| 摘要 |
A web sensor for sensing the edge of a web in a feather like action is disclosed which includes a feeler (10) carried by rotary disk (12) which fits into a pair of housing sections (20, 24) and is coupled to the housing by means of weighted balls (32, 34, 36). The weighted balls are carried in a circumferential slot (42) with a clearance (44). The weighted balls extend into arcuate slots (38, 40) in the housing sections and dampen rapid oscillations in the pendular motion of feeler (10). Turning of rotary disk (12) interrupts a pair of energy beams which may be light (50A, 52A) or an air jet (124, 126). Depending upon which energy beam is interrupted, the web is moved accordingly until feeler (10) resumes its neutral position.
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