Hand Mixer Switch Mechanism for Tool-Dependent Operation Mode Control
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Solution Overview
Problem
Existing hand-held electric food processing devices are complex and prone to unintentional operation during continuous use due to lack of detents or spring preload, leading to potential injuries from sharp-edged tools and contamination from open housing openings.
Innovation Solution
A hand mixer with a locking mechanism that engages or disengages based on the type of tool coupled, allowing for automatic switching to short-term or continuous operation, and adjustable slide parts to secure housing openings, ensuring safe and efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spiral spring is mounted concentrically to the axis of rotation of the operating lever to automatically transfer the lever to the off position, then safety during improper handling is improved, but the device complexity increases
Solution Approach 1:
The housing opening is segmented into multiple states: open state for tool coupling, closed state for safety, and the operating lever is segmented into distinct positions (off, on, continuous operation) with detents providing stable stopping points. This segmentation allows the spring mechanism to effectively control the lever movement between discrete positions rather than requiring continuous control.
Solution Approach 2:
The spiral spring is pre-loaded to automatically return the operating lever to the off position when released. This preliminary action ensures that if the user accidentally releases the lever during continuous operation, it will automatically return to the safe off position, preventing unintended operation during improper handling.
2Reliability
If detents or spring preload are added to prevent unintentional operation during continuous use, then reliability is improved, but device complexity increases
Solution Approach 1:
Instead of requiring the user to actively maintain the switch in the on position, the system is designed so that the spring automatically returns the lever to the off position. The continuous operation mode is achieved by overcoming this spring force and engaging a detent, inverting the usual approach where the default state is on and requires active switching off.
Solution Approach 2:
The operating lever incorporates periodic detents at specific positions (off, on, continuous operation) that provide stable stopping points. These detents create a periodic structure in the lever's movement path, ensuring the lever settles into defined positions rather than remaining in intermediate states, thus preventing unintentional operation.
3Ease of operation
If housing openings remain open for tool coupling, then ease of operation is improved, but contamination risk increases
Solution Approach 1:
The housing opening is designed to be dynamic rather than static - it transitions between open and closed states based on operational needs. The opening can be opened for tool coupling and automatically closed during operation, providing both accessibility when needed and protection when not needed.
Solution Approach 2:
The housing opening is equipped with a spring-actuated mechanism that automatically closes the opening after tool insertion. This self-service feature eliminates the need for the user to manually close the opening, ensuring contamination protection is automatically activated while maintaining ease of operation.
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 device ensures safe operation by automatically switching off during improper handling and preventing contamination by securely closing unused tool openings, enhancing user safety and device reliability.
Implementation Method 1
a spiral spring is mounted concentrically to the axis of rotation of the operating lever and has a so-called fixed end connected to the operating lever and a so-called free end. Depending on which of the tools is coupled to the device and is to be driven by it, the tension of the spiral spring acts on the operating lever or not.
Implementation Method 2
The switch means have a detent which engages in a detent recess of the operating lever in the switching on position and in a further detent recess in the switching off position.
Data Source
Figure 1~2
Figure 4
Figure 5a~6c
AI summary
A hand-held electric stirring or mixing device, for example a hand mixer (1), is described, with an electric motor housed in a casing (2) for selectively driving different working tools, such as stirring or dough hooks (10) orblending wand (11), and with an actuating element (6) for opening or closing a switch (12) for switching the electric motor (7) on/off, wherein the switch (12) can be operated in short-term or continuous operation, wherein the different working tools (10, 11) can be inserted into different openings (26, 27; 28) of the housing (2) and driven by the electric motor (7), wherein the several openings (26, 27; 28) in the housing (2) for coupling different working tools (10, 11) can be selectively closed by means of a sliding plate (32) and wherein the sliding plate (32) is adjustable between a first and second end position (33, 34) in which either one or more openings (26, 27) for one tool (10) or the other opening (28) for the other tool (11) are closed.