Abstract: A fully automatic microcomputer-controlled tape cartridge handling system. As illustrated here, it has a high degree of redundancy providing maximum reliability in radio broadcasting service and other applications. It comprises two storage drums, four stacks of playback transducers, two cartridge transfer mechanisms, a loading chute, and an unloading chute. Each drum has a cylindrical configuration with 512 cartridge storage compartments arranged in 16 vertical columns around its circumference and 32 horizontal rows along its axis. Two transducer stacks and one transfer mechanism are on each side of the pair of drums. Each transfer mechanism is positioned adjacent both drums and positioned adjacent two of the transducer stacks, one of the transfer mechanisms also being adjacent the loading and unloading chutes. Each transfer mechanism has a cage which is selectively rotatably swingable to positions aligned with either drum or either adjacent transducer.

Abstract: A combined eraser and splice finder for an NAB tape cartridge which comprises apparatus for subjecting an NAB tape cartridge to an initially strong and thereafter diminishing and vanishing oscillating magnetic field for bulk tape erasure and which, independently or at the termination of the erasure cycle, also senses the presence of the tape splice and stops tape travel within the cartridge at a point where subsequent recording can begin immediately behind the splice. The apparatus is capable of erasure without splice-finding or splice-finding without erasure.

Abstract: A magnetic transducer head having, at the face end wall, at least one pair of transducer pole piece portions extending in the direction of movement of the tape and having a gap between them. The pole pieces are tangent, at the gap, to a base plane parallel to the general direction of movement of the tape. In the example illustrated, the pole piece portions are disposed at approximately 13.degree. relative to the base plane so that the spacing between the pole piece portions and the base plane increases with distance from the gap on both the approach to and retreat from the gap. The casing has a tape guide surface which overlies the pole piece portions at the face end wall and determines the angle of approach to and retreat from the pole piece portions. This guide surface is cylindrical in the example illustrated, providing an approximately 7.degree. angle of approach and retreat of the tape relative to the base plane, this being substantially less than the 13.degree.

Abstract: An optical seed sensor for a seed planter monitor utilizes light emitting diodes and a rapidly-responding light-receiving solar cell mounted in a seed dispensing chute. A solar cell light shield with a slit narrower than the diameter of a typical seed is mounted adjacent to the solar cell. When a seed passes the light shield, the voltage output of the light-receiving solar cell is temporarily reduced in response to a change in intensity of light at the solar cell. Electronic circuitry converts such solar cell voltage fluctuations into electrical counting pulses for the seed planter monitor. The rapidly-responding solar cell, the partially shielded solar cell and the electronic circuitry cooperate to discriminate between closely spaced or partially overlapping seeds passing through the dispensing chute in order to achieve accurate seed counting.

Abstract: A fully manually adjustable embodiment has a base member fastened to and spaced from a tape deck frame. Two identical mounting block members are provided, one for a recording head and one for a reproducing head. A rear portion of each mounting block member is positioned in the space between the base member and the tape deck frame. Three balls, loosely retained in cylindrical bores in the bottom face of the base member, are seated in spherical recesses in the top face of each mounting block member. An adjusting screw, threadedly engaged with the base member, extends into each cylindrical bore, engaging the corresponding ball. Tension springs are connected between pins in the base member and each mounting block member to draw them toward one another and thereby engage the balls between the adjusting screws and the spherical recesses. Two of the balls on each mounting block member are located along a central axis of the head to establish an azimuth axis.

Abstract: A dual capstan tape transport mechanism having a magnetic tape trained along a path for movement successively between an upstream capstan and pressure roller, past record and play heads, and between a downstream capstan and pressure roller. A motor drives the downstream capstan directly and drives the upstream capstan indirectly, and slightly slower, through an overrunning clutch. Separate solenoids move the pressure rollers to press the tape against the respective capstans. The mechanism is selectible to play either an improved dual capstan type cartridge with both capstans, or to play a conventional single capstan type cartridge with the downstream capstan alone. Tape guide posts, aligning the tape and providing wrap around the heads, and a shield engageable with the backside of the tape opposite the play head, are movable with the upstream pressure roller through openings in the housing of the dual capstan cartridge.

Abstract: Reproducing apparatus for magnetic tape in which the forward and rewind torques motors are series-interconnected to moderate their torques and limit the tape tension during play mode only, thereby eliminating the large heat-generating resistors required when the torque motors are parallel-connected by the conventional arrangement. Relatively small variable resistor means is provided in the power supply to the series-interconnected torque motors, enabling adjustment of tape tension in the play mode. In the specific embodiment illustrated, the variable resistor means comprises two individual resistors. Switch means selectively connects one or both resistors into the torque motor power supply circuit to keep tape tension within a predetermined range during play mode for different size tape reels.

Abstract: Automatic azimuth control for a multi-track magnetic tape recorder-reproducer. This is illustrated as stereo apparatus having a recording head with right and left recording gaps through which signals are recorded respectively on right and left tracks on the tape, and a reproducing head with right and left reproducing gaps through which the signals on the right and left tracks are reproduced. An azimuth control circuit simultaneously starts the tape drive and actuates a tone generator to record test signals in phase on the tape tracks. The test signal reproductions from the respective right and left gaps of the reproducing head are fed to a phase comparator which senses their time relationship. An azimuth motor, responsive to this time relationship skews one of the heads relative to the tape in a direction to bring the test signal reproductions into phase with one another. When they are brought into phase, the azimuth control circuit is automatically deactuated and the tape drive is stopped.

Abstract: A dual capstan tape transport mechanism having a magnetic tape trained along a path for movement successively between an upstream capstan and pressure roller, past record and play heads, and between a downstream capstan and pressure roller. A motor drives the downstream capstan directly and drives the upstream capstan indirectly, and slightly slower, through an overrunning clutch. Separate solenoids move the pressure rollers to press the tape against the respective capstans. The mechanism is selectible to play either an improved dual capstan type cartridge with both capstans, or to play a conventional single capstan type cartridge with the downstream capstan alone. Tape guide posts, aligning the tape and providing wrap around the heads, and a shield engageable with the backside of the tape opposite the play head, are movable with the upstream pressure roller through openings in the housing of the dual capstan cartridge.

Abstract: Solenoid has a coil which when energized moves a plunger inwardly through an opening in the housing against an external biasing spring which moves the plunger outwardly when the coil is deenergized. The front end wall of the housing has a plurality of bores disposed radially to the axis of movement of the plunger, each having a ferrous guide sleeve with an open end adjacent the plunger and a loose magnetic steel ball which is freely movable therein toward the plunger when the coil is energized. The plunger has an external groove within which the balls are seated when the plunger is in a fully retracted position. This enables the balls to extend from the open inner ends of the guide sleeves into latching positions holding the solenoid against outward movement. A much smaller electric power input is required in the coil to hold the balls in latched position, and therefore hold the plunger in retracted position, than is required to move the plunger to that position in the first place.

Abstract: Reproducing apparatus for magnetic tape having a pressure roller mounted on a first movable member and a tape lifter mounted on a second movable member. Solenoid and spring means connected to the first movable member moves the pressure roller between a tape-driving position pressing the tape into frictional driving engagement with a capstan, and a non-tape-driving position spaced from the capstan. Mechanical connecting means between the movable members moves the tape lifter between lifted and lowered positions in response to movement of the first member between its non-tape-driving and tape-driving positions. The mechanical connecting means includes a lost motion connection enabling manual override movement of the tape lifter between its lifted and lowered positions when the first member is in its non-tape-driving position for fast mode operation. This enables manual adjustment of tape proximity to the head, and therefore adjustment of audio output level while editing or scanning the tape in a fast mode.

Abstract: In a magnetic tape reproducer, tape lifer bars are rectilinearly movable in one direction by activation of a solenoid to engage the tape and lift it from the heads. The bars are movable in the opposite direction by a biasing spring, when the solenoid is deenergized, so the tape can contact the heads. A cover gate is mechanically connected to the bars and acts as a handle to cause the bars to move the tape back and forth toward the heads.A control circuit includes a normally closed play switch and a resistor connected in series with the solenoid. A bypass conductor parallels the resistor and has normally open fast forward and rewind switches in parallel with one another and in series with a normally closed edit switch. The play switch automatically opens and deenergizes the solenoid, the biasing spring moves the bars out of engagement with the tape which runs forward at play speed while the signal on the tape is reproduced through audio output means.

Abstract: A tape marker for a tape playing machine in which tape runs past a reproducing head in a housing compartment. The compartment has a door through which tape is inserted and withdrawn when the tape is changed or edited. A marking arm having an inked marking pad is pivoted to a sleeve which is mounted on a removable compartment cover so the tape marker and cover comprise a unitary sub-assembly. A pushbutton guided in the sleeve is connected to the marking arm by a double-pivoted link. Manual depression of the pushbutton swings the marking arm to press the ink pad against the tape. A narrow rib on the tape side of the pad prints a line on the tape at the exact center of the reproducing head. When the pushbutton is released, a return spring moves it outward and swings the marking arm and pad to a stored, out-of-the-way position providing clearance for the tape when inserted or withdrawn through the door.