Patent Application
20200116223
The present invention relates to embodiments of an apparatus to mount an actuator assembly to an air disc brake caliper for an air brake equipped vehicle.
Air disc brakes convert air pressure into braking force. When the driver applies the vehicle brake pedal, air enters the service brake chamber of an actuator assembly through a supply port. The pressure expands a diaphragm, moving a pressure plate and a pushrod of the actuator assembly forward. When the actuator assembly is mounted to an air disc brake assembly, the pushrod acts against an internal lever of the air disc brake, resulting in movement of the inner brake pad toward the rotor. Further movement of the bridge inside the air disc brake forces the caliper away from the rotor, pulling the outer brake pad into the rotor. Proper alignment of the actuator assembly with respect to the caliper body of the air disc brake is necessary to ensure that the push rod correctly acts on the lever. A very precise angle may need to be maintained between the axis of the caliper and the axis of the actuator when mounting.
Some actuator assemblies have at least one fixed bolt for attachment to the caliper. A special tool is used to affix a nut to the bolt when the actuator is set flush with a face of the caliper. In some configurations, the tool is unable to surround the nut for proper installation due to the angle of insertion of the bolt into the caliper and interference with the body of the caliper. If the actuator is not flush with the caliper, there may be reduced function or loss of function of the air disc brake assembly. Therefore, there is a need for an improved method and apparatus for mounting an actuator assembly to a caliper in a braking assembly.
Various embodiments of an actuator assembly comprise an actuator housing having a service portion and at least one mounting stud attached to the service portion. The at least one mounting stud is pivotable with respect to the actuator housing.
In accordance with another aspect, various braking assemblies for an air disc brake comprise an actuator assembly having a service portion; at least one mounting stud attached to the service portion, and an air disc brake caliper having a bore for receiving the at least one mounting stud. The mounting stud is pivotable with respect to the service portion for installation on the air disc brake caliper.
In the accompanying drawings which are incorporated in and constitute a part of the specification, embodiments of the invention are illustrated, which, together with a general description of the invention given above, and the detailed description given below, serve to exemplify the embodiments of this invention.
An angle, theta, is established so that the push rod (not shown) of the actuator assembly 12 acts upon a lever 15 inside the air disc brake caliper 16. A face 13 of the caliper 16 is generally at the angle theta with respect to the axis of the brake assembly 10 to accept the actuator assembly 12. The angle theta is typically between zero degrees and twelve degrees to provide clearance for other wheel end components. The fastener 14 of the actuator assembly 12 is positioned through a bore 17 that exits at the face 13 of the caliper 16. The bore 17 is drilled into the caliper 16 at the angle required for the proper mounting of the actuator assembly 12 and normal to the face 13 of the caliper 16. A nut 18 is required to be threaded onto the fastener 14 to hold the actuator assembly 12 in place on the caliper 16. In general, a tool 19 is used to fasten the nut 18 to the fastener 14. The tool 19 may not fit properly over the fastener 14 and interfere with the caliper 16 due to the angle of the bore 17.
Therefore, an actuator assembly comprises an actuator housing having a service portion and at least one mounting stud attached to the service portion. The at least one mounting stud is pivotable with respect to the actuator housing.
The receiving portion 24 includes a socket 34. The socket 34 may also have flat portion 35 to mate with the flats 32 of the threaded portion 26. In this manner, the threaded portion 26 will not rotate but rather be able to pivot in a single plane once installed. The angle of the pivot is controlled by the geometry of the mounting stud with respect to the features of the actuator assembly.
Alternatively, a pin can be placed axially through a hole in the threaded portion and the receiving portion to hold threaded portion in the receiving portion while allowing the threaded portion to pivot.
The materials of the receiving portion 24 and threaded portion 26 are metallic, such as stainless steel. The materials can be the same in order to facilitate movement between the receiving portion 24 and threaded portion 26.
The actuator assembly 21 includes mounting stud 22a. The threaded portion 26 of mounting stud 22a is positioned through a bore 28 in the caliper 27. The angle at which the bore 28 is drilled is no longer required to be normal to the angled mounting face of the caliper 27. The bore 28 is drilled parallel to the axis of the caliper 27. The tool 19 fits over the threaded portion 26 without interfering with the caliper 27 in order to fasten the nut 18 onto the threaded portion 26. As the nut 18 is threaded, the actuator assembly 21 is pulled flush to the face of the caliper 27 at the required angle theta.
With the actuator assembly 21 having the pivotable mounting studs 22a, 22b, nearly any angle theta between 0 degrees and 45 degrees can be contemplated. One application may include angles between 0 and 20 degrees. The restrictions are based on the angled mounting face of the caliper 27 and the envelope in which the entire brake assembly 20 must fit in on a vehicle.
Therefore, various braking assemblies for an air disc brake comprise an actuator assembly having a service portion; at least one mounting stud attached to the service portion, and an air disc brake caliper having a bore for receiving the at least one mounting stud. The mounting stud is pivotable with respect to the service portion for installation on the air disc brake caliper.
A brake assembly having the features of the present invention is easier to assembly since there is more space to maneuver the tool to attach the nut. Additional envelope space is provided in the caliper for inner mechanisms since the bore hole can be parallel to the caliper axis. Another advantage is that actuators with traditional non-pivoting fasteners would not fit on the calipers with the different mounting bore angle.
While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept.
