1. An exhaust valve assembly for a two-stroke internal combustion engine comprising:
a valve actuator movable between a first position, a second position and a third position, the second position being intermediate the first and third positions;
a two-part valve having a first valve part and a second valve part, the first valve part being operatively connected to the valve actuator,
the first valve part being in a fourth position when the valve actuator is in the first position,
the first valve part being in a fifth position when the valve actuator is in the second position,
the first valve part being in a sixth position when the valve actuator is in the third position,
the fifth position being intermediate the fourth position and the sixth position,
the second valve part being in a seventh position when the valve actuator is in any one of the first and second position,
the second valve part being in an eighth position when the valve actuator is in the third position; and
at least one auxiliary valve operatively connected to the second valve part,
the at least one auxiliary valve being in a ninth position when the second valve part is in the seventh position, and
the at least one auxiliary valve being in a tenth position when the second valve part is in the eighth position.
2. The exhaust valve assembly of claim 1, wherein a distance traveled by the at least one auxiliary valve between the ninth and tenth positions is greater than a distance traveled by the first valve part between the fourth and sixth positions.
3. The exhaust valve assembly of claim 1, wherein the fourth, seventh and ninth positions are flow restricting positions of the first valve part, the second valve part and the at least one auxiliary valve respectively;
wherein the sixth, eighth and tenth positions are full flow positions of the first valve part, the second valve part and the at least one auxiliary valve respectively; and
wherein the fifth position is an intermediate position of the first valve part.
4. The exhaust valve assembly of claim 1, further comprising a lever pivotally connecting the at least one auxiliary valve to the second valve part.
5. The exhaust valve assembly of claim 4, wherein the lever comprises:
at least one arm having a first end and a second end;
at least one first shaft connected to the first end of the at least one arm, the at least one first shaft being pivotally connected to the at least one auxiliary valve;
at least one second shaft connected between the first and second ends of the at least one arm, the at least one second shaft being pivotally connected to the second valve part; and
at least one third shaft connected to the second end of the at least one arm, the at least one third shaft abutting a portion of the valve actuator.
6. The exhaust valve assembly of claim 5, wherein the at least one third shaft abuts at least one post extending from the valve actuator.
7. The exhaust valve assembly of claim 5, wherein the at least one arm is V-shaped; and
wherein the at least one second shaft is connected at the corner of the V-shaped arm.
8. The exhaust valve assembly of claim 5, wherein the second valve part has at least one pair of fingers; and
wherein the at least one second shaft is received between the at least one pair of fingers.
9. The exhaust valve assembly of claim 8, wherein when the first valve part moves from the fifth position to the sixth position, the first valve part abuts at least one of the fingers to move the second valve part from the seventh position to the eight position and the at least one auxiliary valve from the ninth position to the tenth position.
10. The exhaust valve assembly of claim 1, wherein when the first valve part moves from the fifth position to the sixth position, the first valve part abuts a portion of the second valve part to move the second valve part from the seventh position to the eight position and the at least one auxiliary valve from the ninth position to the tenth position.
11. The exhaust valve assembly of claim 1, further comprising at least one spring for biasing the second valve part toward the seventh position.
12. The exhaust valve assembly of claim 1, wherein the at least one auxiliary valve is two auxiliary valves; and
wherein the first valve part and the second valve part are disposed between the two auxiliary valves.
13. The exhaust valve assembly of claim 1, wherein the valve actuator is biased toward the second position.
14. The exhaust valve assembly of claim 1, wherein the valve actuator is a pneumatic actuator.
15. An internal combustion engine comprising:
a crankcase;
a crankshaft disposed in the crankcase;
a cylinder block connected to the crankcase, the cylinder block having a main exhaust passage and at least one auxiliary exhaust passage;
a cylinder disposed in the cylinder block;
a piston movably disposed within the cylinder and being operatively connected to the crankshaft; and
the valve assembly of claim 1 connected to the cylinder block;
wherein when the first valve part is in the fourth position, the first valve part extends a first distance in the main exhaust passage;
wherein when the first valve part is in the fifth position, the first valve part extends a second distance in the main exhaust passage, the second distance being less than the first distance;
wherein when the first valve part is in the sixth position, the first valve part is withdrawn from the main exhaust passage;
wherein when the second valve part is in the seventh position, the second valve part extends a third distance in the main exhaust passage;
wherein when the second valve part is in the eighth position, the second valve part is withdrawn from the main exhaust passage;
wherein when the at least one auxiliary valve is in the ninth position, the at least one auxiliary valve extends a fourth distance in the at least one auxiliary exhaust passage; and
wherein when the at least one auxiliary valve is in the tenth position, the at least one auxiliary valve is withdrawn from the at least one auxiliary exhaust passage.
16. The engine of claim 15, wherein the fourth distance is greater than the second and third distances.
17. A method of operating an exhaust valve assembly of a two-stroke internal combustion engine, the valve assembly including: a valve actuator, a two-part valve having a first valve part operatively connected to the valve actuator and a second valve part, and at least one auxiliary valve operatively connected to the two-part valve, the method comprising:
moving the valve actuator between a first position, a second position and a third position, the second position being intermediate the first and third positions;
moving the first valve part to a fourth position when the valve actuator is moved to the first position;
moving the first valve part to a fifth position when the valve actuator is moved to the second position;
moving the first valve part to a sixth position when the valve actuator is moved to the third position, the fifth position being intermediate the fourth position and the sixth position;
moving the second valve part to a seventh position when the valve actuator is moved to any one of the first and second position;
moving the second valve part to an eighth position when the valve actuator is moved to the third position;
moving the at least one auxiliary valve to a ninth position when the second valve part is moved to the seventh position; and
moving the at least one auxiliary valve to a tenth position when the second valve part is moved to the eighth position.
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. An implantable device comprising:
a thread comprising uncrosslinked hyaluronic acid or salts, hydrates or solvates thereof and crosslinked hyaluronic acid or salts, hydrates or solvates thereof.
2. The device of claim 1 wherein the crosslinked hyaluronic acid is crosslinked with a crosslinker selected from the group consisting of butanediol diglycidyl ether (BDDE), divinyl sulfone (DVS) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC).
3. The device of claim 1 wherein the crosslinked hyaluronic acid is crosslinked with butanediol diglycidyl ether (BDDE).
4. The device of claim 1 wherein the thread further comprises a therapeutic agent.
5. The device of claim 4 wherein the therapeutic agent is lidocaine.
6. A method of treating a wrinkle in a subject comprising:
implanting a hydratable thread into the dermis of the subject wherein the thread comprises uncrosslinked hyaluronic acid or salts, hydrates or solvates thereof and crosslinked hyaluronic acid or salts, hydrates or solvates thereof.
7. The method of claim 6 wherein the crosslinked hyaluronic acid is crosslinked with a crosslinker selected from the group consisting of butanediol diglycidyl ether (BDDE), divinyl sulfone (DVS) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC).
8. The method of claim 6 wherein the crosslinked hyaluronic acid is crosslinked with butanediol diglycidyl ether (BDDE).
9. The method of claim 6 further comprising implanting the thread using a needle attached to the thread.
10. The method of claim 9 wherein the implanting comprises
inserting a distal end of the needle through the skin surface of the subject adjacent to the wrinkle;
traversing the dermis of the subject under the wrinkle with the needle;
forcing the needle through the skin surface of the subject; and
cutting the thread from the needle at the skin surface of the subject.
11. A method of making an implantable device for treating wrinkles in skin, the method comprising:
mixing hyaluronic acid or salts, hydrates or solvates thereof with water or a buffer;
causing at least some of the hyaluronic acid or salts, hydrates or solvates thereof to become crosslinked with a crosslinker, to form a gel containing crosslinked hyaluronic acid;
extruding the gel into a thread;
drying the extruded thread to form a dried thread useful for treating wrinkles in skin.
12. The method of claim 11, further comprising mixing a therapeutic agent with the hyaluronic acid.
13. The method of claim 11 wherein the therapeutic agent is lidocaine.
14. The method of claim 11 further comprising hydrating the dried thread.
15. The method of claim 11 wherein the crosslinker is selected from the group consisting of butanediol diglycidyl ether (BDDE), divinyl sulfone (DVS) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC).
16. The method of claim 6 wherein the crosslinker is butanediol diglycidyl ether (BDDE).