Diaphragm vacuum pump

• US 3,981,636 A
• Filed: 11/03/1975
• Issued: 09/21/1976
• Est. Priority Date: 07/20/1973
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kogyo Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kogyo Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Aoki, Shigeru, Sakai, Tosimitu, Suzuki, Katuya
• Primary Examiner(s): Cline, William R.
• Application Number:
  US05/628,403
• Time in Patent Office: 323 Days
• Field of Search: 137/525, 137/525.3, 137/512.15, 137/512.4, 137/516.11, 137/516.13, 417/566
• US Class Current: 417/566
• CPC Class Codes: F04B 39/108 circular reed valves
• CPC Class Codes: F04B 45/04 having plate-like flexible members, e.g. diaphragms F04B45/10 takes precedence
• CPC Class Codes: F04B 9/06 the means including spring- or weight-loaded lost-motion devices
• CPC Class Codes: F16K 15/1402 having an integral flexible member cooperating with a plurality of seating surfaces
• CPC Class Codes: Y10T 137/784 Integral resilient member forms plural valves
• CPC Class Codes: Y10T 137/786 Concentric ports

Abstract

To suck and discharge the air into and from a pressure reducing chamber of a vacuum pump, a check valve comprises a valve body made of plastic material in a mushroom configuration, and a plate member which includes a flat valve seat surface to be engaged with the annular rim of the cap portion of the valve body, an assembling hole to be coupled with the neck portion of the valve body, and a plurality of openings positioned symmetrically on a circle concentric with the assembling hole to normally be closed by the cap portion of the valve body. The neck portion of the valve body is assembled with the assembling hole under axially and radially compressed condition to air-tightly engage the annular rim of the cap portion of the valve body on the valve seat surface.

Claims

1. A diaphragm vacuum pump having a plurality of check valves for allowing flow into and out from a suction chamber having a diaphragm-piston assembly for creating suction therein wherein each check valve comprises:

a valve body made of plastic material in a mushroom configuration having a circular cap and a neck portion including an annular groove,

a plate member including a flat valve seat surface to be engaged with the annular rim of the cap portion of said valve body,

a circular assembling hole to be coupled with the neck portion of said valve body, and

a plurality of circular openings disposed symmetrically on a circular path concentric with said assembling hole so as to be normally closed by the annular rim of the cap portion of said valve body, the neck portion of said valve body being assembled within said assembling hole so that said groove is registered with said assembling hole through said plate, said neck portion being under an axially and radially compressed condition to air-tightly engage the annular rim of the cap portion of said valve body against said valve seat surface of said plate member, the ratio of the radius of said circular path to the radius of the cap portion of the valve body being in the range from about 0.5 to about 0.65, the ratio of the width of said plate to the width of said annular groove being in the range from about 1.2 to about 1.4, and the ratio of the diameter of the assembling hole to the normal diameter of the neck portion of the valve body being about equal to or less than 1.1.

2. A check valve as set forth in claim 1, wherein said valve body is made of soft synthetic resin.

3. A check valve as set forth in claim 1, wherein said valve body is made of synthetic rubber.

4. A check valve as set forth in claim 1, wherein said plate member is made of hard synthetic resin.

5. A check valve as set forth in claim 1, wherein said plate member is made of Nylon.

6. A check valve as set forth in claim 1, wherein said plate member is made of polyethylene.

7. A check valve as set forth in claim 1, wherein said plate member is made of polytetrafluoroethylene.

8. A check valve as set forth in claim 1, wherein said plate member is made of brass, and said valve seat surface being finished by buff-polishing.