Abstract: A mask for manufacturing microcircuits is comprised of a substratum and a layer of matter, such as, for example gold, adjacent the substratum. An aperture is located in the layer of matter. The aperture in the layer of matter exhibits a cross-section resembling an inverted isosceles trapezoid. The method for manufacture of the mask comprises the steps of appositioning a patterned layer of photoresist to a layer of gold which is adjacent the substratum. The structure comprising the photoresist, the gold layer and the substratum is exposed to a beam of ions having a preselected kinetic energy such that the ions remove gold exposed by apertures in the photoresist layer. The kinetic energy of the ions is selected such that an aperture is eroded in the layer of gold, the aperture exhibiting an inverted isosceles trapezoidal cross-section.

Abstract: Apparatus and processes are utilized to pierce holes in a brittle material by the use of laser induced shock waves. The waves are generated in an environment of compressed gas which confines the shock wave and carries the debris away. The material is moved into and/or through the work area in the y-direction either by a supporting web with associated rollers or sliding action. The laser beam scans in the x-direction and computer control is utilized to either deflect a continuous beam or switch a pulsed beam "on" where a hole is desired in the material.

Abstract: A control system having a thermostatically operated control device for operatively interconnecting a heater to a source of energy when the output effect of the heater is below a predetermined setting of the control device and to disconnect the heater from the source of energy when the output effect of the heater is above the predetermined setting of the control device, the control device operating an indicating light to indicate that the output effect of the heater is still above a certain value when the control means is in an "off" setting thereof.

Abstract: A device for electron-beam heating of materials comprises an electron gun and an electromagnetic electron beam control system with a rectangular magnetic circuit. The opposite rods of the magnetic circuit accommodate beam deflection windings as well as beam correction and spreading windings. An additional winding is also provided on each magnetic circuit rod. The magnetic fields created by the current flowing through said additional windings form a magnetic quadrupole lens. The device permits manipulating the electron beam so as to obtain a sufficiently long and narrow focal spot on the surface being heated, and also the beam deflection angles range from 0.degree. to 45.degree..

Abstract: A process for making a removable cannula using a laser to make a longitudinal cut and a longitudinal score line in the cannula wall and the cannula made thereby.

Abstract: A furnace for firing refractory ware including a vertically movable bell adapted to enclose a car of refractory ware. Means is provided to seal the enclosure defined by the bell, to evacuate air from the sealed bell enclosure, and to deliver a fluidized, chemically inert, non-combustible, high thermal absorption material to the evacuated bell. A plurality of lasers are provided on the bell facing spaced locations therein and are adapted to be fired sequentially. When fired, the light and heat energy from each laser beam is diffused and absorbed by the inert material and is then re-radiated throughout the bell enclosure to fire the refractory ware therein.

Abstract: A thermionic heater cathode assembly of an electron-beam gun, comprising a disc cathode made of a highly-emissive material and disposed near a U-shaped ribbon filament with a thermionic portion and current-carrying sections arranged in parallel, wherein the ends of said ribbon filament sections to be connected to a holder are arranged in a plane normal to the ends of the same sections, adjoining the thermionic portion of said ribbon filament.

Abstract: The present invention relates to logically controlled unique temperature systems, and it more particularly relates to methods and apparatus for establishing and controlling thermal systems wherein sensing means may anticipate temperature conditions at other points, such as at the work or loads and wherein the controlled heating means are related to the thermal capacity of the system. This arrangement is particularly compatible with unique logical control wherein the temperature signal(s) is converted to a digital pulse train for logical analysis, in turn capable of controlling the heating means by discrete energy bursts. Also, the computer or logical means are capable of sounding an alarm in the event of abnormal conditions or conditions deviating from predetermined patterns.

Abstract: A push button switch assembly for use in association with a heating element which heats a liquid medium or the like. The switch assembly generally includes a housing, a first switch mounted in the housing and movable between on and off positions, and a second switch mounted in the housing movable between on and off positions. The second switch is mechanically associated with the first switch so that the second switch is movable from its off position to its on position when the first switch is moved from its off position to its on position. The first switch is also electrically connected to the heating element to turn the element on and off. The first switch is actuated by means of a manually depressable push button mounted on the housing for moving the first switch from its off to its on position. A bimetallic element is provided between the first switch and the liquid medium for moving the first switch from its on position to its off position when the liquid medium reaches a given temperature.

Abstract: An elongate member, such as a tube, is perforated at intervals by intermittently feeding the member endwise through a perforating station containing a laser for directing a laser beam against the member, and pulsing the laser in timed relation to the intermittent movement of the member to produce a laser beam pulse of sufficient duration and intensity to form a hole in the member at selective times or each time when the member is arrested at the station. The particular member described is a thin walled flexible plastic drip irrigation tube which is flattened upon reaching the perforating station, preferably being pre-flattened, and which may have a single water passage defined by two walls, or which may have a primary water passage bounded by a first tube wall and a secondary water passage bounded by the first wall and a second outer tube wall.

Abstract: An electric fluid heater of the type in which the fluid is heated by passing electricity through it includes an electronic temperature control system responsive to a temperature sensor in the fluid for controlling the flow of electric current to the heating electrodes. The electronic controller includes means to limit the maximum current passed by the heating electrodes. Heat generated is controlled to demand by varying the duty cycle of back-to-back SCR's in series with one of the electrodes.

Abstract: Selective laser case hardening is applied to the blended port relief area of the bore of a cast iron, water jacketed, engine cylinder liner to provide improved resistance to scuffing resulting from the rubbing contact of the walls and piston rings of an associated piston. The upper liner bore above the port relief may also be laser hardened to improve wear resistance. Case hardening of the selected area is performed by utilizing a traversed laser beam, preferably forming a single path helical pattern on the liner surface. The port relief area is preferably fully hardened by utilizing a closed helical pattern, while the upper bore may, if desired, be only partially hardened by increasing the lead of the helix to provide an open helical pattern.

Abstract: An electron beam welding machine incorporating a surface seal system which continuously seals the weld chamber located in an indexing table while such chamber is indexed beneath a seal plate carrying the surface seal material. As a result of the pressure differential involved, the seal surface also acts as a bearing surface as the wear plate on the indexing table moves in contact with the seal surface.

Abstract: A vacuum enclosure rests on two parts to be seam-welded by the electron-beam welding technique and surrounds a support for an electron gun. The support is made up of two separable elements, the first element being constituted by a frame applied in vacuum-tight manner against the parts to be welded by means of a seal fitted on one face, the other face being applied against a flange of the second element which forms a bell-housing and is applied against the frame.

Abstract: The leakage current thermostat is utilized in an electric heater assembly including a housing, a heating element mounted in the housing, electrical supply lines to the heating element and an electrically insulating material in contact with at least a portion of the heating element. The material has a temperature-resistance relationship such that the leakage current therethrough is a steep function of temperature. A leakage current thermostat includes a thermostat control circuit which is coupled to the supply lines and which is operative to control the current to the heating element in response to changes in the leakage current. The heating element is preferably formed by printed circuit techniques on a ceramic material which is affixed in a layer to a metal (conductive) base layer and the leakage current from the printed circuit element to the base is measured by the control circuit.

Abstract: A method for obtaining a hole in a workpiece essentially free of a recast layer and heat affected zone with laser radiation is disclosed. Pulses of laser radiation having durations comparable to the time required to vaporize workpiece material, typically less than ten nanoseconds, and power densities at the workpiece sufficient to produce vaporization, typically in excess of a billion watts per square centimeter, are interacted with a workpiece in an oxidizing environment to produce vaporization of workpiece material. The vapor reacts with the gas to produce a vapor oxide which does not adhere to the workpiece resulting in the absence of a recast laywer. A hole having a desired size and shape is obtained by interacting the pulses of radiation with the workpiece at a high rate of repetition, typically in excess of ten pulses per second, until a desired amount of material is removed. The pulse duration is less than the thermal reaction time of the material resulting in the absence of a heat affected zone.

Abstract: A switching means detects a malfunction due to an open circuited or broken state of a temperature sensing element. The switching means overrides a normal control by the temperature sensing element of a heater, so the heater is de-energized by the switching means and possible uncontrolled, dangerous activation of the heater is prevented.

Abstract: An energy demand controller adaptable for a house or building having a plurality of heating zones and appliances. The energy demand controller includes a temperature sensor for each zone, a central controller receptive of all the temperatures from each zone for comparing the sensed temperature to a predetermined value, and a switch panel having solid state switches responsive to commands from the central controller for selectively delivering power from a power source to the heaters and appliances. When the zones require heating because of a first predetermined temperature difference between the sensed temperature and the desired temperature, then the heaters for the various zones are sequentially activated for a short predetermined time interval. When a greater temperature difference exists between the desired level and the sensed level in a particular zone, the heaters for that zone are activated full time.

Abstract: An electron beam welding device having a vacuum chamber in which an electron gun directs a beam of electrons at a work piece, wherein the optical system for viewing the point of impact of the beam with the work piece includes a light reflecting element in the form of a prism. The prism is positioned in the vacuum chamber to one side and closely adjacent the path of the electron beam and has a first surface extending substantially perpendicular to the beam. This surface is protected by a strip of transparent plastic material having a portion extending across the surface of the prism, the strip being movable to permit the portion to be continuously replaced as it becomes clouded. An open mesh conductive screen is positioned between the impact area and the strip to at least partially screen the material from infrared and X-ray radiation, otherwise acts to rapidly reduce the transparency of the strip.

Abstract: A linear acting solenoid directed to energy conservation. The disclosure combines plural elements usable singly or in combination to enable in aggregate a low cost assembly, yielding values of pull-force per watt of input exceeding ten ounces. Size, cost, and temperature rise are reduced, and shading rings are avoided. Novel elements include a composite phase-splitting core, and a unitary magnetic shell forming an efficient divided-path magnetic circuit, the flux therethrough being confluent through armature and core. In valve or other fluid-barrier uses, a thin ferrous armature housing enables pull values exceeding three ounces per watt of input.