1. A two-step rocker arm assembly comprising:
an arm member;
a first roller assembly rotatably mounted with respect to said arm member and defining a generally curved opening;
a shaft member;
a second roller assembly rotatably supported by said shaft member;
wherein said shaft member extends at least partially into said generally curved opening, said shaft member being selectively translatable within said generally curved opening to guide said second roller assembly with respect to said arm member; and
a coupling lever mounted with respect to said shaft member and operable to selectively retain said shaft member with respect to said arm member for unitary movement therewith.
2. The two-step rocker arm assembly of claim 1, further comprising:
a first spring lever pivotably mounted with respect to said arm member and engaged with at least one of said shaft member and said second roller assembly; and
a first spring member disposed between said first spring lever and said arm member and operable to bias said shaft member with respect to said arm member.
3. The two-step rocker arm assembly of claim 1, further comprising a third roller assembly rotatably supported by said shaft member.
4. The two-step rocker arm assembly of claim 3, further comprising:
a second spring lever pivotably mounted with respect to said arm member and engaged with at least one of said shaft member and said third roller assembly; and
a second spring member disposed between said second spring lever and said arm member and operable to bias said shaft member with respect to said arm member.
5. The two-step rocker arm assembly of claim 1, wherein said first roller assembly includes:
an inner race;
an outer race coaxially disposed with respect to, and spaced from said inner race;
a plurality of roller elements disposed between said inner race and said outer race; and
wherein said inner race defines said generally curved opening.
6. The two-step rocker arm assembly of claim 1, further comprising a latch assembly operable to selectively engage said coupling lever to selectively retain said shaft member to said arm member for unitary movement therewith.
7. The two-step rocker arm assembly of claim 6, wherein said latch assembly includes a hydraulically actuated pin.
8. The two-step rocker arm assembly of claim 1, wherein said second roller assembly is a roller bearing.
9. The two-step rocker arm assembly of claim 3, wherein said third roller assembly is a roller bearing.
10. The two-step rocker arm assembly of claim 5, wherein said inner race is fixed with respect to said arm member.
11. A valvetrain comprising:
a camshaft having a low-lift cam and a high-lift cam;
a two-step rocker arm assembly including:
an arm member;
a first roller assembly rotatably mounted with respect to said arm member and defining a generally C-shaped opening;
a shaft member;
a second roller assembly rotatably supported by said shaft member;
wherein said shaft member extends at least partially into said generally C-shaped opening, said shaft member being selectively translatable within said generally C-shaped opening to guide said second roller assembly with respect to said arm member;
a coupling lever mounted with respect to said shaft member;
a selectively engageable latch assembly operable to selectively engage said coupling lever to selectively retain said shaft member with respect to said first arm member for unitary movement therewith;
wherein said low-lift cam is in selective engagement with said first roller assembly and said high lift cam is engaged with said second roller assembly;
wherein said hi-lift cam is configured to actuate said two-step rocker arm assembly when said latch assembly engages said coupling lever; and
wherein said low-lift cam is configured to actuate said two-step rocker arm assembly when said latch assembly disengages said coupling lever.
12. The valvetrain of claim 11, further comprising another high lift cam disposed on said camshaft and positioned such that said another high-lift cam and said high-lift cam are on opposite sides of said low-lift cam and wherein said two-step rocker arm assembly further includes a third roller assembly rotatably supported by said shaft member, wherein said another high-lift cam engages said third roller assembly.
13. The valvetrain of claim 12, wherein said two-step rocker assembly further includes:
a first spring lever pivotably mounted with respect to said first arm member and engaged with at least one of said shaft member and said second roller assembly; and
a first spring member disposed between said first spring lever and said arm member and operable to bias said shaft member with respect to said arm member;
a second spring lever pivotably mounted with respect to said arm member and engaged with at least one of said shaft member and said third roller assembly; and
a second spring member disposed between said second spring lever and said arm member and operable to bias said shaft member with respect to said arm member.
14. The valvetrain of claim 11, wherein said first roller assembly includes:
an inner race;
an outer race coaxially disposed with respect to, and spaced from said inner race;
a plurality of roller elements disposed between said inner race and said outer race; and
wherein said inner race defines said generally C-shaped opening.
15. The valvetrain of claim 11, further comprising:
a poppet valve; and
wherein said arm member includes a pad configured to engage said poppet valve.
16. The valvetrain of claim 12, wherein at least one of said second roller assembly and said third roller assembly is a roller bearing.
17. A two-step rocker arm assembly for use with an internal combustion engine, the two-step rocker arm comprising:
an arm member;
a first roller assembly rotatably mounted with respect to said arm member and defining a generally C-shaped opening;
a shaft member;
second and third roller assemblies rotatably supported by said shaft member and disposed on opposite sides of said arm member;
wherein said shaft member extends through said generally C-shaped opening, said shaft member being selectively translatable within said generally C-shaped opening to guide said second and third roller assemblies with respect to said arm member; and
a coupling lever mounted with respect to said shaft member and operable to selectively retain said shaft member with respect to said arm member for unitary movement therewith.
18. The two-step rocker arm assembly of claim 17, wherein said first roller assembly includes:
an inner race;
an outer race coaxially disposed with respect to, and spaced from said inner race;
a plurality of roller elements disposed between said inner race and said outer race; and
wherein said inner race defines said generally C-shaped opening.
19. The two-step rocker arm assembly of claim 17, further comprising:
at least one spring lever pivotably mounted with respect to said arm member and engaged with at least one of said shaft member and said second roller assembly; and
at least one spring member disposed between said at least one spring lever and said arm member and operable to bias said shaft member with respect to said arm member.
20. The two-step rocker arm assembly of claim 17, further comprising a latch assembly operable to selectively engage said coupling lever to selectively retain said shaft member to said arm member for unitary movement therewith.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A microfluidic device comprising a plurality of channels within said microfluidic device, a means to add and control one or more of the external stimuli of temperature, current, and magnetic fields to said microfluidic device, an effective amount of a liquid crystal in an electrolyte buffer applied to said microfluidic device wherein said liquid crystal has a viscosity which can be modulated by said external stimuli to control fluid flow through said plurality of channels.
2. The microfluidic device of claim 1 wherein said liquid crystals serve as a selective media in an electrophoresis separation.
3. The microfluidic device of claim 1 wherein said means to control current is an array of high voltage interdigitated electrodes capable of applying a series of current pathways on said microfluidic device.
4. The microfluidic device of claim 1 wherein said liquid crystals are an effective ratio of DMPC to DPHC.
5. The microfluidic device of claim 4 further comprising an effective amount of a lanthanide ion.
6. The microfluidic device of claim 4 further comprising an effective amount of 1,2-Distearoylsn-Glycero-3-Phosphoethanolamine-N-Methoxy(Polyethylen glycol)-2000.
7. The microfluidic device of claim 4 further comprising a lipid chelator.
8. The microfluidic device of claim 1 further comprising a pump.
9. The microfluidic device of claim 8 further comprising said means to control current, temperature, and magnetic fields applied at different intensities throughout said microfluidic device.
10. The microfluidic device of claim 9 wherein an effective amount of said selective addition of external stimuli creates a viscosity gradient within said microfluidic device to allow flow through a desired course.
11. The microfluidic device of claim 1 further comprising the addition of said current and said magnetic field across said channel walls.
12. A non-mechanical valve comprising a miniaturized separation device, a means to add and control one or more of the external stimuli of current, magnetic fields, and temperature within said miniaturized separation device, an effective amount of liquid crystals within said miniaturized separation device wherein said liquid crystals are exposed to said external stimuli to increase or decrease the viscosity of said liquid crystals and create an area of higher viscosity such that hydrodynamic or electro osmotic flow throughout said miniaturized separation device is diverted to areas with lower viscosity
13. The non-mechanical valve of claim 12 wherein said liquid crystals are an effective ratio of DMPC and DHPC.
14. The non-mechanical valve of claim 13 further comprising the addition of at least one additive chosen from 1,2-Distearoylsn-Glycero-3-Phosphoethanolamine-N-Methoxy(Polyethylen glycol)-2000, a lipid chelator, or a lanthanide ion.
15. The non-mechanical valve of claim 12 wherein an effective amount of said external stimuli are used in a series to modulate viscosity changes on the miniaturized separation device such that a gradient of hydrodynamic pressure is created.
16. The non-mechanical valve of claim 12 wherein said current and said magnetic field are perpendicular to each other.
17. The non-mechanical valve of claim 12 wherein said means to add and control one or more external stimuli are placed within said miniaturized separation device.
18. The non-mechanical valve of claim 12 wherein said current is provided by a platform of addressable electrodes and said temperature and said magnetic field are supplied externally.
19. A non-mechanical plug comprising microfluidic device further comprising a plurality of channels, a means to add and control one or more of the external stimuli of current, magnetic fields, and temperature in an effective amount within said microfluidic device, a pump, and an effective amount of liquid crystals wherein said external stimuli are added to selected channels to decrease viscosity within said channel and prevent fluid flow into thereby creating a plug in non-stimulated channels.
20. The non-mechanical plug of claim 20 wherein said change in viscosity can be used to anchor an antibody or a protein in said plugged channel.