Patent · US Expired

Apparatus for the determination of the distance traveled by a piston in a cylinder

US4638670A · kind A · utility

37Cited by
7References
20Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 16, 1985
Grant dateJan 27, 1987
Priority date
Expiry dateAug 16, 2005

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01D5/18
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Apparatus for the determination of the location and/or distance traveled by a piston in a cylinder. This apparatus can easily be integrated into shock absorbers, vibration dampers and pneumatic springs, and exhibits a high degree of insensitivity to at least electrical interference, therefore being particularly well-suited for operation under unfavorable ambient conditions. As a result of the use of the most modern semiconductor technology and a suitable geometric arrangement, a very good resolution can be achieved, along with an automatic recognition of the direction of piston travel. Such an apparatus has a number of semiconductor elements; in one embodiment, in a beam fastened inside the cylinder or, in another embodiment, in the hollow piston rod. These semiconductor elements are arranged so that, over the axial length of the piston stroke, the distances between two neighboring semiconductor elements correspond to a specified measurement value resolution. The semiconductor elements are connected with an electronic calculating or computing system, and the component opposite the semiconductor elements is an electrode which generates an electric field. This electrode is connected …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.