Polymeric foam earplug
First Claim
1. A roll-down type earplug construction comprising a resilient polymeric foam body the cellular volume of said foam body being gas-filled, said body comprising a nose section and, coextensive therewith, a tail section,said nose section being composed of a slow recovery, viscoelastic, polymeric foam and being of a size and shape adapted to be compressed, inserted into the human ear canal and there allowed to expand and obturate the ear canal, said nose section having a room temperature recovery time from 60 percent compression to 40 percent compression thereof at least 1 second and an equilibrium pressure at 40 percent compression thereof of from 0.2 to 1.3 p.s.i.,said tail section being composed of a relatively faster recover, more elastic, polymeric foam than that of said nose section, said tail section having a room temperature recovery time from 60 percent compression to 40 percent compression thereof of no greater than 50 percent of the recovery time of said nose section and no greater than 5 seconds.
3 Assignments
0 Petitions
Accused Products
Abstract
Disclosed herein are hearing protective earplug constructions of the roll-down type. In one aspect the constructions employ means to limit the depth of insertion of the earplug into the ear canal and to facilitate proper insertion thereof. In another aspect, the constructions employ polymeric foam bodies adapted to be compressed, inserted into the ear canal and there allowed to expand to obturate the ear canal and whose recovery time is markedly and inversely temperature dependent.
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Citations
23 Claims
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1. A roll-down type earplug construction comprising a resilient polymeric foam body the cellular volume of said foam body being gas-filled, said body comprising a nose section and, coextensive therewith, a tail section,
said nose section being composed of a slow recovery, viscoelastic, polymeric foam and being of a size and shape adapted to be compressed, inserted into the human ear canal and there allowed to expand and obturate the ear canal, said nose section having a room temperature recovery time from 60 percent compression to 40 percent compression thereof at least 1 second and an equilibrium pressure at 40 percent compression thereof of from 0.2 to 1.3 p.s.i., said tail section being composed of a relatively faster recover, more elastic, polymeric foam than that of said nose section, said tail section having a room temperature recovery time from 60 percent compression to 40 percent compression thereof of no greater than 50 percent of the recovery time of said nose section and no greater than 5 seconds.
Specification