Keyless Chuck Assembly with Freewheel Brake for Medical Drill
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Solution Overview
Problem
Keyless chuck assemblies for medical hand drills/mills are cumbersome to operate, especially when changing tools, as they require two-handed operation and are not suitable for bidirectional rotation, leading to potential tool sticking and increased surgical risk.
Innovation Solution
A keyless chuck arrangement with a freewheel brake and a step-up/step-down gear with integrated shaft lock, allowing for one-handed operation and secure tool clamping in both directions by preventing unintentional opening during counter-rotation, and eliminating the need for a retaining ring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a keyless chuck assembly with two sleeves (housing and grip ring) is used, then tool clamping is achieved without a wrench, but operation becomes cumbersome requiring two hands
Solution Approach 1:
The patent removes the grip ring from the chuck assembly, extracting the problematic two-sleeve structure. The housing alone performs both clamping and opening functions through its interaction with the pressure spindle, eliminating the need for a separate grip ring and reducing structural complexity while maintaining ease of operation.
Solution Approach 2:
The housing is designed to perform multiple functions: it serves as both the clamping structure and the operating element. By integrating the functions of the housing and grip ring into a single housing structure with appropriate threading and engagement features, the assembly achieves multi-functionality without requiring separate components.
2Adaptability or versatility
If a keyless chuck assembly with pressure spindle is used, then wrench-free operation is achieved, but the assembly becomes unsuitable for bidirectional rotation
Solution Approach 1:
The patent employs a dynamic threading system where the housing and pressure spindle have reverse threads. During clockwise rotation, the pressure spindle engages to clamp the tool; during counterclockwise rotation, the reverse threading allows the pressure spindle to disengage and re-engage appropriately, enabling bidirectional rotation while maintaining clamping security through dynamic adaptation to rotation direction.
Solution Approach 2:
The patent uses reverse threading on the pressure spindle compared to conventional designs. Instead of a standard right-hand thread, the pressure spindle employs a left-hand thread configuration that allows it to engage and disengage based on rotation direction, enabling the chuck to function securely in both clockwise and counterclockwise rotations by inverting the traditional threading approach.
3Reliability
If a retaining ring is added to prevent unintentional opening, then tool clamping security is improved, but device complexity increases
Solution Approach 1:
The patent eliminates the retaining ring by redesigning the pressure spindle engagement mechanism. The pressure spindle is designed with features that prevent unintentional opening through its interaction with the housing threading and clamping jaw geometry, removing the need for a separate retaining ring component while maintaining tool clamping security.
Solution Approach 2:
The housing and pressure spindle are designed to perform the security function previously required by a separate retaining ring. The threading configuration and engagement features of the housing-pressure spindle system provide inherent protection against unintentional opening, integrating the security function into the existing structural components rather than requiring an additional element.
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
Enables easy and secure tool changes with one person, reduces the risk of tool sticking, and allows for safe operation in both clockwise and counterclockwise directions, enhancing ergonomic handling and reducing surgical risks.
Implementation Method 1
a freewheel that can be activated and/or deactivated is provided between the drive shaft and the chuck housing
Implementation Method 2
a pressure spindle which is in threaded engagement with a drive shaft
Data Source
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AI summary
The keyless chuck assembly has a manually or automatically activated and deactivated free-wheel that is arranged between a drive shaft (1) and a chuck housing. The clamping jaws (6), particularly three clamping jaws, are provided in the chuck housing, where the jaws are axially displaced by a pressure spindle (4). The free-wheel is rotated by the drive shaft in the activated state relative to the chuck housing. A manually or automatically operated clutch is arranged between the free-wheel and the chuck housing or between the free-wheel and the drive shaft.