Keyless Chuck Locking Mechanism for Inadvertent Opening
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Solution Overview
Problem
Existing chucks for power drivers lack a secure mechanism to prevent inadvertent opening, especially when subjected to torque variations during tool usage, which can lead to loose grip on tool shanks.
Innovation Solution
A keyless chuck design featuring a rotatable sleeve, a nut with locking teeth, and a lock ring with projections that engage and disengage with locking teeth to resist rotation in the opening direction, ensuring the chuck remains closed under operational torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a keyless chuck is rotated by hand for tightening or loosening, then ease of operation is improved, but reliability deteriorates due to lack of secure locking mechanism against torque variations
Solution Approach 1:
The locking teeth and projections are pre-configured on the body and lock ring respectively, creating a automatic locking mechanism that engages when the chuck is tightened. This preliminary arrangement of locking elements ensures that once the chuck is manually tightened, the locking mechanism automatically prevents inadvertent opening without requiring additional manual intervention.
Solution Approach 2:
The lock ring acts as an intermediary element between the rotating sleeve and the stationary body. It transfers the rotational motion from the sleeve to the nut while the locking teeth and projections prevent reverse rotation. This intermediary mechanism allows easy manual operation while simultaneously providing reliable protection against inadvertent opening.
2Reliability
If a locking mechanism with projections and locking teeth is added to prevent inadvertent opening, then reliability is improved, but device complexity increases
Solution Approach 1:
The locking mechanism is merged into the existing chuck structure by integrating the locking teeth directly onto the body and the projections onto the lock ring. These elements are combined with the nut and sleeve assembly rather than being separate additional components. This merging approach provides reliable locking while minimizing the increase in overall device complexity.
Solution Approach 2:
The locking mechanism is designed to be self-actuating through the normal tightening operation. As the sleeve is rotated to tighten the chuck, the lock ring rotates with it, and the projections automatically engage with the locking teeth on the body. The mechanism serves itself by using the tightening motion to activate the locking function without requiring separate locking actions or complex control systems.
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 design provides a secure grip on tool shanks and prevents inadvertent opening, ensuring consistent tool engagement and reducing the risk of accidental loosening during use.
Implementation Method 1
The chuck includes a nut that rotates about the chuck center and that engages threads on the jaws so that rotation of the nut moves the jaws in either direction within the passageways
Implementation Method 2
A lock ring includes an annular portion and at least three projections extending from the annular portion toward the nose section of the body and the locking teeth, the lock ring being non-rotatable with respect to the nut and axially movable with respect to the body, the projections and the locking teeth being configured so that when the projections engage the locking teeth, the projections and the locking teeth resist rotation of the lock ring in the opening direction with respect to the body
Implementation Method 3
A generally cylindrical sleeve is rotatably mounted about the body, the sleeve being in operative communication with the nut so that the sleeve rotationally drives the nut
Data Source
AI summary
A chuck including a body having a nose section, a tail section and a center axis, the nose section defining an axial bore and a plurality of passageways. A plurality of jaws is disposed in the passageways, a nut is rotatably mounted about the body so that rotation of the nut either moves the jaws toward or away from the center axis, and a sleeve that is rotatably mounted about the body, the sleeve being rotatable with respect to the nut between a first rotational position and a second rotational position. An annular array of locking teeth is non-rotatable with respect to one of the body and the nut. A lock ring includes at least three projections and is axially movable so that, when engaged, the projections and the locking teeth resist the lock ring from rotating in the opening direction with respect to the body.