| 摘要 |
A device (10) for metering discrete lengths of filament utilized in a flexible filament vegetation cutting device is disclosed. The line metering device (10) is preferably used in flexible filament lawn mowers. An electric motor (28) rotatively drives a drive shaft (32) about its axis. A driving mechanism, preferably a spool (36) is coupled to the drive shaft (32) for rotation therewith whenever the drive shaft (32) is rotated. A driven mechanism, preferably a guide drum (84), is selectively coupled for rotation to the driving mechanism (36). The spool (36) has the flexible filament (66) wound about it and is coupled to one of the driven and driving mechanisms (84, 32) for rotation therewith. The metering mechanism includes a device (172) for rapidly decelerating the rotating drive shaft (32) and driving mechanism (36), together with a device (54) for disengaging the guide drum mechanism (84) from the spool (36) during the rapid deceleration whereby the guide drum (84) is free to rotate a discrete amount relative to the spool (36). In this manner a length of filament (66) is metered from the spool (36). |
