§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
US3833332A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for forming containers of thermoplastic material

Assignee: OI Glass Inc
•
Filing: 1972-11-17
•
Granted: 1974-09-03
•
Expires: 1992-11-17
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Method and apparatus for reforming thermoplastic preforms or parisons of a nestable configuration into non-nestable containers which are adapted to receive threaded metallic or plastic closures. Each preform is inserted over the end of a complementally shaped heating mandrel to heat the preform to an elevated temperature at which it is sufficiently soft to permit it to be reformed into a different configuration by blow molding. The preform is retained in place during the heating step by a vacuum applied to the inner surface of the preform through the mandrel. Prior to or during the heating step, the mandrel, with the preform in place, is inserted into the open top of a mold, the inner surface of which is, in a major lower portion, configured in the shape of a jar or other container of nonnestable configuration. The upper minor portion of the mold is configured in the shape of an internally threaded cylinder. After the preform reaches a suitably high temperature, the vacuum to the inside surface thereof is terminated and air or other gas pressure is applied thereto through the mandrel to blow or expand the preform to correspond to the interior of the mold, thereby to provide a container with an externally threaded upper neck portion which is adapted to receive a threaded closure. Good contact between the preform heating mandrel and the mold is obtained by providing the preform with a short externally extending continuous flange at its larger open end which serves as a gripping surface to be tightly engaged between the structure carrying the mandrel and mold structure. To avoid the need for a trimming operation, the lateral extent of this flange must be less than the lateral extent of the threaded portion of the neck of the finished container, to avoid interference with the associated closure to be applied thereto. Such a flange, if left in place, will serve to stiffen the mouth of the finished container.

Inventors

  • 👤 R Amberg
  • 👤 S Amberg

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 13:40
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/071; B29C2949/00; B29C2949/07; B29C2949/073; B29C2949/0733; B29C2949/076; B29C2949/0761; B29C2949/0762; B29C2949/0768; B29C2949/0769; B29C2949/077; B29C2949/0771; B29C2949/078; B29C2949/20; B29C2949/22; B29C2949/24; B29C2949/26; B29C2949/28

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 270 words
Apparatus for reforming a thermoplastic preform of a nestable shape into a container which is of a different shape and which has an externally threaded neck-portion, said preform having a generally frusto-conically shaped side wall, a bottom wall at the smaller end of the side-wall and integral therewith, and an outwardly extending flange surrounding the larger end of the sidewall and integral therewith, said apparatus comprising, in combination; ported wall means defining a mandrel whose external surface corresponds in size and shape to the internal surfaces of the sidewall and bottom wall of the preform, said mandrel receiving said preform and being in substantially continuous conductive heat transfer relationship therewith; means for heating the preform when it is on the mandrel; an open-top portable mold cavity receiving the mandrel with the preform thereon, said mold cavity having an internal surface spaced outwardly from and shaped differently than the external surface of the preform, a minor portion of said internal surface being an integral part of the mold defining said mold cavity and disposed adjacent to the larger end of the mandrel and being shaped in the form of a cylinder with an outwardly projecting helical groove therein, the maximum inside diameter of the groove being greater than the outside diameter of the flange of the preform; and means for applying pressure to the inside of the preform after it is at its reforming temperature to reform the preform into the shape of said container including an externally threaded neck portion whose external shape corresponds to the internal shape of the minor portion of the internal surface of the mold cavity.
Claim 2
Dependent Claim 270 words
Apparatus for reforming a thermoplastic preform of a nestable shape into a container which is of a different shape and which has an externally threaded neck-portion, said preform having a generally frusto-conically shaped side wall, a bottom wall at the smaller end of the side-wall and integral therewith, and an outwardly extending flange surrounding the larger end of the sidewall and integral therewith, said apparatus comprising, in combination; ported wall means defining a mandrel whose external surface corresponds in size and shape to the internal surfaces of the sidewall and bottom wall of the preform, said mandrel receiving said preform and being in substantially continuous conductive heat transfer relationship therewith; means for heating the preform when it is on the mandrel; an open-top portable mold cavity receiving the mandrel with the preform thereon, said mold cavity having an internal surface spaced outwardly from and shaped differently than the external surface of the preform, a minor portion of said internal surface being an integral part of the mold defining said mold cavity and disposed adjacent to the larger end of the mandrel and being shaped in the form of a cylinder with an outwardly projecting helical groove therein, the maximum inside diameter of the groove being greater than the outside diameter of the flange of the preform; and means for applying pressure to the inside of the preform after it is at its reforming temperature to reform the preform into the shape of said container including an externally threaded neck portion whose external shape corresponds to the internal shape of the minor portion of the internal surface of the mold cavity.
Claim 3
Dependent Claim 108 words
Apparatus according to claim 1 and further comprising means for applying vacuum to the interior of the mandrel while the preform is being heated to maintain the preform in position on the mandrel; and means to discontinue the application of vacuum to the preform before pressure is applied to the inside of the heated preform. 3. Apparatus according to claim 1 wherein the wall means defining the mandrel is formed of a thermally conductive material, and wherein the means for heating the preform comprises means away from the preform for heating the mandrel, whereby the preform will be heated by heat conducted through the mandrel from such means.
Claim 4
Dependent Claim 57 words
Apparatus according to claim 1 wherein the wall means defining the mandrel comprises an offset portion adjacent a central portion of the bottom wall of the preform, and wherein the bottom wall of the preform is offset to lie in contact with the offset portion of the wall means to accurately register the preform on the mandrel.
Claim 5
Dependent Claim 33 words
Apparatus according to claim 1 and further comprising mandrel supporting structure adapted to firmly press the flange of the preform against the outside of the mold cavity during the reforming of the preform.
Claim 6
Dependent Claim 45 words
Apparatus according to claim 5 wherein the flange contacting portion of the mandrel supporting structure is formed of a material of a resilient nature and with good thermal insulating properties to prevent the flange from being softened by the heatiNg effects of the heating means.

References Cited (Backward Citations)

GB1060249A Cited
US3770860A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-09-02 1978-03-04 1978-09-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-09-02 1982-03-04 1982-09-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-09-02 1986-03-04 1986-09-03 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag