Patent GB-1456897-A (GB)
Title: Cassette type magnetic tape recording and reproducing apparatus enabling automatic reversal of the running direction of the tape
IPC: G11B15/02
Filed: 1974-03-20
Abstract: 1456897 Cassette-tape apparatus AKAI ELECTRIC CO Ltd 20 March 1974 [21 March 1973] 12486/74 Heading G5R A magnetic tape recording and playback apparatus for twin reel tape cassettes has a control means 103, Fig. 4, arranged so that in a first position thereof a pinch roller 16, Fig. 1, engages a capstan 28 to drive the tape in one direction (forwards), and in a second position thereof a pinch roller 15 engages a capstan 27 to drive the tape in the opposite direction (backwards), capstans 27, 28 being driven in opposite directions by a common motor (73), Fig. 3 (not shown), an actuating member 93 being operable by an actuating means 79, 81, 82, 90, which is actuated when either tape end is detected, so that actuation of member 93 from a first position thereof changes over the position of control means 103 and from a second position thereof brings the apparatus into a stop state, positioning of member 93 in its first and second initial positions being controlled in accordance with the positions of both control means 103 and a manual setting means 126, Fig. 4, so that with means 126 in a first position (A), Fig. 8 (not shown), member 93 is in its second position, with means 126 in a second position (B) member 93 is in its first and second positions when control means 103 is respectively in its first and second positions, and with means 126 in a third position (C) member 93 is in its first position regardless of the position of control means 103. Rewind Rw, Fig. 1, playback P and fast forward F push buttons are all operable to release brakes (64), Fig. 2 (not shown), from drive rollers (65), (66) of tape reel drive hubs 53, 54, operation of playback button P also moving a sliding base 11 towards the cassette, base 11 carrying pinch rollers 15, 16, erase heads 13, 14 and playback/record head 12. Control means 103 is a slidable plate having a pin 111 to cause cause corresponding sliding of a slider 46 having abutments controlling rollers 15, 16 and having a pin 48 arranged so that when reverse drive is selected pin 48 lifts a lever 42 against a spring 45 allowing a spring to raise head 12 to align it with the second side of the tape. In an alternative embodiment a rotary record/playback head may be provided. When the end of the tape is sensed, photoelectrically or by sensing tape tension or by sensing stoppage of roller (66) by means of a reed switch operated by a magnet on a belt (138), Fig. 3, around roller (66), a solenoid 90, Fig. 4, is actuated thereby pivoting a lever 82 into the path of a pin 78 on flywheel 75 of capstan 28, pin 78 moving lever 82 longitudinally thereby causing actuating member 93 to slide a plate 94 forwards causing a lever 96 thereon to engage a lever 99 or 100 to move slider 103 to the left or right respectively to change over to reverse or forward tape drive respectively, plate 94 causing operation of a microswitch 136 thereby de-energizing solenoid 90 whereby springs return levers 79, 81, 82, 96, 99, 100 and plate 94 to a state in which lever 96 is ready to engage lever 100 or 99 respectively at the next end of tape. Manual tape reversal can be effected by pushbuttons 210, 211, Fig. 1, acting through a lever arrangement, Fig. 5 (not shown), on slider 103. Members 194, 195 engaged by sliders 186, 187 are operative to sense the presence or absence of removable lugs on the cassette and to prevent recording on a corresponding tape side in the absence of the corresponding lug. Playback with the setting means 126 formed by a slidable plate, in the A position, whereby member 93 is in a second part 234, Fig. 1, of a hole 139 in chassis 1, proceeds until the tape end is detected whereupon member 93 is actuated and, by reason of its location in part 234, does not effect drive reversal but moves a stop slider 119 operating via a lever 124 to release a locking plate 3 of the push-button selector unit thus stopping the machine. With plate 126 in the B position member 93 is initially in a first part 233 of hole 139 whereby when playback of one tape side ends member 93 is actuated to reverse the tape drive for playback of the second tape side, levers 114, 115 coupled to slider 103 causing member 93 to enter hole part 234 after the reversal whereby the machine is stopped at the end of the second side. With plate 126 in the C position, member 93 is caused to stay in hole part 233 whereby tape drive reversal repeatedly occurs at each end of the tape. Recording is selected by pressing buttons R and P together. A slider 198 is coupled to slider 103 so that parts 204, 203 of slider 198 engage pins 197, 196 respectively on sliders 187, 186 respectively to prevent pin 197 or 196 engaging in slot 160 or 159 respectively of a slider 154 when slider 103 is in the forward or reverse tape drive condition respectively, but allowing the other pin 196 or 197 to engage slider 154 in response to member 194 or 195 respectively sensing absence of a cassette lug whereby recording on the corresponding side of the cassette is prevented by locking slider 154 against movement by button R. When recording is selected with plate 126 in the A position, the machine is stopped at the end of the first side as for playback. When recording is selected with plate 126 in the B position and with a cassette of which the first side (forward drive) may be recorded on but the second side (reverse drive) may not, for example, member 195 senses the absence of the corresponding cassette lug and acts via levers 180, 177, 176 and slider 181 to cause member 93 to move to the second hole part 234 whereby the machine is stopped after recording on one side. If both sides are recordable the machine automatically reverses at the end of the first side and stops at the end of the second. If recording is selected with plate in the C position, operation of button R moves a slider 165 to the left causing a pin 170 to move plate 126 back to the B position, operation then being as described above. Fast winding or fast rewinding selection by button F or Rw respectively causes slider 61 to move lever 176 so that slider 181 moves member 93 into second hole part 234, or causes slider 57 to move slider 145 to the right whereby a part 147 thereof pushes member 93 into hole part 234. Thus, the machine is stopped automatically when all the tape has been wound on to one or the other reel.