Preform molding unit equipped with a rotatable core holder

Unit (4) for molding preforms (2) made of plastic material, with each preform (2) having a body (15) and a neck (17) in the extension of the body (15), with this unit (4) comprising:

• A frame (19),
• A mold holder (27) that is integral with the frame (19) and that carries at least one mold body (29) bearing the imprint of an outer face (33) of the body (15) of the preform (2), with this mold body (29) extending around a molding axis (M);
• A movable apparatus (60) including a carriage (61) and at least one oblong core (64A, 64B) bearing the imprint of an inner face (65) of the body (15) of the preform (2), with the carriage (61) being mounted to move in relation to the frame (19) between:
• A molding position in which the core (64A, 64B) is housed in the mold body (29), and
• A demolding position in which the core (64A, 64B) is axially separated from the mold body (29),
• wherein the movable apparatus (60) also comprises:
• A core holder (62) mounted on the carriage (61), with this core holder (62) carrying at least one primary core (64A) and one secondary core (64B) and being movable in rotation in relation to the carriage (61), in the demolding position of the latter, around an axis (R) of rotation that is parallel to the molding axis (M), between:
• A first alignment position in which the primary core (64A) extends in the alignment of the mold body (29) while the secondary core (64B) is offset in relation to the mold body (29), and
• A second alignment position in which the primary core (64A) and the secondary core (64B) are transposed;
• wherein the mold holder (27) includes a number of mold bodies (29), and the core holder (62) carries a number of primary cores (64A) and a number of secondary cores (64B);
• and
• wherein the mold bodies (29) are placed side by side along a curved line.

Unit (4) for molding preforms (2) made of plastic material, with each preform (2) having a body (15) and a neck (17) in the extension of the body (15), with this unit (4) comprising:

• A frame (19),
• A mold holder (27) that is integral with the frame (19) and that carries at least one mold body (29) bearing the imprint of an outer face (33) of the body (15) of the preform (2), with this mold body (29) extending around a molding axis (M);
• A movable apparatus (60) including a carriage (61) and at least one oblong core (64A, 64B) bearing the imprint of an inner face (65) of the body (15) of the preform (2), with the carriage (61) being mounted to move in relation to the frame (19) between:
• A molding position in which the core (64A, 64B) is housed in the mold body (29), and
• A demolding position in which the core (64A, 64B) is axially separated from the mold body (29),
• wherein the movable apparatus (60) also comprises:
• A core holder (62) mounted on the carriage (61), with this core holder (62) carrying at least one primary core (64A) and one secondary core (64B) and being movable in rotation in relation to the carriage (61), in the demolding position of the latter, around an axis (R) of rotation that is parallel to the molding axis (M), between:
• A first alignment position in which the primary core (64A) extends in the alignment of the mold body (29) while the secondary core (64B) is offset in relation to the mold body (29), and
• A second alignment position in which the primary core (64A) and the secondary core (64B) are transposed;
• said unit (4) further comprising a pair of drawers (47), each carrying at least one neck half-ring (48) having an inner face (49) bearing the imprint of the neck (17) of a preform (2) and a tapered outer face (50), each drawer (47) being movable in relation to the mold holder (27) between a molding position in which the or each half-ring (48) is housed in a tapered reserve (35) formed projecting over the mold body (29), and a demolding position in which the or each half-ring (48) is separated from the tapered reserve (35);
• and
• said unit (4) further comprising, for each drawer (47), a return spring (59) mounted parallel to the guiding axis (G) and which drives the drawer (47) toward its demolding position, wherein each drawer (47) carries a roller (53), and the core holder (62) carries a support element (90) that, during the movement of the core holder (62) toward its molding position, pushes, by application against the roller (53), the drawer (47) back towards its molding position in opposition to the return spring (59).

Unit (4) for molding preforms (2) made of plastic material, with each preform (2) having a body (15) and a neck (17) in the extension of the body (15), with this unit (4) comprising:

• A frame (19),
• A mold holder (27) that is integral with the frame (19) and that carries at least one mold body (29) bearing the imprint of an outer face (33) of the body (15) of the preform (2), with this mold body (29) extending around a molding axis (M);
• A movable apparatus (60) including a carriage (61) and at least one oblong core (64A, 64B) bearing the imprint of an inner face (65) of the body (15) of the preform (2), with the carriage (61) being mounted to move in relation to the frame (19) between:
• A molding position in which the core (64A, 64B) is housed in the mold body (29), and
• A demolding position in which the core (64A, 64B) is axially separated from the mold body (29),
• wherein the movable apparatus (60) also comprises:
• A core holder (62) mounted on the carriage (61), with this core holder (62) carrying at least one primary core (64A) and one secondary core (64B) and being movable in rotation in relation to the carriage (61), in the demolding position of the latter, around an axis (R) of rotation that is parallel to the molding axis (M), between:
• A first alignment position in which the primary core (64A) extends in the alignment of the mold body (29) while the secondary core (64B) is offset in relation to the mold body (29), and
• A second alignment position in which the primary core (64A) and the secondary core (64B) are transposed;
• said unit (4) further comprising a device (111) for gripping molded preforms (2) extracted from the core holder (62), with this gripping device (111) comprising a first comb (119) carrying at least a first jaw (120) and a second comb (121) carrying at least a second jaw (122) defining, with the first jaw (120), a clamp (123) for gripping a preform (2), with the combs (119, 121) being mounted to move in relation to one another between a gripping position in which the jaws (120, 122) are drawn toward one another, and a release position in which the jaws (120, 122) are separated;
• and
• wherein the gripping device (111) comprises a return spring (127) that drives the combs (119, 121) toward the gripping position, the mold holder (27) carries a pair of cam grooves (128), and each comb (119, 121) carries a cam follower (131) that works with a cam groove (128) of which a narrow cross-section (130) places the combs (119, 121) in their release position in opposition to the return spring (127).

Unit (4) for molding preforms (2) made of plastic material, with each preform (2) having a body (15) and a neck (17) in the extension of the body (15), with this unit (4) comprising:

• A frame (19),
• A mold holder (27) that is integral with the frame (19) and that carries at least one mold body (29) bearing the imprint of an outer face (33) of the body (15) of the preform (2), with this mold body (29) extending around a molding axis (M);
• A movable apparatus (60) including a carriage (61) and at least one oblong core (64A, 64B) bearing the imprint of an inner face (65) of the body (15) of the preform (2), with the carriage (61) being mounted to move in relation to the frame (19) between:
• A molding position in which the core (64A, 64B) is housed in the mold body (29), and
• A demolding position in which the core (64A, 64B) is axially separated from the mold body (29),
• wherein the movable apparatus (60) also comprises:
• A core holder (62) mounted on the carriage (61), with this core holder (62) carrying at least one primary core (64A) and one secondary core (64B) and being movable in rotation in relation to the carriage (61), in the demolding position of the latter, around an axis (R) of rotation that is parallel to the molding axis (M), between:
• A first alignment position in which the primary core (64A) extends in the alignment of the mold body (29) while the secondary core (64B) is offset in relation to the mold body (29), and
• A second alignment position in which the primary core (64A) and the secondary core (64B) are transposed;
• said unit (4) further comprising a pair of drawers (47), each carrying at least one neck half-ring (48) having an inner face (49) bearing the imprint of the neck (17) of a preform (2) and a tapered outer face (50), each drawer (47) being movable in relation to the mold holder (27) between a molding position in which the or each half-ring (48) is housed in a tapered reserve (35) formed projecting over the mold body (29), and a demolding position in which the or each half-ring (48) is separated from the tapered reserve (35);
• and
• said unit (4) further comprising a device (92) for uncovering each molded preform (2) in a demolding position of the core holder (62).