| 摘要 |
A filter changing device comprising a rotatory structure having first and second passage means therethrough in nonparallel, nonintersecting relationship, each of the passage means being adapted releasably to hold a filter, and means for supporting the rotatory structure for rotation about an axis from a first position in which the respective ends of the first passage means are at predetermined points to a second position in which the respective ends of the second passage means instead of the first passage means are located at the same predetermined points.
|
