The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 27, 1987
Filed:
Nov. 30, 1984
Edmund Schiessle, Schorndorf, DE;
Werner Forkel, Stuttgart, DE;
Abstract
A device is provided for the indirect contactless electrical measuring of short distances, particularly for measuring the stroke and/or the position of nozzle needles for injection nozzles of internal combustion engines. A coil having a solid core of a soft-magnetic alloy is used as magnetic field sensor and a low-mass permanent magnet. The permanent magnet is rigidly connected to a moving control element. The nozzle needle is fixed to the control element. Movement of the permanent magnet in relation to the coil causes a change in the magnetic flux density in the core of the coil and, via the nonlinear function B=f(H) of the mangetization curve, effects a change in the dynamic permeability and consequently in the inductance of the coil. The change in inductance of the coil is converted by a suitable electronic evaluating circuit into a path-analogue signal to determine the distance between the fixed coil and the movable permanent magnet. Thus, movement of the nozzle needle which is fixed in relation to the permanent magnet can be precisely monitored.