Figure 4
The schematic of the novel caster required the track length and key angle to determine the design conditions. \(r_{1}\) and \(r_{2}\) represent the radius of caster main and sub-wheel. \(\theta _{1}\) is the composition angle of the caster. \(\theta _{2}\) is the angle of the force generated by the contact of the caster main wheel. \(l_{1}\) to \(l_{4}\) are the part lengths. \(W_{f}\) represents the vertical load applied from the main wheel.
