Switch Unit Proximity Sensor Dynamic Electrical Contact

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Solution Overview

Problem

Existing switch units with proximity sensors face challenges in manufacturing cost reduction while ensuring reliable electrical contacting, particularly in designs where permanent contact is not necessary across all movement states of the actuating element.

Innovation Solution

The electrical contacting of the proximity sensor is interrupted when the actuating element is in an actuated state and closed when in a non-actuated state, utilizing a restoring force from a switch or elastic element to maintain contact only when necessary, allowing for reliable connection between movable and stationary components without permanent electrical bridging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If permanent electrical contact is provided for the proximity sensor in all movement states, then reliable electrical connection is ensured, but manufacturing cost increases and device complexity increases

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The electrical contact state is made dynamic rather than static. The contact between contact areas 34 and 36 changes based on the actuating element's position: closed when the element is in its initial position (enabling proximity sensor function), and open when the element is actuated (disabling proximity sensor function). This dynamic contact state allows the system to adapt to operational requirements, reducing manufacturing complexity while maintaining reliability when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electrical contact is periodically closed and open based on the operational cycle. During normal operation, the contact is closed to enable proximity sensing. When the actuating element is deliberately moved to actuated state, the contact opens to interrupt the circuit. This periodic on/off contact pattern matches the functional requirements of different operational phases.

Inventive Principle:
Principle #19Periodic action

2Reliability

If permanent electrical contact is provided for the proximity sensor, then reliable electrical connection is ensured, but device complexity increases due to need for flexible cables or sliding contacts

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The complex flexible cable or sliding contact mechanisms are extracted and removed from the design. Instead of providing continuous electrical connection through complex movable structures, the patent uses simple contact areas 34 and 36 that naturally make or break contact based on the actuating element's position. This extraction eliminates unnecessary complexity while maintaining the essential electrical connection function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The electrical contact system serves itself through the natural movement of the actuating element. The contact areas 34 and 36 automatically make contact when the actuating element is in its initial position and automatically separate when actuated, without requiring additional actuators, flexible cables, or sliding mechanisms. The system uses its own operational movement to control the electrical connection state.

Inventive Principle:
Principle #25Self-service

3Ease of manufacture

If electrical contact is interrupted when actuating element is actuated, then manufacturing cost is reduced, but reliability may be compromised during transition states

Engineering Contradiction:
Improvemanufacturing costVSAvoidelectrical connection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The contact areas 34 and 36 are positioned and dimensioned to ensure reliable contact establishment before the actuating element reaches its actuated position. The contact geometry and material properties are designed to maintain stable electrical connection during the transition phase, preventing intermittent or unreliable contact states. This preliminary design ensures that the contact is firmly established before any state change occurs.

Inventive Principle:
Principle #10Preliminary action

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

This approach reduces manufacturing and assembly costs by eliminating the need for permanent contact in all movement states, ensuring reliable electrical connection only when required, thereby enhancing the switch unit's functionality and cost-effectiveness.

Implementation Method 1

Capacitive proximity sensors can have capacitors whose capacitance changes when the sensor is approached or touched

Methodology Applied
Scientific EffectCapacitive principle: Capacitance

Implementation Method 2

In the case of inductive proximity sensors, an oscillator generates a high-frequency electromagnetic alternating field. If an object enters this alternating field, the oscillator voltage is dampened

Methodology Applied
Scientific EffectInductive principle: Electromagnetic Induction

Implementation Method 3

the actuating element can be elastically deformed by actuation and generates a restoring force which closes the electrical contact and/or keeps it in a closed state

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 4

the switch unit comprises a separate elastic element, in particular designed as a spring

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP1758137B1Switch unit with a proximity sensor
Publication Date: 2009.12.09 VALEO SCHALTER & SENSOREN GMBH
  • EP1758137B1 patent drawingFigure 1~3

AI summary

The switch unit (100) has a motion-operating actuator (10) which is electrically in contact with a proximity sensor (18). The electrical contact between the proximity sensor and actuator is opened when the actuator is in operated condition, and closed when the actuator is in unactuated condition. A switch (16) is included for stroking, pushing or tilting the actuator to operate the actuator. The switch is also used for resetting the actuator and for closing and holding the electrical contact between the actuator and proximity sensor.