Spring brake actuator with mid-located spring

A spring brake actuator mechanism, comprising:

• a brake actuator spring;
• a parking brake release actuator;
• a spring retainer;
• and
• a connecting shaft,
• wherein the parking brake release actuator, spring retaining and connecting shaft are configured to permit the parking brake release actuator to be coupled to the spring retainer by the connecting shaft extending therebetween, with the connecting shaft passing axially through the brake actuator spring.

A vehicle brake assembly, comprising:

• a brake, wherein the brake includes one of a disc brake caliper and a drum brake;
• and
• a spring brake actuator coupled to the brake to apply a brake actuation force, the spring brake actuator having a housing containing
• a brake actuator spring,
• a service brake actuator
• a parking brake release actuator;
• a brake actuator rod disposed at a brake end of the housing;
• a spring retainer;
• and
• a connecting shaft,
• wherein
• the brake actuator spring is disposed between the service brake actuator and the parking brake release actuator,
• the parking brake release actuator is coupled to the spring retainer by the connecting shaft and the brake actuator spring is disposed between the parking brake release actuator and the spring retainer,
• the spring retainer bears against the service brake actuator in a non-coupled manner when the parking brake release actuator is in an un-actuated state, and
• the service brake actuator is coupled to the actuator rod such that when the service brake actuator is actuated, the actuator rod is displaced axially from the housing in a brake actuation direction,

A vehicle axle assembly, comprising:

• a vehicle axle;
• a brake coupled to the vehicle axle, wherein the brake includes one of a disc brake caliper and a drum brake;
• and
• a spring brake actuator coupled to the brake to apply a brake actuation force, the spring brake actuator having a housing containing
• a brake actuator spring,
• a service brake actuator
• a parking brake release actuator;
• a brake actuator rod disposed at a brake end of the housing;
• a spring retainer;
• and
• a connecting shaft,
• wherein
• the brake actuator spring is disposed between the service brake actuator and the parking brake release actuator,
• the parking brake release actuator is coupled to the spring retainer by the connecting shaft and the brake actuator spring is disposed between the parking brake release actuator and the spring retainer,
• the spring retainer bears against the service brake actuator in a non-coupled manner when the parking brake release actuator is in an un-actuated state, and
• the service brake actuator is coupled to the actuator rod such that when the service brake actuator is actuated, the actuator rod is displaced axially from the housing in a brake actuation direction,

A vehicle, the vehicle being self-propelled vehicle or a non-self-propelled trailer, comprising:

• a vehicle body;
• a vehicle axle coupled to the vehicle body;
• a brake coupled to the vehicle axle, wherein the brake includes one of a disc brake caliper and a drum brake;
• and
• a spring brake actuator coupled to the brake to apply a brake actuation force, the spring brake actuator having a housing containing
• a brake actuator spring,
• a service brake actuator
• a parking brake release actuator;
• a brake actuator rod disposed at a brake end of the housing;
• a spring retainer;
• and
• a connecting shaft,
• wherein
• the brake actuator spring is disposed between the service brake actuator and the parking brake release actuator,
• the parking brake release actuator is coupled to the spring retainer by the connecting shaft and the brake actuator spring is disposed between the parking brake release actuator and the spring retainer,
• the spring retainer bears against the service brake actuator in a non-coupled manner when the parking brake release actuator is in an un-actuated state, and
• the service brake actuator is coupled to the actuator rod such that when the service brake actuator is actuated, the actuator rod is displaced axially from the housing in a brake actuation direction,

A method of operating a spring brake actuator, the spring brake actuator having a housing containing

• a brake actuator spring,
• a service brake actuator
• a parking brake release actuator;
• a brake actuator rod disposed at a brake end of the housing;
• a spring retainer;
• and
• a connecting shaft, wherein
• the brake actuator spring is disposed between the service brake actuator and the parking brake release actuator,
• the parking brake release actuator is coupled to the spring retainer by the connecting shaft and the brake actuator spring is disposed between the parking brake release actuator and the spring retainer,
• the spring retainer bears against the service brake actuator in a non-coupled manner when the parking brake release actuator is in an un-actuated state, and
• the service brake actuator is coupled to the actuator rod such that when the service brake actuator is actuated, the actuator rod is displaced axially from the housing in a brake actuation direction,
• the method comprising the acts of:
• applying pneumatic or hydraulic pressure to a parking brake release chamber formed by a rear portion of the housing and the parking brake release actuator such that the spring retainer biases the brake actuator spring away from the service brake actuator;
• and
• applying pneumatic or hydraulic pressure to a service brake chamber formed by a front portion of the housing and the service brake actuator such that the actuator rod is displaced axially from the housing in a brake actuation direction.

A method of assembling a spring brake actuator, comprising the acts of:

• locating a brake actuator spring between front side of an actuator housing flange and a rear side of a spring retainer;
• coupling the spring retainer to a parking brake release actuator disposed on a rear side of the actuator housing flange;
• applying a pre-load force to the brake actuator spring;
• and
• disposing a front side of the spring retainer adjacent to a rear side of a service brake actuator located in a portion of the spring brake actuator in front of the actuator housing flange.

A spring brake actuator, wherein

• application of pneumatic or hydraulic pressure to a parking brake release pressure chamber biases a brake actuator spring in a brake release direction;
• application of pneumatic or hydraulic pressure to a service brake pressure chamber displaces a brake actuator rod in a brake application direction;
• removal of said pneumatic or hydraulic pressure in the parking brake release pressure chamber permits a spring force generated by the brake actuation spring to bias the service brake actuator in the brake application direction;
• and
• the brake actuator spring is disposed between the service brake actuator and the parking brake release actuator.

A spring brake actuator, comprising:

• a brake actuator energy storage and return means;
• a parking brake release actuator means;
• and
• a service brake actuator means,
• wherein the brake actuator energy storage and return means is disposed between the service brake actuator means and the parking brake release actuator means.