Door Operator Clutch Disengagement for Manual Force Reduction
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Solution Overview
Problem
Conventional automatic door operators face issues such as high manual opening force requirements due to spring resistance, wear on gear trains, limited clutch mechanism range of motion, and security concerns from delayed door closure, especially in weather-sensitive or high-security environments.
Innovation Solution
A door operator system featuring a motor, operator arm assembly, clutch assembly, and door position sensor, where the clutch disengages during manual operation and re-engages automatically, allowing for controlled door positioning and immediate closure after passage, reducing manual effort and enhancing security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a spring mechanism is used in the door closer to return the door to closed position, then the door can be closed without additional electrical energy, but the spring force is large requiring substantial manual force to open the door and causing quick wear on the gear train
Solution Approach 1:
The patent removes the spring mechanism from the door operator system. Instead of using a spring to return the door to closed position, the system uses a motor controlled by a controller that receives signals from presence sensors. This extraction of the spring mechanism eliminates the large spring force that required substantial manual effort to overcome during door opening.
Solution Approach 2:
The patent replaces the mechanical spring-based door closer with an electrically-controlled motor system. The motor is controlled by a controller that receives signals from presence sensors (ultrasonic, photoelectric, or motion sensors) to automatically close the door when appropriate, eliminating the need for mechanical spring force and reducing wear on gear trains.
2Reliability
If a clutch mechanism is used to enable free manual door movement, then safety is improved when objects are in the door's pathway, but the clutch creates drag or resistance when the door is manually opened or closed
Solution Approach 1:
The patent replaces the mechanical clutch mechanism with an electrically-controlled motor system. The motor is engaged or disengaged through electrical control based on sensor signals, eliminating the mechanical drag and resistance created by clutch mechanisms while maintaining safety through automatic reversal functionality.
Solution Approach 2:
The patent introduces a controller as an intermediary between the presence sensors and the motor. The controller processes sensor signals and controls motor operation to enable safe manual door movement without the drag created by mechanical clutches. The controller acts as a mediator that coordinates sensor input with motor response.
3Duration of action of moving object
If a predetermined time delay is used between opening and closing sequences, then the door remains open for extended periods allowing passage, but security is compromised and heat loss or heat gain increases
Solution Approach 1:
The patent uses presence sensors (ultrasonic, photoelectric, or motion sensors) that provide continuous feedback about whether objects or persons are present in the doorway area. The controller monitors this feedback in real-time and adjusts door closing timing accordingly, closing the door immediately when the passage area is clear rather than using a fixed time delay. This feedback mechanism maintains security and energy efficiency while allowing adequate passage time.
Solution Approach 2:
The patent makes the door closing timing dynamic rather than fixed. The door remains open as long as presence sensors detect objects or persons in the passage area, and closes immediately when the area is clear. This dynamic adjustment optimizes both passage convenience and security/energy efficiency based on real-time conditions.
4Ease of operation
If the motor continues to open the door after the user has moved through, then the door reaches fully open position ensuring complete passage, but security risk increases and heat loss or heat gain occurs
Solution Approach 1:
The patent uses presence sensors to provide continuous feedback about user passage through the doorway. The controller monitors this feedback and stops the door opening sequence immediately when it detects that the user has moved through the doorway, rather than allowing the door to reach the fully open position. This feedback-based control maintains security while ensuring complete passage.
Solution Approach 2:
The patent applies partial action by opening the door only to the extent necessary for user passage rather than always opening it fully. The motor opens the door sufficiently to allow the user to pass through, then stops when presence sensors indicate the user has moved through, avoiding the excessive action of opening the door completely when not necessary for security and energy efficiency.
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 system reduces manual opening force, minimizes gear train wear, and enhances security by ensuring immediate door closure after passage, addressing the limitations of conventional systems.
Implementation Method 1
The clutch assembly includes a friction disc and a spring. The spring biases the friction disc against a surface of the operator arm to prevent relative movement between the friction disc and the operator arm when the door operator is in automatic mode.
Implementation Method 2
The clutch assembly includes a friction disc and a spring. The spring biases the friction disc against a surface of the operator arm to prevent relative movement between the friction disc and the operator arm when the door operator is in automatic mode.
Data Source
AI summary
A door operator for selectively opening and closing a side hinge door. The door operator may include a motor with a drive shaft, an operator arm assembly, a door position sensor, and a controller. The operator arm assembly may include an output shaft operatively coupled to the drive shaft, an operator arm, and a clutch assembly mounted to the output shaft. The door position sensor, which may be electro-magnetic, signals the controller when the door is not closed. If the door has been manually pushed open, the controller signals the motor to rotate the drive shaft in the closing direction. In automatic mode, the output shaft and the operator arm are operatively engaged, but manual force to open the door overcomes static friction between the operator arm and friction discs in the clutch assembly, operatively disengaging the operator arm and output shaft until the manual force is removed.