Patent ID: 7367749

Claim:
A backpack for back-mounting a compressed-air cylinder ( 50 ), fastened to the backpack by a cylinder fastening belt ( 40 ), when a user wears harnesses ( 30 ) and a waist belt ( 20 ), comprising: a backboard ( 100 ) which holds, on an upper portion thereof, one ends of the harnesses ( 30 ) and holds, at both sides of a middle portion thereof, the cylinder fastening belt ( 40 ), and comprises a pair of support hooks ( 105 ) that protrude from a lower portion of the backboard ( 100 ) while being spaced apart from each other to support thereon the compressed-air cylinder ( 50 ); a harness support ( 130 ) which holds, at opposite arms thereof, the other ends of the harnesses ( 30 ) and is coupled to a lower portion of a back surface of the backboard ( 100 ) so as to rotate upwards and downwards around a center thereof, with the opposite arms of the harness support ( 130 ) longitudinally extending horizontally in opposite directions; a waist protector ( 120 ) having a plate shape coupled to the backboard ( 100 ) at a position in the back of the harness support ( 130 ) so that both ends of the waist protector rotate upwards and downwards around a center of the waist protector, with ends of the waist belt ( 20 ) coupled to the ends of the waist protector, the waist protector thus covering and protecting the back of the user's waist; and a rotary unit for rotatably supporting both the harness support ( 130 ) and the waist protector ( 120 ) on the backboard ( 100 ).