Abstract: A chuck for a cylindrical rotary metal cutting tool, such as an end mill, is provided with a liquid coolant system. The chuck is constructed to direct cooling liquid onto a cutting tool secured in an axial bore defined therein with a plurality of converging liquid streams directed at the tool. The chuck is constructed with alternative passageways. Liquid coolant may be directed along a central, axial cooling liquid passageway remote from a transverse end face of the chuck. Liquid may pass radially outwardly therefrom through radial bores and into intersecting longitudinal cooling liquid distribution ducts which are inclined toward the axis of the tool holder and which terminate in outlet ports in the end face. The radial bores are plugged at locations radially outwardly from the intersection of the ducts with the radial bores.

Abstract: A chuck for a cylindrical, rotary, metal cutting tool, such as an end mill, is provided with a liquid coolant system. The chuck has a stationary, annular collar within which a tool holder rotates at high speed. An annular channel is defined between the collar and the tool holder and liquid coolant is pumped into the collar to the channel through an inlet on the collar. Internal ducts within the tool holder are directed inwardly at an angle from the annular channel toward an end face from which a rotary tool, such as an end mill protrudes. The ducts are also oriented at an angle corresponding to the helical spiral of flutes on the end mill and are radially aligned with troughs between the flutes. Liquid coolant, such as water, is forced from the annular channel through the ducts toward the troughs between the flutes. The liquid coolant travels all the way to the tip of the end mill to cool the bit and wash chips of metal therefrom with a minimum of water being thrown from the end mill by centrifugal force.