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Publication numberUS3730495 A
Publication typeGrant
Publication dateMay 1, 1973
Filing dateJul 15, 1971
Priority dateJul 15, 1971
Publication numberUS 3730495 A, US 3730495A, US-A-3730495, US3730495 A, US3730495A
InventorsC Elam
Original AssigneeGen Motors Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Carburetor accelerator pump
US 3730495 A
An easily serviceable carburetor accelerator pump unit incorporates a shield rolled over the outer rim of a rolling diaphragm and having a plurality of inwardly extending members to limit upward travel of a plunger head carried by the diaphragm.
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Description  (OCR text may contain errors)

United States Patent 1191 Elam 1451 May 1, 1973 CARBURETOR ACCELERATOR PUMP Charles F. Elam, Rochester, NY.

General Motors Detroit, Mich.

Filed: July 15,1971

Appl. No.: 162,928


Assignee: Corporation,

US. Cl ..261/34 A, 92/98 D, 92/99, 417/471 Int. Cl ..F02m 7/08 Field of Search ..261/34 A; 92/98 D, 92/99; 417/471 [56] References Cited UNITED STATES PATENTS 2,035,636 3/1936 Chandler ..26l/34 A Schweiss ..26l/34 A Carlson ...261/34 A Ferguson ..92/98 D Bowerman et a1 ..92/98 D Primary Examiner--Tim R-. Miles Attorney-J. L. Carpenter et a1.

ABSTRACT v An easily serviceable carburetor accelerator pump unit incorporates a shield rolled over the outer rim of a rolling diaphragm and having a plurality of inwardly extending members to limit upward travel of a plunger head carried by the diaphragm.

2 Claims, 1 Drawing Figure PATENTEDIAY Hm INXENTOR. Char/e5 1'' 6/021:

. ATTORNEY CARBURETOR ACCELERATOR PUMP A prior art carburetor accelerator pump proposal 7 uses a rolling diaphragm as a pumping member but does not provide an easily serviceable assembly because the rolling diaphragm is secured in the accelerator pump well only during final carburetor assembly. In addition, the prior art proposal does not provide means for limiting unrolling of the diaphragm to prevent rupture of the diaphragm material.

This invention obviates these disadvantages by providing a separate shield member which surrounds the diaphragm and is secured to its outer rim. The shield member is pressed into the accelerator pump well where it is retained during normal operation but from which it may be extracted for service replacement. The upper end of the shield has a plurality of inwardly extending members which overlie the plunger head to limit upward movement of the plunger head and prevent rupture of the diaphragm.

The details as well as other objects and advantages of this invention are set forth below and are shown in the drawing which is an elevational view of a carburetor, shown partially in section to depict the details of the accelerator pump structure.

Referring to the drawing, a carburetor 10 has a mixture conduit 12 in which a throttle 14 is disposed on a shaft 16. A throttle lever 18 secured on shaft 16 actuates a link 20 which, upon throttle opening movement, causes clockwise movement of an intermediate lever 22. A cam surface 24 on intermediate lever 22 drives a pump lever 26 counterclockwise to depress a pump rod 28.

The spherically contoured lower end 30 of rod 28 is received in a spherical depression 32 in an accelerator pump plunger head 34. The movable inner rim 36 of a rolling diaphragm 38 is secured about a land 40 of plunger head 34. The stationary outer rim 42 of rolling diaphragm 38 is retained by a rolled-over portion 44 of a cylindrical shield 46. The upper end of shield 46 has three inwardly extending members 48 which overlie plunger head 34 as shown in the drawing.

Shield 46, with diaphragm 38 and plunger head 34 assembled thereto, is pressed into and retained in an accelerator pump well 50 formed in the fuel bowl portion 52 of carburetor 10. The lower end 44 of shield 46 abuts an annular ledge 54 formed in accelerator pump well 50.

A cross passage 56 extends from the bottom of well 50, past a pump inlet passage 58, to pump outlet passage 60. As the throttle is closed, the link and lever mechanism connection to throttle l4 permits upward movement of plunger head 34 by a biasing spring 62, and fuel is drawn into well 50 from fuel bowl 52 through passage 58, past a check valve 64, and through cross passage 56. As the throttle is opened, the downward movement of plunger head 34 caused by the link and lever mechanism discharges fuel from well 50 into cross passage 56, a vent ball check valve 65 closes the vapor vent passage 66 extending through plunger head 34, inlet ball check valve 64 is seated, a discharge ball check valve 67 is lifted, and fuel is discharged through an outlet tube 68 and discharge orifices 70 and 72 into mixture conduit 12. (It will be appreciated that the end 74 of cross passage 60 is plugged after drilling of cross passage 56.)

The easy serviceability of the accelerator pump assembly is evident from the foregoing. Should the accelerator pump diaphragm malfunction, the air horn section 76 of the carburetor 10 may be removed from the fuel bowl section 78, the shield-diaphragm-plunger head assembly withdrawn from accelerator pump well 50, and a replacement shield-diaphragm-plunger head assembly inserted without necessitating substantial disassembly of the carburetor or the accelerator pump mechanisms.

1 claim:

1. A carburetor accelerator pump assembly comprismg:

a rolling diaphragm having a stationary outer rim and a movable inner rim,

a plunger head secured to the inner rim of said diaphragm,

and a cylindrical shield surrounding said diaphragm; said shield having one end rolled radially inwardly over and retaining the outer rim of said diaphragm, said shield further having a member at the other end extending radially inwardly to overlie and retain said plunger head.

2. An accelerator pump for a carburetor having a fuel bowl, means defining a cylindrical accelerating well having an annular radially inwardly extending ledge formed therein, means for conveying fuel from said bowl to said well, a mixture conduit, means for conveying fuel from said well to said mixture conduit, and an accelerator pump actuating member, said accelerator pump comprising:

a rolling diaphragm disposed in said well and having a stationary outer rim disposed adjacent said ledge and having a movable inner rim,

a cylindrical shield received in said well and surrounding said diaphragm, said shield having a lower end rolled radially inwardly over and retaining said stationary rim of said diaphragm, said lower end abutting said annular ledge formed in said well, I

a plunger head disposed within said well and secured to said inner rim of said diaphragm,

and spring means biasing said plunger head upwardly in said well, said plunger head being operable against the bias of said spring means by said actuating member,

the upper end of said shield further having a plurality of radially inwardly extending members overlying said plunger head to limit upward movement of said plunger head.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2035636 *Apr 1, 1935Mar 31, 1936Chandler Milton ECarburetor
US2189554 *Jan 16, 1939Feb 6, 1940Carter Carburetor CorpCarburetor accelerating pump
US2493804 *Aug 17, 1945Jan 10, 1950Carter Carburetor CorpCarburetor accelerating pump
US2687146 *Nov 17, 1950Aug 24, 1954Anderson Products IncBellows for radiator valves
US3163274 *Dec 26, 1962Dec 29, 1964Bowerman Hulie EFluid actuator for clutch or brake
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4064201 *Aug 12, 1976Dec 20, 1977Honda Giken Kogyo Kabushiki KaishaAccelerating pump actuating device for a caburetor
US4322201 *Sep 21, 1979Mar 30, 1982Avi, Inc.IV Pump with back pressure control
US4362673 *Jul 24, 1981Dec 7, 1982Pierburg Gmbh & Co. KgMounting a piston in an accelerator pump of a carburetor and associated method
US4382753 *Sep 10, 1980May 10, 1983Avi, Inc.Nonpulsating IV pump and disposable pump chamber
US4391600 *Sep 15, 1980Jul 5, 1983Avi, Inc.Nonpulsating IV pump and disposable pump chamber
US4410322 *Sep 10, 1980Oct 18, 1983Avi, Inc.Nonpulsating TV pump and disposable pump chamber
US4481914 *Sep 30, 1982Nov 13, 1984Suzuki Jidosha Kogyo Kabushiki KaishaAccelerator pump system for carburetors
US5363743 *Apr 14, 1993Nov 15, 1994Eaton CorporationFluid pressure servomotor
US6293524 *Jan 20, 2000Sep 25, 2001Walbro Japan, Inc.Carburetor with accelerating device
US7717403 *Feb 25, 2008May 18, 2010Walbro Engine Management, L.L.C.Accelerator device for a carburetor
DE2909661A1 *Mar 12, 1979Sep 18, 1980Pierburg Gmbh & Co KgVergaser fuer verbrennungsmotoren
WO1982003246A1 *Mar 15, 1982Sep 30, 1982Luzardo Sebastian Ruben BentancorImprovement in high pressure double action pumps
U.S. Classification261/34.2, 92/99, 417/471, 92/98.00D, 261/DIG.810
International ClassificationF02M7/08
Cooperative ClassificationY10S261/81, F02M7/08
European ClassificationF02M7/08