Abstract
The wrench 1 includes a head portion 300 to apply torque to a limited-access fastener (80, Figure 4), and a turning means 20. A first pivotal head portion 400 is attached to a second fixed head portion 500 by a pivot pin 60 and is urged closed by a resilient bias means (70, Figure 9). A push switch actuator (406, Figure 7) may be operable against the bias towards an open position. An inwardly curved profile fastener access 304, when pushed against the worked fastener drive flats 82, opens against the resilient bias. When the fastener is inserted the pivotal head portion automatically closes towards the fixed head portion. Further operation of the turning means in the drive torque direction (D, Figure 3) urges the fastener head 81 into engagement with equidistant torque application points (312, 313, 314, Figure 2) which form a triangular gripping profile 310, locking the fastener head within the inner profile 302. All radiused leading edges 315 face in the direction D. An arcuate pathway 321 is formed between 313 and 314. An inner drive profile 401 with planar guide face 322 aids and allows passage of points 84, permitting ratcheting in the reverse manner. [Figure 1]