Patent ID: 8122799

Claim:
An apparatus comprising: a table circular saw including a rotary circular saw blade and a dust discharge pipe, the rotary circular saw blade producing a flow of air during a cutting operation of a workpiece, so that cutting chips produced by the rotary circular saw blade flow into the dust discharge pipe with the flow of air; and a dust collecting device comprising: a dust collecting container; and an adaptor including a connector connected to the dust discharge pipe of the table circular saw, a container support disposed within the dust collecting container and configured to support the dust collecting container, and a back-flow preventing wall fixedly disposed on the container support, wherein: the container support includes opposite side walls, so that flow paths are defined between the side walls and the back-flow preventing wall; a cross sectional area of each of the flow paths decreases in a downstream direction with respect to the flow of air containing cutting chips flowing from the connector into the dust collecting container; the back-flow preventing wall is opposed to the connector and extends downward from the container support beyond a position opposed to a central axis of the connector; the back-flow preventing wall has a V-shape in a horizontal cross section, with a closed side opposite to an opening of the V-shape oriented toward a side of the connector, the back-flow preventing wall extends from the container support in a cantilever manner and in a direction substantially perpendicular to the downstream direction.