Abstract: A class of transportation vehicles for carrying an individual over ground having a surface that may be irregular. Various embodiments have a motorized drive, mounted to the ground-contacting module that causes operation of the vehicle in an operating position that is unstable with respect to tipping when the motorized drive arrangement is not powered. Related methods are provided.

Abstract: A deployable cushion mechanism for a vehicle that provides a cushion deployed in case of vehicle tipping. The cushion is inflated from a folded condition through rapid release of stored energy. Air is allowed to enter the cushion by way of valves or other orifices. Ground contact of the tipped vehicle occurs with the inflated cushion so as to prevent injury to the passenger.

Abstract: A thermal cycle engine having a heat exchanger for transferring thermal energy across the heater head from a heated external fluid to the working fluid. The heat exchanger has a set of heat transfer pins each having an axis directed away from the cylindrical wall of the expansion cylinder, or, alternatively, a set of fins substantially aligned with the axis of the expansion cylinder. The height and density of the heat transfer pins may vary with distance in the direction of the flow path, and the pin structure may be fabricated by stacking perforated rings in contact with a heater head. A ring burner supplements the main combustor for supplying additional fuel to cause additional combustion of the exhaust gas. A regenerator for the thermal cycle engine has a random network of fibers formed to fill a specified volume and a material for cross-linking the fibers at points of close contact between fibers of the network.

Abstract: A class of transportation vehicles for carrying an individual over ground having a surface that may be irregular. Various embodiments have a motorized drive, mounted to the ground-contacting module that causes operation of the vehicle in an operating position that is unstable with respect to tipping when the motorized drive arrangement is not powered. Related methods are provided.

Abstract: A thermal cycle engine having a heat exchanger for transferring thermal energy across the heater head from a heated external fluid to the working fluid. The heat exchanger has a set of heat transfer pins each having an axis directed away from the cylindrical wall of the expansion cylinder. The height and density of the heat transfer pins may vary with distance in the direction of the flow path, and the pin structure may be fabricated by stacking perforated rings in contact with a heater head. Ribs are provided interior to the heater head to enhance hoop strength and thermal transfer.

Abstract: Improvements to personal vehicles including self-propelled and balancing personal vehicles. Ready detachability of a seat, footrest, seat back, control unit, wheels and caster assembly is provided using quick disconnect mechanisms.

Abstract: A system for supporting lateral loads on a piston undergoing reciprocating motion along a longitudinal axis in a cylinder includes a guide link for coupling the piston to a crankshaft undergoing rotary motion about a rotation axis of the crankshaft where the longitudinal axis and the rotation axis are substantially orthogonal to each other. A first guide element is located along the length of the guide link and includes a spring mechanism for urging the first guide element into contact with the guide link. The spring mechanism includes a first spring with a first natural frequency of oscillation and a second spring with a second natural frequency of oscillation. A second guide element is in opposition to the first guide element.

Abstract: A method for controlling the fuel-air ratio of a burner having a blower responsive to a blower drive signal for injecting air into the burner. The method is based at least on the concentration of a gas in an exhaust gas product of a combustion chamber of the burner and includes measuring the gas concentration in the exhaust gas product, deriving a gas concentration signal from the measured gas concentration, determining the fuel-air ratio from the gas concentration signal and the sign of the derivative of the gas concentration signal with respect to the blower drive signal, and controlling the fuel-air ratio by adjusting the air flow rate into the burner. The burner may be, for example, in a Stirling cycle engine.

Abstract: An automatically balancing vehicle having a headroom monitor. The headroom monitor determines the difference between the maximum velocity of the vehicle and the present velocity of the vehicle. An alarm receives a signal from the headroom monitor and produces a warning when the headroom falls below a specified limit.

Abstract: A safety mechanism for a personal vehicle that provides for separation of the motion of a body support from a ground contacting assembly of the vehicle in case of accident. In one embodiment, the body support is attached to the ground contacting module via a slide mechanism that permits the body support to continue upright motion despite overturning of the ground contacting assembly in order to prevent injury to the passenger. Another embodiment provides for coupling of the body support or the ground contacting assembly via either a real or virtual pivot located above the respective centers of mass of the body support and ground contacting assembly.

Abstract: A folded linkage for coupling a crankshaft and a piston undergoing reciprocating linear motion along a longitudinal axis. The folded linkage has a guide link with a first end coupled to the piston. A connecting rod couples the distal end of the guide link to the crankshaft which rotates about an axis that is orthogonal to the longitudinal axis of piston motion and located between the proximal end and the distal end of the guide link. A guide link guide assembly supports lateral loads on the guide link at its distal end. The folded linkage may be applied to couple the compression piston and displacer piston of a Stirling cycle machine to a common crankshaft.

Abstract: A method of combusting fuel and air in a burner of an external combustion engine having a heater head. The fuel and air are combined to form a fuel-air mixture which is characterized by a fuel-air ratio. An exhaust gas product is produced when the fuel-air mixture is combusted in the burner of the external combustion engine. A flame is formed by igniting the fuel-air mixture at a first fuel-air ratio produced by a first air flow rate and a fuel flow rate. The air flow rate is then increased to produce a second fuel-air ratio. The fuel flow rate is also controlled based upon a temperature of the heater head of the external combustion engine. The flame is maintained at the second fuel-air ratio by adjusting the air flow rate based on the fuel flow rate. The external combustion engine may be, for example, a Stirling cycle engine.

Abstract: An anti-tipping mechanism for a vehicle that provides a strut actively deployed by rotation from a retracted position so as to bring a wheel into ground contact to inhibit tipping of the vehicle.

Abstract: A Stirling machine having two pistons coupled to a harmonic crank drive linkage for providing a specified phase relationship between sinusoidal displacements of each piston with respect to a fixed fiducial point. The harmonic crank drive linkage has a primary crankshaft and an eccentric crankshaft mounted internally to the primary crankshaft and coupled via a gear set to counterrotate with respect to the primary crankshaft. The eccentric crankshaft may be cantilevered with respect to the primary shaft, with the pistons of the engine coupled to the eccentric crankshaft externally to the supporting bearings. A flywheel coupled to the eccentric crankshaft provides for operation of the engine with a zero net angular momentum. An intake manifold provides for mixing air and fuel for combustion heating of the engine.