Patent ID: 7331257

Claim:
A returning assembly of a spanner comprising: a driving portion having a receiving space for receiving a driving head and an ejecting unit; and the ejecting unit having a truncated conic shape; and a radial direction of the driving head having an inclined buckling surface; the buckling surface and an inner wall of the receiving space being formed with a semilunar buckling space for receiving the ejecting unit; the ejecting unit serving for controlling the returning directions of the driving head; and wherein a switch unit is installed in an inner hollow space of the driving head; the switch unit has a control end projected from the driving portion and a resisting end in the driving portion; the action of the resisting end is controlled by the operation of the control end; the resisting end of the switch unit resists against the ejecting unit in the buckling space; the shift of the ejecting unit is controlled by, the control end so as to operate the resisting end to control the returning operation of the driving head; and wherein the resisting end is formed by two sets of elastic units; each elastic unit is formed with a ball, a spring and a block, the spring is arranged between the ball and the block; the block resists against a lateral wall of the ejecting unit; and the ball of one set of the elastic unit is fixed to a recess in the driving head; and the ball of another set of the elastic unit is protruded to the inner hollow space of the driving head; as the ejecting unit extrudes the ball protruded to the inner hollow space will make the elastic unit to resist against the ejecting unit so as to confine the operation of the electing unit.