Fig. 2-13: hydraulic long-core-pulling mechanism I -fixed plate, 2- long core, 3- moving plate 3. Power-driven Core-pulling Such mechanism pulls out the active cores by utilizing the mold opening force of injection machine and through the driving of parts. Such mechanisms as angle pin core-pulling, gear and rack core-pulling etc have been extensively applied in production 4. Side Core-pulling Mechanism Driven by Spring When the side concave of plastic parts is shallow and requires relatively smaller pulling spring or ebonite can be used to achieve core-pulling. See Fig 2-14, 2-15 and 2-16 Fig2-14: ebonite core-pulling Fig 2-15: spring core-pulling (a)close mold; (b)open mold core-pulling (a)close mold; (b)open mold core-pulling P区 Fig 2-16: spring core-pulling fixed mold (a)close mold; (b)open mold core-pulling 2.2.2 Design of Angle Pin Core-pulling Mechanism 1. Principle of DesignFig.2-13: hydraulic long-core-pulling mechanism 1- fixed plate; 2- long core; 3- moving plate 3. Power-driven Core-pulling Such mechanism pulls out the active cores by utilizing the mold opening force of injection machine and through the driving of parts. Such mechanisms as angle pin core-pulling, gear and rack core-pulling etc. have been extensively applied in production. 4. Side Core-pulling Mechanism Driven by Spring When the side concave of plastic parts is shallow and requires relatively smaller pulling force, spring or ebonite can be used to achieve core-pulling. See Fig.2-14, 2-15 and 2-16. Fig.2-14: ebonite core-pulling Fig.2-15: spring core-pulling (a) close mold; (b) open mold core-pulling (a) close mold; (b) open mold core-pulling Fig.2-16: spring core-pulling fixed mold (a) close mold; (b) open mold core-pulling 2.2.2 Design of Angle Pin Core-pulling Mechanism 1. Principle of Design