×

Electromagnetic pump

  • US 4,021,152 A
  • Filed: 05/10/1976
  • Issued: 05/03/1977
  • Est. Priority Date: 12/06/1974
  • Status: Expired due to Term
First Claim
Patent Images

1. An electromagnetic pump comprising a pump body, a cylinder, a pressure chamber, a suction valve and a discharge valve communicating with the pressure chamber, an electromagnetic coil mounted concentrically with an extension line of the longitudinal axis of said cylinder, a plunger case disposed within said electromagnetic coil, a delivery plunger and an electromagnetic plunger fitted in said cylinder and said plunger case, respectively, for reciprocating sliding movement and in abutting engagement with each other, said plungers being retained in pressure engagement between springs, characterized by a pressure adjusting cylinder provided within said pump body and including means communicating said pressure adjusting cylinder with the suction and delivery sides of the pump, a pressure adjusting plunger fitted within said pressure adjusting cylinder for reciprocating sliding movement and with an extremely small clearance between the outer diameter of the pressure adjusting plunger and the inner diameter of the pressure adjusting cylinder in a range where the sliding movement thereof is not prevented, said pressure adjusting plunger having at the top end thereof a valve body which engages a valve seat at an end of a passage connecting the delivery side of the pump with the pressure adjusting cylinder to thereby constitute a check valve, and said pressure adjusting plunger also having a shoulder portion at the top end thereof to thereby constitute a variable orifice relief throttle valve in the form of piston-valve together with a relief port perforated through the side wall of said pressure adjusting cylinder, said pressure adjusting plunger having said check valve and said relief throttle valve constituted separately, a pressure adjusting spring biasing the pressure adjusting plunger so as to close said check valve and said relief throttle valve, whereby said check valve is first opened in a process of rising in pressure in said passage after operation of the pump and on exceeding a predetermined pressure, said variable orifice relief throttle valve operates to adjust the opening degree of the orifice and relief port to thereby control the amount of leak from the delivery side of the pump through said passage, past said check valve and through said relief port so that the delivery pressure of the pump may be maintained at predetermined value, whereas from the time said check valve is opened till immediately before said variable orifice relief valve is opened, the pressure adjusting plunger moves in reciprocating movement by the extension and contraction of the pressure adjusting spring to thereby level the delivery pulsation of the pump and operate as an accumulator performing a pressure accumulating action.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×