1. A bladed rotor for a turbo-machine, the rotor having a rotational axis and comprising a hub defining a plurality of circumferentially spaced-apart slots around its periphery, each slot slideably receiving a root portion of a respective rotor blade, the root portion of each blade defining a radially inwardly open retaining groove within which a respective region of a retaining ring locates to retain the blades in said slots without the retaining ring making contact with a radially outermost region of the blade retaining groove, the retaining ring also engaging within a plurality of radially inwardly open hub grooves formed around the hub, wherein the retaining ring engages each said hub groove such that a radial gap is defined between the retaining ring and a radially outermost region of each hub groove.
2. A bladed rotor according to claim 1, wherein each said hub groove defines a respective radially outermost internal surface and the retaining ring engages the hub grooves in radially spaced relation to said radially outermost internal surfaces.
3. A bladed rotor according to claim 1, wherein said engagement of the retaining ring within said hub grooves is effective to maintain a radial gap between the retaining ring and a radially outermost region of each said retaining groove.
4. A bladed rotor according to claim 1, wherein said retaining ring defines a first contact surface on a first flank of the ring for engagement within each said hub groove, said first contact surface lying at an acute angle to a plane orthogonal to the rotational axis of the rotor.
5. A bladed rotor according to claim 4, wherein said hub grooves each define a corresponding internal contact surface for contact with said first contact surface of the retaining ring, each said internal contact surface lying at a substantially equal acute angle to a plane orthogonal to the rotational axis of the rotor as said first contact surface of the retaining ring.
6. A bladed rotor according to claim 5, wherein said retaining ring is urged into engagement with said hub grooves such that said first contact surface of the retaining ring makes contact with the internal contact surface of each hub groove over a contact area which is greater than the area of the radially outermost internal surface of each hub groove.
7. A bladed rotor according to claim 4, wherein said retaining ring defines a second contact surface on an oppositely directed flank of the ring and which lies in a plane orthogonal to the rotational axis, the second contact surface of the ring being urged into contact with a radial surface of the hub.
8. A bladed rotor according to claim 7, wherein said second contact surface of the retaining ring is also urged into contact with a respective radial surface of the root portion of each rotor blade.
9. A bladed rotor according to claim 8, wherein said second contact surface of the retaining ring extends radially across an interface between the hub and the root portion of each rotor blade at the circumferential position of each rotor blade.
10. A bladed rotor according to claim 4, wherein said retaining ring has at least a region which is tapered in radial cross-section so as to narrow in a radially outward direction.
11. A bladed rotor according to claim 10, wherein said region of the retaining ring is frustoconical in radial cross-section.
12. A bladed rotor according to claim 1, wherein said retaining ring is radially outwardly biased.
13. A bladed rotor according to claim 12, wherein the radially outwards bias of said retaining ring is effective to urge the retaining ring into said engagement with said hub grooves.
14. A bladed rotor according to claim 1, wherein said hub grooves are circumferentially interspaced between said retaining grooves.
15. A bladed rotor according to claim 1 provided in the form of a compressor rotor for a gas turbine engine.
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 ink-jet printing method for generating MICR-readable indicia comprising:
a. preparing MICR ink-jet ink containing a magnetic particulate material in an amount sufficient to generate a minimally readable MICR signal level of lower than the nominal signal value of 100 according to the standard signal level specification defined by ANSI when printed in single pass mode;
b. charging the MICR ink-jet ink containing the magnetic particulate material to a multiple-chamber ink-jet ink cartridge such that each charged chamber of the cartridge contains the same MICR ink-jet ink composition;
c. installing the multiple chamber ink-jet ink cartridge in a full color process printer;
d. operating the printer in a multiple pass manner to print indicia having multiple layers of MICR ink-jet ink;
wherein the multiple layers of MICR ink-jet ink produce an additive effect with regard to the magnetic signal generated by the printed indicia such that the signal strength is increased in a manner corresponding to the number of layers of the MICR ink-jet ink which have been printed, as compared to the signal strength generated by indicia printed with a single pass of the same ink.
2. The ink-jet printing method of claim 1 wherein the multiple-layer indicia generates a MICR signal level of from about 100 to about 200.
3. The ink-jet printing method of claim 1 wherein the MICR ink-jet ink comprises at least a magnetic iron oxide and an ink.
4. The ink-jet printing method of claim 3 wherein the magnetic iron oxide is contained in a dispersion comprising at least the magnetic iron oxide, water and a surfactant.
5. The ink-jet printing method of claim 4 wherein the dispersion is further combined with a non-magnetic ink-jet ink composition.
6. The inkjet printing method of claim 1 wherein the MICR ink-jet ink contains at least 10% but not greater than 30% magnetic oxide, based on 100% of the MICR ink-jet ink composition.
7. A method of printing MICR-readable indicia capable of generating a MICR signal value of from 100 to 200, according to ANSI specifications, from ink-jet ink that has a minimal magnetic pigment content, comprising charging a MICR ink-jet ink containing at least 10% but not greater than 30% magnetic oxide, based on 100% of the MICR ink-jet ink composition, to at least two chambers of a multiple-chamber ink-jet ink cartridge, installing the cartridge in a full color process printer, and operating the printer to eject the MICR ink-jet ink from the cartridge chambers to print indicia, such that the number of layers of ink in the printed indicia is equal to the number of chambers in the cartridge that contain the MICR ink-jet ink, wherein the printed indicia generates an ANSI MICR signal strength value increase equal to approximately the number of layers of ink deposited times the signal strength value of a single layer of the same MICR ink-jet ink.
8. The method of claim 7 wherein the MICR ink-jet ink is charged to all chambers of the multiple-chamber ink-jet ink cartridge.
9. The method of claim 7 wherein the printed indicia generates an ANSI MICR signal strength of from about 100 to about 200.
10. The method of claim 7 wherein the MICR ink-jet ink, if printed in a single pass mode, generates an ANSI MICR signal strength value of less than 100.
11. The method of claim 7 wherein the MICR ink-jet ink, if printed in a single pass mode, generates an ANSI MICR signal strength value of less than 80.
12. The method of claim 7 wherein the MICR ink-jet ink contains not less than 15% but not greater than 25% magnetic oxide, based on 100% of the MICR ink-jet ink composition.
13. A MICR-readable document comprising a substrate having printed thereon indicia capable of generating a MICR signal of greater than or equal to the nominal value according to the ANSI standard for the same, the indicia comprising at least two layers of a MICR ink-jet ink composition wherein each layer alone is only capable of generating a MICR signal of less than the nominal value according to the ANSI standard for the same, but wherein the additive effect of the layers generates a MICR signal of greater than or equal to the nominal signal value according to the ANSI standard for the same.
14. The MICR-readable document of claim 13 wherein the MICR signal generated by the indicia is between about 100 and about 200.
15. The MICR-readable document of claim 13 wherein each layer of the indicia alone generates a MICR signal of not greater than 80.
16. The MICR-readable document of claim 13 also comprising indicia printed with only a single layer of ink-jet ink, such that a portion of the document is MICR-readable and the remaining portion of the document generates a MICR signal below 80.
17. The MICR-readable document of claim 13 wherein the indicia appears to be black.
18. The MICR-readable document of claim 13 wherein the indicia is printed in one or more colors.
19. A MICR ink-jet ink composition comprising at least a magnetic iron oxide dispersion and an in-jet ink, wherein the magnetic iron oxide is present in the ink composition in an amount less than that necessary to generate a nominal MICR signal value of 100, as defined by ANSI specifications.
20. The MICR ink-jet ink composition of claim 19, wherein the magnetic iron oxide dispersion comprises at least iron oxide and water.
21. The MICR ink-jet ink composition of claim 19, wherein the magnetic iron oxide dispersion comprises iron oxide, water and a surfactant.
22. The MICR ink-jet ink composition of claim 19, wherein the MICR ink-jet ink contains urea.
23. The MICR ink-jet ink composition of claim 19, wherein the ink-jet ink is a pigment-based ink.
24. An ink-jet printing method for printing MICR-readable indicia comprising:
a) charging at least two chambers of a multiple-chamber ink-jet ink cartridge with a MICR ink-jet ink capable of generating a MICR-readable signal; and
b) operating a printer in which the multiple-chamber ink-jet ink cartridge has been installed to print MICR-readable indicia by full color process printing,
wherein the signal value generated by the printed indicia, as measured by ANSI specifications, is between 100 and 200.
25. The inkjet printing method of claim 24, wherein each filled chamber of the multiple-chamber ink-jet ink cartridge is charged with the same ink-jet ink.
26. The ink-jet printing method of claim 24, wherein all chambers of the multiple-chamber ink-jet ink cartridge are charged with MICR ink-jet ink.
27. The ink-jet printing method of claim 24, wherein all but one chamber of the multiple-chamber ink-jet ink cartridge are charged with MICR ink-jet ink.
28. The ink jet printing method of claim 27 wherein the one chamber of the multiple-chamber ink-jet ink cartridge is charged with non-MICR ink-jet ink.
29. The ink-jet printing method of claim 24, wherein the indicia printed with the MICR ink-jet ink generates a MICR signal value of less than 80 when printed in a single pass mode.
30. The ink-jet printing method of claim 24 wherein the indicia is black.
31. The ink-jet printing method of claim 24 wherein the indicia is a color or colors other than black.