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:
Jan. 08, 1985
Filed:
Sep. 17, 1981
Dieter Koch, Ettlingen, DE;
Tonio Gianotti, Weinheim, DE;
Bruker-Analytische Messtechnik GmbH, Rheinstetten-Forchheim, DE;
Abstract
A multiple piston pump with a constant discharge capacity for liquid chromatographs comprises at least three piston-cylinder units (1,2,3), whereof the pistons (7) are driven through a non-linear drive by a motor (23) with a mutual phase displacement of 360.degree./n, when n represents the number of piston-cylinder units. A regulating system varies the speed of the motor (23) during each period or cycle of the piston movement in such a manner as to compensate for the non-linear drive so that the pressure of the liquid conveyed during each period or cycle remains at least approximately constant. The motor (23) can be constructed as a stepping motor, which is supplied with current pulses whereof the frequency determines the speed of the motor.