US 6,605,247 B2Granted

Blow molding process

AssigneePhillips Petroleum Company

InventorsDale A. Zellers, Jimmie L. Dean, Thomas O. Morton, Matthew P. Clark, Don L. Peters

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Abstract

The invention relates to blow molding of an article having an inwardly projecting hollow boss with a closed end. A portion of a molten parison conforms to the shape of a fixed pin projecting from the face of a mold part to thereby form the hollow boss. The invention includes an apparatus comprising a reciprocable sleeve slidably received within the mold part over the pin. It has been found that by blow molding the parison with the sleeve initially extended with its end substantially flush with the end of the pin, followed by retracting the sleeve to a retracted position after a predetermined delay time, a boss with a thicker end results. Consequently, the boss end has greater structural integrity, and thus minimizes or eliminates the possibility of penetration and/or cracking of the boss end when a screw is threadedly received in the hollow boss.

Claims8

Dependent claims

A blow molding process comprising:

(a) providing (i) a mold part having a mold face and an opening extending through the mold part which is hereafter denoted as a mold opening, the mold opening having an end at the mold face, (ii) a sleeve having an end and slidably received in the mold opening, and (iii) a pin having an end and fixedly positioned relative to the mold part so as to extend through the sleeve and beyond the mold opening end with the pin end spaced therefrom outside of the mold opening;
(b) positioning the sleeve in an extended position with the sleeve end substantially flush with the pin end;
(c) initiating blow molding of a molten parison with respect to the mold face and sleeve in its extended position;
and
(d) retracting the sleeve to a retracted position, in which the pin extends beyond the sleeve end with the pin end spaced therefrom outside of the sleeve, at a predetermined delay time after (c), at which time the parison is still sufficiently molten to allow a portion of the parison to form around that portion of the pin extending beyond the sleeve end.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/206,114Filed 29 Jul 2002 · division
Priority: 24 Sep 1999
Published: US 2002/0195749 A126 Dec 2002
Granted: 12 Aug 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

B29C 49/4802
Moulds: with means for locally compressing part of the parison in the main blowing cavity
B29C 49/04
Combined blow-moulding and manufacture of the preform or the parison: extrusion blow-moulding
B29C 2049/2017
Of articles having inserts or reinforcements ; Handling of inserts or reinforcements: outside the article
B29C 2049/206
Inserts characterised by the material or type: being constructed in such a way that the joining between the insert and the preform or parison is…