Rotary assembly for molten plastic

Claim 2

Apparatus according to claim 1 wherein the plug and housing are cooperatively constructed to expose a surface of said plug having a conduit inlet opening for direct engagement by a supply member from the extruder.

Claim 3

Apparatus according to claim 3 wherein said surface is located on a side wall of said plug, the conduit of said plug extending from said inlet opening through an angle to the outlet end of said plug.

Claim 4

Apparatus according to claim 4 wherein said housing defines a lateral passage with which said inlet opening aligns when said plug is in place, said lateral passage sized to enable said supply member from the extruder to extend through said housing into sealing engagement with said sidewall of said plug, to supply molten plastic directly thereto.

Claim 5

Apparatus according to claim 5 wherein said housing defines an alignment surface adapted to be engaged by a side portion of said plug to align the outlet of said plug with said rotary section, said plug shaped to have a loose fit within said housing and to be pressed against said alignment surface by said supply member thereby enabling ready removal of said plug when said supply member is withdrawn.

Claim 6

Apparatus constructed to deliver molten plastic from an extruder to a rotary die orifice, said apparatus including a stationary conduit section communicating through a transition region to a rotary conduit section, a stationary supporting structure remote from the stationary-corotary conduit transition region supporting said rotary section in an aligned, slightly spaced-apart relation to said stationary section, thereby forming a clearance slot between the relatively moving sections, an annular transition member-retaining formation formed in the adjacent portion of at least one of the pair of said aligned section, said formation together with an opposed surface of the other aligned section forming a groove of axial dimension greater than said clearance space, said groove open to the conduit, and an annular transition and sealing member disposed within and substantially filling said groove and extending across said clearance space, the inner surface of said transition member forming a portion of the conduit and substantially smoothly aligned with the adjacent conduit surfaces of said stationary and rotary sections.

Claim 7

Apparatus according to claim 7 wherein the transition member is comprised of a low-friction plastic and said clearance slot being narrow to resist cold-flow of said transition member through said clearance slot under operating conditions.

Claim 8

Apparatus according to claim 7 wherein said sTationary conduit section comprises an outer housing, and a removable conduit-forming plug disposed within said outer housing, the end of said plug engaging one side of said transition and sealing member.

Claim 9

Apparatus according to claim 7 wherein said rotary section is mounted on an adjustable support constructed to vary both the spacing of said clearance space and the size of said transition member-retaining formation.

Claim 10

Apparatus constructed to deliver molten plastic from an extruder to a rotary die orifice, said apparatus including a stationary conduit section and a rotary conduit section, said rotary section including a hollow spindle, a face seal of rigid material disposed between said spindle and an end surface of said stationary conduit section, a stationary bearing housing, annular bearings surrounding said spindle and disposed within said housing, a retainer means secured to said bearing housing and resiliently engaged against the outer stationary race of said bearings, a projection from said spindle engaging the inner race of said bearings, so that axial force applied by said retainer can be transferred through said bearings to said spindle, thus applying force to said outer bearing race whereby said spindle bears with substantial force against said face seal member, preloading said face seal member.

Claim 11

The apparatus of claim 11 wherein said retainer means comprises at least one conical, annular spring member having an outer diameter corresponding substantially to the diameter of the outer race of said bearing and a retainer cap engaged upon the inner portion of said spring forcing the outer portion thereof against the outer race of said bearing.

Claim 12

The apparatus of claim 11 wherein said face seal of rigid material is defined by a sintered layer of bronze particles, said layer impregnated with a mixture of low friction fluorocarbon plastic and lead powder.