Abstract: A retrievable toggle bolt for mounting an object on a drywall or other hollow wall structure includes a headless bolt having a threaded shaft with a terminal portion for insertion through a hole in the drywall. A toggle is engaged by a pivot-and-slide engagement configuration with the terminal portion of the headless bolt so that the toggle is free to pivot relative to the headless bolt about a pivot axis substantially perpendicular to the direction of elongation and the pivot axis is slidingly displaceable along part of the toggle roughly parallel to the length. The pivot-and-slide engagement configuration links the toggle to as to rotate together with the headless bolt about an axis parallel to the direction of extension. The result is a toggle bolt which can be switched between an insertion/removal state and a locked state by simply turning the headless bolt through a half-turn about its axis.

Abstract: A nail-guiding device comprising a sleeve having a linear passage therethrough, the linear passage having a first end at least partially covered by a flexible membrane with an opening, the membrane operative to engage and hold the nail, and a piston slideably engaged in the linear passage and operative to transfer the impact of the driver to the nail in a drive-in operation.

Abstract: A nail-guiding device comprising a sleeve having a linear passage therethrough, the linear passage having a first end at least partially covered by a flexible membrane with an opening, the membrane operative to engage and hold the nail, and a piston slideably engaged in the linear passage and operative to transfer the impact of the driver to the nail in a drive-in operation.

Abstract: A layer flock management system including a layer information accumulator operative to accumulate information regarding each of a multiplicity of layers in a flock and a floor layer identifier operative to identify floor layers from among the multiplicity of layers.

Abstract: An egg-collection system is described for collecting the eggs of laying hens or the like. The system comprises an enclosure defining a plurality of hen laying-stations in side by side relationship, each station including a floor for supporting a hen and formed with a discharge opening therethrough at one end of the respective station. The system further includes a drawer bar drawable over the floors so as to engage any eggs thereon to move them to and through the discharge opening onto a conveyor belt.