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Felix Hoffmann, a German chemist, was searching for something to relieve his father's arthritis. In doing so, he "rediscovered" acetylsalicylic acid and in 1900, patented a stable process for developing it. Hence, we have aspirin.
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| Number | Title | Issue Date |
| 4699524 | Supplementary cooling system for thrust bearing Apparatus for providing supplementary cooling to the thrust bearing of a vertical shaft machine, without requiring an additional exterior pump and motor, has an oil conducting path formed by grooves in the engaging surfaces of an upper and a lower portion... | 10/13/1987 |
| 4657411 | Hydraulically supported thrust bearings A thrust bearing particularly suitable for use with a vertical shaft machine has a rotating ring mounted to the shaft for rotation with the shaft and having a downwardly directed bearing surface. A base ring is positioned around the shaft and fixedly moun... | 04/14/1987 |
| 4635769 | Gear protection system for grinding mills A clutch is interposed between the driving gears of a grinding mill and the driving motor to protect the gears from damage by mechanical overloading. The clutch is set to slip at torques below those required to structurally damage the gears yet higher tha... | 01/13/1987 |
| 4636910 | Varistor overvoltage protection system with temperature systems A system having a bus protected against overvoltage by a plurality of series connected zinc oxide varistors in a column, uses temperature sensors to protect the varistors from damage. First temperature sensors detect that a safety tripping temperature has... | 01/13/1987 |
| 4594880 | Apparatus for determining finished roll density in a mill In the prior art it is known to determine the density of a roll of paper as it is being wound on a paper receiving roll. The determination is made each time the paper receiving roll makes a constant predetermined number of revolutions. Because the diamete... | 06/17/1986 |
| 4573132 | Thermal model for electrical apparatus A thermal model of an electric apparatus such as a transformer or motor, from which signals can be obtained representing temperatures of the conductors and of the adjacent core material, includes storing first and second values, respectively, representing... | 02/25/1986 |
| 4572978 | Commutator stud vibration damping arrangement In a commutator formed by a plurality of commutator bars clamped between an annular shell and a clamping ring held together by studs, the life of the commutator may be extended significantly by imposing a resilient damper between the stud and the inside w... | 02/25/1986 |
| 4556830 | Speed controller for mill drives and the like A speed controller for a mill drive has two control portions. The first control portion has a first speed of response for controlling mill speed during normal operation. The second control portion has a second speed of response, faster than the first spee... | 12/03/1985 |
| 4556826 | Inching supply torque control In a drive system for a grinding mill the load torque plus frictional torque may increase considerably as a loaded mill is inched from its rest position and will suddenly decrease when the load tumbles or cascades. The applied torque or driving torque mus... | 12/03/1985 |
| 4538202 | Current transformer secondary voltage limiter A device for protecting the secondary winding of a current transformer against destructive or dangerous overvoltages when connected across the secondary, has a transparent tubular casing with a stud support and conductive stud within one end. The stud is ... | 08/27/1985 |
| 4520910 | Grinding mill control using controlled pulsing of air clutches There is provided a control apparatus for stopping a large grinding mill driven by two synchronous motors coupled to the mill through respective air clutches. The control includes a clutch actuator control which applies a predetermined amount of pressure ... | 06/04/1985 |
| 4496883 | Electric inching impulse control There is provided an electrical inching control for inching a drive system comprising a grinding mill driven by one or more three phase synchronous motors. The electric inching control includes an inching power bus and contactors or the solid state equiva... | 01/29/1985 |
| 4491767 | Synchronizing synchronous motors, motors prior to clutch closure In the inching of a grinding mill or similar apparatus which is driven by a pair of synchronous motors through fluid actuated clutches, the motors must be angularly alined one with the other in order that the load be shared equally between the motors. The... | 01/01/1985 |
| 4475139 | Thyristor-switched capacitor apparatus A protective circuit for a plurality of series connected thyristors where each thyristor has in parallel with it a resistance, capacitance type snubber circuit and a metal oxide varistor. The arrangement of the series connected thyristors, snubber circuit... | 10/02/1984 |
| 4451870 | Capacitive signal coupler A capacitive signal coupler for use with a large dynamoelectric machine for coupling signals indicative of corona discharge from the stator bars to a monitor system is combined with an end cap made to fit over the connector extending between two stator ba... | 05/29/1984 |
| 4447739 | Rotor withdrawal arrangement for bulb generators Apparatus for withdrawing the rotor from the stator in a bulb-type generator makes the rotor and the inner portion of the stator accessible for repair or maintenance without having to disassemble the housing and stator. A pair of detachable beams are plac... | 05/08/1984 |
| 4422320 | Wedge tightness measuring device A device for determining the tightness of a wedge used to close the slot of a dynamoelectric machine and firmly restrain the conductors installed in the slot, is in the form of a tapping hammer or similar tapping tool. The heat of the hammer contains an a... | 12/27/1983 |
| 4420996 | Slitter indexing system A paper slitter machine having a plurality of slitter heads in mutually spaced apart relation located across the width of the machine, each slitter head having a slitter disc operable in cooperating relation with a respective annular disc or slitter band ... | 12/20/1983 |
| 4422022 | Speed control for truck A speed control for a DC motor drive having regenerative braking and a field reversing control, has a field current feedback circuit which includes a modifier to change the feedback signal in accordance with the saturation curve of the field to provide a ... | 12/20/1983 |
| 4420809 | Frequency determining apparatus A frequency determining apparatus for receiving an input signal of unknown frequency and providing an output signal representing the frequency where the output signal is updated at substantially regular intervals regardless of the frequency of the input s... | 12/13/1983 |
| 4373556 | Cut-out fuse tube The present invention concerns the use of polyester materials in arc quenching applications, particularly in the cutout fuse tube industry. In one embodiment of the present invention a fuse tube is disclosed as comprising a laminate two-layered structure ... | 02/15/1983 |
| 4373555 | Cut-out fuse tube The present invention concerns improvements in the use of polyester materials in arc quenching applications, particularly in the cutout fuse tube industry. In one embodiment of the present invention a fuse tube is disclosed as comprising a laminate two-la... | 02/15/1983 |
| 4364171 | Method for fabricating isolated phase bus The method includes aligning a first plurality of cylindrical workpieces of a first diameter such that the longitudinal axes thereof are substantially coincident and welding the workpieces together end-to-end to form a cylindrical member of a desired leng... | 12/21/1982 |
| 4353108 | Frame assembly for electronic components The present invention provides a dielectric paper frame structure suitable for use in a shell-type housing for supporting a small number of discrete electronic components in spaced-apart, non-contacting and electrically insulating relation from the walls ... | 10/05/1982 |
| 4345123 | Self-adjusting brake engine limit switch assembly The self-adjusting limit switch assembly of this invention has two switches mounted on a slide for sliding movement on a bracket. A transverse slot in the slide has two facing surfaces. The switches are mounted on each side of the slot with their operatin... | 08/17/1982 |
| 4322668 | Power control of a stalling motor A control system, for a motor which may be subjected to stalling loads, provides a non-linear increase in motor current during stalling conditions to maintain rated horsepower. When the maximum transient overload current is reached, this current is mainta... | 03/30/1982 |
| 4318268 | Mulching lawn mower A chuteless rotary scything mulching lawn mower is described which is particularly adapted to be powered by an electric motor including sealed motors. The cutting chamber includes a toroidal portion bounded by concentric skirt walls wherein the cross sect... | 03/09/1982 |
| 4316771 | Nuclear fuel stress corrosion prevention Nuclear fuel for use in nuclear reactors is provided in the form of a nuclear fuel element with an interior barrier layer interposed between the sheath and the fuel. The barrier layer incorporates particles of copper in finely divided form to provide by c... | 02/23/1982 |
| 4310748 | Electric kettle reservoir assembly A reservoir for an electric kettle is defined by a dome shaped shell and a planar inner bottom, which are fastened together mechanically having a room temperature vulcanized silicone rubber filler located therebetween to act as a seal. The shell is skirte... | 01/12/1982 |
| 4306404 | Rectifier assembly for a lawn mower An electric lawn mower having a permanent magnet motor and a dynamic braking feature includes a rectifier which is assembled in a switch-box. The novel arrangement of the rectifier in the switch-box assembly is attached to an upper portion of the handle o... | 12/22/1981 |
| 4297305 | Nuclear fuel recycling system In the processes of nuclear fuel manufacture, scrap material such as uncontaminated reject powder and reject pellets, which would previously have been reprocessed chemially in conversion of the uranium values by dissolution into liquid form, is now mechan... | 10/27/1981 |
| 4291263 | Amortisseur winding protection system This invention relates to a system for protecting an amortisseur winding during the starting of a synchronous motor. The system compares the actual slip frequency of the accelerating motor with predetermined slip frequencies. These predetermined slip freq... | 09/22/1981 |
| 4291360 | Remote control wiring system A remote control wiring system is provided with a transformer that supplies a low voltage signal to a low voltage sub-system. The sub-system includes a diode circuit comprising four diodes which permit energization of a first set of relays on a positive p... | 09/22/1981 |
| 4265325 | Percussion rock bit In a percussive rock bit or similar tool wherein cemented carbide cutting inserts are retained in open radial slots in the head of the tool, an improved method of mechanically retaining the inserts. The inserts are provided with a plurality of elongated r... | 05/05/1981 |
| 4253080 | Fuse with helical fuse element A current limiting fuse has a helically coiled fuse element of ribbon-like material extending within a tubular casing between metallic end caps. The ribbon-like material is edge on to the axis of the helix for permitting a greater length of fuse element t... | 02/24/1981 |
| 4244164 | Safety lawn mower and grass collector A rotary blade lawn mower has a grass collecting bin secured to the deck thereof, preferably wholly within the wheelbase of the lawn mower. A squirrel tail duct transfers grass cuttings from the cutting chamber to the bin. The elbow portion of the duct hi... | 01/13/1981 |
| 4238810 | Forced commutation precipitator circuit A control circuit for an electrical precipitator having a high voltage transformer with a bridge rectifier between the secondary of the transformer and the high voltage precipitator electrodes. The control circuit includes a pair of oppositely poled main ... | 12/09/1980 |
| 4238733 | Corona discharge monitor system A corona discharge monitor system for a dynamoelectric machine, particularly for large salient pole generators, has an antenna mounted on a rotor pole. The antenna sweeps over the stator slots and picks up radio frequency signals produced by corona activi... | 12/09/1980 |
| 4238750 | Mechanical trip device for a circuit breaker In a power circuit breaker a trip mechanism is provided normally to oppose the large opening forces associated with the separable contacts of the breaker and to hold the contacts closed. The trip mechanism in response to overload current conditions collap... | 12/09/1980 |
| 4208570 | Thermostatically controlled electric engine coolant heater An automobile engine coolant heater for connection to hoses of the engine coolant systems has a elongated cylindrical jacket portion defining a coolant flow path from an inlet at one end to an outlet at the other end. A metal sheathed heating element is l... | 06/17/1980 |
