Patent US3871345A successfully refreshed from Google Patents.
US3871345A
Expired / Lapsed
US
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Fuel injection pump with improved return flow conduit
Assignee: Motorenfabrik Hatz GmbH and Co KG
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Filing: 1973-08-07
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Granted: 1975-03-18
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Expires: 1993-08-07
Abstract
Abstract In an injection internal combustion engine having a fuel injection pump, wherein the fuel passes by gravity flow from a supply container through an admission conduit to the injection pump, at least one return flow conduit separate from the admission conduit is provided for superfluous fuel which has entered the pump which has not been injected, this return conduit leading from the injection pump to the supply container, and being equipped with a valve which is preferably of the non-return type, but which, when it is in its seated position, allows a small flow of fuel between the return flow conduit and the injection pump. The superfluous or non-injected fuel thus does not pass back into the admission conduit. The valve construction may be of various types so long as it permits the small flow of fuel when the valve member is in its seated or relatively closed position.
Inventors
- 👤 Ernst Hatz
- 👤 Erhard Oertel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:42
CPC Classifications
F; F02; F02M; F02M55/00; F02M55/007; F02B; F02B3/00; F02B3/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
136 words
In an injection internal combustion engine with at least one fuel injection pump, wherein the fuel passes by gravity flow from a supply container through an admission conduit to a suction chamber of the injection pump, the improvement comprising at least one return flow conduit separate from the admission conduit for superfluous fuel which has not been injected, said return flow conduit leading from the suction chamber of the injection pump to the supply container, and valve means for controlling flow through said return flow conduit to the supply container, said valve means allowing even in its seated position a small flow of fuel such that at least a small flow of fuel is feasible between the return flow conduit and the suction chamber of the injection pump in each operational stage of the injection pump.
Claim 2
Dependent Claim
136 words
In an injection internal combustion engine with at least one fuel injection pump, wherein the fuel passes by gravity flow from a supply container through an admission conduit to a suction chamber of the injection pump, the improvement comprising at least one return flow conduit separate from the admission conduit for superfluous fuel which has not been injected, said return flow conduit leading from the suction chamber of the injection pump to the supply container, and valve means for controlling flow through said return flow conduit to the supply container, said valve means allowing even in its seated position a small flow of fuel such that at least a small flow of fuel is feasible between the return flow conduit and the suction chamber of the injection pump in each operational stage of the injection pump.
Claim 3
Dependent Claim
91 words
An injection internal combustion engine according to claim 1, wherein said injection pump is a piston injection pump, the piston of which is arranged in a piston bush provided with a return flow duct communicating with the suction chamber, the excess fuel not injected passing out through the return flow duct into the suction chamber of the pump, the return flow conduit being connected to the suction chamber, and the opening of the return flow conduit into the chamber being disposed approximately opposite the return flow duct in the piston bush.
Claim 4
Dependent Claim
31 words
An injection internal combustion engine according to claim 2 wherein said valve is a non-return valve and is located in the immediate vicinity of the mouth of the return flow conduit.
Claim 5
Dependent Claim
69 words
An injection internal combustion engine according to claim 3 wherein said non-return valve comprises a valve ball which cooperates with a valve seat in the return flow conduit, said valve ball having a plurality of narrow ducts at least one of which at any time provides a small conducting connection between the return flow conduit and the suction chamber when the valve ball is applied against the valve seat.
Claim 6
Dependent Claim
67 words
An injection internal combustion engine according to claim 3 wherein the non-return valve comprises a valve ball which cooperates with a valve seat in the return flow conduit, a number of grooves of small cross section being provided in the valve seat to furnish a small conducting connection between the return flow conduit and the suction chamber even when the valve ball is applied against its seat.
Claim 7
Dependent Claim
39 words
An internal combustion engine according to claim 4 wherein the valve ball has no return spring acting thereon and has a degree of play within the return flow conduit bounded by a limit abutment spaced from the valve seat.
Claim 8
Dependent Claim
20 words
An injection internal combustion engine as claimed in claim 4 wherein the valve ball is made of a synthetic material.
Claim 9
Dependent Claim
88 words
An injection internal combustion engine as claimed in claim 1 wherein said valve is of the non-return type, the valve seat of the non-return valve being provided in a coupling nipple which attaches the admission conduit to the casing of the injection pump, a coupling piece being provided on the coupling nipple for coupling the return flow conduit thereto, said coupling nipple having a portion spaced from the valve seat and acting as a limit stop for the non-return valve when the valve is in its raised condition.
Claim 10
Dependent Claim
68 words
An injection internal combustion engine as claimed in claim 8, wherein said non-return valve includes a valve ball associated with a conical valve seat in said couping nipple, at least one recess in the valve seat providing a conducting connection between the injection pump and the admission conduit, on the one hand, and the return flow conduit, on the other hand, even when the valve ball is seated.
Claim 11
Dependent Claim
56 words
An injection internal combustion engine according to claim 9 wherein at least one recess is provided in the portion of the coupling piece for the return flow conduit confronting said ball valve, this recess providing a conducting connection between the injection pump and the return flow conduit when the valve ball is in its raised condition.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |