Showing papers on "Cavity wall published in 1988"

Mode suppressors for whispering gallery gyrotron

Abstract: A gyrotron interaction resonator 29 operating in a TEn1 cavity mode has an array of longitudinal slots 32 in the conductive wall 30. The slots 32 are spaced to couple to the unwanted TEn1 modes and to other modes of differing n and not to the desired mode. Wave-absorptive material 34 spaced from the inner cavity wall 28 and coupled to slots 32 absorbs the unwanted modes.

Method and apparatus for injection moulding

Abstract: An injection molded plastic article is produced by introducing a stream of molten plastic material from an injection molding machine cylinder into an article forming mold space. Pressurized gas is supplied into the interior of the molten plastic material to form a gas containing cavity therein. The plastic material is then allowed to solidify and cool sufficiently so that the article can itself sustain the form dictated by the mold surface. The cavity is vented to reduce the pressure within the cavity to ambient pressure prior to opening of the mold. The step of venting the cavity is achieved by providing at least one position which is separate from the plastic inlet and the gas inlet a vent passage in the mold open at its inner end to a part of the interior of the mold at which the gas containing cavity is formed, and a retractable closure for opening and closing the vent passage at its inner end, maintaining the closure in its closed position during the forming of the article whereby the cavity wall is formed over the inner end of the vent passage and the closure therefor, and subsequently retracting the closure to allow the creation of a vent opening in the cavity wall in the area of the inner end of the vent passage through which vent opening gas from the cavity passes into the vent passage. Apparatus for carrying out the above process is also described.

A new cavity configuration for cesium beam primary frequency standards

Abstract: In the design of cesium beam frequency standards, the presence of distributed cavity phase shifts (associated with residual running waves) in the microwave cavity, due to the small losses in the cavity walls, can become a significant source of error. To minimize such errors in future standards, it has been proposed that the long Ramsey excitation structure be terminated with ring-shaped cavities in place of the conventional shorted waveguide. The ring cavity will minimize distributed cavity phase variations at the position of the atomic beam, provides only that the two sides of the ring and the T-junction feeding the ring are symmetric. A model is developed to investigate the validity of this concept in the presence of the small asymmetries that inevitably accompany the fabrication of such a cavity. The model, partially verified by laboratory tests, predicts that normal tolerances will allow the frequency shifts due to distributed cavity phase variations to be held at the 10/sup -15/ level for a beam tube with a Q of 10/sup 8/. >

Insulation displacement members and electrical connectors

Abstract: Insulation displacement terminal member having cantilever spring contact members which are spaced-apart to receive a conductor between them. Each contact member has an outward projection for engagement with the wall of a cavity of a connector housing to prevent undue movement apart of the members when a heavily insulated conductor is forced between them under extremely cold conditions. Ideally, the projections are convex to permit a rolling action upon the cavity wall.

Method and apparatus for stitch-machining deep cavities in metal workpieces

Abstract: Stitch-machining the walls of a cylindrical blind cavity (10) of a workpiece (14), the cavity (13) being deep and narrow with respect to the axis of the cavity, is carried out by: (a) supporting a tubular housing (10) for axial movement throughout substantially the axial extent of the cavity interior and in close-fitting tolerance to the walls of the cavity, the tubular housing (10) having a free end; (b) rotationally driving a spindle (23) in the tubular housing (10) for conjoint axial movement with the tubular housing, the spindle (23) extending beyond the housing (10) end for carrying a radially adjustable cutting tool (24); (c) inserting the tubular housing (10) together with the rotationally driven spindle (23) in the cavity (13) with the cutting tool (24) radially positioned for rough boring of the cavity walls, while guiding and steering the tubular housing (10) and spindle (23) to accurately concentrically position the cutting tool (24) with respect to the cavity axis ; and (d) substantially immediately upon the execution of rough boring, withdrawing the tubular housing (10) together with the rotationally driven spindle (23) from the cavity with the cutting tool (24) repositioned for finish boring of the cavity wall during withdrawal.

Solar heated cavity wall

Abstract: A new or an old, conventional cavity wall has a selective coating 2 applied to its external surface to produce high solar absorptivity but low longwave emmisivity. To this combination a suitable air gap, frame and glazing 1 is provided to protect the outer leaf. Heat produced by the absorption of solar radiation on the selectively coated surface passes by conduction through the outer leaf into the cavity. Air flowing from an inside room to the bottom of the cavity 7 is heated and exits at the top 9. A small fan 8 may be inserted into the air stream to improve the solar wall's performance.

Securing of insulating panels in cavity walls

Abstract: An insulating panel or cavity batt (12) is secured to the inner brick wall (16) of a cavity wall by a device (10) which comprises a shaft (24) having at one end a disc (20) engageable with the panel, and at the other end a locating means for engaging the inside of the outer wall (14). The locating means may be a flat bifurcated member (28) which, during construction of the cavity wall, is embedded in the mortar between layers of brick; or it may be a disc like disc 20 having a pin which penetrates the wall. The shaft (24) may be made in a range of lengths to suit the cavity width; or it may be adjustable and incorporate a ratchet which may be extensible by a pinion gear engageable with a rack formed in the shaft.

Masonry support for cladding forming an outer skin of a cavity wall

Abstract: A masonry support system for supporting an outer skin of masonry of a cavity wall in a multi storey building having a concrete or steel framed inner wall structure comprises a masonry support plate 10, 30 rigidly secured to brackets 11; 31, 32 having upper and lower abutment means 18; 37, 38 to receive a washer plate 12, 34. The washer plate has an inclined closed ended opening (Fig 4, 19), 35 which intersects an upright slot (16, Fig 1) 36 in a web (40, Fig 8), 31 of the bracket. A bolt stud projects through at the point of intersection from the inner wall structure and is tightened to secure the masonry support in position. Up and down adjustment is achieved by sliding the washer plate 12, 34 laterally between the abutments. Two embodiments are described, the first of which uses a vertical channel section bracket with the web 14 linked to side walls (15, Fig 3) forming bridging flanges across the cavity, the slide walls having slots 18 defining the upper and lower abutments for the washer plate. The masonry support plate forms parts of a cold formed angle section 10. Gussets 22 stiffen the angle section 10. The second embodiment includes a single cavity bridging flange 32 affording the lower abutment 37 and a perpendicular web 31 affording the slot 36 and upper abutment 38. The bridging flange 32 is welded to a flat plate 30 forming the masonry support plate.

Programmable mechanical delay line

Abstract: A programmable mechanical delay line is disclosed comprising one or more lengths of axially movable co-axial cable. The inner and outer conductors of the cable length are respectively accepted within cavities having electrically conductive inner walls. The conductors are electrically coupled to the cavity walls by respective toroidal springs which circumvent the conductors and which contact the cavity walls at their outer diameter. The minimal surface contact by the toroidal springs reduces wear and friction. The reduction in friction substantially eliminates overshoot which previously resulted from attempts to rapidly reposition the coaxial cables. Consequently, the disclosed device provided very rapid, repeatable, and accurate adjustment as different amounts of signal delay are desired.

Method & means for fixing building components together

Abstract: Method and means for fixing together building components, such as two skins of a cavity wall (10, 11). The components are "tied" together using a rod (13), inserted into holes (17, 18) drilled through the two components, on which are positioned a sleeve (20) such that it spans the cavity between the building components and three washers (22, 24, 26). The sleeve and washers are movable relative to each other and have ports (21, 23, 25, 27) which may be axially aligned to allow passage of a feeder pipe (28) for injecting binder (15) into the holes around the rod, or may be moved into disalignment to effect seals to prevent the binder from escaping from the holes.

High Frequency Seismic Source Characteristics of Cavity Decoupled Underground Nuclear Explosions

Abstract: : The research investigated the high frequency characteristics of the seismic sources corresponding to cavity decoupled nuclear explosions and to assess the implications of these investigations with regard to the detection and discrimination of small decoupled explosions. This study has been carried out using a combination of deterministic simulations and analyses of empirical data recorded from selected cavity decoupled explosions. With regard to the deterministic simulations, a series of nonlinear finite difference calculations have been performed to simulate cavity decoupled explosions in unsaturated tuff and salt emplacement media. These simulations have confirmed the fact that the simple step pressure approximation is not valid at high frequencies and that the initial pressure spike on the cavity wall can induce significant nonlinear response. Preliminary analyses of high frequency seismic data recorded from the STERLING decoupled explosion in salt and the MILL YARD decoupled explosion in unsaturated tuff have provided evidence that the high frequency source components associated with the complex cavity pressure loadings do effectively couple into the seismic regime, in agreement with the predictions of the nonlinear finite difference simulations.

Form molding machine

Abstract: PURPOSE:To improve the productivity and to uniform the quality, by injecting an expandable cooling medium to the surface of a molding die and cooling a molding uniformly. CONSTITUTION:A pre-expanded bead charged into a cavity 6 is heated and expanded, and thereafter a high-pressure expandable cooling medium 15 is injected to a cavity wall 4 and a core wall 5 through a spray nozzle 12. Because of the violent drop in pressure and skyrocket in temp., the injected droplet evaporates and turns into fine spray and adheres to the walls 4 and 5 uniformly. In addition, the liquid membrane of the cooling medium adhered to the walls 4 and 5 is divided finely by the remaining gas occurring there to promote the vaporization. By these functions, the walls 4 and 5 are deprived of the vaporization heat rapidly and an expanded molding 7 is cooled effectively and uniformly. Consequently, the cooling time, the cooling dissipation time and the total cycling time can be saved, and besides, the moisture content of the molding is reduced and the quality can be stabilized as well.

Damp proof strips or cavity trays with flashing attachment

Abstract: A cavity tray for building into the outer skin of a cavity wall is formed as a single integral injection moulding and comprises a base portion 1, arear wall 2, an end wall 4 and a gully 5 in the base portion 1 adjacent the rear wall 2. To facilitate the fastening of a strip of lead flashing to the front edge of the base portion 1. the base portion 1 has an upwardly stepped portion 7 and a downwardly projecting flange 9 which is connected to it by an integrally formed hinge 10 of the plastics material. The flange 9 is provided with spaced projections 11 which pass through perforations in the flashing and into apertures 8 in the stepped portion 7. To lock the flashing strip in position, the tips of the projections 11 may then be heated to melt them and form buttons on their ends so that they cannot pass back through the apertures 8.

Analysis of the EM scattering from arbitrary open-ended waveguide cavities using axial Gaussian Beam tracking

Abstract: The electromagnetic (EM) scattering from a planar termination located inside relatively arbitrarily shaped open-ended waveguide cavities with smoothly curved interior walls is analyzed using a Gaussian Beam (GB) expansion of the incident plane wave fields in the open end. The cavities under consideration may contain perfectly-conducting interior walls with or without a thin layer of material coating, or the walls may be characterized by an impedance boundary condition. In the present approach, the GB's are tracked only to the termination of the waveguide cavity via beam reflections from interior waveguide cavity walls. The Gaussian beams are tracked approximately only along their beam axes; this approximation which remains valid for relatively well focussed beams assumes that an incident GB gives rise to a reflected GB with parameters related to the incident beam and the radius of curvature of the wall. It is found that this approximation breaks down for GB's which come close to grazing a convex surface and when the width of the incident beam is comparable to the radius of curvature of the surface. The expansion of the fields at the open end depend on the incidence angle only through the expansion coefficients, so the GB's need to be tracked through the waveguide cavity only once for a wide range of incidence angles. At the termination, the sum of all the GB's are integrated using a result developed from a generalized reciprocity principle, to give the fields scattered from the interior of the cavity. The rim edge at the open end of the cavity is assumed to be sharp and the external scattering from the rim is added separately using Geometrical Theory of Diffraction. The results based on the present approach are compared with solutions based on the hybrid asymptotic modal method. The agreement is found to be very good for cavities made up of planar surfaces, and also for cavities with curved surfaces which are not too long with respect to their width.

Connection for cellular-concrete construction parts

Abstract: The connection element consists of a thin metal strap having anchor elements on the bearing faces. The anchor elements are claws projecting at right angles, which are butt-welded to the plate or punched from the strap and have a tip at the end face. They are set by driving in with planarity and are universally usable, e.g.: - as wall anchors for fastening cellular-concrete wall construction parts to steel or reinforced concrete columns; - as dowelling elements for roof and ceiling construction parts; - as means for the partial fixing of roof and ceiling construction parts to the centre support to reduce deflection; - as anchoring means for ring beams and - as cavity-wall anchors in two-leaf cavity wall construction with cellular-concrete wall blocks or wall construction parts. The connection element according to the invention opens up new avenues in cellular-concrete construction using the dry construction method, which contributes considerably to more rapid construction progress without waiting times, to a rationalisation and hence to improved efficiency.

Cavity wall ties for brick (outer) & timber inner skins

Abstract: A tie for securing an outer skin to a timber framed inner skin comprising a wood-penetrating and gripping means 20, a cavity-spanning portion 12 and a section 14 which can be used to fix the tie to the outer skin A method of securing a brick or stone outer wall skin 22 to a timber frame 26 in which a hole 34 is drilled through the outer wall and a tie having a wood thread at one end is inserted through the hole from the outside and screwed into the wooden frame, a head end of said tie being thereafter secured to the outer skin

Cavity wall injecting machine

Abstract: There is disclosed a control arrangement for a cavity wall insulation injecting machine having a shredding arrangement 11 delivering into a rotary air lock 12 supplied with air through a line from a blower 14, the control arrangement comprising valve means 22, 23 in said line adapted to switch air between the air lock and exhaust 29.

Dielectric-loaded circular ridge waveguide applicator for hyperthermia

Abstract: An applicator for intracavitary hyperthermia treatment of cancer has been designed and tested. The applicator is a section of a dielectric-loaded circular ridge waveguide closed at both ends to form a transmission cavity. An aperture in the cavity wall can produce a directed heating of a tumor growing in the wall of a body cavity such as the vagina.

Cavity resonator op microwave tube

Abstract: PURPOSE:To facilitate regulation of a resonance frequency by disposing an axis of a resonance cavity be eccentric to that of drift tubes and unitedly forming a projecting part which extends along a partial axis on an inner wall of the cavity. CONSTITUTION:A resonance cavity 12 comprising a nearly doughnut-shaped space is formed of a cavity wall 11. Drift tubes 13 and 144 serving as channels for electron beams are disposed face each other projectingly in the cavity 12 and a gap G is formed by the drift tubes 13 and 14. An axis 15 of the cavity 12 is disposed eccentric to an axis 16 of the drift tubes 13 and 14. Besides, a projecting part 17 extending along a partial axis is unitedly formed on an inner surface of the cavity wall 11 of the cavity 12. A resonance frequency can be easily regulated by rotating the cavity wall 11 around the axis 15 on an assembling time so as to change the position of the projecting pert 17 and by changing a spacial inductance of the cavity 12. After the regulation is finished, the cavity wall 11 is airtightly jointed with the drift tubes 13 and 14.

A cill for use with a cavity wall

Abstract: A cill arrangement 10 for mounting a door or window frame 21 on a support surface 11 of an outer skin 12 of a cavity wall comprises an upright plate 17 for insertion with the cavity, a first support 15 extending laterally from said plate on one side and a second support 19 extending laterally from the other side of the plate at a lower level than the first support The first support 15 is vertically spaced from the upper edge of the upright plate so as to form a cill upstand 18, and the lower edge of the frame is placed on top of support 15 and adjacent the cill upstand 18 Capillary channels 28 may be provided on the upstand 18 and second support 19 to further impede the ingress of water

Structural ties for walls

Abstract: A cavity wall has an outer leaf 4 of conventional brick and mortar construction and an inner leaf built up from a number of large panels 1 of aerated concrete. Panels of insulation are included in the cavity. The cavity is maintained and the insulation positioned by a number of wall ties 3 embedded in mortar in the brickwork 4 and driven through the insulation 2 and directly into the aerated concrete 1 without a pilot hole having been bored first in the aerated concrete.

Explosion-proof device

Abstract: The utility model relates to an explosion-proof device which is applied to a food pressure cooker, which is also provided with an air outlet nozzle, an air exhaust pipe, a small through hole on one side wall, and a pressure limiting valve which is sheathed on the top of the air exhaust pipe which are arranged on the cooker lid as the explosion-proof device of the ordinary food pressure cooker, and the air outlet nozzle which extends into the inner cavity end portion of the food pressure cooker lid is additionally provided with a fixedly connected explosion-proof filter sheet. The explosion-proof filter sheet is distributed with a series of through holes, the dimensions of which are smaller than the dimensions of the side holes of the air outlet nozzle, and the periphery of through holes is tightly contacted with the inner cavity wall of the food pressure cooker lid. Thus, all kinds of easily blocked objects of the high pressure gas zone in the food pressure cooker can be blocked on the lower side of the explosion-proof filter sheet; since the dimensions of the object grains which pass through the filter sheet are smaller than the dimensions of the through holes of the air outlet nozzle, and accordingly, the object grains of the filter sheet can be easily discharged out of the food pressure cooker.

Monitoring, computer simulation and improvement of the performance of a fan assisted solar wall

Abstract: The thermal performance of a solar wall in a low energy school at Poulton Lancelyn, Wirral has been evaluated from measurements made during 1985-86. A computer model, developed to compare the efficiency of heat production by several wall types, predicts that a single glazed 200 mm thick brick wall produces little heat during winter. Conversely, a single glazed selectively coated, 100 mm thick wall works well, giving greater efficiencies throughout the year. Models of these two types of wall were built. Measured efficiencies confirm the computer predictions. Thus a standard well insulated cavity wall may be modified with glazing and selective coating to act as an efficient solar storage wall in Northern England.

An arrangement in a microwave oven

Abstract: In certain types of microwave ovens, e.g. ovens of the single-wall type, the manufacturing of the oven cavity (10) involves the forming of at least one groove-­shaped recess (16) in at least one of the cavity walls (14). In order to substantially eliminate the disturbing effect of this recess (16) on the microwave field pattern in the oven cavity (10), a reflecting element in the shape of an elongated strip (18) of conductive material is provided in a position at the entrance opening of the recess (16), as seen from the oven cavity (10). The conductive strip (18) is preferably covered by dielectric material, e.g. in the shape of a dielectric plate (20) that also serves as support for the strip (18), and this strip (18) is so dimensioned and disposed at the opening of the recess (16) that it substantially reflects all incident microwave radiation coming from the oven cavity (10) at the opera­tional frequency of the microwave oven.