BRAKE ACTUATOR WITH CENTERING DOME IN SERVICE CHAMBER

摘要

An improved spring brake actuator includes a dome (42) extending into the service chamber (36) from the center housing (32). The spring chamber push rod (22) is formed with a plate (40) having a cross section corresponding to the dome (42). The service chamber diaphragm (38) as well as the service chamber piston (46) are also formed with surfaces that correspond to the shape of the dome (42). The surfaces "stack up" to ensure alignment between the spring chamber push rod (22) and the service chamber push rod (49). The use of the dome (42) also provides additional stroke to the spring chamber push rod (49) without requiring additional axial length for the overall brake actuator.