| 摘要 |
A guide for contactless support of a running web as the latter changes directions. The guide is formed as a drum-like member having an arcuately curved surface which can be variable as to the length of its arc depending on the degree of turn or change of direction desired for the running web. A pair of circumferentially spaced air nozzles extend along the length of the drum-like member and transversely across the web and pressurized air is fed through the nozzles so as to form a pneumatic cushion between the web and the arcuate surface of the drum-like member to thereby float the web in its turning direction over the drum-like member and without contact therewith. The invention includes a pair of air nozzles, one extending along each side edge of the running web and located outside the width of the web and which not only retard or eliminate leakage of air from the supporting air cushion out from under the longitudinal edges of the web, but also act on the web to eliminate side drift or lateral tracking instability of the web. |
