Patent ID: 7721860

Claim:
A power coupling device comprising: first and second coupling members, at least one of which is capable of rotating about a common axis and relative to each other, said first coupling member having first and second pockets, said second coupling member having first and second notches; first and second struts arranged at least partly in said first and second pockets respectively, each of said first and second struts being urged to emerge from said first and second pockets respectively and capable of respectively engaging with one of said first and second notches, said first strut being capable of transmitting torque between said first and second coupling members only in a first direction, said second strut being capable of transmitting torque between said first and second coupling members only in a second direction that is opposite to said first direction; and first and second retainer plates arranged between said first and second coupling members and capable of moving in a plane perpendicular to said common axis and independently from each other, said first retainer plate having a first hole which said first or second strut can pass through, said second retainer plate having a second hole which said first or second strut can pass through when said second hole is aligned with said first hole and said first or second strut.