FR2761770A1

FR2761770A1 - Device for measuring the deviation of fixed ships compasses.

Info

Publication number: FR2761770A1
Application number: FR9704255A
Authority: FR
Inventors: Philippe Ador
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-04-08
Filing date: 1997-04-08
Publication date: 1998-10-09

Abstract

The device use the sun as a reference. It includes a plate(1) having a hole(4) in which is fixed a shadow stick(2) that throws a shadow(3) as a function of the suns position. An arrowhead mark on the plate is pointed in the travel direction of the ship, at solar midday the fixed ships compass deviation can be found by comparing the shadow angle indicated on the devices plate to the heading indicated by the ships compass, which is influenced by the magnetic masses onboard the ship. Angles are marked on the device, from right to left, every 15 degrees and indicate the four main headings and their intermediates, North, North-east, East, South-east, South, South-west, West, North-west. The plate(1) also has arrowhead marks(6), one of which points North in the North hemisphere and the other point South in the South hemisphere.

Description

La présente invention concerne un dispositif pour mesurer la déviation des compas fixe sur un navire en prenant le soleil comme référence. The present invention relates to a device for measuring the deviation of the fixed compass on a ship taking the sun as a reference.

Le compas fixe du navire donne le cap du bateau part rapport au nord magnétique, mais celui-ci subit les influences des masses magnétiques qui sont à bord du navire. The fixed compass of the ship gives the course of the boat relative to the magnetic north, but this one undergoes the influences of the magnetic masses which are on board the ship.

Le dispositif selon l'invention permet de mesurer la déviation que le compas subit et de remédier à cette inconvéniant. The device according to the invention makes it possible to measure the deviation that the compass undergoes and to remedy this drawback.

Il comporte un plateau sur lequel est tracé un rapporteur gradué tous les 15 degrés et indiquant les quatre caps géographiques et leurs intermédiaires, Nord, Nord-Est,
Est, Sud-Est, Sud, Sud-Ouest, Ouest, Nord-Ouest.It includes a tray on which is drawn a protractor graduated every 15 degrees and indicating the four geographical headings and their intermediaries, North, North-East,
East, South-East, South, South-West, West, North-West.

Ce plateau est pourvu d'un gnomon qui trace une ombre sur le plateau grâce au soleil. This tray is provided with a gnomon which traces a shadow on the tray thanks to the sun.

En utilisant ce dispositif au midi solaire du lieu où l'on se trouve, on peut connaître la déviation du compas fixe en comparant l'angle indiqué par l'ombre que forme le gnomon sur le plateau et le cap qu'indique le compas magnétique fixe. By using this device at the solar noon of the place where we are, we can know the deviation of the fixed compass by comparing the angle indicated by the shadow that forms the gnomon on the plate and the heading indicated by the magnetic compass fixed.

Les dessins annexés illustrent l'invention:
La figure 1 représente en perspective le dispositif de l'invention.The accompanying drawings illustrate the invention:
Figure 1 shows in perspective the device of the invention.

La figure 2 représente le tracé du rapporteur gradué pour l'hémisphère Nord. Figure 2 shows the plot of the graduated protractor for the northern hemisphere.

La figure 3 représente le tracé du rapporteur gradué pour l'hémisphère Sud. Figure 3 shows the plot of the graduated protractor for the southern hemisphere.

En référence à ces dessins, le dispositif comporte un plateau (1), qui est muni d'un orifice (4) ayant pour fonction de recevoir le Gnomon (2) qui, grâce au soleil forme l'ombre (3) sur le plateau (1). With reference to these drawings, the device comprises a plate (1), which is provided with an orifice (4) having the function of receiving the Gnomon (2) which, thanks to the sun forms the shadow (3) on the plate (1).

Sur le plateau (1) se trouve imprimé un rapporteur (5), une flèche (6) et l'indication de l'hémisphère (7). On the plate (1) is printed a protractor (5), an arrow (6) and the indication of the hemisphere (7).

Après avoir installé le gnomon (2) dans l'orifice (4) du plateau (1) choisi en fonction de l'hémisphère (7) où l'on se trouve, on place le taximètre sur le pont du bateau, la flèche (6) représentant l'avant du bateau. After installing the gnomon (2) in the orifice (4) of the tray (1) chosen according to the hemisphere (7) where we are, we place the taximeter on the deck of the boat, the arrow ( 6) representing the bow of the boat.

On met le bateau cap au Nord. L'ombre (3) que crée le gnomon (2) sur le plateau (1) doit se trouver sur le O -Nord du tracé (5), sinon prendre un cap qui permet d'obtenir l'ombre du gnomon sur le O -Nord-. We set sail for the North. The shadow (3) that the gnomon (2) creates on the board (1) must be on the O-North of the course (5), otherwise take a course which allows to obtain the shadow of the gnomon on the O -North-.

Relevé le cap indiqué par le compas magnétique. Read the heading indicated by the magnetic compass.

Faire un grand cercle de 3600 avec le navire et relevez tous les 450 indiqué par le taximètre les indications du compas magnétiques. Make a large circle of 3600 with the ship and take all the 450 indicated by the taximeter the indications of the magnetic compass.

Une fois les relevés effectués, soustraire de la valeur relevé sur le compas magnétique la valeur de la déclinaison mentionné sur les cartes marines et l'on obtient ainsi la déviation du compas à vérifier et les valeurs pour le régler. Once the readings have been taken, subtract from the value recorded on the magnetic compass the value of the declination mentioned on the nautical charts and one thus obtains the deviation of the compass to be checked and the values to adjust it.

Le dispositif selon l'invention est particulièrement destiné au réglage des compas magnétiques fixes de la marine de plaisance et plus généralement tous les compas magnétiques fixes. The device according to the invention is particularly intended for adjusting the fixed magnetic compasses of the pleasure craft and more generally all the fixed magnetic compasses.

Ses dimensions, à titre d'exemple non limitatif, sont, pour le plateau de 20 cm au carré et pour le gnomon de 15 cm de long pour un diamètre de 0,6 cm. Its dimensions, by way of nonlimiting example, are, for the plate of 20 cm squared and for the gnomon of 15 cm long for a diameter of 0.6 cm.

Claims

1) Device for measuring the deviation of the fixed compass on a ship taking the sun as a reference, characterized in that it comprises a plate (1) having an orifice (4) in which the gnomon (2) is fixed, which forms a shadow (3) depending on its orientation once placed on the deck of the boat, the arrow in the direction of navigation of the ship, which allows using this device at midday solar from where we are, to know the deviation of the fixed compass by comparing the angle indicated by the shadow that the gnomon forms on the plate and the heading indicated by the fixed magnetic compass which is influenced by the magnetic masses which are on the boat.

2) Arrangement according to claim 1 characterized in that the marking of the angles on the apparatus is traced on a protractor graduated in the direction from right to left every 15 degrees and indicating the four geographical headings and their intermediaries, North, North-East, East, South-East, South,

South West, West, North West and is done on both sides.

3) Arrangement according to claim 2 wherein one of the markings (5) is valid with an arrow (6) towards the North for the Northern hemisphere and the other with an arrow (6) towards the

South for the Southern Hemisphere.