Sprocket
From Wikipedia, the free encyclopedia
- This article is about a gear or wheel with metal teeth. For the television comedy skit, see Sprockets (television).
Do: Sprocket diameter
Dp: Pitch diameter
A sprocket is a gear or wheel with metal teeth that meshes with a chain or track. Sprockets are used in bicycles, motorcycles, cars, tanks, and other machinery.
In the case of bicycle chains by varying the size (and therefore, the tooth count) of the sprockets on each side of the chain, modifying the overall gear ratio of the chain drive is possible. A 10-speed bicycle, by providing two different-sized driving sprockets and five different-sized driven sprockets, allows up to ten different gear ratios. The resulting lower gear ratios make the bike easier to pedal up hills while the higher gear ratios make the bike faster to pedal on flat roads. In a similar way, manually changing the sprockets on a motorcycle can change the characteristics of acceleration and top speed by modifying the final drive gear ratio.
In the case of tanks the engine-driven toothed-wheel transmitting motion to the tracks is known as the drive sprocket and may be positioned at the front or back of the vehicle, or in some cases, both.
Sprockets are used in the film transport mechanisms of movie projectors and movie cameras. In this case, the sprocket wheels engage film perforations in the film stock.
[edit] Sprockets in culture
- The fictional character George Jetson works for the Spacely Sprocket Company, a company that presumably is involved in the production of space-age sprockets. What these sprockets drive is left to the imagination of the viewer.
- In Viewtiful Joe and Viewtiful Joe: Red Hot Rumble, the producer of Movie Land is named Coordinator Sprocket.
- In the Fraggle Rock TV series Doc's dog is named Sprocket.
- Sprockets was made famous on Saturday Night Live.
