Abstract: A smelting ladle includes a housing, a circulating working layer, a consumable working layer, and a permanent layer. The permanent layer is masoned or casted on an inner wall of the housing, the circulating working layer is casted on an inner wall of the permanent layer, and the consumable working layer is masoned on an inner wall of the circulating working layer.

Abstract: A smelting ladle and a method for improving use efficiency thereof. The smelting ladle includes a housing, a working layer, and a permanent layer. The method includes: 1) rebuilding the working layer to have an outer layer and an inner layer, the inner layer being a consumable working layer which contacts with molten steel and steel slag, and the outer layer being a circulating working layer which contacts with the permanent layer or directly contacts with the housing; 2) allowing the smelting ladle to work, when the thickness of the consumable working layer is reduced to be between 0 and 20 mm, removing a residue of the consumable working layer and masoning a new consumable working layer for the smelting ladle; and 3) repeating 2) until the circulating working layer reaches a designed service life thereof, and casting a new circulating working layer for the smelting ladle.

Abstract: A smelting ladle and a method for improving use efficiency thereof. The smelting ladle includes a housing, a working layer, and a permanent layer. The method includes: 1) rebuilding the working layer to have an outer layer and an inner layer, the inner layer being a consumable working layer which contacts with molten steel and steel slag, and the outer layer being a circulating working layer which contacts with the permanent layer or directly contacts with the housing; 2) allowing the smelting ladle to work, when the thickness of the consumable working layer is reduced to be between 0 and 20 mm, removing a residue of the consumable working layer and masoning a new consumable working layer for the smelting ladle; and 3) repeating 2) until the circulating working layer reaches a designed service life thereof, and casting a new circulating working layer for the smelting ladle.

Abstract: The present invention relates to a self-tightening keyless chuck to enable electric percussive drills to grip a tool shank. The chuck includes a rear sleeve, a body, a bearing ring, a bearing assembly, a nut, a jaw, a front sleeve and a stopper and so on. The bearing assembly utilizing a ball bearing is positioned with a circumferential arcuate race with a fixed depth, and the bottom surfaces of said circumferential arcuate race are provided with a plurality of ball-shape grooves. During the chuck grips a tool shank, the balls of said ball-bearing enter into the ball-shape grooves and are locked there, so as to prevent the tool from loosening due to the percussion vibration. In addition, the front sleeve engages with a nut through radial smooth press-fit to securely transmit a torque.

Abstract: The present invention relates to a self-tightening keyless chuck to enable electric percussive drills to grip a tool shank. The chuck includes a rear sleeve, a body, a bearing ring, a bearing assembly, a nut, a jaw, a front sleeve and a stopper and so on. The bearing assembly utilizing a ball bearing is positioned with a circumferential arcuate race with a fixed depth, and the bottom surfaces of said circumferential arcuate race are provided with a plurality of ball-shape grooves. During the chuck grips a tool shank, the balls of said ball-bearing enter into the ball-shape grooves and are locked there, so as to prevent the tool from loosening due to the percussion vibration. In addition, the front sleeve engages with said nut through radial smooth press-fit to securely transmit a torque.