Portable Power Tool Gear Switching Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Handheld power tools with existing gear units lack efficient mechanisms for seamlessly switching between multiple operating modes, such as drilling, percussion drilling, and chiseling, often resulting in complex designs, high component count, and increased costs.
Innovation Solution
A hand-held power tool with a rotatably mounted lever switching means on an intermediate flange, featuring at least two shift sleeves on a shaft, allows for simple switching between gear stages by engaging the switching means in a space between the sleeves, utilizing a spring unit to store and apply shifting forces, enabling low-wear and cost-effective operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple separate switching mechanisms are used to control different gear stages, then each gear stage can be switched independently, but the device complexity and component count increase significantly
Solution Approach 1:
The patent combines multiple switching functions into a single integrated switching means (lever 16) that can control at least three different gear stages. This single lever replaces what would traditionally require multiple separate switching mechanisms, thereby reducing device complexity while maintaining full gear stage switching capability.
Solution Approach 2:
The switching means is designed as a multi-functional component that can operate multiple gear stages through a single mechanism. The lever 16 can engage with different shift sleeves (18, 20) to control drilling mode, percussion drilling mode, and chiseling mode, making one component perform the work of multiple separate switches.
2Adaptability or versatility
If more shift sleeves are added to control additional gear stages, then more operating modes can be achieved, but the device complexity increases
Solution Approach 1:
Multiple shift sleeves (18, 20) that control different operating modes are mounted together on a single common shaft (22). This merging of multiple shifting components onto one shaft reduces the overall structural complexity compared to having separate shafts or mounting arrangements for each shift sleeve, while still enabling multiple operating modes.
Solution Approach 2:
The common shaft serves as a universal mounting structure for multiple shift sleeves, each responsible for different gear stages. This universal shaft design allows the transmission unit to achieve multiple operating modes (drilling, percussion drilling, chiseling) without proportionally increasing structural complexity.
3Ease of manufacture
If the switching means is mounted away from the gear unit, then the housing can be simplified, but the switching path becomes longer and operation less efficient
Solution Approach 1:
The intermediate flange (12) serves as an intermediary mounting surface that bridges the housing structure and the gear unit. By mounting the switching means on the intermediate flange rather than directly on the housing, the design achieves both structural simplicity and operational efficiency, as the intermediate flange is already positioned close to the gear unit components.
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
This configuration enables user-friendly, compact, and cost-effective operation by allowing seamless switching between modes with reduced wear and force-free intervention in gear stages, enhancing the tool's usability and durability.
Implementation Method 1
a spring unit (34) which is provided for applying a spring force to a switching sleeve (18, 20) at least in one operating mode
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a portable power tool, in particular a boring and/or chisel hammer, with an intermediate flange (12) and a gear unit (14) which has switch means (16) mounted on the intermediate flange (12). It is proposed that the switch means (16) be provided to switch at least three gear stages of the gear unit (14).