Upper Winch Tensioner and Winch Tension Indicator
The Upper winch tensioner consists of two assemblies. The winch tensioner (Figure
8) is a spring-loaded roller
of a similar design
to that used
on the lower winch.
Again, the tensioner maintains a positive pressure on the cable to help prevent the
cable from becoming slack on the drum.
The upper winch cable tension indicator assembly (Figure 2. 9) consists of a roller,
pivot arm and limit switch which are used to stop excessive cable being paid out. The
roller sits on top of the upper winch cable, when the cable goes slack such that it sits
on top of the launch beam the roller is lowered and trips the limit switch. Once the
limit switch has tripped, the winch is prevented from paying out any more cable. It
can only pay in cable so that tension is re-established.
The limit switch is monitored via the firmware in the launcher main control enclosure,
and is only functional in a HIGH BANK build. It is only in HIGH BANK that the top
winch is driven proportionally via the chest pack joystick. In all other instances, the
upper winch is either applying back tension, which is trying to pull in cable or the
cable, is being pulled off the upper winch.