In reply to jimtitt: Guys, I know nothing about Patent Law or costs.
I was of the opinion that 20 years was about right and as the first application was Feb. 1993 looks pretty close to being up. Also, If fee's for maintenance of anything are in arrears, you probably forfeit some rights, otherwise why pay?
A simple Google search show its not been active since mid 90's. Just surprised some of the big rope companies are not all over it as they seem to be all chasing fancy coating that do this and that to make their product 'unique'.