Bus Door Service Brake Interlock System

An auxiliary line is positioned between a source of pressure and the foot valve assembly and includes a valve and a low pressure.

Bus door service brake interlock system.

A door safety system meeting the criteria in this specification will prevent the bus from moving or stop it if already moving. The virginia department of education has notified the commonwealth s 132 school divisions that as many as 4 000 school buses may need retrofitting this summe. A bus door service brake interlock system having a warning system is provided. Bus door safety systems 1.

The purpose of this recommended practice is to provide a uniform method and criteria for testing and verification of transit bus brake system performance. Interlock and emergency brake systems are not covered in this document. A brake interlock system could easily allow a driver being held at gunpoint the means to prevent the bus from moving by purposely not following the required release steps and claiming mechanical problems to the assailant thus giving law enforcement more time to respond. A bus door service brake interlock system having a warning system is provided.

This specification sets the criteria for the design of a bus door safety system which is intended to prevent passengers from being trapped in the doors of a moving bus 1 2. A bus door service brake interlock system having a warning system is provided to inform a driver that the service brake pressure is insufficient or not being applied at all as well as indicating if a system malfunction occurs precluding a service brake application. Door interlock kit spring brake control valve to accessories ttypical school bus air system schematicypical school bus air system schematic wwith a bendixith a bendix ad isad is air dryerair dryer test 3 pressure modulator valve and traction control valve chuff full pressure engine stopped parking brakes released ok not ok. The system is based on a sequential operation of the driver activating the caution lights and opening the door.

The interlock system includes a foot valve assembly to effect a service brake application when warning lights are activated a vehicle door is open and minimum speed conditions are met. If air pressure fails in the piston chamber the power spring applies the brakes and unless pressure can be reestablished the service brakes must be released as follows in order to move the coach. A door brake interlock system or the bus stop brake to secure the bus. There are engineering systems in place which are designed to prevent incidents of runaway buses.

These are however not substitutes for drivers vigilance in ensuring that the park brake is always applied before leaving the drivers seat. The interlock system includes a foot valve assembly to effect a service brake application when warning lights are activated a vehicle door is open and minimum speed conditions are met.