Did You Know...
...that the inventor of the electric motor was a blacksmith named Thomas Davenport? Described as "a brilliantly unsuccessful inventor", Davenport invented the first rotary electric motor. In 1836 he headed out -- on foot -- from his Vermont home to file a patent application at the Patent Office in Washington, D.C. By the time he got there, he had squandered away his money and couldn't afford the $30 filing fee so he turned around and went home. When he later mailed in his application with money he'd raised, the Patent office was destroyed in a fire. He did finally get credit for his invention on Feb. 5, 1837.
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| Number | Title | Issue Date |
| 4063057 | Temperature compensated pressure differential sensing devices, including improved press-to-test and glass header switch mounting A pressure differential sensing device comprises a sealed housing having mounted therein a gas-filled flexible capsule and a switch operated by expansion of the capsule. The pressure differential sensing device is mounted to a pressurized chamber with the... | 12/13/1977 |
| 4059087 | Oil pressure detecting apparatus for internal combustion engines An oil pressure detecting apparatus for an internal combustion engine comprises an LC oscillator having an inductance variable in dependence upon variation in the oil pressure of the engine. The frequency or voltage of an output signal of the oscillator i... | 11/22/1977 |
| 4057783 | Device for transmitting the condition of a switch between two parts in relative rotary movement A device for transmitting the condition of a switch comprising a first assembly consisting of a switch, a first pair of coils serially connected when the switch is closed, and a second assembly consisting of a second pair of coils, magnetically coupled to... | 11/08/1977 |
| 4055844 | Detection system A static fluid system for detecting a selected change in an ambient condition. The system includes an elongate closed fluid line having a selected absolute pressure and pressure means to maintain the line pressure. Sensing means in the line respond to sel... | 10/25/1977 |
| 4051920 | Method and apparatus for vacuum evacuation and pressure fillings of sealed pin joints An apparatus and method for vacuum evacuation and pressure filling of a lubricant reservoir are provided which includes a sequence timing and shutoff mechanism for controlling evacuation, testing for air leaks, and filling with lubricant. Visual indicatio... | 10/04/1977 |
| 4050458 | Respiration system with patient assist capability A method and apparatus for initiating a positive-pressure-assisted inspiration phase in response to a patient's inspiratory effort, and independently of the absolute pressure at the time of the inspiratory effort, since the absolute pressure may vary from... | 09/27/1977 |
| 4049935 | Pressure switch with diaphragm A pressure switch for use within a pressure chamber containing a gas having a pressure of P2, said switch including a pressure vessel containing gas having a pressure of P1, said vessel circumscribed by an end wall at one end thereof... | 09/20/1977 |
| 4040042 | Exhaust apparatus and monitoring circuit therefor The present exhaust apparatus has a housing with a tiltable front wall and a tiltable bottom wall. The front wall carries the fan unit proper with its drive motor and filter and the tiltable bottom wall may be provided with a light. In order to monitor th... | 08/02/1977 |
| 4037192 | Flat tire indicating device An air-operated switch device is provided in a housing having an internally threaded part threadedly coupled to the valve stem of a tire. The switch device is in operative proximity with the valve stem and has an open condition when the tire pressure is a... | 07/19/1977 |
| 4020482 | Patient monitor An elongated air inflated flexible bag is placed below the mattress of a hospital or nursing home bed and connected to a pressure actuated electrical switch signal at a remote attendant's station. The switch is a normally closed low pressure switch that r... | 04/26/1977 |
| 4008619 | Vacuum monitoring Monitoring of gas contamination and of related deviations in pressures within a sealed cavity is effected by way of electrical-network responses to conduction characteristics of a thin-film deposit of getter material within the cavity, the getter film bei... | 02/22/1977 |
| 4006472 | Aircraft altitude alerting device The drive for the indicator mechanism of an altimeter is connected so as to drive altitude marker means, the relative position of such marker means being indicative of altitude. The marker means has a marker which may be implemented by a slot formed there... | 02/01/1977 |
| 4004270 | Electronic tire pressure alarm circuitry An electronic alarm circuit indicates an abnormal pressure condition in a pneumatic tire on a vehicle. The circuit includes an indicator, either in the form of a light or sound buzzer, or both, which can transmit two distinguishable signals, one indicatin... | 01/18/1977 |
| 3997887 | Piston overtravel indicator A pressure converter for converting and intensifying pneumatic pressure to hydraulic pressure includes a pneumatic piston movable in a cylinder and connected by a rod with a smaller hydraulic piston. The pneumatic piston is movable from a rest position to... | 12/14/1976 |
| 3990041 | Device for transmitting the condition of a switch between two parts in relative rotary movement A device for transmitting the condition of a switch comprising a first assembly consisting of a switch, a first pair of coils serially connected when the switch is closed, and a second assembly consisting of a second pair of coils, magnetically coupled to... | 11/02/1976 |
| 3985318 | Helicopter blade crack indicator Method and apparatus for continuously detecting cracks in aircraft blades while in flight. A hollow blade is sealed with a pressure differential, either above or below atmospheric. A reduction in the pressure differential such as results from cracks, is d... | 10/12/1976 |
| 3976989 | Electronic pressure cycle indicator A fluid pressure sensor is employed as a safety device for sensing lubricant pressure levels. A timer is activated to turn on a pump at regular intervals to provide lubrication at such intervals. Pump operation supplies lubricant to a dispensing network w... | 08/24/1976 |
| 3965464 | Device for automatically detecting overload on aerial ladder truck A safety device is provided for association with an aerial ladder truck assembly to automatically detect a weight overload on the ladder unit of the assembly at any given angle. The safety means are characterized by providing ladder angle detecting means ... | 06/22/1976 |
| 3946175 | Magnetic pressure indicator for a container A temperature compensated pressure indicator adapted to be mounted within a pressure container includes a reservoir housing and housing member welded together to form a secondary pressure chamber. A bellows member is hermetically mounted within the second... | 03/23/1976 |
| 3944769 | Pressure sensing means and method for making a pressurized container means and system utilizing the same A pressure sensing means having a housing provided with a chamber therein. A double wall fluid operated device is disposed in the chamber of the housing and is carried by the same, the walls of the device defining a chamber therebetween that is interconne... | 03/16/1976 |
| 3939316 | Panic stoplight system for automobiles using a fluid pressure switching device A panic stoplight system for automobiles includes a fluid pressure switching device connected through a flasher with signal lights for operation by the automobile braking system. The fluid pressure switching device closes for flashing the signal lights on... | 02/17/1976 |
| 3938124 | Alarm system sensing device An alarm sensor device of two major portions. The first portion is a securely enclosed chamber containing one or more connector elements and the second portion is a specific length of cable having conductor paths for energy transmission and having at leas... | 02/10/1976 |
| 3938077 | Alarm device for continually indicating the state of air pressure in a plurality of tires An alarm device for informing reduction of pneumatic pressure of tires comprises a group of oscillators each consisting of an oscillator circuit, an electric power supply source thereof, a switch for closing an electric power supply circuit when the inter... | 02/10/1976 |
| 3935558 | Surge detector for turbine engines A pair of pressure transducers are connected to pressure probes positioned in a flow passage of a turbofan engine downstream of the fan and respond to pressure fluctuations which occur in the airstream. One transducer has a high response capability, and i... | 01/27/1976 |
| 3934238 | Differential pressure visual and audible warning signal device for hydraulic and pneumatic systems A combination visual and audible differential pressure warning signal device for fluid power, that is, hydraulic and pneumatic systems such, for example, as those employed in mobile equipment, industrial machinery, or the like. Thus, in a typical use of t... | 01/20/1976 |
| 3932857 | Alarm system sensing device An alarm sensor device having two separable portions. One portion is adhesively attachable to the surface of an object. The other section is supplied with a flow of regulated energy. A measurable energy coupling is provided between the two portions and th... | 01/13/1976 |
