The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 23, 2008
Filed:
Dec. 27, 2004
John Robert Christian Friberg, Nacka, SE;
Knut Christian Schoeps, Tyresö, SE;
Torbjörn Rafael Sjöblom, Årsta, SE;
Erland Karlberg, Sundbyberg, SE;
John Robert Christian Friberg, Nacka, SE;
Knut Christian Schoeps, Tyresö, SE;
Torbjörn Rafael Sjöblom, Årsta, SE;
Erland Karlberg, Sundbyberg, SE;
Atlas Copco Tools AB, Nacka, SE;
Abstract
A method and a power tool system are provided for performing screw joint tightening using a pneumatic torque impulse power tool that is controlled by a control unit. A torque magnitude and a torque growth are calculated based on signals delivered by an angle sensor, and pressurized air is supplied to the power tool via a flow regulating valve which is successively adjustable between zero and full power flow. The flow regulating valve is controlled by the control unit to deliver a reduced power air flow to the power tool before and during a first delivered impulse, and then to deliver full power flow until a certain torque magnitude or a percentage of a target torque level is reached, whereafter the air supply flow is again reduced until the target torque level is reached, and when the target torque level is reached the air flow is shut off.