Patent ID: 8443702

Claim:
A torque wrench comprising: a head portion having a cylindrical cam shaft rotatably disposed with a plurality of cam parts formed on an outer circumference thereof, the cam parts each having a torque transmitting cam surface and a torque non-transmitting cam surface, and a torque transmission shaft coaxially disposed inside the cam shaft for tightening an object to be tightened via a ratchet mechanism; a tubular lever fixed to a rear end portion of the head portion and accommodating therein a spring force transmitting rod biased by a torque setting spring; a roller member engaged with the cam part; and a roller support lever member rotatably mounted in the head portion via a support shaft for rotatably supporting the roller member and for applying the spring force via the spring force transmitting rod to the roller member so as to cause a tightening reaction force to be applied to the roller member, wherein the roller support lever member is configured such that a distance from the support shaft to a point of application of force of the spring force transmitting rod is longer than a distance from the support shaft to the roller member.