Abstract: A method of operating a free piston engine of the present invention provides a piston including a piston head reciprocally disposed within a combustion cylinder, a plunger head reciprocally disposed within a hydraulic cylinder, and a plunger rod interconnecting the piston head with the plunger head. The plunger head and the hydraulic cylinder define a variable volume pressure chamber on a side of the plunger head generally opposite the plunger rod. A supply of hydraulic fluid is pulsed from a high pressure hydraulic accumulator into the pressure chamber during a beginning portion of a compression stroke to cause the piston head to move toward a top dead center position. The high pressure hydraulic accumulator is then decoupled from the pressure chamber.

Abstract: An internal combustion powered tool, such as a nail or fastener driver, and a control system, spark source, and rotary valve for use in an internal combustion powered tool are disclosed. The tool may include, for example, a cylinder and a piston reciprocally moveable within the cylinder. A combustion chamber is defined at one end of the cylinder, with the piston comprising a portion of one end of the combustion chamber. The tool may have a fastener driver associated with the piston, and a magazine for feeding fasteners into registration with the driver. A fuel flow passageway extends between a fuel source and the combustion chamber, and a metering valve controls the flow of fuel to the combustion chamber. A spark source within the combustion chamber is provided for igniting the fuel, and an intake and exhaust valve that includes a pair of diametrically opposed apertures is provided.

Abstract: A detonating impact tool, such as a nailer, has a manual recycler. The recycler has a pump housing which is moved through a stroke to purge exhaust combustion gases from the tool. The tool provides pump housing which operates with a significantly reduced stroke as compared to previous manual recyclers. The tool has a return spring which automatically returns the piston and its associated driver to a rest position part way along a cylinder and forward of a vent port after each detonation. In one embodiment of the invention a restriction in the cylinder wall temporarily holds the piston at its rest position. The stroke reduction system reduces the length of travel of the pump section for easier and faster tool performance while the more compact design enhances market appeal. The reduced stroke facilitates embodiments of the invention wherein the pump housing is actuated by a squeeze lever.

Abstract: A free piston internal combustion engine includes a housing with a combustion cylinder and a compression cylinder. A fluid inlet port is disposed in communication with the compression cylinder for transporting a pressurized fluid into the compression cylinder. A piston includes a piston head reciprocally disposed within the combustion cylinder, a compression head reciprocally disposed within the compression cylinder, and a plunger rod attached to each of and interconnecting the piston head and the compression head. The compression head includes a plurality of radially extending vanes which are positioned to be at least intermittently disposed in association with the fluid inlet port, whereby pressurized fluid which is transported into the compression cylinder from the fluid inlet port causes the piston to rotate.

Abstract: The present invention relates to methods employing internal combustion fastener driving tool for driving a fastener and for starting a flooded tool. A method for starting a flooded tool includes: compressing the tool against an object to slide a piston axially within a piston housing to purge fuel and air from a combustion chamber, and to close a conduit between a metering chamber and a source of gaseous fuel; latching closed the conduit; drawing air into the combustion chamber by releasing the tool from the object; purging the air and any residual mixture of fuel and air from the combustion chamber by compressing the tool; repeating the drawing and purging steps one or more times; and opening the fluid communication between the fuel source and the combustion chamber.

Abstract: The present invention relates to a shuttle valve for delivering fuel for internal combustion in a fastener driving tool.

Abstract: The present invention relates to a system for delivering a metered amount of fuel for internal combustion in a fastener driving tool. The fuel metering system includes a port for fuel, a regulator, and a shuttle valve. The shuttle valve particularly includes a metering chamber housing, a metering chamber defined by the metering chamber housing, a combustion check valve, and one gating valve. The metering chamber and the gating valve can be arranged and configured to provide asynchronous fluid communication between the metering chamber and combustion chamber, or between the metering chamber and the regulator. The combustion check valve is arranged and configured to prevent fluid flow from the combustion chamber to the metering chamber.

Abstract: A free piston internal combustion engine is under the control of micro-computer, and according to the two stroke cycle principle operating. Piston retracts by a spring. A hydraulic system outputs the power. Starting method is, when the piston is held at the end of the compression stroke, some fuel and compressed air inject into combustion chamber, perform a well-mixed compressed mixture, and then ignite for a explosion so that the engine begins the normal operating cycles.

Abstract: A combustion powered tool having a self-contained internal combustion power source constructed and arranged for creating a combustion for driving a driver blade to impact a fastener and drive it into a workpiece includes a housing having a main chamber enclosing the power source, a combustion chamber defined within the main chamber, an air flow enhancing device disposed in the combustion chamber for enhancing the flow of air therein, and a supplemental air flow enhancing device disposed externally of the combustion chamber and within the housing for forcing air past the combustion chamber as a cooling mechanism.

Abstract: A fuel system is provided for a combustion-powered tool having a self-contained internal combustion power source with a combustion chamber, and constructed and arranged for driving a drive blade to impact a fastener and drive it into a workpiece. The tool includes a housing having a main chamber enclosing the power source and having a first end adjacent a nosepiece wherein the fasteners are positioned prior to driving, and a second end opposite the first end and adjacent the combustion chamber. A fuel cell chamber is in communication with the main chamber and has a first chamber end corresponding to the first end of the main chamber and a second chamber end corresponding to the second end of the main chamber.

Abstract: The invention relates to a method for the cold start of a free-piston diesel engine, comprising a cylinder having a combustion room therein and an air inlet, fuel supply and combustion gas outlet connected thereto, and a piston movable within the cylinder and limiting one side of the combustion room. Energy is supplied to the piston to compress air supplied through the inlet by reducing the combustion room, whereafter fuel is injected to allow the fuel-air mixture to ignite by spontaneous combustion. So much compression energy is delivered to the piston that the combustion room is reduced to a volume of less than 3% of the combustion room volume when the outlet is closed. The corresponding free-piston engine has a dead volume of less than 3%.

Abstract: A free piston engine having a fluid pressure unit which includes a cylinder and a piston arranged within the cylinder and reciprocating therein between the bottom dead center and the top dead center. The piston includes a plunger-shaped piston extension cooperating with the fluid pressure unit. This fluid pressure unit is equipped with an auxiliary member for moving the piston in a direction to its bottom dead center. This auxiliary member includes a connecting channel adapted to communicate a liquid pressure source with a room in which the plunger-shaped piston extension extends and which room is closed on one side by an axial face of the piston extension which is directed such that, by pressure loading the axial face, the piston is moved towards the bottom dead center. The axial face is formed on a ring slidably arranged on the plunger-shaped extension. The plunger-shaped extension includes a stop adapted for engagement by the ring when it is moved for displacing the piston to its bottom dead center.

Abstract: A free-piston engine having a fluid pressure unit, comprises a cylinder and a piston arranged therein. The piston is equipped with a plunger-shaped extension including a working section having a room bordered by a first axial face of the plunger-shaped extension and the volume of which is reduced when the piston makes an expansion stroke, and to which a discharge channel to a high pressure accumulator and a supply channel from a supply reservoir connects. The piston further includes a compression section including a chamber having a first chamber portion enclosed by a second axial face in the bottom dead center of the piston and a second chamber portion bordered by a third axial face.

Abstract: For a combustion-powered, fastener-driving tool, a combined ignition and fuel system comprises a battery, two normally opened switches connected to the battery, namely a head switch and a trigger switch, a fuel injector including a solenoid and an associated circuit controlling the fuel injector to enable the fuel injector to inject a combustible fuel for a first time interval, a circuit for producing ignition, and a circuit for monitoring the head and trigger switches, for disabling the injector-controlling circuit if the trigger switch is closed while the head switch is opened or if both switches are opened, for enabling the solenoid if the trigger switch is closed while the head switch is closed, for enabling the ignition-producing circuit after a second time interval succeeding the first time interval, and for disabling the ignition-producing circuit when the injector-controlling circuit is disabled as mentioned.

Abstract: For use in a combustion-powered, fastener-driving tool having a combustion chamber, a source of a combustible fuel, and a switch that must be closed to enable the tool, a fuel system comprises a fuel injector, which includes a normally closed, solenoid-energized valve between the fuel source and the combustion chamber, and an electronic circuit responsive to the switch for energizing the solenoid to open the valve when the switch is closed and for deenergizing the solenoid after a time interval. A resistive-capacitive network defining the time interval includes a first resistor, a second resistor arranged to be selectively connected in parallel therewith, a thermistor connected in parallel therewith, and a variable resistor connected to the parallel resistors. Another network effects a time delay between closure of the switch and energization of the solenoid. Optionally, another network varies the time interval in response to ambient pressure.

Abstract: A combustion gas powered tool includes a member defining a part of cylindrical combustion chamber having an axis. A piston is movable in a direction along the axis of the combustion chamber. The piston defines the combustion chamber in conjunction with the member. A mixture of air and fuel is generated in the combustion chamber. The air-fuel mixture in the combustion chamber is burned to drive the piston. An orifice grille extends in the combustion chamber, and is parallel to the axis of the combustion chamber.

Abstract: In a combustion-powered, fastener-driving tool, a cylinder body mounted fixedly within a housing structure has a combustion chamber defining an axis. A valve sleeve functions to open and close the combustion chamber. A piston operative within the combustion chamber and a driving blade moveable with the piston function to drive a fastener into a workpiece. An improved linkage for moving the valve sleeve includes a workpiece-contacting element and a pair of arms attached to such element and disposed alongside the cylinder body and the nosepiece. An improved, one-piece, interlocking member prevents a trigger from being actuated unless the combustion chamber is closed. Thus, a simple, compact, lightweight tool is provided.

Abstract: An internal combustion actuated fastener driving device in which a simple container supply of fuel under pressure carried in a handle portion of the portable housing assembly feeds to a supply chamber controlled by an actuating valve operable in response to a manual acuating procedure to be spring moved into an operative position. The movement of the actuating valve into its operative position communicates a previously formed charge of gaseous fuel under pressure in a separate charge chamber with a series of nozzles so as to discharge in jet stream formations which aspirate fresh air through inlets to mix therewith in a mixing chamber for passage into a combustion chamber in open condition controlled by a main valve. The main valve moves under spring bias into a closed position in response to the depletion of gaseous fuel pressure within the charge chamber in timed relation with the crowding of the spent gases from the combustion chamber by the new combustible mixture.

Abstract: A portable, internal combustion powered work device, such as a device for setting or driving fastening elements into a receiving material, includes a combustion chamber (9) wherein an air-fuel mixture is ignited. A guide cylinder (8) and a piston (7) are axially displaceably guided within the combustion chamber. When the air-fuel mixture is ignited, the piston (7) is driven and, in turn, drives a fastening element into the receiving material. Following the ignition of the air-fuel mixture and the driving of the fastening element, the combustion chamber volume is reduced to approximately zero, whereby a purely mechanical clearing of the combustion chamber is effected without the necessity of an additional flushing air flow.

Abstract: This gas pressure generating engine has a totally unconnected piston running between a combustion chamber and a rebounding volume. The piston uncovers the outlet port after moving a short distance from the combustion chamber and utilizes the rest of the piston's long stroke to draw in new air; and after turning around at the stroke's end to pump to the outlet a large part of the drawn-in air. The remainder of the drawn-in air is further compressed for combustion. The stroke of the piston is restricted only by the energy it receives from the combustion chamber. The rebounding volume's pressure is adjustable to adjust the pressure-volume ratio of the outlet gas. A tuned valve in the outlet and a tuned blowdown tube maximize gas momentum scavenging of the combustion chamber to improve the efficiency and extend the operating range.

Abstract: For a combustion-powered tool, an ignition system is powered by a battery and is arranged so that a sudden discharge of a capacitor, as charged via an oscillator, produces a spark at a spark gap of a spark plug, so that the oscillator is enabled if a trigger switch is closed while a head switch is closed, but not if the trigger switch is closed while the head switch is opened, and if a battery voltage, as monitored, is not less than a reference voltage, and so that a silicon-controlled rectifier, which is arranged to produce a sudden discharge of the capacitor, is switched to a conductive state if the capacitor voltage, as monitored, and is not less than a reference voltage. The head and trigger switches, which are photoelectric, are polled intermittently to determine whether they are closed. Predominantly, solid-state components are used.

Abstract: A combustion gas powered fastener driving tool includes inlet and outlet openings through which the combustion gases are discharged from a combustion chamber. These openings are located above the uppermost driving position (top dead center) of a slidable piston, so that an air and fuel mixture is fully trapped in the combustion chamber until after it is combusted. Since an outflow of the unburnt air and fuel mixture is completely prevented, the rate of fuel consumption of the fastener driving tool is high and there is no danger of accidental explosion of unburned fuel even when the fastener driving tool is used in a badly ventilated working place or site. An electric fan for forcing fresh air into the combustion chamber is disposed outside the cylinder and isolated from high temperatures. The fan is durable in structure and reliable in operation.

Abstract: Apparatus for generating hot combustion gases and steam including a piston block with a piston reciprocally mounted in a bore therethrough having solenoids and sensors for selectively introducing hydraulic fluid into the bore on the first side of the piston to move the piston. Inlets and sensors for selectively introducing air and fuel into the combustion chamber comprising a portion of the bore and to initiate combustion are also provided. The hydraulic fluid used to move the piston is introduced into the bore in a discharge chamber in the bore on the second side of the piston, vaporized and exhausted into a well through an exhaust valve. The exhaust valve is biased toward the closed position by a pneumatic cylinder which resists the force of combustion.

Abstract: A free-piston engine in which combustion gas is conducted around a piston for a short time during the expansion stroke. The resulting lowered pressure enables intaking in the final part of this stroke. Pressure from the gas conducted around the piston serves as the piston rebounding force and as the engine output.

Abstract: A portable power tool comprising a housing defining a combustion chamber and a cylindrical chamber having a reciprocating piston therein. The combustion chamber has an opening defined by a valve seat closable by a poppet valve and serving as an inlet at one side for unburnt gases or vaporized fuel admitted under pressure and an output at an opposite side for spent gases. An ignition assembly is provided for igniting unburnt fuel in the combustion chamber which is synchronized with the closure of the poppet valve. The combustion chamber and the poppet valve are shaped and arranged such that unburnt fuel admitted through one side of the valve seat opening will sweep the spent fuel of a preceding ignition cycle from the combustion chamber out through the other side of the valve seat opening.

Abstract: A portable power tool comprising a housing defining a combustion chamber and a cylindrical chamber having a reciprocating piston therein. The combustion chamber has an opening defined by a valve seat closable by a poppet valve and serving as an inlet at one side for unburnt gases or vaporized fuel admitted under pressure and an outlet at an opposite side for spent gases. An ignition assembly is provided for igniting unburnt fuel in the combustion chamber which is synchronized with the closure of the poppet valve. The combustion chamber and the poppet valve are shaped and arranged such that unburnt fuel admitted through one side of the valve seat opening will sweep the spent fuel of a preceding ignition cycle from the combustion chamber out through the other side of the valve seat opening.

Abstract: An unsymmetrical and balanced free piston engine of economical construction in which the engine cylinder requires no liner. A housing surrounding the cylinder is opened for cylinder machining and is adapted for space-saving vertical mounting. It has an open-sided base portion through which an engine piston may be installed and removed for servicing, which lowers the initial cost of manufacturing and the later cost of maintenance, as compared with earlier engines of the same engine type.

Abstract: A housing partially defines a combustion chamber. A movable piston partially defines the combustion chamber. An air and fuel mixture is generated in the combustion chamber. The air and fuel mixture is ignited in the combustion chamber. An obstacle member is fixedly disposed in the combustion chamber. The obstacle member serves to generate turbulence in an unburned portion of the air and fuel mixture after the air and fuel mixture is ignited. Fuel may be injected into at least two points in the combustion chamber.

Abstract: A fastener driving tool powered by internal combustion of an air/fuel mixture. The tool body contains connected upper and lower coaxial cylinders. The upper cylinder is provided with a piston assembly and is connected by a one-way valve to a combustion air chamber. The lower cylinder contains a piston/driver assembly and is surrounded by and connected to a return air chamber. The upper cylinder piston assembly and the lower cylinder piston/driver assembly, when in their normal unactuated positions, define therebetween a combustion chamber provided with an ignition device.

Abstract: A purging and recharging system improves the repeating of detonations from a detonation device 10 having a detonation chamber 20 separated from an ignition chamber 25 by a detonation plate 22 having an opening 23 through which a flame jet can pass from ignition chamber 25 to detonation chamber 20. A differential piston 30 driven by a detonation in a differential cylinder 31, 32 around detonation chamber 20 affords a fluid passageway between differential piston 30 and detonation chamber 20. On a power stroke, differential piston 30 compresses recharging air and draws in cooling and exhaust purging air to surround detonation chamber 20. On a return stroke, differential piston 30 forces cooling and purging air into detonation chamber 20 and then admits compressed recharging air into detonation chamber 20.

Abstract: An internal combustion hydraulic engine is powered by compression and ignition of pressurized fuel to pressurize hydraulic fluid. The timing and operation of the engine is controlled by a hydraulically driven distributor valve. A pair of starting valves are employed to hydraulically actuate the distributor valve for starting the operation of the engine. An intensifier pump powered by the engine and coordinated with the operation of the engine is employed to pressurize the fuel which is combusted for powering the engine.

Abstract: A free piston engine includes speed control means which provide a wide range of engine speed control for selective connection and use of the engine with any one of a number of different types of energy absorbing devices. The desired control is achieved by use of two bounce chambers and a double-acting bounce piston unit specifically located at an intermediate position along the axis of reciprocation of the piston rod assembly of such an engine, i.e. between a power piston at one end of the piston rod and a connecting means at the other piston rod end for driving connection of the piston rod assembly with a movable member (e.g. reciprocating compressor piston or reciprocating electric generator member) of the selected energy absorbing device. The control means further includes at least one pair of variably adjustable bounce chamber pressure control valves (one for each bounce chamber).

Abstract: An efficient, portable, easy to operate tool employing a linear motor is disclosed that is powered by the gases produced from the internal combustion of a fuel and air mixture. A supply of liquified gas stored under pressure in a cylinder provides the source of power. The linear motor is slidably mounted within a cylinder to move reciprocally downwardly and upwardly through a driving and return stroke. A combustion chamber is formed at the upper end of the cylinder. A spark plug powered by a piezo-electric firing device is located within the combustion chamber. The combustion chamber features a turbulence generator, such as a fan, driven by an electric motor which is continuously in operation when the tool is in use. A main valve mechanism actuated by a set of lifting rods that are moved upwardly and downwardly when the tool is moved towards and away from the workpiece, is used to control the opening and closing of the combustion chamber and to control the flow of fresh air through the combustion chamber.

Abstract: A portable gas-fired fastener driving tool in which the tool cannot be operated until the combustion chamber is closed and the combustion chamber cannot be reopened after ignition until the trigger is released. The operation of the trigger is permitted by the actuation of a bottom trip mechanism which controls the movement of a sleeve mechanism that regulates the opening and closing of the combustion chamber. During the driving action, the combustion gases above the piston are evacuated through valved openings in the cylinder adjacent the bottom thereof. The piston contacts a bumper at the bottom of its travel and the difference between the vacuum in the combustion chamber and atmospheric air acts to return the piston to its driving position.

Abstract: An efficient, portable, easy to operate fastener applying tool is disclosed that is powered by the gases produced from the internal combustion of a fuel and air mixture. The tool uses an internally contained supply of liquified gas stored under pressure in a cylinder. Air is drawn in from outside the tool and mixed with fuel in a combustion chamber with the aid of a fan powered by an electric motor. A spark plug powered by a piezo-electric firing device is used to ignite the air-fuel mixture in the combustion chamber. Combustion gases are discharged from the cylinder at the end of the driving stroke and air is supplied to the lower face of the piston to return it to the original position. An interlock mechanism is provided to insure that the tool cannot be operated until the combustion chamber is closed and the combustion chamber cannot be reopened after ignition until the trigger is released.

Abstract: An internal combustion apparatus is disclosed having a linear output. A metered quantity of gas fuel is transferred between a cylinder head and the disc of a plunger reciprocable in a principal chamber between top and bottom end of stroke positions. In the displacement of the plunger to its bottom end of stroke position air and fuel are intimately mixed in a one-way flow path around the disc including nonparallel and/or burred orifices in a perforate plate attached to the plunger. The fuel may be liquefied gas fuel in which case it may be vaporized by the combustion gases exhausted from the principal chamber to the surroundings through an annular exhaust zone coaxial of throttle passageways for carrying fuel from the metering piston to the principal chamber. Alternatively, a pressurized gas fuel may be used in which case the pressurized gas is utilized in the operation of the plunger.

Abstract: A percussion apparatus, for example for driving nails or staples, having an auxiliary piston which when released thrusts a main operating piston to an intermediate position. The auxiliary piston transfers a metered quantity of gaseous fuel together with combustion supporting air to a space between the main piston and cylinder head separating the auxiliary piston cylinder from the main piston cylinder. The explosive mixture in the space is then ignited and the main piston is thrust in a first direction displacing a driver member and simultaneously the auxiliary piston is thrust in the opposite direction to its initial position where it is retained until released to start another operating cycle; the main piston automatically returns to its initial position as the combustion gases are exhausted to the atmosphere.

Abstract: The invention relates to the safety against shocks in a free piston machine.The engine section of a unit operating according to the Diesel cycle and air-cooled runs the risk of supplying an important amount of energy to the piston, so that the latter might knock against the cover of the bounce cylinder or chamber. The constructional elements (stroke and diameters) of the machine are calculated in a manner such that their ratios cause, as a result of expansion, the ignition to stop before the dead point on the bounce section side (curve 12) knocks against the cylinder.Application: compressor with 2-stroke Diesel engine, having a one-piece movable member, and air-cooled.

Abstract: A two piston hydraulic fluid separated internal combustion cylinder system utilizing a cylinder having fuel inlet ports, ignition means, a viewing window, a filling plug; a first piston, hydraulic fluid cushion and a smaller piston which may be connected to a crankshaft.

Abstract: A variable stroke alternating compressor is disclosed wherein a movable one-piece free piston 1 serves at the same time as an engine piston 2, a compressor piston 3, and a bounce piston 4; the elements are integrated; the assembly is dynamically balanced, cooled, and insulated. It has no movable mechanical connections. The elements thereof have motions which are all controlled by the travel of the free piston.

Abstract: The nozzle is provided with a bar which may be rotated to and fixed at various angular positions. The bar has a longitudinally extensive cut away portion, providing a fuel passage. Varying the angular position changes the turning velocity of the vortex-type jet issuing from the passage. The effect of varying the shape of the fuel passage is also described. The purpose of variation is to cause fuel to be properly retained on the saucer shaped top surface of the impact block until the piston strikes the surface, causing the fuel to atomize and be uniformly dispersed to enhance complete combustion of the fuel.

Abstract: An illustrative system is disclosed for use as a rotary-drive engine, utilizing combustible fuel and a hydraulic system of energy conversion. An engine block defines a pair of expansion cylinders (combustion chambers) and an associated concentric pair of hydraulic chambers. The chambers matingly receive unitary piston structures for phase-opposed reciprocal movement.The hydraulic working chambers communicate with each other and can exhaust high pressure fluid through a control valve structure for drive power. Exhausted fluid is replaced in volume by low-pressure spent fluid. The body of the fluid contained in the hydraulic working chambers along with the piston means and springs connected to the engine block define an oscillatory system which is resonant at the operating frequency. That consideration, along with the absence of lateral loads on the pistons, results in relatively high efficiency.

Abstract: An efficient, portable, easy to operate tool employing a linear motor is disclosed that is powered by the gases produced from the internal combustion of a fuel and air mixture. A supply of liquified gas stored under pressure in a cylinder provides the source of power. The linear motor is slidably mounted within a cylinder to move reciprocally downwardly and upwardly through a driving and return stroke. A combustion chamber is formed at the upper end of the cylinder. A spark plug powered by a piezo-electric firing device is located within the combustion chamber. The combustion chamber features a turbulence generator, such as a fan, driven by an electric motor which is continuously in operation when the tool is in use. A main valve mechanism actuated by a set of lifting rods that are moved upwardly and downwardly when the tool is moved towards and away from the workpiece, is used to control the opening and closing of the combustion chamber and to control the flow of fresh air through the combustion chamber.