Lifting Lug Support Bolt Locking for Tool-Free Sling Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing connection devices for coupling loads to lifting lugs are complex, difficult to assemble, and cannot easily accommodate closed slings or ensure tool-free assembly, leading to issues with orientation and potential unscrewing of the support bolt under heavy loads.
Innovation Solution
A connection device featuring a ring holder with a ball bearing support for the support bolt, a sleeve with a radially protruding end flange for covering the ring holder, and tilting lever locking members that can be manually activated without tools, allowing for easy orientation and secure locking of the support bolt.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If locking members are provided to block the bolt head in rotation, then relatively large torques can be transmitted by the lifting lug, but the support bolt cannot be oriented in the load direction and may become unscrewed
Solution Approach 1:
The locking member is designed to be movable between a locked position (blocking rotation) and an unlocked position (allowing rotation). This dynamic state change enables the bolt to be oriented during installation, then locked to transmit torque, resolving the contradiction between orientation capability and torque transmission
2Adaptability or versatility
If the lifting lug is constructed as an open ring, then closed slings can be suspended, but the overall construction becomes complex and installation becomes difficult
Solution Approach 1:
The connection device is divided into separable components: the lifting lug (open ring), the ring holder, and the support bolt assembly. This segmentation allows the lifting lug to maintain its simple open ring structure for sling installation, while the ring holder provides the necessary mounting functionality, reducing overall construction complexity
3Ease of operation
If the support bolt is rotatable relative to the lifting lug, then orientation in load direction is enabled, but significant friction forces occur and wear increases under heavy loads
Solution Approach 1:
The system transitions from a permanently rotatable connection to a dynamically controlled one: initially rotatable for orientation, then locked to prevent rotation under load. This eliminates continuous friction and wear while preserving the necessary orientation capability during installation
4Reliability
If a separate tool is required to activate locking members, then precise locking is achieved, but assembly time and complexity increase
Solution Approach 1:
The locking member is designed to be manually operable without tools. The operator can directly manipulate the locking member (e.g., sliding it along the bolt or rotating it into position) to engage or disengage the lock, achieving precise locking while eliminating tool requirements and reducing assembly time
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 connection device enables simple, tool-free assembly and the installation of closed slings, while providing secure rotational blocking and easy orientation of the support bolt, even under heavy loads, with minimal friction and risk of unscrewing.
Implementation Method 1
the support bolt being supported in the through-opening of the ring holder by means of a ball bearing
Data Source
AI summary
A connection device for coupling a load to a lifting lug with a support bolt which is rotatable in a through-opening of a ring holder. The support bolt has a threaded shaft and a bolt head which protrudes radially, and which can also be rotated therewith relative to the lifting lug. The ring holder is covered at the lower side thereof by an end flange at the lower end of a sleeve which is releasably secured to the support bolt by tension in an axial direction. The ring holder has at least one locking member for the bolt head which blocks the bolt head from rotation in a locking position and which is not in engagement with the bolt head in an initial position. The support bolt is supported in the through-opening of the ring holder with a ball bearing, and the lifting lug is an open ring.