Heavyweight wheel handling trolley has lengthwise member adjusted by rack and pinion mechanism with torsion spring that breaks under excessive stress

摘要

The trolley consists of a chassis that runs on casters and is equipped with rolling cylinders on cross-members, uprights with an optional retaining strap, and a lengthwise member that can be adjusted to suit wheels of different sizes. The lengthwise member is in two sections adjusted by means of a rack (91) and pinion (93) mechanism and a coaxial torsion spring (94) that locks the pinion in a set position and is subjected to a stress applied to the chassis cross-members by a wheel. The torsion spring has projecting ends (98, 99) that engage with stops (101, 102) in the pinion and has a limited resistance to breaking so that it ruptures under an excessive stress that would otherwise damage the trolley.