Drain Rod Connectors With Non-Circular Locking Threads

The patent employs asymmetric thread profiles where the male and female threads have non-circular cross-sections that are complementary to each other. This asymmetric design creates a mechanical interlock that prevents loosening during operation while still allowing manual assembly and disassembly. The asymmetric geometry ensures that the threads engage in a way that resists reverse rotation without requiring additional locking mechanisms or tools.

The connection system incorporates a dynamic element where the threaded fittings transition from a loose state during assembly to a locked state during operation. The non-circular thread profiles engage progressively as the rods are screwed together, creating increasing mechanical interference that naturally prevents loosening. This dynamic engagement provides both ease of initial assembly and reliable connection stability without requiring tools for tightening.

The threaded fittings are designed to be self-limiting in their tightening force. The non-circular thread profiles create a natural mechanical stop where the threads engage fully and lock together, preventing any possibility of overtightening. The asymmetric geometry ensures that once the threads are properly engaged, any additional force is distributed evenly and cannot exceed the design limits, eliminating the risk of fitting damage that would occur with tool-assisted tightening.

The connection system incorporates preliminary design features that prevent overtightening before it can occur. The non-circular thread profiles are engineered with specific geometric constraints that limit the maximum engagement depth and force. These preliminary design considerations ensure that manual tightening naturally stops at the optimal point, preventing the harmful effects of overtightening while achieving reliable connection stability.

The patent maintains simplicity by using a basic threaded connection form but improves reliability through asymmetric non-circular thread profiles. This asymmetric design creates a mechanical interlock that prevents loosening during the twisting and pulling forces of cleaning operations, while still maintaining the simplicity of a direct threaded connection without additional locking mechanisms, washers, or complex fastening systems.

The connection system changes the geometric parameters of the threaded profiles from conventional circular cross-sections to non-circular asymmetric shapes. This parameter change fundamentally improves the anti-loosening properties during operation while maintaining the overall simplicity of the connection mechanism. The modified thread geometry provides inherent mechanical locking without adding complexity to the assembly or disassembly process.