Molded thermoplastic parking block with slideably interengaged members
US5028463A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 1989 |
| Grant date | Jul 2, 1991 |
| Priority date | — |
| Expiry date | Jul 25, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31855
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The present invention is directed to elongate rigid thermoplastic articles that are molded from thermoplastic material and which maintain their shape even at length-to-width ratios (i.e. aspect ratios) ranging from about 4:1 to about 15:1 or greater. The inventive elongate rigid thermoplastic articles comprise molded thermoplastic material having disposed interiorly therein along their longitudinal extent a system (e.g. a pair) of slideably interengaged members. Preferred slideably interengaged members comprise hollow pipes that are sleeved for slideable interengagement. In the molding of elongate rigid thermoplastic articles in accordance with the present invention, the interiorly disposed slideably interengaged members are acted upon by the shrinkage of the cooling thermoplastic material resulting in the members sliding into closer interengagement. Distortion of the cooled elongate thermoplastic articles is substantially suppressed thereby.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.