| 摘要 |
An adjustable wrench (1) has a handle member (2) having a curved first grip surface (10), to which is pivotally connected a movable jaw member (3) having a planar second grip surface (11) and a location surface (25) inclined thereto. The location of a pivot point (24), and curvature of the first grip surface (10), is such that with a nut (20) located by the location surface (25), a normal to a tangent at a point of contact X on the curved first grip surface (10) and a normal to the planar second grip surface (11) at an intersection (26) of the second grip surface (11) and the location surface (25), lie on opposite sides of the axis of symmetry (21) of the nut (20). The forces on the opposite faces (22, 23) of the nut (20) thus act to provide a turning moment on the nut (20), with a minimum tearing force along the faces (22, 23) of the nut (20). |
