Wire Advancer

It is a combination of two oneway linear clutches
The green clutch (in the right) linearly reciprocates (its motion source is not shown) and makes the wire move to the right only.
The grey clutch (on the left) is stationary and prevents the wire from moving to the left.
Red springs always force the balls towards the wire.
Key factor:
tg(A/2) must be less than f1 and f2
A: vertex angle of the inner cone that are in contact with the balls.
f1, f2: coefficients of friction between the balls and the inner cones, between the balls and the wire respectively.
This mechanism was seen in paperclip making machines.