Johnson bar is the term for several different hand-operated levers used in vehicles. Their distinguishing feature is a positive latch, typically spring-loaded, to hold the lever in a selected position, capable of being operated with one hand. Some Johnson bars have a fully ratcheting mechanism, some just a series of detents, and others yet simply engaged and disengaged positions.
A common example is the Johnson bar-controlled parking brake found on many trucks and buses.
In North America, the "Johnson bar" is the term for a lever which controls a steam locomotive's valve gear. In other countries, the term "reversing lever" is used. [1] [2]
The forward/reverse lever on Caterpillar tractors is also called a Johnson bar.
Some light general aviation aircraft (including Piper Cherokees, Beech Musketeers, and some early model Cessnas – such as the Cessna 140) - use Johnson bars to actuate flaps and wheel brakes. The Cessna 162 Skycatcher uses a Johnson bar for flap operation. A small number of older aircraft (including the Mooney M-18, some older M20s and some Progressive Aerodyne SeaReys) also have landing gear actuated by Johnson bars. The Boeing 707/720 aircraft had a Johnson bar for manually extending the nose landing gear, in case the normal gear extension failed.[ citation needed ]
A machine is a physical system using power to apply forces and control movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to natural biological macromolecules, such as molecular machines. Machines can be driven by animals and people, by natural forces such as wind and water, and by chemical, thermal, or electrical power, and include a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement. They can also include computers and sensors that monitor performance and plan movement, often called mechanical systems.
A bicycle brake reduces the speed of a bicycle or prevents it from moving. The three main types are: rim brakes, disc brakes, and drum brakes.
Landing is the last part of a flight, where a flying animal, aircraft, or spacecraft returns to the ground. When the flying object returns to water, the process is called alighting, although it is commonly called "landing", "touchdown" or "splashdown" as well. A normal aircraft flight would include several parts of flight including taxi, takeoff, climb, cruise, descent and landing.
The Cessna 152 is an American two-seat, fixed-tricycle-gear, general aviation airplane, used primarily for flight training and personal use. It was based on the earlier Cessna 150 incorporating a number of minor design changes and a slightly more powerful engine with a longer time between overhaul.
An automatic transmission is a multi-speed transmission used in motor vehicles that does not require any input from the driver to change forward gears under normal driving conditions.
Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called alighting gear by some manufacturers, such as the Glenn L. Martin Company. For aircraft, Stinton makes the terminology distinction undercarriage (British) = landing gear (US).
The valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle. It can also serve as a reversing gear. It is sometimes referred to as the "motion".
The Yakovlev Yak-52 is a Soviet primary trainer aircraft which first flew in 1976. It was produced in Romania from 1977 to 1998 by Aerostar, as Iak-52, which gained manufacturing rights under agreement within the former COMECON socialist trade organisation. The Yak-52 was designed as an aerobatic trainer for students in the Soviet DOSAAF training organisation, which trained civilian sport pilots and military pilots. Currently the Yak-52 is used in the Fédération Aéronautique Internationale (FAI) World Aerobatic Yak 52 Competition, a popular powered aircraft one-design World Aerobatic Championship.
A conventional fixed-wing aircraft flight control system (AFCS) consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. Aircraft engine controls are also considered as flight controls as they change speed.
The Cessna 150 is a two-seat tricycle gear general aviation airplane that was designed for flight training, touring and personal use. In 1977, it was succeeded in production by the Cessna 152, a minor modification to the original design.
Main components found on a typical steam locomotive include:
Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail. The term taildragger is also used, although John Brandon of Recreational Aircraft Australia argues it should apply only to those aircraft with a tailskid rather than a wheel.
The Walschaerts valve gear is a type of valve gear used to regulate the flow of steam to the pistons in steam locomotives, invented by Belgian railway engineer Egide Walschaerts in 1844. The gear is sometimes named without the final "s", since it was incorrectly patented under that name. It was extensively used in steam locomotives from the late 19th century until the end of the steam era.
In road vehicles, the parking brake, also known as a handbrake or emergency brake (e-brake), is a mechanism used to keep the vehicle securely motionless when parked. Parking brakes often consist of a pulling mechanism attached to a cable which is connected to two wheel brakes. In most vehicles, the parking brake operates only on the rear wheels, which have reduced traction while braking. The mechanism may be a hand-operated lever, a straight pull handle located near the steering column, or a foot-operated pedal located with the other pedals.
A reverser handle is an operating control for a railroad locomotive that is used to determine the direction of travel. The reverser usually has three positions: forward, reverse, and neutral.
The Tecnam P2002 Sierra is a two-seat, low-wing, light aircraft designed and constructed by the Italian aircraft manufacturer Tecnam. Introduced during the early 2000s, the aircraft quickly became a staple of the company's product lineup, comprising 70 percent of its available production capacity during some years.
A motorcycle transmission is a transmission created specifically for motorcycle applications. They may also be found in use on other light vehicles such as motor tricycles and quadbikes, go-karts, offroad buggies, auto rickshaws, mowers, and other utility vehicles, microcars, and even some superlight racing cars.
On a steam locomotive, the reversing gear is used to control the direction of travel of the locomotive. It also adjusts the cutoff of the steam locomotive.
Gab valve gear was an early form of valve gear used on steam engines. Its simplest form allowed an engine to be stopped and started. A double form, mostly used on steam locomotives, allowed easy reversing.
The Central South African Railways Rack 4-6-4RT of 1905 was a South African steam locomotive from the pre-Union era in Transvaal Colony.