Offset Drum Brake Lever Structure for Lateral Load Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High offset angles in brake levers for drum brakes in heavy-duty vehicles induce significant lateral loads on the brake shaft and slack adjuster, leading to premature wear and damage.
Innovation Solution
Incorporation of a stiffening member within the brake lever design that absorbs lateral efforts, acting as a support leg to reduce stress on the brake shaft and slack adjuster, while maintaining the necessary offset for packaging constraints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the brake lever includes angled parts with high offset to overcome packaging constraints, then the packaging constraints are satisfied, but significant lateral loads are induced on the brake shaft causing wear and tear
Solution Approach 1:
The brake lever is segmented into multiple portions (first portion, second portion, third portion) connected by pivot points, allowing the lever to achieve the necessary offset angle while distributing lateral loads across multiple connection points rather than concentrating them on the brake shaft
Solution Approach 2:
Different portions of the brake lever have different structural characteristics optimized for their specific functions - the first portion connects to the brake shaft with specific geometric features, the second portion contains the slack adjuster mechanism, and the third portion connects to the push rod, allowing each section to handle local stress conditions appropriately
2Volume of moving object
If the offset between brake lever connection points is increased to satisfy packaging constraints, then packaging is improved, but lateral loads on the slack adjuster increase causing accelerated damage
Solution Approach 1:
The brake lever is divided into distinct portions with the slack adjuster mechanism housed in the second portion, separating the slack adjustment function from the primary braking force transmission path, thereby protecting the slack adjuster from excessive lateral loads while maintaining the required offset angle
Solution Approach 2:
The pivot connections between lever portions act as intermediaries that redirect and distribute lateral loads away from the slack adjuster mechanism, allowing the lever to maintain the necessary offset angle without subjecting the slack adjuster to damaging lateral forces
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The stiffening member effectively reduces wear and tear on the brake shaft splines and slack adjuster, enhancing the brake lever's ability to withstand lateral stress and extending its operational lifespan.
Implementation Method 1
the stiffening member absorbs at least a part of the lateral efforts to which the brake shaft is exposed in the connection area with the brake shaft
Implementation Method 2
brake lever being designed for transmitting the movement of a cylinder rod to a brake shaft
Implementation Method 3
A cam, e.g. a S-shaped cam, is arranged at the end of the brake shaft. As the cam rotates, it forces two symmetrical brake pads against the brake drum
Implementation Method 4
The friction between lining and drum provides the braking effort. Energy is dissipated as heat
Data Source
AI summary
The invention relates to a brake lever (20) for a drum brake arrangement (12), said brake lever being designed for transmitting the movement of a cylinder rod (14) to a brake shaft (22), wherein the brake lever (20) comprises a first portion (20a) delimiting a hole (24) for fitting the brake shaft (22) and a second portion (20b), which is configured to be pivotally connected to the cylinder rod (14) and wherein the first portion and the second portion are offset from each other with respect to a central axis (X24) of the hole (24). The brake lever further includes a stiffening member (28) that extends along a direction (L1) contained inside a plane (P1) perpendicular to the central axis (X24) of the hole and that includes an orifice (32) for fitting the brake shaft (22).