Tilt-Head Stand Mixer Coupling Assembly to Minimize Yaw and Roll
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tilt-head stand mixers experience imprecise fits between the pin and hole features, leading to yaw, roll, and other unwanted movements of the mixing head due to manufacturing tolerances, affecting the desired pitch rotation.
Innovation Solution
A coupling assembly with a pin body and pivot frame that includes cylindrical segments and support receptacles, secured by screws, ensures precise alignment and rotation of the mixing head between lowered and raised positions, minimizing roll and yaw movements through a zero-tolerance fitting and over-molded plastic frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pin passes through holes in the base cheeks and mounting tongue, then the mixing head can be coupled to the base with pitch rotation capability, but manufacturing tolerances cause imprecise fits resulting in unwanted yaw and roll movements
Solution Approach 1:
A spherical bearing is introduced as an intermediary element between the pin and the mounting tongue. The spherical bearing receives the pin and provides a precise, zero-tolerance fit through its internal geometry, eliminating the unwanted yaw and roll movements while preserving the desired pitch rotation capability. The spherical bearing acts as a mediator that compensates for manufacturing tolerances in the pin and hole features.
Solution Approach 2:
The coupling mechanism transitions from a direct pin-through-hole connection to a pin-spherical bearing connection. This parameter change in the coupling geometry allows the spherical bearing to accommodate manufacturing tolerances while maintaining precise rotational movement. The spherical bearing's geometry transforms the tolerance-sensitive linear fit into a tolerance-resilient rotational joint.
2Manufacturing precision
If the pin fit is made tighter to eliminate yaw and roll, then manufacturing precision improves, but the complexity of manufacturing and assembly increases
Solution Approach 1:
The spherical bearing serves as an intermediary that simplifies the overall coupling assembly by consolidating multiple alignment functions into a single component. Rather than requiring precisely machined holes and tight pin fits, the spherical bearing provides the necessary precision through its internal geometry, reducing manufacturing complexity while maintaining high fit precision.
Solution Approach 2:
The coupling assembly combines different materials and geometries - the pin (metal), the spherical bearing (precision-engineered component with spherical geometry), and the mounting tongue - to achieve precise movement control. This composite approach allows each component to be optimized for its specific function, reducing overall assembly complexity while maintaining high precision.
3Device complexity
If traditional pin-and-hole coupling is used, then device complexity is low, but the mixing head exhibits unwanted yaw and roll movements affecting stability
Solution Approach 1:
The spherical bearing acts as a stabilizing intermediary between the pin and mounting tongue. It filters out unwanted yaw and roll movements while allowing the intended pitch rotation to occur freely. The spherical geometry provides inherent stability by constraining movement to the desired degree of freedom while accommodating manufacturing tolerances.
Solution Approach 2:
The coupling assembly transitions from a static rigid connection to a dynamic joint with controlled degrees of freedom. The spherical bearing enables the mixing head to rotate dynamically in the desired pitch direction while automatically constraining unwanted yaw and roll movements, providing stability through dynamic constraint rather than rigid fixation.
Data Source
AI summary
A stand mixer includes a base defining an interior with an opening to the interior and a mixing head being supported over an upper mounting area of the base and defining a mounting tongue extending through the opening to the interior of the base. The stand mixer further includes a coupling assembly including a pin body extending between opposite first and second ends and a pivot frame including first and second support receptacles respectively receiving the first and second ends of the pin body and a frame body connecting the first and second support receptacles. The frame body is secured to the base within the interior thereof, and the pin body is secured to the mounting tongue of the mixing head to pivotably couple the mixing head to the base with the mixing head being rotatable on the base between a lowered position and a raised position.