Showing papers on "Cavity wall published in 1986"

Method for manufacturing a mold for producing molded parts of large size and of a composite material

Abstract: A molding cavity wall (10) is made in a plurality of parts of a cheap material having a high thermal conductivity, for example a thin metal sheet (10), at least one heating device (11) is applied on the wall in direct thermal exchange relation to the external surface of the wall (10), and a thermal insulator constituted by a foam (12) of highly rigid resin is applied to the wall (10) in uniform pressure transmitting relation to said wall

Receptacle and plug assembly

Abstract: An electrical connector for interconnecting a plurality of signals comprises an assembly of a plug and receptacle. The plug includes a housing member having a cavity at its forward end defined by a peripheral wall and a cavity wall, and a rear wall. The housing further includes contact receiving apertures extending between the cavity wall and the rear wall. An insert is locked in place in the forward cavity, the adjacent wall of the insert having standoff feet to define a gap between the cavity wall and insert wall. The insert has apertures in alignment with the apertures in the housing. The apertures within the insert include a shoulder facing the rear wall of the insert. A contact insertable into the apertures in the housing and insert has a lance which is locatable in the gap between the cavity wall and insert wall to lock the contact in place. The receptacle has a right-angled configuration having pins extending from a mounting face for interconnection to a printed circuit board. A second face is mountable to a bulkhead and has three rows of pins mounted in a cavity recessed from the second mounting face for interconnection to a matable plug having socket contacts. The contacts within the receptacle are disposed in three tiers, the contacts being bent around mandrels to form the right-angled bend. Below the mandrels is a contact locating plate having contact receiving slots in line with the contacts. The upper and lower row of contacts are laterally aligned with each other and with a first contact receiving slot. The first slot has two widths, and has a rib extending down along the edges of the slot. When the contacts are placed in the slot, the ribs interferingly hold the contacts in place, the second row of terminals is also aligned with a contact receiving slot having ribs for interferingly locking the second row of terminals in place.

Some properties of microwave resonant cavities relevant to pulse‐compression power amplification

Abstract: One method of generating short, high‐power microwave pulses is to store rf energy in a resonant cavity over a relatively long fill time and extract it rapidly. With this pulse compression technique power gain roughly equal to the ratio of fill time to extraction time can be obtained. During the filling of a resonant cavity some of the energy is lost in heating the cavity walls, and some will generally be reflected at the input coupling of the cavity. In this paper, we discuss the time dependence of the stored energy and related quantities and the way in which it depends on the coupling of the source to the cavity.

Beam Absorption Mechanism In Laser Welding

Abstract: Mechanism of laser beam absorption was analyzed in key hole welding of thin plate and deep penetration welding of thick plate on the basis of the two-dimensional cavity model where beam is absorbed by cavity wall and ionized metal vapor. The beam absorptivity of the cavity wall A and the absorption coefficient of the plasma u are approximately 50 % and 1- 1.5 cm-1, respectively. In key hole welding of thin plate, laser beam is absorbed predominantly by the liquid cavity wall and the cavity shape is self-controlled so as to absorb the energy required for bead formation. In deep penetration welding of thick plate, laser power is absorbed mainly by plasma where the self-controlling is less effective, and hence excess energy absorbed at low welding speeds is w'sted to widen the bead with little increase in penetration depth. In vacuum of 10-3-10-4 torr, u decreases down to approximately 0.5 cm-1, providing large penetration depth.

Method for sand casting varying thickness articles

Abstract: A permanent casting mold has its casting cavity coated with a sand liner of varying thickness. The liner is thicker where the cast article section is thinner and the liner is thinner where the cast article section is thicker so as to permit the thicker sections to cool faster while the thinner sections cool slower. The different thicknesses of the liner are correlated so that the respective sections of the article are sufficiently cooled at about the same time for removal of the article from the mold. The mold is a cope and drag-type flask mold whose casting cavity halves are oversized relative to the cast article. The sand liner is formed therein by temporarily positioning a pattern within the permanent casting cavity halves and sand filling the space between the pattern and cavity wall. The exterior surface of the pattern corresponds to the cast surface of the article. Thus, the thicknesses of the different portions of the liner are determined by the amount that the corresponding portions of the casting cavity are oversized. A vacuum system opening into the casting cavity, when the cope and drag are closed together for casting, enables rapid filling of the sand-lined cavity with molten metal, wherein the entire casting process, including cooling of the cast article for removal, is performed rapidly.

Vented casting molds and process of making the same

Abstract: The mold body contains a cavity and at least one vent passage for venting gas from the cavity through the body. The vent passage has a portion of predetermined regular shape extending part-way through the cavity wall defining at one end an inlet portion opening into a portion of the cavity with a substantially greater resistance than the cavity to penetration therein of casting material. The vent passage further has an outlet portion formed by an irregular crack in the mold body extending from an inner end exposed to the inlet portion through the mold body, the crack having one of its transverse cross-section dimensions short enough to prevent leakage of casting material therethrough. The mold is made by forming a partially bonded ceramic material containing a casting cavity and incorporating in a wall of the cavity a vent pattern of a shape to mold the portion of predetermined regular shape of the vent passage. The mold is heated to a temperature below the melting point temperature of the pattern for a time sufficient so that heat expansion of the pattern causes the crack part of the vent passage to form. The mold is then heated to higher temperatures to cause the vent pattern to volatilize and escape from the mold body.

Sealed plug for a printed circuit board receptacle

Abstract: A plug assembly comprises a housing member having a cavity at its forward end defined by a peripheral wall and a cavity wall, and a rear wall. The housing further includes contact receiving apertures extending between the cavity wall and the rear wall. An insert is locked in place in the forward cavity, the adjacent wall of the insert having standoff feet to define a gap between the cavity wall and insert wall. The insert has apertures in alignment with the apertures in the housing. The apertures within the insert include a shoulder facing the rear wall of the insert. A contact insertable into the apertures in the housing and insert has a lance which is locatable in the gap between the cavity wall and insert wall to lock the contact in place.

Effect of Composition and Curing Type of Composite on Adaptation to Dentin Cavity Wall

Abstract: Adaptation to dentin cavity wall of three marketed and eight experimental composites was investigated by measuring polymerization contraction in cylindrical dentin cavities and by SEM observation. The cavity adaptation of light cured composites was always inferior to that of the chemically cured composite and, in the experimental composites, the optimum filler content was obtained.These facts indicate that cavity adaptation is affected significantly by the flow of the composites from the free surface into the cavity during polymerization.

Albedo Analytical Method for Multi-Scattered Neutron Flux Calculation in Cavity

Abstract: A simple formula which describes multi-scattered neutron flux in a spherical cavity was derived based on the albedo concept. The formura treats a neutron source which has an arbitrary energy-angle distribution and is placed at any point in the cavity. The derived formula was applied to the estimation of neutron fluxes in two cavities, i. e. a spherical concrete cell with a 14-MeV neutron source at the center and the “YAYOI” reactor cavity with a pencil beam of reactor neutrons. The results of the analytical formula agreed very well with the reference data in the both problems. It was concluded that the formula is applicable to estimate the neutron fluxes in a spherical cell except for special cases that tangential source neutrons are incident to the cavity wall.

Triangular antenna array for microwave oven

Abstract: An excitation system structurally compatible with a low profile streamlined microwave oven appliance configuration, comprising a generally planar antenna member disposed between the bottom wall and a support shelf centered laterally in the oven cavity and extending over a substantial portion of the bottom wall. An open peripheral region is defined between the front, back, side and bottom oven cavity walls and the peripheral edge of the antenna member. A plurality of radiating apertures are formed in the antenna member and arranged in a triangular fashion such that straight lines connecting the centers of any three closely adjacent apertures intersect to define an equilateral triangle. Microwave energy is coupled from the magnetron to the center point of the antenna member, whereby microwave energy radiates from the apertures in the antenna member to heat items placed on a support shelf from below and energy propagates between the antenna member and the bottom cavity wall to the periphery of the antenna member from which it is radiated through the peripheral region into the interior of the cavity and reflected by the front, back, side and top cavity walls to the heat items on support shelf from above.

Multiple heat pipes for linear beam tubes having common coolant and vaporizing surface area enhancement

Abstract: A linear beam tube has multiple heat pipes formed integrally in the cavity wall between the beam collector and external air cooling fins. The heat pipes use sintered copper pellets on the walls of the pipes as wicks to facilitate the return flow of liquid condensed at the fins. Circumferential channels connect the heat pipes at each end to reduce vapor lock effects. Vapor surface area enhancement rods are used at the heat source to increase the transfer rates of heat into the fluid.

Lintels and fittings therefor

Abstract: A lintel having a front portion 16 for extending through the outer skin 12 of a cavity wall and a portion 18 extending upwardly and rearwardly therefrom to bridge a cavity is further provided with an end wall 20 to restrain the discharge of water. This wall 20 may be a separate member having formations such as double walls 26 defining channels 28, or projections for engaging the edges of the lintel. For accommodating different lintel shapes the wall 20 may be flexible, e.g. due to flexing formations 30, and/or provide a plurality of alternative channels. The wall may also provide for ventilation and drainage, e.g. having a weephole 40, a grille 34 and a baffle 36.

Whetstone polymer composite material for melting and crushing machine and manufacture thereof

Abstract: PURPOSE:To improve the pressure resistance, wear resistance, durability and heat resistance of whetstone polymer composite material for a melting and crushing machine by growing and filling thermal plastic polymer in an inner vacant cavity from its wall between porous vitrified grinding particles within the specific percentage range of a total cavity volume. CONSTITUTION:The connected vacant cavity 2 between porous vitrified grinding particles 1 for a melting and crushing machine is impregnated with thermal plastic material monomer along its wall. The monomer so impregnated is polymerized at that position by using heat energy and thermal plastic polymer 3 is made to grow and filled. Then, surface finish is carried out to make the polymer of whetstone for the melting and crushing machine. In this instance, the polymer 3 is made to grow and filled from the vacant cavity wall within a range of 30-60% of the total volume of the vacant cavity 2, and 70-40% of the said cavity 2 remains to keeps its volume percentage at 0.09-0.21.

Wall ventilator and cavity wall ventilation system

Abstract: The wall ventilator comprises a hollow ventilating member through which air can flow, and a plurality of baffles 8 disposed within the ventilating member and adapted to alter the direction of air flow through the ventilating member. The baffles are arranged to divide the air flow within the ventilating member into a plurality of ventilation paths, so that air cannot flow through the ventilating member without flowing through one of the ventilating paths. A cavity wall ventilation system is also described and comprises outer and inner walls having a wall ventilator disposed in at least one of the walls. A ventilating duct, attached to the ventilator, provides an air flow from the outer wall to the inner wall. The baffles separate entrained dust and water from the air.

Laboratory measurement of thermal transmittance of several masonry wall systems

Abstract: Thermal transmittance (U-value) for several masonry wall systems was measured in a guarded hot box in accordance with ASTM test method C236. The wall systems are block walls with and without various core insulations, cavity walls with and without cavity and core insulation, special block walls with factory-installed insulation inserts, and walls with surface mounted, rigid insulation boards. The measured U-values of the wall systems were then compared with calculated U-values based on ASHRAE procedures. In general, there was disagreement between the calculated U-values and the measured U-values. It is believed that multidimensional heat flow and the lack of knowledge of accurate values for thermal conductivities of the components contribute to the disagreement.

Reduced flash molding

Abstract: A mold used for forming an elastomeric article such as a tire under heat and pressure is provided with small grooves at selected locations along the internal cavity walls to reduce or eliminate flash which customarily forms at these locations. Specifically, grooves are provided at the structural interfaces of replaceable mold components, such as tread and bead rings with cavity wall portions of the mold sections. The grooves operate to trap or collect elastomeric material extruded into the interfaces and provide a seal-like barrier to further flash.

High-power klystron

Abstract: PURPOSE:To make it possible to measure the tuning curve ar the middle cavity beforehand by equipping a coaxial circuit with a loop for measuring the tuning frequency mounted on the external wall of a cavity through a side tube aud a bellows and specifying the relationships between the inner diameter of the side tube and the height of the middle cavity and between the length and the inner diameter of the side tube. CONSTITUTION:The cavity wall 13 is connected with one end of a side tube 19 in which a coaxial line 20 arranged to be freely displaceable in its axial direction is inserted so as not to contact with the side tube. At this time, there are relationships d=(1/3-1/5)H between the inner diameter d of the side tube 19 and the height H of the cavity and besides l>5d between the length l and the inner diameter d of the side tube. An end part of the coaxial line 20 is connected with a loop 21 which protrudes slightly into the interal wall part of the cavity and thereby the coaxial line is coupled with the cavity. The tuning curve of each cavity is measurable by applying high frequency power from the loop 21 to within the cavity under this condition and observing a sweep reflected waveform generated within the cavity.

Method for producing annular articles having at least two layers

Abstract: For the production of annular objects (110) which at least one layer (112) made of leather and one with this layer (112) connected layer (111) made of plastic, arranges the layer of leather in the form of a blank (112) finally its edges (114) within the cavity one Shape. The blank (112) in the mold cavity with the art fabric is connected by inserting plastic into the mold cavity in a flowable or solid state and can penetrate into the blank (112). The cut (112) is given by suction on the wall of the mold cavity and through the plastic introduced into the mold cavity annular shape that holds edges (114) of the blank (112) one by suction against the wall of the mold cavity Wall of the mold cavity firmly and the plastic (111) forms one around the edges (114) of the blank (112) so that the outer surface of the blank (112) with the outer surface of the Plastic (111) runs flush.

Water‐gun cavity collapse in a compressible liquid

Abstract: The velocity of the cavity wall is all important in the calculation of the far‐field signature for a water gun firing in the ocean. I use a method of successive approximation to solve Herring’s energy equation for the collapse of a spherical cavity in a compressible liquid. The velocity of the collapse of the cavity wall depends upon the compressibility of the liquid, the amount of residual gas in the cavity, and the amount of acoustic radiation. The compressibility of the liquid has a significant effect on cavity velocity, but it has very little effect on the collapse period. The maximum value of the cavity velocity determines the peak magnitude of the far‐field pressure signature; the pressure signature depends strongly on the amount and rate of residual gas compression. The results from solving Herring’s equation agreed satisfactorily with a numerical solution of the fluid equations of motion. This solution to Herring’s equation includes the compressibility of the liquid, the residual gas compression, ...

Direct injection type engine

Abstract: PURPOSE:To suppress the deterioration of the wall surface of a cavity by forming the effective sectional surface of a plurality of injection holes formed onto one fuel injection nozzle so as to be larger as the cavity wall surface in the related injection region becomes longer, thus dissolving the problem of combustion performance such as delay of ignition. CONSTITUTION:Each injection hole is formed so that the center of the injection flow supplied from the injection hole collides at the depth level position nearly equal from the top surface of a piston 1 for the wall surface of a cavity 2. The peripheral length of the wall surface of the cavity 2 is made longer at the position closer to the nozzle top edge part 2a. Further, the diameter of the injection hole in the region having the longer peripheral length is made larger. Therefore, the adhering fuel is scattered, and the adhering fuel quantity per area of the wall surface of the cavity 2 is made relatively small. Therefore, the problem of the combustion performance such as delay of ignition is dissolved, and the deterioration of the wall surface of the cavity 2 can be suppressed.

Manufacture of multi-cavity klystron

Abstract: PURPOSE:To remove unevennesses from on the sliding surface of a sliding element and then remove the unstability of the frequency characteristics of a multi-cavity klystron by brazing the magnetic body of the magnetic pole of a convergence unit and another nonmagnetic body section, cutting and working them, and forming the cavity wall of an input or output cavity. CONSTITUTION:After an input section magnetic pole piece 4 and a drift pipe 13 are brazed, they are cut and worked up to the position indicated by a broken line and a groove 14 for brazing and such are removed. A work surface is finished precisely and the sliding surface of a sliding element is formed into an exceedingly flat plane. In addition, subsequently, a part that forms the wall surface of an input cavity, another section of a high frequency circuit section, an input waveguide, and such are joined by brazing and a multi-cavity klystron shown in the drawing is manufactured finally.

Rotary fluid pump

Abstract: The invention is fluid pump which in addition to displacing fluid can be a fluid driven motor and when the fluid is compressible a compressor or expanding fluid driven motor. The pump has an annular cavity formed between its rotor and casing and around the rotor rotational axis. There is a power transfer means such as a shaft which drives the rotor in rotation when the pump is used to displace or also to compress a fluid. When the pump is used also as a motor the fluid being displaced is also the power transfer means and the rotor shaft is used for mechanical power take-off. The rotor surface at the annular cavity, the wave surface, has at least one undulation and each wave surface undulation forms with the other cavity surfaces a cavity undulation. A casing surface at the annular cavity, the face surface, has a plurality of circumferential spaced axial plane slots each with a partition pivotally extending into the annular cavity but not abutting the annular cavity walls. The partitions in the annular cavity form a plurality of circumferential spaced volume varying chambers which cyclically vary in volume during their traverse of the cavity undulation(s) with rotor rotation. With rotor rotation, the partitions are displaced in their slots by a rotor cam means outside the annular cavity with undulations which maintain the continuous pivotal extension of the partitions into the annular cavity towards without abutting its surfaces. Where neighbor cavity undulations join there is a sump region of the annular cavity. Each said sump region extends from the exhaust region of one cavity undulation to the neighboring cavity undulation's intake region and volume varying chambers traversing the sump regions have minimum volumes. Each annular cavity undulation in the pump is comprised of (in the direction of volume varying chamber traverse): a sump region segment at its beginning, then an intake region with intake means, then a fluid transfer region, then an exhaust region with exhaust means, and then a sump region segment at its end. In the annular cavity's fluid transfer and the sump regions the partitions are extended to very close proximity with cavity walls. In the pump's operation each volume varying chamber traversing a cavity undulation conveys fluid from the cavity undulation's intake means at its intake region across its fluid transfer region to its exhaust means at its exhaust region. When the fluid is compressible, and the pump is also an (expanding) fluid motor the fluid in a volume varying chambers in the fluid transfer region works on the rotor. When the pump is also a compressor the rotor works on the fluid in the fluid transfer region compressing it. The power loss in the pump due to the allowed mass flow between neighboring volume varying chambers is sustained in the invention rather then the power loss and wear of the parts that occur if the partitions have wiping abutment with the cavity walls.

A method of building a cavity wall using a building tie, and building ties for use in the method.

Abstract: A method of building a cavity wall including the step of embedding in the leaves of the cavity wall a tie to locate them in position characterised in that a tie is used in which at least the portions which are located in the walls and adjacent to the leaves of the wall are of spiral form and obtained by twisting a flat strip of metal.

Passive solar energy : modifications of existing masonry walls to improve thermal performance

Abstract: Existing brick walls usually have a high U value, one method of improvement is by insulation, but if the wall faces approximately south, it is possible that greater benefits could be obtained by improving the wall's performance as a solar collector. Three solid 225 mm walls were constructed: one glazed, one unglazed, and (since glazing prevents rain penetration) one waterproofed unglazed wall. Two glazed cavity walls were also constructed one glazed with a fan to recover heat from the cavity by forced convection, and one unglazed, with no fan. These walls gave small heat gains. The walls behind the glazing were then insulated on their outer faces, and warm air collected by natural convection. Such a collector was built using a selective surface, a maximum efficiency of about 50% was observed. A theoretical model was developed based on simple steady state theory, this was found to correlate well with experimental data. The theory could be used for any system of low thermal storage, including forced flow collectors. Finally these walls, and others, are compared and their relative merits discussed.