Patent ID: 7581288

Claim:
A suction tube for a vacuum cleaner comprising: an outer pipe; an inner pipe received in said outer pipe, the inner pipe having an outer surface and an inner surface and being provided axially with a row of detent holes, each of which penetrates through the wall of the inner pipe from said outer surface to said inner surface; a locking device having a detent pin for positioning said inner pipe with respect to said outer pipe; a guiding bush attached to said outer pipe, a first guiding member disposed at the guiding bush; a second guiding member attached to said inner pipe, being engageable and slidable with said the first guiding member so that said inner pipe and said outer pipe can move axially with respect to each other; a separate inner liner layer secured at a fixed position to the inner surface of said inner pipe, the inner liner layer isolating vacuum of the inner pipe from the detent holes; wherein said detent pin of said locking device is inserted into one of said detent holes when said locking device is in a locking state, and disengages with the detent hole when said locking device is in an unlocking state; and said inner liner layer is an inner liner tube having an outer surface and an inner surface and which is provided at its outer surface with a groove extending axially along said inner liner tube and facing said detent holes.