The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 09, 1986
Filed:
Jun. 01, 1984
Alec R Carruthers, Nr. Westbury, GB;
ALH Systems Limited, Westbury, GB;
Abstract
In an iris-stop arrangement for stopping-off a duct the secondary bag has a contact length with the duct of at least 0.7 times its diameter. The apparatus is such that the point where the inflation neck of the bag meets the remainder of the bag can adopt a position not substantially in front of the secondary bag support member. Thus the bag has improved functional grip on the duct and does not suffer severe flexing at the neck when it moves back to rest against the support member. Preferably the portion of the bag which contacts the duct in use is a single layer of fabric thick while the ends of the bag, which have to withstand the bag inflation pressure unsupported, are two layers thick. In this way the bag can have good performance characteristics while only needing a relatively small insertion hole in the side of the duct.