Patent ID: 7137458
Filing Date: 2006-11-21
Classification: B25D

Abstract:
1. An impact mechanism for a hammer drill, the hammer drill having a housing, the impact mechanism comprising an impact platform inside the housing, the impact platform being in connection with a drill bit for receiving impact forces and for transferring the impact forces to the drill bit; a plurality of cams placed inside the housing; and a plurality of hammers located inside the housing, each hammer being capable of reciprocation for exerting an impact force on the impact platform, wherein each of the cams is driven to interact with each of the hammers alternately such that the plurality of hammers are driven to reciprocate so as to generate the impact forces to the impact platform, both the plurality of cams and the plurality of hammers being angularly spaced apart and arranged about an axis of rotation, a cam disc rotatable about the axis of rotation and with the plurality of cams disposed on the cam disc, wherein rotation of the cam disc drives each of the cams to interact with each of the hammers sequentially, and the plurality of cams and the plurality of hammers configured such that each of at least some of the hammers being in interaction with one of the cams at a different state of a rise or fall cycle.