Expandable Torque Tool Cam Jaw Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tools often fail to effectively engage and rotate stuck fasteners due to rust or other conditions, leading to slippage and the need for drilling a hole to remove them, as the drive flanks may not securely grip the fastener.
Innovation Solution
A torque tool with a body and jaws that expand within a socket or hole, featuring partly cylindrical receptacles and cam portions with flat flanks that move from a contracted to an expanded position, allowing secure engagement and torque transfer to the fastener.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a simple L-shaped rod with hexagonal exterior is used as a tool, then the device complexity is low, but the tool slips on the drive flats when the fastener is stuck due to rust or other conditions
Solution Approach 1:
The patent applies the dynamics principle by making the jaw expandable through a cam mechanism. The jaw transitions from a contracted state (for insertion) to an expanded state (for gripping), allowing the tool to adapt its dimensions dynamically. This expansion mechanism increases the gripping surface area and friction contact, thereby improving grip reliability on stuck fasteners without requiring a completely complex tool structure
Solution Approach 2:
The patent applies the nesting principle by placing the cam mechanism and jaw components within the hollow body structure. The cam portion is received within a receptacle in the body, and the jaw can be inserted through an opening in the body. This nested arrangement allows the expansion mechanism to be contained within the tool's overall structure, maintaining relatively simple external dimensions while incorporating functional complexity internally
2Force
If the drive flanks are made larger to improve engagement, then the grip strength increases, but the tool cannot engage fasteners with standard-sized sockets
Solution Approach 1:
The expandable jaw mechanism allows the tool to adapt its engagement surface size dynamically. In the contracted state, the jaw has a smaller external dimension that can engage with standard-sized sockets. When expanded, the jaw presents a larger gripping surface area that increases friction and grip strength on stuck fasteners. This dynamic size adjustment resolves the contradiction between engagement size and grip strength
Solution Approach 2:
The patent applies local quality by concentrating the increased gripping surface area specifically at the jaw's engagement surface with the fastener, while keeping the rest of the tool structure compact. The jaw's external surface that contacts the fastener is designed to expand and provide increased friction contact locally, without requiring the entire tool to be oversized, thus maintaining compatibility with standard sockets
3Reliability
If the jaw is made expandable to improve engagement, then the grip reliability increases, but the device complexity increases due to additional components
Solution Approach 1:
The patent merges the cam mechanism and the jaw into a single integrated component. The cam portion and jaw are formed as one piece, eliminating the need for separate cam and jaw components. This integration reduces the number of parts while maintaining the expandable functionality, thereby improving engagement reliability without proportionally increasing device complexity
Solution Approach 2:
The patent segments the tool into distinct functional zones: the body with receptacle, the integrated cam-jaw component, and the drive flats. This segmentation allows each component to be optimized for its specific function while maintaining overall simplicity. The cam-jaw assembly can be manufactured as a single piece through processes like investment casting, reducing assembly complexity despite the added functionality
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 tool securely engages and rotates stuck fasteners by expanding to fit the fastener's socket, preventing slippage and allowing for effective loosening or tightening without drilling, thus addressing the issue of stuck fasteners.
Implementation Method 1
Each of the cam portions has a partly cylindrical outer surface that is received within one of the receptacles. Each of the cam portions has a pair of flat flanks that protrude inward from the opening of one of the receptacles. An increment of rotation of the body relative to the jaws causes the inner corners of the flanks to move outward from the axis and the outer surfaces of the engaging portions to move from a contracted position to an expanded position.
Data Source
AI summary
A tool has a body with an axially extending cavity containing partly cylindrical receptacles. Each receptacle has an opening facing inward toward the axis. A partly cylindrical cam portion of a jaw fits within each of the receptacles. Each jaw has a workpiece engaging portion protruding from the body. Each of the cam portions has a pair of flat flanks that protrude inward from the opening of one of the receptacles. The flat flanks intersect each other at an inner corner. Each flank abuts one of the flanks of another of the cam members. Each of the engaging portions has an outer surface configured to engage a hole within the workpiece. An increment of rotation of the body relative to the jaws causes the inner corners of the flanks to move outward from the axis and the outer surfaces of the engaging portions to move from a contracted position to an expanded position.