US4079719A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Timing control for fuel pump
Assignee: Stanadyne LLC
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Filing: 1976-03-26
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Granted: 1978-03-21
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Expires: 1996-03-26
Abstract
Abstract A fuel injection pump including a charge pump for delivering discrete pulses of high pressure liquid fuel sequentially to the several cylinders of an associated engine is provided with an angularly adjustable cam ring to control the timing of the pumping strokes. The position of the cam ring is controlled by an advance piston, the position of which is controlled by a hydraulic pressure correlated with engine speed. A load sensing piston, engageable with one end of the advance piston above a fixed amount of timing advance, is subjected to the pressure of the metered fuel down-stream of the metering valve which controls the quantity of fuel delivered by the pump to urge the advance piston in a direction to retard the timing of the pumping strokes to result in a timing control system in which the timing is more advanced at high speeds and light load than it is at high speeds and full load.
Inventors
- 👤 Ellis Varcoe
- 👤 William Walter Tease
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:30
CPC Classifications
F; F02; F02M; F02M41/00; F02M41/08; F02M41/14; F02M41/1405; F02M41/1411; F02M41/1416
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
200 words
A fuel injection pump comprising a cam, pump plungers movable relative to the cam to translate the contour of the cam to sequential pumping strokes, a first source of fluid under a pressure correlated with the speed of the associated engine, an advance piston connected to said cam for adjusting its relative angular position to control the timing of the pumping strokes, a first hydraulic chamber at one end of said advance piston connected to said first source of fluid to move the advance piston to advance the timing in response to increased engine speed, a biasing spring biasing said advance piston in a direction in opposition to said first source of fluid, a second movable piston at the other end of the advance piston, a second source of fluid under a pressure correlated with engine operating condition other than speed, a second hydraulic chamber at the end of said second piston connected to said source of fluid, and a stop for limiting the movement of said second piston in the direction to retard timing, said second piston engaging the end of the advance piston opposite said first hydraulic chamber when a predetermined amount of advance in timing is reached.
Claim 2
Dependent Claim
200 words
A fuel injection pump comprising a cam, pump plungers movable relative to the cam to translate the contour of the cam to sequential pumping strokes, a first source of fluid under a pressure correlated with the speed of the associated engine, an advance piston connected to said cam for adjusting its relative angular position to control the timing of the pumping strokes, a first hydraulic chamber at one end of said advance piston connected to said first source of fluid to move the advance piston to advance the timing in response to increased engine speed, a biasing spring biasing said advance piston in a direction in opposition to said first source of fluid, a second movable piston at the other end of the advance piston, a second source of fluid under a pressure correlated with engine operating condition other than speed, a second hydraulic chamber at the end of said second piston connected to said source of fluid, and a stop for limiting the movement of said second piston in the direction to retard timing, said second piston engaging the end of the advance piston opposite said first hydraulic chamber when a predetermined amount of advance in timing is reached.
Claim 3
Dependent Claim
197 words
A fuel injection pump comprising a cam, pump plungers movable relative to the cam to translate the contour of the cam to sequential pumping strokes, a first source of fluid under a pressure correlated with the speed of the associated engine, an advance piston connected to said cam for adjusting its relative angular position to control the timing of the pumping strokes, a first hydraulic chamber at one end of said advance piston connected to said first source of fluid to move the advance piston to advance the timing in response to increased engine speed, a biasing spring biasing said advance piston in a direction in opposition to said first source of fluid, a second movable piston at the other end of the advance piston, a second source of fluid under a pressure correlated with engine operating condition other than speed, a second hydraulic chamber at the end of said second piston connected to said source of fluid, said second piston being operatively connected to said advance piston to move said advance piston in the direction to retard timing, and a stop for limiting the movement of said second piston in the direction to retard the timing.
Claim 4
Dependent Claim
197 words
A fuel injection pump comprising a cam, pump plungers movable relative to the cam to translate the contour of the cam to sequential pumping strokes, a first source of fluid under a pressure correlated with the speed of the associated engine, an advance piston connected to said cam for adjusting its relative angular position to control the timing of the pumping strokes, a first hydraulic chamber at one end of said advance piston connected to said first source of fluid to move the advance piston to advance the timing in response to increased engine speed, a biasing spring biasing said advance piston in a direction in opposition to said first source of fluid, a second movable piston at the other end of the advance piston, a second source of fluid under a pressure correlated with engine operating condition other than speed, a second hydraulic chamber at the end of said second piston connected to said source of fluid, said second piston being operatively connected to said advance piston to move said advance piston in the direction to retard timing, and a stop for limiting the movement of said second piston in the direction to retard the timing.
Claim 5
Dependent Claim
24 words
The fuel injection pump of claim 2 wherein said stop also serves to limit the maximum advance of the timing of the pumping stroke.
Claim 6
Dependent Claim
33 words
The fuel injection pump of claim 3 wherein the pump includes a metering valve for controlling the quantity of fuel delivered by the pump and metered fuel is the second source of fluid.
Claim 7
Dependent Claim
22 words
The fuel injection pump of claim 2 wherein a trimmer spring is provided to modify the operation of the load sensing piston.
Claim 8
Dependent Claim
36 words
The fuel injection pump of claim 2 wherein a compression spring operatively connects said second piston and said advance piston to apply a biasing force correlated with said second engine operating condition under all operating conditions.
Claim 9
Dependent Claim
22 words
The fuel injection pump of claim 1 wherein said advance piston and said second piston have approximately the same cross sectional area.
Claim 10
Dependent Claim
33 words
The fuel injection pump of claim 1 wherein the pump includes a metering valve for controlling the quantity of fuel delivered by the pump and metered fuel of the second source of fluid.
References Cited (Backward Citations)
US2660992A
Cited
US3051154A
Cited
US3116728A
Cited
US3394688A
Cited
US3433159A
Cited
US3771506A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-20 | 1981-09-19 | 1982-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-20 | 1985-09-19 | 1986-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-20 | 1989-09-19 | 1990-03-21 | $7700.00 | Window Closed / Lapsed |