Abstract: A fiber reinforced plastic well screen including a slotted central section and unslotted end fitting portions is formed by manipulating a single bundle of resin-coated filaments longitudinally and circumferentially relative to a mandrel. The mandrel has a series of helically grooved segments which cooperate with each other to cause the filament bundle to form the slotted central section. Longitudinal wraps, which are looped under tension from one end of the mandrel to the other in the region between each adjacent pair of segments, are intimately bonded to all of the helical circumferential wraps which form the central section as well as those that form the end fitting portions. One removable end cap portion of the mandrel is preferably externally threaded to produce an integral internal thread in the formed well screen. A tubular internal sleeve portion of the mandrel is removable to permit the helically grooved segments to be collapsed inwardly after the well screen is cured.

Abstract: Molded elastomeric framing member has internal horizontal and vertical slots which are adapted to frictionally engage several of the longitudinal profile surface wires and portions of the transverse support bar members along a side edge of a flat deck screen panel. Parallel top and bottom portions of the framing member are adapted to be engaged by a support surface of a vibrating screen apparatus and a clamping apparatus carried by said screen apparatus. The framing member prevents metal-to-metal contact between the screen panel and vibrating apparatus, thus reducing the noise level of the apparatus. It also helps protect persons handling the panel from possible injury by rough edges and eliminates the expense and labor associated with the welding of side panels to the ends of the support bars. To prevent the screen panel from becoming electrically isolated from the vibrating screen apparatus, the elastomeric framing member can be made electrically conductive.

Abstract: Improved framing system for a multi-passenger seat incorporates a generally inverted L-shaped rear leg whose shorter leg portion is joined to the rear stretcher tube at its free end and to a compression member at its point of intersection with its longer leg portion. The compression member and short leg portion form one side of a triangle which includes the front leg and a support member connecting the front and rear stretcher tubes. The longer leg portion forms one leg of a triangle which includes the compression member and a seat track covering member. The design provides greatly improved passenger leg room for close pitch seating arrangements.

Abstract: Screen member for use in fixed or rotating screen support devices and in either a vibrating or non-vibrating mode for grading or dewatering comprises a first plurality of elongated, parallel surface wire members which are formed by extruding a resilient, abrasion resistant layer of elastomeric material completely around a core portion which is more rigid than the elastomeric layer. A second plurality of elongated, parallel support rod members arranged transverse to the first plurality are also formed by extruding a layer of elastomeric material completely around a more rigid core portion. The first and second plurality of wire members are bonded to each other at every intersection by a partial melting together of the contacting elastomeric layers under pressure.

Abstract: Vent cap assembly for a monitoring well permits venting from a well riser pipe while positively preventing contamination of the well by vandals. Tabs having apertures are integrally attached to the pipe and to an axially elongated vent cap. A padlock may be placed through the apertures to prevent unauthorized removal of the cap, but whether or not the cap is locked, the tab on the riser pipe causes the inner end surface of the cap to be spaced slightly above the riser pipe to insure that venting will always be possible.

Abstract: Improved method of joining a rigid thermoplastic fitting to a rigid thermoplastic well screen having longitudinal support rods utilizes pressure and friction generated heat to bond a reduced diameter tubular, rigid thermoplastic sleeve portion of the fitting to the inner surface of the screen. The method permits the joining, without the use of solvents, of screens and fittings of PVC, polypropylene, or ABS, for example, which have the same outer diameters. The sleeve portion of the fitting has an outer diameter which is greater than the inner diameter of the well screen. The assembly method requires that the parts to be mated be rotated rapidly relative to each other as they are forced axially into interfering, telescopic engagement. The overlapping members are fused along a generally conically tapered plane with the material which is melted during rotation being deposited in the circumferential spaces between the screen's support rods.

Abstract: Exhaust emissions control system provides effective control of hydrocarbons, carbon monoxide, and nitrogen oxides by adjusting the air-fuel ratio of an internal combustion engine having a catalytic converter in its exhaust path in response to the percentage oxygen content of the exhaust gases as measured by a voltage generating oxygen sensor positioned in the exhaust path. The electrical signal produced by the oxygen sensor is compared to a set point signal which corresponds to the desired oxygen content which prevails when the conversion of the exhaust gases is optimized and a correcting step adjustment is made in the air-fuel ratio when there is a difference in the signals. To minimize hunting and still provide a relatively rapid response, the system incorporates a time delay to permit each adjustment made in the air-fuel ratio to be reflected in the output of the exhaust gases before the oxygen content of such exhaust gases is sensed preliminary to make succeeding step adjustments.

Abstract: Rectangular poppet damper or valve has particular utility as an isolation damper in a fabric filter dust collector and includes integral gas flow turning means which are positioned so as to minimize pressure drop. The poppet plate is pivoted at one end to the floor of an inlet manifold and has a pair of gas straightening vanes attached to its underside. One of the vanes is near the pivoted end and the other is generally parallel to the poppet plate and has lead-in and exit portions which gently turn the gas about 90.degree.. Where the gases are to be directed to a plurality of collectors, a damper is preferably provided for each, with the angles of the various poppet plates being individually adjustable so as to divide the flow in any proportion desired.

Abstract: A suspension seat has a seat part, which includes a seat support frame and a back rest frame pivoted about a horizontal axis to the seat support frame, the seat part being mounted through a spring suspension on a base part, and a vibration damper of the piston and cylinder type pivotally connected between the seat and base parts. The lower end of the vibration damper is pivoted to the base part.The upper end of the vibration damper is slidably connected to the back rest frame and pivotally connected to the upper closed end of a yoke whose lower ends are pivoted to the seat part as closely as convenient to the pivotal connection between the vibration damper and the base part to allow tilting of the back rest frame without significantly varying the distance between the ends of the vibration damper.

Abstract: A plurality of monolithic catalyst support elements are mounted in parallel in a plurality of recessed retaining portions of a bulkhead member separating an inlet plenum from an outlet plenum. The catalyst support elements are each compressed at one end into contact with a gasket member in each retaining portion by force applying means positioned so as to contact the other end of a plurality of catalyst support elements at one time. In one embodiment, the various elements of the apparatus are formed of materials having different coefficients of expansion and related lengths so as to maintain compression without the use of specific spring elements. Other embodiments use springs to compress either a single catalyst support element at a time or several at once.

Abstract: A cabinet type enclosure, for refrigerating a plurality of food items on a plurality of specially configured meal trays has a plurality of thin, generally horizontal, fixedly mounted heater shelf members extending into the enclosed space from one side wall thereof. One or more covered containers of food to be heated are positioned on one side of the trays and are mounted on the trays slightly above the top surface of the tray and with their bottom surfaces in contact with heater plates on the heater shelf members. The meal trays have integral transverse abutment means which cooperate with portions of a container for hot food placed on the tray adjacent the abutment means for preventing longitudinal movement of the hot food container past the transverse abutment means by frictional contact of the container with the heater shelf as the tray is moved into or out of the enclosure and relative to the heater shelf along tray guides.

Abstract: Plastic well screen has tapered, undercut slots formed by a laser beam focused through a lens having its focal point located at or slightly away from the surface of the plastic cylinder being slotted so that the laser beam diverges as it passes through the plastic. The cylinder is rotated and simultaneously moved axially relative to the laser beam to produce a series of transverse slots. In one embodiment, the laser beam is interrupted to provide continuous longitudinal support portions in the cylinder. In a modified embodiment, the cylinder has integral internal ribs which remain intact even though the laser is operated continuously to remove surface material located between the ribs and the laser beam.

Abstract: Arrangement for resiliently mounting a ceramic monolithic type catalytic converter element in a metal housing with a blanket of knit wire mesh material includes at least one circumferential band of high temperature intumescent material containing ceramic fibers positioned within the wire mesh blanket which prevents virtually all bypass leakage around the element and substantially reduces the temperature of the wire mesh.

Abstract: Improved double wall tubing assembly which is especially useful in heat exchangers of the "coil-in-can" type for solar applications has a double wall construction which insures that a leak developing from a failure in either of the walls will not result in a mixing of fluid external to the outer tube with the fluid flowing internally of the inner tube. An outwardly projecting helical fin configuration formed on the outer surface of the inner tube provides an effective heat transfer medium between the inner and outer walls of the tube assembly while defining a spiral flow channel through which leakage entering through either wall can flow and be detected. A method of making the double wall tube assembly is disclosed wherein a finned outer tube is assembled over a previously finned inner tube. The assembled tubes are then brought into firm mechanical contact by the step of forming the assembled tubes into a coil and/or by expanding the inner tube.

Abstract: Apparatus for producing annular corrugations in the wall of thin metal tubing in the manufacture of corrugated metal hose includes a plurality of dies. Each die comprises a helical rib of greater than 360.degree. extent formed on the inner rim of an annular ring with the ribs on successive dies being progressively thinner and having successively closer pitches so as to progressively deepen the corrugations and make them narrower. The dies are preferably mounted to rotate in synchronization with each other at identical angular speeds, and are arranged in pairs in one or more stages with the dies in each stage engaging opposite sides of the tube.

Abstract: Solid electrolyte oxygen sensor incorporates a sealed integral heater which is positioned internally of the tubular wall of the ceramic sensor body in the region radially adjacent the disc shaped solid electrolyte which is mounted transverse to the axis of the body. A plurality of small longitudinal apertures are formed in the body wall by extrusion. A groove formed in the external side wall of the body provides access so that a resistance heating wire can be threaded alternately in opposite directions through the small apertures. The wire bends are accommodated by the side wall groove and an end wall groove, each of which can be sealed with a castable ceramic after the wire is installed.

Abstract: A seat, in particular for a tractor, has a shoulder support mounted at the upper end of a backrest of the seat on a hinge device. The hinge device, when locked, holds the shoulder support in an upright position but, when released, allows the shoulder support to be tilted downwardly to a horizontal position to support an arm and shoulder of the seat occupant when plowing or reversing the tractor.

Abstract: Plastic well screen has tapered, undercut slots formed by a laser beam focused through a lens having its focal point located at or slightly away from the surface of the plastic cylinder being slotted so that the laser beam diverges as it passes through the plastic. The cylinder is rotated and simultaneously moved axially relative to the laser beam to produce a series of transverse slots. In one embodiment, the laser beam is interrupted to provide continuous longitudinal support portions in the cylinder. In a modified embodiment, the cylinder has integral internal ribs which remain intact even though the laser is operated continuously to remove surface material located between the ribs and the laser beam.

Abstract: The invention relates to a seat having a movable lumbar support. An arcuate lumbar support is mounted on a back rest frame of the seat by a mechanism which is operable to move the lumbar support forwards or backwards or to tilt the lumbar support as its axis moves vertical to effect a rolling action thereby to raise or lower the level at which it supports a seat occupant. A screwthread in the mechanism is spring-supported to reduce shock applied by the lumbar support.