Abstract: A heat-transfer tube with a grooved inner surface adapted to phase-transition for fluid flowing inside the tube disposed in a heat exchanger is disclosed. This tube can achieve the reduction in the weight per unit length, improvements in workability and characteristics of the tube by limiting the cross-sectional area of respective grooved section and the shape of the ridge defining the grooved section.

Abstract: A heat exchanger suitable for use with a combustion heater, comprises a one-piece extruded tubular heat exchanger element having a tubular body and a number of interior and exterior fins projecting integrally radially from the tubular body.

Abstract: A heat exchanger capable of use as a counter-flow heat exchanger comprises a series of conduits for a first fluid, the conduits being arranged in panels that are spaced apart. The intervening spaces are traversed by a second fluid, and surface-extending elements are located in such spaces, each surface-extending element comprising a sheet from which portions have been pressed out to define a number of knuckles that are located in heat-transmitting contact with a conduit panel on one side of the space. At least some of the knuckles may be secured to the conduit panel.

Abstract: Surgical apparatus for use in contouring medical implants comprises a transparent enclosure adapted to be located on a metallic work surface in an operating theater, the enclosure being sized to enable manipulation of an implant therein by a surgeon for contouring, a stand connected to the enclosure for adjustably positioning and fixing a surgical drill in a preselected orientation with respect to the work surface such that the drill bit projects throughout an opening into the interior of the enclosure, the stand carrying a magnetic mechanism so as to enable the stand to be immobilized with respect to the work surface, and a movable cutting block having a disposable cutting surface thereon. The stand is connected to the enclosure by a metal tongue, slidably carried by the stand, which is received within a slot on the underside of the enclosure, and the cutting block is formed with a magnetic mechanism so as to enable immobilization of the cutting block with respect to the tongue.

Abstract: A rotary gear pump having inner and outer gear rotors of the type having respective inner and outer surfaces whose cross sections are determined utilizing the trochoidal curve, the inner gear rotor having trochoidal dimensions which either eliminate or diminish to a negligible amount the edge portion of the teeth which cause excessive wear, noise or inefficiency. In one embodiment of the invention, the dimensions of the inner gear rotor are such that C/K.sub.0 .ltoreq.1 or f.sub.c /K.sub.1 .ltoreq.1.1, where C is the rotary path diameter, K.sub.0 =(A/B+1).times..vertline.B-2e.vertline., K.sub.1 =(n+1).times..vertline.1-2f.sub.e .vertline., A is the diameter of the base circle, B is the diameter of the rolling circle, e is the eccentricity, n=A/B, f.sub.e =e/B, and f.sub.c =C/B. In accordance with a second embodiment of the invention, a comparable result can be obtained provided that the number of teeth on the inner gear rotor is equal to an integer closest to the ratio d.sub.4 /2e, wherein d.sub.

Abstract: A method and apparatus are disclosed for simultaneously regulating the temperature of interior air, and ventilating the interior air with air from outside by means of passing said interior air through an interior heat exchanger, simultaneously passing outside air through an outside heat exchanger, extracting a portion of the inside air, and directing it to the outside air for venting outside, simultaneously extracting a portion of the outside air and venting it to the inside air, continuously passing a heat exchange medium into one of the heat exchangers, and transferring the heat exchange medium from one heat exchanger to the other heat exchanger, via an expansion device to procure transfer of heat from one heat exchanger to the other, and passing the heat exchange medium through flow controls, responsive to temperature of the inside air, to selectively direct flow of medium either to one of the heat exchangers or to the other. Also disclosed is a method of regulating temperature by means of the system.

Abstract: For parallel heat exchangers, one using a more preferred heat exchange medium as a heat exchange source and another using a less preferred heat exchange medium, maximum use of the more preferred heat exchange medium is used prior to use of the less preferred heat exchange medium in achieving a desired total heat exchange through the parallel heat exchange system. In employing such a heat exchange system in a cracking process it is combined with individual control of flows of feed fluid and diluent fluid to a plurality of individual cracking tubes in a cracking furnace to maintain a desired mass flow of feed fluid and ratio of mass diluent fluid to steam fluid to each such cracking tube.

Abstract: A holder of a valve prosthesis implantable in a patient's circulatory system, including arms which have handles at one of their ends, and three or more working jaws provided at the end thereof for a valve prosthesis to secure thereon. The ends of all the working jaws form a circle when brought apart.

Abstract: A plate type heat exchanger consists of a plurality of heat transmission plates which are piled up and secured to each other. Side wall members are interposed between the adjacent heat transmission plates, so that multiple stages of spaces are formed in the heat exchanger. Additionally, separator wall members are interposed between the adjacent heat transmission plates in such a manner that two fluid paths are defined in alternate stages of the spaces. The side wall members and the separator members are formed of rod material, thereby rendering the heat exchanger light in weight while lowering the production cost of the heat exchanger.

Abstract: A vehicle air conditioner is provided with a "lost motion" mechanism for drivingly connecting first and second shafts with one common actuator such that an air-mix door and a water cock are driven by the one common actuator.

Abstract: An air conditioning unit comprises a cooling unit and a heating unit and is provided with dehumidifying mode for drying the through-flowing air. The operation of the dehumidifier results in activation of the cooling unit compressor, which reduces the air temperature inside the vehicle. Switching circuits are provided for compensating for this reduction in temperature. The compensation in the switching circuits is dependent on the outside temperature and is ineffective if the cooling unit is running at "full cooling" when the dehumidifier is switched on, or if the outside temperature is below 0 degrees centigrade.

Abstract: A heat exchanger of the type having a tube assembly made up of a number of tubes through which a first medium flows and around and between which a second medium flows to accept heat from, or transfer heat to, the first medium. One of the media is constrained by baffles to follow a tortuous path through the heat exchanger. According to the invention, the baffles are completely separate from the tubes, so permitting them to be replaced or adjusted without the necessity of disassembling the tube assembly. The baffles can be carried releasably on rods which allow their spacing to be adjusted at will, with the result that heat exchangers according to the invention are more versatile than conventional heat exchangers where the baffles are fixed to the tubes.

Abstract: A waste heat recovery apparatus is disclosed which recovers the waste heat of high temperature exhaust gas discharged from a furnace. The apparatus includes a radiation body made of ceramic material, which is formed with a heat radiation surface arranged adjacent to an exhaust gas outlet of the furnace, and directed toward the inside of the furnace. The radiation body has a plurality of regular channels allowing passage of the exhaust gas therethrough. Exhaust gas passes through the channels and heats the radiation body, and a substantial amount of the holding heat of the exhaust gas is radiated from the radiation surface toward the inside of the furnace, allowing an efficient waste heat recovery.

Abstract: A process for the setting of a constant temperature for a fluid, and furtmore, to a thermostat for implementing the process. The constant temperature is set by the heating up of the fluid during its flow through a heat source. The fluid, prior to the setting of the constant temperature, is initially cooled down to a lower temperature, such that the temperature difference which is reached between the constant temperature and a lower temperature, is higher than the temperature-overshooting range of the cooling regulating circuit. These measures simplify the setting of the constant temperature inasmuch as only the heat source need be equipped with a high-performance regulator. Through the cooling section which is connected ahead of the heating element, there is maintained a minimum temperature differential.

Abstract: In an internal combustion engine having a pair of intake valves, the valve driving system for timing the intake valves is provided with a valve timing changing mechanism for changing the timing of at least one of the intake valves. The valve timing changing mechanism retards or advances the timing of said one intake valve to change the total intake valve opening time, i.e., the time that at least one of the intake valves is open, according to the operating condition of the engine.

Abstract: A cross-counter-stream module for material and/or heat exchange done with a hollow filament bundle cast into a housing at its ends and a mechanism for conducting the material flow to the outside of the hollow filaments. The hollow filaments are cast at their ends as a stack into a housing, the stack being composed of one or more layers which consist of strata of hollow filaments fixed in a plane through cross-pieces transverse to their lumen directions, the cross-pieces being arranged tightly superimposed at all locations inside one layer, disposed at predetermined constant intervals, with the intermediate spaces between the hollow filaments filled by the cross-pieces at the places of crossing, and with the cross-pieces composed of a polymer with a melting point from 80.degree. to 190.degree. C. and a residual adhesion at room temperature. Preferably, the polymer is a polyamide, a polyethylene, a copolymer of polyethylene and vinyl acetate, or a copolyether-ester.

Abstract: A heat-conducting cooling module for cooling a semiconductor substrate in an integrated circuit package assembly in which a semiconductor substrate is mounted on a base board by small solder pellets, and which contains a single substrate or laminated substrates. A heat-conducting relay member is provided between the semiconductor substrate and a housing so as to be pressed onto the semiconductor substrate. At least either one of the housing or the heat-conducting relay member is made of a sintered product which includes silicon carbide as a chief component.

Abstract: The invention is, on the one hand, a heat exchanger comprising at least one tube (1) and at least one ribbing made of a heat conducting material folded to a concertina-like shape, where the ribbing has ribs (2), each of them being substantially perpendicular to the axis (10) of the tube (1) and comprising wings (4A, 4B) and a rib base (3) between them, and where the ribs (2) are attached to the tube (1) at their rib base (3). At least one of said wings (4A, 4B) of each ribs (2) comprises patterns interrupting the continuity of the wing material, and/or bent surfaces making an acute angle (.alpha.) to a plane perpendicular to the axis (10) of the tube (1). The patterns may be cutouts (7A, 7B), holes (8), outpressed parts (9) or embossings (17A, 17B).

Abstract: A heat exchange apparatus including a generally cylindrical hollow housing having an upper end and a lower end, and a heating device disposed in the lower portion of the housing. A heating coil assembly is disposed within the housing over the heating device, and includes a radially inner coil bank and a radially outer coil bank adjacent the inner wall of the housing. An intermediate coil bank is connected between the inner and outer coil bank and includes a plurality of helical convolutions of increasing diameter as they successively occur in an axial direction from the lower end of the housing toward the upper end thereof. A baffle frame assembly interconnects and spacially orients the inner and intermediate coil banks, and radially outwardly deflects heated gases from the heating device.

Abstract: A valve train of an overhead camshaft engine is provided with a mechanism for taking up slack in the valve train. The slack take up mechanism is constituted by a tappet, an oil pressure chamber, a coil spring, etc. and constructed such that leakage of the oil pressure chamber takes place for take up adjustment during each cycle of valve operation.