Abstract: A retractable leash having a tension strap connected to a safety line that can be releasably fastened to a tethered article. The retractable leash allows freedom of use of the tethered article without the retractable leash impinging any spring force on the tethered article. A retractable leash that employ a series of metal rings, a plastic spacer and a flat sided ball that can rotate in any direction to guide and to prevent tangling of the tension strap and preclude friction from the plastic collar edges. A retractable leash that uses means of a furrow in the spring cup for locking the inner loop of the tension strap from rotating. A retractable leash having an arbor with a flat side for mounting a spring retaining clip thereto and a central bore that keeps debris out of the spring cup in sandy conditions.

Abstract: A shank mount assembly for a water heater that includes an annular nipple having an opening, the nipple configured to removably attach to an opening in a water heater tank. The shank mount assembly further includes an annular shank mount having an opening, the shank mount configured to removably attach to the nipple, wherein the shank mount is further configured to attach to a gas valve assembly.

Abstract: A remedial pollution control system for treating volatile organic compounds that may include a vapor concentrator connected to a line that is laden with volatile organic compounds, the concentrator has an organic condensate output line and a vapor output line; a mixing chamber adapted to receive air provided from an air supply line, combustible fuel from an alternate fuel supply line, and a vapor stream from the vapor output line to produce a mixed fuel supplied to an internal combustion engine, a control mixing system with a controller for producing a proper air to fuel ratio in the mixed fuel supply, and power generated to operate other devices used to more efficiently abate volatile organic compounds and reduce greenhouse gas emissions.

Abstract: An intake-side space around intake ports and an exhaust-side lower space around exhaust ports are provided in a main cooling jacket portion. These spaces are connected to each other. In a sub cooling jacket portion, an exhaust-side upper space is provided at a level above the exhaust-side lower space. The main cooling jacket portion and the sub cooling jacket portion are connected to each other via a cylindrical-hole connecting passage extending vertically and separate from each other vertically via a wall portion in another area than the connecting passage. Accordingly, a cooling device of an engine which can restrain the exhaust gas from being cooled too much improperly is provided.

Abstract: A variable compression ratio (VCR) apparatus, may include a piston, a connecting rod having one end coupled to the piston through a piston pin so as to transmit a motion of the piston to a crank shaft, a pair of first and second eccentric links having one ends eccentrically connected to the one end of the connecting rod through the piston pin, dual swing links having one ends connected to the other ends of the first and second eccentric links, respectively, so as to pivot the eccentric links with respect to the piston pin, and connecting assembly connecting the one ends of the first and second eccentric links each other.

Abstract: A system for a vehicle includes a mode control module and a valve control module. The mode control module selectively sets an ignition mode for an engine to one of a spark ignition (SI) mode and a homogenous charge compression ignition (HCCI) mode. In response to the ignition mode transitioning from the SI mode to the HCCI mode during a first engine cycle, the valve control module operates an exhaust valve in a high lift mode during a second engine cycle, operates an intake valve in a low lift mode during the second engine cycle, and operates the exhaust and intake valves in the low lift mode during a third engine cycle. The first engine cycle is before the second engine cycle, and the second engine cycle is before the third engine cycle.

Abstract: A lost motion engine valve actuation system and method of actuating an engine valve are disclosed. The system may comprise a valve train element, a pivoting lever, a control piston, and a hydraulic circuit. The pivoting lever may include a first end for contacting the control piston, a second end for transmitting motion to a valve stem and a means for contacting a valve train element. The amount of lost motion provided by the system may be selected by varying the position of the control piston relative to the pivoting lever. Variation of the control piston position may be carried out by placing the control piston in hydraulic communication with a control trigger valve and one or more accumulators. Actuation of the trigger valve releases hydraulic fluid allowing for adjustment of the control piston position. Means for limiting valve seating velocity, filling the hydraulic circuit upon engine start up, and mechanically locking the control piston/lever for a fixed level of valve actuation are also disclosed.

Abstract: A cam can rotate on a camshaft of an internal combustion engine. A rocker arm that actuates a valve of the internal combustion engine can include a rocker pivot connection point located on a distal side of a valve component from a proximate end of the rocker arm that is deflected by action of the cam. The rocker arm can include a contact point located between the rocker pivot point and the proximate end. The contact point can act on the valve component to actuate the valve. The rocker pivot connection point can be translated such that it is closer to or further from the cam. This translation can be used to vary valve lift and/or valve timing. The cam can have a three-dimensional profile to provide different actuation distance of the rocker arm. Systems, methods, and articles of manufacture consistent with one or more of these features are described.

Abstract: Devices and related methods are disclosed that generally involve variable actuation of engine valves. In one embodiment, a valve train for a split-cycle internal combustion engine or an air hybrid split-cycle engine is provided that includes a cam phaser, a dwell cam, an adjustable mechanical element for performing a variable valve actuation function, and/or a valve seating control device. The devices and methods disclosed herein also have application in conventional internal combustion engines and can actuate inwardly-opening and/or outwardly-opening valves.

Abstract: An engine assembly includes an engine structure, a camshaft supported on the engine structure, a first cam phaser coupled to a first axial end of the camshaft, and a locating pin. The camshaft includes a first shaft, a second shaft, a first cam lobe and a second cam lobe. The first shaft defines a first opening. The second shaft is supported within the first shaft and defines a second opening. The first cam lobe is located on and fixed for rotation with the first shaft. The second cam lobe may be located on the first shaft and fixed for rotation with the second shaft. During assembly, the first cam phaser is located on the camshaft and the locating pin may be inserted through the first and second openings to rotationally fix the first and second shafts. The first cam phaser is then secured to the camshaft.

Abstract: In a valve timing control apparatus for an internal combustion engine, a torsion spring whose one end section is fixed into a front side of a housing and whose other end section is fixedly retained into a communication hole to bias a vane member to rotate in one direction, the communication hole being formed in an inner axial direction of the vane member to introduce a working oil within the back pressure into the engine.

Abstract: In a variably operated valve apparatus of an internal combustion engine and a start control apparatus of the same engine, the internal combustion engine being equipped with a crank position control mechanism by means of which a stop position of a piston is controllable at a time of an engine stop and the variably operated valve apparatus being capable of variably controlling at least a closure timing of an intake valve, the closure timing of the intake valve is placed at a first position which is more advance angle side than the stop position of the piston of one of engine cylinders in a compression stroke and which is stop controlled by means of the crank position control mechanism and one of the remaining cylinders which is in a suction stroke has its the intake valve open, at the time of the engine stop.

Abstract: A camshaft adjustment assembly (1), wherein a control valve (4) is provided for controlling the flow of the pressure fluid in the hydraulic chamber, wherein the control valve (4) is supplied with pressure fluid from the region of a camshaft bearing (5) by a fluid channel (6, 7, 8, 9). In order to enable an improved fluid line with little component weakening, the fluid channel (6, 7, 8, 9) is formed as an annular chamber (6), which is formed between the axial end (10) of the camshaft (2) at least sections of which have a tubular design, a flange-like section (11) of a housing element (12) that is connected rotationally fixed to the camshaft (2) and in which the control valve (4) is mounted, a radially inner delimiting surface (13) of the housing element (12), and a section (14) of the wall of the camshaft bearing (5).

Abstract: A variable valve timing apparatus includes a stopper piston which has an equalizing passage in an axial direction. Even if the engaging hole is filled with the oil, the equalizing passage enables the oil flows from an engaging hole to a holding hole when the stopper piston enters into the engaging hole. It is possible to form a vane as narrow as possible, and to enlarge a variable angular range. In addition, the stopper piston has both end faces which are substantially identical in surface area. Even if pulsation arises in oil pressure, pressures acting on both end faces of the stopper piston can be substantially cancelled and position of the stopper piston can be stabilized.

Abstract: A rotor (4) for a camshaft adjuster (14) is provided. The rotor (4) has a rotor core (6) that can be pushed onto a camshaft (2) and rotationally symmetric vanes (8) that extend radially away from the rotor core (6). Here, the rotor core (6) has an axial projection (10) projecting over the vanes (8). A profile (12) extends radially away from the axial projection (10).

Abstract: A stator (20) for a camshaft adjuster (4). The stator (20) has a ring-shaped outer part (50) for the concentric holding of a rotor (22) with vanes (34) that project in the axial direction and are arranged on the periphery around the rotor (22) and a segment (52) that projects inward in the radial direction from the ring-shaped outer part (50) for engaging between two vanes (34) of the rotor (22), in order to form, together with the two vanes (22), pressure chambers (44) of the camshaft adjuster (4). Here, the segment (52) has a cavity (70) for holding a hydraulic fluid from the pressure chambers (44).

Abstract: A variable valve timing control apparatus includes a driving side rotating member, a driven side rotating member, a fluid pressure chamber, an advanced angle chamber, a retarded angle chamber, an intermediate lock mechanism including a locking member and a locking hole engaged with the locking member when the locking member comes to protrude, the intermediate lock mechanism being configured to switch between a locked state and an unlocked state, a relative rotational phase of the driven side rotating member relative to the driving side rotating member being restrained at an intermediate phase in the locked state, a valve allowing a fluid to be discharged when electricity is supplied thereto and allowing the fluid to be supplied when supply of electricity is interrupted, and a control portion, wherein the supply of the electricity to the valve is interrupted after a pressure of the fluid starts to decrease.

Abstract: The mass production of the MultiAir/UniAir of Fiat/INA proves that the hydraulic control can reliably actuate the valves of the modern internal combustion engines, making them greener. Removing the valve springs from the valves and controlling by the cam not only the valve opening but also the valve restoring, the hydraulic system has easier work to do, the rev limit increases, the height and the cost of the engine decrease and the engine can operate according all the MultiAir strategies. Optionally, the control by high speed solenoid valves can be replaced by easier and cheaper control wherein the rotation of the oil piston is what varies the valve lift and the valve duration. If necessary, slow, cheap, low power servomotors can micro-align the angular displacement of different oil pistons to balance the load between the cylinders.

Abstract: An assembly for a valve train of an internal combustion engine, which has a hydraulic support element and a cam follower resting on one end via a bearing surface located on the bottom side thereof on a complimentary end side of a pressure piston of the support element. The piston extends across the outer shell in a bore of a crucible-shaped housing of the support element. The housing has an opening for hydraulic fluid, which is conductible via a channel between the housing and piston through a passage in the pressure piston to a storage chamber. In a section of a direct contact region between the bearing surface of the cam follower and end side of the piston, an anti-turn mechanism for the piston in relation to the cam follower is implemented. The piston is installed in a defined manner and is torsionally oriented in relation to the cam follower.

Abstract: An igniter (20) emitting an electrical field including a plurality of streamers forming a corona includes a corona enhancing tip (52) at an electrode firing end (28). The corona enhancing tip (52) includes an emitting member (58) such as a wire, layer, or sintered mass, formed of a precious metal and disposed on a base member (54). The base member (54) is formed of a nickel alloy. The emitting member (58) has a lower electrical erosion rate and chemical corrosion rate than the base member (54). The emitting member (58) presents the smallest spherical radius of the corona enhancing tip (52) at the outermost radial point (56) to concentrate the electrical field emissions and provide a consistently strong electrical field strength over time.

Abstract: A starter includes a shift lever that is engaged between a washer and a space collar and moves an output shaft in an axial direction, and a locking portion that is disposed between a snap ring attached to the output shaft and the shift lever to be movable on the output shaft and locks at least a part of an outer circumference portion of the snap ring when the shift lever is engaged between the washer and the space collar. An axial length of the locking portion is shorter than an axial movable length of the locking portion when the snap ring is attached to or removed from the output shaft and longer than the axial movable length of the locking portion when the shift lever is engaged between the washer and the space collar.

Abstract: A starter motor arrangement comprises a battery, a first starter motor including a first pinion and a second starter motor including a second pinion. The first starter motor is connected in series to the battery and the second starter motor is connected in series to the first starter motor. Accordingly, the battery, the first starter motor, and the second starter motor are all connected in series. The first pinion gear and the second pinion gear are configured to engage an engine ring gear when electrical current flows through the first starter motor and the second starter motor.

Abstract: An engine system and method for improving engine starting are disclosed. In one example, two engine cylinder port throttles are adjusted differently during engine starting. The system and method may improve engine torque control during an engine start.

Abstract: A sound transmission system of a motor vehicle, having an intake sound transmission device which can be coupled via a first tubular connecting element to an air intake manifold which leads to an internal combustion engine and via a second tubular connecting element to a vehicle interior, the first tubular connecting element being assigned a first switchable shut-off device, having a resonator device which interacts with the intake sound transmission device and can be coupled via a third tubular connecting element to the air intake manifold which leads to an internal combustion engine, the third tubular connecting element being assigned a second switchable shut-off device.

Abstract: Multi-section sleeve valves for internal combustion engines for improved aspiration. An open connecting rod section is separated from an internal, tubular passageway by a closed wall. A port section proximate the wall defines valve ports. A power stroke midsection borders the port section. An oiling section borders the midsection, and an open section adjacent the oiling section is in fluid flow communication with the tubular passageway. The lower-diameter midsection forms a relief annulus between the valve and the tunnel or sleeve in which the valve is disposed. Fluid flow occurs through the valve interior and through ports dynamically positioned above the compression cylinder, proximate aligned sleeve and head ports. Sleeve ports are separated by bridges that maintain valve rings in compression during reciprocation to prevent damage. High pressure gas is confined between axially spaced apart, stepped sealing rings that prevent gases from flowing axially about the valve exterior.

Abstract: A transmission or engine pan is provided for holding the lubricating fluid. A plug is removably installed in a drain hole in the bottom of the pan to allow the fluid to be drained. The floor of the pan slopes to the drain hole. The bottom wall of the pan may have a tapered thickness from the side walls to the drain hole, or may have a constant thickness. The bottom exterior of the pan is flat, or alternatively may include ribs which define a horizontal surface for receiving a jack.

Abstract: An internal combustion engine (1), includes a cylinder head (2) and a cylinder block (3), with a crankcase (10) being fixed to the cylinder block (3), and with the crankcase (10) including at least one oil pump. In order to reduce the production effort the oil pump is arranged in the crankcase (10), with the oil pump (40) being connected with a flange (43), and with the flange (43) being fixed to a mounting wall (42) of the crankcase (10).

Abstract: A rotary engine according to the present invention comprises a main housing assembly and a rotor assembly rotatably supported within the housing. The rotor assembly has two rotors, an intake/compression rotor rotatably disposed within the intake/compression housing, and a power/exhaust rotor rotatably disposed within the power/exhaust housing. The rotors have N number of apexes and sides, wherein N is an integer greater than 2. A rotating chamber is formed between each side of the each rotor and the inner wall of the respective housing. The stages of the thermodynamic cycle of the engine occur within these chambers. For example, if the rotors have three sides, the rotors will have a triangular-like shape with three apexes. The apexes form the outermost radial part of the rotors which engage the inner wall of the respective housing bore. Each of these chambers is split into two divided chambers by a reciprocating vane, thereby forming 2 times N divided chambers in each of the respective housing bores.

Abstract: Passageways are provided within the combustion chamber of a fuel injected internal combustion engine to convey injected fuel to desired positions within the combustion chamber. The fuel-conveying passageways may be either open-sided or closed, and are positioned within the combustion chamber in substantial alignment with a respective spray jet of fuel, enabling optimum distribution of the fuel through the combustion chamber for enhanced mixing with air prior to combustion.

Abstract: An internal combustion engine that is structurally similar to a four-stroke engine. The engine comprises at least one cylinder unit, in turn, comprising a cylinder, a piston head that reciprocates within the cylinder, a combustion chamber defined between the cylinder and the front of the piston head, a fuel injector, an oxygen injector, and an exhaust port. The IC engine further comprises a piston rod, one end of which is connected to the piston head and the other end to the crankshaft. The combustion within the combustion chamber is initiated upon the injection of the fuel and the oxygen into the combustion chamber when the piston is at the top dead center. The spent gases are expelled through the exhaust port as the piston returns to the top dead center.

Abstract: A control system and method for operating an engine includes a threshold determination module that determines a plurality of combustion mode thresholds based on the engine speed and engine temperature. The control module also includes a transition module that compares the engine load and the plurality of combustion mode thresholds and changes a combustion mode of the engine in response to comparing the engine load and the plurality of combustion mode thresholds.

Abstract: There is provided an internal combustion engine controller that realizes a reduction in maximum current value and current regulation without sacrificing boost performance.

Abstract: Methods and systems are provided for operating an engine fuel system including a low pressure pump and a high pressure pump. During conditions when direct injection is not requested, a fuel rail pressure is maintained by the low pressure pump and fuel is port injected. Further, a stroke amount of the high pressure pump is adjusted to maintain an outlet pressure of the high pressure pump just below the fuel rail pressure. By maintaining fuel flow within the high pressure pump when high pressure pump operation is not required, and without flowing fuel from the high pressure pump outlet into the fuel rail, the high pressure pump may be cooled and lubricated without affecting the fuel rail pressure.

Abstract: The technique disclosed increases the energy conversion efficiency by means of substantial reduction of friction between the cylinder walls and the associated piston rings. The result is achieved by eliminating the unwanted carbonaceous deposits on cylinder walls and associated piston rings by means of vapor nitric acid (HNO3) delivered to the combustion chambers of an engine. Nitric acid is produced by means of chemical reaction between oxygen (O2) and water vapor (H2O) in air and nitric dioxide (NO2) generated throughout an electrical discharge in the air intake path.

Abstract: A clutch assembly configured for use with a supercharger includes a first shaft supported for rotation within a clutch housing. A pulley is mounted on the first shaft. A clutch rotor is also mounted on the first shaft at a location that is axially spaced from the pulley. A clutch coil is supported within the clutch housing and positioned adjacent to a first face of the clutch rotor. A second shaft is supported for rotation relative to the first shaft and is coaxially aligned with the first shaft. A clutch armature is mounted on the second shaft and positioned adjacent to a second face of the clutch rotor. A supercharger system including the clutch assembly is also provided.

Abstract: An EGR control device is provided in a branched-off pipe portion of a recirculation pipe unit. The EGR control valve is opened during an exhaust gas recirculation period, which is a part of a valve-opening period of an intake valve, so that exhaust gas is re-circulated into a combustion chamber during the exhaust gas recirculation period. As a result, swirl flow of the re-circulated exhaust gas to be formed in the combustion chamber is increased to improve ignitionability and to facilitate combustion of air-fuel mixture.

Abstract: The plasma ignition device includes an ignition plug, a breakdown discharge circuit configured to apply a high voltage to the ignition plug to cause a breakdown discharge in a discharge space in the ignition plug, and a plasma discharge circuit configured to accumulate electric energy supplied from a power supply and applies the accumulated electric energy to the ignition plug as a current to bring a gas in the discharge space into a plasma state so that the gas in the plasma state is injected to a combustion chamber of an combustion engine during the breakdown discharge in order to cause ignition. The plasma discharge circuit includes an energy accumulating section, and an energy supplying section configured to supply the electric energy to the energy accumulating section during a short time period immediately before the breakdown discharge circuit applies the first voltage to the ignition plug.

Abstract: Archery bow adjustment systems that enable adjustment of both the draw weight and the brace height of the bow. The adjustment system includes a plate mounted on an end of a riser of the bow. The plate supports a limb of the bow and is adjustably positionable relative to the riser.

Abstract: The present invention relates to an extension barrel, which comprises an outer tube and a dye coating module. The outer tube is provided at the rear end thereof with a connector portion adapted for connection to a front end of a pneumatic gun. The dye coating module is mounted within the outer tube, so that a bullet projected from the pneumatic gun is coated with dye having a desired color when passing through the dye coating module. As a result, the object hit by the bullet is stained with the color and can be easily identified.

Abstract: An accessory for an archery bow has a C-shaped forearm brace attached to the distal end of a support. The support can be supported on the bow. The brace extends arcuately around a forearm axis at least 180° in order to partially encompass a forearm. The support is mounted in an arcuate slot in the brace and extends outwardly, transverse to the forearm axis. The support can be adjusted to allow angular and linear translation of the forearm brace relative to an adjustment axis that is parallel to the forearm axis. The forearm brace is circumferentially repositionable along the support. The support may be a post with a bearing surface skewed relative to a plane perpendicular to the longitudinal axis. This post may have on opposite sides of the bearing surface, a pair of walls that straddle a peripheral portion of the forearm brace.

Abstract: An air impingement tunnel oven including a baking case having a plurality of walls, the case's interior having high and low pressure zones; a food conveyor spanning between food passage ports; a plenum and air impingement registers combination having pluralities of finger ducts overlying and underlying the food conveyor, each finger duct being attached to and extending from the plenum, and the plenum dividing the baking case's high and low pressure zones; a gas burner supported upon one of the baking case's walls and including a shell and a gas tube within the shell, the shell defining an annulus which opens the baking case's low pressure zone; and an optical flame sensor operatively mounted for detecting burner flame light passing outwardly through the annulus.

Abstract: The present invention relates to a rotating barbeque grill assembly that allows a user to put various food in a carrying frame thereof, parallelly install insert rods at both ends of the carrying frame into position-limit slots on both sides of a metal frame thereof respectively, and insert two transmission shafts into ends of fixed portions on both sides of the metal frame respectively. After the transmission shafts are fixed in the fixed portions, the user can turn on the barbeque apparatus, such that the metal frame can be rotated along the same axis of the two transmission shafts, and the carrying frame then slides from an original position far away from a heat source along the position-limit slots to a position proximate to the heat source, such that the food on both sides of the carrying frame can be heated uniformly and be barbequed to be a delicious dish quickly.

Abstract: An apparatus for cooking comprising a cooking cavity for receiving a food item and a burner positioned within a bottom portion of the cooking cavity for delivering a combustion gas in the cooking cavity which will flow upwardly to heat the vertically-extending interior surface of the cooking cavity. The upward flow of combustion gas within the heating cavity is operable for heating the vertically extending interior surface in a manner such that the food item positioned in the cooking cavity will be cooked at least predominantly by infrared radiation.

Abstract: A gas cooking appliance includes a gas oven cavity for cooking a food item, the gas oven cavity including a top surface and a bottom surface, a lower heat source disposed adjacent the bottom surface of the gas oven cavity, an upper heat source disposed adjacent the top surface of the gas oven cavity, and a controller configured to cycle the upper heat source and the lower heat source for providing heat above and below the food item during cooking, wherein a cycle of the upper heat source is time-dependent, and a cycle of the lower heat source is temperature-dependent.

Abstract: A gas heater includes a support unit, a burner unit, a venting unit and a frame guider. The burner unit includes an ignition unit, a hollow and transparent radiant unit defining a cavity in which the flame guider is positioned, a heat reflector and a burner top cover. The radiant unit comprises a bottom unit with inlet air passages through which an air flow into the radiant unit cavity is created. Then, the frame guider, which has a preset structure such as a spiral and a cone structure and a plurality of guider through-holes, is arranged for guiding and generating a flame pattern which is visible through the radiant unit. The venting unit, which is connected to the radiant unit in an air-tight manner, then provides an air exit. Accordingly, energy utilization is increased and visible flame pattern assemble to real flame can be seen.

Abstract: A tailgate barbeque grill for use in the bed of a pickup truck. The grill slides along rails and is stored in the front portion thereof for transport and is positioned in the rear portion and lowered for use.

Abstract: A fireplace grate that is made from square bar steel and V-bar steel. The V-bars provide improved fire burning characteristics. The position of the V-bar ribs and how the V-bar ribs are made and bent offer these improved characteristics.

Abstract: A machine that improves the management of thermal energy for a residence or other building by serving as both a swimming pool 26 water heater and an attic space 22 ventilator. The heating of air within an attic space 22, resulting primarily from the insolation of the roof surface 24, is exploited to heat water 26. The device consists of an air-to-water heat exchanger coil 28, a fan 30, an air outlet passage 32 between the attic 22 and the outside air with the necessary mounting 90 and weather excluding structure 86. When water heating is not required, the device retains its attic ventilation function in order to reduce the cooling load on the air refrigeration system for the building. The device may be used as either an alternative to a fuel burning or electric powered water heater or as a means to minimize the use and expense of such heaters.

Abstract: A solar tracking system is disclosed. The tracking system includes a tube rotatable around its end-to-end axis. A first support is coupled to the tube at a first location of the tube, and is coupled with a first base. A second support is coupled to the tube at a second location of the tube, and is coupled with a second base. A translation mechanism is coupled with the tube and provided to change the position of the first support relative to the second support.

Abstract: A solar collector comprises an evacuated glass tube (8), an absorbing section (9) comprising a radiation absorbing plate (10), an elongate tube (11, 15) for a working fluid in contact with the radiation absorbing plate (10) and a wire clip (25) for retaining the absorbing section (9) in position in the solar absorbing glass tube (8). The wire clip (25) consists of a single piece wire having a clamping portion (26) for clamping onto the outer surface of the working fluid tube (11, 15) and a pair of resilient side support sections (27) flanking the clamping portion (26). The side support sections (27) extend so that portions thereof engage against the inner surface of the solar absorbing tube (8).