Hand-Held Tool Gear Clamping via Prestressed Connecting Elements
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Solution Overview
Problem
Hand-held power tools, such as drilling and percussion hammers, face challenges in securely fixing the gear device between external components while efficiently transmitting prestressing forces, which affects the tool's stability and ease of assembly/disassembly.
Innovation Solution
The use of multiple connecting elements, preferably four, to transmit prestressing forces between outer components, clamping the transmission device and providing a stable, secure, and space-efficient arrangement, with features like expanded shanks and detachable connections for easy maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If multiple connecting elements are used to transmit prestressing forces between outer components, then the clamping stability of the transmission device is improved, but the device complexity increases
Solution Approach 1:
The patent combines multiple connecting elements into a unified clamping system that works together to secure the transmission device. The connecting elements are integrated with the outer components to form a cohesive assembly, reducing the need for separate fastening mechanisms and thereby managing complexity while achieving stable clamping.
Solution Approach 2:
The connecting elements are designed to be pre-assembled or pre-positioned on the outer components before final assembly. This preliminary arrangement ensures that the prestressing forces are correctly applied and distributed, achieving stable clamping from the outset without requiring complex adjustment mechanisms during final assembly.
2Reliability
If connecting elements are made long to ensure effective prestressing forces, then the prestressing effectiveness is improved, but the space requirement increases
Solution Approach 1:
The connecting elements are designed to nest within or alongside other components of the hand-held power tool. This nesting arrangement allows the connecting elements to be sufficiently long to provide effective prestressing forces while occupying minimal additional space within the compact tool housing.
Solution Approach 2:
Instead of extending connecting elements in a straight line, the design utilizes three-dimensional routing where connecting elements may bend, angle, or follow complex paths around other components. This allows the connecting elements to achieve the necessary length for effective prestressing without increasing the overall external dimensions of the tool.
3Stability of the object's composition
If the gear device is tightly clamped between outer components, then the positional stability is improved, but the ease of disassembly deteriorates
Solution Approach 1:
The connecting elements incorporate dynamic features such as threaded adjustments or release mechanisms that allow the clamping force to be easily modified. During normal operation, the connecting elements maintain tight clamping for positional stability, but during maintenance, the dynamic features enable quick release to facilitate disassembly and reassembly.
4Strength
If multiple connecting elements are used to absorb tilting moments, then the structural stability is improved, but the manufacturing complexity increases
Solution Approach 1:
The connecting elements are designed as separate, modular components that can be manufactured independently using standard manufacturing processes. Each connecting element is a discrete piece that can be produced through common techniques such as machining or forming, avoiding the need for complex integrated structures and thereby reducing manufacturing complexity while maintaining structural stability.
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 solution ensures a stable clamping of the transmission device, effectively absorbs tilting moments, and allows for simple disassembly and maintenance, while maintaining a compact and secure connection between components, ensuring reliable operation and reduced component count.
Implementation Method 1
The preload forces are generated by tensile forces in the connecting elements
Implementation Method 2
The prestressing forces can be generated by a spring action of the connecting elements
Implementation Method 3
The transmission device clamped between the outer components exerts compressive forces that oppose the prestressing forces on the outer components
Implementation Method 4
The position of the transmission device can be fixed in directions transverse to the prestressing forces by a frictional connection, in particular by static friction
Data Source
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AI summary
The invention relates to a hand-held machine tool, in particular a hammer drill or a percussion hammer, having at least one gear device (12a; 12b) and having at least two outer components (14a; 14b; 16a; 16b), between which the gear device (12a; 12b) is arranged. According to the invention, at least three connection elements (18a, 18b; 20a; 20b; 22a; 20b; 24a; 24b) are provided to transmit prestress forces (26a; 26b) between the outer components (14a; 14b; 16a; 16b), which forces clamp the gear device (12a; 12b) between the outer components (14a; 14b; 16a; 16b).