A unique, hard-to-find, pivoting cleat that
allows the line to run freely until it is pulled out of alignment.
Frequently used for spinnaker halyard pump-up systems.
The halyard exits the mast, goes through a
cam cleat and usually a fairlead. Then there is some space before the
halyard runs through the pump cleat. On the line in this space there is
a trap handle on a block, which you hold to pump. The tail of the
halyard then continues through a fairlead or cheek block and is taken up
by shock cord. As you pump the handle, the pump-cleat goes out of
alignment holding the tail and causing the halyard to take up through
the cam cleat. As you lower the handle, the pump cleat aligns again
allowing the shock cord to take up the tail through the pump cleat,
readying the system for another pump if needed.