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. 18, 1991
Filed:
Dec. 26, 1989
Christoph Maurer, Ringstrasse, DE;
Dragerwerk Aktiengesellschaft, Lubeck, DE;
Abstract
The present invention pertains to a pump, in which two pistons moving in the same direction in a common cylinder bore are provided to generate the suction intake and pressure, discharge effects as well as for control. Both pistons are held by fastening members to perform a lifting movement, and one of the pistons is a control piston for performing a constant lifting movement, while the other piston is a pump piston for performing a variable lifting movement. The difference in the lifts, multiplied by the cross section of the cylinder bore, determines the delivery volume of the pump. A braking force to the oscillating piston eliminated and the velocity of discharge of the medium to be delivered is increased by providing a member 8, whose longitudinal extension between fastening members of the two pump pistons is variable during one pump cycle so as to generate the difference between the heights of lift of the two pistons that are rigidly connected to said fastening members.