Roll cage
From Wikipedia, the free encyclopedia
- For the computer game, see Rollcage.
- Roll bar redirects here. For the suspension component called a roll bar, see sway bar.
A roll cage is a specially constructed frame built in or around the cab of a vehicle to protect the occupants from being injured in an accident, particularly in the event of a roll-over. Roll cages extend in front of the driver, next to the A-pillar, to provide as much high-speed protection as possible in a coupé. This is compared to the protection provided in open wheel racing, where a solid shell encases the majority of the driver's body as well as a rollover hoop that extends over the driver's helmet. A roll cage can also do a great deal to stiffen the chassis, which is desirable in racing applications.
A roll bar is a single bar behind the driver that provides moderate roll-over protection. A targa top is a body style that integrates an externally-visible roll bar that a semi-convertible top attaches to. Convertibles have particular concerns for roll-over protection. In most modern convertibles a strong windscreen frame acts as a roll bar.
Roll hoops are essentially two roll bars, one behind the driver and one behind the passenger. Sometimes just a single roll hoop behind the driver is used. Sometimes they are integrated into the design of the body.
A newer form of rollover protect is deployable roll hoops that are normally hidden within the body of a car. When sensors detect an imminent rollover, the roll hoops quickly extend and lock in place. Cars that have a deployable rollover protection system include the Peugeot 307 CC [1], Mercedes-Benz SL 500, and Jaguar XK [2]. See also RollOver Protection System.
