Motorized Drawer Locking With Planetary Gears and No Position Control
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Solution Overview
Problem
Conventional drawer apparatuses in POS systems require position control and motor stop control for accurate operation, increasing complexity and cost, and are not suitable for silent environments due to metallic sounds and power supply limitations.
Innovation Solution
A drawer apparatus using a motor with a planetary gear system that allows locking and unlocking without position control or motor stop control, utilizing a hook and lock mechanism where the lock is released by unidirectional motor rotation, eliminating the need for sensor detection and reverse motor control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a solenoid actuator is used to lock and unlock the drawer, then the locking mechanism can be actuated, but metallic collision sounds are generated and power supply more than around 5V is required
Solution Approach 1:
The patent replaces the solenoid actuator with a DC motor that drives a planetary gear mechanism. This mechanical substitution eliminates the metallic collision sounds generated by solenoid plunger impact while maintaining the locking/unlocking function. The motor-driven gear system provides smooth operation without sharp mechanical impacts.
Solution Approach 2:
The patent changes the power supply parameter from requiring more than 5V (solenoid requirement) to compatible with USB bus power supply (5V). The DC motor and planetary gear mechanism can be actuated with lower power, enabling use with standard USB power sources.
2Manufacturing precision
If position control and motor stop control are implemented for accurate cam positioning, then the locking and unlocking can be controlled, but the device complexity and cost increase
Solution Approach 1:
The planetary gear mechanism automatically positions itself through its inherent mechanical structure. The gear teeth engagement and the ratchet mechanism provide self-limiting motion that naturally stops at the correct positions without requiring external sensors or control systems. The mechanism serves itself by using mechanical constraints to achieve precise positioning.
Solution Approach 2:
The patent uses a dynamic planetary gear mechanism where the relative positions of gears are determined by their rotational speeds and gear ratios rather than fixed positional control. The motor rotates at a constant speed, and the gear mechanism dynamically distributes this motion to achieve the required positioning through mechanical advantage and gear tooth engagement.
3Ease of operation
If a cylindrical cam with position control is used for locker rotation, then the lock can be released from the stopper, but sensors and control boards are required increasing cost
Solution Approach 1:
The patent replaces the cylindrical cam mechanism with a planetary gear system that achieves the same locker rotation function. The planetary gears provide the necessary rotational motion to the lock mechanism through pure mechanical advantage, eliminating the need for sensors to detect cam position or control boards to manage the rotation sequence.
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
Simplifies the operation by eliminating the need for position control and motor stop control, reducing costs and enabling silent operation by using a spring to shift gears, thus reducing the number of components and avoiding metallic sounds.
Implementation Method 1
A drawer apparatus using a motor with a planetary gear system that allows locking and unlocking without position control or motor stop control
Implementation Method 2
utilizing a hook and lock mechanism where the lock is released by unidirectional motor rotation, eliminating the need for sensor detection and reverse motor control
Data Source
AI summary
A drawer apparatus capable of locking and unlocking a drawer without position control and motor stop control is provided. A lock frame is released from the hook to be brought into an operable state by unidirectional rotation of a DC motor in an engaged state. A drawer is released from an anchor to be advanced out of the retracted position when the lock frame operates. A planetary gear unit is pushed by the lock frame. A small-diameter planetary gear is thereby shifted from the engaged state to a default state. The anchor is engaged with the drawer when the advanced drawer is pushed back to the retracted position. The hook is engaged with a lock when the advanced drawer is pushed back to the retracted position.