from The Century Dictionary.
- noun In a vehicle, a compound spring consisting of a rectangular arrangement of four arched springs, each made up of long, thin, curved steel plates of regularly diminishing lengths bolted together.
Sorry, no etymologies found.
The carriage was a platform-spring wagon, with a man and woman in the front seat, and in the rear a couple of alert young fellows sat holding rifles in their hands and eyeing the plain for game.
Then the bearers lifted the coffin and slipped it into the platform-spring wagon, which was backed up to the door.