Electronic click wrench

摘要

The wrench includes a handle 1 for applying torque through a shaft 2 to a working head 3. The shaft includes torque sensing means (10, 11, Figure 3) for calculating the torque applied to a work piece by the working head. A trigger mechanism is for sending a haptic feedback to a user by triggering a small angular movement of the handle relative to the working head when a set point torque is reached. The small movement of the handle relative to the head is an angular movement of the handle relative to the shaft. The trigger mechanism may be contained entirely within the handle and include a spring (19, Figure 7) that is wrapped around a rotary member 13 to prevent rotation of the member. When the set point torque is reached, an actuator 23 (e.g. solenoid) moves one end of the spring to reduce its grip on the member 13 and permit the small relative angular movement of the handle. The trigger may alternatively include a gear and rack or an eccentric cam and cam track. The wrench may be connected to a wireless microprocessor for recording maximum torque applied.