Impact Tool Spindle Ball Mechanism for Cam-Out Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The cam-out phenomenon occurs when using impact tools, where the tool accessory slips out of the cruciform groove in the screw head during fastening or tightening operations, leading to reduced work efficiency.
Innovation Solution
The impact tool design includes a motor with a voltage of 18 V or more, a spindle with a groove, a ball held in the groove, a hammer supported by the ball, and at least one spring biasing the hammer forward. This configuration reduces the impact-start torque to 1,100 N·mm or less, thereby curbing the cam-out phenomenon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the impact-start torque is increased to improve fastening capability, then the tool can tighten screws more effectively, but the cam-out phenomenon occurs more frequently
Solution Approach 1:
The patent applies parameter changes by precisely controlling the impact-start torque to be 1,100 N·mm or less. This specific parameter threshold ensures that the hammer begins impacting the anvil at the optimal moment during screw tightening, preventing the tool accessory from slipping out of the cruciform groove while maintaining effective fastening capability.
2Reliability
If the impact-start torque is decreased to prevent cam-out, then the tool accessory remains engaged in the groove, but the fastening efficiency may be reduced
Solution Approach 1:
The patent implements preliminary action by ensuring the hammer starts impacting the anvil before the screw reaches a critical tightening stage. By controlling the impact-start torque threshold, the system proactively prevents cam-out from occurring in the first place, rather than reacting after the problem arises, thus maintaining both reliability and productivity.
3Reliability
If the impact mechanism is optimized to reduce impact-start torque, then cam-out is prevented, but the device complexity increases
Solution Approach 1:
The patent uses the ball as an intermediary element in the spindle groove to translate rotational motion into the reciprocating motion of the hammer. This mechanical intermediary allows the system to achieve precise control over impact-start torque through the interaction between the ball, spindle groove, and spring mechanism, without requiring complex electronic 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 effectively reduces the occurrence of the cam-out phenomenon by ensuring an earlier start of impact, which results in higher work efficiency during screw-tightening operations.
Implementation Method 1
at least one spring, which biases the hammer forward
Implementation Method 2
an anvil, which is impacted in a rotational direction by the hammer
Data Source
AI summary
An impact tool (1) includes: a motor (6) supplied with a voltage of 18 V or more; a spindle (8) rotated by the motor; a spindle groove (8D) formed in the spindle; a ball (48) held in the spindle groove; a hammer (47) supported on the spindle via the ball; a spring (49, 50), which biases the hammer forward; and an anvil (10) configured to be impacted in a rotational direction by the hammer. An impact-start torque, which is the torque acting on the anvil when the hammer starts to impact the anvil, is 1,100 N·mm or less.