Abstract: A work vehicle control system includes an actual topography acquisition device, a storage device, a soil amount acquisition device, and a controller. The actual topography acquisition device acquires actual topography information, which indicates an actual topography of a work target. The storage device stores design topography information, which indicates a final design topography of the work target. The soil amount acquisition device generates a soil amount signal indicating a held soil amount of the work implement. The controller acquires the actual topography information from the actual topography acquisition device, the design topography information from the storage device, and the soil amount signal from the soil amount acquisition device. The controller determines an intermediate design topography positioned above the actual topography and below the final design topography in accordance with the held soil amount.

Abstract: A pivot coupling system that permits the use of attachable equipment such as material pushers or containment plows with a range of vehicles including all-terrain vehicles (ATVs), utility task vehicle (UTV), lawn and garden tractors, small farm tractors, small trucks, skid-steer loaders, etc.

Abstract: A working machine is disclosed. A boom supports an arm. An upper revolving body supports the boom. A lower traveling body mounts the upper revolving body in a rotatable state. A hydraulic actuator drives a hydraulic oil while relieving the hydraulic oil. A first pump supplies the hydraulic oil to the hydraulic actuator. A pump state detector detects load of the first pump. A controller reduces a flow rate of the hydraulic oil from the first pump to the hydraulic actuator when the pump state detector detects a predetermined state.

Abstract: An assist generator motor is driven by an engine to generate power or assists in a drive of the engine by supply of power from an electricity storage device. A revolving electric motor is driven by power supplied from the electricity storage device or supplies regeneration power generated by a regeneration operation to the electricity storage device. The assist generator motor is controlled by a first inverter. The revolving electric motor is controlled by a second inverter. The first inverter and the second inverter are mounted on a support bracket elastically supported on a revolving frame in a position different from a position where the electricity storage device is mounted.

Abstract: To rapidly stop an upperstructure even though relief pressure is lowered due to an abnormality in a hydraulic device included in a swing motor driving circuit while intending to stop the upperstructure when a predetermined delay time has passed since a swing operation tool is brought back to a neutral position, provided are: a first choke for controlling a parking brake to apply a braking force to a swing motor when a predetermined delay time has passed since the tool is brought back to a neutral position in a state where the tool is connected to a pilot pump; and an on-off valve and a second choke for controlling the parking brake to apply a braking force to the motor when a delay time shorter than the predetermined delay time has passed since the tool is brought back to the neutral position and disconnected from the pilot pump.

Abstract: A ditch digger for removing earth from the ground to dig a ditch, the ditch digger comprising: a body; a substantially elongated blade mounted to the body, the blade defining a blade front end and a substantially longitudinally opposed blade rear end, the blade defining a blade bottom section and a pair of laterally opposed blade side sections extending generally upwardly therefrom. When the ditch digger is in an operational configuration, the blade bottom section is lower adjacent the blade front end than adjacent the blade rear end. Moving the ditch digger along the ground with the blade front end inserted in the ground and the blade rear end provided above the ground removes the earth from the ground to dig the ditch.

Abstract: An oil storage tank includes a hydraulic oil tank configured to store hydraulic oil, a fuel oil tank configured to store fuel oil, a breather valve disposed on the hydraulic oil tank, and a breather hose connected to the breather valve. The hydraulic oil tank includes a first facing face facing the fuel oil tank. The fuel oil tank includes a second facing face facing the hydraulic oil tank. The second facing face has a fuel-oil-tank adjacent face and a fuel-oil-tank sloped face. The fuel-oil-tank adjacent face extends along the hydraulic oil tank. The fuel-oil-tank sloped face is connected to the fuel-oil-tank adjacent face and slopes relative to the fuel-oil-tank adjacent face so as to be away from the hydraulic oil tank. The breather hose is disposed along the fuel-oil-tank sloped face.

Abstract: A hydraulic system and method of controlling hydraulic pressure are disclosed. The hydraulic system includes a pump fluidly coupled to a reservoir that contains hydraulic fluid, a control valve fluidly coupled to the pump, the control valve being selectively movable between at least two positions, a relief valve fluidly coupled to the pump via a relief conduit, the relief valve operable to flow hydraulic fluid from an outlet of the pump to the reservoir, and a variable pressure setpoint module fluidly coupled to the relief valve and the control valve. The variable pressure setpoint module being operable to open the relief valve in response to at least two pressure setpoints depending on a position of the control valve.

Abstract: A working machine includes: a first electric motor used for work; a second electric motor used for applications other than work; a first inverter circuit connected to the first electric motor; a second inverter circuit connected to the second electric motor; a battery connected to the first and second inverter circuits; and a control unit that drives the first and second inverter circuits. The control unit has a discharge mode to discharge electric power stored in the battery, and discharges the battery by stopping the first inverter circuit while driving the second inverter circuit in order to make the second electric motor perform electric operation in the discharge mode. Accordingly, since the state of charge is reduced, the life of a capacitor can be increased.

Abstract: A control system and method operate to store target signals indicative of end of travel positions of components of a machine. The positions and velocities of the components of a machine are determined at least in part based upon signals received from sensors and command signals are generated to control movement of the components based upon input from an operator, proximate to the end of travel positions and the velocities of the components. Command signals are transmitted to control movement of the components. Multiple end of travel positions may also be defined.

Abstract: A simulation system for a machine is disclosed. The simulation system has a user interface configured to display a simulated environment, and a controller in communication with the user interface. The controller is configured to receive historical information related to performance of a machine, and recreate a past operation of the machine from the received historical information. The controller is also configured to provide to the user interface the recreated past operation for display in the simulated environment.

Abstract: A hydraulic system and earth-moving vehicle employing the hydraulic system are disclosed. The hydraulic system may include a first hydraulic cylinder and a second hydraulic cylinder, first and second hydraulic pumps and control valves to modulate provision of hydraulic fluid and pressure from the first and second hydraulic pumps to the first and second hydraulic cylinders as appropriate for the task being performed. If the task is digging with the earth moving vehicle, the first and second cylinders may be associated with tilting and lifting, respectively, and the control valves may be oriented so as to make each pump dedicated to one of the cylinders, and if demand is not being met, to then diminish power to the drivetrain to allow the tilting and lifting to be performed. The combiner may or may not be open during this time. If the task is not digging, a combiner valve can be opened to allow for cross-flow between the pumps and the cylinders.

Abstract: The loader bucket sieve apparatus is clamped between the jaws of the bucket of a bucket loader or the like, without tools or fasteners. Importantly, as the apparatus rests upon a given surface, the loader operator need only place the jaws of the bucket in the appropriate positions and then clamp the jaws together, reversing said procedure when wishing to disengage the apparatus. The apparatus may have straight supports or concave supports, depending upon need and bucket application. The sieves may extend beyond each side of the supports at each side of the apparatus in order to increase work surface beyond the bounds of the jaws. The sieves may be equidistantly spaced and may also be unequally spaced apart. Sieves may be disposed within all the holes or part of the holes of the supports.

Abstract: An attachment useful with a mobile platform is provided for containing and selectively pouring flowable materials. The attachment has an elongated spout extending outwardly and upwardly from a forward wall of the attachment. Rear and side splash guards may be provided to help contain flowable materials within the attachment. Side walls of the attachment may be angled from front to rear.

Abstract: An excavation control system for a machine is disclosed. The excavation control system may have a tool, at least one operator input device configured to provide manual control over movement of the tool, and a controller in communication with the at least one operator input device. The controller may be configured to receive an input related to an operator desired tool location, and determine that an operator is manually controlling movement of the tool toward the operator desired tool location. The controller may be further configured to automatically assume control over movement of the tool toward the operator desired tool location based on the determination.

Abstract: A soil removal apparatus in one embodiment has a motive power unit and an excavator joined to the motive power unit by a coupler, the excavator extending laterally of the motive power unit. The coupler includes a manipulator for manipulating the excavator to loosen and displace soil material in a path lateral to a path of movement of the motive power unit. The method relates to undercutting an object with a motive power unit, selectively halting and moving the motive power unit, and loosening and displacing soil lateral to the path of travel of the motive power unit.

Abstract: A connection for firmly securing an adapter for detachably carrying a replaceable digging tooth at its front end to a lip of an excavating container of excavating equipment. The adapter has an upper leg and a lower leg located proximate respective upper and lower surfaces of the lip. The connection has substantially aligned openings in the legs and the lip, and engagement sections of the adapter legs traverse the opening in the lip proximate and forward of an aft end thereof. A pressure applying unit, such as a hydraulic actuator, is arranged inside the opening and generates a generally horizontally acting force which draws the adapter and the lip towards each other. A stress member, which can be a C-clamp, is operatively coupled to the hydraulic actuator and resiliently deforms relative to its relaxed shape when it is subjected to the horizontally acting force.

Abstract: Soil is captured into a bowl attached to a frame of a scraper machine by maneuvering the machine while a cutting bit attached to the bowl slices through the underlying soil. The bowl is supported on the frame, and the soil cutting is accomplished via a spade bit attached to the bowl at a cut opening. The spade bit has a cutting edge with a forward protrusion flanked by swept back segments. A top surface of the spade bit may be contoured with a central ridge flanked by a twist contour surface to urge soil towards opposite sides of the bowl.

Abstract: A one-pass bucket includes a top wall, a bottom wall, a rear wall and a pair of side walls diverging forwardly from the rear wall to an open front end of the bucket, wherein the curved end walls extend convexly from the bottom wall to the top of the end wall at a forward edge thereof, and extending substantially diagonally upwardly from the bottom at a rearward edge so that the forward edge of the curved end wall curves upwardly towards the plane of the top wall so as to intersect the plane of the top wall non-tangentially and the rearward edge extends diagonally to intersect the plane of the top wall whereby a round bottom ditch is formed by rotating one of the curved end walls down and dragging that curved end wall through the soil longitudinally of the proposed ditch in a single pass.

Abstract: An arrangement for suspension of an operator cab on a machine frame in order to permit controlled motion of the cab relative to the frame is provided. The arrangement includes at least one first suspension member disposed between an underside of the cab and the frame for supporting the cab on the frame. The arrangement further includes at least one second suspension member disposed between a rear side of the cab and a rigid support structure and wherein the second suspension member is arranged at an elevated position relative to the underside of the cab. The second suspension member is adapted to provide an increased rigidity against cab movements both in the longitudinal and lateral direction of the machine during operation of the work machine.

Abstract: An apparatus for cleaning a culvert includes a rod pushing and pulling machine, a rod string made from a series of extension rods coupled end to end, which rod string is mounted at a proximal end to the rod pushing and pulling machine. A debris removal tool is mounted on a distal end of the rod string. The debris removal tool may comprises a rod having a center longitudinal axis, a proximal end, and a distal end, the rod having a coupling at its proximal end. A bucket is mounted at the distal end of the rod, which bucket has an end opening positioned so that movement of the bucket along the culvert scoops debris into the bucket.

Abstract: A tool for cleaning a drainage structure comprises a rod having a center longitudinal axis, a barrel housing having a proximal opening and a distal opening, the barrel housing having a center longitudinal axis and coupled coaxially to the rod, the barrel housing having an outside dimension that can be accommodated within the drainage structure, the distal opening of the barrel housing having a sinusoidal tearing contour. The tool further comprises a plurality of cutting implements radially coupled to and between the rod and the barrel housing, the cutting implements having a distal cutting edge and being angularly oriented to facilitate sweeping debris in a selected direction, and the barrel housing and cutting implements operable to rotate about the center longitudinal axis of the rod to dislodge and loosen debris inside the drainage structure.

Abstract: An attachment used in conjunction with a backhoe or track hoe to convert it into a machine to unload ties off of railroad cars. Two pins on an upper end of the attachment secure it to the distal end of the working arm of the backhoe or track hoe so that a front edge of the attachment point toward the backhoe or track hoe. Upper ends of four c-shaped members attached to an upper plate on the upper end of the attachment. Opposite lower ends of each of the four spaced apart c-shaped members are flattened on upper and lower surfaces into a point. A lower plate is secured to the upper surfaces of the lower ends of the c-shaped members to form the front edge. Support bars secure between adjacent c-shaped members and openings are provided in the c-shaped members to reduce weight while maintaining strength.

Abstract: A rear wheel drive assist for an articulated machine such as a wheel tractor scraper, the machine including a first frame section having a first longitudinal axis, a second frame section with a second longitudinal axis, the first and second frame sections being pivotally connected to an articulation hitch, and an articulation sensor configured to provide an articulation angle signal indicative of an articulation angle formed between the first and second longitudinal axes. The rear wheel drive assist includes a drive motor operatively connected to the rear wheel of the machine, and a controller configured to control operation of the rear wheel drive assist based upon the articulation angle signal.

Abstract: A multipurpose bucket for a front end loader is provided. The multipurpose bucket includes a second frame rotatably connected to a first frame to provide a pincer configuration and a scooping configuration. The first frame includes a bottom of the rear bucket wall; a pair of rear side walls with a plurality of pincer teeth; and a plurality of support arms extending from the rear bucket wall. The second frame includes a bucket floor having a pincer end and a scraper end; a pair of circular front side walls extending from the bucket floor to the pivot point, which increases the volume of the bucket and reduces spills; a plurality of pincer teeth extending from the pincer end of the front side walls; a rear plate extending from each of the pivots, attached to the front side walls, which forms the top of the rear bucket wall which increases the volume of the bucket; and a scraper blade extending from the scraper end of the bucket floor.

Abstract: A design for a wheel loader. The wheel loader has two units connected back to back via a pivot. Each unit has a base unit that is easily disassembled into parts no more than 8 feet wide for transport by using steel plates connected by sleeves, shafts and nuts. A dipper arm arrangement connects the base to a high capacity bucket arrangement of 300 cubic yards. Hydraulic cylinders raise and lower the bucket arrangement and tip the bucket arrangement for dumping. The hydraulic cylinders are operated by hydraulic pumps which are operated by diesel engines. A rotatable cab sits on top of the base to provide a view for an operator.

Abstract: The present invention relates to a system for the automatic movement of material in a working area comprising at least one movable piece of equipment, wherein the system has a control for the automatic movement of the piece of equipment with an automatic recognition of obstacles. In accordance with the invention, the control has a first obstacle processing function which moves an obstacle in the working area automatically using the movable piece of equipment; and/or in that the control has a second obstacle processing function which automatically removes an obstacle from the working area using the movable piece of equipment.

Abstract: An expandable implement attachment selectively connectable to a vehicle and having a frame assembly, a first bucket member laterally fixed to the frame assembly and a second bucket member laterally moveable relative to the frame assembly to provide a bucket with an adjustable width.

Abstract: A bucket has a pair of longitudinally parallel and spaced apart pins for attaching to a pin grabber quick coupler. The pins may require removal from the bucket for repair or replacement if the pins are damaged. One or more windows are formed in the side of the bucket for facilitating access to and the removal of the pins from the bucket.

Abstract: A one-pass bucket for digging a ditch by moving the bucket with its curved end down longitudinally of the proposed ditch, wherein the bucket includes a top wall, a bottom wall, a rear wall and a side wall diverging forwardly from the rear wall to an open front end of the bucket, the side wall being planar and defining a sharp acutely-angled corner with the bottom wall, the curved end wall, opposite the first side wall, extends convexly from the bottom wall to said top end at a forward edge thereof, and extending substantially diagonally upwardly therefrom at a rearward edge so that the forward edge of the curved end wall curves upwardly towards the plane of the top wall so as to intersect it non-tangentially and the rearward edge extends diagonally to intersect the plane of the top wall whereby a round bottom ditch is formed by rotating said curved end wall downwardly relative to the acutely angled corner and dragging the curved end wall through the soil longitudinally of the proposed ditch in a single pass.

Abstract: A loader excavator is described that is operable in an excavation mode or in a loader mode. The loader excavator comprises a main boom and a dipper boom, wherein a loader bucket or an excavator bucket can be selectively utilized in accordance with user preference.

Abstract: A variable width backhoe bucket having a width that is reversibly adjustable between a minimum value and a maximum value, comprising: a middle shell, flanking first and second side shells, and a constrained guidance system. The middle shell has a curved bottom, first and second opposite sides, and first and second opposite ends. Each side shell defines a bottom and a side panel such that the side shells are in substantially mirror symmetry with respect to each other. The constrained guidance system comprises a plurality of elongated male members, a plurality of complementary elongated female members, and a first and second oppositely opposed hydraulic cylinders each with one opposite end attached to the middle shell and the other end attached to one of the two side shells for moving the side shells in and out relative to the middle shell.

Abstract: An excavating tool for pivotal attachment about an axis to the outboard end of the dipperstick of an excavating system, the tool having multiple shanks offset longitudinally of the axis and offset radially about the axis. The tool does not have a bucket configuration. The shanks are arranged on the axis so the, as the tool is rotated about the axis, the shanks engage the substrate serially and axially offset.

Abstract: Aggregate mixtures such as dirt, sand, rock, concrete, etc. are separated into piles according to size by continuous agitation of the mixture and by gravitational and centrifugal forces exerted thereon. A container for the material, such as the bucket of a backhoe, has the bottom thereof at least partially open. An adjustable, hydraulically-driven rotating disk attaches to and covers the open portion of the bottom of the container, the combination having a gap, or a selected spaced-apart relationship, between the stationary container and the rotating disk. The mixture is agitated by the rotating disk and by contact with the other particles in the container. Particles smaller than the selected gap distance are thrown out through the gap between the disk and the open portion of the container by centrifugal force. Material larger than the selected gap size remains in the container.

Abstract: A mining shovel including a base and a frame rotatably mounted above the base. An upper member is fixed to the frame, and a lower member is fixed to said base. The lower member is engaged with the upper member to transfer horizontal forces between the upper and lower members, wherein the upper member is rotatably slidable relative to the lower member, and the lower member is axially slidable relative to the upper member. A bushing is interposed between said upper and lower members.

Abstract: A microwave imaging excavator for the detection, imaging and excavation of objects on or buried beneath the surface of the ground, such as metallic and dielectric land mines. A continuous wave stepped frequency ground penetrating radar signal is transmitted into the ground from a waveguide antenna mounted in one spade of a double spade auger. Direct breakthrough energy, signals reflected from the surface and the buried objects are received by an identical waveguide antenna mounted in the opposite spade. The spectra reflected from different buried objects become more distinct when the spectrum radiated spans the natural electromagnetic resonance of those objects. These signals are recorded as the twin-spaded auger is mechanically scanned over the ground in two mechanical rotational states of polarization. When the auger spades are on either side of a buried mine they are closed to grasp the mine which is then removed from the ground.

Abstract: An end-effector comprises a circulating scoop that cooperates with a plate that lies in its arcuate path. The plate spans the arcuate gap present within the scoop and preferably may be contained within that gap. The plate may be positioned to provide a bucket-like cavity facing in either fore or aft directions. The scoop and/or plate can carry indentations whereby they grasp shaped articles for controlled manipulation.

Abstract: A material handling vehicle is provided which includes a lower truck chassis and an upper material handling structure pivotally supported by the lower chassis, all functions of which vehicle are driven by a single engine. The material handling vehicle is controllable from a main truck cab on the truck chassis or from an upper operator's cab mounted on the upper structure. The single engine provides highway travel power and power to all excavator functions, while the vehicle, including remote travel and implement manipulation capabilities, may be controlled from the upper operator cab. The main engine, when used for over-the-highway travel, powers the driven wheels through a manual transmission in a conventional manner.

Abstract: The invention provides a method and an apparatus for controlling angles of a working machine, which even unskilled operators can easily and efficiently perform in excavation and loading operation.

Abstract: A manual dozer comprising a frame having a front and a rear and wheels for supporting the frame and allowing the frame to roll, The frame includes a handle extending upwardly from the frame for pushing pulling and steering the frame. A container is mounted on the frame, the container having a closed rear end and an open front end. A scoop is pivoted on the frame adjacent the front end thereof and extending in front of the open front end of the container. The scoop normally assumes a down position wherein a front edge of the scope is proximate the surface over which the manual dozer rolls. An arrangement is provided for pivoting the scoop from the down position to a raised position in which the front edge of the scoop tilts back toward the opening in the container to move scooped material into the container.

Abstract: A bucket for a front end loader is formed with a minimum number of parts so that it can easily be assembled held in fixtures and welded with robot welders. The bucket includes a unitary panel that forms a bottom wall and a rear wall, with a curved junction wall between the bottom and rear walls. An integral top rail is formed at the upper edge of the rear wall for structural integrity. The formed top rail is made with a sloped top rail wall to increase the visibility of a load in the bucket to an operator in a cab of a skid steer loader. The bucket walls and parts which weld thereon have locating tabs and mating edges for locating the parts automatically, so that they can be welded into position. The bucket is made with brackets for mounting it onto a quick attachment plate of a skid steer loader.

Abstract: A tiltable bucket assembly having a working edge on the leading end of the bucket and a forward extending extension arms, a pair of support arms, a pair of first wheels, a pair of second wheels, a pair of bucket-rotational members, a bucket-pivoting member, a bucket-linking arm, and a displacement body having an output shaft disposed therein. The support arms are connected at one end to each corresponding first wheel and extend forward from the corresponding first wheel. The extension arms are connected to the support arms at a point away from the first wheels. The bucket-rotational members are attached at one end to the bucket at a point away from the working edge. The other end of the bucket-rotational members are linked to the corresponding first wheels so that vertical displacement of the first wheels result in a substantially equivalent vertical displacement of the other end of the bucket-rotational members.

Abstract: Weight sensors coupled to the bed of a conventional haulage truck measure the weight applied to each tire strut as the truck is being loaded. Based on the weight applied to each strut, the exact position of the center of gravity of the load in the truck's bed is calculated and displayed on a monitor relative to a target position deemed optimal for uniform weight distribution. Based on this information, the operator of the loading machine can complete the loading operation in such a way as to shift the center of gravity toward the chosen target position. In another embodiment of the invention, an automated algorithm calculates and displays where the next bucket load should be dropped, based on its approximate weight, in order to shift the center of gravity toward the target location.

Abstract: An earth mover scraper combination having chain driven elevator drive sprockets for each of two chains which are mounted on plates that include pins extending into the frame of the elevator support. Two jacks are likewise inserted into the frame of the elevator support and can be used to force the pins away from the frame support thereby forcing the sprocket away from the frame support and tensioning the chain. Preferably, the jack is a hydraulic jack that can be operated with a simple grease gun. Metal shims are then placed between the mounting bracket and the frame assembly to maintain the chain tension.

Abstract: A hydraulic circuit system includes a shuttle block, and shuttle valves are arranged and connected within the shuttle block. The maximum pressure in a predetermined operation signal pressure group selected from operation signal pressures generated by pilot operating units is selected to produce a control signal pressure within the shuttle block. The control signal pressure is output to control devices such as a track communicating valve, a swing brake cylinder, and regulators for hydraulic pumps.

Abstract: A spill guard at the rear wall of the bucket of a loader is modified by providing a series of plates which are inclined to planes at right angles to the rear wall of the bucket at an angle of 45.degree. to the planes and to the plane of the rear wall of the bucket. The plates allow the driver to view through the spill guard between the plates. The spill guard plates however prevent any material including small particulate material from falling between the plates when the bucket is raised in view of the inclined angle of the plates.

Abstract: A circuit for generating an output signal used for driving a grounded load is provided. The circuit provides an output signal without glitches or spikes. The circuit also outputs a drive signal with enhanced responsiveness in transitioning from one output value level to another output value level. The circuit includes a plurality of control devices for providing respective output signals responsive to respective control signals. The base of a PNP transistor is coupled to the output of the control devices and acts as a buffer. The emitter of the PNP transistor is coupled to a voltage source and the collector is coupled to a grounded load for providing the drive current. Alternatively, an NPN transistor and current source provides the drive current to the grounded load. The circuitry may be used in an optical disk drive with the load and ground being a laser diode used for providing a laser beam in reading/writing an optical disk.

Abstract: A latch assembly for an excavator dipper of the invention includes a latch bar slot having a first opening, a second opening and a side wall. An annular projection protrudes from the latch bar slot side wall and has an upper surface and a side surface. A latch bar is slidably and removably mounted in the latch bar slot. The latch bar has a first portion, a second portion and a tapered portion located between the first and the second portion. The first portion has a larger cross-sectional area than the second portion. An upper retainer insert assembly is removably carried in the latch bar slot between the first opening and the annular projection.

Abstract: An excavator with a wireless controlled hopper-spreader allows a single operator to strip off topsoil and spread the stripped off soil more or less evenly after a mineable substance such as gravel is removed. The hopper-spreader uses about a fifty foot conveyor and may be totally operated by an operator in the excavator cab. This combination may be both faster and cheaper than a normal dragline operation.

Abstract: The invention relates to a hydraulically swung trenching shovel comprising a mounting part pivoted to the front end of an excavator shovel beam, on which mounting part the shovel may be pivoted by a hydraulic piston and cylinder unit around a pivot axis extending in the working direction, the piston and cylinder unit being arranged in a manner parallel to a cutting edge of the shovel in a carrying member provided in the upper edge region thereof and the mounting part is connected with a lever comprising a coupling rod for pivoting the shovel, said piston and cylinder unit being adapted to act on said lever. In accordance with the invention the coupling rod is directly pivotally connected on the piston and at the pivot point of the piston rod on the piston at least one rotary guide runner is rotatably mounted.