Image Number 2 for United States Patent #6161485.
A mobile carriage system includes a pair of end rails (12a, 12c) fixed to a support surface and one or more intermediate rails (12b) located parallel to and between the pair of end rails (12a, 12c). At least one carriage (10) is supported for movement on the end and intermediate rails (12a-c). The carriage (10) includes an elongated frame (17) that spans all of the rails. At least two drive units, each including a pair of wheels (23) and supporting the carriage on a different one of the rails are provided. The drive units are operatively connected to a drive shaft (35) which extends across a plurality of the rails. The drive shaft (35) and each of the drive units are coupled by a drive gear (33) on the shaft which has a substantially smaller diameter than the diameter of driven gears (29) on the units. An electric motor (41) is operatively connected to the drive shaft (35).