摘要:
A scanning device for a magnetic-tape apparatus is proposed, which device comprises a stationary upper drum section (1) and lower drum section (2) and a head disc (10) which rotates in a gap (5) between the drum sections. In its upper radial surface and its lower radial surface the head disc (10) has segmental recesses (26, 27) for accommodating magnetic heads (11) secured to head mounts (12). At one side of the head disc (10) the recesses (26, 27) accommodate magnetic recording heads and at the other side said recesses accommodate the magnetic reproducing heads.
摘要:
A scanning device for a magnetic tape recording and playback equipment of the oblique track type has a drive shaft (9) for a rotary head wheel (4) mounted in a duplex ball bearing (10) centered on the orbit plane of the magnetic heads which revolve on the circumference of the head wheel between the two halves of a tape-guiding drum. A support bearing (19) is affixed in the bottom of a housing (17) which houses the drive motor and is held in a downward extending socket at the bottom of the lower half of the drum. The housing can be tilt-shifted slightly for shifting the support bearing and then held, by three screws accessible from below, in the correct position for aligning the orbit of the magnetic heads in the gap between the two halves of the drum.
摘要:
For oblique track scanning of magnetic tape which is looped around a two-part drum (1, 2) separated by a gap (5) in which magnetic heads (11) affixed to a headwheel revolve, the rotary transformers connecting the magnetic heads on the headwheel to fixed parts of the scanning device are provided by inner and outer magnetic core rings in which windings are embedded for a number of transformers. One group of these rotary transformers (18, 19) is located above the headwheel disk structure (10, 25) in such a way that outer magnetic core rings are fixed in a bore of the fixed upper drum (1) and inner magnetic core rings (19) are affixed to a seating shell (25) that connects the headwheel disk (10) to its driving shaft. Another group of rotary transformers (10, 21) is located beneath the rotary headwheel disk structure (10, 25) and in this case the outer magnetic core rings (20) are affixed to the inner wall of the rotary headwheel disk structure (10, 25) and the inner magnetic core rings are affixed to the outer wall of the bearing (15) of the shaft (14) that drives the rotary headwheel disk.
摘要:
A tape drive has two hubs which can each be rotated in forward and reverse direction. An arrangement is provided which permits each hub to be freely rotated in one direction while braking the other against rotation in the same direction, and vice versa.
摘要:
A ring-connected d-c brushless stator winding has winding sections (I, II . . . XI), serially connected by junctions (1, 2 . . . 11) and selectively and sequentially connected to a source of d-c power (15, 16) by controlled switches (20, 21), the connection of the switches being selectively controlled by a logic network responsive to a rotor position sensor (26). In accordance with the logic, when the rotor position sensor senses that the rotor is in alignment with a junction, the respective junction is connected to one terminal and, through the logic, which includes an OR-gate (28), a NOR-gate (29) and an AND-gate (30) which receive input signals from sensors associated with other junctions, the junction beneath the sensor sensing the rotor at the position is connected to one terminal of the source, whereas junctions effectively 180.degree.-electrical displaced are connected by the switches controlled by the logic, to the other d-c terminal; as the rotor moves, the field travels around the ring stator.
摘要:
To prevent external acceleration or deceleration forces from affecting the linear speed of a tape of a tape transport mechanism, counter-rotating masses are formed by the counter or pressure roller (13) engaging the tape and pressing the tape against the capstan (4'), the respective moments of inertia about the respective axes of rotation, and the respective radii being selected in accordance with the relationship ##EQU1## wherein j.sub.1 is the moment of inertia of the drive system about the axis of rotation of the drive capstan (4');r.sub.1 is the radius of the drive capstan (4');j.sub.2 is the moment of inertia of the counter or pressure roller (13) about its axis of rotation (14); andr.sub.2 is the radius of the counter or pressure roller (13).
摘要:
The density of winding of tape onto a reel at high winding speeds is improved by oscillatory longitudinal translation of a portion of the tape, to induce tape tension oscillations. This substantially precludes slipping of the layers on the reel. To initiate the tension oscillations, a tape tension controller in a video tape recorder is vibrated by a motor whose torque is varied periodically. In another embodiment, the spindle of a guide roller is mounted for eccentric rotation by a drive motor.
摘要:
For rotationally locking a motor shaft (16) to a head disc (10) one end of the motor shaft (16) is provided with a clamping hub (15). The clamping hub (15) comprises a clamping sleeve (27) in which two clamping elements (28, 29), spaced apart by a spacer tube (30) and extending in the direction of the axis of rotation, are axially movable. Two conical star washers (32, 33) are mounted between the individual clamping bolts (28, 29) and the ends of the spacer tube (30) and provide a centric expansion of the clamping tube (27) at two locations (38, 39).
摘要:
In a recording and reproduction device for a tape-like carrier having at least one scanning device and two spools for the carrier, first and second tape-tension adjusting levers, and first and second guidance devices disposed on the levers, respectively, for guiding and maintaining the carrier thereon, spring devices exerting a force against the levers, and where the levers may be displaced from a rest position to one of a plurality of operating positions against the force of the spring devices, the improvement includes a regulating mechanism for the spring device where the force of the latter has first, second and third regions, which may be controlled by the regulating mechanism. The force for the spring device may be adjusted by the regulating mechanism in the first region to a value sufficient to maintain the carrier on the guidance devices, is adjustable in the second region to a second value required for selective recording and reproduction of the carrier, and may be adjusted in the third region to a value at least equal to a value required for fast rewinding of the carrier, but below a predetermined maximum allowable value that if obtained, would result in a permanent deformation of the tape-like carrier.
摘要:
In a magnetic tape transport device having supply and take-up reels and tape guide elements, as well as a scanner, there is engaged with the tape on each side of the scanner a tape tension roller on the free extremity of a tape tension lever which is subjected to torque at its pivot by a d.c. motor for maintaining the desired tension of the tape. An angular position indicator is connected to the pivot of the lever and a regulation loop is provided for controlling the tape tension in a manner consistent with the tape speed. A capstan drive of the tape is not necessary.