Part throttle adjustment

Claim 2

A part throttle adjustment mechanism for a carburetor comprising: a housing having a bore therein exposed at one end to atmosphere and at the other end to a vacuum source, a power piston slidably supported for reciprocation in said bore and having an internal opening therethrough, an adjustment pin located within said opening, means on said piston for locating a metering rod within a metering jet, coacting means on said pin and said piston for adjustably positioning said piston along the length of said pin to adjust the part throttle position of said piston, a compression spring interposed between said adjustment pin and said housing having a fixed height when the piston is maintained in a part throttle position by a first vacuum level at the other end of said bore, said spring moving said piston to a fuel enrichment position in response to a predetermined reduced vacuum at the other end of said bore at all part throttle adjusted positions of said piston to provide extra enrichment of fuel supply through the metering jet.

Claim 3

A part throttle adjustment mechanism for a carburetor operative to supply an air fuel mixture to an internal combustion engine and including a throttle valve operative to vary the vacuum in the intake manifold of the engine comprising: carburetor housing means including a bore therein having one end thereof exposed to atmosphere and the opposite end thereof exposed to intake manifold vacuum, a tubular power piston slidably supported for reciprocation in said bore for separating atmospheric pressure on one end of said piston from vacuum pressure on the opposite end thereof, one end of said power piston being internally threaded, an adjustment pin having a head portion thereon threadably received in the one end of said power piston, a compression spring connected between said pin and said housing means for forcing said piston exteriorly of said bore, means on said power piston for locating a metering rod with respect to a metering jet for controlling fuel supply to the internal combustion engine from an off idle position to wide open throttle operation wherein intake manifold vacuum levels are maintained to subject said piston to a pressure differential thereacross to collapse said spring to hold said power piston in a part throttle control position, means for fixing said power piston against rotation with respect to said bore to permit screw adjustment of said piston with respect to said pin so as to move said piston longitudinally of said bore thereby to adjust the height relationship between the metering rod and the metering jet for varying part throttle fuel flow, said spring having a fixed height relationship between said pin and housiNg when said power piston is in its part throttle control position thereby to maintain a constant spring force on said piston throughout screw adjustment thereof whereby extra mixture enrichment of the vehicle is only obtained when the vacuum within the intake manifold is reduced below a preselected level in response to predetermined increased engine loads.

Claim 4

A part throttle adjustment mechanism for a carburetor operative to supply an air fuel mixture to an internal combustion engine and including a throttle valve operative to vary the vacuum in the intake manifold of the engine comprising: carburetor housing means including a bore therein having one end thereof exposed to atmosphere and the opposite end thereof exposed to intake manifold vacuum, a tubular power piston slidably supported for reciprocation in said bore for separating atmospheric pressure on one end of said piston from vacuum pressure on the opposite end thereof, one end of said power piston being internally threaded, an adjustment pin having a head portion thereon threadably received in the one end of said power piston, a compression spring connected between said pin and said housing means for forcing said piston exteriorly of said bore, means on said power piston for locating a metering rod with respect to a metering jet for controlling fuel supply to the internal combustion engine from an off idle position to wide open throttle operation wherein intake manifold vacuum levels are maintained to subject said piston to a pressure differential thereacross to collapse said spring to hold said power piston in a part throttle control position, means for fixing said power piston against rotation with respect to said bore to permit screw adjustment of said piston with respect to said pin so as to move said piston longitudinally of said bore thereby to adjust the height relationship between the metering rod and the metering jet for varying part throttle fuel flow, said spring having a fixed height relationship between said pin and housiNg when said power piston is in its part throttle control position thereby to maintain a constant spring force on said piston throughout screw adjustment thereof whereby extra mixture enrichment of the vehicle is only obtained when the vacuum within the intake manifold is reduced below a preselected level in response to predetermined increased engine loads.

Claim 5

A part throttle adjustment mechanism for a carburetor having a throttle valve and fuel supply means including a metering jet and a metering rod movable with respect to the metering jet to control fuel supply to the vehicle comprising: housing means having a bore therein exposed at one end to atmosphere and exposed at the other end to a source of vacuum responsive to changes in vehicle operation and having a first vacuum level under part throttle positions and a predetermined reduced vacuum level under heavy acceleration or high speed throttle positions, a power piston supported for reciprocation within said bore for separating the atmospheric and vacuum sides of said bore from one another and maintained by a predetermined intake vacuum in a part throttle position, means on said power piston for supporting a metering rod, means within said power piston including an elongated compression spring for biasing said power piston outwardly of said bore against reduced vacuum on one end thereof, said adjustment mechanism including means coacting with said piston for causing said piston to be adjusted longitudinally of said bore to adjust the part throttle position of the metering rod with respect to the metering jet, and means for supporting said spring at a constant height when said piston is held in its part throttle control position by the first vacuum level to maintain a constant spring force thereon for shifting said piston to a fuel enrichment position in response to a predetermined reduced vacuum throughout the adjusted position of said piston.

Claim 6

A part throttle adjustment mechanism for a carburetor having a throttle valve and fuel supply means including a metering jet and a metering rod movable with respect to the metering jet to control fuel supply to the vehicle comprising: housing means having a bore therein exposed at one end to atmosphere and exposed at the other end to a source of vacuum responsive to changes in vehicle operation and having a first vacuum level under part throttle positions and a predetermined reduced vacuum level under heavy acceleration or high speed throttle positions, a power piston supported for reciprocation within said bore for separating the atmospheric and vacuum sides of said bore from one another and maintained by a predetermined intake vacuum in a part throttle position, means on said power piston for supporting a metering rod, means within said power piston including an elongated compression spring for biasing said power piston outwardly of said bore against reduced vacuum on one end thereof, said adjustment mechanism including means coacting with said piston for causing said piston to be adjusted longitudinally of said bore to adjust the part throttle position of the metering rod with respect to the metering jet, and means for supporting said spring at a constant height when said piston is held in its part throttle control position by the first vacuum level to maintain a constant spring force thereon for shifting said piston to a fuel enrichment position in response to a predetermined reduced vacuum throughout the adjusted position of said piston.

Claim 7

A mechanism for permitting adjustment of a part throttle mechanism in a carburetor having a first control position to limit fuel supply to an internal combustion engine and a second fuel enrichment position to increase the flow of fuel to an internal combustion engine and operative to be moved between the first and second control positions in response to a predetermined reduction in engine intake manifold vacuum comprising: housing means forming a bore opened at one end to atmosphere and at the opposite end thereof to vacuum within an intake manifold, a power piston slidably supported within said bore for separating the atmospheric end thereof from the evacuated end thereof and maintained by a predetermined intake vacuum in a first control position, height adjustment means within said power piston for adjusting said piston with respect to its first control position within said bore to adjust a part throttle position of a metering rod with respect to a metering jet so as to calibrate control of fuel through the metering jet at the part throttle control position, said height adjustment means including spring means for imposing a constant spring force on said piston throughout adjustment of said power piston in its first control position and operative upon a predetermined reduced vacuum on the evacuated end of the power piston to shift the power piston from its first control position to a second control position for locating the rod within the jet to cause enrichment of fuel flow therethrough.

Claim 8

A mechanism for permitting adjustment of a part throttle mechanism in a carburetor having a first control position to limit fuel supply to an internal combustion engine and a second fuel enrichment position to increase the flow of fuel to an internal combustion engine and operative to be moved between the first and second control positions in response to a predetermined reduction in engine intake manifold vacuum comprising: housing means forming a bore opened at one end to atmosphere and at the opposite end thereof to vacuum within an intake manifold, a power piston slidably supported within said bore for separating the atmospheric end thereof from the evacuated end thereof and maintained by a predetermined intake vacuum in a first control position, height adjustment means within said power piston for adjusting said piston with respect to its first control position within said bore to adjust a part throttle position of a metering rod with respect to a metering jet so as to calibrate control of fuel through the metering jet at the part throttle control position, said height adjustment means including spring means for imposing a constant spring force on said piston throughout adjustment of said power piston in its first control position and operative upon a predetermined reduced vacuum on the evacuated end of the power piston to shift the power piston from its first control position to a second control position for locating the rod within the jet to cause enrichment of fuel flow therethrough.

Claim 9

A mechanism for permitting adjustment of a part throttle mechanism in a carburetor having a first control position to limit fuel supply to an internal combustion engine and a second fuel enrichment position to increase the flow of fuel to an internal combustion engine and operative to be moved between the first and second control position in response to a predetermined reduction in engine intake manifold vacuum comprising: housing means forming a bore opened at one end to atmosphere and at the opposite end thereof to vacuum within an intake manifold, a power piston slidably supported wiThin said bore for separating the atmospheric end thereof from the evacuated end thereof and maintained by a predetermined intake vacuum in a first control position, an adjustment pin threadably received by said power piston, means locating said piston against rotation within said bore, said pin being threadable within said piston to the adjust position of said piston on said pin thereby to adjust a part throttle position of a metering rod with respect to a metering jet so as to calibrate the control of fuel through the metering jet at the part throttle control position, a compression spring interposed between said pin and said housing means having a fixed height when said power piston is in its first control position to direct a constant spring force thereon, said spring operative upon a predetermined reduced vacuum on the evacuated end of the power piston to shift the power piston from its first control position to a second control position for locating the metering rod and jet to cause enrichment of fuel flow therethrough.

Claim 10

A mechanism for permitting adjustment of a part throttle mechanism in a carburetor having a first control position to limit fuel supply to an internal combustion engine and a second fuel enrichment position to increase the flow of fuel to an internal combustion engine and operative to be moved between the first and second control position in response to a predetermined reduction in engine intake manifold vacuum comprising: housing means forming a bore opened at one end to atmosphere and at the opposite end thereof to vacuum within an intake manifold, a power piston slidably supported wiThin said bore for separating the atmospheric end thereof from the evacuated end thereof and maintained by a predetermined intake vacuum in a first control position, an adjustment pin threadably received by said power piston, means locating said piston against rotation within said bore, said pin being threadable within said piston to the adjust position of said piston on said pin thereby to adjust a part throttle position of a metering rod with respect to a metering jet so as to calibrate the control of fuel through the metering jet at the part throttle control position, a compression spring interposed between said pin and said housing means having a fixed height when said power piston is in its first control position to direct a constant spring force thereon, said spring operative upon a predetermined reduced vacuum on the evacuated end of the power piston to shift the power piston from its first control position to a second control position for locating the metering rod and jet to cause enrichment of fuel flow therethrough.