US3782864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel injector
Assignee: Cummins Inc
•
Filing: 1970-12-30
•
Granted: 1974-01-01
•
Expires: 1990-12-30
Abstract
Abstract A fuel injector for injecting fuel into a cylinder of an internal combustion engine is disclosed, wherein fuel is received from a variable pressure fuel supply and is supplied to a chamber in the injector, the injector also having spray holes for discharging fuel from said chamber to the cylinder. A reciprocable plunger in the injector is utilized to decrease the volume of the chamber and thus increase the pressure of the fuel therein. A pressure actuated valve in the chamber serves to permit fuel injection through the spray holes only when the pressure in the chamber, due to movement of the plunger, reaches a predetermined value sufficient to open the valve. The injector also includes a connection between the chamber and a low pressure zone or drain during part of the cycle of movement of the plunger. This connection permits fuel to be sucked into the chamber during said part of the cycle from the drain rather than from the supply. Since the plunger does not suck fuel from the supply, the quantity of fuel entering the chambe from the supply will be a function of the pressure of the fuel delivered by the supply.
Inventors
- 👤 J Perr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:56
CPC Classifications
F; F02; F02M; F02M57/00; F02M57/02
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
411 words
An injector for injecting fuel into a cylinder of an internal combustion engine, comprising an injector body having a fuel injection chamber provided with an opening adapted to communicate with said cylinder, a valve member in said body and normally closing said opening, said valve member being movable to a position permitting fuel flow from said fuel injection chamber through said opening when the pressure of the fuel in said fuel injection chamber reaches a predetermined value, fluid displacement means movably mounted in said injector body and defining a receiving chamber therein, said injector body also having a connecting passage connecting said receiving chamber with said fuel injection chamber and a supply passage adapted to connect said receiving chamber with a source of fuel under variable pressure for supplying varying quantities of fuel to said receiving chamber, the volume of said receiving chamber being determined by the extent of movement of said fluid displacement means and limited to a predetermined maximum when said fluid displacement means is moved fully in one direction, and said fluid displacement means being movable in the opposite direction to reduce the volume of said receiving chamber and increase the pressure therein and thereby move said valve member to an open position whereby a quantity of fuel from said fuel injection chamber is injected through said opening into said cylinder, said injector body having a bore therein, said fluid displacement means comprising a piston and a reciprocable plunger in said bore, and said plunger being operable to move said piston in said opposite direction, said receiving chamber being located between said piston and one end of said bore, said plunger having a reduced diameter portion defining a space in said bore and a duct therein having one end communicating with said plunger bore between said plunger and said piston, said one end of said duct being positioned to be closed by said piston during movement of said plunger in said opposite direction, the other end of said duct communicating with said space, and said injector body has a drain bore therein having one end opening into said plunger bore in constant registry with said space and the other end adapted to be connected to a drain, said duct, said space, and said drain bore comprising a drain passage in said injector body pErmitting fuel to be freely drawn into or expelled from between said plunger and said piston when said one end of said duct is open.
Claim 2
Dependent Claim
411 words
An injector for injecting fuel into a cylinder of an internal combustion engine, comprising an injector body having a fuel injection chamber provided with an opening adapted to communicate with said cylinder, a valve member in said body and normally closing said opening, said valve member being movable to a position permitting fuel flow from said fuel injection chamber through said opening when the pressure of the fuel in said fuel injection chamber reaches a predetermined value, fluid displacement means movably mounted in said injector body and defining a receiving chamber therein, said injector body also having a connecting passage connecting said receiving chamber with said fuel injection chamber and a supply passage adapted to connect said receiving chamber with a source of fuel under variable pressure for supplying varying quantities of fuel to said receiving chamber, the volume of said receiving chamber being determined by the extent of movement of said fluid displacement means and limited to a predetermined maximum when said fluid displacement means is moved fully in one direction, and said fluid displacement means being movable in the opposite direction to reduce the volume of said receiving chamber and increase the pressure therein and thereby move said valve member to an open position whereby a quantity of fuel from said fuel injection chamber is injected through said opening into said cylinder, said injector body having a bore therein, said fluid displacement means comprising a piston and a reciprocable plunger in said bore, and said plunger being operable to move said piston in said opposite direction, said receiving chamber being located between said piston and one end of said bore, said plunger having a reduced diameter portion defining a space in said bore and a duct therein having one end communicating with said plunger bore between said plunger and said piston, said one end of said duct being positioned to be closed by said piston during movement of said plunger in said opposite direction, the other end of said duct communicating with said space, and said injector body has a drain bore therein having one end opening into said plunger bore in constant registry with said space and the other end adapted to be connected to a drain, said duct, said space, and said drain bore comprising a drain passage in said injector body pErmitting fuel to be freely drawn into or expelled from between said plunger and said piston when said one end of said duct is open.
Claim 3
Dependent Claim
272 words
An injector for injecting fuel into a cylinder of an internal combustion engine, comprising an injector body having a chamber formed therein and a passage for connecting said chamber with said cylinder, a valve member movably mounted in said passage and normally being in a first position where it closes said opening, said valve member being movable by fuel pressure thereon to a second position where it opens said opening to enable injection of fuel, a plunger and a piston movably mounted in said chamber, said plunger being adapted to be driven in an injection stroke and in a return stroke, said body further including first passage means therein adapted to be connected with a source of fuel under variable pressure and second passage means therein adapted to be connected with a low pressure zone, said first passage means communicating with said chamber on one side of said piston and said second passage means communicating with said chamber on the other side of said piston, said second passage means being open during at least a portion of said return stroke and being closed by said piston during at least a portion of said injection stroke, said plunger exerting pressure on fuel in said chamber when said second passage means is closed during said portion of said injection stroke and thus moving said valve member to said second position, and spill passage means connected to said chamber and located to be opend by movement of said plunger to terminate injection, said plunger and said piston being axially aligned in said chamber, and said second passage means including a hole formed in said plunger.
Claim 4
Dependent Claim
272 words
An injector for injecting fuel into a cylinder of an internal combustion engine, comprising an injector body having a chamber formed therein and a passage for connecting said chamber with said cylinder, a valve member movably mounted in said passage and normally being in a first position where it closes said opening, said valve member being movable by fuel pressure thereon to a second position where it opens said opening to enable injection of fuel, a plunger and a piston movably mounted in said chamber, said plunger being adapted to be driven in an injection stroke and in a return stroke, said body further including first passage means therein adapted to be connected with a source of fuel under variable pressure and second passage means therein adapted to be connected with a low pressure zone, said first passage means communicating with said chamber on one side of said piston and said second passage means communicating with said chamber on the other side of said piston, said second passage means being open during at least a portion of said return stroke and being closed by said piston during at least a portion of said injection stroke, said plunger exerting pressure on fuel in said chamber when said second passage means is closed during said portion of said injection stroke and thus moving said valve member to said second position, and spill passage means connected to said chamber and located to be opend by movement of said plunger to terminate injection, said plunger and said piston being axially aligned in said chamber, and said second passage means including a hole formed in said plunger.
Claim 5
Dependent Claim
278 words
An injector for injecting fuel into a cylinder of an internal combustion engine, comprising an injector body having a chamber formed therein and a passage for connecting said chamber with said cylinder, a valve member movably mounted in said passage and normally being in a first position where it closes said opening, said valve member being movable by fuel pressure thereon to a second position where it opens said opening to enable injection of fuel, a plunger and a piston movably mounted in said chamber, said plunger being adapted to be driven in an injection stroke and in a return stroke, said body further including first passage means therein adapted to be connected with a source of fuel under variable pressure and second passage means therein adapted to be connected with a low pressure zone, said first passage means communicating with said chamber on one side of said piston and said second passage means communicating with said chamber on the other side of said piston, said second passage means being open during at least a portion of said return stroke and being closed by said piston during at least a portion of said injection stroke, said plunger exerting pressure on fuel in said chamber when said second passage means is closed during said portion of said injection stroke and thus moving said valve member to said second position, and spill passage means connected to said chamber and located to be opened by movement of said plunger to terminate injection, the portion of said chamber containing said valve member being connected to the remainder of said chamber by a connecting passage, said connecting passage opening into said one side.
Claim 6
Dependent Claim
278 words
An injector for injecting fuel into a cylinder of an internal combustion engine, comprising an injector body having a chamber formed therein and a passage for connecting said chamber with said cylinder, a valve member movably mounted in said passage and normally being in a first position where it closes said opening, said valve member being movable by fuel pressure thereon to a second position where it opens said opening to enable injection of fuel, a plunger and a piston movably mounted in said chamber, said plunger being adapted to be driven in an injection stroke and in a return stroke, said body further including first passage means therein adapted to be connected with a source of fuel under variable pressure and second passage means therein adapted to be connected with a low pressure zone, said first passage means communicating with said chamber on one side of said piston and said second passage means communicating with said chamber on the other side of said piston, said second passage means being open during at least a portion of said return stroke and being closed by said piston during at least a portion of said injection stroke, said plunger exerting pressure on fuel in said chamber when said second passage means is closed during said portion of said injection stroke and thus moving said valve member to said second position, and spill passage means connected to said chamber and located to be opened by movement of said plunger to terminate injection, the portion of said chamber containing said valve member being connected to the remainder of said chamber by a connecting passage, said connecting passage opening into said one side.
Claim 7
Dependent Claim
364 words
A fuel injector comprising an injector body having a fuel receiving chamber formed therein, a plunger reciprocably mounted in said body and cyclically movable in an injection stroke and in a return stroke, said body having a fuel supply passage therein adapted to be connected to receive fuel from a variable pressure fuel supply and a spill passage therein adapted to be connected to a low pressure zone, said plunger when moving in one portion of its cycle of movement opening said supply passage for flow of fuel from said supply into said chamber and when in another portion of said cycle opening said spilL passage for flow of fuel out of said chamber to said zone, said body further having spray holes formed therein and an injection passage connecting said chamber with said spray holes, a fuel pressure actuated valve in said injection passage, said valve being opened by fuel pressure in said chamber and in said injection passage during the time that said supply passage and said spill passage are closed by said plunger during said injection stroke, said pressure in said chamber being caused by movement of said plunger in said injection stroke and the amount of fuel entering said injection chamber being a function of the pressure of the fuel received from said fuel supply down to substantially zero fuel supply pressure, and further including a member movably mounted in said body and having one side thereof forming a wall of said receiving chamber, said body further having passage means therein adapted to connect a low pressure zone to the side of said member which is opposite said one side, whereby said member is movable to vary the size of said chamber as fuel flows into said chamber from said supply and said passage to said zone prevents suction from occurring while said plunger is moving in said return stroke, the flow of fuel from said supply passage and into said chamber being controlled only by the movement of said plunger, whereby the quantity of fuel flowing into said chamber is determined by the pressure of the fuel from said supply and may be varied down to substantially zero quantity.
Claim 8
Dependent Claim
364 words
A fuel injector comprising an injector body having a fuel receiving chamber formed therein, a plunger reciprocably mounted in said body and cyclically movable in an injection stroke and in a return stroke, said body having a fuel supply passage therein adapted to be connected to receive fuel from a variable pressure fuel supply and a spill passage therein adapted to be connected to a low pressure zone, said plunger when moving in one portion of its cycle of movement opening said supply passage for flow of fuel from said supply into said chamber and when in another portion of said cycle opening said spilL passage for flow of fuel out of said chamber to said zone, said body further having spray holes formed therein and an injection passage connecting said chamber with said spray holes, a fuel pressure actuated valve in said injection passage, said valve being opened by fuel pressure in said chamber and in said injection passage during the time that said supply passage and said spill passage are closed by said plunger during said injection stroke, said pressure in said chamber being caused by movement of said plunger in said injection stroke and the amount of fuel entering said injection chamber being a function of the pressure of the fuel received from said fuel supply down to substantially zero fuel supply pressure, and further including a member movably mounted in said body and having one side thereof forming a wall of said receiving chamber, said body further having passage means therein adapted to connect a low pressure zone to the side of said member which is opposite said one side, whereby said member is movable to vary the size of said chamber as fuel flows into said chamber from said supply and said passage to said zone prevents suction from occurring while said plunger is moving in said return stroke, the flow of fuel from said supply passage and into said chamber being controlled only by the movement of said plunger, whereby the quantity of fuel flowing into said chamber is determined by the pressure of the fuel from said supply and may be varied down to substantially zero quantity.
Claim 9
Dependent Claim
331 words
A fuel injector comprising an injector body having a fuel receiving chamber formed therein, a plunger reciprocably mounted in said body and cyclically movable in an injection stroke and a return stroke, said body having a fuel supply passage therein adapted to be connected to receive fuel from a variable pressure fuel supply and a spill passage therein adapted to be connected to a low pressure zone, said plunger when moving in one portion of its cycle of movement opening said supply passage for flow of fuel from said supply into said chamber and when in another portion of said cycle opening said spill passage for flow of fuel out of said chamber to said zone, said body further having spray holes formed therein and an injection passage connecting said chamber with said spray holes, a fuel pressure actuated valve in said injection passage, said valve being opened by fuel pressure in said chamber and in said injection passage during the time that said supply passage and said spill passage are closed by said plunger during said injection stroke, said pressure in said chamber being caused by movement of said plunger in said injection stroke, and a member movably mounted in said body and having one side thereof forming a wall of said receiving chamber, said body further having passage means therein adapted to connect a low pressure zone to the side of said member which is opposite said one side, whereby said member is movable to vary the size of said chamber as fuel flows into said chamber from said supply and said passage to said sump prevents suction from occurring while said plunger is moving in said return stroke, the flow of fuel from said supply passage and into said chamber being controlled only by the movement of said plunger, whereby the quantity of fuel flowing into said chamber is determined by the pressure of the fuel from said supply and may be varied down to substantially zero quantity.
Claim 10
Dependent Claim
331 words
A fuel injector comprising an injector body having a fuel receiving chamber formed therein, a plunger reciprocably mounted in said body and cyclically movable in an injection stroke and a return stroke, said body having a fuel supply passage therein adapted to be connected to receive fuel from a variable pressure fuel supply and a spill passage therein adapted to be connected to a low pressure zone, said plunger when moving in one portion of its cycle of movement opening said supply passage for flow of fuel from said supply into said chamber and when in another portion of said cycle opening said spill passage for flow of fuel out of said chamber to said zone, said body further having spray holes formed therein and an injection passage connecting said chamber with said spray holes, a fuel pressure actuated valve in said injection passage, said valve being opened by fuel pressure in said chamber and in said injection passage during the time that said supply passage and said spill passage are closed by said plunger during said injection stroke, said pressure in said chamber being caused by movement of said plunger in said injection stroke, and a member movably mounted in said body and having one side thereof forming a wall of said receiving chamber, said body further having passage means therein adapted to connect a low pressure zone to the side of said member which is opposite said one side, whereby said member is movable to vary the size of said chamber as fuel flows into said chamber from said supply and said passage to said sump prevents suction from occurring while said plunger is moving in said return stroke, the flow of fuel from said supply passage and into said chamber being controlled only by the movement of said plunger, whereby the quantity of fuel flowing into said chamber is determined by the pressure of the fuel from said supply and may be varied down to substantially zero quantity.
Claim 11
Dependent Claim
20 words
A fuel injector as in claim 5, and further including fuel flow restricing orifice means mounted in said supply passage.
Claim 12
Dependent Claim
297 words
An engine injector for operation in a fuel system including means for supplying fuel to said injector and for controlling the fuel pressure in order to control the quantity of fuel injected by the injector in each cycle of operation, said injector comprising an injector body having chamber means formed in said body and connected to receive fuel through a normally open passageway from said pressure controlling means, the quantity of the fuel flowing into said chambeR means being a function of the pressure of the fuel, spray holes formed in said body for connecting said chamber means with a combustion chamber of the engine, a normally closed valve positioned to control the flow of fuel out of said chamber means through said holes, said valve being openable to enable fuel flow only when the fuel pressure in said chamber means is above a predetermined value, fluid displacement means mounted in said body and reciprocably movable in an injection stroke and in a retraction stroke, said displacement means during said injection stroke trapping fuel in said chamber means and exerting pressure on said trapped fuel to above said predetermined value and thereby opening said valve, spill port means connected to said chamber means and located to be opened by movement of said displacement means at the end of said injection stroke, said opening of said spill port means venting a portion of said trapped fuel from said chamber means and resulting in prompt closure of said valve, and said body further having passage means therein adapted to be connected to a low pressure fuel zone, said passage means being open during at least a portion of said retraction stroke to permit low pressure fuel to flow from said zone into said chamber means during said retraction stroke.
Claim 13
Dependent Claim
297 words
An engine injector for operation in a fuel system including means for supplying fuel to said injector and for controlling the fuel pressure in order to control the quantity of fuel injected by the injector in each cycle of operation, said injector comprising an injector body having chamber means formed in said body and connected to receive fuel through a normally open passageway from said pressure controlling means, the quantity of the fuel flowing into said chambeR means being a function of the pressure of the fuel, spray holes formed in said body for connecting said chamber means with a combustion chamber of the engine, a normally closed valve positioned to control the flow of fuel out of said chamber means through said holes, said valve being openable to enable fuel flow only when the fuel pressure in said chamber means is above a predetermined value, fluid displacement means mounted in said body and reciprocably movable in an injection stroke and in a retraction stroke, said displacement means during said injection stroke trapping fuel in said chamber means and exerting pressure on said trapped fuel to above said predetermined value and thereby opening said valve, spill port means connected to said chamber means and located to be opened by movement of said displacement means at the end of said injection stroke, said opening of said spill port means venting a portion of said trapped fuel from said chamber means and resulting in prompt closure of said valve, and said body further having passage means therein adapted to be connected to a low pressure fuel zone, said passage means being open during at least a portion of said retraction stroke to permit low pressure fuel to flow from said zone into said chamber means during said retraction stroke.
Claim 14
Dependent Claim
19 words
An injector as in claim 7, and further including means in said normally open passageway forming a balance orifice.
Claim 15
Dependent Claim
23 words
An injector as in claim 7, wherein said spill port means is connected to vent trapped fuel to said low pressure fuel zone.
Claim 16
Dependent Claim
22 words
An injector as in claim 7, wherein said spill port means is connected to vent trapped fuel to said normally open passageway.
Claim 17
Dependent Claim
63 words
An injector as in claim 7, wherein said normally closed valve means includes a valve seat, a valve member, and a spring urging said valve member toward said valve seat, one end of said valve member being exposed to said trapped fuel pressure in said chamber means, and the other end of said valve member being exposed to said low pressure fuel zone.
Claim 18
Dependent Claim
25 words
An injector as in claim 11, wherein said plunger engages said spring and varies the force exerted by said spring with movement of said plunger.
Claim 19
Dependent Claim
24 words
An injector as in claim 7, wherein said displacement means comprises a plunger and a piston, said piston being movable in said chamber means.
Claim 20
Dependent Claim
18 words
An injector as in claim 13, wherein said plunger and said piston are movable along a single axis.
Claim 21
Dependent Claim
36 words
An injector as in claim 13, wherein said plunger is movable along a first axis and said piston is movable along a second axis, said first and second axes being laterally displaced in said injector body.
Claim 22
Dependent Claim
49 words
An injector as in claim 13, wherein the pressure of said trapped fuel in said chamber means urges said piston in a first direction, and further including a metering spring connected to said piston and urging said piston in the opposite direction against said pressure of said trapped fuel.
Claim 23
Dependent Claim
14 words
An injector as in claim 16, wherein said metering spring is a linear spring.
Claim 24
Dependent Claim
33 words
An injector as in claim 13, wherein said piston is movable to close said passage means during said injection stroke, said piston being moved by fuel pressure caused by movement of said plunger.
Claim 25
Dependent Claim
37 words
An injector as in claim 18, wherein a portion of said passage means is formed in said plunger, and said plunger and said piston engage to close said portion of said passage means during said injection stroke.
Claim 26
Dependent Claim
48 words
An injector as in claim 13, wherein said normally open passageway, said spill port and said spray holes are all connected to said chamber means on one side of said piston, and said passage means is connected to said chamber means on the other side of said piston.
Claim 27
Dependent Claim
21 words
An injector as in claim 20, wherein said one side of said piston comprises its side which is adjacent said plunger.
Claim 28
Dependent Claim
22 words
An injector as in claim 20, wherein said one side of said piston comprises its side which is away from said plunger.
References Cited (Backward Citations)
US2378165A
Cited
US2430801A
Cited
US2424943A
Cited
US2474419A
Cited
US2727498A
Cited
US3003421A
Cited
US2928352A
Cited
US3016835A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |