Apparatus and method for dispensing small quantities of particles
US7358451B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 2005 |
| Grant date | Apr 15, 2008 |
| Priority date | — |
| Expiry date | Aug 3, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01G13/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
There is disclosed an apparatus and method which is capable of dispensing very small (typically less than 5 mg) quantities of particles to a high accuracy in a repeatable way and without undue wastage. Also, the need for advanced particle formulation is reduced. The apparatus comprises a closed loop control system which uses an electromechanical actuator to deliver impact energy to a supply of particles initially held on a sieve in a hopper. The impact energy causes a small number of particles to fall through the sieve and onto a weight measuring balance. The weight obtained is scrutinised by a processor to see if further actuations are required. In preferred embodiments, the energy of actuation is varied in accordance with the rate of dispensation calculated by the processor. Also, a correction amount can be obtained to take account of the fact that the balance can take a considerable amount of time to settle to its final value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.