Sample liquid transfer means in an automatic chemical testing apparatus
US4140488A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1977 |
| Grant date | Feb 20, 1979 |
| Priority date | — |
| Expiry date | Sep 6, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01L3/022
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Means for reducing intersample contamination in an automatic chemical testing apparatus, in which liquid from a sample is aspirated from a sample source into a reservoir, and aliquots of the sample are each dispensed into individual reaction containers for analysis by well-known means. A cylindrical reservoir is utilized with a piston therein shaped for pushing out virtually all of the remaining sample from the cylinder after dispensing the sample liquid through a hollow needle, communicating with the cylinder. A solid pin coaxially mounted within the piston is projected through the needle and has minimum clearance therewith, for pushing remaining sample out of the needle. The portion of the pin projecting through the needle is retracted into the piston prior to aspiration of liquid from a next sample.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.