Patent ID: 7117601
Filing Date: 2006-10-10
Classification: B23D

Abstract:
1. A counterbalance mechanism for a reciprocating power tool comprising: a rocker arm having a lower drive section and an upper drive section, wherein the lower drive section is radially mountable on a rotary transmission mechanism so as to impart to the rocker arm pendular articulateness about a first pivotal axis transverse to the axis of the rotary transmission mechanism, an elongate reciprocating rod capable of sliding movement in an axial direction, wherein the elongate reciprocating rod has a proximal end and a distal end and is capable of coupling the upper drive section of the rocker arm to an external cutting element at the distal end, a counterweight mounted radially on the reciprocating rod and capable of sliding movement in an axial direction opposite to the direction of sliding movement of the reciprocating rod, a rocker cradle pivotally mountable so as to be imparted with pendular articulateness about a second pivotal axis transverse to the axis of the rotary transmission mechanism, wherein the rocker cradle has an upper section engaged with the counterweight and a lower section operatively connected or coupled to the rocker arm so that the rocker arm and the rocker cradle are imparted with opposite pendular articulateness about the first and second pivotal axes respectively.