Push-Button Shaft Coupler With Flat Bore Floor to Prevent Jams
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Solution Overview
Problem
Existing couplers for connecting shaft segments suffer from button jams, leading to failure, and their manufacturing is costly due to the use of metal materials and complex machining processes.
Innovation Solution
A push-button shaft coupler design featuring a male half coupler with a flat inner bore floor and a button travel limiter, allowing for economical injection molding and improved assembly, which includes a spring block or buttresses to prevent button jams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal bar stock is used for coupler halves with lathe-turning, drilling, and milling, then manufacturing precision and reliability are improved, but manufacturing cost and complexity increase
Solution Approach 1:
The patent replaces expensive metal coupler halves with inexpensive plastic injection-molded coupler halves. The plastic material (such as glass fiber filled Nylon 66) provides sufficient durability for the application while dramatically reducing material cost and eliminating complex machining operations like lathe-turning, drilling, and milling.
Solution Approach 2:
The patent changes the material parameter from metal to plastic, enabling injection molding as the manufacturing process. This parameter change allows the coupler halves to be produced through simple injection molding without expensive secondary machining operations, while maintaining the structural integrity needed for reliable operation.
2Manufacturing precision
If complex mold parts and secondary operations are used to replicate machined male coupler body, then manufacturing precision is maintained, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent incorporates the button travel limiter feature directly into the injection mold cavity design, so the限位 structure is formed during the primary molding process. This preliminary action eliminates the need for secondary machining operations and complex movable mold parts, achieving both geometric precision and manufacturing simplicity.
Solution Approach 2:
The patent uses a simple, stationary injection mold design that produces plastic coupler halves with integrated features. This approach replaces complex movable mold parts and secondary machining operations with a straightforward molding process that achieves the required precision without adding device complexity.
3Reliability
If drilled spring seats are used to reduce button jams, then button reliability is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the button travel limiter function with the coupler half body structure itself. The限位 feature is integrated into the injection-molded plastic body, eliminating the need for separate drilled spring seats or additional components. This integration maintains button reliability while reducing manufacturing cost and complexity.
Solution Approach 2:
The patent uses the injection molding process to directly form the button travel limiter feature in the plastic coupler half body. This approach replaces expensive drilled spring seats with a cost-effective molded-in feature, achieving the same reliability benefit at lower manufacturing cost.
4Volume of moving object
If small interior bore space is used in male coupler halves, then compactness is improved, but assembly difficulty increases due to difficulty in inserting pushbutton and spring
Solution Approach 1:
The patent designs the injection mold to directly form the button travel limiter and spring seat features during the primary molding process. This preliminary action ensures proper positioning and geometry of internal features, making subsequent assembly of the pushbutton and spring much easier despite the compact bore space.
Solution Approach 2:
The injection-molded plastic coupler half body self-provides the button travel limiter and spring seat features through its molded geometry. This self-service approach eliminates the need for additional machining or assembly steps to create these features, simplifying the overall assembly process while maintaining compact dimensions.
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 design enables cost-effective production and reliable operation by preventing button jams while maintaining functionality, using injection molding and simplified assembly processes.
Implementation Method 1
The push button is urged radially outwardly through the opening by the spring that extends from a recess in the button to the button travel limiter
Data Source
AI summary
A single-button coupler comprises a female half coupler and a mating male half coupler that has an injection molded plastic body. The body of the male half coupler has a lengthwise bore. The outer section of the bore is substantially circular, for attachment of a round shaft. The inner section of the bore has a radial opening to the body exterior, within which the button sets. The inner bore section at least has a flat floor, upon which sets the base of the spring that actuates the button. The flat floor preferably runs the whole length of the bore. A button travel limiter adjacent the wall at the end of the inner section of the bore helps locate the spring upon the flat floor during assembly. The button travel limiter stops a user from pushing the button into the inner bore to jam the button.