Abstract: A device for reciprocally rotating an output element such as a scanning mirror by means of an electric motor employs a two-degree-of-freedom suspension in which the motor armature is constrained by a first torsional suspension and the output element is supported from the armature by an independent second suspension. The resonant frequency of the armature and its suspension is substantially equal to the resonant frequency of the output element and its suspension.

Abstract: A velocity-compensation circuit for a limited-displacement motor comprises a bridge circuit incorporating the control winding of the motor in a first arm. An adjacent bridge arm includes both an inductance and a resistance whose ratio is the same as that of the first bridge arm. The bridge is balanced to eliminate from its output the effect of current through the control winding. The bridge output in normal operation is therefore solely a function of motor velocity and this signal is fed back to provide velocity compensation for the motor.

Abstract: A vibration damper for a transducer positioning system of a diskette system employing a stepping motor for driving a moveable transducer carriage that is coupled to the stepping motor drive means. The mass of the carriage and the coupling means form a vibratory system having a natural frequency of oscillation significantly different from the frequency of the pulses applied to the stepping motor so that while the motion of the carriage reflects the total motion of the shaft, the incremental motions of the shaft are not transmitted to the carriage thereby minimizing noise ancillary to the positioning of the carriage.

Abstract: An optical scanner capable of scanning parallel to two intersecting axes. The scanner comprises a single electromechanical transducer and a compliant link interconnecting the transducer with an optical element to which the two-axis movement is to be imparted. The link is selectively compliant to two planes containing the two axes and it is oriented to receive from the transducer force components in both planes. The transducer is driven at the frequencies of the resonances associated with the link compliances and the masses involved therewith. The link thereby imparts amplified motion to the optical element simultaneously in both planes, the resulting path described by the element thus being a Lisssajous pattern.

Abstract: Apparatus for moving a transducer carriage intermittently along a tract relative to a recording medium employs belting arranged in a closed loop that is tensioned by engagement around at least one idler and connected to the carriage. Belt end segments comprising the loop are wrapped in opposite directions around the periphery of a stepping motor-driven capstan and their ends are secured thereto at axially spaced apart locations thereon. The belting and idlers are arranged so that all of the belt segments wrapped around the capstan remain parallel to the carriage track as the capstan rotates so as to advance the carriage a maximum number of increments along its track.

Abstract: The armature of a limited-rotation motor which rotates about an axis relative to a stator is extended axially beyond the stator between arcuate, non-magnetic capacitor plates disposed in a cylindrical array coaxial with the rotation axis. The capacitor plates are connected in a bridge circuit whose output is a selected function of armature displacement. The capacitor plates are installed at the end of the motor stator during assembly of the motor as tines of a unitary slotted bushing that is reamed simultaneously with the motor stator, following which the bushing is circumferentially cut to electrically isolate the bushing tines to form the individual plates.

Abstract: The armature of a limited-rotation motor which rotates about an axis relative to a stator is extended axially beyond the stator between arcuate, non-magnetic capacitor plates disposed in a cylindrical array coaxial with the rotation axis. The capacitor plates are connected in a bridge circuit whose output is a selected function of armature displacement. The capacitor plates are installed at the end of the motor stator during assembly of the motor as tines of a unitary slotted bushing that is reamed simultaneously with the motor stator, following which the bushing is circumferentially cut to electrically isolate the bushing tines to form the individual plates.

Abstract: A signal generator for producing signals indicative of the speed of tape driven reel to reel in a tape cassette transport in lieu of timing signals recorded directly on the tape is used to control the reel motors that drive the cassette. The tape-engaging drive wheel is designed to minimize slippage between the moving tape and the drive wheel so that the generator output accurately reflects tape speed.

Abstract: A line printer for printing successive lines of information on a ticket. As the ticket is guided toward ticket printing and advancing mechanisms, a first ticket sensor energizes a latch circuit and shifts the ticket advancing mechanism from a normally closed condition to an open condition. The ticket then moves freely into the printer to a predetermined position defined by a stop. A second ticket sensor at the stop is then actuated to close the ticket advancing mechanism and enable ticket advancement.

Abstract: An escapement mechanism for driving a shaft about an axis in a line printer each time a solenoid is actuated. An armature in the solenoid moves along a second axis which is normal to the axis of rotation and intersects it. An integrally molded escapement arm is pivotally mounted to the armature and also to a frame for rotation about a third axis which is parallel to the axis of shaft rotation and is spaced from the second axis. A resilient spring on the escapement arm engages a ratchet wheel mounted on a shaft. When the solenoid is actuated, the armature withdraws the escapement arm and the spring. When the solenoid is de-energized, a return spring on the solenoid advances the armature so the drive member engages the ratchet wheel and rotates the shaft. A second ratchet wheel oppositely oriented with respect to the first engages a positioning member on the escapement arm thereby to orient properly the shaft.

Abstract: The armature of a limited-rotation motor which rotates about an axis relative to a stator is extended axially beyond the stator between arcuate, non-magnetic capacitor plates disposed in a cylindrical array coaxial with the rotation axis. The capacitor plates are connected in a bridge circuit whose output is a selected function of armature displacement. The capacitor plates are installed at the end of the motor stator during assembly of the motor as tines of a unitary slotted bushing that is reamed simultaneously with the motor stator, following which the bushing is circumferentially cut to electrically isolate the bushing tines to form the individual plates.