| 摘要 |
<p>A safety wheel block (100) is disclosed. The block (100) will prevent a load it is being used hoist from falling if the rope end being hauled upon (510) is released. The block (100) has first wheel (320) and second wheel (340) on a carriage (310) that is connected by a pivot (410) to a base (212) suspended using a ring (230). The rope is threaded over the wheels but under the base (212). The pivot axis (A) is positioned such that when a pulling force (TT) and the tension force (TL) created by the weight of the object being hoisted are substantially equal, the pivoting arrangement remains in a first position but will move to a second position when the pulling force (TT) at the tension end of the rope (510) is rapidly reduced. In the first position the rope may travel freely over the wheels. In the second position the carriage (310) pivots up, lifting the second wheel (340) and causing the rope to contact with the base (212) and be pressed onto a breaking pad (330) within the carriage (310). As long the forces on the rope are unbalanced the weight of the object being hoisted will bring about this breaking action. The actuation of the breaking action will actuate a further process such an alarm.</p> |
