Bidirectional Mechanical Converting Unit

A screwdriver, comprising:

• a handle;
• a main shaft;
• a reversing element, which is fixedly coupled at one end to the main shaft and configured to drive the main shaft to rotate;
• a follower gear, a capstan gear, a transmission seat and at least one idle gear, the follower gear, the transmission seat and the capstan gear sleeved on the reversing element in sequence;
• the transmission seat provided thereon with at least one idle gear axle, the at least one idle gear mounted on the respective idle gear axle so that the idle gear be located between the follower gear and the capstan gear to serve for power transmission;
• one end of the capstan gear fixedly coupled to the handle, the handle configured for input of a torque for causing the capstan gear to rotate so that the capstan gear drives the follower gear rotate oppositely via the idle gear;
• a holding ring, which is sleeved on the transmission seat and fixedly coupled to the transmission seat,
• the reversing element provided with a first pawl compartment in its portion corresponding to the follower gear and a second pawl compartment in its portion corresponding to the capstan gear, the first pawl compartment provided therein with a first pawl and a second pawl, which can swing;
• the follower gear provided on its inner circumferential surface with an inner ratchet circumference, the inner ratchet circumference intermeshing with the first pawl or the second pawl;
• the second pawl compartment therein with a third pawl and a fourth pawl, which can swing;
• the capstan gear provided on its inner circumferential surface with an inner ratchet circumference, the inner ratchet circumference intermeshing with the third pawl or the fourth pawl;
• the first pawl and the third pawl located on the same side, the second pawl and the fourth pawl located on an opposing other side;
• wherein when the first pawl intermeshes with the inner ratchet circumference of the follower gear and when the third pawl intermeshes with the inner ratchet circumference of the capstan gear, irrespective of the torque input from the handle in a first direction or in a second direction, the reversing element always drives the main shaft to rotate in the first direction;
• when the second pawl intermeshes with the inner ratchet circumference of the follower gear and when the fourth pawl intermeshes with the inner ratchet circumference of the capstan gear, irrespective of the torque input from the handle in the first direction or in the second direction, the reversing element always drives the main shaft to rotate in the second direction, where the first direction and the second direction are opposite directions,
• the reversing element also provided therein with a reversing pin, the reversing element provided with a chuck disposed thereover, the reversing element provided in its position corresponding to the chuck with a transverse slot, through which a coupling member is passed;
• one end of the coupling member coupled to the reversing pin, the other end coupled to the chuck, the chuck configured to be driven by an external force to drive the reversing pin to move,
• the reversing pin provided thereon with driving members for driving the pawls to move;
• by switching positions of the reversing pin, the driving members driving the respective pawls to move;
• wherein when the reversing pin moves to a first position, the first pawl protrudes out of the first pawl compartment and intermeshes with the inner ratchet circumference of the follower gear and the third pawl protrudes out of the second pawl compartment and intermeshes with the inner ratchet circumference of the capstan gear, enabling the main shaft to rotate, when driven, always in the second direction;
• when the reversing pin moves to a second position, the second pawl protrudes out of the first pawl compartment and intermeshes with the inner ratchet circumference of the follower gear and the fourth pawl protrudes out of the second pawl compartment and intermeshes the inner ratchet circumference of the capstan gear, enabling the main shaft to rotate, when driven, always in the first direction.