US Patent 9689639 Connection device for connecting limb to barrel of crossbow

A crossbow includes a barrel, a fixing member and a limb. The barrel includes a recess defined between the first and second ends of the barrel. The fixing member is engaged with the recess. A pin extends through the barrel and the fixing member to restrict the fixing member from disengaging from the recess. The pin includes a head and a shank which has a groove, a first notch and a second notch. The groove is located between the first and second notches. A positioning unit positions the pin to the barrel. A string is connected between two ends of the limb. The fixing member is able to quickly engaged with or disengaged from the recess of the barrel to quickly assemble or dis-assemble the limb relative to the barrel.