Marman clamp

Typical Marman Clamp System

A Marman clamp is a type of heavy-duty band clamp; it allows two flat cylindrical interfaces to be simply clamped together with a ring clamp. It is sometimes also known as a "Marman ring".

Hose connectors

Aerospace pipe fittings, with flanges for Marman clamps.
Left is a semi-rigid bleed air duct from a jet engine
Right is semi-flexible fuel hose.

A common use for Marman clamps is as quick-disconnect connectors in flexible aircraft fuel lines.[1]

Spacecraft separation

Marman clamps are used extensively in spaceflight systems and are common mechanical load-transfer and clamping mechanisms for connecting the upper stage and the satellite payload of space vehicles,[2][3] for example, on the Cassini Plasma Spectrometer on the Cassini orbiter. They may also be used to join stages of a booster rocket.[2]

Early separation systems using Marman clamps used explosive bolts for release. These have problems of unpredictability, the need to contain debris and difficulties in testing them.[4] A more recent approach uses a screw thread. The tension of the clamp band itself is used to power the unscrewing of a central bolt, when released by a NASA Standard Initiator (NSI), a pyrotechnic pin puller.[5]

History

The Marman clamp was first produced by Herbert Marx, better known by his stage name of Zeppo Marx;[1][6] it was manufactured by his company, Marman Products from the 1930s.[7]

At the time it was designed to secure cargo during transport. The U.S. Military used it to transport the atomic bombs used at the end of the Second World War.

Marman clamps are found in many modern moving vehicles, though the screw band type clamp is becoming more popular.

The name is often incorrectly spelled "Marmon".

See also

References

  1. 1 2 D’Alto, Nick. "Oldies and Oddities: Zeppo's Gizmo". AIR & SPACE MAGAZINE. Retrieved 11 March 2014.
  2. 1 2 "Marman Clamp System Design Guidelines" (PDF). Guideline no. GD-ED-2214. NASA. Retrieved 2012-10-20.
  3. ↑ Shoghi, K.; Rao, H. V.; Barrans, Simon (2004). "Stress in V-section band clamps. Proceedings of the Institute of Mechanical Engineering Part C" (PDF). Journal of Mechanical Engineering Science. 3. 218: 251–261. doi:10.1243/095440604322900381. Retrieved 11 March 2014.
  4. ↑ Lazansky, Chuck (2012). "Refinement of a Low-Shock Separation System" (PDF). Proc. of the 41st Aerospace Mechanisms Symposium. Jet Propulsion Laboratory. p. 332. Retrieved 11 March 2014.
  5. ↑ Lazansky 2012, p. 333
  6. ↑ Chandler, Charlotte. Hello, I Must Be Going: Groucho And His Friends, page 182, ISBN 978-1-84739-104-9.
  7. ↑ Trevor Homer Born in the USA: The Book of American Origins,Skyhorse Publishing Inc., 2009 ISBN 1602397112 "Zeppo Marx"

External links

This article is issued from Wikipedia - version of the 7/4/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.