High speed capacitance apparatus for classifying pharmaceutical capsules
US4223751A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1979 |
| Grant date | Sep 23, 1980 |
| Priority date | — |
| Expiry date | Mar 26, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01G17/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A dielectric tube, such as glass or plastic, having a square cross section extends between the two plates of a capacitance-sensing transducer. The opposite sides of the tube have a spacing only slightly greater than the diameter of the capsules to be checked. The capsules to be classified are oriented prior to their introduction into the tube so that they enter in an end-to-end relationship. The requisite spacing between the capsules is accomplished by an air jet device that rapidly accelerates the leading capsule as it enters the tube to such a velocity that it leaves the transducer before the next capsule enters, thereby assuring that only one capsule is in the transducer at any given moment. The capacitance-sensing transducer is repeatedly charged and discharged by means of a high frequency oscillator circuit. Capacitance variations from capsule to capsule are measured on a continuous analog basis and logic signals derived from such analog signals are used to determine whether a given capsule should be accepted or rejected. A reject mechanism diverts each bad capsule from the stream of acceptable or good capsules.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.