A Marman clamp is a type of heavy-duty band clamp; it allows two cylindrical objects to be clamped together end-to-end with a ring clamp. It is sometimes also known as a "Marman ring". It consists of a circular strap with an interior V-shaped groove. Tension is applied to the strap with a threaded bolt and nuts connecting to the ends of the strap. As the circumferential tension increases, the V-groove wedges over flanges on the circular parts to be assembled, providing the axial force that holds the ends of the two cylinders together. The Marman clamp is an alternative to a bolted flange connection which would be heavier and require more labor to connect. Another variety uses a flat strap, used where systems carry low pressure or to hold a cylindrical object in position.

Hose connectors

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

Spacecraft separation

Marman clamps are used extensively in spaceflight systems and are common mechanical load-transfer and clamping mechanisms for connecting the

upper stage A multistage rocket or step rocket is a launch vehicle that uses two or more rocket ''stages'', each of which contains its own Rocket engine, engines and Rocket propellant, propellant. A ''tandem'' or ''serial'' stage is mounted on top of anoth ...

and the

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

payload of

space Space is a three-dimensional continuum containing positions and directions. In classical physics, physical space is often conceived in three linear dimensions. Modern physicists usually consider it, with time, to be part of a boundless ...

vehicles A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered vehicles (e.g. bicycles, tricycles, velomobiles), animal-powered tr ...

, for example, on the Cassini Plasma Spectrometer on the Cassini orbiter. They may also be used to join stages of a booster rocket. 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. 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 pyrotechnic pin puller triggered by a set of redundant NASA Standard Initiators (NSIs).

History

The Marman clamp was first produced by Herbert Marx, better known by his stage name

Zeppo Marx Herbert Manfred "Zeppo" Marx (February 25, 1901 – November 30, 1979) was an American comedic actor. He was the youngest, and last survivor, of the five Marx Brothers. He appeared in the first five Marx Brothers feature films from 1929 to 1933 ...

; it was manufactured by his and his business partner A. Dale Herman's company, Marman Products. British-born James Thomas King, who had developed a career in aeronautical engineering and aircraft manufacture in Canada before moving to the United States, applied for patents on a hose clamp in mid-1941, and they were granted early the next year. In July 1943, King granted Marman exclusive rights to make the clamp and sell it internationally. In 1947, King filed a suit against Marman, claiming breach of contract and calling for a financial accounting. The parties settled the action out of court and signed a new contract, in April 1948, by which time King had become a founding director of the helicopter cargo airline, Los Angeles Airways, Inc. At the time the Marman clamp was designed to secure cargo during transport. The U.S. Military also used Marman clamps to transport the

atomic bomb A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear expl ...

s 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.

References

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External links

The CAPS Launch Latch
Clamps (tool) Plumbing Spaceflight technology

Hose connectors

Spacecraft separation

History

See also

References

External links