Apparatus and method for delivering liquid coolant to drum mounted

Abstract

A roadway milling machine includes a hollow, cylindrically walled, shaft mounted, imperforate drum having tungsten carbide tipped steel cutting tools supported in tool holders extending generally radially outwardly from the cylindrical surface of the drum. The drum is moved over a roadway to be milled, and is rotated on its shaft to bring the cutting tools into operative contact with the roadway. Water is fed into the drum along a water access opening provided along the axis of the drum shaft; and this coolant leaves the drum through openings provided in the cylindrical drum wall, one adjacent to each cutting tool, in position where the coolant leaving the drum will impinge upon and cool its adjacent cutting tool. In order to limit the flow of water from the drum to the cutting tools and, at the same time, to prevent the necessarily small openings from clogging up, large openings can be provided through the cylindrical drum wall and well into the tool holders which extend integrally outwardly from that wall. A transverse opening through each tool holder is open to the tool holder large radial opening in the tool holder. This transverse opening is almost completely fitted with a bolt or other rod-like structure. The minimum cross-sectional area of the bolt is less than that of the transverse slot, and the bolt is free to vibrate or otherwise move under the impetus of the shock to the tool and tool holder as the tool strikes the roadway on each rotation of the drum.