Short communicationInvestigation of a four-bar linkage for joining track carriages

- A crossing, overlapping 4-bar mechanism for joining tracked carriages is proposed.
- Modeling of linkage, carriage and train kinematics is outlined.
- Examples of parameter dependence are given.
- The ability of the concept to reduce chordal effect is demonstrated.

A linkage configuration, joining two carriages by two linkage bars, is configured to form a symmetric inverted crossover four-bar linkage. The linkage kinematics is described, and modelling of carriage train motion from a straight section to a uniformly curved section is performed, with the purpose of investigating carriage motion interdependence. Results indicate that, by appropriate selection of the geometric parameters of the carriage linkages, the effective (chord) length of each carriage, measured between endpoints of consecutive carriages, may be reduced upon entering a curved section. Hereby, the train polygon effect, causing unevenness of motion in open and closed carriage chains, may be significantly reduced on a local level.