1. An electrical contact with double-knife coupling, particularly for disconnectors, switches or the like, comprising a main contact pin and two mutually facing knives which can move toward or away from each other, said knives being movable together in order to pass from an active position, in which they engage said main contact pin with their mutually facing faces, to an inactive position, in which they are disengaged from said main contact pin, or vice versa; a spacer being interposed between said knives and limiting the maximum mutual approach of said knives in order to allow the insertion of said main contact pin between said knives in their transition from said inactive position to said active position, and elastic means being provided which contrast elastically the mutual spacing of said knives starting from the condition of maximum mutual approach in order to maintain the contact of said knives, in said active position, with said main contact pin, and further comprising means for indicating the degree of wear of the region of contact of said knives with said main contact pin.
2. The electrical contact according to claim 1, wherein said means for indicating the degree of wear comprise a connecting pin, which mutually connects said knives in a detection region, which is spaced from their region that can engage said main contact pin, and is arranged so that its axis is perpendicular to the mutually facing faces of said knives; said knives being able to slide along said connecting pin toward each other, due to the action of said elastic means, or away from each other due to engagement with said main contact pin; an indicator being fitted on said connecting pin and being lockable on said connecting pin by the contact of said knives against the axial ends of said indicator; said indicator having dimensions, parallel to the axis of said connecting pin, which correspond to the maximum mutual acceptable approach, at said detection region, for said knives in engagement with said main contact pin.
3. The electrical contact according to claim 2, wherein said indicator comprises a sleeve, which is fitted around said connecting pin and whose axial ends face the mutually facing faces of said knives; said sleeve being able to rotate freely with respect to said connecting pin about its own axis in the absence of contact of said knives against its axial ends.
4. The electrical contact according to claim 1, wherein said knives are substantially parallel to each other and in that said sleeve has an axial length equal to the dimensions of said main contact pin along a direction which is perpendicular to the planes of arrangement of said knifes minus the acceptable wear for said knives along the same direction.
5. The electrical contact according to claim 3, wherein said spacer is constituted by said sleeve.
6. The electrical contact according to claim 3, wherein said sleeve can slide freely axially along said connecting pin in the absence of contact of said knives against its axial ends.
7. The electrical contact according to claim 3, wherein the outer lateral surface of said sleeve is knurled.
8. The electrical contact according to claim 1, wherein said connecting pin passes coaxially through two through holes, which are formed in said knives and are mutually aligned along a direction which is perpendicular to the planes of arrangement of said knives; said connecting pin having, at its axial ends, two portions which form two mutually opposite shoulders which engage the faces of said knives that lie opposite with respect to the mutually facing faces; said two portions of the connecting pin being movable away from each other in contrast with said elastic means.
9. The electrical contact according to claim 8, wherein said elastic means are contained within the axial dimensions of said connecting pin.
10. The electrical contact according to claim 8, wherein said elastic means are accommodated in said connecting pin.
11. The electrical contact according to claim 1, wherein said connecting pin comprises a substantially cylindrical body inside which there is a coaxial cylindrical cavity starting from one of its axial ends; a first one of said two portions being constituted by a flange of the lateral surface of said body at said axial end, the second of said portions being associated with a shaft which is accommodated coaxially within said cavity and protrudes from the axial end of said body that lies opposite with respect to the axial end provided with said flange, said elastic means being accommodated in said body and being interposed between the bottom of said cavity and the axial end of said shaft that lies opposite with respect to the end that supports said second portion.
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 method of providing a media cartridge to a data storage and retrieval system, comprising:
inserting at least one media cartridge into a first opening of a cartridge storage device, wherein access to said first opening is provided by an opening in the data storage and retrieval system, the first opening being accessible when the cartridge storage device is fully inserted in the data storage and retrieval system;
removing said at least one media cartridge from said cartridge storage device from a second opening thereof, wherein said second opening is on an opposite side of the cartridge storage device than the first opening, the at least one cartridge being movable along a path of movement between the first and second openings, wherein the openings respectively lie on lines tangent to the path of movement of the at least one cartridge through the cartridge storage device and generally parallel to a portion of the path of movement of the at least one cartridge through the cartridge storage device; and
inserting said at least one media cartridge into a tape drive of said data storage and retrieval system.
2. The method according to claim 1, further comprising retrieving information about the at least one media cartridge in the cartridge storage device using a method selected from a group consisting of: viewing the at least one media cartridge in the cartridge storage device, reading a nonvolatile memory of the at least one media cartridge, and optically scanning the at least one media cartridge.
3. The method according to claim 1, further comprising simultaneously performing the method of claim 1 using a second cartridge storage device, a second at least one media cartridge, and the same data storage and retrieval system.
4. The method according to claim 1, further comprising removing the cartridge storage device from the data storage and retrieval system and coupling the cartridge storage device to a second data storage and retrieval system.
5. The method according to claim 1, wherein the cartridge storage device comprises a housing having a front and a back; a plurality of cells in the housing, each cell adapted for receiving a media cartridge; and a drive mechanism for selectively driving the cells towards the second opening of the housing, the second opening allowing insertion and retrieval of the cartridges from the cells.
6. A data storage and retrieval system, comprising:
a plurality of slots adapted for receiving system components;
at least one drive for reading data from a media cartridge;
at least one cartridge storage device capable of storing several of the cartridges, the at least one cartridge storage device having a front side, a back and sidewalls extending between the front side and the back, the at least one cartridge storage device being positioned in the slot front side first, wherein each slot in which a cartridge storage device is positioned has an opening for allowing access to the front of the cartridge storage device while inserted in the slot; and
a picker for retrieving and inserting cartridges from the at least one cartridge storage device and transporting the cartridges between the at least one drive and the at least one media storage device,
wherein at least one of the cartridge storage devices is not adjacent to any of the drives.