Telescopic Prop Thread Protection via Axial Spacing
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Solution Overview
Problem
Push-pull props in the construction sector face contamination and mechanical damage issues, leading to malfunction and excessive thread wear, particularly due to exposure to fresh concrete and unavoidable mechanical loads during operation.
Innovation Solution
The internal thread is protected by being axially spaced from the edge section with a reduced passage cross-section, featuring a concentric reduction and potential conical or stepped taper, combined with an axially arched outer jacket surface and a sealing element to prevent contaminant ingress, while eliminating costly welding and machining, and enhancing ergonomic handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the internal thread is positioned at the edge section of the outer tube, then the thread engagement is achieved, but the thread is exposed to contamination from fresh concrete and mechanical damage during operation and transport
Solution Approach 1:
The internal thread is moved from the traditional edge section position to an intermediate position along the outer tube's length. This spatial repositioning in the axial dimension protects the thread from direct exposure to contaminants and mechanical damage while maintaining its engagement function with the threaded rod.
Solution Approach 2:
The edge section acts as an intermediary protective element between the external environment and the internal thread. By reducing the passage cross-section at the edge section, it creates a protective barrier that prevents contaminants from reaching the thread while allowing the thread to function normally at its protected position.
2Reliability
If the internal thread is produced by welding a threaded nut onto the outer tube, then thread engagement is achieved, but cost-intensive welding work and potential thread wear are incurred
Solution Approach 1:
The production of the internal thread is merged with the production of the outer tube itself. The internal thread is formed directly during tube manufacturing through embossing or machining, eliminating the separate welding operation for attaching a threaded nut. This integration reduces manufacturing steps, costs, and potential failure points.
Solution Approach 2:
The outer tube is designed to serve multiple functions: it provides structural support, defines the passage cross-section, and directly carries the internal thread formation. This multi-functionality eliminates the need for separate components like welded nuts, simplifying the overall structure and manufacturing process.
3Reliability
If the passage cross-section of the edge section is reduced concentrically, then protection against contamination and mechanical damage is improved, but the load-bearing capacity may be affected
Solution Approach 1:
The load path is redirected from the reduced edge section to the stronger intermediate region where the internal thread is positioned. By moving the thread axially away from the edge, the structural load is transferred to the full-cross-section portion of the tube, while the edge section's reduced cross-section serves only its protective function.
Solution Approach 2:
The outer tube is functionally segmented into different zones: the edge section with reduced cross-section for protection, the intermediate section with full cross-section for load bearing, and the thread engagement zone. This segmentation allows each section to be optimized for its specific function without compromising overall performance.
Data Source
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AI summary
The invention relates to a telescopic push-pull prop (10) for the construction field, having an outer tube (12) and having at least one threaded rod or inner tube (14) disposed axially adjustable therein. An outer thread (22) of the inner tube (14) engages with an inner thread (24) of the outer tube (12). According to the invention, the inner thread (24) of the outer tube (12) is disposed at an axial distance from a free end (26) of the outer tube (12) associated with the inner tube (14), wherein the inner thread (24) of the outer tube (12) is produced by an at least partially circumferential reduction of the outer tube (12) over a mandrel positioned in the outer tube (12), wherein said mandrel comprises an external thread. The outer tube (12) comprises an edge section (34) at the free end (26) thereof having a reduced pass-through cross section (32') relative to a nominal width (36) of the outer tube.