Sailing course computer
US4446729A · kind A · utility
Inventor
Key dates
| Filing date | Oct 23, 1981 |
| Grant date | May 8, 1984 |
| Priority date | — |
| Expiry date | Oct 23, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C21/203
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sailing course computer instantaneously and continuously computes a sailboat's speed towards a predetermined destination. In a first embodiment, a polarizer disk is utilized as a compass card through which a light source may be directed. An analyzer disk is positioned below the polarizer disk, and a photocell below the analyzer disk then provides a signal indicative of the amount of light passing through the two disks in response to the sailboat assuming various headings. A second signal input is provided by a knotmeter, and appropriate electronic circuitry is then used to indicate the speed of the sailboat towards a given destination. In a second embodiment, a light source is provided on one side of a compass card and a photocell is provided on the other, with a circular aperture being positioned tangentially to the center of the card so as to permit light impingement from the light source upon the photocell. The photocell then provides an electric signal indicative of the amount of light passing through the aperture to a computing circuit for determining the speed relative to the destination. In both embodiments of the invention, the electronic circuitry is utilized to compute …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.