Abstract: A cylindrical, protective housing and accompanying insertion tool for shielding an in-ground sprinkler head. The cylindrical housing is inserted into the ground surrounding an in-ground sprinkler head, protecting the sprinkler head and subterranean feed lines from damage resulting from yard work or other traffic. The cylindrical housing prevents inadvertently sprinkler head collisions with lawn mowers, wheelbarrows, golf carts, or similarly wheeled vehicles. The insertion tool is a male-fitting press tool that provides vertical loads on the cylindrical housing upper extent to force it into soil surrounding a sprinkler head.

Abstract: A plurality of weight hammers (7,8) are provided, and each of the plurality of weight hammers has a shape for substantially evenly applying a hammering force with respect to a surface to be hammered of an object to be hammered (11), about a center line of the object to be hammered. Rotors (9, 10) for driving the weight hammers (7,8) are provided to the same rotating shaft (22) in such a positional relation that an engagement claw (9a) of one rotor (9) engages and drives one weight hammer (7), and, when engagement of the weight hammer (7) is released, an engagement claw (10a) of another rotor (10) in driving engages another weight hammer (8). The rotors are driven by the same driving means (26).

Abstract: The invention relates to a striking mechanism of a handheld electric power tool, in particular a percussion drill and/or percussion hammer, having a hammer cylinder, a piston mounted with a guide section inside the hammer cylinder in a longitudinally displaceable manner, and a piston outer guide on which a guide area of the piston is guided in a longitudinally displaceable manner. A piston end located outside the hammer cylinder comprises an overlap for overlapping an end area of the hammer cylinder, and the guide area at least partially belongs to the overlap or is affixed there.

Abstract: A plurality of weight hammers (7,8) are provided, and each of the plurality of weight hammers has a shape for substantially evenly applying a hammering force with respect to a surface to be hammered of an object to be hammered (11), about a center line of the object to be hammered. Rotors (9, 10) for driving the weight hammers (7,8) are provided to the same rotating shaft (22) in such a positional relation that an engagement claw (9a) of one rotor (9) engages and drives one weight hammer (7), and, when engagement of the weight hammer (7) is released, an engagement claw (10a) of another rotor (10) in driving engages another weight hammer (8). The rotors are driven by the same driving means (26).

Abstract: A hydraulic rotary percussive hammer drill includes a body containing a reciprocating percussion piston sliding under the effect of a main hydraulic supply circuit, this main circuit also being intended to cause the sliding of a roughly annular abutment piston housed in a cavity of the body, and having, on the one hand, a front face in contact with a shank and intended to place this shank a predetermined distance away from the percussion piston and, on the other hand, a rear face facing a rear wall of the cavity, characterized in that an external hydraulic supply circuit is able, when the main circuit is shut down, to introduce fluid under pressure between the rear face of the abutment piston and the rear wall of the cavity so as to maintain a space between these items.

Abstract: Self drilling anchors and related methods and apparatus. In one embodiment an apparatus comprises a drill bit, a hammer mechanism for hammering the drill bit in a first direction and in a second direction, and a selection mechanism for controlling whether, at a given point in time, the drill bit is hammered in the first or second direction.

Abstract: A device to transfer the alternately performed reciprocating movements of two pistons in a forward direction of a tool, the pistons being arranged coaxially about a center axis in a casing with the first piston running at least partly in a bore of the second piston and in sealing relation with the second piston bore. Another part of the first piston extends out of the path of movement of the second piston and is in sealing relation against the interior wall of the casing. The pistons are driven alternately to strike against an impact member common to both pistons which impact member is coaxial with the center axis and mechanically coupled to the tool.

Abstract: A ram for driving elongated objects into the ground including a piston jacket, an anvil disposed on the object to be driven, a mechanism located within the jacket for directly impacting with the anvil and for reciprocating at least substantially in a direction of driving the elongated object during driving operation wherein the mechanism for impacting further includes a plurality of cup springs arranged in series in the direction of driving the object and which are in contact with one another and wherein a lowermost cup spring directly impacts the anvil during driving operation.

Abstract: A powered impacting device including relativly movable concentric first and second pistons, the second piston providing a cylinder wall for guiding movement of the first piston. A spring is disposed between the pistons for exerting a biasing force maintaining the pistons in an initial relative position. A single impacting force is applied to the pistons, at first resulting in coincident movement thereof until the second piston drives an outer fastener component through workpieces to be fastened together, and then is stopped. The mass of the first piston is great enough to provide continued movement of the first piston, relative to the second piston against the bias of the spring, to drive an inner component of the fastener through the work to be assembled, deforming the outer component of the fastener so that the material pieces are held together.

Abstract: Disclosed is an apparatus for increasing the effectiveness of hammer-type pile drivers by making possible the use of higher hammer velocities without damaging the pile or the equipment. The apparatus includes a pair of aligned cylinders of unequal diameter, the smaller of which contains an anvil piston and the larger of which contains a driving piston, connected to a pile cap engageable with a pile. Means are provided for applying a deadweight load to the apparatus and for maintaining the space lying between the pistons full of liquid. In addition to enabling use of higher hammer velocities, the apparatus effectively incorporates the deadweight load into driving force when the hammer strikes.

Abstract: A rock drill has a housing accommodating pistons defining working chambers. Rotary drive of a drill steel has an overrunning clutch and a screw pair. The screw pair is arranged between the pistons and is formed by outer and inner helical threads respectively provided on these pistons. One of the pistons is kinematically connected with the housing, and the other piston which cooperates, during the drilling, with a chuck receiving the drill steel shank is in force transmitting connection with the rotary drive of the drill steel.The invention is aimed at lowering vibration of the rock drill housing by arranging the screw pair of the rotary drive between the pistons.

Abstract: A hydraulically actuated driving tool is provided with a ground engageable member which is driven into the ground by the action and reaction of a drive mass which is free to slide within the tool and which is repetitively forced away from and back to the ground engageable member in a manner determined by a hydraulic control system. Each repeated cycle of operation engenders two separate forces to drive the ground engageable member into the ground, one being the force exerted by high pressure fluid in the hydraulic control system when the drive mass is forced away from the ground engageable member and the other being the force exerted when the drive mass impacts back upon the ground engageable member. A switch means is provided whereby the returning drive mass initiates the next cycle of operation of the hydraulic control system.