Abstract: In order to allow fuel to be delivered in a controlled manner into a mixing chamber of a carburetor, a needle is displaced towards a needle seat between an open and a closed position in a clocked manner relative to an intake stroke of the engine such that the amount of fuel that flows into the mixing chamber via a fuel duct is controlled in accordance with the rotational speed and the engine load.

Abstract: An apparatus for producing an ignition spark in an internal combustion engine. The apparatus comprises an inductive ignition device having a primary coil and a secondary coil, flow of current through the primary coil being controlled by an electronic switching element (e.g., a transistor) responsive to a triggering signal. A rotatable body (e.g., the engine flywheel) having detectable features on a periphery thereof is also provided. A sensor device is located adjacent to the rotatable body at a fixed position and is operative to produce an output in response to the detectable features. The apparatus also includes a controller operative to receive an output from the sensor device and responsively produce the triggering signal so as to have a selected dwell time and ignition position.

Abstract: A stator for use in internal combustion engine, the stator comprises a central core having a top surface, a bottom surface, and a plurality of openings extending therethrough. The central core includes a plurality of poles extending outwardly from the periphery of the core. The periphery of the core and the poles are electrically insulated from the central core by an insulating material. Wire is wound on the poles to produce wire coils around each of the poles. The wire coils are electrically connected to lead wires from ignition and/or charging system circuitry or components. Wires from the wire coils and the lead wires are inserted into at least one of the openings in the central core where they are terminated and secured with lead wires from ignition and/or charging system circuitry or components. The wires from the wire coils and the lead wires can also be connected prior to their insertion into the openings wherein the connected wires are secured.

Abstract: The present invention provides a complete ignition and charging system in one assembly for an internal combustion engine that includes a multiple pole radial air gap stator and flywheel assembly with ignition and regulator circuitry mounted to the stator and the flywheel having a plurality of openings extending therethrough.

Abstract: The present invention provides a single piece machined rotor comprising a shell having an upper lip and a lower lip, with a pocket formed between the upper lip and the lower lip for mounting magnets therein. The magnets are fixed in place within the inner sidewall of the rotor with an adhesive and spacers. The spacers are positioned between the magnets and are held in place on the shell of the rotor by fasteners. The spacers may be of any type of non-magnetic material that can absorb the heat of the engine. The rotor also preferably includes triggering protrusions and balancing cutouts machined into the shell of the rotor. The cutouts or grooves may be machined into the inner sidewall or the outer sidewall of the rotor. A plurality of timing teeth used for engine speed sensing maybe machined into the single piece rotor assembly. The present invention also contemplates a method of machining the entire rotor out of a single piece of material.

Abstract: An ignition apparatus for use with an internal combustion engine to produce an electrical spark at a spark ignition device. The ignition apparatus includes triggering circuitry having a processor with stored timing data. The processor receives a signal indicative of the rotational position of the magnet and generates a triggering signal. The triggering circuitry switches between a first mode wherein the triggering signal occurs at a fixed time relative to top dead center and a second mode wherein the triggering signal occurs at a variable time relative to top dead center based on the stored timing data.

Abstract: A capacitive discharge ignition apparatus provides spark advance with engine speed. The ignition apparatus includes triggering circuitry connected to the primary coil of the high voltage transformer. The triggering circuitry produces a triggering signal based on voltage induced in the primary coil by revolution of a permanent magnet. The triggering circuitry is adapted to provide the triggering signal at low RPMs on the trailing edge of a predetermined half cycle. At higher RPMs, the triggering signal shifts to the leading edge of the half-cycle so as to advance the spark.

Abstract: An improved flywheel for use in a small gasoline engine of the type utilized in string trimmers, chain saws, lawn mowers and other such devices. The flywheel comprises a flywheel body including a central hub portion and an integral wheel portion. The hub portion of the flywheel body defines an axial bore extending therethrough in which the engine's drive shaft is received when the flywheel is mounted thereon. An integral key is located in the axial bore for receipt in a corresponding keyway defined in the drive shaft. The key is configured without deep-cut stress reliefs, having opposed side walls extending directly from an inside surface of the through bore.

Abstract: An electric current generation device includes a rotatable rotor including a magnet assembly establishing a magnetic field proximate the rotor. A stator includes at least one set of coils disposed with respect to the rotor so that rotation of the rotor moves the magnetic field with respect to the coils of the coil set to generate electric current flow in the coil set. The coil set includes an impedance component in communication with the electric current flow to limit the rate of increase of electric current flow generated by the coil set as the rotational speed of the rotor increases. The winding direction of at least one coil with respect to the magnetic field may be opposite the winding direction of the other coils with respect to the magnetic field. Two coil sets may be provided wherein the coils of a first coil set are wound so that the output of the first coil set is out of phase with respect of the output of a second coil set.

Abstract: A hacksaw of the type utilizing an elongated blade maintained tension between respective legs of the saw frame includes a cam-actuated blade tensioning mechanism. One leg of the saw frame includes a fixed blade pin for receipt through a mounting hole defined at one end of the elongated blade. The other leg of the saw frame includes a pin carrier having a blade pin for receipt through the mounting hole defined at the other end of the elongated blade. The pin carrier is pivotal between a blade release position and a blade securement position. In presently preferred embodiments, the pin carrier defines a cam follower engaging an elliptically arcuate cam surface defined on a pivotal actuator member. The actuator member may have a lever portion for providing mechanical advantage during its pivotal movement. A releasable lock mechanism is provided to maintain the actuator member, and thus the pin carrier, in the blade securement position during use.

Abstract: A hacksaw of the type utilizing an elongated blade maintained tension between respective legs of the saw frame includes a cam-actuated blade tensioning mechanism. One leg of the saw frame includes a fixed blade pin for receipt through a mounting hole defined at one end of the elongated blade. The other leg of the saw frame includes a pin carrier having a blade pin for receipt through the mounting hole defined at the other end of the elongated blade. The pin carrier is pivotal between a blade release position and a blade securement position. In presently preferred embodiments, the pin carrier defines a cam follower engaging an elliptically arcuate cam surface defined on a pivotal actuator member. The actuator member may have a lever portion for providing mechanical advantage during its pivotal movement. A releasable lock mechanism is provided to maintain the actuator member, and thus the pin carrier, in the blade securement position during use.

Abstract: An improved capacitive discharge ignition apparatus provides a step advance in spark initiation at a predetermined threshold speed. The ignition apparatus includes two trigger circuits electrically connected to a triggering node of an electronic switch device. A triggering signal received from either trigger circuit will cause discharge of an energy storage element through the primary coil of the ignition's step-up transformer. The first trigger circuit is configured to supply an advanced triggering signal only at speeds exceeding the predetermined threshold. In addition, to enhance spark duration, the advanced triggering signal is preferably timed to occur when a sustaining potential is being otherwise induced on the secondary coil of the transformer. The second trigger circuit includes a trigger coil spaced apart from the transformer to provide a delayed triggering signal at speeds below the predetermined threshold speed.

Abstract: An improved capacitive discharge ignition system utilizes a permanent magnet assembly revolving in synchronism with operation of an internal combustion engine to generate spark energy. The relatively high voltage necessary to initiate an ignition spark is produced by application of a capacitive discharge voltage to the primary coil of a step-up transformer. The ignition spark is initiated in timed relationship when a voltage otherwise induced on the secondary coil of the step-up transformer by revolution of the magnet assembly exceeds a characteristic spark sustaining potential. Longer spark duration at lower engine speeds is provided by configuring the discharge circuit such that no more than a negligible current flows in the charge coil during the time in which the sustaining potential is being utilized to maintain the spark. In some exemplary constructions, the discharge voltage may be triggered by a voltage divider network electrically connected across the primary coil.

Abstract: Capacitor discharge ignition system having a microprocessor disposed thereon to control the ignition timing of the system. The system has a generator coil, a primary coil and a secondary coil on the same leg portion of a ferromagnetic core. An electronic circuit associated with the microprocessor includes a capacitor adapted to be charged by an intermediate pulse generated by the charge coil with the leading and trailing pulses thereof being input to control the operation of the microprocessor. The circuit also includes an SCR having its anode-cathode path connected in circuit with the capacitor and primary coil and its gate connected to an output port of the microprocessor which also includes an input port to power the microprocessor from the charge coil. Another port of the microprocessor is adapted to receive timing reference inputs from the charge coil.

Abstract: Disclosed is a method and apparatus for determining weld and coil resistances of a commutator type electric motor armature. The method comprises the steps of determining a resistance ratio for a pair of coils and then determining the weld resistance across a commutator bar and coil connection based upon the resistance ratio.

Abstract: Disclosed is an electronic control system for controlling the operation of an oil burner heating system. The control system comprises a relay circuit having first and second relays. When the relays are closed, an external power source is connected to an igniter and motor. The control system also comprises a relay contact monitor configured to detect whether the relays contacts are welded. The control system also comprises a relay control circuit adapted to energize the relays in response to the call for heat from the thermostat and a signal from the relay contact monitor indicative that the relay contacts are not welded. The relays are configured such that only one relay will open or close with power across its contacts. The control system further comprises an improved flame sense monitor adapted to quickly output signals indicative of flame or no flame when such conditions are present with sensitivity hysteresis and a feature to adjust such hysteresis.

Abstract: Domestic hot water heating control circuit is used in conjunction with a furnace control unit of a hot air furnace system which utilizes a hot water heat exchanger. The hot water control circuit has a diverter valve which is electrically connected to a thermostat which monitors a hot water tank and a fan control circuit for controlling the operation of a comfort fan for the hot air system integrated with the furnace control system. The diverter valve controls the circulation of heated water between the heat exchanger of the furnace and the hot water tank. When the hot water tank thermostat calls for heat, the diverter valve switches a relay to start the furnace and to direct heated water from the heat exchanger of the furnace to the heating coil of the hot water tank. The fan control circuit then operates to shut "off" the comfort fan to prevent cold air from being supplied to the living space in the event that the space thermostat calls for heat.

Abstract: Rotor of a magnetomotive device has a discrete permanent magnetic and a ferromagnetic core disposed within an injection molded, synthetic plastic body in the form of a flywheel. The core is of integral, laminar construction and includes hub and counterweight portions and a pair of radially extending, circumferentially spaced arm portions. At their outer ends, the arm portions terminate in pole shoes with opposed, undercut edges to retain the discrete permanent magnet therebetween. Each of the arm portions has a laterally extending shoulder portion and, at their inner ends, connect to the hub by narrow neck or stem portions which are resiliently flexible. From the center of rotation of the rotor, the stem portions are each disposed along a given radius.

Abstract: Improved pawl assembly for starting mechanisms of small engines mounted on the engine flywheel provided with a bore therein and includes an integrally molded, polymeric pawl, a U-shaped torsion spring and retaining means disposed in the bore of the flywheel. The pawl has a depending shank rotatably fitted into the bore of the flywheel and oppositely extending end portions. The outer end portion, or spur, is adapted to engage a fin or vane of the flywheel to orient the inner end portion, or toe, of the pawl to engage the teeth of the ratchet surface of a pulley type starter. The closed end of the torsion spring is fitted over the shank and urges the pawl to its ratchet engaging position. The spring includes leg portions fitted into the bore of the flywheel and each leg terminates in a laterally extending hook portion adpated to interfit within the retaining means disposed at the end of the bore opposite the end into which the shank is fitted.