| 摘要 |
A method for opening an opening ( 10 ) using an elastic plug ( 2, 2 ') whose outside diameter in a static state (r<SUB>L</SUB>), is larger than diameter (r<SUB>p</SUB>) of opening ( 10 ), and which plug has a cavity ( 12 ) at its end. An extending device ( 4, 4 ') is inserted into plug cavity ( 12 ) so that the plug is tightly pressed around extending device ( 4, 4 '). Plug ( 2, 2 ') is extended by inserting extending element ( 20 ) of extending device ( 4, 4 ') into plug cavity ( 12 ) so deeply that outside diameter (r<SUB>V</SUB>) of plug ( 2, 2 ') is equal to, or smaller than, diameter (r<SUB>p</SUB>) of opening ( 10 ). The extended plug is inserted into opening ( 10 ), and its extension is reduced such that plug ( 2, 2 ') closes opening ( 10 ) and adheres to it so tightly that extending device ( 4, 4 ') is detachable from plug ( 2, 2 '). A method for opening the opening ( 10 ) when closed by plug ( 2, 2 ') is also disclosed. |
