Patent ID: 7219583
Filing Date: 2007-05-22
Classification: B25B,F16D

Abstract:
1. A pneumatic screwdriver having an adjustable clockwise torque and a maximum counterclockwise torque, and said pneumatic screwdriver having a transmission seat linked thereon, and said transmission seat having a through hole and a cam rod passing through said through hole, and said cam rod at an end having a steel ball seat, and said steel ball seat and said transmission seat including at least one corresponding steel ball hole and a steel ball groove, and a steel ball being installed between said steel ball hole and said steel ball groove, and a resilient device passing through said cam rod tightly pressing said transmission seat and said steel ball seat, such that said cam rod and said transmission seat form a link relation, characterized in that: said steel ball hole includes a clockwise rotating area and a counterclockwise rotating area, and a sidewall of said clockwise rotating area includes a first leaning portion for pressing said steel ball when said power axle is rotated clockwise, and said steel ball presses said resilient device to separate said steel ball from said steel ball groove, when the reacting force of said cam rod being rotated clockwise is greater than the compressing strength of said resilient device, said steel ball seat, said transmission seat, and said steel ball slide with each other, and a sidewall of said counterclockwise rotating area includes a second leaning portion for pressing said steel ball, when said power axle is rotated counterclockwise, and said second leaning portion includes an inclination with respect to said first leaning portion, and said inclination stops said steel ball from being separated from said steel ball groove.