Abstract: A dedicated concrete surface polisher comprises a frame and powered chassis substantially resembling a twin rotor riding trowel, equipped with a plurality of diamond polishing pucks, and mounting apparatus for maintaining flat puck contact with the lower concrete surface. Each rotor supports an intermediate drive plate driven by a hydraulic motor. The intermediate drive plate comprises a circular ring plate that is reinforced by a substantially rigid, winged drive collar. Each drive plate supports a plurality of radially spaced apart polishing rotors that project into contact with the concrete surface being treated. Each polishing rotor is secured to the ring plate. The polishing rotors support a plurality of radially spaced apart, downwardly projecting, diamond-equipped pucks that frictionally bear against the concrete surface for polishing and abrading in response to rotor rotation.

Abstract: A roller tube concrete finishing machine includes retractable vibration gangs that can be selectively immersed within wet concrete and then retracted with parallelogram linkage. Spaced-apart, drive parallel rollers are journaled between frame ends for supporting and propelling the machine upon and between parallel form rails. A front roller provide a strike-off function. The vibration gangs are deployed by a retractable, parallelogram linkage that moves them forwardly and downwardly for operation, or which retracts the vibrators inwardly and upwardly relative to the frame. When the vibrators are retracted, the are withdrawn upwardly from the concrete and retracted rearwardly towards the machine front to reduce machine dimensions. Substantial retraction of the vibrators prevents subsequent interference with the rebar below. Vibrator retraction reduces overall machine dimensions for clearance and shipping purposes, with gang vibration arrays nested upwardly and inwardly proximate the front of the machine.

Abstract: An electrically powered, self-propelled cart for safely delivering heavy loads, such as concrete, within job sites with unlevel, irregular, or sloped terrain. A cargo bucket is tiltable over front drive wheels for transporting and dumping cargo. Electric drive motors associated with a transaxle propel wheels at a selectable speed in response to an electric control module. A steering column rotates in response to manually operated handle bars and activates a sensor to generate signals delivered to the control module for throttle adjustments. The sensor may be a linear potentiometer, a rotary differential transformer or a rotary encoder or shaft encoder measuring angular displacement. Extreme steering displacements will electrically reduce cart speed notwithstanding the previous speed setting chosen by the operator through the steering column.

Abstract: A concrete finishing and forming machine adapted for rail trackbed deck construction accommodates various plinths and channels needed for light rail construction. The adjustably configurable machine comprises a rigid frame disposed above a deck by vertically upright, adjustable jack stands supported at their bottoms by wheeled, powered bogies adapted to traverse upon suitable rails on opposite sides of the deck. The jack-stands may be connected to supporting swing arms that extend from pivot sleeves enabling to angularly swing out from the frame. A slidable carriage that is longitudinally displaceable within the frame supports at least one downwardly extending, vertically adjustable paving head having a tool that, when immersed within wet concrete and then horizontally displaced, strikes off elongated, smoothed channels resembling pathways upon the concrete.

Abstract: An adaptor assembly for concrete finishing trowels that enables efficient polishing of concrete surfaces, and trowels equipped with said adaptors. A large, rigid, circular adaptor disk supports a plurality of spaced-apart polishing rotors that project into contact with the concrete surface being treated. Each polishing head is rotatably secured to the adaptor disk with a spindle assembly including suitable alignment bearings. The spindle assembly secures a rigid header beneath the adaptor disk that sandwiches a resilient, annular coupler between itself and a rigid driver plate beneath the coupler. Bosses on the coupler insure spacing and enable proper flexure. The driver plate removably mounts a resilient finishing ring, that supports a plurality of radially spaced apart, downwardly projecting, diamond-equipped pucks that frictionally bear against the concrete surface for abrading and polishing.

Abstract: A roller tube concrete finishing machine includes retractable vibration gangs that can be selectively immersed within wet concrete and then retracted with parallelogram linkage. Spaced-apart, drive parallel rollers are journaled between frame ends for supporting and propelling the machine upon and between parallel form rails. A front roller provide a strike-off function. The vibration gangs are deployed by a retractable, parallelogram linkage that moves them forwardly and downwardly for operation, or which retracts the vibrators inwardly and upwardly relative to the frame. When the vibrators are retracted, the are withdrawn upwardly from the concrete and retracted rearwardly towards the machine front to reduce machine dimensions. Substantial retraction of the vibrators prevents subsequent interference with the rebar below. Vibrator retraction reduces overall machine dimensions for clearance and shipping purposes, with gang vibration arrays nested upwardly and inwardly proximate the front of the machine.

Abstract: A steerable, self-propelled cart for safely delivering heavy loads, such as concrete, within job sites with unlevel, irregular, or sloped terrain. A cargo bucket is tiltable over front drive wheels for transporting and dumping cargo. Hydraulic drive motors driven by a hydraulic pump propel rear wheels at a selectable speed. Steering handlebars rotate a steering column that turns the rear wheels. A throttle cable extending from the handlebars controls the throttle setting by pivoting a throttle lever mounted on the hydraulic pump. Limiting linkages extend from flanges on an anchor bracket secured to the steering column to a bridge on the throttle lever. As the steering column rotates, the limit linkages are wound partially about it, pivoting the throttle lever by pulling on the bridge, reducing pump speed. Heavy steering displacements will retract the throttle lever to reduce cart speed notwithstanding the previous speed setting chosen by the operator via the cable.

Abstract: A modular, continuously variable ratio transmission adapted to be coupled between the drive motor of a dual rotor riding trowel and the lower drive train. First and second rigid, generally planar frame plates are secured in parallel relation by a plurality of spacers. The first fame plate has a clearance orifice for admitting a portion of the trowel engine. A stub shaft receives input power and rotates a first pulley that drives a second pulley with a reduced diameter. A first jackshaft driven by said second pulley drives a variable CVT drive pulley affixed externally of the module. A second variable drive pulley coupled to said first variable drive pulley by a belt drives a second jackshaft splined to a fifth pulley that is coupled to a sixth pulley having a diameter greater than the diameter of said fifth pulley. The sixth pulley is coupled to trowel gearbox drive shafts.

Abstract: A steerable, self-propelled cart for safely delivering heavy loads, such as concrete, within job sites with unlevel, irregular, or sloped terrain. A cargo bucket is tiltable over front drive wheels for transporting and dumping cargo. Hydraulic drive motors driven by a hydraulic pump propel rear wheels at a selectable speed. Steering handlebars rotate a steering column that turns the rear wheels. A throttle cable extending from the handlebars controls the throttle setting by pivoting a throttle lever mounted on the hydraulic pump. Limiting linkages extend from flanges on an anchor bracket secured to the steering column to a bridge on the throttle lever. As the steering column rotates, the limit linkages are wound partially about it, pivoting the throttle lever by pulling on the bridge, reducing pump speed. Heavy steering displacements will retract the throttle lever to reduce cart speed notwithstanding the previous speed setting chosen by the operator via the cable.

Abstract: A high performance, multiple rotor, hydraulically driven riding trowel for finishing concrete includes a rigid trowel frame with two or more downwardly-projecting, bladed rotor assemblies that frictionally engage the concrete surface while supporting the trowel. The rotor assemblies are tilted with double acting hydraulic cylinders to effectuate steering and control. A seating arrangement supports an operator. A special ventilation path is provided to prevent overheating of the operator area. cooling compartment adjacent the seating region, Pathways are established by a cooling compartment enclosed by a shroud having at least one side ventilation orifice, a cooler assembly disposed within the cooling compartment; the cooler assembly comprising a grill, a plenum with a heat exchanger adjacent said grill and a fan adjacent said heat exchanger, the plenum having open sides and a closed bottom to prevent air pathways through the seating region.

Abstract: A power riding trowel for finishing concrete comprising rotors turned by gearboxes driven by gearbox driveshaft's linked to the moor output by CVT gear ratio control. The motor output shaft drives a first jackshaft driven at a higher speed than the motor RPM. A CVT pulley assembly comprising first and second CVT pulleys and a CVT belt entrained between them has a first CVT pulley driven by the first jackshaft. A second jackshaft splined to the second CVT pulley drives the gearbox driveshaft at a speed lower than said second jackshaft to operate the rotor means at a proper speed and torque.

Abstract: A dual rotor, manually steered riding trowel comprises powered, downwardly projecting rotors driven by reduction gear boxes that are tilted by parallel levers beneath the machine. A pair of vertical hand steering levers actuate the parallel levers to tilt the rotors. Each rotor may be swiveled in an arc parallel with the biaxial plane to produce pivoted fore and aft trowel movement. At least one rotor responds to lateral movements of one or both steering levers by tilting in an arc perpendicular to the biaxial plane, moving the trowel left or right. To emulate prior Allen trowels, lateral movements of one of the hand levers is mechanically disabled with a transformation link anchored to the frame. The transformation link may be disconnected from the frame and instead connected to the foot of the companion hand steering lever, allowing both steering levers to pivot laterally, resulting in a different steering “feel.

Abstract: A dual rotor, manually steered riding trowel comprises powered, downwardly projecting rotors driven by reduction gear boxes that are tilted by parallel levers beneath the machine. A pair of vertical hand steering levers actuate the parallel levers to tilt the rotors. Each rotor may be swiveled in an arc parallel with the biaxial plane to produce pivoted fore and aft trowel movement. At least one rotor responds to lateral movements of one or both steering levers by tilting in an arc perpendicular to the biaxial plane, moving the trowel left or right. To emulate prior Allen trowels, lateral movements of one of the hand levers is mechanically disabled with a transformation link anchored to the frame. The transformation link may be disconnected from the frame and instead connected to the foot of the companion hand steering lever, allowing both steering levers to pivot laterally, resulting in a different steering “feel.

Abstract: A power riding trowel for finishing concrete comprising rotors turned by gearboxes driven by gearbox driveshaft's linked to the moor output by CVT gear ratio control. The motor output shaft drives a first jackshaft driven at a higher speed than the motor RPM. A CVT pulley assembly comprising first and second CVT pulleys and a CVT belt entrained between them has a first CVT pulley driven by the first jackshaft. A second jackshaft splined to the second CVT pulley drives the gearbox driveshaft at a speed lower than said second jackshaft to operate the rotor means at a proper speed and torque.

Abstract: High performance, multiple rotor, hydraulically driven riding trowels for finishing concrete have unloader valve circuitry for controlling hydraulic pressure. Each trowel has a rigid frame with two or more downwardly-projecting, bladed rotor assemblies that finish concrete. The rotor assemblies are tilted manually or hydraulically to effectuate steering and control. Blade pitch is controlled manually or hydraulically. The unloader valve system monitors drive pump pressure with a shuttle valve to derive an unloader pilot signal. A sequence valve responds to the unloader pilot signal to control a pressure valve that bypasses the normal foot control valve in an overpressure situation. The pressure control head signal normally applied to the hydraulic drive motor control heads is modified with a feedback signal to automatically control the associated pump swash plates. A gearbox may be disposed between the drive motors and rotors. Piston type and gear and vane type motors may power the rotors.

Abstract: A high performance, multiple rotor, hydraulically driven riding trowel for finishing concrete includes a rigid trowel frame with two or more downwardly-projecting, bladed rotor assemblies that frictionally engage the concrete surface. The rotor assemblies are tilted with double acting hydraulic cylinders to effectuate steering and control. Double acting hydraulic cylinders also control blade pitch. Hydraulic pressure to the rotors is monitored and controlled by an unloader valve system that monitors drive pump pressure with a shuttle valve to derive an unloader pilot signal. A sequence valve responds to the unloader pilot signal to control a pressure valve that bypasses the normal foot control valve in an overpressure situation. The pressure control head signal normally applied to the hydraulic drive motor control heads is modified with a feedback signal to automatically control the associated pump swash plates.

Abstract: Methods and apparatus for screeding freshly placed concrete in which the acoustic impedance of the treating equipment is made substantially equal to the acoustic impedance of the concrete slab. Portions of the screed contacting the plastic concrete are matched to an acoustic impedance approximating the acoustic impedance of plastic concrete, promoting the energy transferred to the concrete. The acoustic matching material is fabricated from a material that has an acoustic impedance within 67% to 150% of the acoustic impedance of the concrete being finished. The acoustic matching material has an abrasion resistance of no greater than 150 measured using ASTM Method G-65 where steel is given a rating of 100. The preferred matching material comprises ultra-high molecular weight polyethylene (UHMWPE) plastic.

Abstract: Pans for power finishing freshly placed concrete in which the acoustic impedance of the treating equipment is made substantially equal to the acoustic impedance of the concrete slab being treated. Preferably, a powered, twin rotor riding trowel is provided with a pair of circular finishing pans that are attached to the conventional rotor blades used later in the finishing process. The pans are characterized by an acoustic impedance approximating the acoustic impedance of plastic concrete, thereby optimizing the energy transferred to the concrete. Preferred pans comprise ultra-high molecular weight polyethylene (UHMWPE) plastic. During troweling, the pans are frictionally revolved over the plastic concrete for finishing the surface without prematurely sealing the uppermost slab surface. Through the disclosed troweling method, a highly stable concrete surface results, and delamination is minimized. Alternative troweling uses pans coated with layered impedance matching material.

Abstract: Methods and apparatus for power finishing freshly placed concrete in which the acoustic impedance of the treating equipment is made substantially equal to the acoustic impedance of the concrete slab being treated. Preferably, a powered, twin rotor riding trowel is provided with a pair of circular finishing pans that are attached to the conventional rotor blades used later in the finishing process. The pans are characterized by an acoustic impedance approximating the acoustic impedance of green concrete, thereby optimizing the energy transferred to the concrete. Preferred pans comprise ultra-high molecular weight polyethylene (UHMWPE) plastic. During troweling, the pans are frictionally revolved over the green concrete for finishing the surface without prematurely sealing the uppermost slab surface. Through the disclosed troweling method, a highly stable concrete surface results, and delamination is minimized. Alternative troweling uses pans coated with layered impedance matching material.