Tweel

The Tweel (a portmanteau of tire and wheel) is an airless tire design concept developed by the French tire company Michelin. Its significant advantage over pneumatic tires is that the Tweel does not use a bladder full of compressed air, and therefore it cannot burst, leak pressure, or become flat. Instead, the Tweel assembly's inner hub connects to flexible polyurethane spokes which are used to support an outer rim and these engineered compliant components assume the shock-absorbing role provided by the compressed air in a traditional tire.

Design

The Tweel consists of a band of conventional tire rubber with molded tread, a shear beam just below the tread that creates a compliant contact patch, a series of energy-absorbing polyurethane spokes, and an integral inner rim structure. Both the shear beam and the polyurethane spokes can be designed to provide a calibrated directional stiffness in order that design engineers are able to control both how the Tweel handles and how it handles loads. The inner hub structure may be either rigid or compliant, depending on the application requirements, and as such may contain a matrix of deformable plastic structures that flex under load and subsequently return to their original shape. By varying the thickness and size of the spokes, Michelin can manipulate the design elements to engineer a wide array of ride and handling qualities. The tread can be as specialized as any of today's tires and is replaceable when worn.

Tweel (A Martian Odyssey)

Tweel (also referred to as a "Tweerl", the exact pronunciation of the word is said to be impossible for humans) is a fictional extraterrestrial from the planet Mars, featured in two short stories by Stanley G. Weinbaum. The alien was featured in A Martian Odyssey, first published in 1934, and Valley of Dreams four months later. Weinbaum died of lung cancer soon after, and a third installment in the series never saw fruition. Tweel remains one of the most recognised aliens in early science fiction, and is said to be an inspiration for aliens in the works of Isaac Asimov and Arthur C. Clarke.

Asimov described Tweel as being the first creation in science fiction to fulfill John W. Campbell's request for "(...)a creature that thinks as well as a man, or better than a man, but not like a man."

Appearance

Tweel's appearance is described as follows:

The Martian wasn't a bird, really. It wasn't even bird-like, except at first glance. It had a beak, alright, and a few feathery appendages, but the beak wasn't really a beak. It was somewhat flexible; I could see the tip bend from side to side; it was almost like a cross between a beak and a trunk. It had four toed feet, and four fingered things--hands, you'd have to call them, a little roundish body, and a long neck ending in a tiny head--and that beak.

Tweel (disambiguation)

Tweel may refer to: