Abstract: A dual-fluid injection system for an internal combustion engine, and an unmanned aerial vehicle (UAV) powered by an engine having the dual-fluid injection system. The dual-fluid injection system comprises a liquid fuel metering device and a fluid delivery device operating in tandem. A gas supply system comprising an air compressor and an air delivery path extending between the air compressor and the fluid delivery device is provided to supply pressurised air to the fluid delivery device. The gas supply system comprises an air compressor and an air delivery path extending between the air compressor and the fluid delivery device. A fuel supply system is adapted to deliver liquid fuel to the liquid fuel metering device. A fuel-air regulator is provided for regulating fuel pressure with reference to air pressure to establish and maintain a requisite pressure differential between the fuel pressure and the air pressure.

Abstract: A fastener driver includes a housing having a handle portion. A motor is positioned within the housing. The fastener driver further includes an air compressor including a compressor cylinder and a compressor piston movable within the compressor cylinder in a reciprocating manner to compress air within the compressor cylinder. The fastener driver further includes a drive train converting torque from the motor to a linear force applied to the compressor piston, causing the compressor piston to move in the reciprocating manner. At least a portion of the drive train extends through the handle portion of the housing.

Abstract: A driving tool having first and second linear motors, a head assembly, a nosepiece and a driver. The first linear motor forms an air compressor and includes a scotch yoke mechanism for translating a first piston in a first cylinder. The scotch yoke mechanism includes a crank arm, a crank arm roller, which is coupled to the crank arm, and a connecting rod having a roller slot into which the crank arm roller is received. At least a portion of the roller slot is configured to vary an output rate at which the connecting rod translates along a translation axis relative to an input rate at which the crank arm roller moves in a direction that is parallel to the translation axis.

Abstract: An impulse motor for a hand held hammer machine comprises a housing (10) with a cylinder (11) therein, in which a reciprocating drive piston (40) via a gas cushion in a working chamber (44) of said cylinder (11) repeatedly drives a hammer piston (15) to impact on and to return from a tool (20) carried by the machine housing (10). The drive piston (40) has an axially protruding reduced diameter damping piston (50) thereon adapted to prevent piston encounter collision by arresting the return movement of said hammer piston (15) towards the drive piston (40) in a cooperating damping cylinder (51) provided on the hammer piston (15). The damping piston (50) has two diameterical steps (64,65) formed thereon, of which an outer step (64) is long and has a clearance relative to said damping cylinder (51) enabling during arresting a braking action therebetween by gas friction in said clearance.

Abstract: A vacuum-compression type percussion power tool comprises a housing (12), a cylinder (14) fixed in the housing, a piston (16) reciprocating in the cylinder (14) from a reciprocating drive mechanism such as a crank mechanism (18) driven by an electric motor, or any other suitable drive, a working tool (24) installed in the front part of the power tool, and a floating striker (34) which slides inside cylinder (14) in a space between a tail portion (26) of working tool (24) and the lower end of the piston. The power tool has a sealed auxiliary chamber (54, 56) , which is formed by a hollow casing (48) which surrounds the cylinder, and a space below striker (34). The auxiliary chamber is connected to a main working chamber (38), which is formed between the piston and the striker, through a set of compensation holes (44) and a set of idle-stroke holes (46). The power tool has a pumping chamber (27) which is formed in the upper part of cylinder (14) between the upper end face of piston (16) and a closed cover (17).

Abstract: A vacuum-compression type percussion power tool comprising a housing (12), a cylinder (14) fixed in the housing, a piston (16) reciprocating in the cylinder (14) from a reciprocating drive mechanism such as a crank mechanism (18) driven by an electric motor, or any other suitable drive, a working tool (24) installed in the front part of the power tool, and a floating striker (34) which slides inside the cylinder (14) in a space between a tail portion (26) of the working tool (24) and the lower end of the piston.

Abstract: A vacuum-compression type percussion power tool comprising a housing (12), a cylinder (14) fixed in the housing, a piston (16) reciprocating in the cylinder (14) from a reciprocating drive mechanism such as a crank mechanism (18) driven by an electric motor, or any other suitable drive, a working tool (24) installed in the front part of the power tool, and a floating striker (34) which slides inside the cylinder (14) in a space between a tail portion (26) of working tool (24) and the lower end of the piston. The power tool has a sealed auxiliary chamber (54, 56) which is formed by means of a hollow casing (48) which surrounds the cylinder, and a space below the striker (34). The auxiliary chamber is connected to a main working chamber (38), which is formed between the piston and a striker, through a set of compensation holes (44) and a set of idle-stroke holes (46). A check valve (51) is installed in the wall of the auxiliary chamber.

Abstract: The rotary output of the power source of an impact device is converted to reciprocation of a body, preferably having a resilient coupler, which drives a ram into impacting in an improved rotary-to-reciprocative motion converter including a crankshaft operatively interconnected to reciprocate the body. The converter includes a crankpin bearing, a flat bearing surface secured normal to the reciprocation on a connecting rod or directly on the body, and a constraint spring to hold the flat bearing surface in contact with the bearing during operation. The improved converter provides reciprocation free of angular motion of connecting rods and irregular motion within clearances between moving elements to significantly reduce extraneous harmonic vibrations and energy losses therefrom.

Abstract: A fluid pressure amplifier for intensifying fluid pressure, the amplifier comprising a housing including a hydraulic fluid reservoir therein. A first chamber includes a slave piston mounted for reciprocation therein and for abutting engagement with a workpiece. A hydraulic fluid path extends intermediate the reservoir and the first chamber and a second chamber lies in the path intermediate the first chamber and the reservoir and includes check means intermediate the first and second chambers. A third chamber includes a fluid intensifier piston having a head end and a tail end, the head end being mounted for reciprocation in the third chamber and the tail end being mounted for reciprocation in the second chamber, the head end of the piston having a larger diameter than the tail end. Gas admittance means admit a pressurized gas to a gas path which lies intermediate the gas admittance means and the reservoir.

Abstract: An apparatus for generating a series of seismic acoustic pulses in a body of water. The series is characterized by having continuously-variable, non-repetitive time intervals between successive pulses during a continuous seismic recording. The preferred generator is an air gun comprising a variable-speed motor with a rotating cam for actuating a sleeve valve which alternately opens and closes exhaust ports in a high-pressure chamber. As the valve repeatedly opens, jets of high-pressure air are impulsively expelled into the surrounding water, thereby generating an underwater acoustic pulse train.

Abstract: A pneumatic pump adapted primarily as a left ventricular heart assist device includes a flexible bladder with a rigid housing. A pneumatic driver applies rhymical pulses between the bladder and the housing to repetitively collapse the bladder and establish a pumping action through the bladder, in conjunction with check valves in the inlet and outlet to the bladder. Between the driver and the pump there is provided a pneumatic pulse limiter which includes a flexible diaphragm isolating the driver from the pump. Pulses from the driver are transmitted to the pump only through the flexible diaphragm and the diaphragm is constrained to move only within established limits. Regardless of the magnitude of the pulse from the driver, the maximum pulse applied to the pump cannot exceed that corresponding to the maximum displacement of the diaphragm.Between successive pulses, the portion of the system between the driver and the flexible diaphragm is depressurized.

Abstract: A fluid pressure amplifier for intensifying fluid pressure, the amplifier comprising a housing including a gas-hydraulic interface piston; a first chamber includes a slave piston mounted for reciprocation therein and for abutting engagement with a work piece. A hydraulic fluid path extends intermediate the interface piston and the first chamber so as to apply hydraulic pressure thereto. A second chamber is disposed in the path intermediate the first chamber and the interface piston and includes a check valve in the path intermediate the second chamber and the first chamber. A third chamber, includes a fluid intensifier piston having a head end and a tail end, the head end being mounted for reciprocation in the third chamber and the tail end being mounted for reciprocation in the second chamber. The head end of the intensifier piston has a larger diameter than the tail end and is exposed to gas pressure while the tail end is exposed, in the second chamber, to hydraulic pressure.