Pull-up Bolt Assembly for Manway Covers
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Solution Overview
Problem
Existing devices for handling manway covers, which are often heavy and cumbersome, pose safety hazards due to inadequate support and secure attachment, requiring additional machining that can be costly and impractical in field settings.
Innovation Solution
A pull-up bolt assembly with a threaded shaft, tapered member, and radially expandable friction member that securely attaches to a hinge component without altering the manway cover or flange, providing frictional support and resisting pull-out forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional bolts and nuts are used to attach manway covers, then the attachment is simple and straightforward, but the bolts cannot provide adequate support for heavy covers and may fail under pull-out forces
Solution Approach 1:
The bolt assembly changes the physical state of the friction member from unexpanded to expanded, increasing its diameter and frictional contact with the cover and hinge device. This parameter change enables the bolt to resist pull-out forces and provide adequate support for heavy covers
Solution Approach 2:
The fastening system is divided into distinct functional components: the bolt member for insertion, the friction member for expansion and frictional engagement, the tapered member for facilitating expansion, and the nut for securing. This segmentation allows each component to perform its specific function effectively
2Reliability
If additional machining is performed on the manway cover or flange to improve attachment, then the attachment reliability improves, but the cost and time increase significantly
Solution Approach 1:
The friction member creates its own secure attachment through expansion and frictional engagement with the cover and hinge device. The system is self-contained and does not require external machining or modification of the cover or flange, enabling field installation without specialized equipment
Solution Approach 2:
The friction member acts as an intermediary between the bolt assembly and the manway cover, providing the necessary frictional force and mechanical engagement without requiring direct machining of the cover itself. This mediator enables reliable attachment while preserving the integrity of the cover and flange
3Force
If the bolt assembly uses high frictional force to secure the cover, then the resistance to pull-out forces improves, but the risk of damaging the cover or flange increases
Solution Approach 1:
The friction member is disposed around the bolt shaft and can expand radially outward to engage with the cover and hinge device. This nested configuration allows the friction member to apply frictional force uniformly around the bolt, securing the cover without concentrating stress at single points that could cause damage
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 solution safely supports and securely attaches manway covers to hinge devices without altering the structural integrity, addressing safety and practicality issues by providing a removable and reusable fastening system that resists shear and pull-out forces effectively.
Implementation Method 1
a radially expandable friction member disposed around the threaded shaft between the tapered member and the abutting member end... At least a portion of the expandable friction member expands outwardly in a radial direction... to frictionally supporting a high-weight structure
Implementation Method 2
a tapered member disposed around the threaded shaft between the nut component and the abutting member end... causing the expandable friction member to expand radially
Data Source
AI summary
A pull-up bolt assembly for frictionally supporting a high-weight structure to a hinge component using an opening or recess in the high-weight structure. The bolt assembly includes a pull-up bolt member having a threaded shaft with a first shaft end and a second shaft end, and an abutting member with a tapered surface formed at the first shaft end, the abutting member being wider than and tapering toward the threaded shaft, a nut component with an external torque-applying surface threadably connected to the threaded shaft, a tapered member with a tapered end portion and a flange formed between the external torque-applying surface of the nut component and the tapered end portion wherein the tapered end portion faces toward the tapered surface of the abutting member, and an expandable friction member disposed around the threaded shaft between the abutting member and the tapered member whereby the expandable friction member expands when the nut component is threadably moved toward the abutting member of the pull-up bolt member.