US Patent 7818884 Shaving apparatus

A shaving apparatus comprising a first shaving unit, including a first outer cutter (101,102) and a first undercutter (20) which cooperate together, a skin agitation member (12), a housing and a drive source (58) mounted in the housing. The outer cutter is mounted in a frame (10). The drive source is coupled to the first undercutter to provide oscillatory movement with respect to the frame at a frequency in the range 70 to 280 Hz. The drive source is also coupled to the skin agitation member to provide oscillatory movement at a frequency in the range 5 to 50 Hz. The first outer cutter is un-driven with respect to the frame.