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CRANKS AND CRANKSHAFTS | |
V. Ryan © 2004 - 2024 | |
Cranks have many uses and they can be found in some toys as part of a mechanism or in serious machinery such as car engines. Some cranks are attached to mechanisms that are difficult to turn or rotate. |
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The wind-up mechanism found inside an old gramophone is called a Spring-Driven Motor. The crank handle is wound up by hand. The energy is stored within the mechanism, in a coiled spring. To release the energy, the handle / spring is allowed to un-wind. This drives the internal mechanism of the gramophone, playing the music on the record. |
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The internal energy storage mechanism is seen below. | |
The crank acts like a lever, increasing mechanical advantage (the distance between the handle and the central shaft is increased - this makes it easier to turn). |
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Below is a good example of a crank shaft. When a shaft has two or more cranks it can be called a crank shaft. A typical example of a crank shaft can be found on small mechanical vehicles made for young children. As the child peddles the crank shaft rotates the wheels and the vehicle moves forward. |
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QUESTION: 1. Design a toy for a young child the operates with a crank or crank shaft. 2. Explain how a crank shaft on a pedal car makes it easier to move the car forwards. |
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EXAMPLE OF A MECHANICAL TOY BASED ON A CRANK | |
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