1. Valve arrangement for controlling a fluid consumer, which valve arrangement is arranged for selectively connecting a source of fluid pressure to the consumer in order to actuate the consumer in a predetermined direction, the valve arrangement comprising:
a pressure controlled valve comprising a first valve port connected to the source of fluid pressure, a second valve port connected to a first chamber of the consumer, a valve cone slidably movable in a cavity in a valve body between a first position in which a connection between the first and second valve ports is closed by a first side of the valve cone, and a second position in which the connection between the first and second valve ports is open, said cone being urged to its closed position by fluid pressure acting on an opposite second side of the valve cone which second side forms a space with the valve body, means for passing fluid under pressure through the valve cone from the first and second valve ports to said space through passages each containing a non-return valve, and controllable valve means comprising a first pilot valve in a conduit connecting said space with the first valve port and a second pilot valve in a conduit connecting said space with the second valve port, which controllable valve means prevents the valve cone from opening if the pressure in one of the first and second valve ports intended to be an input port is lower than the pressure in the other of the first and second valve ports intended to be an output port.
2. Valve arrangement according to claim 1, wherein the first pilot valve is arranged to be actuated to allow a fluid flow from the second valve port to the first valve port, if the pressure in the second valve port exceeds that of the first valve port.
3. Valve arrangement according to claim 1, wherein the second pilot valve is arranged to be actuated to allow a fluid flow from the first valve port to the second valve port, if the pressure in the first valve port exceeds that of the second valve port.
4. Valve arrangement according to claim 1, further including a non-return valve in the conduit connecting the space with the first valve port and a non-return valve in the conduit connecting the space with the second valve port.
5. A fluid circuit comprising:
a controllable source of fluid pressure;
a fluid consumer having a first and a second chamber for fluid, wherein the consumer is arranged to be movable between a first and a second end position under the action of said fluid; and
a plurality of valve arrangements for selectively connecting the source of fluid pressure to the first or the second chamber of the consumer, in order to allow fluid to be supplied to or drained from the respective chamber,
wherein at least one of the plurality of valve arrangements for selectively connecting the source of fluid pressure to a first chamber of the consumer comprises a first valve port connected to the source of fluid pressure, a second valve port connected to the first chamber of the consumer, a valve cone slidably movable in a cavity in a valve body between a first position in which a connection between the first and second valve ports is closed by a first side of the valve cone, and a second position in which the connection between the first and second valve ports is open, said cone being urged to its closed position by fluid pressure acting on an opposite second side of the valve cone which second side forms a space with the valve body; means for passing fluid under pressure through the valve cone from the first and second valve ports to said space through passages each containing a non-return valve, and controllable valve means comprising a first pilot valve in a conduit connecting said space with the first valve port and a second pilot valve in a conduit connecting said space with the second valve port.
6. The fluid circuit according to claim 5, wherein the first pilot valve is arranged to be actuated to allow a fluid flow from the second valve port to the first valve port if the pressure in the first chamber exceeds that in a conduit connected to the source of fluid pressure.
7. The fluid circuit according to claim 5, wherein the source of fluid pressure comprises at least one reversible pump, wherein fluid pressure is recovered by operating said pump as a motor.
8. The fluid circuit according to claim 5, wherein the second pilot valve is arranged to be actuated to allow a fluid flow from the first valve port to the second valve port, if the pressure delivered by the source of fluid pressure exceeds that in the first chamber.
9. The fluid circuit according to claim 5, further including a non-return valve in the conduit connecting the space with the first valve port and a non-return valve in the conduit connecting the space with the second valve port.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A stent-graft delivery system comprising:
a pushrod comprising:
a lumen; and
a trigger aperture;
a stent-graft retainment system comprising:
a retainer structure; and
a retainer release trigger coupled to said retainer structure, said retainer release trigger comprising a trigger portion extending radially from said lumen through said trigger aperture; and
a sheath comprising a trigger trip surface.
2. The stent-graft delivery system of claim 1 wherein a longitudinal trigger trip distance exists between said trigger trip surface and said trigger portion prior to retraction of said sheath.
3. The stent-graft delivery system of claim 1 wherein said trigger portion extends radially outwards from said pushrod a first radial distance, and wherein a second radial distance exists between said pushrod and said sheath, said first radial distance being greater than said second radial distance.
4. The stent-graft delivery system of claim 3 wherein said trigger trip surface contacts said trigger portion during retraction of said sheath.
5. The stent-graft delivery system of claim 1 wherein said retainer release trigger further comprises a pull rod portion coupled to said trigger portion, said pull rod portion extending longitudinally through said lumen.
6. The stent-graft delivery system of claim 5 wherein said retainer release trigger further comprises a locking feature coupled to said trigger portion.
7. The stent-graft delivery system of claim 6 wherein said locking feature secures said trigger portion to said sheath during use of said stent-graft delivery system.
8. The stent-graft delivery system of claim 1 wherein said retainer structure comprises at least one hook extending from said lumen through at least one corresponding retainer aperture of said pushrod.
9. The stent-graft delivery system of claim 8 wherein a proximal end of said retainer structure is coupled to said retainer release trigger by a trigger wire coupler.
10. The stent-graft delivery system of claim 9 wherein said at least one hook extends distally from said trigger wire coupler through said at least one corresponding retainer aperture and curves to extend back in the proximal direction.
11. The stent-graft delivery system of claim 10 further comprising a stent-graft, wherein said at least one hook extends over a portion of said stent-graft.
12. The stent-graft delivery system of claim 11 wherein said portion of said stent-graft comprises a crown portion of said stent-graft.
13. The stent-graft delivery system of claim 11 wherein said at least one hook secures said portion of said stent-graft to said pushrod.
14. The stent-graft delivery system of claim 11 wherein said sheath radially constrains said stent-graft.
15. The stent-graft delivery system of claim 1 wherein said pushrod comprises at least one trench defined by at least one proximal annular surface, at least one distal annular surface, and at least one longitudinal ring surface of said pushrod, said retainer structure comprising at least one wire extending across said at least one trench.
16. The stent-graft delivery system of claim 15 wherein said at least one wire extends distally from said pushrod through a proximal retainer aperture in said at least one proximal annular surface, across said at least one trench, and back into said pushrod through a distal retainer aperture of said at least one distal annular surface.
17. The stent-graft delivery system of claim 15 wherein said at least one proximal annular surface, said at least one distal annular surface, said at least one longitudinal ring surface and said at least one wire define at least one pocket, said stent-graft delivery system further comprising a stent-graft comprising a portion located in said at least one pocket.
18. The stent-graft delivery system of claim 15 further comprising at least one swing pivotally attached to said at least one distal annular surface.
19. A stent-graft retainment system comprising:
a retainer structure; and
a retainer release trigger coupled to said retainer structure, said retainer release trigger comprising a pull rod portion coupled to a trigger portion.
20. The stent-graft retainment system of claim 19 further comprising a trigger wire coupler coupling said retainer structure to said retainer release trigger.
21. The stent-graft retainment system of claim 19 wherein said retainer release trigger further comprises a locking feature coupled to said trigger portion.
22. A method comprising:
mounting a stent-graft on a pushrod;
radially constraining said stent-graft within a sheath;
securing a crown portion of said stent-graft to said pushrod with a retainer structure of a stent-graft retainment system;
retracting said sheath to expose said crown portion of said stent-graft; and
further retracting said sheath to release said crown portion from said pushrod.
23. The method of claim 22 wherein said stent-graft self-expands upon said release of said crown portion from said pushrod.
24. The method of claim 22 wherein said further retracting comprises contacting a trigger portion of said stent-graft retainment system with a trigger trip surface of said sheath.
25. The method of claim 24 wherein said further retracting further comprises retracting said trigger portion to retract said retainer structure into said pushrod.
26. The method of claim 25 wherein said retainer structure is retracted to expose said crown portion.
27. A stent-graft delivery system comprising:
a stent-graft mounted on a pushrod;
a sheath for radially constraing said stent-graft;
a means for securing a crown portion of said stent-graft to said pushrod;
a means for retracting said sheath to expose said crown portion of said stent-graft; and
a means for releasing said crown portion from said pushrod during further retraction of said sheath.