Conversion apparatus for injection moulding machines

Claim 2

An injection moulding machine having platens (3, 4) relatively movable toward and away from each other respectively for fully closing a mould (2) mounted between the platens to form a closed cavity (8) into which plastics material is injected for forming an article and for fully opening the mould (2) for removal of the completed article, characterised by apparatus (20) mounted between the platens (3, 4) for partially opening the mould (2) to enlarge the closed cavity (8), whereby the material injected into the cavity (8) may foam, prior to the platens (3, 4) being moved apart.

Claim 3

An injection moulding machine according to Claim 1, in which said apparatus includes a mould carrier (22) attached to one of the platens (4) and movable relative to the platen (4) between advanced an&retracted limit positions in which, with the platens (3, 4) closed, the mould (2) is respectively fully closed and partially open, and means (27) for locking the mould carrier (22) in its advanced position.

Claim 4

An injection moulding machine according to Claim 2 including hydraulic drive means (26) for moving the mould carrier (22).

Claim 5

An injection moulding machine according to Claim 3, in which the hydraulic drive comprises one or more rams (26) mounted on said one platen (4) for driving the mould carrier (22) towards its advanced position, separate means (29, 32) serving to drive the carrier (22) in the opposite direction for enlarging-the mould cavity (8).

Claim 6

An injection moulding machine according to Claim 3, in which the hydraulic drive comprises a double acting arrangement (41) mounted on said one platen (4) for driving the mould carrier (22) in both directions.

Claim 7

An injection moulding machine according to Claim 2, 3, 4 or 5, in which said one platen (4) is movable and the other platen (3) is fixed.

Claim 8

Conversion apparatus (20) for converting an injection moulding machine in which the platens (3, 4) have a fixed closad position into one which permits expansion of a mould (2) mounted between the platens between a fully closed position defining a closed cavity (8) and a partially open position in which the closed cavity (8) is enlarged, whereby plastics material injected into the mould (2) when it is fully closed may foam when the mould is partially open, characterised in that the apparatus (20) comprises an attachment (21) adapted to be mounted on one of the platens (4), said attachment (21) including a mould carrier (22) movable relative to the platen (4) between advanced and retracted limit positions in which, with the platens (3, 4) closed, the mould (2) is respectively fully closed and partially open, hydraulic drive means (26, 41) for moving the mould carrier, and means (27) for locking the mould carrier (22) in its advanced position.

Claim 9

Conversion apparatus (20) for converting an injection moulding machine in which the platens (3, 4) have a fixed closad position into one which permits expansion of a mould (2) mounted between the platens between a fully closed position defining a closed cavity (8) and a partially open position in which the closed cavity (8) is enlarged, whereby plastics material injected into the mould (2) when it is fully closed may foam when the mould is partially open, characterised in that the apparatus (20) comprises an attachment (21) adapted to be mounted on one of the platens (4), said attachment (21) including a mould carrier (22) movable relative to the platen (4) between advanced and retracted limit positions in which, with the platens (3, 4) closed, the mould (2) is respectively fully closed and partially open, hydraulic drive means (26, 41) for moving the mould carrier, and means (27) for locking the mould carrier (22) in its advanced position.

Claim 10

Conversion apparatus according to Claim 7, in which the hydraulic drive comprises one or-more rams (26) adapted to be mounted on said one platen (4) for driving the mould carrier (22) towards its advanced position, separate means (29, 32) serving to drive the carrier (22) in the opposite direction for enlarging the mould cavity (8).

Claim 11

Conversion apparatus according to Claim 7, in which the hydraulic drive comprises a double acting arrangement (41) adapted to be mounted on said one platen (4) for driving the mould carrier (22) in both directions.

Claim 12

An expanding mould assembly for an injection moulding machine in which the platens (3, 4) have a fixed closed position, characterised in that the assembly (2) comprises first and second mould parts (6, 7) which are relatively movable in the closed position of the platens (3, 4) between a fully closed position in which they form a closed cavity (8) and a partially open position in which the closed cavity (8) is enlarged, whereby plastics material injected into the cavity (8) in the fully closed position of the mould (2) may foam when the cavity is enlarged.

Claim 13

An expanding mould assembly for an injection moulding machine in which the platens (3, 4) have a fixed closed position, characterised in that the assembly (2) comprises first and second mould parts (6, 7) which are relatively movable in the closed position of the platens (3, 4) between a fully closed position in which they form a closed cavity (8) and a partially open position in which the closed cavity (8) is enlarged, whereby plastics material injected into the cavity (8) in the fully closed position of the mould (2) may foam when the cavity is enlarged.