Abstract: An air-cooled eddy current dynamometer for the use in a vehicle emissions test stand application. The dynamometer housing includes an air inlet manifold for drawing cooling air radially inwardly into the dynamometer and an air outlet manifold permitting the expulsion of heated air tangentially outwardly from the dynamometer. An end of the dynamometer housing has a plurality of openings therein allowing cooling air to be drawn axially inwardly into the dynamometer housing. The combination of air flows radially inwardly through the inlet manifold, axially inwardly through the openings in the end of the dynamometer and tangentially outwardly through the outlet manifold significantly increases the cooling of the dynamometer permitting its use in a vehicle test stand application wherein the dynamometer is placed in a recess or pit within the floor of the structure in which the test stand is installed.

Abstract: An amplitude-control system for a signal generator corrects for variations that occur in the amplitude of output signal upon changing of the specified frequency. It also corrects for errors that occur (due to non-linearity) in the amplitude of its output signal upon changing of the specified amplitude. The amplitude-control system performs both of the amplitude corrections simultaneously and very rapidly by means of an arrangement that employs mostly hardware and very little software. Look-up tables that are stored in memories are read directly instead of by a CPU, and a resulting control signal sets the gain of an amplifier that has voltage-controllable gain. The amplifier amplifies the uncorrected output of the signal generator so as to provide an output signal of corrected amplitude. Calibration is accomplished by automatically or semi-automatically by loading correction data into the memories to form look-up tables.

Abstract: A fluid operated coupling which includes an inflatable annular tube element of an elastomeric material moves a plurality of aligned friction shoes in a radial direction to effect a torque sustaining clutching or braking engagement. A thermal barrier is provided to retard the transfer of heat from the friction shoes to the annular tube element. The thermal barrier protects the tube element and adds mechanical strength thereto to prevent excessive elongation and extrusion of the tube element between the plurality of friction shoes when the tube element is expanded. The thermal barrier is at least partially imbedded in the exterior surface of the tube element.

Abstract: A motor control for controlling current in an induction motor. A microcomputer generates three inputs to control an inverter circuit that energizes the three phase windings of the motor. A speed control modulates the three inputs to adjust motor speed and voltage. A current sensing circuit also modulates the three inputs to reduce motor current using a technique that over rides the speed control. By monitoring the current sensing circuit the microcomputer adjusts the speed control to force motor current to a level near a set threshold value.

Abstract: A disc brake or clutch unit (10) comprising a rotor disc (12) having a fixed reaction member (21,23) on each side of the rotor disc (12) with the reaction members fixed in axially spaced relationship by connecting members (24,25) extending axially in position radially outwardly from the rotor disc. A pair of moveable reaction members (27,28) positioned between each side of the rotor disc (12) and one of the second fixed reaction members with the relatively moveable annular reaction members connected to each other a fixed axial distance apart by connecting members (29,30) extending axially and positioned radially outwardly from the rotor disc (12). Springs (35) are positioned between a first axially moveable reaction member (27) and a relatively fixed reaction member (23) for biasing the moveable reaction member (27) into fictional engagement with the disc (12).

Abstract: A clutch and brake assembly which includes a spring applied brake and a fluid applied clutch which is adapted to rapidly cycle. A fluid circuit is provided for rapidly pressurizing and rapidly depressurizing the apparatus. The fluid circuit includes a manifold having a main fluid passageway and a plurality of secondary fluid passageways disposed therein. Each of the secondary fluid passageways includes a quick release exhaust valve which is operable to rapidly exhaust fluid from the apparatus to allow the brake to rapidly engage when the fluid pressure in the main fluid passage way and secondary passageway decreases to less than the fluid pressure in the pressure chamber.

Abstract: A disc brake or clutch assembly having rotatable rotor discs and non-rotatable discs which are movable axially into engagement. The rotatable rotor discs are secured to an annular splined mounting member which has a plurality of grooves therein to circulate cooling air. The rotor discs have a plurality of holes which enable air to flow between the rotor discs.

Abstract: An eddy current brake for braking the rotation of a rotating shaft driven by a drive including a rotatable, stamped one-piece inductor drum member connectable to a driven shaft, having a radially extending portion and an axially extending portion spaced from and substantially parallel to the axis of rotation of the driven shaft. A pole assembly is located within a volume defined by said drum member and is rigidly attached to an end adaptor plate of the drive. The pole assembly includes a pair of stamped pole members each defining a plurality of poles which are placed in a confronting, interdigitated relationship upon assembly.

Abstract: Method and apparatus for determining a frequency of a series of signals. A pulse train whose frequency is to be measured is counted. The time that the counting takes place is varied to coincide with the occurrence of a beginning and an ending pulse. The pulse count is then divided by the time to give the measured frequency in hertz. The system is useful in a tachometer motor controller system.

Abstract: An eddy current coupling for a dynamo-electric machine. A flux path between a rotating drive shaft and a rotatable driven shaft includes an inductor drum connected to the drive shaft and a pole assembly coupled to the driven shaft. A coil assembly partially surrounded by the pole assembly controls the degree of electromagnetic coupling. A series of interdigitated pole fingers are spaced between the inductor drum and the field coil assembly to facilitate air flow that dissipates heat caused by relative rotation between the inductor drum and the pole assembly. The coil assembly includes an annular coil support co-axial with the driven shaft to support an annular field coil in a gap defined by the pole assembly.

Abstract: An interface for generating a serial bit stream corresponding to one or more switch settings and transmitting that bit stream to a polling circuit. Four parallel bits representing a setting of a decimal switch are converted to serial bit sequence. This sequence is preceded by a start bit and followed by an extended stop bit. In an embodiment where multiple switches are polled, the data sequence is followed by a switch designating sequence and then the extended stop bit.

Abstract: A low cost, linear, low impedance tachometer/generator includes a stator and a rotor. The rotor includes a plurality of magnetic poles which alternate between first and second polarities, and the stator includes a plurality of first and second annular sets of planar laminated poles which are spaced apart, with the first set of poles having a first polarity and the second set of poles having a second polarity. An annular coil is disposed between the first and second sets of poles. The first set of poles is axially spaced apart and circumferentially offset one pole pitch about the axis of rotation from the second set of poles to effect simultaneous periodic alignment of the first set of poles on the stator with the plurality of poles on the rotor of the second polarity and the second set of poles on the stator with the plurality of poles on the rotor of the first polarity.

Abstract: A drive apparatus for a printer mechanism including a printhead comprises first and second print medium drive means for feeding first and second print mediums past the printhead, a main drive gear rotatable in a first direction for driving the first print medium drive means and rotatable in a second direction for driving the second print medium drive means, selectively engageable drive means alternately engageable with the first and second print medium drive means for driving the first print medium drive means in a first direction when the main drive gear is rotated in the first direction and driving the second print medium drive means in a second direction when the main drive gear is rotated in the second direction and locking means for locking the first print medium drive means when the main drive gear is rotated in the second direction.

Abstract: A printing apparatus including a feed path for print medium to be imprinted. A printing station defined by a printhead that is biased towards abutting contact with a platen roller. A floating mount pivotally mounts the printhead with respect to the platen roller so that a uniform contact pressure is established between the printhead and print medium during printing. The printhead is also mounted for pivotal movement about an axis transverse to the first axis which allows the printhead to move towards and away from the platen roller to facilitate loading of the print medium. A printhead sensor monitors the position of the head and automatically deactivates the printhead when it is about to be, or is separated, from the platen roller. A stripper mechanism is provided for automatically stripping a backing from the print medium and includes a stripper assist bar that causes the backing to follow, and frictionally engage, a peripheral region on the platen roller that is at least 90.degree..

Abstract: A new method and apparatus for controlling the conversion of AC electrical energy into DC electrical energy. A microprocessor control system is operatively connected to an AC source and to a motor/regenerative switching bridge network. A control signal is operatively coupled to the microprocessor to selectively adjust the DC output voltage. The microprocessor monitors the control voltage, calculates the timing of gating signals and generates gating pulses to the bridge networks. The microprocessor also senses the phase rotation and the line frequency of the AC source and factors those parameters into account when determining gate pulse output pattern and timing.

Abstract: A method of monitoring the performance of a tool which moves relative to a workpiece through a cycle and controlling the feed rate between the tool and the workpiece includes the steps of dividing the cycle into a plurality of increments, sensing a function of force applied to the tool during the increments, determining a mathematically smoothed function of force for the function of force for each sensed individual increment of the cycle and establishing a reference for the mathematically smoothed function of force for each of the sensed increments. The actual determined sensed mathematically smoothed function of force for a particular increment is compared with the established reference for that particular increment and a first signal is generated if the actual determined mathematically smoothed function of force deviates from the established reference. The feed rate between the tool and workpiece is modified in dependence upon the first signal.

Abstract: A method of monitoring the performance of a cutting tool which moves relative to a workpiece through a cycle includes the steps of dividing the cycle into a plurality of increments, sensing a function of force applied to the tool during the increments, mathematically smoothing the function of force sensed during the increments, and establishing a trend in the mathematically smoothed function of force for the plurality of increments. The mathematically smoothed function of force is compared with the established trend and if the mathematically smoothed function of force deviates substantially from the established trend a first signal is generated.

Abstract: An optical inspection system (10) for deriving information from an item (12) to be inspected includes a light source (14), an optical reader (16) responsive to the light reflected from the inspected item for deriving an analog signal (83) indicative of information sensed on the inspected item, a threshold circuit (24) for setting a dynamic threshold used to convert the analog signal into a binary signal (144) indicative of the information sensed on the inspected item. The threshold circuit includes a high peak detector (100) and a low peak detector (102) responsive, respectively, to the highest peak and to the lowest peak in said analog signal for generating a high and low signal, respectively, indicative thereof. A threshold setting circuit (132) is responsive to the high signal and the low signal to set a threshold therebetween. A comparator (22) compares the analog signal with the set threshold and converts the analog signal to a binary signal indicative of the information sensed on the inspected item.

Abstract: A method of monitoring the performance of a cutting tool which moves relative to a workpiece through a cycle including the steps of dividing the cycle into a plurality of increments, sensing the function of force applied to the tool during each of the increments, determining and storing the highest function of force and lowest function of force applied to the workpiece during each of the increments, setting a maximum differential function of force limit, calculating the difference between the highest and lowest function of force sensed during each increment and comparing the calculated function of force differential with the set maximum function of force differential and establishing a signal when the calculated function of force differential exceeds the set maximum differential. In the preferred embodiment, the function of force is torque.

Abstract: A printer apparatus including a printhead (14) for printing on a data carrier (20), a printhead carrier (15) for moving the printhead along a path, a cutter mechanism (30) for cutting the data carrier upon command, a bi-directional drive means (34) having an output shaft (36) operable to be driven in first and second directions and a one-way clutch means (46) operatively associated with the output shaft for actuating the cutter mechanism (30) and driving the printhead carrier (14). The drive means when effecting rotation of the output shaft (36) in the first direction effecting movement of the printhead carrier and printhead along the path and when effecting rotation of the output shaft in the second direction effecting actuation of the cutter mechanism (30) to cut the data carrier.