All-metal expansible anchor and nail assembly

摘要

The assembly is adapted to fasten to masonry a fixture or other object having a mounting hole. The anchor which goes through the fixture mounting hole into a hole drilled in the masonry, has a head that then engages the fixture and an expansible body projecting from the head into the drilled hole whereby when the nail is driven into the hollow anchor, the anchor body then expands against the wall of the hole to lock the anchor in it. The expander nail has a head whose diameter is greater than that of the drilled hole and a shank of smaller diameter joined to the underside of the nail head by a junction section of progressively increasing diameter whereby the shank gradually merges with the head. Countersunk in the head of the anchor is a well that conforms to the shape of the nail head and the junction section, the well receiving and nesting the nail head and junction section when hammer blows are applied to the nail head. The force of these blows is transferred by the nail head and the junction section to the surrounding region in the anchor head to develop compressive stresses in it that act to retard further advance of the nail and to prevent the production of shear stresses that may cause the anchor head to separate from the body of the anchor.