Abstract: A paving machine employs an electrically heated screed assembly to uniformly heat a screed plate of the machine. Uniform heating is achieved by inserting a thermally conductive plate between electrical heating elements and the screed plate. An insulation layer may be provided above the heating elements to direct the heat downward into the thermally conductive plate. The heat spreads relatively uniformly throughout the thermally conductive plate, thereby uniformly heating the screed plate. A clamping mechanism is also provided that, when tightened, provides a compressive force, thereby holding the assembly in place. When released, the pressure is alleviated, thus permitting a heating element to be removed for repair or replacement without the need to remove the screed plate.

Abstract: A fold linkage is provided that is usable in combination with a conveyor assembly having a foldable conveyor section and a main conveyor section. The fold linkage includes linkage members and hinge sections that are rotatably attached to each other and that are connectable to the conveyor sections without interference with the conveyor assembly truss members. The fold linkage further includes a pressure operated cylinder that is extendable and retractable so as to fold and unfold the conveyor assembly.

Abstract: A method and an apparatus are disclosed for cutting rumble strips in the surface of a roadway. The apparatus is a self-propelled machine which includes a frame and a drive mechanism mounted to the frame and adapted for advancing the machine across the surface of the roadway. The machine also includes a generally cylindrical cutting drum that is mounted on the frame for rotation about an axis that is disposed generally parallel to the surface of the roadway. A plurality of cutting teeth are mounted on the outer surface of the drum in a predetermined pattern, and a mechanism is provided for rotating the cutting drum about its axis. The drum is maintained at a predetermined position with respect to the surface of the roadway so that the cutting teeth will cut into said surface a relatively constant, predetermined depth as the drum is rotated about its axis while the machine is advanced along the surface of the roadway.

Abstract: An apparatus for making asphalt paving material includes a dust collection and distribution system by which aggregate dust that is collected during the heating and drying of aggregate may be introduced into the mixing chamber and distributed over a substantial portion of the area of the mixing chamber. By distributing the aggregate dust over a broader area of the mixing chamber than has been previously known, the mixing effort required to achieve a thorough blending of the dust into the mixture is reduced, and the quality of the asphalt paving composition is improved.

Abstract: A rock crusher such as a cone or jaw crusher incorporates hardened tapered inserts in the manganese or other wear liner of at least one of its crushing elements. The inserts extend outwardly from the crushing surface of the crushing element towards the facing crushing surface so as, in use, to act as pick axes that shatter rock primarily by impact rather than pulverizing the rock by compression. The inserts are fixed in a heat treated manganese wear liner either by bonding or by press-fitting. The inserts substantially improve the life of the wear liner and, unexpectedly, 1) produce product of a highly uniform gradation in the desired ranges, 2) consistently produce product with a very high cubicity, 3) dramatically reduce the crusher's power requirements, and 4) significantly increase the crusher's capacity.

Abstract: A grizzly screen apparatus has a screen of grizzly bars having first ends mounted in a transverse end member and second ends placed in a slotted comb member having alternating shallow and deep bed slots. The screen is rotatable about a transverse axis whereby the second ends of secondary grizzly bars in the deep bed slots are lowered relative to the second ends of grizzly bars in the shallow bed slots, resulting in simultaneous steepening of the screen and an increase of the interbar distance, to remove obstructing oversize objects from the screen. Each grizzly bar has a transverse lock bar at the first end which retains the grizzly bar within an aperture in the transverse end member without bolts or other fasteners. Obstructions on the grizzly screen may be cleared without the use of manually operated tools, and if desired, may be cleared by remote control.

Abstract: A milling machine is disclosed, which machine includes a frame, a drive mechanism for advancing the machine across a surface to be milled, and a milling assembly mounted on the frame of the machine for cutting a width of material from the surface in the path of the machine. The milling assembly includes a generally cylindrical milling drum having a plurality of cutting teeth, which drum is mounted for rotation about its axis. The milling assembly also includes a vibratory assembly which is mounted so as to impart vibration to the milling drum. The vibratory assembly includes an elongate shaft, a drive mechanism for rotating the shaft, and an eccentric weight that is mounted on the shaft. The eccentric weight has a non-symmetrical distribution of mass about the shaft so that vibration will be created upon rotation thereof. Also provided is a vibration isolator for isolating the vibratory assembly so as to limit the transmission of vibration created thereby to the frame of the machine.

Abstract: A rock crusher such as a cone or jaw crusher incorporates hardened tapered inserts in the manganese or other wear liner of at least one of its crushing elements. The inserts extend outwardly from the crushing surface of the crushing element towards the facing crushing surface so as, in use, to act as pick axes that shatter rock primarily by impact rather than pulverizing the rock by compression. The inserts are fixed in a heat treated manganese wear liner either by bonding or by press-fitting. The inserts substantially improve the life of the wear liner and, unexpectedly, 1) produce product of a highly uniform gradation in the desired ranges, 2) consistently produce product with a very high cubicity, 3) dramatically reduce the crusher's power requirements, and 4) significantly increase the crusher's capacity.

Abstract: A gyratory crusher includes an anti-spin mechanism which is coupled to a lower end of a main shaft of the crusher and which prevents the main shaft and associated crushing head from spinning when the crusher is not subject to a crushing load. The anti-spin mechanism includes 1) a hydraulic brake, and 2) a gear train which couples the main shaft to the hydraulic brake so as to drive the hydraulic brake to rotate faster than the main shaft while at the same time permitting relative sliding motion between the main shaft and the hydraulic brake without unduly increasing the complexity or height of the crusher. The hydraulic brake is supercharged so as to respond immediately to a tendency of the main shaft to spin. As a result, only relatively low braking forces are required to prevent spinning.

Abstract: Contaminants are removed from particulate material in an inclined, rotating drum which has an inlet for contaminated material at its upper end, an outlet at its upper end for vaporized contaminants, an inlet for air that is located between the upper end and the lower end, and an outlet for clean particulate material at its lower end. Contaminated particulate material is admitted to the upper end of the drum and conveyed under the influence of gravity and the rotation of the drum to its lower end. A combustion chamber at the lower end of the drum is provided with an air inlet, a fuel burner and an outlet for combustion products. Fuel is burned in the combustion chamber with excess air supplied so that the temperature of the products of combustion is high enough to volatilize the contaminants in the particulate material, but not so high as to incinerate them. A fire tube within the drum conveys the combustion products from the combustion chamber to the upper end of the drum.

Abstract: A paving machine employs a screed heating system using heat from the exhaust system to heat indirectly the screed to the desired temperature. A heat exchange medium is heated by the exhaust system in a first heat exchanger and is then conveyed to a second heat exchanger where it heats the screed. Measures are taken to supply additional heat to the heat exchange medium as may be required to achieve the required heat transfer in the second heat exchanger. The system operates under low pressure and is thus simpler, less expensive, and less likely to fail than high-pressure systems. Preferably, the heat exchange medium is continuously circulated between the first and second heat exchangers in a closed-loop to minimize the amount of heat exchange medium required and to simplify the system. The system is also preferably designed to permit movement of the screed relative to the remainder of the paving machine and to permit flexing of the screed.

Abstract: A screed assembly is disclosed for an asphalt paving machine that is used to pave the surface of a roadway with asphalt concrete paving material. This screed assembly includes a frame portion that is adapted for attachment to the paving machine, and a vibratory screed portion that is adapted for attachment to the frame portion. The vibratory screed portion includes a screed plate that is disposed towards the surface of the roadway, and a vibratory assembly which is mounted to the screed plate so as to impart vibration thereto. This vibratory assembly includes an elongate shaft, means for rotating the shaft, and an eccentric weight that is mounted on the shaft, which weight has a non-symmetrical distribution of mass about the shaft so that vibration will be created upon rotation thereof. The screed assembly also includes means for isolating the vibratory assembly so as to limit the transmission of vibration created thereby to the frame portion.

Abstract: A paving machine employs in combination a gravity feed HMA hopper and a tack spray assembly and storage tank. Use of the gravity feed hopper permits all HMA or other paving material stored therein to be discharged directly on top of the paving machine's distributing auger. Moreover, because the gravity feed hopper takes up a relatively small percentage of the horizontal area of the paving machine, a chassis of standard or near standard dimensions can receive a tack storage tank of sufficient capacity to permit the paving machine to operate an entire day without stopping the machine to refill the storage tank. Therefore, if used in conjunction with an HMA shuttling apparatus, the paving machine can simultaneously coat a surface to be paved with a tack material and pave that surface with HMA for prolonged periods of time without stopping to refill either the HMA hopper of the tack storage tank.

Abstract: A gyratory crusher includes an anti-spin mechanism which couples a lower end of the eccentric shaft of the crusher to the stationary frame of the crusher so as to prevent the eccentric shaft and associated crushing head from spinning when the crusher is not subject to a crushing load. The anti-spin mechanism includes 1) a gear train preferably formed from two sets of intermeshing gears, and 2) a torque limiter which is coupled to the gear train and which releases upon the imposition of a crushing load on the crusher so as to permit relatively slow rotation of the eccentric and crushing head counter to the direction of rotation of the main drive gear or bull gear.

Abstract: A method for desegregating and conveying aggregate includes reorienting aggregate from a side-by-side lateral orientation to a longitudinal orientation. The longitudinally oriented segregated aggregate may then be thoroughly desegregated in a second conveyor. Reorientation preferably occurs as the aggregate is conveyed along a drag slat conveyor which has a notch in the floor of its discharge end which causes larger aggregate at the lateral edges of the conveyor to drop out of the conveyor after smaller aggregate located between the lateral edges.

Abstract: A paving machine has a gravity feed hopper which is capable of delivering by gravity to the paving apparatus substantially all of the paving materials stored in the hopper without employing any internal conveyors. The discharge opening of the hopper is selectively closed by a feeder gate, the degree of opening of which is preferably coordinated with other operating parameters of the machine such as vehicle speed, distributing auger height and/or speed, and screed operation. Use of the gravity feed hopper significantly reduces construction and maintenance costs, provides a more uniform feed of materials from the hopper, and permits the use of a smaller engine. The paving machine as thus constructed is also relatively easy to operate and thus can be controlled by a single operator seated in the vicinity of the screed.

Abstract: A combined soil remediation and HMA plant is provided having a rotary dryer, a rotary soil incinerator, and a refractory lined duct connecting the incinerator to the dryer and serving as a conduit via which hot gases, forming the primary and possibly sole heat source used to heat raw aggregate in the dryer, are conveyed from the incinerator to the dryer. The duct also acts as an afterburner in which volatile organic compounds, particles of contaminated dust, and other combustible products not destroyed in the incinerator are destroyed. The plant further includes a mixer 1) receiving both reclaimed soil from the incinerator and heated and dried aggregate from the dryer and 2) mixing both materials with liquid asphalt and possibly RAP and/or dust from the system's baghouse assembly to form HMA.

Abstract: A rock saw has a cutting wheel and a conveyor assembly capable of retrieving automatically essentially all materials excavated by the cutting wheel and of discharging the retrieved materials into an adjacent truck or the like. The conveyor assembly includes a loading conveyor which is movable from a raised transport position to a lowered operative position. When in its operative position, an inlet end of the loading conveyor is positioned on the ground in a discharge region of the cutting wheel and is biased into engagement with the ground so as not to bounce up and down in operation but so as to ride over rocks and other obstructions without damaging the conveyor. The cutting wheel is both pivotable and slidable with respect to the vehicle mainframe so as to be capable of cutting trenches of radically different depths while still assuring retrieval of essentially all excavated materials by the loading conveyor.

Abstract: A premix burner assembly for heating the combustion chamber of a dryer for an HMA plant, soil remediation plant, or the like is designed to meet the very low emission limitations that are imposed in certain areas such as the southern portion of California. The burner assembly includes a burner, a primary nozzle, an air source connected to the burner, a fuel source, and a fuel injection system connected to the fuel source and to the burner. Premixing is achieved through the supply of a gaseous fuel from the fuel injection system into the burner upstream of the primary nozzle so as to lead to nearly complete premixing of the air and fuel prior to discharge into the combustion chamber, thereby permitting combustion of the fuel with only very small amounts of excess air. Burner efficiency is increased and emissions are further reduced by employing air distribution and control devices upstream of the fuel injection system and by carefully controlling the supply of both air and fuel to the burner.

Abstract: An excavating machine includes a discharge conveyor which is movable (1) from an operative position in which an inlet end thereof is located directly under the outlet end of an associated loading conveyor (2) to a transport position in which the discharge conveyor extends substantially in parallel with the loading conveyor and in which the discharge end thereof is located between the inlet and discharge ends of the loading conveyor--thereby maintaining the discharge conveyor within the dimensional confines of the vehicle on which it is mounted. Movement of the discharge conveyor from its operative position to its stowed or transport position is facilitated by a support assembly including a slide and a turntable assembly. The slide includes a base which is mounted on rails or the like so as to move laterally with respect to the chassis, and the turntable assembly supports the discharge conveyor on the base for rotation about a vertical axis.