Rotary cutting tool with vibration damping device

A helical end mill, comprising:

• a cutter body having a forward end, a rearward end, the cutter body including a head, a shank, and a cavity extending from the rearward end toward the forward end along a central, longitudinal axis of the cutter body, the head further including at least one cutting insert mounted in a pocket adjacent to a helical chip flute;
• and
• a vibration damping device disposed within the cavity, the vibration damping device including a stop member at one end, a threaded member at an opposite end capable of being threadingly received within the cavity, a plurality of solid, cylindrical-shaped weight elements disposed between the stop member and the threaded member, and a spring disposed between the stop member and the plurality of weight elements for biasing the plurality of weight elements, the plurality of weight elements being cylindrical in shape and having a different outside diameter from each other to cause the plurality of weight elements to vibrate in the cavity at a plurality of different frequencies,
• wherein one end of the threaded member is non-threaded and contacting the plurality of weight elements such that the plurality of weight elements are slightly frictionally restrained against absolute free lateral movement within the cavity, and wherein an opposite end of the threaded member includes a recess to allow the threaded member to be threaded into the cavity, and
• wherein at least some of the plurality of frequencies of the plurality of weight elements are different than a fundamental chatter frequency of the cutting tool, thereby dampening vibration of the rotary cutting tool during a machining operation.

A rotary cutting tool, comprising:

• a cutter body having a forward end, a rearward end, the cutter body including a head, a shank, and a cavity extending from the rearward end toward the forward end along a central, longitudinal axis of the cutter body, the cavity having threads at one end thereof, the head including at least one chip groove extending rearwardly from the forward end, the head further including at least one cutting insert mounted in a pocket adjacent to at least one chip groove;
• and
• a vibration damping device disposed within the cavity, the vibration damping device including a stop member at one end of the cavity, a threaded member at an opposite end of the cavity, a plurality of weight elements disposed between the stop member and the threaded member, and a biasing member disposed between the stop member and the plurality of weight elements,
• wherein at least one of the plurality of weight elements having an outside diameter that is different than an outside diameter of another one of the plurality of weight elements to cause the plurality of weight elements to vibrate in the cavity at a plurality of different frequencies, and
• wherein one end of the threaded member is non-threaded and contacting the plurality of weight elements such that the plurality of weight elements are slightly frictionally restrained against absolute free lateral movement within the cavity, and wherein an opposite end of the threaded member includes a recess to allow the threaded member to be threaded into the cavity, and
• wherein at least one of the plurality of frequencies is different than a fundamental chatter frequency of the cutting tool, thereby dampening vibration of the rotary cutting tool during a machining operation.