Patent · US Expired

Earmuff having sealing ring including liquid and foam plastic layers

US4674134A · kind A · utility

103Cited by
3References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 25, 1986
Grant dateJun 23, 1987
Priority date
Expiry dateMar 25, 2006

Classification

  • Technology area (CPC A)Human Necessities
  • CPC primaryA61F11/14
  • WIPO fieldMedical technology
  • WIPO sectorInstruments

Abstract

An earmuff (10) has a sealing ring (20) with an outer liquid layer (38) and a foamed plastics layer (36) thereinunder. The liquid layer is arranged as a separate, annular, sheath-equipped liquid ring (38) the sheath (40) of which can move freely relative the sheath (30,32) of the sealing ring (20).

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.