Position determining apparatus
AssigneeWhessoe Limited
InventorRobert J. Redding
Life of this patent
Estimating the term…
Abstract
A position determining apparatus comprising a taut electrically-conductive member; a pulse generator to feed a pulse of electric current along the member; a magnet located at a variable first point along the member, for example on a float on the surface of a liquid the level of which is to be determined, to apply a magnetic field to the member at that point; and a transducer positioned at a second point along the member to sense the arrival at the second point of a mechanical impulse induced in the member by interaction between the current pulse and the magnetic field as the current pulse passes the magnet. A time measuring circuit responsive to the time interval between the feeding of the current pulse and the arrival of the mechanical impulse at the second point is used to determine the position of the first point.
Claims11
Position determining apparatus, comprising a taut elongate electrically-conductive member;
- first and second connection means electrically-connected to said member at respective connection positions spaced apart along said member;
- a first magnet variably positioned to apply a first magnetic field to said member at a first point located anywhere between said connection positions, the position of which said first point along said member is to be determined;
- a pulse generator connected to said first connection means and operable to feed a pulse of electric current along said member from said first connection means to the other, which current pulse interacts with said first magnetic field as said current pulse travels past said first point thereby causing a mechanical impulse to propagate along said member;
- means positioned at a second point along said member to sense the arrival of said mechanical impulse at said second point;
- and transducer means located along said member to be responsive to said arrival of said mechanical impulse at said second point to determine said position of said first point.
A liquid level indicating system, comprising:
- a container at least partially filled with liquid the level of the surface of which is to be measured;
- a taut elongate electrically-conductive member mounted substantially vertically and partly immersed beneath said liquid surface;
- first and second connection means electrically-connected to said member at connection positions respectively above and below said surface;
- float means arranged to float on said surface and to be guided by said member;
- a first magnet carried by said float means and adapted to apply a magnetic field to said member at a first point related to said liquid surface;
- a pulse generator connected to said first connection means and operable to feed a pulse of electric current along said member from said first connection means to the other, which current pulse interacts with said magnetic field as said current pulse travels past said first point thereby causing a mechanical impulse to propagate along said member;
- transducer means located along said member at a second point along said member to sense the arrival of said mechanical impulse at said second point;
- and time dependent means responsive to said arrival of said mechanical impulse at said second point to determine the position of said liquid surface.
Dependencies are inferred from the claim text.