With cylindrical drum: progressive traction, one balances the load or the tool, one positions his height with the choice, one draws on the load or on the tool to carry out the slackened work, once load or the tool, they return to their initial position.
With conical drum: constant traction on all the race, the load or the tool remain in balance with the desired position.
With pawl: allows to block the rope lathe by lathe or with the wanted position, to free to draw downwards.
Without pawl: the load is balanced or the tool with the position desired, after use the load or the tool takes again its initial position.