Electronic Lock Box with Acme Drive Screw and Two-State Latching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic lock boxes face vulnerabilities to attacks using simple tools and external forces, and they inefficiently use battery power due to high power consumption and frictional losses in their mechanical systems.
Innovation Solution
The design incorporates a two-state locking system with sloped surfaces and blocking members that provide enhanced security against external forces and a high drive ratio using an Acme drive screw to minimize friction and optimize power usage, allowing the lock box to operate effectively in low battery conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a traditional spur gear motor system is used to drive the movable actuator, then the device can operate with simple mechanics, but it suffers from high frictional losses and excessive power consumption
Solution Approach 1:
The patent replaces the traditional spur gear mechanical transmission system with an Acme power screw mechanism. This substitution eliminates the high-friction gear teeth engagement and uses a threaded screw that converts rotational motion to linear motion with significantly reduced frictional losses, directly addressing the energy efficiency problem
Solution Approach 2:
The patent changes the mechanical parameters of the drive system by using an Acme thread profile with specific lead and pitch dimensions. This parameter change optimizes the mechanical advantage and reduces the friction coefficient compared to gear systems, enabling lower power consumption while maintaining the required driving force
2Reliability
If a single-state latch system is used, then the device structure remains simple, but it provides insufficient security against attacks using simple tools and external forces
Solution Approach 1:
The patent divides the latching system into two distinct functional states: a first state for normal operation and a second state for enhanced security. This segmentation allows each state to be optimized for its specific purpose while maintaining overall system manageability despite the increased complexity
Solution Approach 2:
The patent implements a dynamic latching system where the movable actuator can be positioned at different locations to achieve different locking states. The system transitions between states based on operational requirements, providing adaptability and enhanced security without requiring a completely static complex structure
3Force
If the movable actuator uses perpendicular sloped surfaces, then the mechanical advantage is maximized, but it creates excessive friction and requires more power to operate
Solution Approach 1:
The patent changes the angular parameter of the sloped surfaces from perpendicular (90 degrees) to non-perpendicular angles. This parameter modification reduces the normal force between contacting surfaces, thereby reducing friction while maintaining sufficient mechanical advantage for the latching function
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 enhanced security and power efficiency result in greater resistance to unauthorized access and prolonged battery life, even in extreme cold conditions, without significant cost increases.
Implementation Method 1
a high drive ratio using an Acme drive screw to minimize friction and optimize power usage
Implementation Method 2
a movable actuator having first and second spaced-apart pairs of sloped surfaces
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
An electronic lock box contains a mechanical structure that allows the lock box to work in several different mechanical states. A first state is a key compartment door unlocking state, while a second state is a shackle release state. A third state is a 'soft lock' state, which allows the key compartment door to be closed, or the shackle to be re-installed, and once this has occurred, the door will not fall open, and the shackle will not fall out. A fourth state is a 'hard lock' state in which the key compartment door and the shackle are not easily disturbed by vibration or intentional impact by a would-be thief, who is attempting to unlawfully open the door or remove the shackle.