Bar Puller Eccentric Cam Spring Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bar pullers are limited in their ability to accommodate a wide range of billet sizes and weights due to linear spring mechanisms, which restrict their gripping force and adaptability, leading to inefficiencies and manual adjustments prone to errors.
Innovation Solution
A bar puller design featuring pivoting arms with an integral eccentric cam surface that compresses a urethane spring along a displacement curve increasing at a decreasing rate, allowing for robust gripping force adjustment across various billet sizes without manual adjustments, combined with friction-loaded end effectors for stable engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If linear spring mechanisms are used in bar pullers, then the structure is simple, but the gripping force and adaptability are restricted
Solution Approach 1:
The patent changes the spring mechanism from linear to radial operation, allowing the spring to expand and contract in multiple directions. This parameter change enables the bar puller to adapt to various billet sizes and weights while maintaining sufficient gripping force, resolving the contradiction between adaptability and structural simplicity.
Solution Approach 2:
The invention introduces a dynamic adjustment mechanism where the bar puller can automatically adjust its gripping force based on the billet characteristics. The radial spring mechanism allows for continuous adaptation during operation, eliminating the need for manual adjustments and improving versatility without significantly increasing complexity.
2Adaptability or versatility
If manual adjustments are made for different billet sizes, then adaptability is improved, but time loss and errors increase
Solution Approach 1:
The bar puller is designed to automatically adjust and accommodate different billet sizes without manual intervention. The radial spring mechanism self-regulates based on the billet dimensions, eliminating the time-consuming manual adjustment process while maintaining high adaptability across various billet types.
Solution Approach 2:
The invention incorporates preliminary positioning features that guide the billet into the correct position before gripping occurs. This preliminary action ensures that the bar puller is pre-configured for the specific billet size, eliminating the need for time-consuming manual adjustments and reducing errors.
3Ease of operation
If linear spring expansion is used, then the mechanism is simple, but the ability to open sufficiently to receive bar and maintain clamping force is compromised
Solution Approach 1:
The patent transitions from linear to radial spring operation, creating a dynamic mechanism that can both open sufficiently to receive the bar and maintain clamping force during pulling. The radial expansion allows greater opening distance while the spring geometry ensures adequate clamping force is maintained throughout the operation.
Solution Approach 2:
By changing the spring operation from linear to radial, the invention alters the mechanical parameters of the system. This parameter change enables the spring to provide both the necessary opening distance for bar reception and the sustained clamping force required for effective pulling, improving 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
Enables automatic gripping and positioning of elongated workpieces across a wide range of sizes with consistent gripping force, reducing manual errors and increasing efficiency in manufacturing processes.
Implementation Method 1
a urethane spring in a spring chamber, where the cup can be contacted to raise it and compress the spring
Implementation Method 2
friction-loaded end effectors for stable engagement
Implementation Method 3
pivoting arms with an integral eccentric cam surface that compresses a urethane spring
Implementation Method 4
an integral eccentric cam surface that compresses a urethane spring along a displacement curve
Data Source
AI summary
In a bar puller, pins mount serrated rollers to pivoting arms, which are mounted by additional pins to a bar puller body. The body houses movable cups positioned to compress springs in response to pivoting motion of the pivoting arms. A cover retains the springs and cups in the body. In a manufacturing process where elongated stock material needs to be positioned automatically, such as in a CNC turning center, the bar puller manipulates the elongated material in the machine by holding it rigidly so that the bar puller can move the elongated material on the axis of elongation. This is accomplished by forcing the end effectors over the material, which separates the end effectors by pivoting the arms. The geometry of the pivoting arms causes interaction with the cups and springs to generate an opposing spring force to separate the end effectors.