A mould lifting device suitable for use in lifting and rotating a middle mould, two pivot portions being provided at two lateral surfaces of the middle mould, the mould lifting device comprising:
- a platform with a top surface;
- two longitudinal guide assemblies disposed at two sides of the platform, and each including:
- a longitudinal guide unit which includes a top portion, a bottom portion located a longitudinal distance away from the top portion, and a guide portion connected between the top portion and the bottom portion, and a longitudinal slide carriage which is movably disposed on the guide portion and includes a push portion;
- two transmissions for driving the longitudinal slide carriages to move;
- a power assembly for driving the transmissions to move;
- two lifting members disposed at both sides of the platform, and each including a lifting portion which is higher than the top surface of the platform;
- two push members fixed at the top portions of the longitudinal guide assemblies, and each including a push portion located between the top portion and the bottom portion of a corresponding one of the longitudinal guide assemblies;
- two pivot arms each including:
- a pivot connecting portion pivoted to a corresponding one of the longitudinal slide carriages, a pivot push portion which is located at one side of the pivot connecting portion to move away from or push against the push portion of a corresponding one of the push members, an abutting surface which is located at another side of the pivot connecting portion to push against or move away from a corresponding one of the push portions, and two restricting grooves which are located at another side of the pivot connecting portion and each include an opening which opens towards the top portion to restrict a corresponding one of the pivot portions of the middle mould, when the pivot push portion moves away from the push portion of the push members, the abutting surface will push against the push portion of the longitudinal slide carriages to lift the middle mould where the pivot portions are restricted in the restricting grooves, when the pivot push portion pushes against the push portion of the push members, the abutting surface will move away from the push portion of the longitudinal slide carriages to rotate the middle mould where the pivot portions are restricted in the restricting grooves;
- two covers disposed on the two pivot arms, and each including:
- a cover portion for covering the opening of a corresponding one of the restricting grooves, and a lifted portion to be pushed by the lifting portion of a corresponding one of the lifting members, when the lifted portion is pushed by the lifting portion of a corresponding one of the lifting members, the concerned cover will pivot by an angle to move the cover portion away from the opening of the corresponding one of the restricting grooves, when the lifted portion is moved away from the lifting portion of the corresponding one of the lifting members, the concerned cover will pivot an angle to make the cover portion cover the opening of the corresponding one of the restricting grooves.