Friction Shaft for Slitter

A friction shaft for a slitter that has winding tubes disposed on an outer surface thereof to roll unit materials formed by cutting a raw material such as various kinds of paper, fabric, or film with predetermined intervals,

• the friction shaft comprising a first rotary shaft rotated by a driving motor and supplied with compressed air from an air supplier,
• wherein, in the first rotary shaft (10), a moving passage elongated in a longitudinal direction of the first rotary shaft is formed in the first rotary shaft, first and second supply holes for receiving the compressed air are formed at a side of the outer surface to be connected with the moving passage, first discharge holes are elongated at an opposite side of the outer surface in the longitudinal direction of the first rotary shaft to be connected with the moving passage and are arranged with predetermined intervals in a circumferential direction of the moving passage, second discharge holes are elongated at the opposite side of the outer surface in the longitudinal direction of the first rotary shaft and are arranged with predetermined intervals along a circumference of the first rotary shaft between the first discharge holes, locking steps protrude from open ends of the second discharge holes, connection holes connecting the moving passage and the second discharge holes are formed therein, fitting holes are formed on outer surfaces around the first discharge holes with predetermined intervals in the longitudinal direction of the first rotary shaft, and first fastening holes are formed in the fitting holes,
• the friction shaft includes tubes disposed in the second discharge holes and having supply holes connected with the connection holes,
• the friction shaft includes lug bodies for torque that are disposed adjacent to each other in a longitudinal direction of the second discharge holes, have installation holes longitudinally formed therein, have insertion holes connected with the installation holes and formed on an outer surface with predetermined intervals in a longitudinal direction thereof, have locking portions protruding outward from both sides of the installation holes to be locked to the locking steps, and have a guide hole elongated in the longitudinal direction on the outer surface to be connected with the insertion holes,
• the friction shaft includes first fixed shafts disposed in the installation holes,
• the friction shaft includes a plurality of lug rollers for torque that is inserted in the insertion holes to be rotated around the first fixed shafts by first bearings,
• the friction shaft includes brake pads inserted in the guide holes (21d) between the tubes and the lug bodies for torque and having friction portions protruding from outer surfaces thereof with predetermined intervals in a longitudinal direction to be in close contact with the lug rollers for torque,
• the friction shaft includes a second rotary shaft disposed to be movable through the moving passage,
• wherein, in the second rotary shaft, moving grooves for sending compressed air supplied from the second supply hole to the connection holes are formed in a circular shape and elongated on a side of an outer surface in a longitudinal direction of the second rotary shaft, and second fastening holes are formed with predetermined intervals on an opposite side of the outer surface to face the first discharge holes and are formed with predetermined intervals around the second rotary shaft to face the first discharge holes,
• the friction shaft includes guide members having third fastening holes formed on outer surfaces thereof to be fitted to the second fastening holes through fasteners, and having first inclined surfaces formed on outer surfaces facing the first discharge holes,
• the friction shaft includes lug bodies for clamping that are disposed adjacent to each other in a longitudinal direction of the first discharge holes, have second inclined surfaces formed on a side of an outer surface to be guided by the first inclined surfaces, have insertion holes formed on an opposite side of the outer surface, have installation holes formed at both sides of the insertion hole, and have locking portions protruding at both sides of the outer surface adjacent to the second inclined surfaces and the insertion holes,
• the friction shaft includes second fixed shafts disposed in the installation holes,
• the friction shaft includes a plurality of lug rollers for clamping that is inserted in the insertion holes to be rotated around the second fixed shafts by second bearings,
• the friction shaft includes covers fitted in the fitting holes, having fourth fastening holes formed on outer surfaces to be fitted to the first fastening holes through the fasteners, and locking the locking portions,
• the friction shaft includes a first elastic member disposed between the moving passage and the second rotary shaft to return the second rotary shaft that has been moved,
• the friction shaft includes second elastic members disposed between the locking portions and the covers to return the lug bodies for clamping that have been moved,
• when compressed air is supplied to the moving passage through the first supply hole, the second rotary shaft is moved through the moving passage by pressure of the compressed air, the lug bodies for clamping are moved while the second inclined surfaces are guided by the first inclined surfaces, the lug rollers for clamping are discharged out of the first discharge holes, the discharged lug rollers for clamping come in close contact with inner surfaces of the winding tubes, and the second supply hole, the moving grooves, and the connection holes are connected by the moved second rotary shaft, and
• when the compressed air is supplied to the supply holes of the tubes sequentially through the second supply hole, the moving holes, and the connection holes, the tubes are expanded by pressure of the compressed air, the lug bodies for torque and the brake pads are moved, the lug rollers for torque are discharged out of the second discharge holes, and the discharged lug rollers for torque come in close contact with the friction portions and the inner surfaces of the winding tubes.