The backpack which you don't have to unfasten shoulder part and you can move into back and forth without open it.

摘要

PURPOSE: Provided is a packsack enabling to move back and froth without loosening shoulder strings which separates a shoulder string part and a packsack part and uses a rail and a rail rotation button to move back and forth so that it enables to use the packsack conveniently. CONSTITUTION: The packsack enabling to move back and froth without loosening the shoulder strings comprises the parts of: more than one string of upper and lower rail(8, 9) which are combined with more than one rail rotation button(5); more than one weight support fixed frame for the packsack(6) which are combined with more than one button to support and fix the weight of the packsack; and a rail locker(10) which adjusts the upper rail and the lower rail at the front chest of the shoulder string as user's body shape to lock.