1,135,902. Storage systems. E. N. CARABATEAS. 8 May, 1967 [18 May, 1966], No. 21312/67. Heading B8E. [Also in Division H2] Apparatus for storing and retrieving books comprises a separate holder 30, Fig. 5, for each book, a frame 10a, Fig. 1, including brackets 26, Fig. 4, for supporting a plurality of the holders in rows and columns, and a selector mechanism comprising a member 60 movable longitudinally of the frame and a carriage 66 mounted on the member 60 for vertical movement, the carriage having a finger 104 which is movable relative to the carriage towards and away from the frame and is adapted to releasably engage any holder whereby the latter can be moved between the carriage and the frame. The brackets 26 have notches (27), Fig. 6 (not shown), for interlocking engagement with notches (28) in support strips 22 carried by struts 24 of the frame. Each holder 30 consists of a U-shaped strap 32 connected to a ledge 34 having rollers 36 for facilitating movement and a handle 38 for engagement by the finger 104. The member 60 is attached to a cage 40 having rollers (42, 44), Fig. 3 (not shown), which run on a horizontal rail 12, and is moved by a motor 46 driving a belt 54 which is attached to the cage. The carriage 66 is attached to a chain 68 which extends over a sprocket 70 to a counterweight and is driven by a motor 72. The carriage has rollers 82 running on the member 60 and has a bracket 84 on which is rotatably supported in a bearing 87 a platform 86 carrying a cage 90 which includes corner parts 94 supporting bars 96 on which the holders run. The finger 104 is in screw-threaded engagement with a shaft 100 rotated by a motor 108 to move the finger. The upper part of the latter includes a tip (112), Fig. 7 (not shown), which is mounted for vertical movement for engagement with and disengagement from the handles 38 of the holders 30, the tip having a notch (114) and being mounted on a core (116) of a solenoid (118). Energization of the solenoid moves the tip upwardly into engagement and a return spring may be provided. A plurality of storage frames individually served by selector mechanisms are mounted in a room having walls separating them from users, and user openings (20), Fig. 2 (not shown), are provided into which selected books are placed by the selector mechanisms, the platform 86 of each being rotated by a motor 120 for this purpose, see also Fig. 6 (not shown). Contacts 130, Fig. 5, are spaced along the top of the frame 10a for co-operation with a bar 132 moving with the member 60, the contacts being included in a circuit controlling the stopping position of the member 60. A conventional multi-position switch may be used to connect any selected pair of the contacts in a control circuit of the motor 46. Similarly contacts 134 are provided on the member 60 for co-operation with a bar 136 on the carriage 66 to control the stopping position of the latter. The control circuit is also used to energize the motors for returning the books to the frame 10a. A control circuit for the carriage 66 is described with reference to Fig. 8. Selector switches 200a . . . 200n operated by the user are associated with contacts 134a . . . 134n associated with the rows of holders. If switch 200a is closed it energizes a holding relay 202a through its relay 204a. The relay 202a energizes the motor 72 through a line 206, and also the motor 108 to withdraw the finger 104; vertical movement of the carriage 66 is not possible unless the finger is withdrawn. When the bar 136 closes contacts 134a a braking unit 208 is energized to stop the carriage 66, and a timer unit 210 is energized to initiate movement of the finger 104 towards the book. The timer then sequentially energizes solenoid (118) to engage the fingertip (112) with the handle 38, reverses the motor 108 to withdraw the book and restarts the motor 72 so that the carriage 66 is positioned to correspond with the opening 20. The timer 210 may be a motor-driven multi-position switch having stationary contacts shaped and positioned so that a driven armature applies energizing signals thereto for preselected intervals at preselected times after the switch 134a is closed. A similar control circuit is provided for the motor 46 and includes contacts at the end of the rail 12 adjacent the opening 20 for energizing the motor 120 to rotate the platform 86. A weight-responsive switch (221) may be associated with the finger 104 or the carriage 66 for energizing a lamp when a selected book is not in storage. Coded cards may be provided on the holders for reading by a decoder when the holders are on the carriage 66, the decoder activating the selector mechanism so as to return the books automatically. The cards may also be used to indicate the location of books in the reading room, the users placing the cards in decoders located adjacent the tables in the room. Central means interrogate each decoder. The position of the books may be listed in a catalogue and the user presses a button corresponding to the book position selected to start the automatic operation of the apparatus. The selector mechanism may serve two storage frames disposed one on each side of the mechanism.