obienick;c-66057 wroteI may not have had the most technical terminology in that post. My apologies if it was confusing.
The bottom of that apparatus in your pic is a sheave (note the rubber liner) that goes inside the terminal. The haul rope moves from the motor driving the bullwheel in the bottom terminal. The haul rope spinning drives that sheave.
Attached at the top of that sheave is a pulley (note the 3 grooves) to drive all moving equipment in the upper/return terminal: the tire contour to decelerate the chairs, turn them around at slow speed, and accelerate them again back up to line speed to return down the hill. The tires are all connected to one another with pulleys and differential diameters of the pulleys allow for slowing and speeding the chairs.
This apparatus is to guarantee that everything is in synch if the lift is operated at a different speed. Just having a motor in the top terminal to drive everything could mean that the tires are too slow or too fast … or even not start or stop with the lift.
PTO = power take off
Thanks for the clarification. I knew what the sheave was. I didn't know what the other half was, and PTO was a new acronym to me.
