suspension system including a lighting device

A lamp suspension system for telescopically adjusting a lamp suspension assembly by means of flat wires comprises a take-up means for winding or unwinding the wires. A sensor lever (232) which is swingably mounted above and biassed towards the take-up means has pawls (236, 237) that are engaged with a ratchet wheel (208) fixed to the take-up means when the sensor lever (232) is swung toward the take-up means. A pulley (239) at an end of the sensor lever (232) engages the wires and a limit switch (242) detects any swinging motion of the sensor lever in the direction away from the take-up means to arrest rotation thereof. An unwinding sensor lever (252) swingably mounted below, and biassed towards the take-up means has a roller which contacts an outer edge of the take-up means and also has a pawl (258) engageable with the ratchet wheel (208) when the roller is engaged in a recess (217) at the outer edge of the take up means, once a slider member has unblocked the recess.