KNOB WITH DIFFERENT GEAR RATIOS

摘要

A knob adjustment device particularly for adjusting the temperature in valve units for water-heating apparatus. The device comprises a geared transmission interposed between the knob and an operating member of the valve unit in order to transmit a rotary movement to the member about its own axis as a result of a rotation of the knob. The geared transmission includes a reduction mechanism with a variable transmission ratio such that, for a first angular portion and a second angular portion of the rotation of the knob, the member is rotated with respective different transmission ratios (T₁,T₂).