When the molten metal is at the proper level in the bath, float 1 is at a height at which link 2 tends to turn clockwise by the action of weight a and its left end forces lever 3 with its brake shoe against drum 4, thereby braking the drum. Through a train of gears and ratchet wheel 5, drum 4 is linked to chain sprocket 6. Ingot b of type-metal hangs from a chain running over sprocket 6. When the bath is at the proper level, the weight of ingot b, tending to turn sprocket 6, is counterbalanced by the friction force on brake drum 4. As the level drops, float 1 descends and lifts weight a of link 2. Then the brake shoe of lever 3 releases drum 4, enabling ingot b to sink into the bath and melt, thereby replenishing the metal in the bath.
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