Conical Hitch Pin Lock Guard Against Torque-Based Theft

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Trailer hitch ball mount assemblies are susceptible to theft due to the ease with which conventional key locks can be defeated by applying torque or leverage, such as with a metal pipe, leading to the breakage of the hitch pin.

Innovation Solution

A hitch pin lock guard with a conically shaped exterior is used to cover the trailer hitch pin, preventing a metal pipe from gripping and applying torque to break the pin, by ensuring the cross-sectional area decreases away from the hitch, making it impossible for a thief to apply sufficient force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional key lock is used to secure the trailer hitch pin, then the locking function is provided, but the hitch pin can be easily defeated by applying torque or leverage with a metal pipe

Engineering Contradiction:

Improvesecurity of hitch pinVSAvoidvulnerability to torque application

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The lock guard features a conically shaped exterior surface that is curved rather than flat or angular. This curved surface prevents a metal pipe from gripping the hitch pin because the pipe cannot establish a stable friction interface on the tapered cone surface, eliminating the leverage mechanism needed to apply damaging torque to the pin or lock.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Ease of operation

If the hitch pin is exposed, then easy access for locking/unlocking is provided, but the pin is vulnerable to theft and damage

Engineering Contradiction:

Improveaccess to hitch pinVSAvoidexposure to theft

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The lock guard is a protective housing that encloses the key lock and hitch pin assembly. The hitch pin passes through the lock guard, with the key lock positioned within the guard's interior space. This nested arrangement protects the vulnerable components while maintaining functional access through the guard's opening.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Strength

If a metal pipe can grip the hitch pin, then leverage can be applied to break the pin, but the pin remains vulnerable until protected

Engineering Contradiction:

Improveresistance to breakingVSAvoidability to apply force

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The conically shaped lock guard is installed on the hitch pin before any theft attempt occurs. This preliminary protective measure creates a surface geometry that actively prevents the harmful action of gripping and leveragging. The tapered cone surface ensures that any attempt to apply force with a pipe results in slippage rather than force transmission, thereby preemptively neutralizing the threat.

Inventive Principle:

Principle #9Preliminary anti-action

Data Source

PatentUS20260061791A1Hitch pin lock guard

Publication Date: 2026.03.05 NELSON GARY L

AI summary

Disclosed are a method and device for securely attaching a trailer hitch ball mount assembly to a trailer hitch. In one application, a hitch pin lock guard may be shaped to fit over a trailer hitch pin while the trailer hitch pin is disposed through aligned holes of a trailer hitch and ball mount assembly. In an example, implementation, an exterior of hitch pin lock guard may be tapered so that a cross-sectional of the hitch pin lock guard decreases as the hitch pin lock guard extends away from the trailer hitch.