US5682858A — Hydraulically-actuated fuel injector with pressur…

Claim 1

Independent Claim 158 words

A hydraulically actuated fuel injector comprising: an injector body having an actuation fluid cavity, a needle control chamber, a nozzle chamber and a nozzle outlet that opens to said nozzle chamber; hydraulic means, within said injector body, for pressurizing fuel in said nozzle chamber; a needle valve member positioned to reciprocate in said nozzle chamber between an opened position in which said nozzle outlet is open and a closed position in which said nozzle outlet is closed, said needle valve member including a closing hydraulic surface exposed to pressure in said needle control chamber; a needle control valve mounted within said injector body, and being movable between an off position in which said needle control chamber is opened to a source of high pressure fluid and an on position in which said needle control chamber is opened to a low pressure passage; and means, within said injector body, for venting post injection pressure from said actuation fluid cavity.

Claim 2

Dependent Claim 158 words

A hydraulically actuated fuel injector comprising: an injector body having an actuation fluid cavity, a needle control chamber, a nozzle chamber and a nozzle outlet that opens to said nozzle chamber; hydraulic means, within said injector body, for pressurizing fuel in said nozzle chamber; a needle valve member positioned to reciprocate in said nozzle chamber between an opened position in which said nozzle outlet is open and a closed position in which said nozzle outlet is closed, said needle valve member including a closing hydraulic surface exposed to pressure in said needle control chamber; a needle control valve mounted within said injector body, and being movable between an off position in which said needle control chamber is opened to a source of high pressure fluid and an on position in which said needle control chamber is opened to a low pressure passage; and means, within said injector body, for venting post injection pressure from said actuation fluid cavity.

Claim 3

Dependent Claim 70 words

The fuel injector of claim 1, wherein said means for venting post injection pressure includes said injector body having a pressure relief passage extending between said actuation fluid cavity and a low pressure actuation fluid drain; and a relief valve mounted within said injector body and having a first position in which said pressure relief passage is closed and a second position in which said pressure relief passage is open.

Claim 4

Dependent Claim 28 words

The fuel injector of claim 2, wherein said relief valve being hydraulically biased toward said second position when pressure in said actuation fluid cavity exceeds a threshold pressure.

Claim 5

Dependent Claim 29 words

The fuel injector of claim 2, wherein said relief valve includes a relief ball; and a portion of said pressure relief passage being a seat for said relief ball.

Claim 6

Dependent Claim 55 words

The fuel injector of claim 4 wherein said relief valve further includes a relief pin with an end hydraulic surface exposed to pressure in said actuation fluid inlet and an other end capable of contacting said relief ball; and said relief ball includes a second hydraulic surface exposed to pressure in said actuation fluid cavity.

Claim 7

Dependent Claim 38 words

The fuel injector of claim 2 wherein said injector body includes a piston bore; said actuation fluid cavity including a portion of said piston bore; and said pressure relief passage opens into said portion of said piston bore.

Claim 8

Dependent Claim 63 words

The fuel injector of claim 6 wherein said needle valve member includes an opening hydraulic surface exposed to pressure in said nozzle chamber; said closing hydraulic surface and said opening hydraulic surface are sized and arranged such that said needle valve member is hydraulically biased toward said closed position when said needle control chamber is opened to said source of high pressure fluid.

Claim 9

Dependent Claim 54 words

The fuel injector of claim 5 wherein said hydraulic means for pressurizing fuel includes a spool valve member; and said one end of said relief pin is in contact with said spool valve member when said spool valve member is in a position that opens said actuation fluid cavity to an actuation fluid inlet.

Claim 10

Dependent Claim 72 words

The fuel injector of claim 2 wherein said hydraulic means for pressurizing fuel includes an actuation fluid control valve and said injector body having an actuation fluid inlet; and said actuation fluid control valve having a pin attached to a solenoid, and including said injector body having a low pressure seat and a high pressure seat, and further including a ball positioned between said low pressure seat and said high pressure seat.

Claim 11

Dependent Claim 107 words

The fuel injector of claim 9 wherein said actuation fluid control valve further includes a spool valve member movable between a first position and a second position; said spool valve member opens said actuation fluid cavity to said actuation fluid inlet and closes said actuation fluid drain to said actuation fluid cavity when in said first position; said spool valve member closes said actuation fluid cavity to said actuation fluid inlet and opens said actuation fluid drain to said actuation fluid cavity when in said second position; and means, including a spring positioned in said injector body, for biasing said spool valve member toward said second position.

Claim 12

Dependent Claim 102 words

The fuel injector of claim 10 wherein said injector body includes an actuation fluid control passage; said spool valve member having an end hydraulic surface exposed to pressure in said actuation fluid control passage, said high pressure seat separating said actuation fluid control passage and said actuation fluid inlet, and said low pressure seat separating said actuation fluid control passage and a low pressure drain passage; and said spool valve member being hydraulically biased toward said first position when said ball is seated in said high pressure seat and said actuation fluid control passage is open to said low pressure drain passage.

Claim 13

Dependent Claim 130 words

A hydraulically actuated fuel injector comprising: an injector body having a nozzle chamber, a nozzle outlet, an actuation fluid inlet, an actuation fluid drain, an actuation fluid cavity and a pressure relief passage extending between said actuation fluid cavity and said actuation fluid drain; hydraulic means, including an actuation fluid control valve mounted within said injector body, for pressurizing fuel in said nozzle chamber; a needle valve member mounted to reciprocate in said nozzle chamber between an open position in which said nozzle outlet is open and a closed position in which said nozzle outlet is closed; a relief valve mounted within said injector body and having a first position in which said pressure relief passage is closed and a second position in which said pressure relief passage is open.

Claim 14

Dependent Claim 130 words

A hydraulically actuated fuel injector comprising: an injector body having a nozzle chamber, a nozzle outlet, an actuation fluid inlet, an actuation fluid drain, an actuation fluid cavity and a pressure relief passage extending between said actuation fluid cavity and said actuation fluid drain; hydraulic means, including an actuation fluid control valve mounted within said injector body, for pressurizing fuel in said nozzle chamber; a needle valve member mounted to reciprocate in said nozzle chamber between an open position in which said nozzle outlet is open and a closed position in which said nozzle outlet is closed; a relief valve mounted within said injector body and having a first position in which said pressure relief passage is closed and a second position in which said pressure relief passage is open.

Claim 15

Dependent Claim 50 words

The fuel injector of claim 12 wherein said actuation fluid control valve having a pin attached to a solenoid, and including said injector body having a low pressure seat and a high pressure seat, and further including a ball positioned between said low pressure seat and said high pressure seat.

Claim 16

Dependent Claim 107 words

The fuel injector of claim 13 wherein said actuation fluid control valve further includes a spool valve member movable between a first position and a second position; said spool valve member opens said actuation fluid cavity to said actuation fluid inlet and closes said actuation fluid drain to said actuation fluid cavity when in said first position; said spool valve member closes said actuation fluid cavity to said actuation fluid inlet and opens said actuation fluid drain to said actuation fluid cavity when in said second position; and means, including a spring positioned in said injector body, for biasing said spool valve member toward said second position.

Claim 17

Dependent Claim 108 words

The fuel injector of claim 14 wherein said injector body includes a actuation fluid control passage; said actuation fluid control valve includes said spool valve member having an end hydraulic surface exposed to pressure in said actuation fluid control passage, said high pressure seat separating said actuation fluid control passage and said actuation fluid inlet, and said low pressure seat separating said actuation fluid control passage and a low pressure drain passage; and said spool valve member being hydraulically biased toward said first position when said ball is seated in said high pressure seat and said actuation fluid control passage is open to said low pressure drain passage.

Claim 18

Dependent Claim 108 words

The fuel injector of claim 12, wherein said actuation fluid control valve includes a spool valve member moveable between a first position and a second position; said spool valve member opens said actuation fluid cavity to said actuation fluid inlet and closes said actuation fluid drain to said actuation fluid cavity when in said first position; said spool valve member closes said actuation fluid cavity to said actuation fluid inlet and opens said actuation fluid drain to said actuation fluid cavity when in said second position; and said relief valve being hydraulically biased toward said second position when pressure in said actuation fluid cavity exceeds a threshold pressure.

Claim 19

Dependent Claim 41 words

The fuel injector of claim 16, wherein said relief valve includes a relief ball, a relief pin with one end capable of contacting said relief ball, and a portion of said pressure relief passage being a seat for said relief ball.

Claim 20

Dependent Claim 49 words

The fuel injector of claim 17 wherein said relief valve further includes said relief pin having an other end with a first hydraulic surface exposed to pressure in said actuation fluid inlet; and said relief ball includes a second hydraulic surface exposed to pressure in said actuation fluid cavity.

Claim 21

Dependent Claim 32 words

The fuel injector of claim 18 wherein said other end of said relief pin is in contact with said spool valve member when said spool valve member is in said first position.

Claim 22

Dependent Claim 38 words

The fuel injector of claim 12 wherein said injector body includes a piston bore; said actuation fluid cavity including a portion of said piston bore; and said pressure relief passage opens into said portion of said piston bore.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-11-03	2001-05-05	2001-11-04	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-11-03	2005-05-05	2005-11-04	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-11-03	2009-05-05	2009-11-04	$7700.00	Window Closed / Lapsed

Hydraulically-actuated fuel injector with pressure spike relief valve

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