Pipe Threading Die Head Friction Locking for Stable Cam Plate Position
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Powered pipe threading machines face challenges in securely locking the rotational position of the cam plate relative to the die carrier, leading to potential loosening during thread cutting operations, which can result in inconsistent thread quality and increased user effort due to the need for additional tools like cheater bars.
Innovation Solution
The implementation of a locking system that includes a positioning screw extending through an arcuate slot in the cam plate, a bushing with a flange portion, and a handle threadably coupled to the positioning screw, which develops a frictional force to lock the rotational position of the cam plate relative to the die carrier, eliminating the need for additional tools and ensuring secure clamping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional locking system with a positioning screw and lock lever is used, then the device structure is simple, but the locking reliability is insufficient leading to potential loosening during thread cutting operations
Solution Approach 1:
The bushing is pre-installed on the positioning screw with a flange portion that will contact the cam plate. The arcuate slot is pre-formed in the cam plate to guide the positioning screw. These preliminary preparations ensure that when the handle is rotated, the locking action occurs immediately and reliably without requiring additional adjustment or tools.
Solution Approach 2:
The bushing acts as an intermediary component between the positioning screw and the cam plate. It transfers the rotational force from the handle to the positioning screw while its flange portion creates the frictional contact with the cam plate. This intermediary mechanism provides more reliable locking than direct screw-to-plate contact.
2Ease of operation
If additional tools like cheater bars are used to tighten the lock lever, then the clamping force is sufficient to prevent loosening, but the ease of operation deteriorates due to requiring additional tools and increased user effort
Solution Approach 1:
The solution moves from a linear tightening motion (rotating the lock lever) to a rotational motion (rotating the handle with the positioning screw). This dimensional change allows the user to apply force more effectively through the longer handle radius, generating sufficient clamping force without needing external tools like cheater bars.
Solution Approach 2:
The locking system transitions from a static lock lever that requires manual tightening to a dynamic handle that rotates to engage the threaded positioning screw. This dynamic action allows progressive engagement and self-amplifying force through the threading mechanism, making operation easier while maintaining sufficient clamping force.
3Manufacturing precision
If the cam plate rotational position is not securely locked, then the device complexity remains low, but the manufacturing precision deteriorates due to inconsistent thread quality from cam plate movement
Solution Approach 1:
The frictional force between the bushing flange portion and the cam plate surface acts as a cushioning mechanism that prevents unwanted movement or loosening during thread cutting operations. This pre-established frictional contact compensates for any potential movement before it can affect thread quality, ensuring consistent manufacturing precision.
4Ease of operation
If a friction-based locking mechanism is used instead of a traditional lock lever, then the ease of operation improves, but the reliability may worsen due to potential slippage under high load
Solution Approach 1:
The solution merges two locking mechanisms: the friction-based ease of operation from the handle rotation and the mechanical security of threaded engagement. The handle rotates to turn the positioning screw, combining the simplicity of friction engagement with the reliability of thread locking, preventing slippage under high load while maintaining ease of operation.
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
This solution enhances the security of the locking mechanism, preventing unintentional loosening during thread cutting, reducing user effort, and ensuring consistent thread quality without requiring additional tools like cheater bars.
Implementation Method 1
developing a frictional force between the bushing and the cam plate to lock the rotational position of the cam plate relative to the die carrier
Data Source
AI summary
A thread-cutting die head includes a die carrier, defining a central axis, for supporting a plurality of thread-cutting dies, a cam plate coaxial with the die carrier including a plurality of cam members for engaging with the plurality of thread-cutting dies, and a locking system including a positioning screw extending through an arcuate slot in the cam plate, a bushing surrounding the positioning screw, and a handle threadably coupled to the positioning screw configured to impart a force against the bushing to press the flange portion of the bushing against the first surface of the cam plate, thereby developing a frictional force between the bushing and the cam plate to lock the rotational position of the cam plate relative to the die carrier.