Apparatus for pulling loads along as vertical cable, which apparatus includes: two plates constituting a support member; two shafts mounted for free rotation relative to the support member; two pulleys each mounted for rotation on a respective shaft and each having a groove for receiving the cable, the pulleys being positioned so that the grooves lie in a common plane and the cable can be wrapped in an S-shaped configuration around the pulleys; two toothed wheels each fixed to a respective shaft and in toothed engagement with one another so as to rotate in mutually opposite directions, the toothed wheels being disposed within the support member and the pulleys being located outside of the support member and being supported by the shafts in a cantilever manner; and two detent members mounted to each act on a respective toothed wheel in a manner such that as one detent member acts to rotate its respective toothed wheel the other detent member acts to prevent reverse movement of its respective toothed wheel. Two levers are each mounted for pivotal movement about a respective one of the shafts and a crank for coordinating the movements of the first and second levers has two opposed ends each pivotally connected to a respective lever. Each detent member is coupled to a respective lever and cooperates with a respective toothed wheel to rotate the respective toothed wheel in response to pivotal movement of a respective lever in a given direction.
