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: 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: In a method of regulating the supply of driving-medium per stroke cycle to a pile-driving rammer the driving-medium supply per stroke cycle is adjusted for driving piles into the ground in the shortest time in dependence upon the value, measured by at least one scanner, of the result of at least two preceding strokes of the rammer and more in accordance with the driving-medium supply adjusted during the stroke which gave the better result.In order to improve the energy transfer from a diesel hammer upon the pile apart from a basic fuel per combustion cycle at least one substance affecting the combustion velocity is supplied to the Diesel hammer in accordance with the pile-driving operation.

Abstract: A diesel pile driver with impact atomization of the fuel between pile driver piston and an impact member as well as with a fuel injection pump and an injector nozzle, which sprays fuel onto the impact member in the pile driver cylinder.

Abstract: A cylinder piece for a cylinder of a pile driving ram comprises inlet and outlet ports and at least two guide girdles for supporting guide members adapted to co-operate with a guide stay of a guide frame.This considerable cylinder piece can be readily made in such a way that the possibility of unexpected damage is reduced and that it has a long lifetime, in that a core of the cylinder piece is made from ferritic-perlitic nodular cast iron with at least two substantially cylindrical guide girdle faces for guide girdles and in that at least two guide girdles are clamped around the guide girdle faces, which guide girdles are each mainly formed by a ring from predominantly ferritic nodular cast iron with a cylindrical bore.

Abstract: In a Diesel pile-driving ram comprising a combustion cylinder, a striker extending into the combustion cylinder, a piston housed in the combustion cylinder and a fuel injector for the supply of fuel between the impact surfaces of the piston and the striker, the impact surface of the striker is orientated in such a manner towards an annular precombustion chamber of a compression space provided between the piston and the striker, that the fuel atomized by impact ignites in the precombustion chamber. Said fuel, however, has too little air in said chamber in order to ignite immediately. The ignition is delayed for a moment but not too strongly because the precombustion chamber communicates with the main combustion chamber through an ample, annular passage of short length in an axial direction.

Abstract: A cylinder piece for use as the cylinder in a pile driving ram is provided with inlet and outlet ports and at least two guide girdles for supporting guide members adapted to cooperate with at least one guide stay of the guide frame. The core of the cylinder piece is made by forging and has at least two substantially cylindrical guide girdle faces for guide girdles, with the guide girdle being formed by a ring having a cylindrical bore being shrunk around a guide girdle face.

Abstract: In a rammer a piston housed in a combustion cylinder strikes with its impact surface the adapted impact surface of a striker. When the impact surfaces are spherical or flattened the piston may strike against the cylinder wall, as a result of which the cylinder surfaces and the piston surfaces wear off strongly. In accordance with the invention the impact surfaces have a tangential cone having an obtuse apex so that on the one hand a sufficient centering of the piston with respect to the striker is obtained and on the other hand the risk of cracking in piston and striker is prevented.

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 impact action mechanism of the type wherein the impact member is propelled by a combustible matter combusted in the combustion chamber of the mechanism. The impact action mechanism includes a hollow housing receiving therein a reciprocating impact member and a sleeve connected with the housing. The impact member has a tail portion receivable in the sleeve to define therewith, as the impact member moves into the sleeve, a closed combustion chamber. This combustion chamber communicates with the ambient atmosphere for exhaust of the combustion products and with a source of a combustible matter, respectively, through a pair of passages formed through the bottom of the sleeve. The impact action mechanism is small in size in the transverse section and offers a simple structure, which permits its utilization in the mining and construction industries, as well as for driving through holes in soil.