Commercial Vehicle Fastener Interference Fit Connection
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Solution Overview
Problem
Existing fasteners for commercial vehicle bodies, particularly doors, face challenges with connection stability and complexity, where non-permanent connections offer ease but lack stability, while permanent connections provide rigidity but are complex and potentially damaging, and existing solutions like rivets with bushings are expensive and unstable.
Innovation Solution
A fastener system featuring a rotating bar with engaging elements and an operating lever, utilizing a pin and locking collar with an interference fit through holes in the connecting bodies and bar, providing a stable and simple connection similar to welding without the complexity or expense.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If permanent connections (welding or rivets) are used to connect the operating lever or engaging elements to the rotating bar, then structural rigidity and connection stability are improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent changes the connection method from permanent (welding/rivets) to a controlled permanent connection using interference fit. The pin is inserted with interference fit into aligned holes of the bar and connecting body, creating a rigid connection without welding or rivets. This maintains connection stability while simplifying the connection process and reducing device complexity.
2Reliability
If welding is used to connect parts, then connection stability is improved, but the risk of damaging parts and increasing manufacturing complexity increases
Solution Approach 1:
The patent replaces the thermal process of welding with a mechanical interference fit connection. The pin is inserted with interference fit into precisely aligned holes, creating a rigid mechanical connection that avoids the harmful thermal effects of welding, such as heat-affected zones, distortion, and potential damage to adjacent parts.
3Ease of manufacture
If non-permanent connections are used to connect the operating lever or engaging elements to the rotating bar, then ease of assembly and no damage to parts are improved, but connection stability deteriorates due to play between parts
Solution Approach 1:
The patent changes the connection from non-permanent (loose fit) to a controlled permanent connection using interference fit. The pin dimensions are specifically designed to create interference with the holes in the bar and connecting body, eliminating play while maintaining ease of assembly through precise hole alignment and pin insertion.
4Reliability
If rivets with bushings are used to minimize play, then connection stability is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent extracts and eliminates the bushing element from the connection system. Instead of using rivets with bushings, the design uses a simple pin inserted with interference fit directly into aligned holes of the bar and connecting body. This reduces the number of connection elements while maintaining connection stability through the interference fit mechanism.
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 achieves a stable and cost-effective connection that is easy to produce and implement, ensuring the fastener's parts remain securely aligned without the drawbacks of prior art, such as play and increased movement over time.
Implementation Method 1
a pin (17) and a locking collar (18), characterised in that the connecting body (7, 11) comprises at least one main hole (13) extending along a first direction, and at least one first fixing through hole (14) extending transversally to the first direction and intersecting the main hole (13), and in that the bar (4) comprises at least one second fixing through hole (15) extending transversally to the longitudinal axis, which is positioned inside the main hole (13) of the connecting body (7, 11) and which is axially aligned with the first fixing hole (14), and in that the pin (17) connects the bar (4) and the connecting body (7, 11) through the first fixing through hole (14) and the second fixing hole (15) respectively
Data Source
Figure 1
Figure 2~3
Figure 4~9
AI summary
A fastener for the bodies of commercial vehicles, comprising a rotatable bar (4) on which there are non-rotatably mounted at least one engaging element (5) comprising a connecting body (7) fixed to the bar (4) and an engaging projection (8) engageable with a contact element (9), and an operating lever (6) also comprising a connecting body (11) fixed to the bar (4) and a handle (12), wherein at least one connecting body (7), (11) comprises a main hole (13) in which the bar (4) is inserted, and at least one first fixing through hole (14) intersecting the main hole (13), and the bar (4) comprises at least one second fixing through hole (15) axially aligned with the first fixing hole (14); a permanent coupling element (16) is also present, comprising a pin (17) constituted of a shank (19) comprising a first end (20) equipped with an enlarged head (21) and a second end (22) to which a locking collar (18) is rigidly connected, the shank (19) being inserted with interference fit both in the first fixing hole (14) and in the second fixing hole (15). A method for mounting the connecting body on the bar is also claimed.