationally coupling the drums and fixed to the slide for joint movement therewith in the direction, one of the drums being formed with a hole fitted with the control element for rotation of the one drum and thus displacement of the chain, slide, and support in the direction;
• and
• a formation on the base plate fittable with the coupling element for preventing rotation thereof and movement of the slide in the direction.