Motorized Pull-Out Cupboard Fitting With Spindle-Assisted Retraction
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Solution Overview
Problem
Existing pull-out fittings for cupboards either rely solely on manual operation, which is cumbersome when heavily loaded, or use electric motor drives that become inoperative if the motor fails, disrupting smooth operation and accessibility.
Innovation Solution
A pull-out fitting with an electric motor drive that assists in overcoming the retraction force, allowing for smooth operation even when heavily loaded, and includes a threaded spindle mechanism that automatically retracts once the maximum extended position is reached, with a delay circuit to prevent unintended retraction and activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an electric motor drive is used to assist manual operation of the pull-out frame, then ease of operation is improved, but device complexity increases
Solution Approach 1:
A threaded spindle mechanism serves as an intermediary between the electric motor drive and the pull-out frame. The motor rotates the spindle, which converts rotational motion to linear extension motion, assisting the user in pulling out the frame against the retraction device's force without requiring direct motor-to-frame coupling
Solution Approach 2:
The patent replaces part of the purely mechanical operation with an electromechanical system. The electric motor drive substitutes for manual effort in overcoming the retraction force, while the threaded spindle provides mechanical motion conversion, creating a hybrid system that reduces user effort while maintaining mechanical reliability
2Productivity
If a threaded spindle mechanism is used for automatic retraction, then productivity is improved, but device complexity increases
Solution Approach 1:
The threaded spindle is extended in advance by the electric motor drive to push the pull-out frame over the retraction device's area of influence before the user needs to manually pull it out. This preliminary action prepares the system by overcoming the retraction force ahead of time, making subsequent manual operation easier and faster
Solution Approach 2:
The system provides self-service through automatic retraction. When the pull-out frame reaches its fully extended position, the threaded spindle automatically retracts, pulling the frame back without user intervention. This self-service feature improves productivity by eliminating manual retraction effort while the delay circuit prevents unintended activation
3Ease of operation
If the electric motor drive extends the threaded spindle to overcome retraction force, then ease of operation is improved, but reliability decreases
Solution Approach 1:
The system dynamically adapts its operation mode. During extension, the electric motor drive actively assists by extending the threaded spindle to overcome retraction force. During retraction, the system transitions to passive mode where the user manually pulls the frame, and the motor remains inactive. This dynamic switching maintains ease of operation while avoiding reliability issues from continuous motor operation
Solution Approach 2:
The electric motor drive operates periodically rather than continuously. It activates only during specific phases (when extension assistance is needed or when automatic retraction should occur) and remains inactive during manual operation phases. This periodic action reduces wear and potential failures while maintaining operational ease when activated
4Reliability
If a delay circuit is incorporated to prevent accidental operation, then reliability is improved, but device complexity increases
Solution Approach 1:
The delay circuit provides beforehand cushioning against accidental operation. When the pull-out frame reaches its fully extended position, the delay circuit prevents immediate automatic retraction, allowing a time buffer for the user to react or correct potential errors. This cushioning effect protects against unintended system actions while maintaining overall reliability
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
Enables effortless extension and retraction of the pull-out frame, maintaining functionality even when heavily loaded, and prevents accidental operation by incorporating a delay mechanism, ensuring safe and reliable use.
Implementation Method 1
an electric motor drive for pushing the other part in relation to one part of the guide rail over the area of influence of the retraction device, with the electric motor drive extending a non-rotatably mounted threaded spindle by turning a spindle nut arranged on a threaded spindle and itself stationarily mounted
Implementation Method 2
The retraction device can use a spring to generate the force with which it acts on the other part of the guide rail and thus the pull-out frame over a limited area of influence into a position that is pushed in
Implementation Method 3
The force can also be traced back to an inclined plane on which rollers roll, over which the parts of the guide rail are guided to one another. In the case of a retraction device with an inclined plane, the force applied by the retraction device increases with the weight of the pull-out frame or all parts attached or attached thereto
Implementation Method 4
a damper can be arranged between the two parts of the guide rail for the pull-out frame, which gently brakes the movement of the pull-out frame into its pushed-in position and does not allow it to hit hard against a stop
Data Source
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AI summary
The fitting has a guide rail (10) with two parts (12, 13), of which one is fastened to a cupboard base/top and other supports an extending frame. An electromotor actuator (21) that is provided for the part (13) is driven during the activation of a threaded spindle (22) by turning of a fixedly supported spindle nut (23), in order to push the part (13) against the part (12). The actuator pushes the part (13) against the part (12) over an impact region of a drawing device (16) and not to a maximum drawing position, and again drives the spindle independent of further movements of the part (13).