Lexicon DIY-Knowledge - Ratchet-controlled impact mechanism

Ratchet-controlled impact mechanism

Rastenschlagwerk

Mecanismo percutor de trinquete

Percussion mécanique de frappe à crabots

The ratchet-controlled impact mecanism generates the rotary-percussive action in impact drills. One of the two serrated and hardened ratchet discs is driven by the motor, the other one is firmly attached to the machine housing. In drill-only mode the ratchet discs are kept apart, whereas in impact mode the discs come into contact under the applied operator pressure.

The number of individual ratchet grooves on the disc surface determines the impact rate; the impact rate can vary from 30 000 to 50 000 impacts per minute depending on the type of machine.

Serrated striking mechanism
A in resting position:

B Feed motion:
serrations slide over each-other
and move the drill spindle forward

C Recoil motion:
serrations slide over the tips,
and due to the pressure spring and
operator pressure on machine serrations
fall back into their starting position

1 drill spindle (mobile in linear direction)
2 pressure spring
3 serrated disc fixed on drill spindle
4 serrated disc fixed in machine housing