Impact-Compensating Bucking Bar for Riveting Vibration Reduction
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Solution Overview
Problem
Riveting tool operators experience high levels of hand-transmitted vibration (HTV) due to the transfer of impact forces during riveting, leading to conditions such as hand-arm vibration syndrome (HAVS) and musculoskeletal disorders, as existing bucking bars do not effectively dissipate the impact stresses.
Innovation Solution
The introduction of impact-compensating bucking bars featuring a compensating inertial mass coupled to the body by a flexible and resilient mass support, which allows translation parallel to the strike axis while preventing movement orthogonal to it, and an optional mass actuator activated by a strike detector to dissipate energy and reduce user impact stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a traditional solid bucking bar is used to transfer impact forces during riveting, then the rivet tail can be effectively upset and hardened, but high levels of hand-transmitted vibration are transferred to the operator's hand causing hand-arm vibration syndrome and musculoskeletal disorders
Solution Approach 1:
The bucking bar is segmented into distinct functional zones: a rigid distal portion for effective rivet upsetting, a resilient intermediate portion for vibration attenuation, and a proximal portion for user comfort. This segmentation allows each section to perform its specific function optimally without compromising the others.
Solution Approach 2:
The resilient material portion is positioned between the impact zone and the user's hand to beforehand cushion and absorb vibration energy before it reaches the operator. This proactive vibration management prevents hand-transmitted vibration from causing harm while maintaining rivet upsetting effectiveness.
2Productivity
If the bucking bar body is made more rigid to improve impact force transmission for rivet upsetting, then the riveting process becomes more efficient, but the vibration and impact stresses transmitted to the user's hand increase
Solution Approach 1:
The bucking bar is divided into rigid and resilient sections, allowing the distal portion to efficiently transmit impact forces for productive rivet upsetting while the resilient intermediate portion isolates the user from harmful vibrations and impact stresses.
Solution Approach 2:
The resilient material portion acts as an intermediary element between the rigid bucking bar body and the user's hand, mediating the transmission of vibrations and impact stresses by absorbing and dissipating energy while allowing necessary mechanical function to continue.
3Object-affected harmful factors
If the bucking bar is designed with vibration-damping materials to reduce hand-transmitted vibration, then user comfort and health are improved, but the effectiveness of impact force transmission to the rivet tail may be reduced
Solution Approach 1:
The bucking bar features a segmented design where the distal portion maintains rigidity for effective impact force transmission to upset the rivet tail, while the intermediate resilient portion provides vibration damping without interfering with the primary upsetting function.
Solution Approach 2:
Different portions of the bucking bar have different material properties optimized for their specific functions: the distal portion is rigid for force transmission, while the intermediate portion is resilient for vibration attenuation, creating local quality variations that resolve the contradiction.
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 described bucking bars effectively dissipate impact energy, reducing the transmission of vibrations to the user's hand and minimizing the risk of hand-arm vibration syndrome and musculoskeletal disorders, with both passive and active compensation methods available to manage repetitive impact forces.
Implementation Method 1
a compensating inertial mass coupled to the body by a flexible and resilient mass support that permits translation of the compensating inertial mass parallel to the strike axis
Implementation Method 2
hand-transmitted vibration (or HTV) has been associated with the development of hand-arm vibration syndrome (HAVS)
Implementation Method 3
a flexible and resilient mass support that permits translation of the compensating inertial mass parallel to the strike axis
Data Source
AI summary
An impact-compensating bucking bar and its use to reduce impacts during riveting, where the bucking bar includes a body; a strike surface on a distal portion of the body, a compensating inertial mass coupled to the body by a flexible and resilient mass support, and a handgrip coupled to the body and configured for the user to urge the strike surface of the bucking bar against a tail of a rivet to facilitate upsetting the rivet tail during riveting. A relative movement of the compensating inertial mass of the bucking bar in response to a strike on the rivet head at least partially dissipates energy imparted to the body during riveting, reducing impact stresses on the bucking bar user.