RELEASE BOLT INDICATOR FOR SPRING BRAKE ACTUATORS

BACKROUND OF THE INVENTION

The present invention is for spring brake actuators with fixed release bolt and relates to the system alerting the operator that the actuator is released manually by release bolt.

PRIOR ART ABOUT THE INVENTION

A spring brake actuator consists of service brake chamber operating under normal driving conditions and park chamber steps in if there is air leakage or in case the air is exhausted intentionally. Normally emergency spring in the park chamber is compressed with compressed air. As the power springs is released when the compressed air is exhausted by leakage or the air is exhausted intentionally, the energy stored in the emergency spring is converted into braking force and provides braking.

In order to move the stopped vehicle under conditions other than aforementioned normal driving conditions, the vehicle shall not be in braking position. Therefore the power spring expanded in park chamber must be caged manually. In order to maintain this procedure, a threaded steel shaft -called Release bolt- integrated to actuators are used. As the release bolt is turned, the piston holding the emergency spring compresses the emergency spring. Since the caged spring does not output a force, braking does not occur and the vehicle can be moved.

The concept of "released actuator" means that the emergency spring in the actuator is manually caged. And the system providing to cage this spring manually -which is normally compressed by compressed air- is the releasing system.

There are two types of mechanical release system used in the spring brake actuators at the present: Concerning the first type of mechanical release system; while the spring inside is compressed by turning the release bolt, the release bolt comes out of the canister (Figure 1). As a result of increase in the number of parts and improvement of the constructions especially for the new vehicles, the volume allocated to each part also decreases. Since the part of bolt coming out is long, in some cases it may hit to the other parts on the vehicle, and in some cases the operator can not reach to this part and turn the bolt easily due to the limited -narrow-space.

Concerning the second type of mechanical release system (Figure 2); the release bolt does not come out of the canister. The release bolt only turns within a simple bearing located on the canister and thus does not move along. A nut moving as the bolt is turned, actuates the piston and as a result the spring is compressed. Since the release bolt does not comes out, this system is of advantageous than the first type of release bolt system.

However this system has a disadvantage because; since the release bolt does not come out, the operator can not decide if the spring brake actuator is released or not by visual check.

AIMS FOR DEVELOPMENT OF THE INVENTION With the improvement of this invention relating to the spring brake actuators with fixed release bolt, it is proposed to improve a system alerting the operator that the actuator is released by means of an indicator. In this way;

• the release bolt sticks out a less amount than the existing designs,

• assembling to narrower spaces in the vehicle is possible, • operator can easily reach to this section when necessary,

• operator can decide if the spring brake actuator is released or not from a distance by looking to the moving end of release bolt.

DESCRIPTION OF THE FIGURES The description of the figures prepared for a better explanation of the indicator alerting the operator that the actuator is released position at spring brake actuator with fixed release bolt improved with this invention are specified below.

Figure 1- Spring brake actuator with coming out type of release bolt Figure 2- Spring brake actuator with fixed type of release bolt Figure 3- Spring brake actuator with release bolt indicator (the actuator is not released) Figure 4- Spring brake actuator with release bolt indicator (the actuator is released) Figure 5- Exploded view of release bolt with indicator set.

DEFINITION OF THE COMPONENTS (PARTS-FEATURES) ON THE FIGURES

The components-parts-features shown in the figures prepared for a better explanation of the indicator alerting the operator that the actuator is released position at spring brake actuator with fixed release bolt improved with this invention are numbered separately and explanation of each number is given below.

1- Aluminum pipe

2- Square Nut

3- Release bolt

4- Emergency Spring 5- Canister

6- Lock Nut

7- Adapter Plate

8- Piston

9- Ring 10- Spring

11- Ring 12- Pin

13- Indicator shaft 14- Return Spring 15- Bearing 16- 0 - Ring

SHORT DESCRIPTION OF THE INVENTION

When the actuator is manually released by turning the release bolt, a small part preferably red in color located inside of the release bolt in this invention comes out a less amount than the existing designs. In this way assembling to narrower spaces in the vehicle is possible and also operator can easily reach to this section when necessary.

A second benefit of the invention is that the the part which comes out when the actuator is in released position, can be seen easily by visual checking. Therefore this part works like an indicator, which is indicating wheather the actuator is released or not.

DESCRIPTION OF THE INVENTION IN DETAIL

The main parts of the indicator alerting the operator that the actuator is in released position with fixed release bolt improved with this invention are; Square Nut (2), Release bolt (3), Ring (9), spring (10), Ring (11), Pin (12), Indicator shaft (13), Return Spring (14), bearing (15) and O- Ring (16). Square Nut (2) takes place in the square bearing within the aluminum pipe (1). Instead of the Square Nut (2) its possible to use triangular or polygonal nut. In this case there will be triangular or polygonal sectioned groove instead of the square groove inside the Aluminum pipe (1).

On the one end of the Release bolt (3) between the two rings (9 and 11) there is spring (10) and on the end of Ring (9) there is Square Nut (2). On the other end of the Release bolt (3) there is Indicator shaft (13) accommodating a Pin (12) on one side, Return Spring (14), bearing (15) and O- Ring (16).

Except under normal driving conditions, when the vehicle is parking or in emergencies when there is air leakage, the brake force necessary to actuate the brakes is obtained through released emergency spring (4). This spring can provide a huge amount of force and it normally stays compressed between the Piston (8) and Canister (5) as the compressed air in the park chamber (A) pushes the Piston (8) during the vehicle is moving. (Figure 2)

In case there is no air in the park chamber (A), emergency spring (4) expands and pushes the Piston (8) and aluminum pipe (1) connected to the Piston (8); thus emergency spring (4) provides the necessary braking force to the braking system.

In case of a malfunction within the brake system where there is no compressed air, it shall be possible to compress the emergency spring (4) manually so as to compress the expanded emergency spring (4) and consequently release the vehicle from parking. At this stage, being turned by an appropriate wrench the Release bolt (3) enables the piston (8) to move towards (a) and compresses the emergency Spring (4) and the emergency spring (4) no longer produces force. Square Nut (2) attached on the Release bolt (3) can move along towards (a) and (b) directions inside the square bearing within the Aluminum pipe (1). As

the release bolt (3) is turned in clockwise the Square Nut (2) starts moving towards (a) direction inside the square groove within the Aluminum pipe (1). After several turns, Square Nut (2) seats at the stage formed at the interface part of Aluminum pipe (1) and piston (8). And henceforth moves together with the piston (8) and aluminum pipe (1) that the piston moves towards (a) direction and compresses the emergency spring (4). As releasing process continues, the movement of the square Nut (2) is transmitted to the ring (11) by means of a spring (10) enclosed on the Release bolt (3). The ends of aforementioned spring (10) are enclosed around the Rings (11) and (9). One of these rings (9) sticks to the square nut (2), and other sticks to a pin (12) placed on the Indicator shaft (13). This Pin (12) moves inside a cavity slotted on the Release bolt (3). Square Nut (2) also moves the ring (9) on which it is sticked during the release process and being squashed into the narrowed distance as the nut (2) goes forward, the spring (10) which is connected to the ring (9) pushes the other ring (11) and therefore the pin (12) which is in connection with the ring (11). As a result of the action, sticking out from the bearing (15), the Indicator shaft (13) alerts that the emergency spring (4) is caged, in other words the actuator is released.

As the Release bolt (3) is turned counter clockwise; the Square Nut (2) starts moving towards direction (b). Spring (10) is uncoiled as the Release bolt (3) is turned and the pressure effect gradually decreases and as a result; pushing the indicator shaft (13) Return Spring (14) provides the indicator shaft (13) totally move into the bearing (15) and return to the initial position. At this stage, the operator who is not able to see the tip of the indicator shaft (13) figures out that the emergency spring (4) is not caged and therefore the actuator is not released.