Ear plug as well as a method and apparatus for the production thereof
US4498469A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 20, 1982 |
| Grant date | Feb 12, 1985 |
| Priority date | — |
| Expiry date | May 20, 2002 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61F11/08
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The ear plug (40) includes an elongate body with a rounded tip portion and of an elastic material enveloped by a deep-drawn sheath (41) of thin flexible plastics film material. Rearwardly the plug preferably has a neck portion from which the sheath projects in the form of a stiffer collar or flange. Production of the ear plug includes deep-drawing a thermoplastic film or foil into a sheath with desired thickness distribution, and filling the sheath with elastic material (53). Filling may take place simultaneously with deep-drawing, the body of elastic material constituting a die for deep-drawing in a forming hole (45), or after the deep-drawing. In the latter case, an elastic die body is used to advantage, the shape of which generally corresponds to that of the finished plug, for deep-drawing in a forming hole suited to the die body.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.