Method for blow molding a container having a concave bottom
US4036926A · kind A · utility
96Cited by
7References
1Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 16, 1975 |
| Grant date | Jul 19, 1977 |
| Priority date | — |
| Expiry date | Jun 16, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2049/548
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of making a concave bottom on a blown thermoplastic container. A blowable pre-form is initially expanded against a composite mold surface defined by the end faces of a plurality of concentric tubes surrounding a central actuating rod. The rod and the tubes are initially telescopically positioned to define a composite concave surface, so that a first convex bottom is blown. Subsequently, the rod and tubes are actuated telescopically to progressively invert the convex bottom to a concave shape. The end faces of the tubes may be grooved to define reinforcing ribs in the concave bottom wall, if desired.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.