Impact mechanism for a hammer tool

The impact mechanism 208 for an impact tool (100, Figure 1) with a housing 102 includes a piston 218 slidably disposed in the housing and adapted to transfer an impact force to a tool bit 210. First, second, and third electromagnetic coils 222, 224, 238, are disposed between the piston and the housing. The coils are alternately activated to generate respective magnetic fields to cause the piston to move. Activation of the first electromagnetic coil 222 causes the piston to move towards the tool bit. Activation of the third electromagnetic coil 238 causes the piston to move away from the tool bit. A sleeve 220 may be disposed between the piston and the coils and may be made from a nylon composite material. The housing may include an opening 226 to receive the tool bit and/or include a threaded portion to couple with a tool bit holding mechanism 128. The piston may include a spacer 234 e.g. a washer or puck, at an end of the piston and composed of a non-magnetic material such as titanium. The second coil 224 may be disposed between the first and third coils. The third coil 238 may be activated longer than the others.