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Publication numberUS3469825 A
Publication typeGrant
Publication dateSep 30, 1969
Filing dateOct 12, 1967
Priority dateOct 12, 1967
Publication numberUS 3469825 A, US 3469825A, US-A-3469825, US3469825 A, US3469825A
InventorsChester Dubois
Original AssigneeOutboard Marine Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Alignment bushing for needle valve
US 3469825 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

P 30, 1969 c. DU BOIS 3,469,825

ALIGNMENT BUSHING FOR NEEDLE VALVE Filed Oct. 12, 1967 V w V /o) 1 v 4 l2 20 a2 22 24 27 /9 Z9 Z5 F INVIN'T'QZ 674:3 r-Ee Du 50 5 ATTORN United States Patent 3,469,825 ALIGNMENT BUSHING FOR NEEDLE VALVE Chester DuBois, Zion, Ill., assignor to Outboard Marine Corporation, Waukegan, 11]., a corporation of Delaware Filed Oct. 12, 1967, Ser. No. 674,854 Int. Cl. F02m 19/04, 19/06 US. Cl. 261-71 4 Claims ABSTRACT OF THE DISCLOSURE Disclosed herein is a resilient alignment bushing for the needle valve of a carburetor. The bushing comprises concentric inner and outer surfaces with the inner surface defining an axial aperture which receives the needle valve and maintains the valve member in concentric relation to the valve seat. The outer surface of the bushing engages the bore in the carburetor housing to afford a fluid seal.

BACKGROUND OF INVENTION The invention relates to needle valves used to adjust fluid flow in carburetors and more particularly to an alignment bushing for such needle valves. The accepted manufacturing tolerances observed in carburetor construction are such that vibratory movement between the needle point and the needle seat is possible as a result of normal engine vibrations. Such vibratory movement can result in interference with consistent metering of the fluid flow through the valve and wear of the needle portion and valve seat.

SUMMARY OF INVENTION The invention provides an alignment bushing for a needle valve of a carburetor to minimize vibratory movement between the needle valve and the needle seat and to minimize wear of the needle portion and seat. The bushing of the invention has concentric inner and outer surfaces with the outer surface engaging the bore in the valve housing in which the valve body is located and the inner surface engaging the needle valve member. The concentric relationship between the inner and outer surfaces is maintained by a nondeformable barrier between the wall portions providing such outer and inner surfaces. The fit of the bushing and the valve bore and valve member also affords a fluid seal between the bore and the fluid passage and axial movement of the valve member within the bore. The alignment bushing is desirably constructed of a resilient material such as nylon.

The object of this invention is to provide a device that will reduce the vibratory movement to an acceptable minimum by maintaining the concentricity between the needle point and the seat yet allow manufacturing tolerances that are economical to produce.

Another object of this invention is to improve the metering consistency by maintaining a more stable relationship between the needle point and the needle seat which will then be substantially immune to the adverse effects of vibration. Another object is to provide an effective seal against leakage to the atmosphere between the needle valve threads and the fuel passage.

Further objects and advantages of the invention will become apparent from the following disclosure.

DRAWINGS FIGURE 1 is an enlarged vertical sectional view of a carburetor embodying the present invention.

FIGURE 2 is an enlarged sectional view of the alignment bushing shown in FIGURE 1.

FIGURE 3 is a partially broken away perspective view of the alignment bushing shown in FIGURE 1.

DETAILED DESCRIPTION In the drawings there is shown a carburetor which is generally designated 10 and which includes a carburetor body or housing 12, a mixing chamber 14, a float chamber 16 and a fluid passage 18 connecting the float chamber 16 with the mixing chamber 14. Flow of fluid through the fluid passage 18 from the float valve to the mixing chamber is controlled or metered by a valve 19 which includes a valve body 20 located in a bore 21 defined by the wall 23 of the bore 21 in the carburetor housing 12. The bore 21 communicates with the fluid passage 18.

The valve body 20 has a valve member or needle portion 22 which includes a tip and shank, the tip being located for cooperation with a restricted portion in the fluid passage 18, which portion forms a valve seat 24. Adjustment of the valve body axially is aflorded by a threaded portion 25 of the valve body located at one end of the valve body stem 26. The threaded portion is received in a threaded bore of a nut 27. A gasket 29 is conventionally provided to maintain a seal.

The invention contemplates the reduction of wear of the needle portion 22 and the valve seat 24 caused by vibratory movement of the needle portion as a result of engine vibration, thus aifording consistent metering 0f flow through the fluid passage 18. In this regard, means are provided for maintaining the valve needle portion 22 in concentric relation to and centered within the valve seat 24 to minimize contact caused by vibratory move ment. In the construction disclosed in FIGURES 1 through 3 the means comprises a bushing 32 which is desirably constructed of a resilient material such as nylon and is in the form of a large frustoconical wall portion 33 and a small frustoconical wall portion 34 with an outside diameter less than the outside diameter of the first wall portion. The wall portion 34 is located at one end of the wall portion 33 and in concentric relation therewith. The wall portions 33, 34 are connected at juncture 35 and define an axial aperture 36 through which the valve body 20 extends.

The juncture 35 between the wall portions 33 and 34 is equal in thickness to the combined thickness of each of the wall portions 33 and 34 and forms a nondeformable barrier which serves to maintain the concentric relationship between surfaces 37 and 38 notwithstanding radial compression of wall portion 33 as it is inserted in bore 21 or radial expansion of wall portion 34 when the needle portion 22 is extended through the bushing 32. Thus, the fit of the Wall portion 34 with the shank of the needle portion 22 is independent of the fit of the wall portion 33 with the wall of the bore 21.

A fluid seal between the fluid passage 18 and the bore 21 is afforded 'by the fit between surface 37 and bore wall 23 and the shaft seal between the shank of needle portion 22 and the surface 38.

The frustoconical shape of the bushing shown in FIG- URES 1 through 3 facilitates insertion of the bushing in the valve chamber and prevents movement of the bushing 32 relative to the bore 21.

FIGURE 4 shows a modified embodiment of the invention. In this embodiment the means for maintaining concentricity of the needle valve member 22 with respect to the seat 24 is in the form of a bushing 40 having a frustoconical outer wall 42 which tapers inwardly toward the valve seat and an inverted frustoconical inner wall 44 which tapers inwardly toward the valve body 20. The

Patented Sept. 30, 1969 juncture 45 between wall portion 42 and wall portion 44 is at the end of the bushing adjacent the fluid passage 18. The outer surface 46 of the wall portion 42 engages the wall 23 of the bore 21 and the inner surface 47 of the wall 44 engages the shank of the needle portion 22. The wall portions 42 and 44 are in concentric relation and maintain such relation when compressed upon insertion in the valve bore 21.

A further embodiment of the invention is illustrated in FIGURE 5. In this embodiment the alignment :bushing comprises an annulus or O-ring 48 which has an outer surface 49 in engagement with the bore wall 23 and an inner surface 50 in engagement with the needle portion 22.

Although several embodiments of the invention are disclosed herein, the use in connection with a carburetor needle valve of any resilient bushing which can maintain the concentrieity of its inner and outer walls upon being slightly compressed and seal the fluid assage from the bore is within the purview of the invention.

Various of the features of the invention are set forth in the following claims.

What is claimed is:

1. In a carburetor having a housing with a mixing chamber, a fluid passage having a valve seat in said housing, said fluid passage connecting a fluid source with said mixing chamber, a bore in said housing communicating with said fluid passage, and a valve member adjustably movable axially within said bore for cooperation of said valve member with said valve seat to meter fluid flow through said fluid passage into said carburetor mixing chamber, the improvement comprising a bushing having a frustoconical wall portion with an outer surface engaging said bore, a second frustoconical wall portion at one end of said first wall portion and in concentric relation to said first wall portion and having an outside diameter less than said first frustoconical portion, said first and second wall portions having inner surfaces defining an axial aperture, said valve member extending through said axial aperture, and said inner surface of said second wall portion engaging said valve member.

2. The improvement of claim 1 wherein said first and second fmstoconical wall portions are joined by a juncture which is thicker than each of said wall portions to aflord a barrier against deformation of said second portion upon compression of said first portion.

3. A carburetor comprising a housing having a mixing chamber, a fluid passage in said housing communicating with said mixing chamber, said fluid passage having a restriction forming a valve seat, a bore in said housing communicating with said fluid passage and concentric to said valve seat, a valve body in said bore with a valve member movable axially within said bore and said fluid passage to cooperate with said valve seat to meter flow through said fluid passage, a bushing in said bore, said bushing having a frustoconcial outer wall portion tapering toward said valve member, and a frustoconical inner wall portion concentric to said outer wall portion and connected thereto at the end of said outer wall portion adjacent said valve member, said inner wall portion tapering toward said valve member in the direction converse to said direction of taper of said outer wall portion to define an axial aperture which receives said valve member and interfits therewith to afford axial movement of said valve member and a fluid seal between said fluid passage and said bore,

4. A carburetor in accordance with claim 3 wherein said inner and outer concentric wall portions are connected by a nondeformable barrier.

References Cited UNITED STATES PATENTS 2,840,359 6/ 1958 Cornelius.

2,841,429 7/ 1958 McCuistion.

2,918,973 12/1959 Ozinga 277-212 X 2,970,649 2/1961 Brown 277-212 X 3,125,084 3/1964 Hall 261-69 X 3,126,795 3/ 1964 Kesselring.

3,157,170 11/1964 Reid.

3,192,942 7/1965 Manor et al 251-214 X 3,231,250 1/1966 Kalert 261-71 X 3,240,230 3/1966 Callahan et a1. 251-214 3,330,545 7/1967 Donovan.

TIM R. MILES, Primary Examiner US. Cl. X.R. 251-214; 277-212

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Referenced by
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US3807707 *Jan 2, 1973Apr 30, 1974Johnson HExterior adjustment metering jet insert plate for carburetors and carburetor modifying method
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U.S. Classification261/71, 277/549, 277/910, 261/DIG.380, 251/214, 277/647
International ClassificationF02M7/18, F02M19/04
Cooperative ClassificationF02M7/18, Y10S277/91, F02M19/04, Y10S261/38
European ClassificationF02M7/18, F02M19/04