The present invention is a dust collection assembly for capturing dust, debris and residue that is created during the process of drilling holes into a concrete ceiling. The dust collection assembly is used with a universal drill stand and a drill saddle which has an electric drill secured to it. The drill saddle further comprises a telescoping vacuum tube having a ceiling contact portion that encircles the drill bit at the portion of the drill bit where the drill bit enters the ceiling. As the drill bit begins to penetrate the ceiling, silica dust is generated and removed via the vacuum tube, which tube is connected to a vacuum source.

According to a tool clamping device for a machine tool, when a draw bar is moved in the axial direction of the main shaft of the tool clamping device, a steel ball moves in the radial direction of the main shaft so as to press the inner wall of the main shaft, forming an impression on the inner wall of the main shaft. This forms an inclined surface for generating a magnification effect for magnifying a spring force.

In one aspect, tool holders employing axial sleeves and dampening elements are described herein. Tool holders described herein define a central longitudinal axis and comprise a tool holder body having a connector portion and a holder portion. The connector portion is structured to engage a rotary machine and the holder portion is disposed opposite the connector portion and has an inner diameter surface comprising a plurality of axial grooves. Tool holders described herein further comprise a tool receiver structured to receive at least a portion of a cutting tool, the tool receiver having an outer diameter surface comprising a plurality of axial grooves. The tool receiver is mounted in the holder portion so as to align the axial grooves of the inner and outer diameter surfaces and define axial sleeves filled with dampening elements.

A universal drill stand for supporting a hand-held drill in an elevated and inverted position for drilling holes or inserting fasteners into a concrete ceiling or other overhead surface. The universal drill stand is extendable for use with varying ceiling heights. It eliminates the need for a worker to construct scaffolding or ascend a ladder or other elevating device to drill each hole, allowing the worker to remain safely on the floor and away from dust and debris associated with the drilling.