Patent ID: 7094041
Filing Date: 2006-08-22
Classification: F04B

Abstract:
1. An electromagnetically driven plunger pump, comprising: a cylindrical body defining a passage for a liquid; a plunger, having a passage extending therethrough, reciprocally disposed in said passage defined by said cylindrical body and having intimate contact therewith, said plunger being free to reciprocate within a specific range; a feeding spring for exerting an urging force against said plunger in a first direction; a first check valve for opening and closing said passage extending through said plunger; a chamber on a downstream side of said first check valve; a second check valve on a downstream side of said chamber; a first spring for exerting an urging force against said second check valve for preventing flow of the fluid from said chamber; a second spring, surrounding said feeding spring, for exerting an urging force against said plunger in a second direction opposite the first direction; and a magnetic circuit including a solenoid coil for applying a thrust to said plunger so as to move said plunger in the second direction, such that