| 摘要 |
Apparatus for supplying web material from reels thereof to a web-utilizing machine comprises a reel changer including a reel store, means for advancing reels in the store in succession to a reel-unwinding location, a web-transport system for feeding and guiding to the machine a web extending from a reel at that location, which system comprises at least one air mover, means for sensing the absence of web from a portion of the extent of the system and control means responsive to signals from said sensing means to activate air-supply to the air movers, whereby a leading end of a web length extending from a said reel is fed to the outlet end of the system. The web path of the transport system may include at least one curved portion defined by an air bearing. When the web is running through the transport system, air is supplied to the air bearing or bearings but not to the air mover or movers and, when a web end is being advanced to the utilizing machine, air is supplied to the air mover or movers, but not to the air bearing or bearings. A storage and advancing unit in the reel changer may comprise a hollow mandrel, means for advancing reels along the mandrel to the unreeling location and means operable at that location for coupling the reel to a rotatable shaft. There may be two reel changers associated with respective air movers which can be selectively brought into operative relation with an onward-going further air mover. |
