Patent ID: 7604640

Claim:
A device for applying rotary impact comprising: a torsion spring defined by a diameter and width and having a first end and a second end; a body comprising a proximal end configured for rigid attachment to a tool; a spring cavity disposed on a longitudinal axis for retaining at least a portion of the torsion spring; an opening configured for fixed connection to the first end of the torsion spring; and a shaft cavity disposed on the longitudinal axis for retaining at least a portion of a shaft; a shaft assembly comprising: a shaft comprising a proximal end adapted for rotatable connection to the body and a distal end adapted for connection to a driver tip; and an impact disk rigidly connected to the shaft comprising one or more contact sections defined by an arc length and profile for slidable contact with the second end of the torsion spring and one or more non-contact sections of selected arc length separating the one or more contact sections, wherein rotation of the body about the shaft when the second end is in contact with a first contact section changes the torsion spring configuration to generate potential energy in the torsion spring, and wherein further rotation of the body about the shaft causes the second end to be in a non-contact section, wherein the torsion spring is configured to convert the generated potential energy into kinetic energy when the second end is in the non-contact section, causing the second end to transition across the non-contact section and contact a second contact section, wherein the contact with the second contact section converts the kinetic energy in the torsion spring to a rotary impact on the shaft.