US 6,341,523 · Granted 2002-01-29

The Rain Sensor Bracket That Lets Your Windshield Wiper Think for Itself

This patent describes a clever mounting bracket that sticks to your windshield and holds a moisture-detecting sensor in just the right spot. The sensor uses a spring to stay pressed against the glass so it can sense when raindrops hit, which then tells your wipers to turn on automatically without you having to touch anything.

The plain-English version

What it protects

The claim covers a mounting system for a rain sensor that attaches to the inside of a windshield using adhesive. What's protected here is the specific arrangement: a housing with an opening on one side where the sensor sits, a spring or disc that pushes the sensor forward, and a port on the opposite side that lets the sensor detect moisture on the outer windshield surface. The design also includes a mirror-mounting button integrated into the housing itself, making it a dual-function bracket.

Why it matters

Rain-sensing wipers became a competitive selling point for mid-range and luxury vehicles in the 1990s and 2000s—Donnelly Corporation was a major supplier to automakers. This patent protects the specific engineering that makes the sensor reliable: how it's mounted, how the spring keeps it in contact with the glass, and how the port is positioned for accurate moisture detection. A well-designed mount means fewer false triggers and longer sensor life, directly affecting customer satisfaction.

Real-world use

When you're driving in light rain and your wipers suddenly start moving on their own without you touching the stalk, you're experiencing a rain sensor mounted exactly like this one—stuck to the inside of your windshield, constantly checking for moisture.

Original USPTO abstract

A mount for mounting a rain sensor includes a housing having an access opening on first side and a port on second side for positioning adjacent an inner surface of the vehicle windshield. The second side is adapted for mounting to a vehicle windshield, for example by a layer of adhesive which is interposed between the housing and the windshield. Optionally, the housing includes an access opening and a cover, which and covers the access opening. A mirror mounting button is provided on either the housing or the cover for mounting a rearview mirror assembly to the mount. A biasing member is supported in the housing and is interposed between the first side of the housing and a rain sensor positioned in the housing, which urges a detecting surface of the rain sensor to project through the port and to optically couple the rain sensor to the vehicle windshield for detecting moisture on an outer surface of the vehicle windshield. The biasing member may comprise, for example, a helical spring or a urethane disc.

Patent details

Publication number
US 6,341,523
Filing date
2001-05-18
Grant date
2002-01-29
Assignee
Donnelly Corporation
Inventor(s)
LYNAM NIALL R.
CPC class
B60S1/0822

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