Abstract: A working machine includes an auxiliary system carried by the working machine, one or more batteries and an onboard thermal transfer system. The one or more batteries power an electrical system of the working machine. The onboard thermal transfer system utilizes a coolant configured to remove at least a portion of heat generated by the one or more batteries during charging or discharging of the one or more batteries and using the coolant heated by the thermal transfer system to heat the auxiliary system.

Abstract: The present disclosure relates generally to systems and methods for sensing wear in machines designed to reduce or break-down material. More particularly, the present disclosure relates to systems and methods for sensing wear of reducing elements used by excavation machines such as surface excavation machines. The present disclosure relates to a wear sensing system including a multi-level wear sensor protection system. The multi-level wear sensor protection system includes a first level of protection, a second level of protection, and a third level of protection.

Abstract: A cutting bit retaining assembly for mounting a cutting bit at a cutting machine includes a holder body having a through bore to receive a bit shaft. A retainer acts against the holder body and bit shaft and includes a first and second abutment member that provides a reliable and constant locking force between the body and the shaft.

Abstract: The invention relates to a method for sinking or introducing cavities in rock, wherein the face of the cavity (2) is melted using electrical plasma generators. In order in such a method to produce an energy density at the face of the cavity (2), the energy density being sufficient to completely or partially evaporate the in-situ stone, the invention proposes arranging a heat shield (4) immediately over the face of the cavity (2), the heat shield (4) forming with the face of the cavity (2) a dynamic pressure space (7) in which a temperature of more than 2000° C. is established at a pressure of more than 2 bar by heating with plasma generators (8). This supply of energy is sufficient to melt the stone in-situ at the face of the cavity (2), to completely or partially gasify it and to remove it from the cavity (2).

Abstract: A method of designing a cutting drum for earth moving equipment is disclosed. The cutting drum has two or more ring segments, each ring segment comprising a plurality of cutting tools, and the rotational position of at least one ring segment is adjustable relative to one or more other ring segment and fixable in the new rotational position. The method involves inputting a plurality of design parameters of a cutting drum into a computer program, performing a computer simulated analysis of the cutting drum using the computer program to determine at least one operational value associated with at least one design objective, using the computer simulated analysis to determine the relative locations of the ring segments that correspond to the at least one design objective, and rotating the or each adjustable ring segment relative to at least one other ring segment so that the relative locations of the ring segments correspond to the at least one design objective.

Abstract: The present invention pertains to a tunnel excavation device, which includes an excavation head, a main body on which the excavation head is rotatably mounted, a motor provided in the main body and rotates the excavation head, and a controller for controlling the motor, wherein the excavation head includes a perforating means formed by maintaining a predetermined interval from the center of a body part, which has a front surface formed in the shape of a circular plate, to the outer surface of the body part, an injection means for injecting water and liquid nitrogen into the hole formed by the perforating means, and a plurality of cutters provided on the surface of the main body for crushing the bedrock. According to the present invention, the perforating means such as a laser drill or the like forms a hole and water and liquid nitrogen are injected into the hole so as to crush the bedrock when the excavation work is carried out.

Abstract: A boom is made of telescoping boom sections. A movable cutting nozzle is on the boom and sprays water. In one embodiment, the boom is coupled to the climber section of a platform that climbs a tower. A further beam is mounted on the other side of the hydraulic elevating platform and carries a movable power pack/counterweight. In a second embodiment of the present invention, the device is oriented horizontally and the platform moves horizontally on a rail. In this configuration, the elongated boom has a distal end protruding over the top edge of a dam or other structure. Depending vertically from the boom is another vertical boom carrying the cutting nozzle. This boom travels on the outer boom section of the elongated boom and extends downwardly a distance to allow the device to treat the concrete surface downward from the top edge of the structure.

Abstract: The subject matter of the invention disclosed herein is a hydro-demolition device and a top-down method for deconstructing structural surfaces. The device includes a rigid support frame mounted above a work-face on the structural surface being deconstructed. The rigid frame supports a cutting nozzles that move up and down along the structural surface. The nozzles may be mounted on a carriage that is movably connected to the rigid frame. The carriage may swing about a swing axis so that the nozzles move axially toward and away from the carriage. The nozzles may be movable toward and away from the work-face. The various movements of the nozzles are effectuated by rotators and drivers.

Abstract: A mining apparatus includes two tool drums, which are arranged rotatably side by side in twin arrangement on a drum carrier and which are respectively provided with a plurality of tool carriers which support cutting tools arranged over the periphery of the tool drums and which can be rotatingly driven and the shaft axes of which run substantially transversely to the drum axle. The shaft axes of the tool carriers of the first tool drum span a first conical surface about the drum axis and the shaft axes of the tool carriers of the second tool drum span a second conical surface about the drum axis, where the conical surfaces are open to opposite sides and are preferably oriented such that they are mutually inclined in an O-arrangement.

Abstract: There are provided high power laser and laser mechanical earth removing equipment, and operations using laser cutting tools having stand off distances. These equipment provide high power laser beams, greater than 1 kW to cut and volumetrically remove targeted materials and to remove laser affected material with gravity assistance, mechanical cutters, fluid jets, scrapers and wheels. There is also provided a method of using this equipment in mining, road resurfacing and other earth removing or working activities.

Abstract: A rotary cutter drum for a continuous mining machine having a cutter drum, a bearing hub, an inner bearing, a sealing assembly and a shaft disposed in an inner portion of the cutter drum, the shaft having at least one flat passageway disposed along a longitudinal axis of the hub for allowing a lubricating fluid to move from an oil reservoir to a bearing surface.

Abstract: A pair of semi-cylindrical segments adapted to be connected to form a center drum of a cutter head of a mining machine. The split line between the semi-cylindrical segments is not continuous, but lies on more than one plane.

Abstract: The mining vehicle for spraying a fluid including a vehicle portion having a propulsion system for propelling the mining vehicle, a boom connected to the vehicle portion, and a hydraulically driven pivot assembly connecting the boom to the vehicle portion. The pivot assembly includes a horizontal axis pivot member to allow the boom to pivot about the vehicle portion about a first horizontal axis. The boom comprises at least three boom arms and a nozzle on an end thereof, with each of the boom arms being pivotable about an adjacent one of the boom arms about a second axis. The second axis is substantially perpendicular to the first horizontal axis.

Abstract: A bore hole tool 10 for removing minerals from the earth. The tool has a case 11 having a nose 12. The case contains a drilling sub-system A, a mining sub-system B, and a pumping sub-system C. The drilling sub-system ablates material in front of the nose providing a space into which the tool can be advanced. The mining sub-system breaks down mineral resources and creates a slurry around the tool. The pumping sub-system pumps the slurry created by the mining sub-system away from the case. A method of removing minerals involves providing a bore hole tool 10, ablating material in front of the nose 12 of the case to provide a space into which the tool can be advanced, breaking down mineral resources and creating a slurry around the tool, and pumping the slurry created by the mining sub-system away from the case.

Abstract: A hyper-pressure water cannon, or pulse excavator, is able to discharge fluid pulses at extremely high velocities to fracture a rock face in excavation applications. A compressed water cannon can be used to generate hyper-pressure pulses by discharging the pulse into a straight nozzle section which leads to a convergent tapered nozzle. The hyper-pressure water cannon design is relatively compact, and the pulse generator can readily be maneuvered to cover the face of an excavation as part of a mobile mining system.

Abstract: A system for forming an oil sand slurry from mined oil sand is provided, comprising a slurry preparation tower having an intake opening through which oil sand enters the slurry preparation tower, a first sizer device to comminute the oil sand passing through it, a second sizer device to further comminute the oil sand, and a pump box for receiving oil sand that has passed through the second sizer and feeding it to a pump; at least one conveyor, having a discharge end, for transporting mined oil sand to the slurry preparation tower; a metal detector for detecting a piece of metal in the mined oil sand and transmitting a signal; and a metal rejection device operative to, in response to the signal from the metal detector, reject a portion of oil sand containing the piece of metal before the portion of oil sand enters the slurry preparation tower.

Abstract: A degradation assembly, comprising a platform comprising a surface. A plurality of picks each comprising a hard tip and a shank may be mounted on the surface. A plurality of sensors may also be disposed within the platform such that they can measure impacts on at least one of the picks. The sensors may be in communication with a processor. The degradation assembly may be capable of detecting and determining the location of a selected pick measuring impacts on at least one pick with at least one sensor, detecting a variation on the at least one pick with the at least one sensor, and determining a location of the at least one pick with more than one of the sensors.

Abstract: A tunnel excavation technique using a water jet. A water jet system includes a moving unit movable back and forth with respect to an area to be blasted for tunnel excavation, an articulated robot arm mounted on the moving unit, a water jet nozzle which ejects high-pressure water and an abrasive toward an area to be excavated, and a control unit which controls the moving unit, the articulated robot arm and the water jet nozzle. A free face having a predetermined depth is formed of the area to be excavated in the direction in which the tunnel is to be excavated using the water jet system. Since the blasting is performed after the free face is formed, blast vibration can be effectively restricted.

Abstract: A cutting bit includes a tool pick having a head and a shank, and a cutting tip having a body, a cap extending frontwardly from the body, and a base extending rearwardly from the body. The base defines an outer diameter of the cutting tip and a substantially flat rear surface at the rear of the cutting tip. A post extends axially frontwardly from a front surface of the head of the tool pick. A cavity extends axially frontwardly into the base from the rear surface of the cutting tip, the cavity having a diameter equal to or less than about 40% of the outer diameter of the cutting tip. When the cutting tip is mounted to the tool pick, the post is received into the cavity and a portion of the front surface of the tool pick mates with a portion of the rear surface of the cutting tip.

Abstract: A pulsed water-jet apparatus comprising a high pressure water pump delivering water to a nozzle and a means of interruption disposed at or near the nozzle periodically interrupting the flow of water passing through the nozzle thereby generating a pulsed water-jet. An accumulator is disposed between the pump and the nozzle, wherein the accumulator is a high pressure accumulator storing energy between pulses of the pulsed water jet and the pressure drop at the accumulator inlet due to the release of each pulse of the pulsed water jet is less than twenty percent.

Abstract: Methods and systems for automatically operating a continuous mining machine. One method includes accessing at least one coordinate of a cutting face stored in a computer-readable medium, automatically operating a first actuator to position a platform a predetermined clearance distance from the at least one coordinate, the platform supporting a cutterhead, and automatically operating a second actuator to position an arm at a tramming position after positioning the platform the predetermined clearance distance from the at least one coordinate, the arm coupled to the platform and including the cutterhead.

Abstract: Methods and systems for automatically operating a continuous mining machine. One method includes performing an automated cutting operation without requiring manual interaction using a cutterhead included in an arm pivotably coupled to a movable platform and stopping the automated cutting operation without requiring manual interaction. Stopping the cutting operation includes (i) stopping at least one motor driving the cutterhead, (ii) operating a first actuator to retract the platform from a cutting face by a predetermined distance, and (iii) operating a second actuator to swing the arm to a predetermined tramming position.

Abstract: Methods and systems for automatically operating a continuous mining machine. One method includes accessing at least one coordinate of a cutting face stored in a computer-readable medium, automatically operating at least one actuator to position a platform a predetermined starting distance from the at least one coordinate, the platform supporting a cutterhead, and automatically operating the at least one actuator to advance the platform toward the cutting face and beyond the at least one coordinate by a predetermined depth-of-cut to perform a cut of the cutting face with the cutterhead.

Abstract: The invention relates to a mining vehicle and method for its energy supply. The mining vehicle has a carriage, driving equipment for moving the carriage, and at least one mining work device. Further, the mining vehicle has at least one electric motor for operating a main function of the mining vehicle, and at least one electric motor for operating an auxiliary function of the mining vehicle. The mining vehicle further has a power-generating auxiliary unit. When necessary, the power-generating auxiliary unit supplies at least part of the power required by the electric motor operating the auxiliary function.

Abstract: A core breaker positioned between cutting drums on a mining machine that includes a generally circular support member, and a beveled blade portion on the radial outward surface of the support member. The beveled blade portion includes a plurality of wedge-shaped portions and a plurality of serrated portions. Each wedge-shaped portion is connected to an adjacent wedge-shaped portion through a mediate serrated portion. Both the wedge-shaped portions and the serrated portions are generally beveled. The wedge-shaped portions and serrated portions maintain curvatures, giving the blade portion a generally undulated appearance. The blade portion has two faces, and can be beveled on a single face. Alternatively, the blade portion can be beveled on each face. The beveled surfaces can be substantially symmetrical or asymmetrical from a view in the radial direction of the generally circular support member.

Abstract: A holder block assembly for a drum-type cutting tool has a holder block, a sleeve, and a piston carried in a piston channel formed in the holder block. The sleeve includes a shank and an enlarged flange at an end of the shank. The sleeve shank is received in a hole in the holder block, with the shank and hole wall forming a number of axially spaced interference fits. A source of pressurized fluid applied to the holder block forces the piston against the sleeve to extract the sleeve from the holder block. Sealing structure between the piston and the holder block prevents the release of hydraulic fluid when the sleeve is released.

Abstract: The machinery system and its application herewith, intended to create an opening in the roof of a Reactor Primary Containment of Generation II and III Nuclear Power Electric Generating Station. This opening is necessary to replace an aging nuclear reactor with a new, safer and more efficient reactor. Generation II and III Nuclear Power Electric Generating Stations include General Electric (GE) Boiling Water Reactor BWR/2, 3, 4, 5 and BWR/6 located in Mark II, and Mark III wet containments and Pressurized Water Reactors manufactured by Westinghouse, Combustion Engineering and Babcock and Wilcox located in dry containments. Until this time, existing reactor replacement was not possible due to Reactor Primary Containment structural enclosure configuration. The Dual Head Vertical Milling Machine System will remove a Reactor Primary Containment Dome Segment thus providing an opening, allowing reactor replacement and the electric generating station to remain operational for an other 40 years and beyond.

Abstract: In a heading machine (1) including a track chain running gear, a cutter arm (3) pivotally fixed to a machine frame and comprising rotatably drivable cutting tools (4), a fresh-air supply for supplying fresh air to the working face, and an exhaust means for evacuating exhaust air and dust from the working face, the heading machine (1) further comprises at least one anchor drilling and setting device (5) disposed behind the cutting tools (4) and at least one working platform (11) disposed at least partially laterally outside the anchor drilling and setting device (5), wherein at least one air duct of the fresh-air supply and/or the exhaust means is led through below the at least one working platform (11) and/or laterally led around the working platform (11).

Abstract: A tool pick including a head portion, a larger diameter shoulder positioned rearwardly adjacent to the head portion and joined to the head portion at a junction, and a shank extending rearwardly with respect to the shoulder. Two or more fins extend generally radially outward from the head portion and the shoulder, each fin having an outer surface sloping outwardly and rearwardly from the head portion and a pair of side surfaces, a rear end of each fin being located rearward of the junction between the head portion and the shoulder, the fins defining a maximum diameter of at least about 105% of the diameter of the shoulder such that the outer surface of the fin at an axial position aligned with the junction is located radially outward with respect to the junction.

Abstract: A cutting bit includes a tool pick having a head and a shank, and a cutting tip having a body, a cap extending frontwardly from the body, and a base extending rearwardly from the body. The base defines an outer diameter of the cutting tip and a substantially flat rear surface at the rear of the cutting tip. A post extends axially frontwardly from a front surface of the head of the tool pick. A cavity extends axially frontwardly into the base from the rear surface of the cutting tip, the cavity having a diameter equal to or less than about 40% of the outer diameter of the cutting tip. When the cutting tip is mounted to the tool pick, the post is received into the cavity and a portion of the front surface of the tool pick mates with a portion of the rear surface of the cutting tip.

Abstract: In a cutting tool for a mining machine, in particular shearer, including a tool base body and a cutting insert (1) made of a diamond composite material and fixed in a receiving bore (6) of the tool base body, the diameters of the cutting insert (1) and the receiving bore (6) are dimensioned such that the cutting insert (1) is held in the receiving bore (6) by a shrink-press fit.

Abstract: A tool used for cutting coke or other hard materials in drums, adapted for being mounted to a boring rod with which the water can be run under pressure into the tool thus that, the water can be run toward the boring and cutting nozzles, being provided with a valve mechanism that can rotate about a coupling angle for releasing and closing the flow channel ports depending on a control input, with a first coupling position of the valve mechanism for boring and another coupling position for cutting, whereby the valve mechanism can be coupled at a water pressure reduced to the coupling pressure by rotating about the coupling angle, is simplified as to construction and handling in that the valve mechanism comprises a valve body in the water intake area of the casing, which has a cylindrical shape and a section for the water flowing inside the casing, as well as being rotationally mounted and having the possibility to be lifted and lowered in a cylindrical section of the inner wall of the casing, the valve body bein

Abstract: An assembly is disclosed including a holder block, a cutting pick, and an optional hollow sleeve, wherein the shank of the cutting pick is inserted into the holder block or, where present, into the hollow sleeve. When assembled, surfaces of the components meet at an interface. At least one of the first interface and the second interface includes one or more sets of wear elements including cemented carbide bodies press fit into recesses in the forwardly oriented surfaces meeting at the interfaces. The wear elements mitigate direct contact between the opposing surfaces of the components at the interfaces and prevents excessive wear from repetitive impact because the harder wear elements, e.g., cemented carbide, are contact points between the opposing surfaces of the components at the interfaces. A machine incorporating the assembly and a method of manufacturing the assembly are also disclosed, particularly a machine for mining, excavating, tunneling, road planing and/or construction.

Abstract: A block and sleeve assembly and a sleeve per se are disclosed. The sleeve has a central bore with a rearwardly opening taper. The holder block has a side-to-side opening with a bridge. An angle of the rearwardly opening taper and/or the distance from the beginning of the taper of the central bore of the sleeve to the surface of the side-to-side opening are sized to allow rearward removal of a shank of a sheared cutting pick from the sleeve. Optionally, an outer circumferential surface of at least a portion of the sleeve shank is forwardly tapered and the opening in the holder block is complementarily tapered to receive the sleeve shank. A rearward biasing retainer clip can also optionally be included.

Abstract: A tool pick assembly and a tool and block assembly are disclosed. A sleeve is positioned about the shank to allow rotation of the tool pick and also friction fit with the block. The sleeve is stepped in complement to the shape of the surface of the shank of the tool pick and the shape of the surface of the bore in the tool holder and extends substantially all of the length, optionally all of the length, of the stepped bore in the block to reduce or prevent dust and fines from entering and wearing the bore surface. When assembled, the stepped sleeve and complementarily shaped shank of the tool pick each do not extend past the rear surface of the bore to mitigate or prevent shank deformation from impact during use.

Abstract: In a heading or extraction machine (1) including extraction tools that are movable over the working face, and track walling devices such as anchor drilling and setting devices (9), the machine (1) comprises a platform (6) that is displaceable in the longitudinal direction of the machine and carries at least two track walling devices each mounted to be separately displaceable relative to the platform (6).

Abstract: An apparatus for mining a mineral seam, comprising a motor, and a cutting drum carried on the frame for winning aggregate material from the mineral seam. The cutting drum encloses the motor, and a gear case drivingly connected between the motor and the cutting drum transmits power from the motor to the cutting drum. The gear case is also enclosed within the cutting drum.

Abstract: A block and sleeve assembly is disclosed including a holder block, and a hollow sleeve. In radial cross-section, outer peripheral edges of the shoulder portion of the sleeve have a shape of a first polygon. The holder block and the hollow sleeve include cooperating rotation inhibiting features. For example, the holder block includes a stop projecting forwardly past a plane of the front face and positioned radially offset from a circumference of the opening in the holder block to allow a rearward surface of the shoulder portion of the sleeve to contact the front face of the holder block and to prevent rotation of the hollow sleeve greater than N degrees, N = 360 n , where n is the number of sides of the first polygon, by contacting an outer peripheral edge of the shoulder portion with the stop. A sleeve per se and an assembly including a cutting pick are also disclosed.

Abstract: The present invention provides a drive for a grinding or cutting machine. The drive comprises a body having a drive coupling for receiving at least one drive shaft in a manner so that the or each drive shaft is drivable by the drive. The drive also comprises a mount for mounting the body to a portion of the machine such as to a linkage arm of an earth grinding or cutting vehicle. The drive coupling is arranged to inter-fit with a portion of the or each drive shaft.

Abstract: The present invention relates to a novel method of mining underground coal and recovering coal seam gas, the method including locating a seam of coal; digging a mine shaft to reach the seam of coal; constructing a ventilated underground control center which includes a computerized control panel, wherein the computerized control panel controls the movement of a drill head, a hollow drill shaft, a movable hydraulic shield, a movable resin roof bolting machine, and a movable waste extrusion device; providing mining personnel to the ventilated underground control center; and allowing the mining personnel to operate the computerized control panel wherein they perform the tasks of moving the drill head into the seam of coal to obtain aggregate coal and coal seam gas; extruding waste material into mined-out space of the coal seam; and transferring the aggregate coal and coal seam gas to the surface of the earth.

Abstract: A pair of semi-cylindrical segments adapted to be connected to form a center drum of a cutter head of a mining machine. The split line between the semi-cylindrical segments is not continuous, but lies on more than one plane.

Abstract: A continuous mining machine in which the machine is capable of mining a width exceeding the width of the machine chassis by articulating the cutter end of the machine relative to the rear of the machine.

Abstract: A non-rotating mining cutter pick has a shank portion with a non-circular cross-section, a head portion including a tip region distal from the shank portion, a shoulder portion separating the shank portion from the head portion, and a cutting insert mounted at a front end of the tip region. The cutting insert includes a body formed of tungsten carbide and an element formed of a superhard material, such as PCD or other material having a prescribed knoop hardness. At least a portion of a first surface of the element is exposed on a cutting surface of the cutting insert, which improves wear properties of the mining cutter pick. The element is fused to the body of the cutting insert, preferably in a high pressure-high temperature (HPHT) process. A method of manufacture and a cutting machine incorporating the non-rotating mining cutter pick on the rotatable element are also disclosed.

Abstract: A continuous mining method includes operating a vibratory milling machine having a milling head, a base, and a milling tool to oscillate the milling head in a substantially linear reciprocating fashion relative to the base to move the milling tool along a milling axis; and advancing the vibratory milling machine in a work piece in a cutting direction and wherein milling axis is oriented at an attack angle relative to the cutting direction, the attack angle being between about 0 and about 40 degrees.

Abstract: A cutting bit includes a body having a head and a shank, a cutting tip attached to a front surface of the head, the cutting tip including a base portion, an upper portion and a tip portion, and a cavity extending into an interior of the cutting tip a distance from a bottom surface of the base portion. The distance the cavity extends into the interior is such that a bottom of the cavity is axially closer to the tip portion than at least a portion of a skirt separating the base portion and the upper portion. The cutting tip is attached by both a mechanical connection and a joining process. An example of a mechanical connection is a post on the front surface of the head of the body inserted into the cavity of the cutting tip. A cutting tip per se, a cutting bit on a mining machine and a method of manufacturing of a cutting bit are also disclosed.

Abstract: A process for increasing resistance to the flow of gas in underground mining operations includes providing a foam composition at desired selected locations to create a barrier to the flow of gas.

Abstract: An apparatus for degrading a paved surface includes two or more pavement degradation tools, each rotating about an axis. The pavement degradation tools are adapted to degrade a paved surface substantially normal to their axes of rotation. A linking mechanism links the rotation of the pavement degradation tools such that rotation of one causes the rotation of the other. In selected embodiments, this linking mechanism includes gears operably connected to the pavement degradation tools that rotate with the pavement degradation tool about their axes of rotation. These gears directly engage one another causing the gears, and their corresponding pavement degradation tools, to rotate in opposite directions.

Abstract: A method for detaching a manhole frame (7) that is embedded in a road surface, wherein the manhole frame (7) is cut horizontally starting from the inside, without significant exposure of the outside area surrounding the manhole frame (7), by using a horizontally oriented rotating cutting blade (15) that performs eccentric circumferential runs along the inside of the manhole frame.

Abstract: A method and apparatus for cutting a borehole substantially in the shape of a bread loaf within a mine includes four cutting systems. The first cutting system is a pair of three-armed, counter rotating, cutting heads which remove material from the mine face in a substantially vertical plane. The second cutting system is a pair of rotating cutting drums which follow the pair of counter rotating cutting heads. The third cutting system is a substantially vertical, rotating cutting head which removes the kerf formed at the ceiling or roof portion of the borehole. The fourth cutting system is a plow which both removes the kerf at the bottom of the borehole and directs the mined material to a conveyor system to remove the mined material from the mine.

Abstract: A protective shield for machines having an operator station protects an operator located on the operator station during operation of the machine. The protective shield defines a flexible curtain of elongated members which covers an exposed side of the operator station, but yet is also of a construction that allows the operator to reach and see through the curtain when desired. The protective shield has an adjustable height to accommodate a variety of machines and to adjust to underground mines having different sizes and shapes. The protective shield is easily removable from and reattachable to machines without the use of additional tools, thereby enhancing its versatility and usefulness. In a preferred embodiment, the protective shield comprises a somewhat stretchable chain mesh, which hangs from a roof canopy extending along side the operator station.