Abstract: Apparatus and method for encoding data in an AC coupled bi-polar data transmission system. A stream of binary data is encoded to produce first and second binary code signals for transmission on a pair of transmission lines. Except as provided by the encoding technique, both binary code signals undergo a change of state for each data bit time. The signal on one line undergoes a transition for each bit time except when the data signal is changing from zero to one. The other transmission line undergoes a change of state for each bit time except when the data signal changes from one to zero. Decoding of the transmitted signals is achieved by applying both signals to an exclusive OR gate.

Abstract: A biscuit joiner for cutting semi-elliptical slots in opposing edges of workpieces which are to be joined along those edges includes a housing adapted to be mounted upon the quill of a multi-purpose woodworking tool, which housing encloses a rotary saw blade adapted to be attached to a spindle projecting from the quill on which the housing is mounted. A spring loaded guide projects from the front face of the housing and has a slot therethrough, so that when the front face of the guide is engaged by an edge of a workpiece to be slotted the guide can be pushed inwardly against spring pressure, allowing the rotary saw blade to be exposed and form a slot in the edge of the workpiece. Adjustable stops are provided on the guide so that a desired depth of cut will automatically be made after adjustment.

Abstract: A combination seal and check valve to be mounted in a filler pipe of a fuel tank to minimize the escape of vapor from the tank when its cap is removed, typically during refueling, comprises an annular body of elastomeric material which includes an internal annular lip for sealing around the outer surface of a fuel nozzle, and an integral check valve portion at the axially inner end thereof. This check valve portion includes at least three gusset members which are of such configuration and proportions that when a fuel nozzle is inserted through the unit, the gusset members are deflected radially outwardly to open a passage through the check valve without being stretched or otherwise distorted by passage of the fuel nozzle therepast.

Abstract: A concrete railroad tie has rail seats defined by plates, which are made from stainless steel or other non-corrodable metal or plastic, cast into the top surface of the tie at the rail seats. The stiffness of the plates should be less than that of the concrete body of the tie and they should have smooth top faces so that they do not cause scuffing of associated rail pads on which the rails rest at the seats. Each plate may have lugs projecting from its underside for providing a mechanical connection with the body of the tie.

Abstract: Gas chromatographic methods and apparatus are disclosed whereby improved separation times and efficiency are achieved by provision of a time-programmable curvilinearly-shaped negative temperature gradient along the length of the chromatographic column. The gas phase sample traveling through the column always passes to a column zone having a lower temperature than the previous column zone. Accordingly, upon elution, sample bandwidths are compressed. Separation times may be decreased when compared to conventional isothermal or temperature programmed gas chromatography.

Abstract: Cross flow diesel particulate traps are disclosed in which a cylindrical canister contains a plurality of individual ceramic trap elements. The canister is provided with inlet openings along one side and outlet openings along another side which respectively communicate with inlet and outlet spaces formed between individual ceramic trap elements. The traps are provided with inlet and outlet plenums which communicate with the respective canister openings for directing exhaust gases through the canister and for collecting the exhaust gases. In one embodiment, the inlet plenum is divided by partitions into zones and a diverter valve directs regeneration gases to selected zones canister regeneration. Ceramic trap elements are disclosed adapted for use in a diesel exhaust gas particulate trap formed with a disc-shaped body of open cell ceramic material with opposite faces terminated by partially surrounding peripheral walls which define inlet and outlet gaps at the respective sides of the element.

Abstract: In screening apparatus for paper making stock comprising a cylindrical screening member dividing the interior of a pressure housing into a supply chamber and an accepts chamber, and also comprising a rotor mounted for rotation in the supply chamber and including a plurality of vanes mounted thereon in angularly spaced relation with each other and in relatively closely spaced relation with the screening member, each of the vanes is of generally airfoil shape and is oriented with its leading edge closest to the screening member and with the surface portion thereof trailing the leading edge diverging from the screening member to create a positive pressure force along the leading edge followed by a negative pressure force between the trailing portion and the screening member.

Abstract: A portable putt training device capable of use indoors or out and useful in training for two different types of putting strokes, e.g. a pendulum style using predominantly wrist motion, and a flat or horizontal stroke using forearm motion with little wrist flexing. The device has a vertically adjustable post in a base which the user can straddle, a swinging guide arm pivoted to the base and extending upward to or beyond the top of the post, a guide track member fixed to the post constraining the guide arm to swing in a plane, and a club retainer pivotally attached to the upper end of the guide arm. The club retainer can also be pivotally attached to the upper end of the post for training of wrist action. In an alternate embodiment the post and base are replaced by a tripod which has a crossbar connecting the bottom end of two legs of the tripod, and having the low pivotal mounting for the guide arm.

Abstract: A device for assisting a computer operator in the use of computer programs includes relatively movable cards bearing data areas thereon arranged in such a way that the operator can, firstly, by visual inspection, readily locate the desired operation to be performed by the program and, secondly, by moving the cards relative to one another, obtain, for that desired operation, information regarding the command to be entered into the computer.

Abstract: The present invention provides an epoxy resin of the formula ##STR1## where A is selected from the group consisting of --C(CH.sub.3).sub.2 --, --C(CF.sub.3).sub.2 --, --S--, --SO.sub.2 --, --CH.sub.2 --, --CO--, --O--, and --C.sub.3 H.sub.6 --, and each B.sub.1, B.sub.2, B.sub.3, and B.sub.4 is independently selected from the group consisting of --H, --F, --Cl, --Br, --I, --CH.sub.2 CH.dbd.CH.sub.2, --CH.sub.3, --C.sub.2 H.sub.5, --C.sub.3 H.sub.7, and --C.sub.4 H.sub.9.The present invention also provides a curable composition comprising an epoxy resin of the foregoing formula (I) and an effective curing amount of a hardener for an epoxy resin. The moisture sensitivity of the cured castings and/or composites based on the epoxy resins is lower than known epoxy resin castings and/or composites that have comparable thermal stability, modulus, strength, processability, and toughness.

Abstract: The present invention relates to a patient support apparatus useful during x-raying. The apparatus includes a frame having a graduated scale along the length of at least one side thereof. The frame has means for supporting an x-ray film cartridge shuttle thereon and permitting movement of the x-ray film cartridge shuttle along the length of the frame. The apparatus also includes a rod for positioning the x-ray film cartridge shuttle along the length of the frame. The rod has a graduated scale along the length thereof. The units of the graduated scale of the rod correspond to the units of the graduated scale of the frame.

Abstract: Conventional night vision goggles are provided with heads-up display information at the same focus and in the same field of view as the intensified image. The heads-up display information is typically generated by a remotely located cathode ray tube and transferred to the goggles by a fiber optic cable where it is then introduced into one of the eyepieces, which eyepiece is modified to include an image combiner placed inside its outer lens in order to provide substantially the same eye relief and physical dimensions as an unmodified eyepiece. The image combiner is a partially reflective mirror. Additional lenses are provided between the heads-up display and the beam combiner to insure that this additional information is presented to the eye at the same focus as the intensified image.

Abstract: Resins are prepared by Diels-Alder polymerization of compounds of the formula ##STR1## where R is a divalent linking group.

Abstract: A bowl for temporarily storing a coiled wire to be used to guide a catheter into the heart of a patient includes a plurality of angularly spaced lugs projecting inwardly from the inner surface thereof at a location near the vertical center of the bowl to define a space therebelow for receiving the coiled wire. When the bowl is filled with heparin solution up to the level of these lugs and the coiled wire is placed therein below the lugs, it is effectively retained against accidental emergence above the solution and is also protected against accidental kinking when it is withdrawn past the lugs for use. Special provision is made for facilitating the nesting of a plurality of the bowls for shipment or storage while protecting against damage of any of the lugs by the nesting of one bowl in another.

Abstract: A pin seam type of papermaker's wet press felt is disclosed in which a base fabric, joined by a pin seam, has a relatively heavy batting applied to at least one surface. The batting is cut through at the pin seam to form a joint in the batting, defined by opposed free ends. One of the free ends in the batting is formed with a transverse Vee groove, and the opposed free end is formed with a transverse Vee proportioned to be received in the groove, thereby forming an interlocking joint.