A brake band is a device that is often included in a number of braking system designs. The band itself is usually a flat metal band that is smooth on the topside, but rougher on the underside. Typically, the brake band is round, creating a loop that can be tightened or loosened around a shaft. The friction created when the belt is tightened helps to slow and eventually stop the rotation of that shaft.
A brake band is often used as part of the gearset equipment that is attached to a transmission. In this application, it is not unusual for the band to be composed of steel. The underside is lined with some type of friction material, and the band is positioned around the drum of the equipment. When the gears pull the band, the rotating action of the drum is slowed and stopped.
Along with the band and the drum, there are several other elements that compose brake band equipment. An anchor is usually used to attach one end of the band to the casing of the transmission. This particular element aids in adjusting the amount of clearance that exists between the drum and the brake band proper. An element known as a servo piston is used to apply pressure to the band, either tightening or loosening the pressure of the band around the drum. This helps to preserve the integrity of that pressure that is applied to the drum and helps to manage the function of the brake band. In some designs, additional hydraulic equipment is utilized to increase the efficiency of the pressure exerted on the drum and the band.
This same basic idea is used in other applications. A chainsaw brake band makes it possible to control the speed of the saw teeth, quickly moving from a maximum speed to a complete stop. Tractors used in commercial farming often make use of brake band equipment as part of the overall engine and transmission design. Even a child’s go-kart can makes use of this relatively simplistic design for controlling the speed of the device and bringing it to a complete stop.
In many automotive designs, the brake band is considered an essential part of the emergency braking system. This means that if problems develop with the main brake system, the operator of the vehicle can apply the emergency brake, which utilizes the band to slow the rotation of the front or back wheels, gradually bringing the vehicle to a stop. While an emergency braking system generally does not respond as rapidly as a main system, this backup braking apparatus increases the potential of stopping the forward movement of the vehicle before there is any injury to the driver or any other occupants of the car or truck.