Impact Tool Drive Assembly for High Torque Fastening
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Solution Overview
Problem
Existing impact tools struggle to deliver high torque efficiently for tasks such as loosening stuck fasteners, as they often require manual effort and lack the capability to produce sufficient rotational impacts.
Innovation Solution
The impact tool features a drive assembly with a camshaft, an anvil, and a hammer that is both rotationally and axially movable, biased by a spring, capable of converting continuous torque from an electric motor into consecutive rotational impacts, with adjustable modes for varying impact rates and a large anvil lug for enhanced torque transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If existing impact tools are used, then they can provide some torque, but they cannot deliver sufficient high torque (at least 1,700 ft-lbs) efficiently for loosening stuck fasteners
Solution Approach 1:
The hammer is designed to be both rotationally and axially movable relative to the anvil, allowing dynamic adjustment of impact orientation. The spring biases the hammer axially toward the anvil while camshaft rotation enables rotational movement, creating variable impact angles that optimize torque delivery for stuck fasteners
Solution Approach 2:
The camshaft converts continuous rotational motion into periodic impact events. As the camshaft rotates, it periodically drives the hammer into the anvil, creating consecutive rotational impacts at controlled rates (at least 2 impacts per revolution in first mode, or at least 1 impact per revolution in second mode), delivering high torque in repeated cycles
2Force
If manual effort is used to loosen stuck fasteners, then some torque can be applied, but it requires excessive manual effort and cannot achieve sufficient torque capacity
Solution Approach 1:
The electric motor replaces manual mechanical input entirely. The motor provides continuous rotational torque that drives the camshaft, which in turn drives the hammer-anvil impact mechanism. This substitution eliminates the need for manual effort while delivering torque capacity of at least 1,700 ft-lbs through the impact mechanism
Solution Approach 2:
The camshaft acts as an intermediary between the electric motor's continuous rotation and the hammer's impact motion. It converts the motor's smooth rotational torque into the periodic, high-force impact movements needed for loosening stuck fasteners, while the spring provides additional mechanical assistance by biasing the hammer toward the anvil
3Adaptability or versatility
If standard impact tools are used, then they can provide basic torque, but they lack adjustable impact modes for varying operational requirements
Solution Approach 1:
The adjustment mechanism allows the second handle to be repositioned, which changes the operational characteristics of the drive assembly. This dynamic adjustability provides at least two operating modes: first mode delivering at least 2 impacts per camshaft revolution, and second mode delivering at least 1 impact per camshaft revolution, enabling adaptation to different fastening or loosening requirements
Solution Approach 2:
The single drive assembly with hammer and anvil serves multiple functions through its adjustable modes. It can operate in a high-frequency mode (2+ impacts/revolution) for general fastening tasks, or in a lower-frequency mode (1+ impact/revolution) for breaking stuck fasteners, making the tool versatile for different applications without requiring multiple separate mechanisms
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 achieves at least 1,700 ft-lbs of fastening torque with adjustable impact modes, allowing for efficient loosening of stuck fasteners with reduced manual effort and increased torque capacity compared to standard tools.
Implementation Method 1
The drive assembly includes a spring for biasing the hammer in an axial direction toward the anvil
Implementation Method 2
The drive assembly includes a camshaft operably coupled to the electric motor, an anvil rotatable about an axis, and a hammer that is both rotationally and axially movable relative to the anvil for imparting the consecutive rotational impacts upon the anvil. The hammer is axially movable along the camshaft
Data Source
AI summary
An impact tool includes a housing with a first and second housing portions and a first handle extending from the first housing portion, a motor supported in the housing, a battery receptacle is located at a bottom end of the first handle, and a battery pack removably coupled to the battery receptacle to provide power to the motor. The impact tool also includes a trigger located on the first handle to selectively energize the motor, a gear assembly, and a drive assembly for converting a continuous torque input from the motor to consecutive rotational impacts upon a workpiece such that the drive assembly is capable of developing at least 1,700 ft-lbs of fastening torque. A gear support is coupled to the first housing portion and the second housing portion and defines a gear case with the second housing portion to enclose the gear assembly and the drive assembly.