Surgical Saw Blade Bar Laser Welding Deformation Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing of surgical saw blades with a static blade bar and a pivoting head is economically impractical due to expensive machining processes and potential curvature issues that lead to deviation in cutting paths and wear on cutting guides.
Innovation Solution
A method involving progressive punch forming to create a cylindrical pivot boss and laser welding of blade bar plates to minimize deformation and ensure straightness, reducing material wear and curvature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If machining is used to form the blade bar, then the pivot boss can be precisely formed, but the manufacturing cost becomes economically impractical
Solution Approach 1:
The patent replaces traditional mechanical machining processes with progressive punch forming to create the pivot boss. This forming process uses controlled plastic deformation through multiple punching stages to achieve the desired cylindrical shape and surface finish without expensive CNC machining operations, thereby reducing manufacturing costs while maintaining precision requirements.
Solution Approach 2:
The patent changes the manufacturing parameters by transitioning from subtractive machining to formative punching processes. By controlling the punching depth, force, and progression through multiple stages, the method achieves the required geometric precision and surface quality of the pivot boss through material deformation rather than material removal, making the process economically viable.
2Ease of manufacture
If welding is used to assemble the blade bar plates, then the blade bar can be constructed from multiple plates, but deformation and curvature may occur
Solution Approach 1:
The patent applies preliminary counter-bending to the blade bar plates before welding to anticipate and compensate for the deformation that will occur during the welding process. By pre-positioning the plates in a slightly curved state that will straighten upon welding completion, the final assembled blade bar achieves the required straightness and geometric accuracy without excessive post-weld correction.
Solution Approach 2:
The patent employs preliminary anti-action by applying counter-forces or counter-deformations to the blade bar plates before welding. This involves pre-bending the plates in the opposite direction of the expected welding-induced curvature, so that when welding occurs and thermal expansion/contraction causes deformation, the blade bar ends up straight or close to straight, eliminating the need for expensive post-weld straightening operations.
3Ease of manufacture
If the pivot boss surface is rough, then manufacturing is easier, but wear concentrates on specific points causing component failure
Solution Approach 1:
The patent applies local quality by ensuring the pivot boss has a uniformly smooth cylindrical surface finish through controlled progressive punching. Each punching stage progressively refines the surface quality, and the final punch creates a polished-like finish in the critical bearing area. This localized surface quality control ensures even distribution of contact pressure and wear across the entire pivot boss surface, preventing stress concentration and component failure.
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
This method reduces material deformation and curvature, enhancing the surgical saw blade's precision and longevity by minimizing wear and heat generation, thus improving cutting accuracy and reducing guide material wear.
Implementation Method 1
the pivot boss is progressively formed in one of the plates forming the pivot boss
Implementation Method 2
the plates forming the blade bar are welded in a selected pattern to substantially eliminate the deformation of the plates due to the welding process
Data Source
Figure 1
Figure 2
Figure 3~13A
AI summary
In a method of assembling an surgical saw blade assembly (40) with an blade bar (44) that contains an oscillating head (46) the blade bar is formed from opposed plates (54, 56). One of the plates is punch stamped to define the boss (74) around which blade head pivots. The plates are welded together in a series of steps wherein spaced apart sections of the plates are welded together.