Abstract: Unclean fuel, such as coal is reduced to particle size passing 200 mesh in an attrition mill. Pyrite and ash removal is performed in conjunction with the attrition milling. The resulting fine particles are combusted in the turbine exhaust gas and the products of combustion indirectly heat the turbine operating gas. Control is provided by bypass around the heat exchanger and/or auxiliary clean fuel combustion.

Abstract: An apparatus and a method for air-conditioning by which solar heat is collected and utilized in winter heating and in summer cooling and humidity adjustment. A hygroscopic liquid circulates through a solar heat collector and a reservoir thereof to accumulate sufficient heat to furnish energy for (1) dehumidification, adiabatic cooling of air, and concentrating of the hygroscopic liquid in summertime operation, or alternatively, heating of air in winter time.

Abstract: Cryogenic liquid coolant for cooling the rotor of a superconducting generator is deposited on the inner surface of a rotating conduit extending within the rotor, forming an annulus of liquid surrounding a vapor core. The liquid coolant from the rotating tube is transferred to two radial tubes in the rotor and, upon emerging therefrom, splashes on the surface of a pool of coolant bathing the rotor windings. Evaporated coolant is returned from the rotor in separate streams from the driven end and the collector end, allowing cooling of the driven and collector ends to be equalized by independently controlling flow of the returning streams.

Abstract: Rooms are cooled by water circulating radiators of a heating installation by utilizing liquid nitrogen to cool the water flowing through the radiators or by circulating cold gaseous nitrogen through the radiators after draining the water.

Abstract: An absorption refrigeration system is adapted to be powered by solar energy or a source of relatively low temperature waste heat. A control system automatically adjusts the maximum energizing temperature as the temperature of the cooling water, used to cool the condenser and absorber coils, varies.

Abstract: A freezing unit is described having plural compartments on upper and lower levels for accommodating air moving means, refrigeration coils and conveyors for receiving and maintaining the articles to be frozen in the unit. The refrigeration coils are disposed in a compartment on the lower level with compartments on either side. The air moving means is disposed over one of the side compartments and the conveyors can be disposed either over the other side compartment, adjacent to it or within it. This arrangement of components permits ease of access and allows plural conveyors to be deployed and used together or alternatively in their respective compartments. Partitions with variable closures are also provided for directing the flow of refrigerated air to the desired compartments.

Abstract: An agitator for a washing machine of the vertical axis type has an upper auger portion with a helical vane thereon and a coaxial lower skirt portion having upstanding agitation and scrubbing vanes thereon. The lower portion is driven in to and fro oscillations, while the upper portion is driven in stepwise, unidirectional rotations through a one-way, non-ratcheting clutch. The clutch has a double-lobed, cam carried with the lower, oscillating portion of the agitator. A pair of clutch members carried radially outwardly of the cam are each engageable on a spiral surface thereof with a corresponding thrusting surface of each of the cam lobes and on a generally radially extending surface with a capture and retraction surface of each cam lobe. Teeth on the outer portions of the clutch members and on an inner surface of the auger portion are selectively forcibly engaged on the driving oscillation and are positively disengaged on the reverse oscillation, to provide the desired one-way drive to the auger element.

Abstract: An anti-theft device of the type which clamps upon an auto tire for resisting rotation of the tire. The clamp is formed of a pair of pivoting arms which may be manually closed upon opposite sides of a tire. Locking means are provided to secure the clamp and prevent unauthorized removal.

Abstract: The invention contemplates a key retainer with a key-retaining bail extending beyond one end of a case, for selective retention of one or more keys. The combination involves the bail formed as an integral hook-like part of pivoted body structure within the case. Pivotal action is limited, and deliberate manual actuation of the body structure against a preloading spring is necessary to displace the free end of the hook from (a) a first normally retained position in which the hook is effectively closed by its relation to the case, to (b) a second and temporary position in which the free end of the hook is sufficiently upwardly offset from the case to permit selective key insertion in and/or removal from the bail.

Abstract: Apparatus for forming circular rims for bicycle wheels from metal profiled strip material in which first strip pieces are cut to a length corresponding to the circumferential length of the rims, curved end portions are formed on each strip piece, and each strip piece is introduced into a three-roll ring rolling apparatus. After the strip piece has been worked up to the trailing curved end portion thereof, the adjustable middle roll of the rolling apparatus is shifted a small distance towards the two outer rolls into a position corresponding with a substantially bending-free passage of the trailing curved end portion of the strip piece.

Abstract: A method of manufacturing an endless metallic belt of high strength for use as a drive belt or a part of a drive belt. A stress gradient is introduced in the belt in the radial direction thereof by bending the belt at such a radius as to produce plastic deformation of the metal. The belt is first subjected to tensile stress, which stress is maintained during the bending process.

Abstract: Rotary internal pipe bending mandrel, wherein sets of pipe engagement elements at opposite sides of the pipe interior are actuated by generally radially disposed toggle elements which expand and retract the pipe engagement elements by rotations of a central assembly. The elements which support the pipe engagement elements are disposed in circularly spaced groups which are axially spaced along the direction of the pipe, and each group is separately expanded by a separate fluid motor assembly. The apparatus has improved the load bearing characteristics because it has positive end engagements of the toggles, whereby the pins or shafts on which the toggles are pivotally mounted are not excessively strained.

Abstract: The state of mobility of a substance--e.g., the pour point of a liquid, is determined by disposing in or in contact with the substance a shear device at the bottom end of a substantially vertical elongate probe mounted for rotation about its vertical rotational axis. The probe is urged to a datum position by suitable means (e.g. a pair of magnets) and, intermittently, a rotational force is momentarily applied to the probe at its top end to cause rotation about the probe axis away from the datum position. If the probe rotates, because the mobility of the substance so permits, a member attached to the probe interupts a light path between a light source and a light sensor, giving rise to a signal indicative of the mobility of the substance. When there is no, or slow, rotation, the non-interruption of the light path over a selected time interval indicates a reduced mobility of the substance.

Abstract: A method for measuring the volume of air entrained in hydraulic fluid by using improved apparatus for measuring separately the particle contamination count in the fluid and the air bubble entrainment plus the particle contamination count, the difference of which equals the air entrainment count from which the volume of air entrained is determinable.

Abstract: A gas leak detection system is provided which includes a large number of small diameter flexible tubes which are mounted in alignment and which extend down close to the surface of the earth or the street where the gas leak is to be detected. The total internal volume of the system is kept to a minimum by using very small diameter tubes and minimizing the volume included in the system. Preferably the total volume in the system is less than 100 cubic centimeters. This provides for a response time of three seconds or less with the small portable ionization type gas detectors which are commercially available. Manifold arrangements are provided which give equal length trasmission paths from all of the sampling tubes. A counterweighted boom is employed to sense leaks beyond the curb adjacent the street where the vehicle is travelling.

Abstract: Water penetration of bituminous pavement is measured by a conduit comprising a cylindrical tube having a flat outwardly extending lower flange and a closed top having a circular center opening into which is engaged an upwardly extending graduated cylinder open at both ends having a diameter significantly smaller than the cylindrical tube. The flat lower rim is adapted to hold a sealant on its lower surface and a weight having a central opening fitted around the cylindrical tube on its upper surface. The weight causes the sealant to seal the apparatus to the pavement in a fluid tight relationship and when the apparatus is filled with water the degree of water penetration into the pavement can be determined by the change of water volume in the graduated cylinder.

Abstract: Material properties related to strength are measured, using a force measuring device in cooperation with a testing device which is placed in contact with the material being measured while the material being measured is in a molten state, the testing device being such that the molten material can flow through at least a part of the testing device.

Abstract: An improved apparatus for determining the Brinell hardness of railway vehicle wheels comprising a receiving means to accept and retain the wheel in a substantially vertical position; an elevator to raise and lower the receiving means in a substantially vertical plane; a polishing attachment to polish at least a portion of the wheel being held by the receiving means; and a Brinell testing device to determine the hardness of the wheel at one or more points which have previously been polished by the polishing attachment.

Abstract: The present invention pertains to a method for setting the side to side balance of a multi-barreled carburetor on an automobile engine which is running smoothly with no misfiring cylinders and which is set to factory specifications for curb idle speed and timing.

Abstract: Method and apparatus for amplification of amplitude-modulated, ultrasonic frequency, electronic signals providing superior loss-of-carrier signal detection. Low noise integrated circuits are employed to provide high amplification of low level input signals without adding appreciable electrical noise during the amplification process. An automatic gain control (AGC) circuit ensures a nearly constant level of ultrasonic signal amplitudes from the amplifier without excessive amplification of electrical noise under conditions of low applied input signals. The electrical noise, inherent in the system, has only minimal effect on the loss-of-carrier detector.

Abstract: A low pressure drop air flowmeter for an automotive engine is disclosed. The meter includes a main air flow passage, a relatively small venturi tube receiving a portion of the air flow, a pressure port for sensing stagnation pressure in the main passage, a pressure port for sensing static pressure in the throat of the venturi, and a set of stationary swirl vanes disposed adjacent the outlet of the venturi and operative to impart a swirl to the remainder of the air in the main passage, thereby creating a reduced pressure at the venturi outlet for amplifying the pressure difference between the stagnation and static pressures without appreciably increasing the pressure drop across the flowmeter. Also disclosed is a solenoid valve having a single valving member operative in one position to communicate the stagnation pressure to an absolute pressure transducer and operative in another position to communicate the static pressure to the transducer.

Abstract: The invention contemplates a sealed electrical-meter construction for measuring an electrical quantity such as an electrical resistance, and having particular application to the display of liquid-level where measured resistance is a function of observed liquid level. The meter construction provides a transparent side port at which a solar-cell assembly is exposed to external light, and the voltage output of the cell, after reduction to assure constant-voltage level is used to power the measuring circuit. Fiber-optics elements at the transparent side port convey light to the display face of the meter, so that even a flashlight at nighttime is sufficient to excite the solar-cell assembly and illuminate the display face.

Abstract: An inductive level sensor has inductively coupled primary and secondary windings. Circuitry drives the primary with an AC signal of constant current magnitude and selected frequency f to induce in the secondary, a voltage signal V of magnitude .vertline.V.vertline., frequency f and phase difference .phi. from the driving signal. Circuitry operates to generate a voltage output signal proportional to .vertline.V.vertline. cos (.phi.-.theta.), where .theta. is a selectively set phase shift factor. By properly and selectively adjusting the frequency f and phase shift factor .theta., an output signal .vertline.V.vertline. cos (.phi.-.theta.) can be provided which self-compensates for changes in mutual inductance caused by operating temperature variations so that an output signal is produced which is substantially linearly proportional to changes in the level of a pool of liquid metal being monitored. Disclosed also is calibration circuitry and circuitry for converting the voltage signal .vertline.V.vertline.

Abstract: A temperature sensor particularly adapted for use with digital displays or controls comprises an oscillator circuit coupled to a capacitor formed of ferroelectric material in order to provide a linear relation of frequency with temperature. Both chip and multilayer capacitors are shown to be useful as the sensing element.

Abstract: A test for determining the sulfur content of the base cast iron used for the production of nodular iron or iron containing compacted graphite. A sample of the molten base cast iron is removed from the melt, then a known amount of a nodular iron inoculant or a compacted iron inoculant is added to the molten metal. The molten metal sample is then cast into test bar or test wedge, solidified and tested to determine whether the bar or wedge is nodular iron or iron containing compacted graphite. The test may be fractured and inspected to visually determine whether the fracture is gray or white. Alternatively, the wedge or bar may be ultrasonically tested to determine whether the wedge or bar contains flake graphite or nodular graphite or compacted graphite. As a further alternative, the cooling or solidification curve of the molten metal sample, after inoculation, can be determined and compared with the cooling curve from a molten base cast iron sample.

Abstract: A method and system for monitoring the angular deformation of structural elements in a composite structure in response to imposed mechanical vibrations in which the structure is part of the monitoring system.A plurality of angular motion signal generating sensors are provided at different selected locations in a composite structure, each sensor being associated to a corresponding structural element. Signals output from the sensors in response to vibrations propagated within the composite structure are detected and a vibration signature for the entire structure is established. The sensor outputs are subsequently monitored and compared with the previously established vibration signature to detect differences therebetween designating changes in the vibration response and potential structural failures.The angular motion sensors employ a magnet and a coil in which a voltage and current are induced in response to angular deflections of the structural member to which the sensor is attached.

Abstract: A plurality of water tanks hold a plurality of ultrasonic transducers, each providing a different angle of incidence for ultrasonic radiation for a tube or pipe passing through the tank. Water of a specific temperature is fed to the particular tank being used and in conjunction with a particularly oriented transducer, a particular test angle of refraction is established. Through a particular range of different transducer orientations in conjunction with a temperature range from about 5.degree. to 40.degree. C., a rather wide range of possible refraction angles can be established.

Abstract: A random vibration generator includes a hollow tabletop for supporting equipment to be subjected to vibration, and a sinusoidal reaction-type vibration machine connected to the tabletop to produce a sinusoidal vibration of adjustable frequency and amplitude. The hollow tabletop is horizontally divided into four sections, each containing a number of projectiles such as heavy balls which roll and bounce about within the compartments in the tabletop, impacting with the floor and ceiling of the compartment and with each other in a random fashion to produce random shocks over a wide band of frequency and amplitude, and subject the equipment to every possible vibration failure mode that might occur in nature.

Abstract: The installation comprises means for subjecting a specimen-holder table to vibrations with respect to a massive support structure in two perpendicular directions, and guiding means which are independent of the vibration means. The guiding means are located between on the one hand the table and at least one connecting member and on the other hand the connecting member and the massive support structure. The connecting member is in mechanical relationship with the table and the massive structure solely by virtue of the guiding means.

Abstract: Disclosed herein is a bicycle comprising a frame, a pair of wheels supporting the frame, a sprocket fixed to one of the wheels, a drive member rotatably carried by the frame, a pair of pedals connected to the drive member, a plurality of links carried by the drive member for common rotation therewith and for pivotal movement relative thereto, a driven member, an inner guide ring, an arm supporting the inner guide ring on the frame for transverse movement relative to the rotary axis of the drive member, surfaces on each of the outer ends of the links and on the driven member and on the inner ring for mounting the driven member for common movement with the inner ring and for rotation relative thereto and for effecting rotation of the driven member in response to rotation of the drive member, a cylinder-piston arrangement on the frame for displacing the inner ring relative to the rotary axis of the drive member to vary the rate of rotation of the driven member relative to the drive member, and an endless member

Abstract: A transmission for a two-worm press having counter running worms in a worm housing, which includes: a transmission housing, an additional housing connected to the transmission housing and detachably connectable to the worm housing, a first and second transmission output shaft respectively having different length and being supported by axial bearings and drivingly connectable to the worms by means of splined coupling sleeves. The first one of the two transmission output shafts has its free end designed for positive torque transmision and extends into a correspondingly designed hub-shaped end of an additional output shaft forming part of a step-down transmission and being arranged in the transmission housing. The two transmission output shafts are supported by radial bearings spaced from each other and from the additional output shaft. Each of the two transmission output shafts has a gear keyed thereto between the radial bearings while the two gears are in mesh with each other.

Abstract: A multi-range synchronous shifting concentric gear train package having two inputs and a single output which when connected to a mechanical input and to the output of an infinitely variable drive device (shown as a hydrostatic component) powered by the same mechanical input with the input axes aligned with the center of rotation of the components of the gear package forms an all concentric multi-range synchronous shifting hydro-mechanical transmission. The combination of the same gear train package with mechanical and hydrostatic inputs in combination with right and left output planetary gear sets and a hydrostatic steer arrangement powered by the same mechanical input forms a hydromechanical steering transmission having a concentric gear train package. Gear train elements for exchanging the rotational movement of inner and outer shafts of a set of concentric shafts to permit implementation of the concentric gear train package are also disclosed in detail.

Abstract: A multi-range synchronous shifting concentric gear train package having two inputs and a single output which when connected to a mechanical input and to the output of an infinitely variable drive device (shown as a hydrostatic component) powered by the same mechanical input with the input axes aligned with the center of rotation of the components of the gear package forms an all concentric multi-range synchronous shifting hydromechanical transmission. The combination of the same gear train package with mechanical and hydrostatic inputs in combination with right and left output planetary gear sets and a hydrostatic steer arrangement powered by the same mechanical input forms a hydromechanical steering transmission having a concentric gear train package. Gear train elements for exchanging the rotational movement of inner and outer shafts of a set of concentric shafts to permit implementation of the concentric gear train package are also disclosed in detail.

Abstract: Proposed in this application is a device for adjusting ignition timing in an engine for a motor-cycle having an engine, an ignition circuit for the engine, a fluid coupling connected to the engine, a power transmission mechanism which receives driving force from the fluid coupling, and shift indicating switch which changes over in association with the power transmission mechanism to indicate a low speed drive, a high speed drive, or the neutral position, wherein the ignition timing adjusting device comprises: a plurality of ignition signal emitters, each having differing signal emission timing and producing an ignition signal output to actuate said ignition circuit when the engine is in a driven state and the vehicle is in a stopped state; and a switching element which, in accordance with change-over operation of the shift indicating switch device, controls in such a manner that any one of the output signals from the plurality of ignition signal emitters may be fed as an input into the ignition circuit.

Abstract: A punching apparatus comprising a C-shaped frame having a first movable punch disposed in one limb of the frame and a second fixed punch disposed in the other limb of the frame. The frame is pivotally mounted on a supporting base and is guided relative to the base through a cylindrical column connected to the base which is mounted in a bore of the frame, which bore extends parallel to the direction of the punches. A further support is provided for guiding the frame including a stud which is secured to the frame, which stud extends into a slot in the supporting base.

Abstract: An improved apparatus for feeding signatures from a saddle to a trimmer mechanism includes a transfer apparatus which moves each signature in turn from the saddle onto a conveyor assembly at a delivery station. The conveyor assembly includes a plurality of chains having pusher fingers which engage the trailing edges of the signatures. The pusher fingers move the signatures into the trimmer mechanism. The pusher fingers on the conveyor assembly are registered relative to a stop in the trimmer mechanism to at least partially register the signatures before they enter the trimmer mechanism. The transfer assembly, which moves the signatures from the saddle to the conveyor assembly, is effective to positively grip each signature in turn by applying a clamping force to opposite sides of the signature. These clamping forces are continuously applied to the signature from the time it leaves the saddle until it is deposited on the conveyor assembly where it is engaged by the pusher fingers.

Abstract: An apparatus for cutting a cellular plastic web emerging from a web forming machine into a plurality of predetermined lengths is described. A cutting device including a plurality of mutually spaced filaments is provided on a movable carriage slidably supported on a support stand. The filaments extend transversely of the carriage and the direction of the web emerging from the forming machine. The carriage is mounted on the stand for reciprocating sliding movement. In one direction of traverse, the carriage moves in synchronism and in the same direction as the web and simultaneously divides the web into separate lengths by means of transverse cutting devices. The filaments move alternately toward and away from the carriage to cut the web during successive synchronized movements of the carriage and web. Further, the filaments may be horizontally moved to cut profiles other than straight, vertical sections in the separate lengths of the web.

Abstract: The present specification describes and claims a method and apparatus for cutting elongate material into predetermined lengths. The apparatus comprises a cutting assembly including a cutter wheel having a number of spaced apart knife edges projecting radially outwardly in the region of its periphery. Winding means are provided for winding successive layers of material to be cut in contact with the knife and a pressure wheel forces the material onto the knife edges as the cutter wheel rotates. Press nip rollers are arranged to feed the material to the cutter wheel and both the cutter wheel and the press nip rollers are driven by the same motor.

Abstract: A method of and device for cutting blocks of foamed material, e.g. polyethylene. An endless cable of elastic wear resistant material e.g. steel, having a rough surface and a diameter of from 0.5 to 2 mm is preloaded at a force of from 5 to 30kp. The cable is operated at a speed of rotation of from 30 to 60 m/sec while the foamed material is being moved relative thereto toward the foamed material to be cut along a plane extending in a direction transverse to the direction of movement of the cable. The cable of elastic material having helically wound therearound a wear resistant wire with a diameter of from 0.1 to 0.3 mm.

Abstract: Disclosed herein is a new and unique type of circuit control for an electric guitar. Simply stated, it varies the resonant frequency of the pickup itself in addition to filtering out frequencies which are suppressed or rolled off. The mechanism by which this is brought about includes a potentiometer connected to a center tap of the coil assembly.

Abstract: Improved flat annular washer for indicating tension on associated high tensile strength bolt. Washer bears against either bolt head or nut of given radius. Washer includes means for indicating stress on washer which means is located a distance from center of washer at least equal to radius of bolt head or nut. Indicating means visibly moves when stress on washer, which is related to tensile stress on bolt, reaches a preselected level.

Abstract: There is disclosed safety apparatus for firing equipment. The apparatus includes an electrically readable memory for storing a set of values which indicate directions of firing which are safe as regards where the equipment is mounted and means for providing from indications of actual direction, an inhibition of firing at such directions which are unsafe as regards where the equipment is mounted.

Abstract: A solar energy device for producing a continuous mechanical motion to drive apparatus such as a well pump comprises a frame made of conduit sections that supports a heat collector to receive the sun's rays. Heat generated within the collector is transferred to a network of conduits therein through which an evaporatable fluid is circulated as it is heated to its vaporous state. The vaporized fluid or gas is furnished to a vapor pressure motor having a common connection to the conduit network. The motor is situated within the collector and has a movable piston operated by its own valving system that produces a continuous reciprocating action. The piston is connected to an output shaft that engages a working lever arm connected to the pump. Vapor used to operate the motor is conveyed to a condenser within the frame where it is cooled to its liquid state by water produced by the well pump which is forced through the frame.

Abstract: Disclosed is a hydraulic servomechanism including a control loop consisting of an input device, an adder-amplifier, a servovalve, a cylinder or actuator and a load operatively connected in the order named for controlling the position of the load, a position feedback loop and an acceleration feedback loop. In one embodiment of the invention, the hydraulic servomechanism further includes a feedback loop wherein an output from an accelerometer or pressure sensor for detecting a differential pressure across a piston in the cylinder and an error signal from the adder-amplifier are arithmetically processed and fed back to the adder-amplifier.

Abstract: A vacuum booster device has a casing defining two chambers partitioned by a diaphragm, a valve body connected to the diaphragm, a plunger slidably and sealingly inserted in the valve body and connected to an input rod, two valve seats formed respectively on the valve body and the plunger, and a poppet valve for engaging and disengaging with the valve seats to connect or disconnect the two chambers and to connect one of the chambers to or disconnect it from the atmosphere. One end portion of the poppet valve is fitted and retained in the inner periphery of the valve body and has an annular projection on the outer periphery of the end portion for sealingly engaging with the valve body.

Abstract: An axial-piston machine, such as an axial-piston pump or an axial-piston motor, in which the cylinder drum is in engagement with an intermediate disk which bears, in turn, upon the housing and has a spherically curved surface whose center of curvature is spaced to the side of the axis of rotation of the drum at which the pressure passage communicates with the cylinder drum.

Abstract: There is provided a method of manufacturing a string of bags from a hose-like blank. The blank is cut along a wave-shape line substantially centrally between two opposed long edges of the blank, to form two blank-halves. Welds are made adjacent selected wave-tops and wave-bottoms of the wave-shape line to form bag handles, and further welds are made perpendicularly to said wave-shape line at selected distances apart to form said string of bags. Separation lines are made adjacent said further welds to bundle a bag to be separated from the string of bags thus formed.

Abstract: Apparatus for conveying paperboard carton blanks through stations including means operative sequentially to fold the blanks about suitably scored lines into set-up tubular carton shells, including end closure flaps, about a mandrel extending along the line of blank travel, and means for rotationally transferring the set-up carton shells to carton filling and closing apparatus. Means is provided at a suitable one of the stations for applying adhesive to side flap portions of the folded blanks to retain their set-up modes as tubular carton shells.

Abstract: Method and apparatus for controlling the amount of outside air introduced into a given space being ventilated as a function of the oxygen content of the air in the space to minimize the energy expended in heating or cooling air flowing through the space while maintaining the oxygen content of the air above that required for the well-being of humans occupying said space. A fuel cell produces an electric current the magnitude of which is a function of the partial pressure of the oxygen present in the air surrounding the fuel cell. The output of the fuel cell is applied to a control circuit which applies control signals to the motor control circuit of a damper motor to admit outside air when the partial pressure of the oxygen in the occupied space falls to a predetermined minimum level and to exclude outside air and to recirculate return air when the partial pressure of the oxygen in the space rises to a certain maximum level.

Abstract: An air supply system for an operating theatre which includes a primary chamber to which filtered air is fed under pressure. A first membrane extends across the lower surface of the primary chamber and is arranged so that a high velocity downward airflow is obtained centrally of the primary chamber. The primary chamber is surrounded by a secondary chamber with a second membrane providing a permeable barrier between the two chambers and the arrangement is such that a further downward airflow is obtained from the secondary chamber, this further downward airflow surrounding the airflow issuing from the primary chamber.