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. 29, 1999
Filed:
Sep. 03, 1997
Hiromu Kuromitsu, Chiryu, JP;
Aisin Seiki Kabushiki, Kariya, JP;
Abstract
A plunger pump includes a piston which is driven for reciprocatory motion and associated with a check valve. A space within a cylinder is partitioned by a piston 1p into a first space A which communicates with a discharge port 1ep and a second space B which communicates with a suction port 1ip. To reduce the peak value of a fluctuation in the suction pressure, a third port 2ip communicating with the first space A is added, and the suction port 1ip and the third port 2ip are connected in common to a suction line Pin through check valves 20 and 19, respectively. The first space A has a diameter greater than the diameter of the piston while the second space B has a diameter which is comparable to the diameter of the piston and hence is less than that of the first space A. On the forward stroke of the piston, a braking liquid is drawn into the second space from the suction line Pin. On the return stroke of the piston, a braking liquid is drawn into the first space A from the suction line Pin, and a braking liquid flows from the second space B to the first space A through a center opening in the piston. On the forward stroke of the piston, the braking liquid in the first space A is discharged through a discharge port 1ep. The suction of the braking liquid into the cylinder from the suction line Pin is dispersed between the forward and the return stroke, thus suppressing a peak in the fluctuation in the suction pressure.