Abstract: Dartboard has a first game side which is divided into fifty-two dart target spaces with each space carrying indicia corresponding to the fifty-two cards of the standard bridge deck. Each target space has a slot adjacent one end thereof into which a slot card each having one of the indicia of the standard bridge deck is inserted to thus hide the indicia from other players. The dart board is rotatably mounted to increase random chance and with the players taking turns throwing darts, dart games employing rules similar to poker and other card games can be played with the board. The reverse of the board is divided into spaces, each of which carries the indicia of one side of a six-sided die. Thus, by throwing darts to the reverse side of the board, games having rules similar to dice games can be played, but also employing dart-throwing skill.

Abstract: The ExB mass separator provides a magnetic field B normal to the beam path and potential plate for applying an electric field normal to the magnetic field for maintaining the selected ions in beam 32 along a defined path. Along the path, after the major portion of the unwanted species are deflected from the beam, focus plates 34 and 36 focus the selected species toward the separator opening 38. Downstream potential plates 28 and 30 maintain the defined path for the selected species.

Abstract: A strap cutter is secured to the top structure on an oil well casing and as the discharge pipe supporting a submersible pump is withdrawn, the cutting head of the strap cutter engages with and cuts the straps which secure the pump power cable to the discharge pipe. The strap cutter is manually guided into place but employs the upward motion of the discharge pipe string to supply the cutting force. The method comprises the use of the upward motion to accomplish the cutting step.

Abstract: Inlet into propane cylinder is covered by sliding sleeve which is raised by a float when the tank level reaches desired level. Float is partly counterbalanced by lift spring and is driven into closed position by hydraulic force when motion is initiated by the float.

Abstract: Screw compressor 32 and screw expander 70 are connected into a refrigeration system. The system includes a mist lubrication system which drives oil particles suspended in flowing gas past the compressor and expander bearings for long life operation.

Abstract: Bipolar crossed-field device 10 has outer electrode 12 and inner electrode 18 which define interelectrode space 16. Magnetic field coils 46, 48 operate together to form a magnetic field in the interelectrode space 16 shaped to trap electrons for cascading ionization and plasma formation when viewed from either electrode.

Abstract: Specific impulse of hydrazine thruster is augmented by electrothermally heating the hot gas in heater passages 36 and 37 as it passes from hydrazine dissociation chamber 14 to thrust nozzle 28. Tubular ceramic electric resistance heater 31 performs primary heating. Specific impulse can be raised from 230 to 300 seconds.

Abstract: The first plasma discharge chamber of the dual discharge plasma device contains an electron emitter and a first anode and contains gas at a sufficiently high pressure that the discharge voltage in the first chamber is below the sputtering threshold. The second chamber has a main anode and receives a plume of plasma from the first chamber. The main anode operates at a voltage above the sputtering threshold with a respect to the first anode and the gas in the second chamber is at a low enough pressure for a conventional low pressure plasma discharge which is used as an ion source.

Abstract: Wound foil capacitor has one foil wound sheet 28, 30, 32 extending out of the top of wound capacitor body 14 and has a connector strap 16 attached thereto by electron beam welding. A similar connector strap is electron beam welded to the other capacitor foil extending as wound layers out of the bottom of the body 14.

Abstract: Vacuum gettering system includes first bulk getter 18 of zironium-aluminum alloy and having a heater 22 therein for activation. Second bulk getter 20 of porous silica glasse's is directly adjacent to getter 18 for heating activation. As vacuum enclosure 10 is pumped out, heater 22 heats both getters to activation temperature to drive off gases and vapors during low temperature enclosure baking and pumpout so that at enclosure closeoff both getters are fully activated.

Abstract: Cryogenic refrigeration system employs a power driven screw compressor which delivers pressurized refrigerant gas through a closed system to expand in a screw expander to produce refrigeration. The screw expander is rotatively coupled to the compressor. The screw compressor-screw expander cryogenic system includes heat exchangers and operates on the closed Brayton cycle to produce refrigeration.

Abstract: Substrate for nickel-hydrogen battery electrode is etched from nickel sheet metal to provide inner and outer rims 54, 56 for self centering, a tab 62 on which a lead can be welded and properly distributed openings through conductors for optimum ion flow and electric conduction.

Abstract: Ion chamber 20 receives electrons from cathode 28 and produces ions by electron bombardment in discharge plasma chamber 20. Ions are extracted through ion optics including screen 22 and accelerator electrode 24. Higher ion densities in the center of the discharge chamber are reduced by spoiler 42 which is operated at a potential between cathode and anode potential. This reduces double ionization and central peaking to provide a more uniform ion beam through the optics. By employing laterally positioned spoiler elements beam steering can be accomplished. The ion source is useful wherever a uniform beam profile is desirable as in ion implantation. Controlling the direction of beam density is useful in ion machining and in ion thrusters for space application.

Abstract: A coupler for wavelength multiplexing or demultiplexing of multimode optical signals in optical circuits. Light introduced through an input/output surface at one end of a planar optical waveguide formed within a glass substrate propagates to a convexly curved second end of the waveguide on which is contiguously mounted a flexible, reflective diffraction grating. The light is diffracted by the diffraction grating and focussed by the curved end back onto the first end of the waveguide.In a multiplexer (beam combiner) embodiment, a plurality of optical signal sources, each having a different wavelength component, is aligned along the first end of the waveguide so that light propagating from each of the sources travels through the waveguide to the reflective diffraction grating, is diffracted by the grating and then brought to a common focus at the first end. An optical fiber abutting the first end is positioned at the common focus to receive the combined beams.

Abstract: Stacked plates each have a plurality of thin etched flow passages to be employed in a tank containing gas and liquid for separation to provide gas free liquid. The liquid surface tension in the flow passages that are exposed to the gas provides a force to prevent the gas from entering the liquid galleries until the tank is void of liquid. Such separation is useful in fuel tanks in near zero gravity environment as well as in other separation duties.

Abstract: Primary mirror 12, secondary mirror 14 and tertiary mirror 16 form an anastigmatic relayed image forming optical system which is off-axis and decentered in both aperture and field angle. The secondary and tertiary mirrors are tilted and decenter relative to the optical axis of the primary mirror to enhance image quality. Additional advantages include compact packaging, easy accessibility to all components, and improved shielding of unwanted out-of-field radiation.

Abstract: Orientation independent ignitron 10 has a cooled cathode 28 which carries thin mercury film 58 which is held in place by surface tension forces so that it is independent of orientation. Ignitor 48 starts conduction which continues until mercury exhaustion or shut off by an external circuit. During nonconductive portions of the duty cycle, the mercury recondenses on the cooled cathode 30.

Abstract: Electron beam lens 22 can be operated in a first mode to demagnify and focus the image of electron source 14 at image plane 32. Electron optical lens 34 and 46 further demagnify the image plate 32 through the focal point 60 on the face of target 58 to provide a scannable exposure spot. Electron optical lens 22 can be operated in the second mode which floods aperture 32 so that the image of the aperture is demagnified and focused on target 58 to provide a large exposure area.

Abstract: Partially circular rocker is arcuately curved and has inwardly directed king pins positioned opposite from each other at the ends of the curve. One king pin is assigned to each competitor. Rings are tossed so that each competitor attempts to ring his own king pin and, at the same time, knock his competitor's ring off his competitor's king pin. A balance weight on the rocker is moved at each turn to level the rocker.

Abstract: The ion implantation system includes a separate vacuum housing 102 for the ion source and the target chamber 118. The ribbon beam ion source 10 provides a footprint 162 on the wafer wheel 126 of such shape as to permit short traverse of the wafer wheel 126 for full wafer scan.