Patent GB-1490579-A (GB)
Title: Magnetic video recording and reproducing apparatus
IPC: G11B15/665
Filed: 1974-11-22
Abstract: 1490579 Video tape apparatus TEAC VIDEO CORP 22 Nov 1974 [24 Nov 1973] 50647/74 Heading G5R [Also in Division B8] A magnetic video tape recording and playback apparatus has a holder 210, Fig. 3, movable between a first position, for loading and unloading a tape cassette M in the holder, and a second position in which a cassette M in holder 210 is in its operative position, and a tape threader (81), Fig. 2A (not shown), for drawing tape from an operatively positioned cassette and wrapping it around a rotary video magnetic head assembly (60), the apparatus being for use with a tape cassette having a first wall (23), Figs 4A to 4D (not shown), with a non-central recess (205) extending in the direction of insertion of the cassette into the holder 210 and a second wall (19), opposite the first wall, without such a recess, and the apparatus further having holes 237, 238, Fig. 2B, in a wall 212 of holder 210, and a pivoted lever 233 with pawls 234, 235 at opposite ends thereof, lever 233 being arranged so that when the cassette is inserted in the holder 210 with its wall (23) in contact with holder wall 212, the pawl 235 extends freely through said hole 238 and into the recess (205) of the cassette wall (23) and allows full insertion of the cassette into the holder, whereas if the cassette is inserted into the holder 210 with its second wall (19) in contact with wall 212, the cassette engages pawl 235 thereby rotating lever 233 to a position in which pawl 234 projects through hole 237 to prevent the cassette from being fully inserted into the holder 210. The bottom wall (23) of the twin-reel cassette M for an opening 36, Fig. 2B, for receiving parts of the tape threader (81) which is of the type described in Specification 1,488,490, said recess in wall (23) being formed by a groove (205) extending rearwardly from opening 36. A cassettereceiving casing 219 of holder 210 for a cassetteinsertion opening 220 and is pivoted via pairs of arms 294, 296, 304, 306 to fixed support plates 291, 292. Wire springs 321, 322 bias casing 219 to its loading/unloading position, and the casing 219 maintained parallel to itself during its movement with the aid of gears 372, 373 fixed to a shaft 371 and engaging with toothed parts 374, 375 of support arms 296, 306. A spring biased latch 341, Fig. 1, is operable to hold casing 219 in the operative position and can be released by a lever 362. If the casing 219 is moved towards its operative position with the cassette M projecting out of opening 220, a spring biased plate 387, 388, 389 is engaged by the cassette M to prevent completion of such movement, this plate being operable, however, to engage the cassette and effect complete insertion into casing 219 if the cassette only projects slightly therefrom. The casing 219 includes two spring bands 241, 242 which engage between the top 216 of casing 219 and the top of the cassette to press the cassette against the bottom plate 212 of the casing 219, and during the movement of the casing 219 to the operative position levers 273, 274, Fig. 2B, are pivoted by engagement with parts of support arms 296, 306 so that spring biased elements 271, Fig. 1, on lateral arms 279 of levers 273, 274 press on portions (202), Figs. 4B, 4D (not shown) of bearings (21), (22) of reel shafts (13) in cassette M, which portions (202) project through the upper cassette wall (19), so that hubs 41, 42 of drive shafts 37, 38, Fig. 1, of the apparatus correctly engage in recesses (12) of the cassette reels (17), (18). If the apparatus is used with its main chassis surface 2 vertical, in which case return of casing 219 and cassette M to the loading/ unloading position would be aided by gravity, a buffer mechanism 410, Fig. 3, becomes operative to prevent the loading/unloading position being reached with a violent stopping action. Mechanism 410 has a lever 412, Fig. 6, 7 (not shown) and Fig. 3, pivoted at 411 to rest in an inoperative position against a stop 413 if surface 2 is horizontal. If the apparatus is moved so that surface 2 is vertical, lever 412 pivots to an operative position with a gear 415, rotatably mounted on lever 412, engaging gear 372, whereby gear 415 is rotated when casing 219 moves. A unidirectional drive coupling (419) transmits drive to a brake ring 418, braked by a pad (430), in such a way that motion of casing 219 from the operative to the loading/ unloading position is braked but not motion of casing 219 in the other direction.