Insurance

 

"In an airplane the gyroscope is important because it can give positional and directional data to the pilot regardless of G-load or other forces. The gyroscope powers the artificial horizon and the heading indicator, two vital IFR instruments."
Seguro
Gyroscope
Lloyds of London
Psalm 127:1
[[A Song of degrees for Solomon.]] Except the LORD build the house, they labour in vain that build it: except the LORD keep the city, the watchman waketh but in vain.
Prov. 18:4
"The words of a man's mouth are as deep waters, and the wellspring of wisdom as a flowing brook."

Chateau d'Oex SWITZERLAND

 Elk, Selway Bitterroot Wilderness, Idaho

Chess: "Seguro" "Lloyds of London" "Gyroscope"
Gyroscope
A mechanical or optical device used to maintain orientation during motion. A mechanical gyroscope consists of a rapidly spinning wheel set in a framework that permits it to tilt freely in any direction or to rotate about any axis. The momentum of such a wheel causes it to retain its attitude when the framework is tilted. An optical gyroscope, laser or fibre, measures the interference pattern generated by two light beams, traveling in opposite directions within a mirrored ring or fibre loop, in order to detect very small changes in motion. Gyroscopes are used in compasses, in automatic pilots on ships and aircraft, in the steering mechanisms of torpedoes, in antiroll equipment on large ships, and in inertial guidance systems.

Background

The gyroscope is a familiar toy that is deceptively simple in appearance and introduces children to several mechanical principles, although they may not realize it. Something like a complex top made of precisely machined metal, the gyroscope is a spinning wheel that may be set within two or more circular frames, each oriented along a different line or axis. The framework can be tilted at any angle, and the wheel—as long as it is spinning—will maintain its position, or attitude.
But the gyroscope is not just a toy. It is a part of many scientific and transportation-related instruments. These include compasses, the mechanisms that steer torpedoes toward their targets, the equipment that keeps large ships such as aircraft carriers from rolling on the waves, automatic pilots on airplanes and ships, and the systems that guide missiles and spacecraft relative to Earth (that is, inertial guidance systems).
The gyroscope consists of a central wheel or rotor that is mounted in a framework of rings. The rings are properly called gimbals, or gimbal rings. Gimbals are devices that support a wheel or other structure but allow it to move freely. The rings themselves are supported on a spindle or axis at one end that, in turn, can be mounted on a base or inside an instrument. The property of the rotor axle to point toward its original orientation in space is called gyroscopic inertia; inertia is simply the property of a moving object to keep moving until it is stopped. Friction against the air eventually slows the gyroscope's wheel, so its momentum erodes away. The axle then begins to wobble. To maintain its inertia, a gyroscope must spin at a high speed, and its mass must be concentrated toward the rim of the wheel.

History

The gyroscope is a popular children's toy, so it is no surprise that its ancestor is the spinning top, one of the world's oldest toys. A single-frame gyroscope is sometimes called a gyrotop; conversely, a top is a frameless gyroscope. In the sixteenth through eighteenth centuries, scientists including Galileo (1564-1642), Christiaan Huygens (1629-1695), and Sir Isaac Newton (1642-1727) used toy tops to understand rotation and the laws of physics that explain it. In France during the 1800s, the scientist Jean-Bernard-Léon Foucault (1819-1868) studied experimental physics and proved Earth's rotation and explained its effect on the behavior of objects traveling on Earth's surface. In the 1850s, Foucault studied the motions of a rotor mounted in a gimbal frame and proved that the spinning wheel holds its original position, or orientation, in space despite Earth's rotation. Foucault named the rotor and gimbals the gyroscope from the Greek words gyros and skopien meaning "rotation" and "to view."
It was not until the early 1900s that inventors found a use for the gyroscope. Hermann Anschiutz-Kaempfe, a German engineer and inventor, recognized that the stable orientation of the gyroscope could be used in a gyrocompass. He developed the gyrocompass for use in a submersible for undersea exploration where normal navigation and orientation systems are impractical. In 1906, Otto Schlick tested a gyroscope equipped with a rapidly spinning rotor in the German torpedo boat See-bar. The sea caused the torpedo boat to roll 15° to each side, or 30° total; when his gyroscope was operated at full speed, the boat rolled less than 1° total.
In the United States, Elmer Ambrose Sperry (1860-1930)—an inventor noted for his achievements in developing electrical loco-motives and machinery transmissions—introduced a gyrocompass that was installed on the U.S. battleship Delaware in 1911. In 1909, he had developed the first automatic pilot, which uses the gyroscope's sense of direction to maintain the course of an airplane. The Anschiütz Company installed the first automatic pilot—based on a three-frame gyroscope—in a Danish passenger ship in 1916. In that year, the artificial horizon for aircraft was designed as well. The artificial horizon tells the pilot how the airplane is rolling (moving side to side) or pitching (moving front to rear) when the visible horizon vanishes in the clouds or other conditions.
Roll-reduction was needed for ships, too. The Sperry Company had introduced a gyrostabilizer that used a two-frame gyroscope in 1915. The roll of a ship on the ocean makes passengers seasick, causes cargo to shift and suffer damage, and induces stresses in the ship's hull. Sperry's gyrostabilizer was heavy, expensive, and occupied a lot of space on a ship. It was made obsolete in 1925 when the Japanese devised an underwater fin for stabilizing ships.
During the intense development of missile systems and flying bombs before and during World War II, two-frame gyroscopes were paired with three-frame instruments to correct roll and pitch motions and to provide automatic steering, respectively. The Germans used this combination on the V-1 flying bomb, the V-2 rocket, and a pilotless airplane. The V-2 is considered an early ballistic missile. Orbiting spacecraft use a small, gyroscope-stabilized platform for their navigation systems. This characteristic of gyroscopes to remain stable and define direction to a very high degree of accuracy has been applied to gunsights, bombsights, and the shipboard platforms that support guns and radar. Many of these mechanisms were greatly improved during World War II, and the inertial navigation systems that use gyroscopes for spacecraft were invented and perfected in the 1950s as space exploration became increasingly important.

Raw Materials

The materials used to manufacture a gyroscope can range from relatively simple to highly complex depending on the design and purpose of the gyroscope. Some are made more precisely than the finest watch. They may spin on tiny ball bearings, polished flecks of precious gemstones, or thin films of air or gas. Some operate entirely in a vacuum suspended by an electrical current so they touch nothing and no friction develops.
A gyroscope with an electrically powered motor and metal gimbals has four basic sets of components. These are the motor, the electrical components, electronic circuit cards for programmed operation, and the axle and gimbal rings. Most manufacturers purchase motors and electrical and electronic components from subcontractors. These may be stock items, or they may be manufactured to a set of specifications provided to the supplier by the gyroscope maker. Typically, gyroscope manufacturers machine their own gimbals and axles. Aluminum is a preferred metal because of its expansion and strength characteristics, but more sophisticated gyroscopes are made of titanium. Metal is purchased in bulk as bar stock and machined.

Design

Using the electrical and mechanical aspects of gyroscopic theory as their guides, engineers choose a wheel design for the gimbals and select metal stock appropriate for the design. The designs for many uses of gyroscopes are fairly standard; that is, redesign or design of a new line is a matter of adapting an existing design to a new use rather than creating a new product from the most basic beginning. Design does, however, involve observing the most fundamental engineering practices. Tolerances, clearances, and electronic applications are very precise. For example, design of the gimbal wheels and design of the machining for them has a very small tolerance for error; the cross section of a gimbal must be uniform throughout or the gyroscope will be out of balance.