Today's large scale computer rooms typically employ human technicians which manually load magnetic data storage media (e.g. magnetic tapes) onto computer drives. With the recent advent of computer tape cassettes (i.e., as represented by the IBM 7575 system), the space requirement for physically cataloging and storing the magnetic media has decreased (due to the decreased size of these tape cassettes as compared to the more conventional magnetic tape spools).
However, human intervention is still typically required when a tape cassette must be removed from, or inserted into, a computer's tape drive. In my related copending application Ser. No. 07/182,593, there is disclosed a novel robot transport system having particular utility in the automated archiving and retrieval of computer data tape cassettes. In particular, the robot transport system disclosed in that application allows computer tape cassettes to be moved between a tape storage facility (where individual tape cassettes are archived) and a tape drive section (composed of individual tape drive units). It is preferred, according to the system according to that application, for the tape storage facility and tape drive section to be arranged serially along one side of the robot transport's path of conveyance.
While in some computer room applications, the preferred physical equipment layout in my copending application Ser.. No. 07/182,593 is entirely satisfactory, it would be desirable (in the interests of conserving computer room space) if a more compact arrangement and disposition of equipment were provided. At the same time it would especially be desirable if the storage capacity and/or tape drive capacity could be arranged so that each is easily expanded (e.g., by the addition of one or more tape storage and/or tape drive units) without significant disruptive effects upon the operation of the system. It is towards achieving such improvements that the present invention is directed.
An easily expandable automated computer tape cassette archiving and retrieval system is disclosed herein which includes a tape cassette storage facility and a pair of tape drive sections (each including at least one tape drive adapted to receiving preselected tape cassettes). The tape drive sections are disposed in spaced relation to the tape storage facility on respective opposite lateral sides thereof. A pair of robot transport assemblies (which may be of the track and carriage type disclosed in my copending U.S. application Ser. No. 07/182,593) are provided such that each operates in a respective one of the spaces defined between the tape storage facility and the laterally disposed tape drive sections.
The system of the present invention is therefore advantageous since a pair of robot transports can operate simultaneously to move tapes between the tape cassette storage facility and its associated tape drive section. The operation of multiple robot transports thereby makes it possible to increase the rate at which tape cassettes are transferred between the tape storage facility and the tape drive sections--i.e., since more than one robot transport is capable of operation without interfering with the other robot transport at any given time.
In addition, according to the present invention, a pair of opposing robot transports may be operatively associated with each of the respective tape drive sections--that is, by providing a primary and an auxiliary robot transport carriage on a single set of tracks associated with each of the tape drive sections. According to this aspect of the invention, the control system may be programmed so that the primary and auxiliary robot transports alternately move tape cassettes between the tape storage facility and their respective tape drive section without interference. Alternatively, the primary robot transport may be employed continually as the means to move tape cassettes between the tape storage facility and its respective tape drive section, with the auxiliary robot transport being maintained as an available stand-by in the event the primary robot transport malfunctions. In such a manner, the efficient operation of the computer system would not be comprised by down time associated with the primary robot transport.
The tape storage facility and/or the tape drive sections may be readily expanded simply by adding additional tape cassette storage units and/or tape drive units, respectively. This expansion may, moreover, be accomplished without significant disruption of the already existing tape cassette storage and drive units. At the same time, the longitudinal space required for such expansion is minimized, while the tape cassette storage and tape drive capacities for a given space are maximized. This, in turn, results in more efficient space utilization for the computer room in which the present invention is employed.
Other aspects and advantages of this invention will become more clear to the reader after careful consideration is given to the detailed description of the preferred exemplary embodiments thereof which follow.