Tool holder assembly having cutting fluid supply circuit

A tool holder assembly which comprises, in combination, a tool holder connected to a spindle of a machine for rotation together therewith, a stationary support member rotatably coupled to said tool holder for rotatably supporting the tool holder connected to a fixed portion of the machine, a fluid supply circuit defined in the tool holder for supplying a cutting fluid from an external source thereof towards a fluid discharge passage defined in a cutting tool, said cutting tool being replaceably connected to and carried by the tool holder, and a vane-type displacement pump assembly coupled to said fluid supply circuit comprising a rotor, constituted by a portion of the tool holder, and a pump casing constituted by a portion of the stationary support member, said rotor further having first and second cylindrical portions with said first cylindrical portion being smaller in diameter than said second cylindrical portion and with said second cylindrical portion having at least one vane projecting therefrom, said vane-type displacement assembly being operable to forcibly pump the cutting fluid, which has been supplied from the external source thereof to the vane-type displace-ment pump, towards the fluid discharge passage in the cutting tool.