Abstract: The invention relates to a system for monitoring the closing of a door or other such barrier, such as a sliding door of a vehicle. This system has a circuit outside of the door which serves to emit a signal indicating the open or closed state of the door. In the production of this signal, the need for any electromechanical limit switches or indicating devices mounted on the door and coupled galvanically with the circuit is avoided by providing, in accordance with the invention, a circuit that is mounted on the door. Both circuits have at least one inductive element. The inductive elements are coupled only inductively with one another, but are not in physical contact with one another, so that the production of the signal indicating the open or closed state of the door can be performed contactlessly.

Abstract: In order to perform a vehicle speed control in a motor driven type power steering control device, a speed change point detection sensor is provided and an assist is added or removed according to a speed change point signal therefrom. Therefore, a construction of an input circuit and a control program become simple and a simple control unit can be used. Further, by inputting a speed change point other than those at which the assist is added, it is possible to easily determine a breakage of an input line for speed change point, resulting in a highly safe power steering.

Abstract: According to the present invention, there is provided a device for lifting up and down window glass for a vehicle including a reversible motor for lifting up and down window glass of a vehicle, a drive circuit connected to an input side of the reversible motor, a comparison circuit and/or a control circuit connected to an input side of the drive circuit, a window glass opening degree determination mechanism connected to an input side of the control circuit so as to produce either reference voltage or comparison voltage, a window glass opening degree detector connected to a comparison input of the comparison circuit so as to produce either reference voltage or comparison voltage in accordance with window glass opening degree.

Abstract: The present invention is an automatic garage door operator with a two button portable controller enabling a secure mode and control of a load remote from the door operator. In accordance with the normal operation of the secure button, actuation when the garage door is closed toggles a secure mode between secure and non-secure states. In the secure state the automatic garage door operator does not move the door upon receipt of a door signal. To open the door when in the secure state the operator must first press the secure button to enter the non-secure state and then press the door button to open the door. The secure button has a secondary function when the garage door is open and the secure state is prohibited. Actuation of the secure button when the door is open toggles the state of a load remote from the automatic garage door operator between an on state and an off state. This control is achieved via a signal modulated on the electric power main.

Abstract: In order to provide a seat control which can automatically move a drivers seat and ancillary equipment (e.g. steering wheel) from a set of preselected driving positions to a retracted status in the least disconcerting manner, one of operations (e.g. the steering column tilting operation) is used as a standard for terminating the movement of all of the other movements toward given retracted positions upon the selected operation finishing. Even though the movement of the seat toward its most rearward position may not have been fully completed, the upward tilting of the steering column (viz., the movement incurred with the selected operation) in combination with what rearward movement of the seat has been possible during the tilting, opens up a space sufficient for the driver to easily ingress and egress and positively ensures that all of the various movements terminate simultaneously.

Abstract: One or a plurality of photoelectric detector plates are mounted on a coupling fixed to an arm shaft of a sewing machine, and have predetermined light shields. A light-emitting means is disposed on one side of the photoelectric detector plates for emitting light toward the photoelectric detector plates, and a photodetector means is disposed on the other side of the photoelectric detector plates for receiving the light emitted from the light-emitting means. Conditions of the sewing machine can be detected by the manner in which the photodetector means receives the light.

Abstract: An electric driving device for openable members in which an openable member is opened and closed by rotation of driving shafts provided on right and left sides. The device includes a motor which rotates the driving shafts via a reduction mechanism, and switching relays which switch the rotational direction of the motor. Open and close command switches command the opening and closing of the openable member and a rotation synchronization sensor associated with the motor generates pulses synchronized with the rotation of the motor. A mechanical stopper limits the rotation of the driving shaft which is rotated via the reduction mechanism of the motor and a motor lock detecting means detects locking of the motor by detecting the pulse width generated by the rotation synchronization sensor. Also, an actuation stopping arrangement stops the actuation of an actuation device which supplies current to the motor if a signal is generated by the detection apparatus that detects locking of the motor.

Abstract: In an automobile seat mounted for movement by an electric motor connected between a battery and ground, an improved control system for the motor. There is a power transistor connected in series with the motor. Digital logic is connected for controlling the power transistor. A switch is operably connected for inputting direction control requests for the motor to the digital logic means. Finally, there is a tachometer driven by the motor and having an output connected to the digital logic means for indicating when the motor is moving. The digital logic includes logic for applying a series of pulses of increasing duration to the power transistor when starting the motor to affect a pseudo up ramp power input to the motor and logic for applying a series of pulses of decreasing duration to the power transistor when stopping the motor to affect a pseudo down ramp power input to the motor.

Abstract: A variable electric control controls hydraulic speed control valves. The control includes a reversible DC electric motor coupled to a speed control valve, a detection circuit for detecting the degree to which the valve is opened, and indicator lights for indicating that degree. Electrical limit switches automatically shut off the motor as the valve fully opens or fully closes. A dual-pole, dual-throw actuator switch located at a position remote from the valve controls the electric motor. The indicator lights are located near the actuator switch. The detection circuit, the motor, and the coupling between the valve and the motor are preferably sized and arranged to be positioned on the housing of the valve and, when so positioned, to not extend, in plan, beyond the housing.

Abstract: A control system for a vehicle power seat, which includes at least an electric actuator for powering at least one seat movement and a controller for operating the same. The system includes an electronic control system for detecting operation of the aforementioned controller and connecting the actuator to an electric power supply over wires which, when the actuator is idle, are cut off from the power supply.

Abstract: Variable electrically motorized drive mechanism for gates or similar structure close-off devices that can be installed for the purpose of an assembly operation that is as heavy-duty as possible and without fine adjustments, for which purpose the gate is provided with controls that essentially comprise a position detector, a memory, and a reference-point indicator, the last of which is positioned between the gate-panel limiting positions and outside of any stop positions or defines a corresponding gate-panel reference-point position and synchronizes the position detector at each stroke such that the path that the panel is to travel along from the reference-point position into a particular desired position is dicated or monitored in accordance with a memory output that corresponds to the adjusted position. The system is accordingly continuously self-monitoring and can synchronize itself when the motor is started up again after a power outage and possibly manual operation of the gate.

Abstract: An automatic build-up welding machine for repair of workpieces such as track rollers. The machine requires no operator in charge during the welding operation. The apparatus comprises a device including a pair of guides, and a switch box connected adjustably in position to a welding torch, the switch box housing therein a pair of limit switches for reversing motion of the torch and a swing lever positioned between the limit switches. The apparatus controls the travel of the torch by varying half-cycles of the reciprocable travel thereof.

Abstract: A motor drive control that permits a DC electric motor to be rapidly driven and accurately stopped at predetermined stop positions is disclosed. An indexer (V) generates a deceleration point signal at a deceleration point that occurs before a predetermined stop point of load (VI) and a stop point signal at the stop point corresponding to a predetermined destination of the load (VI). A rotational direction detector (III) detects the rotational direction of the motor (IV) as the motor (IV) passes the stop point and produces a rotational direction signal representing the rotational direction of the motor (IV). A rotation control circuit (I) generates a drive signal in response to movement and movement direction signals; a deceleration direction signal in response to the deceleration point signal; an inhibit signal in response to the stop point signal; and a decelerated drive signal representing a reverse rotational direction of the motor (IV).

Abstract: The present invention is a zoom motor control for controlling an electric motor for use in combination with an auto zoom device for a movie camera. The auto zoom device includes a rotating member driven by the electric motor and a zoom-lens tube rotating member. The zoom motor control includes a rectangular housing which an operator of the movie camera may comfortably hold in his hand and a strain gauge sensor which is mechanically coupled to the rectangular housing. The strain gauge sensor is disposed so that the operator may apply with his thumb a varying amount of pressure in either direction. The strain gauge sensor has an output signal which is proportional to the varying amount of pressure. The zoom motor control includes a control circuit for converting the output signal of the strain gauge sensor to a control signal for controlling the electric motor of the auto zoom device.

Abstract: A linear actuator includes an electric drive motor which is connected to a drive screw through a gear train. Rotation of the drive screw causes the drive nut to move axially in order to impart axial motion to an extension member. Limit switches function to disengage power to the electric motor upon the extension member reaching the outer or inner limits of its stroke. Also, a thermal sensing element located in the windings of the electric motor interrupts power to the motor upon the heat-up of the motor windings above a predetermined temperature, as when the drive nut jams or locks up. A sealed housing contains the drive screw, drive nut and extension to protect against entry of dust. The housing has reaction surfaces which cooperate with the drive nut to permit linear movement of the nut while holding the nut against rotation.

Abstract: This invention relates to a switch for energizing an electric motor of a wiper system from a voltage source, which motor has a switching member to be changed over in several modes of continuous operation as well as in a mode of intermittment operation. The switching member has two bridging contacts of which the first one co-operates with stationary contacts on a first contact path and the second one with stationary contacts on a second contact path. Thereby in at least one switching position a further mode of operation of the wiper system may be switched on via the second bridging contact and the stationary contacts of the associated second contact path in addition to intermittent operation. The switch has thus a high operational reliability, because there is little risk for a simultaneous failure of a stationary contact associated to the same mode of operation on both contact paths.

Abstract: A sensing apparatus for use with an automatic door operator and operator control logic responsive to door control signals for controlling the opening and closing operations of a swinging door is disclosed. The disclosed apparatus includes a plurality of infrared emitters and corresponding detectors on each side of the door which are recessed in the muntin of the door and which direct radiant energy and sense reflected radiant energy in selected detection zones which are determined at various positions of the door. Control logic connected to the detectors generates appropriate door control signals. The control logic is also responsive to door position signals generated by operator control logic to automatically vary the emission and detection levels of the emitters and detectors as the door opens and closes.

Abstract: The present invention is an automatic garage door operator with a two button portable controller enabling a secure mode and control of a load remote from the door operator. In accordance with the normal operation of the secure button, actuation when the garage door is closed toggles a secure mode between secure and non-secure states. In the secure state the automatic gargage door operator does not move the door upon receipt of a door signal. To open the door when in the secure state the operator must first press the secure button to enter the non-secure state and then press the door button to open the door. The secure button has a secondary function when the garage door is open and the secure state is prohibited. Actuation of the secure botton when the door is open toggles the state of a load remote from the automatic garage door operator between an on state and an off state. This control is achieved via a signal modulated on the electric power main.

Abstract: A control apparatus for a sliding vehicle mounted roof panel controls the movement of the sliding roof panel between fully opened and fully closed positions within a window opening in the vehicle and predetermined intermediate, partially opened positions. The control apparatus includes a sensor for detecting the position of the sliding roof panel and a control apparatus, responsive to the output from the sensor, for activating or de-activating the drive motor controlling the movement of the sliding roof panel. A plurality of sensors may be spaced longitudinally along the longitudinal edge of the roof opening to provide a plurality of intermediate, partially opened stop positions for the sliding roof panel between the fully opened and fully closed positions.

Abstract: An apparatus for detecting the position of a seat in a vehicle and position of eye of a sitter on the seat to thereby select an optimal position of a headrest on the basis of the detected position data. A plurality of data representing the seat position and the sitter's eye position are stored in a memory means to be read out for allowing a control means to performs arithmetic operation on the data as read out. On the basis of the result of the arithmetic operation, the positions of the headrests for a plurality of sitters can be selectively determined on the basis of the positions of the seat.

Abstract: A tilt steering mechanism, a telescopic steering mechanism and a seat attitude adjusting mechanism are controlled in their attitudes by an electric motor such that the respective attitudes are automatically set into a retreat attitude where the driver easily gets on and off a vehicle upon boarding/alighting, and into a driving attitude assumed before retreat upon the completion of boarding. Whether or not the driver is about to get on and off the vehicle is judged in accordance with the status of an ignition switch, status of a door switch, vehicle speed, status of a parking brake, shift lever position of a transmission, etc. A change speed of attitude is monitored during energization of the electric motor and, if the change speed is less than a predetermined value, this is judged as the presence of overload and the electric motor is stopped.

Abstract: A plurality of mode switches are electrically connected in parallel to a motor. A conductor plate has a plurality of electric current passages each connected electrically to one of the switches. Each of the passages has a length corresponding to a rotating angle for which the motor is set. A slider is connected to a power source and contacts the passages so that, when one of the switches is closed, the slider may cause an electric current to be supplied to the motor through the passage connected to the closed switch. The slider is slidable along the passages with the rotation of the motor. Each of the passages has a portion at which the contact of the slider therewith is broken so that the supply of the electric current to the motor may be interrupted.

Abstract: An automatic door, driven with a motor and a speed sensor, is controlled with a servo device. Upon the door being opened or closed and being stopped by an obstacle or being out of order, the motor to drive the door will be stopped; in case of the door being retarded by a wind force or other factors, the driving power of the motor will automatically be adjusted to such an extent that the door can still be closed together so as to fully use the driving power of the motor.

Abstract: A power window device has an arrangement to automatically invert the movement direction of a windowpane when an upward movement of the windowpane is prevented in the automatic drive mode by some reason before it reaches its proper upper limit, and also has an arrangement activated to invalidate the automatic inverting function of the arrangement for a predetermined time.

Abstract: A vehicle to loading dock releasable locking unit includes a hook for engaging a coupling on the vehicle, a motorized drive system for rotating the hook back and forth between locked and unlocked positions, and a hook position sensor for sensing whether the hook is in the locked, the unlocked or an unsafe position between the locked and unlocked positions. The automatic control system includes a hook position selector for generating lock or unlock signals in response to a hook position command selected by an operator and for storing the selected hook position command. A first actuator control unit energizes the hook actuator to reposition the hook into the locked position in response to the lock signal. A second actuator control unit energizes the hook actuator to reposition the hook into the unlocked position in response to the unlock signal.

Abstract: A position loop gain control method for deciding the gain of a digital-to-analog converter (301), which constitutes an orientation controller, in such a manner that the gain of a position loop assumes a set value K.sub.p, the position loop being part of a position control feedback system comprising a velocity control circuit (101c), a spindle motor (102), a position coder (104), an orientation controller (101e) and a changeover switch (101b), which method has steps of rotating the spindle motor at a predetermined velocity N.sub.b, measuring a deceleration time T.sub.f taken to achieve deceleration from the velocity N.sub.b down to a velocity of zero, and deciding a gain K.sub.DA of the digital-to-analog converter by using the set value K.sub.p, predetermined velocity Nb, deceleration time T.sub.f, and a distance D from a changeover point, at which there is a transition from velocity control to position control at a time when spindle orientation control is applied, to a prescribed orientation.

Abstract: A device for monitoring the operation of pneumatic seats for vehicles, the seats being supported by a pneumatically-operated spring to give a resilient seat mounting.The monitoring device operates at the commencement of use of the seat and also during use of the seat in case of possible leaks of air.Sensing elements are located at positions above and below a rated central position and are actuated according to movements of the seat from the centralposition. Actuation the sensing elements provides signals for a counter device which when an upper or lower limiting value is reached automatically resets itself to a starting value between the two limiting values and emits a control signal corresponding to the limiting value reached. The control signal operates an air valve for a predetermined length of time to supply air to or discharge air from the pneumatic spring.

Abstract: The present invention relates to a method of leading a moving body, such as a print head carrier of a printer of the like, which is driven by a direct current brushless motor, to a starting position. The direct current brushless motor, which forms part of the present invention, includes a stator including a plurality of armature coils secured on a stator yoke through a substrate, a disk-like magnet having N and S poles arranged alternately in the circumferential direction, the magnet being arranged to confront the armature coils, and a rotatable rotor provided with a speed-detecting slit arranged outside the magnet. Rotating power is obtained by applying an electric current corresponding to the magnetic pole of the magnet to each armature coil.

Abstract: A voltage supply for a servomotor (9) is effected via a wiper (10) which slides on two conductive paths (5, 6) which are displaceable in longitudinal direction. The conductive paths (5, 6) have, at their opposite ends, a driver (15, 17) against which the wiper (10) can come in its end positions upon further displacement, in order to be able to carry the corresponding conductive path (5, 6) along with it. Directly before the driver (15, 17) is reached, no voltage is tapped off from the corresponding conductive path (5, 6), so that the servomotor (9) then stops.

Abstract: An actuating device for automatically controlling the position of a movably mounted vehicle mirror comprises a motor controlled by switches for selectively actuating the motor in response to angular displacement of a trailer with respect to the vehicle. The switches are actuated in response to movement of the trailer and responsively close a circuit connecting a power source to the motor. Preferably, the switching means can include means for disconnecting the power source after a predetermined rotation of the motor in order to avoid excess energy use. Preferably, the disconnecting means comprises a plurality of switches arranged to contact lobes of a rotating cam at predetermined rotational positions of the cam. The cam can be concentrically secured to the rotor shaft or can be connected to the rotor shaft by a lever mechanism in order to form a crank which translates the rotor movement to linear displacement on a mirror positioning member.

Abstract: In a grinder, the table carrying the workpiece to be ground reciprocates to carry it past a grinding wheel. The table moves armatures oppositely into and out of respective coils, inducting voltage therein for driving the reversible motor that moves the table. Remote coils with manually settable armatures therein oppose the first coils for determining the range of movement of the table. A control circuit includes right and left halves corresponding to the directions of movement of the table. Right and left SCR's control the current from first coils to the drive motor, transistors control the gating current to the SCR's; triacs control the current from the transistors, and other triacs control the current from the main source to the drive motor.

Abstract: A retractable motor-driven antenna 10 of compact size and light weight capable of being supported at the top of a support tube 14. A molded plastic housing 12, 30 in part forms the drive motor. A drive transmission 34 for extending and retracting the antenna mast 15 uses a timing belt 78 and pulley wheels 61, 62 and includes an overrunning clutch 84 or energy storage and release interconnection 76 between a drive pulley wheel 261 and a motor output shaft that drives a flexible cord 46 connected to the antenna mast. A switch assembly within the housing includes automatically stops the drive when the mast reaches its extended or retracted position or is obstructed. A coupling between the molded plastic housing and an antenna support tube isolates the housing from road vibration.

Abstract: An object sensing apparatus includes a plurality of light emitting diodes for illuminating a region of space and a plurality of closely arranged light detectors for receiving light reflected from an object. The apparatus is particularly useful in connection with automatically operated doors.

Abstract: A plurality of photoelectric detector plates are mounted in successive layers on a coupling secured to a sewing machine arm shaft, and have light shields disposed concentrically so as not to be overlapped. Light-emitting means is arranged on one side of the photoelectric detector plates for emitting light toward the latter, and photodetector means is positioned on the other side of the photoelectric detector plates for receiving the light from the light-emitting means. Conditions of the sewing machine can be detected by the manner in which the photodetector means receives the light. The photoelectric detector plates are pressed axially of the coupling and adjustable into given angular positons, respectively, with respect to the coupling.

Abstract: An electronic landing device for controlling the movement of an elevator car during the final several inches of travel approaching a floor. The device provides a smooth transition from run (deceleration) mode to landing mode within a wide range of speeds at the transfer point. A digital computation is performed on a speed signal generated at the transfer point, to provide optimum time-to-landing and decelaration profile during the landing mode.

Abstract: A multiposition controller includes a first switching element for switching on and off in accordance with a position of a movable object to be controlled and a second switching element for detecting the direction of movement of the object. The second switching element switches off when the object is positioned at one side from an initial position of the object, while it switches on when the object is positioned at the other side from the initial position of the object. Furthermore, the second switching element remains off or on when the object is positioned at the initial position. By such a simple structure, an accurate position control can be achieved.

Abstract: Apparatus for electrically controlling actuation and deactuation of a hydraulic fluid directional control valve between centered, forwardly-moved and reversely-moved positions thereof includes a reversible electric motor whose drive train is connected to the valve control member for forward and reverse rotation thereof and an arrangement of two forward and two reverse electric circuits between an electrical source and the motor, two manual switches each in associated forward and reverse circuits, four limit switches positioned each in one circuit, and cams mounted on the motor drive train to open and close the limit switches in relation to the rotational disposition of the drive train to provide for manual actuation by the manual switches of selected forward and reverse rotation of the motor drive train and valve control member, for automatic deactuation of the electric motor by the limit switches at each of the two predetermined rotated dispositions of the valve member, for selective holding of the valve mem

Abstract: An improvement for a controller (C) for controlling the idle speed of an engine. A logic circuit (1) is responsive to the position of switches (S1, S2) and the direction in which an extendible and retractable member (T) is to be driven by a motor (M) to energize the motor. The logic circuit includes logic gate (3) responsive to both switches being open when the member is at its extreme extended position and the member is to be retracted to energize the motor to retract the member. The logic circuit also includes a logic gate (5) responsive to both the switches being open when the member is at its extreme retracted position and the member is to be extended to energize the motor to extend the member. The motor is thus energized to move the member in the appropriate direction even though a switch which should be closed is open due to dust or debris preventing switch closure.

Abstract: A machine tool for working sheet metal is described. The principal characteristic of the present invention lies in the fact that it comprises electronic apparatus operable to control the adjustment of the stroke of a striker which can strike a pin supporting a tool for punching or nibbling a metal sheet.

Abstract: A microprocessor based control system for establishing the optimum points of motor turn on and turn off for an oscillatory pumping system. The power to the motor is disabled at a point calculated to return the maximum stored mechanical energy to the system after turn-around. The motor is restarted at either a predetermined motor speed which may be different in the up and down stroke directions, or when the speed peaks. Safeguards are also provided under control of the microprocessor for disabling pump operation in the event of pump overtravel, overload or pump off. The control permits dynamic changes to the operating parameters of the pumping system in order to optimize the power required by the motor over a wide range of operating conditions.

Abstract: A commutator-type d-c motor has its line current connected through a sensing resistor (18) or transformer (18'), the pulses of which, upon energization, are counted in a counter (C) and also passed to a speed sensing circuit (S) in a control circuit (30), energization of the motor being disconnected if the frequency of undulations or waviness of the motor current drops, thus indicating that the positioned element, for example an antenna, window, or sliding roof of an automobile has reached a limiting position. The counter can be used to establish intermediate positions, upon suitable control by a selector switch (27) or a reference count number stage (C-Ref) controlled, for example, by a potentiometer (P) or from the selector switch (27). A timing circuit (T) prevents short-circuit through the motor upon manual sudden reversal of command of direction of rotation.

Abstract: Proximity detector circuitry of particular value in controlling the operation of elevator car doors. Sensors are set in the edge of the door. The outputs of the sensors are fed to one or more differential amplifiers which produce outputs dependent on the sensors. One such output may be compared in a further differential amplifier with its previous output slightly delayed in time and the results of the comparison used to actuate a door closing/opening control circuit. In addition large outputs arising from major differences in the sensors output may be fed (suitably attenuated) to the closing/opening control circuit.

Abstract: A solid state circuit for sequencing a valve mechanism from its normal operating position through a sequence of cycles to blow down various different lines of the network to which the valve mechanism is connected. The circuit may be set to initiate its sequence at one of a number of time periods such as once a day or once a week. Once initiated, the circuit operates a motor drive for the valve mechanism continuing for a timed interval followed by a delay or dwell at each blow down position. A signal is provided to indicate that the circuit is about to enter a blow down sequence followed by the sequence itself. Various alarms and safeguards are provided for the sequence.

Abstract: A needle position detector for a sewing machine includes a pair of disk-like members axially mounted on a rotary shaft coupled to the armshaft of the sewing machine. Each of the disk-like members is provided with an optically nonreflective portion occupying a greater area of its circumference and an optically reflective portion occupying a smaller area of the circumference. The disk-like members are adjusted so that the angular positions of the respective reflective portions correspond to the upper and lower needle positions. A light emitting element is associated with each of the disk-like members to emit light in a radial direction thereto. A light sensitive element is also associated with each disk-like member to receive light reflected from the reflective portion of the associated disk-like member to generate a needle position signal.

Abstract: An induction type positioning system which accurately stops a movable part without a contact and holds it in the stopped position without depending on the friction force of mechanical contact is disclosed. A primary core consisting of a main pole, an auxiliary pole, and a single phase AC magnetic field generation coil, and a conductive plate which moves relative to this primary core, generate a holding force for suppressing the relative movement between the primary core and the conductive plate by use of the eddy current which is induced on the conductive plate by the field generated by the main pole at the position where the conductive plate is placed on the auxiliary pole and simultaneously the edge of the conductive plate is placed on the main pole, and by use of the eddy current which is induced on the conductive plate by the field generated from the auxiliary pole.

Abstract: A security timer for a powered overhead garage door causes the garage door to close after it has been opened for a selected time interval. The security timer includes an oscillator that provides pulses. A counter counts the pulses and provides a binary output. A timer switch is engaged by the door when the door is fully open. Engagement of the timer switch signals the oscillator and counter to begin. When the desired number of pulses has been counted, a relay switch is closed for signaling the operator unit of the door to close the door.

Abstract: A power screwdriver that is equipped with a spring coupling between the motor drive and the tool spindle, a signal that indicates that a certain value of torque has been overstepped, at which the screwdriver must be sopped, first causes reversal of the motor, but before the motor appreciably turns in the reverse direction, powers shut-off, allowing the motor to coast. After another brief interval, power is reapplied to the motor in the original direction, again briefly. In this way it is possible for the final shut-off to occur when the motor is stopped and the spring is unstressed, avoiding oscillations of the motor-spring system. A triac bridge circuit makes possible quick reversals and brief applications of power. In such a bridge circuit, precautions must be taken to be sure one pair of triacs is extinguished before the other pair is ignited.

Abstract: An improvement in door activating control apparatus including a short delay between the time the door is stopped during its closing direction of travel and starts moving in the opening direction when any one of any switch or button for opening the door is activated, prevents the stress incurred when the door is required to instantly reverse its direction of travel while closing, demonstrates a distinct advantage especially when controlling large heavy doors, or for door openings that require a high volume of traffic and in emergency situations, includes a means to by-pass the delayed reversing when the door is in the closed position. Features a novel means of using a single pole double throw switch which will serve to defeat a safety edge device and by-pass the delayed reversing, embodied in a single enclosure along with the door closing limit switch, all actuated by a single mechanical actuating device at the door closed position, demonstrates distinct advantages in door operator design.

Abstract: Apparatus for an electrically moved sliding window used in automotive applications, having a built-in safety device is described. This detector is a proximity detector which detects the approach of a portion of a human body, e.g. a gloved hand. This detector is advantageously comprised of a capacitive pickup carried along the upper edges of the window, connected to a detector stage which, as a function of the rate of change in the signal appearing across the pickup, acts, via an amplifier, to remove the electrical power supplied to the drive motor of the window.

Abstract: An apparatus is provided for accurately moving a body in accordance with a predetermined motion. An embodiment of the invention relates to an optical scanning system in which the movement of an intermittently tilting mirror is required to be extremely linear. The positions of the mirror at predetermined points are compared with the required positions and correction signals generated for use on subsequent movement cycles. Because of the high speed of movement of the mirror, it is preferred to make only one comparison per movement cycle and it may be necessary for a number of comparisons to be made for any one predetermined point until a satisfactory correction is achieved.