Abstract: A double-head drilling machine is disclosed, which by changing over or converting small component units can cooperate with drill or drill pipes of different diameters. To this end, drive carriages (16) operating on drills or drill pipes, for example, comprise a carriage base element (32), to which a drive unit (42) is releasably fitted. The drive unit (42) can thus be replaced by a different drive unit having essentially the same geometry, which is designed for operating with a drill or drill pipe having a different diameter.

Abstract: For selective operation in a Diesel mode and a pressure air mode a Diesel type pile hammer is additionally equipped with a pressure air accumulator, which is connected to the working space of the cylinder by a servo valve.

Abstract: A drilling device comprises a drive motor (22), which sets a tool (36) in rotation, and a feed motor (14) which axially displaces the tool. Load sensors (12, 18, 20, 24) detect not only the tool feedrate (V) but also at least two of the three parameters, tool feed force (F), tool torque (M) and tool speed (U). An evaluation and control unit (70) evaluates the above-mentioned parameters and via control units (38, 42) activates the drive motor (22) and the feed motor (14) in such a way that the tool feed force (F) and the tool speed (U) or the tool torque (M) assume values at which the tool feedrate (V) for a specific ground hardness (H) is maximized.

Abstract: A boring tool with two driving heads which are used to sink a casing string and a borer string includes a controllable coupling mechanism fitted between the two driving heads. A mechanism is also provided for the lower driving head, such that the driving head is subjected to an additional downwards acting force. When both driving heads are coupled, the upper driving head is also subjected to an additional, downwards acting vertical force. In order to free the top end of the casing string, the coupling mechanism can be released so that the upper driving head can be fully raised, whilst the lower driving head remains in position adjacent to the ground.

Abstract: A drilling machine for a mobile drilling appliance which includes a housing which is adapted to travel along a jobber, a drive motor mounted on said housing, a pinion operatively connected to said drive motor, a step-down gear rotatably engaging said pinion, a driving socket located in the vicinity of a side face of said housing that contains a central opening which is adapted to receive a driving shaft that in turn is adapted to be connected to a drilling tool, and a driving ring positioned in said driving socket and engageable with said step-down gear.

Abstract: An apparatus for screwing a concrete pile (10) into ground comprises a rotary drive (26, 40, 42) and a linear drive (46, 48) both acting on the pile. An angle indicator (58) is associated to the rotary drive (26, 40, 42) and a linear position indicator cooperates with the linear drive (46, 48). A control unit (60) receives the output signals of the angle indicator (58) and the linear position indicator (56) and provides control signals to the rotary drive (26, 40, 42) and the linear drive (42, 48) corresponding to the pitch of the helical rib (16) formed on the concrete pile (10).

Abstract: In a hydraulic pile driver (10), the lifting cylinder (34) acting on the driving weight (12) has an attached position indicator (46, 50), which produces a signal corresponding to the momentary position of the piston rod (32) of the lifting cylinder (34). This signal is used for reversing a 4/3-valve, by which the two working chambers of the lifting cylinder can be connected to a pressure line or return line.

Abstract: A vibratory ram for ramming and/or drawing of ramming members, comprises at least two out-of-balance rotors, at least one motor and at least one transmission which drive the two out-of-balance rotors in synchronism in opposite directions, at least two unbalanced masses on each of said out-of-balance rotors, wherein each out-of-balance rotor has a first unbalanced mass disposed on a first shaft and a second unbalanced mass disposed on a second shaft, said first and second shafts being concentric and being rotatable about their common axis, and a phase adjusting device for altering the relative phase of the first and second shafts.

Abstract: A crank device for soil compacting apparatus having a crank shaft and a connecting rod coupled to each other by two eccentric elements rotatable about parallel shafts in which the first eccentric element is provided with a plurality of recesses and the second element is provided with a locking bolt with the elements being rotatable to relative positions at which recesses respectively are generally aligned with said bolt, with the bolt being mounted for movement between a first position at which it can enter a first recess generally aligned therewith and cannot enter a second recess generally aligned therewith and a second position at which it cannot enter the first recess aligned therewith and can enter the second recess aligned therewith.

Abstract: A material compacting vibration machine provided with an imbalanced system having coaxial first and second independently rotatable shafts carrying first and second drive elements and a pair of unbalanced masses having third and fourth drive elements secured thereto with driving connections between the first and third drive elements and between the second and fourth drive elements, and a drive shaft selectively coupled to the first and second drive elements, wherein the four drive elements all are disposed on one side of the imbalanced system and are shielded by a cover.