counterweight

Information about counterweight

''For the Outer Limits episode, see Counterweight (The Outer Limits)
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Simple Crane


A counterweight is an equivalent counterbalancing weight that balances a load.[1]

Uses

A counterweight is often used in traction lifts (elevators), cranes and funfair rides. In these applications, the expected load multiplied by the distance that that load will be spaced from the central support (called the "tipping point") must be equal to the counterweight's mass times its distance from the tipping point in order to prevent over-balancing either side. This distance times mass is called the load moment.[2]

Counterweights in action

Trebuchet

Main article: Trebuchet


There are five major components of a trebuchet: beam, counterweight, frame, guide chute, and sling. After the counterweight drops from a platform on the frame, gravity pulls the counterweight and pivots the beam. Without the counterweight, the beam could not complete the arc that allows the sling to accurately release the projectile.[3][4]

Crankshaft

Main article: Crankshaft


A counterweight is also used in many rotating systems to reduce vibrations due to imbalances in the rotating assembly. A typical example is counterweights on crankshafts in piston engines.[5]

Desk lamp

Some balanced arm lamps work with a counterweight to keep the arm and lamp in the desired position.

Elevator

Main article: Elevator
In traction (non-hydraulic) elevators, a heavy counterweight counterbalances the load of the elevator car, so the motor only has to lift the difference between the car load and the counterweight load. The counterweight also increases the ascending acceleration force and decreases the descending acceleration force to reduce the amount of horsepower needed by the motor. The elevator car and the counterweights both have rollers attached to them to prevent irregular movement and provide a smoother ride for the passengers.[6]

Metronome

Main article: Metronome


A wind-up mechanical metronome has an adjustable weight and spring mechanism that allows the speed to be adjusted by placement of the weight on the spindle. The tempo speed is decreased by moving the the weight to a higher spindle marking or increased by moving it to a lower marking.[7]

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Concrete counterweights on a tower crane

Tower Cranes

Main article: Crane (machine)


The tower crane (see picture) is a modern form of balance crane that is fixed to the ground. A horizontal boom is balanced asymmetrically across the top of the tower. The long arm carries the lifting gear.[8] The short arm is called the machinery arm; this holds the motors and electronics to operate the crane, as well as the concrete counterweights.[9]

References

1. ^ The Free Dictionary by Farlex: Definition of Counterweight. Retrieved on 7 April 2007.
(Note: Free Dictionary cites: The American Heritage® Dictionary of the English Language, Fourth Edition copyright ©2000 by Houghton Mifflin Company. Updated in 2003. Published by Houghton Mifflin Company.)
2. ^ Basic Crane Design principles. E-Crane™ International (2002).
3. ^ How a Trebuchet Catapult Works. Retrieved on 7 April 2007.
4. ^ How does a catapult work? (1 April 2000). Retrieved on 7 April 2007.
5. ^ Wan, Mark (2000). AutoZine Technical School: Engine Smoothness. Retrieved on 7 April 2007.
6. ^ Bellis, Mary. The History of the Elevator. Retrieved on 7 April 2007.
7. ^ Metronome. Wikipedia. Accessed 7 April 2007.
8. ^ Crane (machine). Wikipedia. Accessed 7 April 2007.
9. ^ Brain, Marshall. How Tower Cranes Work. Retrieved on 7 April 2007.
Episode no. Season 2
Episode 14
Guest stars Michael Constantine
Jacqueline Scott
Written by Milton Krims (teleplay)
Jerry Sohl (story)
Directed by Paul Stanley
Photographed by Kenneth Peach

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elevator or lift is a transport device used to move goods or people vertically. Languages other than English may have loanwords based on either elevator (e.g. Japanese) or lift (e.g. many European languages, Cantonese).
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elevator or lift is a transport device used to move goods or people vertically. Languages other than English may have loanwords based on either elevator (e.g. Japanese) or lift (e.g. many European languages, Cantonese).
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crane is a mechanical lifting device equipped with a winder, wire ropes and sheaves that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability
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funfair or simply fair (e.g. "county fair", "state fair") is a small to medium sized traveling fair primarily composed of amusement rides. Larger fairs or the permanent fairs of cities and seaside resorts may be called a fairground
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Principle of Moments redirects here. For the Robert Plant album, see The Principle of Moments. See also Moment (mathematics) for a more abstract concept of moments that evolved from this concept of physics.

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trebuchet is a medieval siege engine, a weapon employed either to smash masonry walls or to throw projectiles over them. It is sometimes called a "counterweight trebuchet" in order to distinguish it from an earlier weapon that has come to be called the "traction trebuchet.
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crankshaft, sometimes casually abbreviated to crank, is the part of an engine which translates reciprocating linear piston motion into rotation. It typically connects to a flywheel, to reduce the pulsation characteristic of the four-stroke cycle, and sometimes a torsional
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crankshaft, sometimes casually abbreviated to crank, is the part of an engine which translates reciprocating linear piston motion into rotation. It typically connects to a flywheel, to reduce the pulsation characteristic of the four-stroke cycle, and sometimes a torsional
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A reciprocating engine, also often known as a piston engine, is a heat engine that uses one or more pistons to convert pressure into a rotating motion. This article describes the common features of all types.
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balanced-arm lamp is a lamp with an adjustable folding arm which is constructed so that the force due to gravity is always counteracted, regardless of the position of the arms of the lamp.
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elevator or lift is a transport device used to move goods or people vertically. Languages other than English may have loanwords based on either elevator (e.g. Japanese) or lift (e.g. many European languages, Cantonese).
..... Click the link for more information.
elevator or lift is a transport device used to move goods or people vertically. Languages other than English may have loanwords based on either elevator (e.g. Japanese) or lift (e.g. many European languages, Cantonese).
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electric motor converts electrical energy into mechanical energy. The reverse process, that of converting mechanical energy into electrical energy, is accomplished by a generator or dynamo.
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Horsepower (hp) is the name of several non-metric units of power. The most occurring conversion of horsepower to watt goes 1 horsepower = 745.7 watts. In scientific discourse, the term "horsepower" is seen as inferior and is rarely used because of its various definitions and
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metronome is any device that produces a regulated audible and/or visual pulse, usually used to establish a steady beat, or tempo, measured in beats-per-minute (BPM) for the performance of musical compositions.
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crane is a mechanical lifting device equipped with a winder, wire ropes and sheaves that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability
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metronome is any device that produces a regulated audible and/or visual pulse, usually used to establish a steady beat, or tempo, measured in beats-per-minute (BPM) for the performance of musical compositions.
..... Click the link for more information.
crane is a mechanical lifting device equipped with a winder, wire ropes and sheaves that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability
..... Click the link for more information.

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