Four-Bar Linkage Assembly Preventing Implement Collision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Skid steer loaders lack a mechanism to prevent the implement from colliding with the operator cab when erroneously operated, as existing designs do not restrict the movement of the implement beyond a certain angle.
Innovation Solution
A four-bar linkage assembly is introduced, featuring an arm pivot pin that couples the front and rear arms, with a tilt cylinder and extension cylinder system, where the angle between the rear arm and bracket is between 0 and 90 degrees, preventing the work tool from swinging into the operator station.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the implement is allowed to rotate freely beyond a fixed angle, then the operational flexibility and range of motion are improved, but the risk of collision with the operator cab increases
Solution Approach 1:
The patent applies preliminary anti-action by designing the four-bar linkage geometry to preemptively prevent the implement from reaching positions that would cause collision. The specific angular relationship (0-90 degrees at the arm pivot pin) creates inherent geometric constraints that stop the implement before it can contact the operator cab, rather than relying on active sensors or brakes to react after a collision risk is detected.
Solution Approach 2:
The patent changes the geometric parameters of the linkage system, specifically setting the angle at the arm pivot pin between 0 and 90 degrees. This parameter change transforms the linkage into a four-bar assembly with constrained motion characteristics that inherently limit the implement's rotation range, converting an unbounded rotation problem into a bounded geometric solution.
2Reliability
If a mechanical constraint system is added to limit implement movement, then the safety is improved, but the device complexity increases
Solution Approach 1:
The four-bar linkage assembly serves multiple functions simultaneously: it provides the necessary motion control for implement operation, enforces safety constraints through geometric design, and eliminates the need for separate limiting mechanisms. By making the linkage itself multi-functional, the patent avoids adding complexity while achieving safety goals.
Solution Approach 2:
The linkage system is self-constraining through its geometric design. The four-bar configuration with the specified angular relationship automatically limits the implement's motion range without requiring external control systems, sensors, or additional actuating mechanisms. The structure serves itself to enforce safety constraints through pure geometry.
Data Source
AI summary
A four-bar assembly for a linkage assembly includes an arm pivot pin pivotally coupling a front arm with a rear arm of the linkage assembly. The arm pivot pin forms a first vertex of the four-bar assembly. A distal end of the front arm forms a second vertex of the four-bar assembly. The four-bar assembly includes a tilt cylinder having a first end and a second end. The first end of the tilt cylinder is pivotally coupled to a bracket angularly extending from the rear arm at a first end pin. The first end pin forms a third vertex of the four-bar assembly and the second end of the tilt cylinder forms a fourth vertex of the four-bar assembly respectively. An angle formed at the arm pivot pin and defined between the rear arm and the bracket lies between 0 and 90 degrees.