Abstract: In a fluid flow machine comprising a compressor including a compressor diffuser and a turbine including an exhaust gas diffuser compressed air from boundary layers or vortex flows in the compressor diffuser, or leakage air from the compressor, is bled off and used as a driving medium for removing exhaust gas from boundary layers or vortex flows in the exhaust gas diffuser. Since the pressure of the exhaust gas to be removed from the exhaust gas diffuser is below the ambient pressure a suction has to be established to remove the desired gas from the boundary layers or vortex flows. This suction is established by an ejector or a pump which is driven by the energy of the compressed air bled from the compressor regions.

Abstract: A variable inlet vane assembly for use within the inlet area of a combustor, the vane assembly having a plurality of rotatable vanes situated within an annular-shaped opening in the inlet area of the combustor. Each vane is operated by the rotation of a crank assembly and actuator. The actuator meshes with the crank assembly through a sliding interface in order to accommodate axial and/or radial growth of the combustor with no loss in the precision of the control of air entering the combustor during rotation of the vanes. Such an arrangement substantially enhances the relight capability of the combustor.

Abstract: A spark-ignition internal combustion engine with multiple plugs is operated at an air-fuel ratio around the stoichometric under a high EGR rate higher than EGR limits for stable operation in a single spark plug ignition engine.

Abstract: A burner device adapted for use in a particulate filter arranged in an exhaust system in a diesel engine for incinerating particles collected by the filter. The device includes a mixing chamber for mixing the fuel and the air, the chamber has nozzles for generating flows of the mixture directed to the combustion chamber. Means are provided for pre-heating the air introduced into the mixing chamber. A trapping vaporizer is provided for improving the vaporization of the fuel in the mixing chamber.

Abstract: A method of controlling an internal combustion engine (14) having a power control (15) and a variable hydrostatic transmission (16, 17) including a hydraulic pump (16) driven by the internal combustion engine, and a hydraulic engine (17) connected therewith.By automatic adjustment of the power control (15) and the ratio (E) of the hydrostatic transmission (16, 17) independently of each other according to a predetermined mathematical control function (FIG. 1) which describes a desired relationship between power and rotational speed of the internal combustion engine, a specific discrete power output is delivered between zero load and full load only at an associated discrete rotational speed of the internal combustion engine.

Abstract: A fluid pressure system has a reservoir and a variable delivery pump having an inlet connected to the reservoir and an outlet. A control valve connected to a control motor and feedback line with the feedback line adapted to control the fluid flow to and from the control motor to vary the pump displacement, to maintain the pressure at the pump outlet at a difference above the pressure in the feedback line. A control valve is adapted to control the fluid flow between the outlet, the load motor and the reservoir. The control valve is adapted to control the fluid flow between the load motor, the reservoir and a control line and is operable in a neutral position to block off the pump outlet from the load motor and to connect said control line to the reservoir. The control valve is operable to another position which connects said load motor to the control line before the pump outlet is connected to the load motor.

Abstract: A system for achieving temporary increase in performance in a turbo-charged combustion engine comprises a microprocessor in which there are stored a value of the maximum permissible charge pressure at constant load and a higher value of the maximum permissible charge pressure at increasing load. The processor senses the charge pressure and is connected to means which sense the rate of opening of the throttle. At a certain rate of opening, the processor permits an increase in the charge pressure to the higher pressure and thereafter effects timed reduction of the charge pressure to the maximum permissible pressure at constant load.

Abstract: An engine having a turbo-supercharger comprised of a blower in the intake passage and an exhaust gas turbine in the exhaust passage. A charging pressure limiting device includes a pressure relief passage in the intake system or a turbine bypass passage in the exhaust system which is provided with a control valve. A control circuit is provided for limiting the peak charging pressure. The control circuit includes a limit signal generating circuit for providing a limit signal which decreases in response to an increase in the engine speed under a high speed range, a comparator for comparing the limit signal with the actual charging pressure signal and producing a control signal when the charging pressure signal reaches or exceeds the limit signal so that the charging pressure does not exceed the limit value which decreases in response to an increase in the engine speed under a high speed range.

Abstract: Working fluids for use with the Rankine cycle comprising 5 to 50% by weight of tetrafluoromethane, 40 to 95% by weight of trifluoromethane and 0 to 10% by weight of monochlorodifluoromethane.

Abstract: The disclosure relates to refrigeration through magnetizing and demagnitizing a body by rotating it within a magnetic field. Internal and external heat exchange fluids and in one embodiment, a regenerator, are used.

Abstract: A method and apparatus for rapidly chilling a cool pack associated with a refrigeration system wherein slush-like medium is introduced into the pack in a first step and frozen to a substantially solid state in a second step.

Abstract: A vehicle mounted refrigerator includes an apparatus for levelling the condenser coils including a support frame mounted in a generally horizontal plane and pivotable about generally orthogonal axis with electrically powered levelling support jacks activated by level sensing switches for levelling the frame on which the condenser coils of the refrigerator are mounted. An alternate embodiment includes hand operated jacks for levelling the condenser coils.

Abstract: A thermal energy compression system wherein the refrigerant in a heat pump or air-conditioner is compressed by thermal energy in the compression system rather than by work in a standard compressor. The compression uses an intermittent compression process with a solid absorbent. The vapor is absorbed by an absorbent at relatively low temperature and ejected as the absorbent temperature is raised and a set of one way valves limits flow to one direction so as to improve heat transfer requirements, to allow for molecular sieve-refrigerant matching, minimizing non-producing mass, solving thermal fatigue and shock problems, and use of the system in parallel with a standard compressor, automobile air-conditioning applications and truck refrigeration applications.

Abstract: An air conditioner includes a plurality of refrigerant compressors, a plurality of ventilating fans and a cooling/warming water pump which is controlled by both a memory and a contact-less control unit in accordance with an outdoor temperature and a refrigerant temperature which are sensed by associated temperature sensors. Alternatively, the control unit may be connected to both protective devices disposed on the fans, the compressors, the pump, etc. and further connected to a digital indicator which indicates the operating status of the air conditioner.

Abstract: A heat pump with a compressor arrangement whose condenser forms a heater for water, and whose evaporator is arranged to be heated by air which by means of a fan in a fan space is blown through the evaporator. An air path for ambient air or an air pass for room air is connected alternatively to the fan space. A control means is arranged between the fan space and two air passes for selective connection of one or the other air pass to the fan space, and with the control means in a first position, the fan is arranged to blow air through an air path with ambient air and through the evaporator for water heating, and with the control means set in another position, the fan blows air through another air path with room air and through the evaporator.

Abstract: A rotary compressor formed with an unloading port maintaining a working space in communication with a suction chamber and opened and closed by a valve, to vary the capacity of the compressor. The internal pressure of the working space is sensed in a compression stroke or this pressure and the pressure of a fluid drawn by suction are both sensed, so as to open and close the valve based on the sensed internal pressure of the working space or the pressure differential between the internal pressure of the working space and the pressure of the fluid drawn by suction, to give suitable hysteresis to the operation characteristics of the on-off valve to stabilize the operation of the on-off valve.

Abstract: An arrangement and method of controlling optimum chilled water temperature supplied to a process by a pump, the water being chilled by coolant in a coolant cycle having a compressor and a load valve, comprises first and second sensors for sensing a supply and a return temperature to and from the process. A value is obtained for the amount of work done by the pump and the compressor with that value as well as the supply and return temperature values being supplied to a supervisory control. The supervisory control operates to generate a reference temperature which is a function of the supply temperature but which is either above or below the supply temperature depending on a ratio between the difference in work and a change in the difference between the supply and return temperatures. When the ratio is about zero this indicates the difference between supply and return temperature is at an optimum and the reference temperature is the same as the supply temperature.

Abstract: A pulse controlled refrigeration expansion valve and method of controlling the valve is disclosed. The valve is preferably an on/off (open/closed) direct controlled solenoid valve. The valve is periodically energized (opened) and de-energized (closed) in response to a refrigeration system parameter (e.g., superheat) such that the ratio of energization time/de-energization time during each period of operation of the valve is varied in response to the system parameter(s) and such that the on/off solenoid valve functions as a modulated refrigerant flow control expansion valve.

Abstract: A motor-driven compressor condenser group for equipment actuating cooling-cycles, such as for example cooling apparatuses and heat pumps, enclosed in a single container.The cooling fluid of the heat-exchanger connected to the condenser passing to and from the container is to be used in domestic cooling systems to heat water.

Abstract: A bulkhead for a cargo carrying vehicle and method of constructing same is the subject of the present invention. First and second uniform extruded sections are provided, each of which presents alternating web portions and open areas sandwiched between generally planar surfaces. Plate connecting means is interposed between the two extruded sections and presents first and second connecting surfaces which are aligned with the first and second planar surfaces. First and second channel means disposed across the ends of the extruded sections place each of the open areas in closed communication with an adjacent area. The open areas may be utilized to house a refrigerant conduit and a freezable media so as to convert the bulkhead into a self-contained cold plate. Alternatively, a heating element may be placed in the open areas so as to convert the bulkhead to a hot plate. The aforedescribed assembly is disposed on one side of an A-frame which divides the cargo area into left and right sections.

Abstract: A cooling suit system comprises a suit which is adapted to be worn by a person and which has a cooling media flow conduit therein for circulating a cooling media therethrough. A heat exchanger is associated with the suit and is advantageously adapted to be carried on the back of the wearer and it includes an inlet to the heat exchanger which is connected from the flow conduit into an insert of elastic material arranged within the housing of the heat exchanger. An outlet connects the lower end of the insert to the cooling media flow conduit downstream of the inlet. The insert is filled with a cooling media in the form of meltable solid pieces of ice and it is elastically constructed so that it tightly engages around the ice and may compress with the ice in its liquid form from the thawing of the ice.

Abstract: An apparatus comprising a rotating substrate holder is provided. The rotating substrate holder is hollow and adapted to receive liquid gas such as nitrogen to cool the substrate to cryogenic temperatures. The novel substrate holder is supported inside of a vacuum chamber by a thin wall tube which is sealed with a liquid rotating seal at the point where it passes completely through the top wall of the vacuum chamber. The novel thin wall tube support provides access to the hollow substrate holder from outside the vacuum chamber and provides temperature isolation of the liquid in the substrate holder so that the liquid rotating seals are maintained at operable elevated temperatures.

Abstract: An ice cube maker in which a generally vertically disposed array of fins including first fins extending laterally outwardly from one side of a central vertical plane and second fins extending outwardly from the other side of the plane is disposed over an open top tank to which a predetermined volume of water supplied at the beginning of an ice-making operation in the course of which water from the tank is fed to a distributor over the tank so as to fall downwardly into the fins which are cooled to form ice. When water in the tank reaches a predetermined low level the ice is harvested by heating the fins to permit the ice to falls into a bin below the array. In response to movement of ice into the bin a new cycle is initiated.

Abstract: An apparatus for reducing the temperature of articles to the cryogenic state in reducing the temperature of embryos at a controlled and predetermined rate is disclosed comprised of a housing defining an insulated cooling chamber employed in association with support means for removably suspending the embryos within a chamber. A gaseous medium, such as, air circulates along a closed path through the chamber so that the embryos are disposed in its path and a heat exchanger including a heat transfer medium is positioned in the flow path of the gaseous medium together with a temperature sensor so that the rate of cooling may be programmed and regulated automatically by correlation of the temperature sensor with the heat exchange medium.

Abstract: A refrigerator has a first cooling device i.e. a direct cooling evaporator and a second cooling device i.e. an indirect cooling device to cool a circulating air in a refrigerator box, in which a cold storage member is attached to the direct cooling evaporator whereby when the indirect cooling evaporator is heated for defrosting, the temperature rise of the direct cooling evaporator due to a refrigerant gas flowed from the indirect cooling evaporator back into the direct cooling evaporator is prevented.

Abstract: Disclosed is a golf bag cooler kit for carrying and cooling canned beverages. A belt and mounting plate assembly is adjusted and tightened on a golf bag by means of belt straps. The cooler has compartments for receiving canned beverages. The cooler has a spring-clip assembly that is releasably engageable with the mounting plate to thereby mount the cooler on the golf bag. The spring-clip assembly is releasably locked together by cooperating interdigitation means.

Abstract: A multiple-chamber cooling device particularly useful in a dilution refrigerator in which a working liquid is passed successively through a plurality of chambers in each of which a fraction of the working liquid is allowed to evaporate to cool the remaining working liquid. The cooling device comprises a common body member of low thermal conductivity formed with a plurality of spaced bores each defining one of the chambers, the outlet end of each chamber bore being connected by a passageway to the inlet end of the adjacent bore for passing the working liquid from one to the next chamber bore as a fraction of the working liquid is evaporated to cool the remainder.

Abstract: A hollow precious metal earring post that has a notch in the wall thereof to receive a clutch is disclosed, which post has a solid gold solder metal interior from the radiused end to a point beyond the notch to rigify and support the post along the notched area.

Abstract: An attachment for use with multi-feed circular knitting machines of the type having a rotary needle cylinder and having yarn striper boxes at the feeds thereof. The boxes serving to change and to cut and clamp the yarns fed to and knit by the machine during the making thereon of coursewise striped fabric. The yarn changing operation resulting in undesirably long unknit terminal portions of the changed yarns extending inwardly from the inner side of the tubular fabric being made. The terminal portions of the yarns having cut ends. The attachment comprising a device having yarn clipping means disposed within the tubular fabric and rotating in unison with the needle cylinder to cut and to shorten the terminal portions of the changed yarns as the tubular fabric continues to be made, whereby the yarns are cut firstly by the striper boxes and secondly by the yarn clipping means.

Abstract: A mixture of air and solvent vapor is sucked from a distillation vessel before or while the door closing the discharge opening of the distillation vessel is opened and the mixture is purified and then exhausted as exhaust air. In the apparatus, the distillation vessel is connected by conduits and controllable valves to the drying fan, by which the solvent-containing air that has been sucked is exhausted into the open through a purifying and/or recovering system.

Abstract: A pivotally mounted coupling guard, extending over a ball engaging socket of a trailer hitch to preclude disengagement of the socket from the ball, is locked in place to deter unauthorized disengagement of the socket from the ball and theft of the attached trailer. A lock module penetrably receives and locks therein essentially all of the extending ends of both the pivot pin and the retaining pin of the coupling guard to preclude unauthorized pivotal movement of the coupling guard.

Abstract: At a swiveling stirrup lock, particularly for a two-wheel vehicle with a swiveling stirrup that can be swiveled through the spokes, the swiveling stirrup is supported in a swivel hub to be rotatable about its longitudinal axis. The swivel hub is supported to be swingable about a swivel axis on a pivot bearing which is to be attached at the bicycle frame. At least in the driving position, the swiveling stirrup is secured by engagement of a rotation securing element, installed at the swiveling stirrup, into a rotation securing element mounting of the pivot bearing. This engagement can be produced or released by rotating the swiveling stirrup into or out of a rotation securing position. The rotation securing element is installed according to the invention at the swiveling stirrup in the region of its outlet from the swivel hub outside the latter.

Abstract: A remote control door-lock device connected to front and rear door lock devices for an automotive vehicle used to lock/unlock the front and rear vehicle doors from a position near a driver seat comprises one or two guide plates having a slot formed therein and one or two actuation members having projection pins on one side thereof and an opening on the other side thereof. The guide plates are controlled by a remote control lever via a cable, and the slots thereof engage the pins so that the guide plates control the position of the actuation members, but with some mutual free travel. The actuation members also engage with front and rear door lock members, usable by passengers, so that if the remote control lever is actuated, the door lock members are in turn actuated to lock the respective doors, and to disable the door lock members. That is, the door lock members can be actuated either directly or by the remote control lever.

Abstract: A door lock comprises a reciprocatingly movable lock bolt and means for locking the lock bolt in a protruding position, for keeping the lock bolt in a withdrawn position and for operating the lock bolt either with a handle or the like or with a key operated mechanism. There is also a lock function selector for selecting a desired type of functional capacity for the lock. The lock function selector has three different setting positions, of which each determines a specific type of functional capacity for the lock. There is a setting member, preferably in a hidden position when the lock is mounted in a door, by means of which setting member the setting of the lock function selector can be restricted in order to further determine the types of function obtainable by the lock.

Abstract: Apparatus and method for forming a peripheral skirt on a workpiece of metal or other ductile material with reduced pleating of its peripheral edge. The concentric mating male and female dies of the prior art are provided, and in addition at least one drawbar concentric with, outside of, and generally beside the male die guides the outer periphery of the workpiece as the dies are urged together, preventing the outer margin of the workpiece from being folded under and propagating pleats. The drawbars also assist in clamping the outer margin of the workpiece between the dies when the central portion of the workpiece is to be expanded by the application of fluid forming pressure.

Abstract: This invention provides an indirect metal extrusion method, in which free die system is adopted. A die (8) of two-stepped structure is capable of removing shell or outer layer of a billet simultaneously at the time of extrusion, and eliminating the container cleaning cycle after the extrusion. Besides, a shear support (3), an independent body of the container (2), is disposed on the nearer side of the container (2) to an extrusion ram (4), so that discard integrally clung to the die (8) may be served after finishing of an extrusion stroke off the die (8) which is rested on the shear support (3) by means of a shear (14) or a shearing apparatus. This method enables shortening of the extrusion cycle and eliminating damage to principal structure of the extruder.

Abstract: A gripping head (2) of a sheet stretcher has a centering device (4) for centering a sheet (1) to be stretched in the middle of the gripping head (2) before the sheet is gripped and stretched. The centering device comprises two centering arms (5) which move with their edges towards the longitudinal sides of the sheet and are synchronously displaced in opposite directions and at right angles to the axis of stretching. In order to facilitate optimum gripping of the sheet automatically, guide rods (9) having engaging members (10) sliding thereon are provided on the centering arms (5) and extend parallel to the axis of stretching. The ends of the engaging members (10) have stops (14), against which the front end of the sheet (1) bears when fully inserted. A distance-measuring device (18), is provided on the centering arm (5) and has a cable drum (22) and a potentiometer (20) on the same shaft (21). The end of the cable is secured to the engaging member ( 10).

Abstract: A crimping tool having an adjustable anvil and a crimp pin movable toward the anvil has means for limiting the movement of the crimp pin toward the anvil.

Abstract: A rolling wobble press includes a planar surface which is perpendicular to a first axis and a cone which rolls on the planar surface as the cone revolves around the first axis. The axis around which the cone rotates as it rolls intersects the first axis at the same point that the first axis intersects the planar surface so that under ordinary circumstances, there is no slippage between the cone and the planar surface. The cone is driven by a drive shaft which is coaxial with the first axis. The drive shaft is connected to the cone via a crank having an arm oriented obliquely thereto in which arm the cone is rotatably journaled.In accordance with one embodiment of the press, the press is used to drive a plurality of punches in a riveting machine.

Abstract: In an exemplary embodiment, a measuring cell is disposed in an outer tube. A chamber in the outer tube adjacent the measuring cell can be directly connected via an opening to the liquid in a liquid vessel whose pressure is to be measured. In order to also be able to calibrate the pressure transducer at any time in the liquid vessel, an elastic container is inventively disposed in the chamber, the container being connected to a connecting line likewise lying in the outer tube for the purpose of filling and emptying. In its filled state, the container closes the opening of the chamber without interrupting the connection between a fluid line used for calibration and the measuring cell.

Abstract: The present invention relates to an apparatus suitable for accomplishing a roll testing method. The object of the present invention is accomplished by hot rolling steel strip under the specified rolling condition using small size testing apparatus having about a tenth size of the actual rolling mill and good reciprocity like said rolling mill. The wear state (roughness), or new state, of the roll surface is estimated by a known type of surface roughness meter from the roll surface generated after hot-rolling the stell strip by the small size testing apparatus of the present invention. Said testing apparatus has the structure in which both the diameter of the rolls and the circumferential speed of the rolls are about a tenth of those of actual rolling mill and the number of the contact times (contact interval) between the rolls and the stell strip per the rolling time is the same to that of the actual rolling mill.

Abstract: A method and apparatus for testing containers for pressure leak characteristics is disclosed. The arrangement includes monitoring the fluid pressure in a container supplied with test fluid at two different time intervals, with the monitored difference being compared with a predetermined acceptable value of container pressure loss and a signal generated to either accept or reject the tested container. To facilitate a continuous updating of the calibration of the acceptable pressure loss, a digital computer controlled arrangement is provided for adjusting the predetermined acceptable pressure loss value as a function of the monitored difference in the pressures for containers previously tested.

Abstract: A portable leak detector is disclosed for use with, say, helium as a tracer gas. The leak detector includes an improved separation chamber, an air pump for pumping the sample gas, a high vacuum spectrometer, and a small and lightweight evacuation pump. The separation chamber is formed by an air-tight enclosure which has an inlet duct, an outlet duct, and a tubular separation membrane extending between manifolds connected to the ducts. Gas samples are collected by a gas sampling probe and pumped by an air pump into the inlet duct of the separation chamber, through multiple parallel tubes of the tubular membrane material, and out the outlet duct of the separation chamber where it is exhausted. The multiple tubes are formed of a selectively-permeable membrane material such as Tefzel which permits the rapid diffusion of helium therethrough but which has relatively low permeability for other gases contained in the gas sample.

Abstract: Methods for determining rate of fuel flow to a combustion engine is disclosed. The fuel flow rate determination is made by measuring a pertubation in air-to-fuel-flow ratio to the engine, or in the volumetric concentration of a gaseous test species in the exhaust, after adding a known amount of a test substance to the air flow intake to the engine, or to the exhaust from the engine, respectively. The desired fuel flow rate is calculated from the measured parameters.

Abstract: The present invention provides a fuel consumption testing arrangement for use in the analysis of internal combustion engines having fuel carburation device, including a fuel source, a constant rate fuel pump communicating with the fuel source to receive fuel from the fuel source and deliver a selected rate of fuel, fuel pressure regulator to receive fuel from the fuel pump and supply the fuel at a selected pressure, a fuel flow transducer device communicating with the outlet of the fuel pressure regulator to measure the rate of flow of fuel from the fuel pressure regulator and having an outlet including a connector to connect the supply from the flow transducer to the carburetor of the internal combustion engine to be tested, a source of electrical power to deliver a smooth flow of current to drive the fuel pump, speedometer to sense the speed of rotation of the internal combustion engine under test, and a computation device to inter-relate the speed of rotation of the internal combustion engine under test an

Abstract: A vortex shedding device for use in measuring air flow rate into an internal combustion engine includes a duct provided therein with an element for forming vortices in air flowing through the duct. A pair of hot wires is located in the duct which are alternately exposed to vortices generated by the vortex forming element. The hot wires are associated with an electric circuit which detects variations in the resistances of the hot wires and determines the frequency at which vortices are generated in air flowing past the vortex forming element. The electric circuit contains a vortex detector for each of the hot wires so that even if one of the hot wires is broken, a pulse signal is still provided during steady operation of the engine.

Abstract: The device comprises an annular adaptor having a bottom provided with an opening so as to permit sliding the adaptor on the housing of the kilometer recorder and including a peripheral axial collar. The collar is provided with an assembling groove which receives a corresponding rib on a transparent window. An inner shoulder clamps the dial between these two elements. The window and the collar of the adaptor have shapes and sizes which may vary in accordance with the shapes and sizes of the dial.

Abstract: A force measuring system is provided in which a force sensitive element (51) includes a movable capacitor plate (21) located between two fixed capacitor plates (19, 20). A pair of jewel bearings (52) are mounted to a support casting (55) and provides support for a force sensitive element (51). The support casting (55) also serves as a support for a hybrid integrated circuit (68) which, in turn, forms a support substrate for one of the fixed plates (19). A second fixed plate (20) may be mounted on the casting (55) via a substrate (69). The hybrid integrated circuit (68) is therefore in close proximity to a capacitor element (19-21). The hybrid circuit (68) provides output power to a torquer coil (37) which centers the force sensitive element (51), with current provided to the torquer coil (37) being indicative of force exerted on the force sensitive element (51).

Abstract: Apparatus for picking-up and analyzing emitted accoustic and ultrasonic signals by means of a piezoelectric pick-up element connected to an amplifier with high input resistance, the output of the amplifier being connected for further evaluation to selective circuits and to an evaluation device. The piezoelectric pick-up element is situated in a casing, said casing being fixed to a hollow body being tested as by a strap encompassing at least partly both the casing and the tested hollow body.

Abstract: A method for localizing and analyzing sound emissions, wherein the position of the sound emission source is determined by incoming sound pulses at various measuring locations. The arrival time of a pulse or of a pulse characteristic is measured in three or more adjacent portions of each measuring location whose width is smaller than the expected sound field diameter. From this, the propagation time difference for the portion of each measuring location is determined and the sound arrival direction is determined from these propagation time difference values for each measuring location. Subsequently, the position of the sound emission source is determined from these direction values and the position coordinates of the measuring locations.The device for carrying out this method has three or more separate converter elements (1) for each receiver measurement head (E) whose total width is smaller than the expected sound field diameter.