Abstract: A method of engine starting in a gas turbine engine comprises rotating the engine to provide an air flow into a combustor of the engine and injecting fuel into the combustor at a varying rate until the engine is lighted-off. The varying rate of the fuel flow is a function of time and is represented by a curve having at least one high frequency with respect to a light-off time, representing instant changes of the rate for intersecting a light-off zone while reducing a quantity of fuel injected into the combustor. After the light-off occurrence fuel is continuously injected into the combustor to accelerate the engine to a self-sustaining operation condition. This method of the present invention is adapted to find light-off points under various temperature and altitude conditions, thereby advantageously providing a rapid light-off, particularly under cold weather conditions.

Abstract: An apparatus for cleaning floor surfaces and the like includes a cleaning head and a vacuum head to apply water on the surface for a continuous cleaning and vacuum operation. A single water passage of the apparatus is adapted to be connected to an automatic central water supply and drain system to supply water to and withdraw used water from the apparatus alternately through the single water passage in a controlled manner. Fresh water and used water containers are provided for temporarily storing the fresh and used water respectively. A valve device is used to selectively direct the water flow from the single water passage to the fresh water container and water flow from the used water container to the single water passage. Dirt particles are separated from water and air, and are collected in a removable bin for periodic dumping. The apparatus of the invention assures a fully automatic and efficient wet cleaning and vacuuming operation.

Abstract: A synthetic grass surface includes widely spaced rows of ribbons projecting from a flexible backing sheet. Thermal regulating means are attached to the backing sheet in the spaces between the rows of the ribbons. A relatively thick infill layer is disposed on the top of the backing sheet, thereby burying the thermal regulating means and holding the ribbons upright. The infill layer may include a growing medium for plant growth. In one embodiment, electric cables are integrated into the synthetic grass surface in order to heat the surface for de-icing or to maintain plant root warmth. In another embodiment, perforated flexible pipes are integrated into the synthetic grass surface to moisten the surface, thereby cooling the surface when the moisture evaporates. The thermal regulating system of the invention is energy-efficient and economical to install and operate.

Abstract: Swimming goggles or diving masks having a polarized lens of the present invention include a sealed polarized lens unit. The sealed polarized lens unit has a seal member covering and extending beyond the peripheral edge of the laminated polarized lens to protect the polarized lens from de-lamination resulting from encroaching moisture. A non-polarized lens may be optionally affixed in the frame to provide additional protection of the polarized lens, from water impact. Swimming goggles or diving masks having polarized lenses provide a glare-eliminating feature which is particularly useful for water sports where glare significantly inhibits participant vision.

Abstract: A combustion system for a gas turbine engine includes a Catalyst (CAT) combustion sub-system for generating combustion products under a lean premixed fuel/air condition in the presence of a Catalyst and a Dry-Low-Emissions (DLE) combustion sub-system, for generating combustion products under a lean premixed fuel/air condition. Gaseous and liquid fuels are used for the DLE combustion sub-system while only gaseous fuel is used for the CAT combustion system. The engine operates at start-up and under low load conditions with the DLE combustion system and switches over the combustion process to the CAT combustion sub-system under high load conditions. Thus the combustion system according to the invention combines the advantages of DLE and CAT combustion processes so that the gas turbine engine operates over an entire operating range thereof at high engine efficiency while minimizing emissions of nitrogen oxides and carbon monoxide from the engine.

Abstract: A method and apparatus carrying the method for sealing a radial gap between coaxial inner and outer rotating shafts of a gas turbine engine includes using a radial seal as a main seal to seal the gap for a normal engine operation condition, and using an axial seal as a back-up seal for a double seal of the gap. The radial seal provides a seal which meets relatively restrictive leakage requirements for the normal engine operation condition and the axial seal provides a back-up seal which meets less restrictive leakage requirements but is much more tolerant of radial displacement and vibration between the coaxial inner and outer rotating shafts. Thus, an engine operable condition is ensured under abnormal conditions, such as bird strikes, in which the coaxial relationship between the inner and outer rotating shafts are affected by unbalancing forces caused by the bird strike, thereby causing a failure of the radial seal.

Abstract: A combustion system for a gas turbine engine includes a Catalyst (CAT) combustion sub-system for generating combustion products under a lean premixed fuel/air condition in the presence of a Catalyst and a Dry-Low-Emissions (DLE) combustion sub-system, for generating combustion products under a lean premixed fuel/air condition. Gaseous and liquid fuels are used for the DLE combustion sub-system while only gaseous fuel is used for the CAT combustion system. The engine operates at start-up and under low load conditions with the DLE combustion system and switches over the combustion process to the CAT combustion sub-system under high load conditions. Thus the combustion system according to the invention combines the advantages of DLE and CAT combustion processes so that the gas turbine engine operates over an entire operating range thereof at high engine efficiency while minimizing emissions of nitrogen oxides and carbon monoxide from the engine.

Abstract: A tree felling and shaping apparatus is provided with a fully powered and controllable link system which links a tree processor head to a boom that is in turn mounted to a vehicle. The link system includes two powered pivoting joints and a rotary coupling of up to 360° disposed therebetween. Such a combination provides a great convenience for the manipulation of the tree felling and shaping apparatus, not only permitting a maximum angular adjustment of the tree processor head for all directional orientations whether the head is in an upright position for felling trees or the head is in a recumbent position for processing trees, but also performing a universal joint function to freely suspend the tree processor head from the boom without using a conventional uncontrollable universal joint. The present invention improves maneuverability of the tree felling and shaping machines and thereby increases work efficiency.

Abstract: A ball bearing assembly has an outer ring and an inner ring defining the respective outer and inner races, and a plurality of balls separated on the circumference by a cage ring. The inner ring is split into a loaded half and a non-loaded half. The cage lands on the inner ring halves support the cage ring. An annular groove having a non-rectangular cross-section is disposed at the inner ring bore and at the split face. A plurality of radial grooves extend in the split face of one inner ring half to form radial passages between the annular groove and the inner race for directing oil under centrifugal forces collected in the annular groove, into the inner race. Each radial passage has an aperture in the annular groove located in an intermediate section thereof so that the bottom section of the annular groove acts as a reservoir to feed all the radial passages as well as provide a longer residence time for the oil on loaded inner ring surfaces.

Abstract: A gas turbine engine includes an exhaust flow guide attached to the engine exhaust end. The exhaust flow guide is made of a piece of sheet metal curved about the central longitudinal axis of the engine to form a partial portion of a nozzle having curved leading and trailing edges, and side edges. The exhaust flow guide asymmetrically affects the downstream jet noise contribution volume of the exhaust gases discharged from the engine exhaust end to change the jet noise directivity and reduce its power level. The exhaust flow guide can further include additional features such as perforations, corrugated surfaces, reinforcing strips and irregularly shaped trailing edges to further improve the mixing of exhaust gas flow with surrounding fluid flow to further reduce the downstream jet noise contribution volume, thereby resulting in jet noise reduction. The exhaust flow guide according to the present invention also improves attenuation of engine noise generated in the engine and emitted from the engine exhaust end.

Abstract: Counter pressure methods and apparatus for protecting roofs are described, which ensure that indoor air pressure remains negative, that is lower than ambient outdoor pressure during severe windstorms, thus counteracting and thereby reducing the uplift force on the roof surface of a building. In accordance with different embodiments of the invention, one-way valves are provided in openings in the building envelope, such as window openings, or installed over the vents into the roof space so that indoor air flows freely out of the building to a lee zone through the one-way valves while the high air pressure on the windward sides can cause little inward flow because the one-way valves quickly blow closed under wind pressure. According to a further embodiment a Venturi-tube is mounted vertically through or alongside the roof so that its open top forms its own low pressure suction area to draw air from either or both the indoors or the roof space to the same effect.

Abstract: The invention comprises the insertion of anchors into suitably located wall cavities, each anchor being suspended by cables extending up through the wall top and into the roof space; then making fast each anchor by the injection into the cavity above the anchor of a hardening, adhering liquid “plug” of sufficient size and strength, pressing down upon the anchor and strongly adhering to the confining internal surfaces of the cavity. Especially in cases where there are no wall cavities, or none readily accessible, the invention encompasses anchoring the roof to or through the exterior surfaces of suitably located walls by means of long vertical straps; these extend up through the ceiling sufficiently into the roof space, taking the place of the cavity anchors and cables.

Abstract: A flexible partition suspended from a ceiling of a gymnasium or the like, includes a drive cylinder which extends the length of and intermediate of the curtain forming the partition. A cylinder is provided with an internal drive motor, and a reaction device is provided externally of the curtain such that the motor device when activated will drive the cylinder to wind-up the upper and lower portions of the curtain. In one embodiment, the upper portion is a single curtain panel and is attached to the periphery of the cylinder at an axial line. The lower portion includes two spaced curtain panels which are connected to the periphery of the cylinder at diametrically opposite lines thereon. In another embodiment both the upper portion and lower portion of the curtain include two curtain panels, so as to form a full-size double curtain. In such an arrangement, the flexible partition has a spaced-apart double panel configuration at least at its lower portion, to provide a better acoustic insulation.