I chose to create this floor lamp in brass from an online catalog due to its technical appearance and functionality. Apparently, the lamp head itself is raised or lowered via a cord which spans the three pulleys and to an adjustable cord length clamp which sets the range of adjustment. The configuration with the lower pulley utilizes a 2:1 velocity ratio known as 'Mechanical Advantage' which makes the effort to move the lamp head at 1 half the amount of effort as a directly hung lamp cord.
The 3d model was created using Blender 2.79b with 'cycles' render engine. Further reading on velocity ratios can be found at http://www.technologystudent.com/gears1/pulle12.htm