Abstract: A vehicle trip odometer has a central shaft with both ends protruding for coupling of either end or both ends with other odometers. A total distance odometer likewise has both ends available for coupling to a trip odometer. Thus several arrangements of counter mechanisms are possible with a single design of trip and total odometers. Two trip odometers are serially driven by one end of the total odometer, or are each driven at opposite ends of the total odometer. A molded coupler connects shaft ends for joining adjacent odometers. Each shaft end has a flat for positive rotational drive of a coupler with a mating recess.

Abstract: A mechanical counter having number wheels rotatably mounted on a shaft with interleaved pinion carriers has a drive gear at one end fixed to the shaft and an end wheel rotatably mounted at the other end and retained by a washer press fit on the shaft. The end wheel has a cavity in its outboard side for receiving the washer, the cavity depth being greater than the washer thickness. The washer is installed by a press tool having a flat surface which engages both the washer and the outboard side of the end wheel to simultaneously advance the washer and seat the parts on the shaft. Then the washer and the bottom of the cavity are spaced by an amount providing the end play.