Injection system for ganged injection molds

Claim 2

An injection arrangement for injection-molding machines and the like comprising a mold assembly including a plurality of relatively displaceable mold-carrying plates and respective mold member mounted on said plates, said mold members defining at least two molds having at least two spaced-apart parallel separation planes in closed positions of said molds, at least some of said plates being displaceable relatively in a direction perpendicular to said planes; a distributor nozzle having an axis extending perpendicular to said planes and communicating with said molds in the closed position thereof, said planes being spaced along the axis of the nozzle, said distributor nozzle being formed with a main feed passage along said axis for an injectable material adapted to charge said molds, said nozzle extending through at least some of said plates, and respective auxiliary feed passages branching from said main feed passage at least at two axially spaced locations each associated with one of said planes and leading to the respective molds, said auxiliary feed passages being of substantially equal length.

Claim 3

The arrangement defined in claim 1, further comprising respective sprue bushings on said plates communicating with the respective molds and said auxiliary feed passages, said sprue bushings being formed with conical seats, said distributor nozzle being formed with frustoconical surfaces respectively engaging said seats upon relative axial displacement of said Plates and said distributor nozzle.

Claim 4

The arrangement defined in claim 2, further comprising abutment means engageable with said distributor nozzle in an open position of said molds for relieving the axial pressure of said surfaces on said seats.

Claim 5

An injection arrangement for injection-molding machines and the like comprising a mold assembly including a plurality of relatively displaceable mold-carrying plates and respective mold members mounted on said plates, said mold members defining at least two molds having parallel separation planes in closed positions of said molds, at least some of said plates being displaceable relatively in a direction perpendicular to said planes; a distributor nozzle, extending generally transversely to said planes and communicating with said molds in the closed position thereof, said distributor nozzle being formed with a main feed passage for an injectable material adapted to charge said molds, and respective auxiliary feed passages branching from said main feed passage and leading to the respective molds, said auxiliary feed passages being of substantially equal length; respective sprue bushings on said plates communicating with the respective molds and said auxiliary feed passages, said sprue bushings being formed with conical seats, said distributor nozzle being formed with frustoconical surfaces respectively engaging said seats upon relative axial displacement of said plates and said distributor nozzle, each of said mold members being provided with a bore coaxial with said distributor member and receiving a respective one of said bushings, said bushings each having a large-diameter step received with axial clearance between a pair of juxtaposed surfaces on the respective plate permitting lost motion in the axial direction of each of said sprue bushings relative to the respective plate.

Claim 6

An injection arrangement for injection-molding machines and the like comprising a mold assembly including a plurality of relatively displaceable mold-carrying plates and respective mold members mounted on said plates, said mold members defining at least two molds having parallel separation planes in closed positions of said molds, at least some of said plates being displaceable relatively in a direction perpendicular to said planes; a distributor nozzle, extending generally transversely to said planes and communicating with said molds in the closed position thereof, said distributor nozzle being formed with a main feed passage for an injectable material adapted to charge said molds, and respective auxiliary feed passages branching from said main feed passage and leading to the respective molds, said auxiliary feed passages being of substantially equal length; respective sprue bushings on said plates communicating with the respective molds and said auxiliary feed passages, said sprue bushings being formed with conical seats, said distributor nozzle being formed with frustoconical surfaces respectively engaging said seats upon relative axial displacement of said plates and said distributor nozzle, each of said mold members being provided with a bore coaxial with said distributor member and receiving a respective one of said bushings, said bushings each having a large-diameter step received with axial clearance between a pair of juxtaposed surfaces on the respective plate permitting lost motion in the axial direction of each of said sprue bushings relative to the respective plate.

Claim 7

The arrangement defined in claim 4 wherein sprue bushings of the mold members of each mold have juxtaposed faces mutually and sealingly engaging along the respective separating plane in a closed position of said plates, said faces being formed with grooves defining sprue channels communicating between the respective mold and the distributor nozzle.

Claim 8

The arrangement defined in claim 5 wherein said material is fed in one axial direction into said distributor nozzle at one end thereof, said sprue bushings including a bushing most distal from said one end, said arrangement further comprising a hydraulically actuated counterpressure element urging said most-distal sprue bushing into engagement with said distributor nozzle upon closure of the molds.

Claim 9

The arrangement defined in claim 6, further comprising force-storing means interposed between said counterpressure element and said most distal sprue bushing.

Claim 10

The arrangement defined in claim 7, further comprising a hydraulic cylinder receiving said counterpressure element, said counterpressure element constituting a piston hydraulically displaceable in said cylinder, a control cylinder communicating with the first-mentioned cylinder, a control piston displaceable in said control cylinder for displacing fluid into said first-mentioned cylinder, and means connecting said control piston to at least one of said plates for actuation of said control piston upon displacement of said plates toward one another.

Claim 11

The arrangement defined in claim 5 wherein the lost motion of the sprue bushings furthest from said end of said distributor nozzle is less than the lost motion of the other sprue bushings.

Claim 12

The arrangement defined in claim 9 wherein the lost motion of the pair of sprue bushings most removed from said end of said distributor nozzle is defined by a pair of outer surfaces, the spacing of the outer surfaces being less than the spacing of the portions of the plates engageable therewith.

Claim 13

The arrangement defined in claim 5, further comprising heating means along said distributor nozzle ahead of the branching point of said auxiliary feed passages, said auxiliary fEed passages being defined at least in part by an insert of a material of high thermal conductivity received within said distributor nozzle.

Claim 14

An injection arrangement for injection-molding machines and the like comprising a mold assembly including a plurality of relatively displaceable mold-carrying plates and respective mold members mounted on said plates, said mold members defining at least two molds having parallel separation planes in closed positions of said molds, at least some of said plates being displaceable relatively in a direction perpendicular to said planes; and a distributor nozzle extending generally transversely to said planes and communicating with said molds in the closed position thereof, said distributor nozzle being formed with a main feed passage for an injectable material adapted to charge said molds, and respective auxiliary feed passages branching from said main feed passage and leading to the respective molds, said auxiliary feed passages being of substantially equal length, said auxiliary feed passages each including a transverse passage at the end of said main feed passage, a pair of oppositely directed passages parallel to said main feed passage, and discharge passages at the ends of said parallel passages, all of said passages being formed directly in said distributor nozzle.

Claim 15

An injection arrangement for injection-molding machines and the like comprising a mold assembly including a plurality of relatively displaceable mold-carrying plates and respective mold members mounted on said plates, said mold members defining at least two molds having parallel separation planes in closed positions of said molds, at least some of said plates being displaceable relatively in a direction perpendicular to said planes; and a distributor nozzle extending generally transversely to said planes and communicating with said molds in the closed position thereof, said distributor nozzle being formed with a main feed passage for an injectable material adapted to charge said molds, and respective auxiliary feed passages branching from said main feed passage and leading to the respective molds, said auxiliary feed passages being of substantially equal length, said auxiliary feed passages each including a transverse passage at the end of said main feed passage, a pair of oppositely directed passages parallel to said main feed passage, and discharge passages at the ends of said parallel passages, all of said passages being formed directly in said distributor nozzle.

Claim 16

The arrangement defined in claim 12 wherein said main feed passage extends centrally through said distributor nozzle and said parallel passages are located outwardly thereof.

Claim 17

The arrangement defined in claim 12 wherein said main feed passage terminates substantially midway between said molds.

Claim 18

The arrangement defined in claim 12 wherein said distributor nozzle comprises a tube extending axially through at least some of said plates, an inner duct extending spacedly within said tube and defining a clearance therearound forming said parallel passages, said central duct terminating short of the end of said tube and defining said main feed passage within said duct, and a deflecting member being received with clearance within said tube between the end thereof and said duct.

Claim 19

The arrangement defined in claim 15 wherein said deflecting member is composed of a material of high thermal conductivity.

Claim 20

The arrangement defined in claim 15 wherein said duct is composed of a material of high thermal conductivity.