Magnetic compass card
OwnerPaul Chapmaninventor
Life of this patent
Estimating the term…
Abstract
The balancing righting moments and dampening of the compass card and directive magnets in a liquid damped magnetic compass are separated to reduce the tilt and oscillation of the compass card when subjected to lateral acceleration, such as pitching and rolling in a seaway. The compass card is connected to the pivoted directive magnetic assembly by a card gimbal arrangement. The compass card is connected to the outer side of the gimbal ring rotating on a first axis. The magnetic assembly is connected to the inner side of the gimbal ring for rotation along a second axis oriented 90 degrees from the first axis.
Claims11
A magnetic compass comprising:
- a liquid filled spherical compass bowl,
- a compass card and magnetic assembly characterized by two sets of two axis gimbals, a first set coupling the bowl to a central vertical pivot on which the directive magnet assembly rests and can freely rotate and a second gimbal set coupling the directive magnet assembly to the compass card.
A magnetic compass comprising:
- a liquid filled spherical compass bowl,
- a compass card and magnetic assembly characterized by two sets of two axis gimbals, a first set coupling the bowl to a central vertical pivot on which the directive magnet assembly rests and can freely rotate and a second gimbal set coupling the directive magnet assembly to the compass card;
- wherein the magnet assembly comprises two parallel cylindrical rare-earth magnets straddling the pivot axis and having a centre of mass below a pivot point of the central pivot.
A magnetic compass comprising:
- a liquid filled spherical compass bowl,
- a compass card and magnetic assembly characterized by two sets of two axis gimbals, a first set coupling the bowl to a central vertical pivot on which the directive magnet assembly rests and can freely rotate and a second gimbal set coupling the directive magnet assembly to the compass card;
- wherein the magnet assembly comprises two parallel cylindrical rare-earth magnets straddling the pivot axis and having a centre of mass below a pivot point of the central pivot.
A magnetic compass comprising:
- a liquid filled spherical compass bowl, and
- a compass card and magnetic assembly characterized by two sets of two axis gimbals, a first set coupling the bowl to a central vertical pivot on which the directive magnet assembly rests and can freely rotate and a second gimbal set coupling the directive magnet assembly to the compass card;
- wherein the magnet assembly comprises two parallel cylindrical rare-earth magnets straddling the pivot axis and having a centre of mass below a pivot point of the central pivot.
A magnetic compass comprising:
- a liquid filled spherical compass bowl, and
- a compass card and magnetic assembly characterized by two sets of two axis gimbals, a first set coupling the bowl to a central vertical pivot on which the directive magnet assembly rests and can freely rotate and a second gimbal set coupling the directive magnet assembly to the compass card;
- wherein the two-axis card gimbal comprises a gimbal ring with inner swivel pins coupled to a housing of the magnet assembly and outer swivel pins coupling the gimbal ring to the compass card;
- the two-axis card gimbal comprises a gimbal ring with inner swivel pins coupled to a housing of the magnet assembly and outer swivel pins coupling the gimbal ring to the compass card, and
- the magnet assembly comprises two parallel cylindrical rare-earth magnets straddling the pivot axis and having a centre of mass below a pivot point of the central pivot.
Dependencies are inferred from the claim text.