Abstract: The present invention relates to improvements in processes of preparing dinitrated aromatic compounds, particularly dinitrated aniline and dinitrated substituted aniline compounds, employing relatively dilute and then more concentrated nitric acid as the nitrating agent.

Abstract: A video editing system uses apparatus for connection with a video playback machine (first VCR) and a dub video recorder, (second VCR). The apparatus includes tone generator circuitry for generating an edit tone to be recorded upon an audio track of a color master video tape which has been preselected for edit duplication. Control circuits allow selectively supplying the edit tone to the first VCR for recording upon the audio track to differentiate selected from unselected portions of the video track of the tape. Tone decoder circuits decode the recorded edit tone upon playback of the master tape. Circuits control starting and pausing of the second VCR in response to the decoded presence or absence of the recorded edit tone. Accordingly, the second VCR when connected to the first VCR produces an edited first copy video tape by duplication only of the selected portions of the master video tape.

Abstract: For use with a hydrocarbon-fueled furnace whose secondary heat exchanger so cools the combusted gas as to condense much of its water vapor, and having a blower to the flue, a combined trap and drain is provided for the condensate formed both in the heat exchanger and in the flue. At the base of the flue is a standpipe whose upper overflow outlet is connected to a dip tube. Between the level of its lower end and the overflow level is a side inlet into the standpipe, connected to a tube leading downward from the heat exchanger's condenser. When the furnace blower applies both negative pressure to the condenser and positive pressure to the flue, the water levels in the trap and tube adjust to balance out these pressures.

Abstract: A reader-writer for magnetic cards substantially reduces "jitter" or chattering vibrations which otherwise imperil the accuracy of the read-write functions. The read-write head is itself mounted rigidly for operating while the magnetic card passes along a planar tray surface. A soft rubber anvil roll is mounted directly opposite, for free idling rotation on the same shaft which impels a rubber driving wheel.In contrast with conventional constructions using a spring-mounted head or anvil, the present rigidly mounted head in combination with the free idling soft anvil roll avoids the generation of, and damps out, vibrations, which otherwise might follow from exciting forces such as irregularities in driving friction. The greatly improved accuracy makes feasible the use of debit cards, and has unexpectedly reduced head wear.

Abstract: Integral transverse flanges on duct sections made up, for example, of two L-shaped work pieces, are readily assembled into permanent rigid section-joining frames. At the frame corners, the interfitted flanged ends of corner pieces are trapped, adjacent to the integral flange webs, behind an outward-turned ridge on a surface of the duct and beneath an inward and backward turned spring margin having a progression of lanced projections. Tabs, extending across the lines of juncture of the L-shaped pieces along the outward turned ridge, are peened over to seal the joints of the work pieces positively and prevent the escape of air. Easily applied clips hold the flanges of the adjacent duct sections tightly against each other, and may be used also to retain narrow reinforcing bars likewise behind the out turned ridge and beneath the spring margins.

Abstract: A composite baseball bat has a unique tapered aluminum spar encased in polyurethane foam. The tapered spar is formed by swaging, starting with an aluminum tube whose outer diameter and wall thickness are those for the barrel section of the bat. A tapering portion is swaged to a decreasing outer diameter and increasing wall thickness, which is then constant over the handle portion of the bat. This construction yields far greater stiffness and freedom from objectionable vibrations.

Abstract: A method of magnetic encoding of credit instruments having a strip form magnetic recording medium provides at least one data field on the strip. First and second magnetic field orientations are selected for recordation on the medium of successive, adjacent bit regions in an alternating field orientation pattern with the transition between such orientations defining the transition from one bit region to the next, signalling the initiation of a recorded bit representing either a binary "1" or a binary "0". A first bit region length d.sub.1 for representing one of the binary values "0" and a second bit region length d.sub.2 for representing the other binary value as well as the ratio of d.sub.1 /d.sub.2 are selected, with d.sub.1 /d.sub.2 being from about 0.1 to about 0.5. Thus, the magnetic field transition between adjacent bit regions signals a binary bit and the length of each bit region represents its binary value.

Abstract: Sealed, molded fiberglass doors and the framing members which surround them, such as used on utility trucks and other purposes, are in the present invention molded in a single piece. The door panel, originally formed recessed inwardly from the framing member, is bounded by an outward facing V-groove whose outer wall slopes toward the framing member. The integral molded part is then severed to divide the sloping outer wall into a framing member flange and the outer margin of a V-flange which bounds the door. On fitting the cut edge of this V-flange with a heavily cushioned channel gasket, and presenting the door against the flange of the framing member, a secure seal is effected without any tendency to pull the gasket off the door edge, even when frozen. Forming the parts integrally not only saves mold costs and material costs, but also assures perfect fit.

Abstract: A heater rack assembly, of the type which supports an electric heating coil in a pattern of parallel rows in a plane, utilizes double-ended stand-off insulators which are formed wafer-like in the plane. The insulators have, at each end, pairs of hook portions facing each other to provide a throat, which opens into a wire-accommodating slot behind the hook tips, the slot converging toward the center at an angle of 150.degree. or less. Adjacent turns of the coil are to be accommodated within the slot. Its convergence retains within the slot adjacent coil turns which might otherwise escape, requiring for such escape what is in effect a reverse in-plane twisting displacement.

Abstract: A compact secondary heat exchanger, installed above the preliminary heat exchanger in a down draft-type gas burning furnace, so greatly reduces combustion gas temperature as to recover a portion of the latent heat in the water vapor created by burning the hydrocarbon gas.

Abstract: Use of ferri-magnetic reactive iron oxide particles to react hydrogen sulfide in water, hydrocarbon liquids or drilling mud affords quick, effective scavenging of these liquids without accumulation of particulate matter and without wasting the reactive particles. The reaction product is environmentally safe, so that it may be disposed of on a simple waste heap.A quantity of the magnetic iron oxide particles, principally a synthetic porous Fe.sub.3 O.sub.4, is suspended in the liquid. The quantity added is in excess of that required for the reaction with the hydrogen sulfide in order to speed the reaction time and provide a large margin of safety. In use, the reactive iron oxide particles contact and react the hydrogen sulfide, forming a non-magnetic particulate product of reaction. Thus, if used to scavenge a drilling mud, this contact and reaction occurs as the mud, bearing the drill cuttings, rises through the drilling formation.

Abstract: Simple apparatus permits material, such as a hand cleaner whose viscosity is too great to flow downward under the force of gravity, to be loaded by inverting a can of the material and pressing downward onto the top of a reservoir sleeve. For pumped dispensing, two rubber valves of the "duck-bill" type are provided in the flow line downward from the reservoir bottom wall. While their lips are so soft as to be unable to restrain the down flow of conventional liquid, this is no problem when used with the viscous material. The material is dispensed by pumping until its level in the reservor is so low that an air channel forms downward through the material to the valved flow line, preventing further dispensing. At this stage, inverting and pressing downward a second can of material drives air in the reservoir downward through the air channel so formed and out through the soft rubber valves, so that dispensing can recommence.

Abstract: A portable electric baseboard heater includes a unitary structural back plate having a central vertical portion bounded by an integral lower triangular closed box-like structure having a downwardly sloping forward surface and an integral upper triangular portion having an upwardly sloping forward surface, a horizontal top surface and a rear vertical wall in the same plane as the central portion and terminating spacedly thereabove to provide a horizontal opening aft of the upwardly sloping forward surface. An angularly bent or molded plastic liner covers the interior of a portion of the top and upwardly sloping surfaces of the upper triangular portion to form an internal thermally insulative handle accessible through the horizontal opening to permit lifting of the heater. The lower triangular portion serves as a protective raceway for power supply wires to an electric finned tube heater assembly supported by the back plate between the upper and lower triangular portions.

Abstract: The head of a patient is held in place horizontally on the indexable sliding cradle of an X-ray scanner by a vertical ring encircling the head having radiolucent rests supporting the head behind the ears at the mastoid processes and beneath the eyes at the cheekbone area. Adjustable horizontally-projecting instrument support structure is carriage-mounted on an arcuate track in the ring between the forward rests and has a horizontally-bored instrument guide-holder of such density as to appear on an X-ray scan and positionable adjacent to the head with its horizontal bore in the plane of any indexable scanning section of the X-ray scanner. By scanning the head and adjacent guide holder, the holder may be positioned with its bore in the same plane as and on a line directed to a point of interest in the brain. Thereafter, the holder may be utilized to guide a surgical needle to the point of interest.

Abstract: An offset-axis type wind generator uses a passive cyclic pitch-change rotor whose shaft axis is inclined downward and aft, with its sense of rotation selected so that the yaw component of the shaft torque at least partially of the shaft torque offsets that component of thrust which accompanies power extraction. A wind-alignment vane extends from a boom mounted on a furling hinge, equipped with mechanism to limit the vane's anti-furling moment to balance only the remainder of the moment of rotor thrust. Hence, disengagement of power extraction does not cause the rotor to overspeed, and the machine may idle even in gale-force winds, furled to nearly 90.degree..

Abstract: A door check of the swingable slotted hasp type provides two extents of opening, utilizing a broader width of slot which continues outward in a slot of narrower width. Two different depths of slide member are provided. In one embodiment these are spaced axially along a horizontal projection from a housing on the door. In another, the slide is oblong, and is rotatable through 90.degree. to present the two different depths.

Abstract: A stand including a square vessel in which the trunk of a Christmas tree is clamped and held, has a pair of clamping screws extending inward from its opposite corners, along a common diagonal axis. The inner ends of the clamping screws have narrowed necks over which fit slotted clamping angles, whose bottom ends are slotted upwardly to fit onto a diagonal rib in vertical registration with the clamping screw axis. As the screws are advanced inwardly the clamping angles are guided and stabilized by the rib, to maintain parallelism with the square corners of the vessel.