Tools for injection moulding machines

A tool for use in a moulding machine comprising:

• a mould defining a mould cavity;
• means for introducing plastic material under pressure into the mould;
• and
• means for supporting a core insert in the mould cavity away from the mould during a moulding operation, said supporting means comprising at least one support member, means for mounting said support member for movement between a first position in which the member projects into the mould cavity so as to support the core insert at the commencement of a moulding operation and a second position in which the member is at least partially retracted from the mould cavity to disengage from the core insert, and means for urging said support member toward said first position, whereby when material is introduced into the mould cavity the support member is moved from the first position to the second position against the force of said urging means by the pressure of the material in the mould cavity during the moulding operation after the core insert has been enveloped in the material.