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:
Jun. 25, 1996
Filed:
Apr. 11, 1995
Hoffmann-La Roche Inc., Nutley, NJ (US);
Abstract
An analyzer has a horizontally disposed baseplate on which primary containers and secondary containers are disposed; a pipetting needle of an electrically conductive material connected to a metering device by a tubing, for transferring a predetermined volume of liquid each time from a primary container to a secondary container; a transport device for the controlled transport of the pipetting needle in three directions at right angles to one another, two of the transport directions extending horizontally and the third transport direction extending vertically; an electrically conductive reference body rigidly connected to baseplate and which in each of the horizontal transport directions has two outer surfaces disposed perpendicularly to the transport direction; and a control device for controlling the metering device and the transport is device. For fine adjustment of the pipetting needle transport device, there is provided a circuit for measuring the electrical capacitance between the pipetting needle and the reference body, and a device for determining the coordinates of a reference position of the pipetting needle in at least one of the horizontal transport directions. The device is adapted to move the transport device of the pipetting needle so that the pipetting needle is moved in opposite directions in each case to a position near each of the two outer surfaces of the reference body. The pipetting needle is moved in each case towards a surface of the reference body until the value of electrical capacitance between the pipetting needle and the reference body, as measured by the circuit, reaches a predetermined value corresponding to a specific distance between the pipetting needle and the surface of the reference body.