Multiple injection blow molding machine

Claim 2

An injection blow molding apparatus for automatically forming hollow articles of plastic material comprising a horizontally disposed rotatable and elevatable turret having six side faces, Distinct sets of hollow parison pins projecting outwardly from the side faces, 60* angularly spaced apart operating stations surrounding said turret with its parison pins and including a pair of opposing parison mold stations, a pair of opposing blow mold stations and a pair of opposing ejection stations, and means for indexing the turret first 120* in one direction and then in two cycles 60*in the opposite direction.

Claim 3

The invention of claim 1 wherein said indexing means includes a 120* cyclic rotary actuator operatively connected to the turret.

Claim 4

The invention of claim 2 wherein said turret has a supporting shaft assembly to which the actuator is connected, said shaft assembly having a radial arm, a stop pin engageable with the arm to limit the indexing movement of the turret in the opposite direction at one half of the 120* movement of the actuator and means for cyclically moving said stop pin out of braking engagement with the arm.

Claim 5

The invention of claim 1 wherein each of said ejection stations includes a mechanical means for positively stripping formed articles off the pins.

Claim 6

The invention of claim 4 wherein said mechanical means includes stripper fingers in which the pins are adapted to fit with the fingers engaging behind the formed articles on the pins and means for moving the fingers outwardly along the longitudinal axes of the pins to strip the articles off the pins.

Claim 7

The invention of claim 5 wherein each of the pins has an axial passage for the flow of pressure air to cool the articles prior to the stripping thereof from the pins and valve means controlling the flow of the cooling air through the pins.

Claim 8

The invention of claim 1 wherein each of said blow mold stations includes separable upper movable and lower fixed mold halves in which the parison pins with parisons formed from slugs at the parison mold stations thereon are adapted to be located, hydraulic rams carrying the upper mold halves and clamping the molds together about the pins, each of said pins having an axial bore providing an outer valve seat , a valve body seated in said seat, a valve stem slidably disposed in the pin bore and carrying the valve body, each pin having an inner end secured in the turret face, means provided in the turret and in the inner end of the pin for the admission of compressed air to the pin bore with the valve stem being smaller than the bore for the passage of the air to the outer valve end of the pin, springbiasing means acting on the inner end of the valve stem for seating the valve and means carried by the inner end of the valve stem and actuated by the air pressure for opening said valve to the pressure air which expands the parison in the blow mold to the shape and size of the blow mold.

Claim 9

The invention of claim 1 wherein each of the parison mold stations includes separable upper movable and lower fixed mold halves in which the parison pins are adapted to be located, means for injecting plastic melt into the parison molds and about the pins therein to form parisons on the pins, vertically oriented hydraulic rams carrying said movable halves of the parison molds, and raising and lowering said halves relative to clamping positions with the lower fixed halves and means mechanically linking said parison mold rams together for operation in unison.

Claim 10

The invention of claim 8 wherein said turret is supported by a turret shaft and means connecting the mechanical linkage means between the parison mold rams to the turret shafts so that the rams raise and lower the turret.

Claim 11

The invention of claim 9 wherein said last means causes the turret to move up one-half the opening distance of the parison mold halves so that the parison pins clear the parted parison and blow molds as the turret is indexed.

Claim 12

The invention of claim 1 wherein said apparatus includes a fixed horizontally disposed platen and a press plate fixed above and parallel with the platen and supported thereby, each of the parisOn mold stations including stationary lower parison mold halves fixed on the platen and movable upper mold halves, hydraulic rams vertically carried by the press plate and carrying said movable mold halves and adapted to clamp the mold halves together about the parison pins, means for injecting plastic melt into the closed parison molds about the parison pins therein, a shaft supporting the turret and rotatably and vertically slidably supported in the press plate parallel with and intermediate of the rams, means carried by the rams mechanically linking them together for operation in unison and means connecting said mechanical linkage means with the turret shaft so that the parison mold rams raise and lower the turret.

Claim 13

The invention of claim 11 wherein said mechanical linkage means between the rams includes vertical rack bars slidably mounted in the press plate with a rack bar adjacent and connected to each ram and disposed parallel therewith, an equalizing shaft rotatably mounted horizontally on the upper surface of the press plate and having pinions fixedly circumposed thereon and enmeshed with the rack bars for the rams, said turret shaft having a rack bar provided therefor and a pinion fixed on the equalizing shaft and enmeshed with the turret shaft rack bar, said latter pinion having one-half less the number of teeth than the ram rack bar pinions whereby the rams elevate the turret one-half the distance of the lifted upper mold halves so that the pins on the turret clear the parted mold halves.

Claim 14

The invention of claim 12 wherein said blow mold stations have portable mold halves with upper movable mold halves, said movable mold halves being carried by operating rams and said blow mold rams elevating the movable blow mold halves the same distance as the elevated parison mold halves with the parison pins on the elevated turret always being equidistant between the separation line between the parison mold halves.

Claim 15

An injection blow molding apparatus for automatically forming hollow articles of plastic material comprising a horizontally disposed rotatable and elevatable turret having side faces, distinct sets of parison pins carried by and projecting from the side faces, angularly spaced apart operating stations surrounding the turret with its parison pins, first means at one of the stations to mold parisons on the pins and including seperable mold halves, hydraulic rams clamping the mold halves together about the pins, means for injecting plastic melt into the closed mold halves about the pins therein, second means at another station to expand the parisons on the pins to articles of final shape and size and including separable blow mold halves and hydraulic rams clamping the blow mold halves about the pins therein, said turret being connected to a source of compressed air and said parison pins being hollow and in communication with the pressure air for the passage of the pressure air through the pins to expand the parisons, said pins having valves controlling the passage of pressure air therethrough, third means at a third station for positively mechanically removing formed articles from the parison pins, and means controlled by the rams for the parison molds to maintain the parison pins always equidistant between the halves of parison molds, said third means including mechanical stripper fringers in which the parison pins with the blown articles thereon are adapted to fit with the fingers engaging behind the formed articles on the pins and means for moving the fingers outwardly along the longitudinal axes of the pins to strip the articles off the pins.

Claim 16

An injection blow molding apparatus for automatically forming hollow articles of plastic material comprising a horizontally disposed rotatable and elevatable turret having side faces, distinct sets of parison pins carried by and projecting from the side faces, angularly spaced apart operating stations surrounding the turret with its parison pins, first means at one of the stations to mold parisons on the pins and including seperable mold halves, hydraulic rams clamping the mold halves together about the pins, means for injecting plastic melt into the closed mold halves about the pins therein, second means at another station to expand the parisons on the pins to articles of final shape and size and including separable blow mold halves and hydraulic rams clamping the blow mold halves about the pins therein, said turret being connected to a source of compressed air and said parison pins being hollow and in communication with the pressure air for the passage of the pressure air through the pins to expand the parisons, said pins having valves controlling the passage of pressure air therethrough, third means at a third station for positively mechanically removing formed articles from the parison pins, and means controlled by the rams for the parison molds to maintain the parison pins always equidistant between the halves of parison molds, said third means including mechanical stripper fringers in which the parison pins with the blown articles thereon are adapted to fit with the fingers engaging behind the formed articles on the pins and means for moving the fingers outwardly along the longitudinal axes of the pins to strip the articles off the pins.

Claim 17

An injection blow molding apparatus for automatically forming hollow articles of plastic material comprising a horizontally disposed rotatable and elevatable turret having side faces, distinct sets of parison pins carried by and projecting from the side faces, angularly spaced apart operating stations surrounding the turret with its parison pins, first means at one of the stations to mold parisons on the pins and iNcluding separable mold halves, hydraulic rams clamping the mold halves together about the pins, means for injecting plastic melt into the closed mold halves about the pins therein, second means at another station to expand the parisons on the pins to articles of final shape and size and including separable blow mold halves and hydraulic rams clamping the blow mold halves about the pins therein, said turret being connected to a source of compressed air and said parison pins being hollow and in communication with the pressure air for the passage of the pressure air through the pins to expand the parisons, said pins having valves controlling the passage of pressure air therethrough, third means at a third station for positively mechanically removing formed articles from the parison pins, and means controlled by the rams for the parison molds to maintain the parison pins always equidistant between the halves of parison molds, and means for first indexing the turret an angular distance in one direction in one full movement and for then indexing it in the other direction in a step by step movement of increments one half the total movement in the first direction.

Claim 18

An injection blow molding apparatus for automatically forming hollow articles of plastic material comprising a horizontally disposed rotatable and elevatable turret having side faces, distinct sets of parison pins carried by and projecting from the side faces, angularly spaced apart operating stations surrounding the turret with its parison pins, first means at one of the stations to mold parisons on the pins and iNcluding separable mold halves, hydraulic rams clamping the mold halves together about the pins, means for injecting plastic melt into the closed mold halves about the pins therein, second means at another station to expand the parisons on the pins to articles of final shape and size and including separable blow mold halves and hydraulic rams clamping the blow mold halves about the pins therein, said turret being connected to a source of compressed air and said parison pins being hollow and in communication with the pressure air for the passage of the pressure air through the pins to expand the parisons, said pins having valves controlling the passage of pressure air therethrough, third means at a third station for positively mechanically removing formed articles from the parison pins, and means controlled by the rams for the parison molds to maintain the parison pins always equidistant between the halves of parison molds, and means for first indexing the turret an angular distance in one direction in one full movement and for then indexing it in the other direction in a step by step movement of increments one half the total movement in the first direction.

Claim 19

In an injection blow molding apparatus for automatically forming hollow articles of plastic material, a rotatable turret having side faces carrying distinct sets of parison pins, 60* angularly spaced apart operating stations surrounding the turret and including a pair of opposing parison mold stations, a pair of opposing blow mold stations and a pair of opposing ejection stations and means to index the turret first 120* in one direction and then in two cycles of 60* in the opposite direction.

Claim 20

In an injection blow molding apparatus for automatically forming hollow articles of plastic material, a rotatable turret having side faces carrying distinct sets of parison pins, 60* angularly spaced apart operating stations surrounding the turret and including a pair of opposing parison mold stations, a pair of opposing blow mold stations and a pair of opposing ejection stations and means to index the turret first 120* in one direction and then in two cycles of 60* in the opposite direction.

Claim 21

In an injection blow molding apparatus for automatically forming hollow articles of plastic material, a rotatable and elevatable turret carrying parison pins, a parison mold station including a separable parison mold having a fixed bottom mold half and a movable top mold half, a hydraulic ram carrying said movable mold half and clamping the mold halves about the parison pins therein, and means connecting said ram to the turret so that the turret is elevated by the ram as the movable mold half is raised with the turret being raised one half the distance of the movable mold half, an ejection station including mechanical fingers in which the pins carrying formed articles are adapted to fit with the fingers engaging behind the articles and means for moving the fingers outwardly along the longitudinal axes of the pins to strip the articles off the pins.

Claim 22

In an injection blow molding apparatus for automatically forming hollow articles of plastic material, a rotatable and elevatable turret carrying parison pins, a parison mold station including a separable parison mold having a fixed bottom mold half and a movable top mold half, a hydraulic ram carrying said movable mold half and clamping the mold halves about the parison pins therein, and means connecting said ram to the turret so that the turret is elevated by the ram as the movable mold half is raised with the turret being raised one half the distance of the movable mold half, an ejection station including mechanical fingers in which the pins carrying formed articles are adapted to fit with the fingers engaging behind the articles and means for moving the fingers outwardly along the longitudinal axes of the pins to strip the articles off the pins.