Abstract: An apparatus to effect optimum delivery of dry bulk material from a hopper includes a device to provide vibratory stimulus to the hopper. The device for providing vibratory stimulus includes a device to identify the resonant frequency of the hopper and its contents at any time and to automatically continuously vary the frequency of the vibratory stimulus to maintain this frequency at, or close to, the resonant frequency of the hopper and its contents.

Abstract: The invention relates to an element of furniture such as a work surface comprised of a plate provided with at least three legs assembled respectively to the plate by an L-shaped attachment bracket. Each leg is comprised of a cylinder of substantially rectangular cross section and of an upper end portion including a cover. The upper portion of each leg is housed in a notch arranged at the edge of the plate such that each leg protrudes from the periphery of the plate. The notch is dimensioned to allow the housing of a second leg belonging to an adjacent work surface in parallel to the first leg. The L-shaped attachment bracket has an attachment portion arranged to attach to the plate and an end portion arranged to nest over the upper end portion of the cylinder of the leg. A fixing plate is housed in the upper portion of the cylinder of the leg. The fixing plate includes bores arranged in correspondence with bores provided on the end portion of the bracket that is nested over the cylinder of the leg.