Patent GB-1248520-A (GB)
Title: Cassette changer
Inventor: VAIL THOMAS WILLIAM
IPC: G11B15/28
Filed: 1969-11-21
Abstract: 1,248,520. Cassette players. WARWICK ELECTRONICS Inc. 21 Nov., 1969 [21 Nov., 1968], No. 57204/69. Heading G5R. A sequential access tape cassette changer includes a probe arrangement for sensing the presence of a cassette at a playing position and for sensing whether the tape in the cassette is blank or pre-recorded. The cassettes C are loaded into a holder 44 movable along a track 42 under spring force 126 then pushed to the start position (left in Fig. 1). The machine functions are generally controlled by a manually- or solenoid-operated slide 60 having portions connected through various linkages to the parts to be controlled. On lowering the slide 60, a portion 72 engages the end of a lever 76 connected by a linkage (Figs. 11, 12, not shown) operating a pair of pawls (114, 130) forming an escapement mechanism co-operating with a rack on the cassette holder 44, thereby indexing the holder one cassette position, whilst a further portion 70 engages a lever 74 coupled so as to retract the sensing probe (154, Fig. 13, not shown) to permit the above movement. After indexing, the probe rises so as to pass through an aperture in the base of the holder and to operate a set of contacts depending on whether the probe engages a knock-out cassette portion to indicate that the cassette is blank, enter the cassette to indicate the tape is pre-recorded or extend its full extent through the holder when a cassette is absent. A solenoid 400 is thereby operated to lower the slide and initiate a further indexing cycle accordingly, e.g. to search for a blank tape if a recording operation is desired upon depression of the record button (230) and corresponding operation of a record interlock switch (circuit,Fig. 14, not shown). When the last cassette has been played and the holder is indexed again, a cam 500 on the holder operates a linkage 501, 506 to press a roller 512 against a universally pivoted lever 515 to position a further roller 520 in the path of a projection 521 on the slide so that when the probe operates to energize the solenoid 400 the slide 60 is lowered and the lever 515 causes a further slide 430 to rise and interpose a slide 440 in the path of the slide 60 to prevent a further indexing cycle and to latch the slide 60 in this position. A further linkage 338, 335, 329, 325 coupled to the slide 60 is connected to a bridge 333 carrying record/ play and erase heads, a pinch roller and a tape tension sensor to raise the assembly clear of the cassettes when the slide 60 is lowered. The sensor operates a microswitch 359 to initiate an indexing cycle at the end of play of a cassette. The slide latch is released when the holder or stop-button are released. A stop switch 460 is operated by the slide 430. Drive mechanism.-The casptan and drive shafts extend through all the cassettes and have operative portions at the location of the bridge 333. For support, the capstan shaft (266, Fig. 15, not shown) is centred in a tube 277 of such dimensions as to enter, and be supported by, the normal capstan opening in the cassettes, whilst the drive to the shafts 262, 263 is controlled by idlers 282, 283, 290 and 296 whose positions are controlled by the appropriate pushbuttons.