Electrical Switch Sealing Assembly for Ingress Protection
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Solution Overview
Problem
Existing electrical switches in hand-held devices face challenges in preventing ingress of particulates, dust, and water, leading to potential short circuits, electric shock, and non-operability, while also being bulky and prone to accidental activation, which affects longevity and safety.
Innovation Solution
A sealing assembly with an elastically resilient polymeric sealing element and a rail assembly that maintains sealing engagement as the actuator moves, preventing ingress through the aperture and ensuring the switch remains operational and safe.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an encapsulating membrane is used to cover the switch, then protection against particulates and water is improved, but the device becomes bulky and the membrane may tear through repetitive use
Solution Approach 1:
The patent employs a thin film membrane made of flexible material that conforms to the switch actuator surface. This membrane provides protective sealing against particulates and water while maintaining a compact form factor. The flexibility of the thin film allows it to deform with actuator movement without tearing, resolving the contradiction between protection and durability.
Solution Approach 2:
The membrane is nested within the switch housing structure, with the actuator extending through the membrane in a telescoping arrangement. This nesting approach provides protection without adding external bulk, as the protective element is integrated within the existing device geometry rather than adding external volume.
2Ease of operation
If the switch is made compact for hand-held devices, then ease of operation is improved, but prevention of ingress of foreign matter and water becomes more difficult
Solution Approach 1:
The flexible membrane provides an effective seal in the compact switch design, preventing ingress of foreign matter and water while maintaining small dimensions suitable for hand-held devices. The membrane's ability to conform and seal effectively in a compact geometry resolves the contradiction between compactness and protection.
3Ease of operation
If the actuator is exposed through an aperture for easy access, then ease of operation is improved, but ingress of water and particulates increases
Solution Approach 1:
The membrane is positioned within the aperture opening, allowing the actuator to extend through the membrane for easy access while the membrane itself blocks ingress of water and particulates. This resolves the contradiction by maintaining accessibility while providing protection at the exposure point.
Solution Approach 2:
The membrane acts as an intermediary element between the external environment and the switch actuator. It allows mechanical interaction with the actuator while mediating against harmful factors, permitting operation while blocking ingress of water and particulates.
4Reliability
If a rigid sealing structure is used to prevent ingress, then protection is improved, but the switch becomes bulky and complex
Solution Approach 1:
The flexible membrane provides effective sealing against ingress without requiring complex rigid structures. The simplicity of the thin film solution reduces device complexity while maintaining reliable protection, resolving the contradiction between protection and structural simplicity.
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 solution effectively prevents particulates, dust, and water ingress, enhancing the longevity and safety of hand-held devices by maintaining sealing engagement during actuator movement without impeding the switch's operation, while also addressing bulkiness and accidental activation concerns.
Implementation Method 1
the sealing element is formed from an elastically resilient polymeric material such that when retained by the engagement element, sealing engagement between the first complementary abutment portion of the sealing element and the first abutment portion is effected as the first complementary abutment portion is urged against the first abutment surface of the engagement element
Data Source
Figure 1a
Figure 1b
Figure 1c~1d
AI summary
A sealing assembly for prevention of ingress of particulates and water into an electrical switch having two or more positions moveable between a first extremity and a second extremity in a linear direction of movement by an actuator, whereby said actuator is operable through an aperture extending through the outer surface of a housing of the electrical switch, said sealing assembly comprising an engagement element including a rigid first abutment portion for circumscribing the aperture extending through the outer surface of the housing of the switch and a rigid first retention portion; and a sealing element being slidingly engageable with the engagement element in a direction of said linear direction of movement of the actuator and being retained by the retention portion of the engagement element, said sealing element including a first complementary abutment portion for sliding engagement with the first abutment portion of the engagement element; wherein the sealing element is formed from an elastically resilient polymeric material such that when retained by the engagement element, sealing engagement between the first complementary abutment portion of the sealing element and the first abutment portion is effected as the first complementary abutment portion is urged against the first abutment surface of the engagement element so as to occlude passage and ingress of particulates, dust and water from external of the first abutment portion to the aperture extending through the outer surface of a housing of the electrical switch; and wherein upon movement of the sealing element in conjunction with movement of the actuator of the electrical switch between the first extremity and the second extremity, said sealing engagement between the first complementary abutment portion of the sealing element and the first abutment surface of the engagement element is maintained.