Abstract: A highly stable concrete saw for cutting crack control relief grooves features a stabilized and reinforced carriage. The carriage frame comprises a generally C-shaped, rigid metal weldment having a closed side extending between a closed front and closed rear. The opposite side is partially open at the bottom, but closed at the top by an elevated reinforcing bridge that connects the front and rear of the frame. The frame substantially surrounds and pivotally captivates a rigid subframe supporting the drive motor and the blade assembly. The carriage comprises a pair of rigid, inwardly offset and downwardly projecting tabs at its front and rear. The tabs are line bored to journal elongated axles that mount front and rear pairs of resilient rollers. Angled scraper assemblies projecting downwardly in front of each pair of rollers deflect away loose debris to maintain a smooth travel path for the carriage.

Abstract: A vibration system that fits on top of a conventional truss with minimal alteration. The system comprises a propulsion assembly powering a vibration assembly. The propulsion assembly comprises two parallel rails forming a lateral path between truss ends and supporting a mobile carriage. Each rail comprises abutting segments coextensively surmounting the truss. Each segment attaches at respective truss cross-beams to define a continuous runway for carriage movement. Each segment also defines a channel for a chain rack anchored at opposite truss ends. The carriage comprises an undercarriage supporting an offset platform. The undercarriage comprises a rail-spanning frame with supporting runway tracking wheels. A motor propels the carriage by turning an axle with terminal pinions entrained about the rack. The offset counterbalances the vibration assembly to reduce torsion. A coupling hitch protrudes from the platform opposite the offset to support the vibration assembly.

Abstract: A powered riding trowel comprises a pair of releasable, protective, quick access hoods that may be unlatched to quickly expose the power means for service without structural disassembly. In a preferred embodiment, the twin hoods are hinged to the frame. The trowel seat is mounted on an upper planar surface of a releasable shroud disposed between the hoods. The shroud front and rear are preferably removably latched to the frame. Major portions of the shroud and the hoods are formed from rigid, supportive material having airflow pathways for cooling and ventilating the normally protected trowel interior. In an alternative embodiment both hoods are releasably coupled to the frame by spring biased latches.

Abstract: A powered concrete finishing trowel comprises a variable ratio drive train to power one or more revolving rotors. One or more internal combustion motors power two or more downwardly projecting rotors comprising blades that frictionally contact the concrete surface. The rotors are shaft driven by reduction gear boxes. By tilting the rotors steering forces are developed. A variable gear drive unit comprises a variable ratio pulley driven by the motor. A second pulley drives the gear box input shaft, with a drive belt entrained between the pulleys. A linear actuator projecting outwardly from a stationary mounting plate terminates at a bracket assembly whose opposite end is pivoted to a rigid stabilizer that structurally compliments the linear actuator, establishing a fulcrum action applied to the bracket center. The linear actuator deflects the bracket assembly to axially displace portions of the variable ratio pulley to change the effective pulley diameter.

Abstract: A powered riding trowel comprises a protective, quick access support shroud that may be unlatched to quickly expose the power means for service without structural disassembly. The trowel seat is mounted on top of the upper planar surface of the shroud. The shroud front and rear are preferably formed from rigid, supportive material having airflow pathways for cooling and ventilating the shroud interior. Opposite shroud ends integral with the top surface angularly depend outwardly and downwardly. In the best mode one shroud end is hinged to the trowel frame, and the opposite end is releasably coupled to the frame by spring biased latches. The preferred hinge structure comprises an outer hinge portion formed by a pivotal connection of the bottom of one shroud end. A cooperating inner hinge defined by at least one pair of inner braces is coupled to a pneumatic dampener that pivotally terminates within the shroud interior.

Abstract: A high performance, multiple rotor riding trowel for finishing concrete and hydraulic controls therefor, enabling complete hand control to the operator of steering, propulsion, and blade pitch. A rigid trowel frame mounts 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. A joystick system enables the operator to hand control the trowel with minimal physical exertion. The joystick system activates solenoid control valves that in turn energize the various hydraulic cylinders that tilt the rotors and alter blade pitch. The rotor gearboxes are mounted to tiltable, pivot steering boxes secured to the frame within suitable mounting regions bounded by rigid frame elements. The rotor assembly blades contact plastic concrete to finish the surface while supporting the trowel.

Abstract: A high performance, three engine, three rotor riding trowel for finishing concrete. A rigid, generally triangular frame mounts three downwardly projecting, bladed rotors that frictionally engage the concrete surface therebelow. The rotors on opposite sides of the operator (i.e., to the left or right) rotate in opposite directions, and they are tilted in coincident pivot planes that are parallel with the frame rear. The front rotor is titled in a plane that is perpendicular to the pivoting plane of the other two rotors. Tilting of the rotors with double acting hydraulic cylinders effectuates steering of the apparatus. Joy sticks enable the operator to hand control the trowel with minimal physical exertion. A unique hydraulic powered linkage generates steering forces by tilting the rotors in response to electrical signals. The gearboxes are interchangeable and mounted to tiltable, steering boxes secured to the frame. Each rotor establishes a generally vertical axis of rotation.

Abstract: In a powered riding trowel of the type having at least two adjacent rotor assemblies wherein said rotor assemblies include rotors which are counter rotating relative to one another, and wherein the rotors circumscribe a circular path during operation, the rotor assemblies being affixed to a framework such that the paths circumscribed by the rotors are spaced apart so that tangential forces developed along the circumference of the respective paths do not interact to reinforce one another.

Abstract: A high power, contra-rotating, twin engine riding trowel for finishing concrete comprises twin, downwardly projecting rotors that counter-rotate simultaneously. An operator sits in a seat mounted to the frame and steers the rotors with a pair of primary control levers that tilt the rotors to generate steering forces. The engines counter-rotate while establishing generally coaxial, horizontal axes of rotation. Each engine drives a rotor through a driveshaft. Both driveshafts establish generally coaxial axes of rotation that are generally parallel to the axes of rotation of the engines. Each driveshaft extends to a gearbox to transfer power to the rotor. The gearboxes are interchangeable and mounted to tiltable, pivotable steering boxes secured to the frame. A first reversing linkage couples the lever means to the arm means. A second reversing linkage means is suitably coupled to one rotor gearbox to reverse tilt it for steering.

Abstract: A buffered guard clearance system for riding and manually pushed powered trowels adapted to allow finishing of a slab surface immediately adjacent an obstacle. The system comprises a movable wing displaceably coupled to the trowel guard cage and a buffer system mounted thereto. The wing is displaceable between a deployed position generally aligned with a lower ring of the cage and a retracted position. When retracted, an unguarded segment of the trowel rotor sweep is established that allows the finishing blades to be deployed immediately adjacent a wall or other obstacle. A displaceable coupling for moving the wing between the deployed position and the retracted position extends from the cage to the wing. The coupling comprises a sliding crossmember mounted on two spaced-apart brackets fixed to the cage. The crossmember supports the wing. The coupling may alternatively comprise electromechanical elements for displacing the wing between deployed and retracted positions.