Abstract: A mounting adapter including a bearing for rotatably mounting a surface processing tool to a tool holder body. The bearing has a rotatable hub including an attachment in an upper portion thereof for non-rotatable attachment to the tool holder body. The mounting adapter includes a rubber flex pad having a periphery and a first aperture. The mounting adapter includes an element supporting the periphery of the rubber flex pad, the element having a second aperture in vertical registry with and beneath the first aperture. The mounting adapter includes an end plug within the second aperture for closing the first aperture. The end plug supports the flex pad from beneath the second aperture.

Abstract: A concrete trowel is disclosed and includes a frame, a drive assembly including a motor mounted on the frame and a drive hub configured to receive torque from the motor, and a rotor rotatable about a rotational axis and including a plurality of blades. The concrete trowel further includes a quick-change coupling for selectively attaching the rotor and the drive hub for co-rotation therewith.

Abstract: A process for additive manufacturing of a resorbable implant to be implanted into a patient includes providing a biocompatible resin including a liquid light-polymerizable material that is resorbable after polymerization and an initiator. The process further includes actuating an additive manufacturing apparatus to expose an amount of the biocompatible resin to light to at least partially cure the exposed amount of biocompatible resin to form a layer of the resorbable implant and actuating the additive manufacturing apparatus to expose at least some additional amount of biocompatible resin to light to at least partially cure the exposed additional amount of biocompatible resin to form an additional layer of the resorbable implant and to at least partially overcure previously cured layers to cause at least some interlayer binding between the previously cured layers and the additional layer.

Abstract: A mounting adapter for mounting a surface processing tool having a rotational or longitudinal axis to at least one spider arm of a rotatable spider assembly of a surface processing apparatus, the spider arm having a leading side and a trailing side as a function of the direction of rotation of the spider assembly. The mounting adapter has a first element for removably attaching the adapter to the spider arm and a second element positioned circumferentially offset behind the first element for positioning the rotational or longitudinal axis of a surface processing tool circumferentially offset behind the trailing side of the spider arm. The first element is an elongate apertured bar and the second element is weld filler material, the bar being connected to said surface processing tool via the weld filler material.

Abstract: A self-propelled power trowel for finishing a concrete surface is equipped with reversible rotors to allow an operator to reverse the direction of rotation of rotor blades. The trowel includes a rigid frame adapted for operation over a concrete surface, a pair of rotor assemblies having rotor blades tiltably connected to the rigid frame for frictionally contacting the concrete surface and supporting the rigid frame thereabove, a prime mover mounted to the rigid frame and operatively coupled to drive the rotor blades of the rotor assemblies in opposite rotational directions. Synchronous or hydraulic motors are configured for causing, responsive to manual controls, reversal of the direction of rotation of the rotor blades.

Abstract: A concrete smoothing assembly having a plurality of blades extending radially from a central hub. The central hub is attachable to a rotating power tool to effectively rotate the blades about a vertical axis. The blades are angled at an offset angle with respect to a horizontal axis, each with a lower working edge adapted to sweep imperfections from a surface of partially dried concrete.

Abstract: A reinforcement assembly removably connectable to a pan of a troweling machine having a rotor assembly with corresponding troweling arms each supporting a trowel blade is provided. The reinforcement assembly comprises a reinforcement member; a first connector connectable to the reinforcement member, the first connector being removably connectable to one of the troweling arms; and a second connector connectable to the reinforcement member, the second connector being removably connectable to the pan. In operation, the reinforcement assembly maximizes a distribution of weight of the troweling machine onto a surface of the pan.

Abstract: A mounting adapter including a bearing for rotatably mounting a surface processing tool to a tool holder body. The bearing has a rotatable hub including an attachment in an upper portion thereof for non-rotatable attachment to the tool holder body. The mounting adapter includes a rubber flex pad having a periphery and a first aperture. The mounting adapter includes an element supporting the periphery of the rubber flex pad, the element having a second aperture in vertical registry with and beneath the first aperture. The mounting adapter includes an end plug within the second aperture for closing the first aperture. The end plug supports the flex pad from beneath the second aperture.

Abstract: An enclosure assembly includes a pan that includes at least one shaft opening. A shroud at least partially surrounds the pan. The shroud extends transversely relative to the pan. A skirt surrounds a perimeter of the shroud and is moveable relative to the shroud.

Abstract: A support structure for a float pan for floating a concrete surface provides an interface between the float pan and a rotating machine. The support structure is characterized by a hub configured for concentric attachment to a rotor, and by trusses that extend radially from the hub, each providing a float pan contact surface and means for attachment to the float pan. Perimetric bracing links the trusses about the perimeter of the support structure. A machine similar to a walk-behind or ride-on trowel but without rotor blades, may incorporate the support structure and operate as a dedicated power flotation machine. Under weight of the machine, the contact surfaces of the trusses conform the float pan to a desired shape or radius of curvature for optimizing a flotation process.

Abstract: The present invention discloses a method of hot recycling repairing by optimizing a proportion of an asphalt mixture on a pavement alignment variation section. According to the method of the present invention, by regulating and optimizing the proportion of a recycled asphalt mixture, internal frictional resistance and cohesion of the recycled asphalt mixture are improved, elastic modulus and shear strength of the recycled asphalt mixture are increased, overall bearing capacity of an asphalt pavement is improved, and diseases such as tracks caused by vehicle loads are effectively resisted. The pavement asphalt mixture is made to adapt to and be enough to bear additional loads increased manifold without generating early defects and road diseases. Therefore, the overall service life of a road is further prolonged.

Abstract: A vibrating device includes a housing with a first and second cases that are connected to a mounting device and are connected to each other with a bridge tube. The mounting plate with the connected housing is removably connected to a blade of a cement smoothing device where the first and second cases are positioned on either side of a handle of the blade. The housing contains one or more motors to evenly impart a vibration to the blade. The housing also contains one or more sensor assemblies which are electrically connected to the one or more motors to selectively engage or disengage a circuit to power or not power the one or more motors. The one or more sensor assemblies are arranged to detect a tilt of the vibrating device to engage or disengage the power.

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 mounting adapter for mounting a surface processing tool having a rotational or longitudinal axis to at least one spider arm of a rotatable spider assembly of a surface processing apparatus, the spider arm having a leading side and a trailing side as a function of the direction of rotation of the spider assembly. The mounting adapter has a first element for removably attaching the adapter to the spider arm and a second element positioned circumferentially offset behind the first element for positioning the rotational or longitudinal axis of a surface processing tool circumferentially offset behind the trailing side of the spider arm. The first element is an elongate apertured bar and the second element is weld filler material, the bar being connected to said surface processing tool via the weld filler material.

Abstract: An adaptive balancing mechanism of dual-head cement trowelling machine includes a water tank, a screw support base, an adjusting screw, a sensor and controller, a counterweight, a stepper motor, an underframe, a guide rail, a guide rail support plate, limit plates, and a transmission member. The controller collects the weight change information of the water in the water tank in real time according to the operation process. Adjust the position of the counterweight in real time by the stepper motor and the adjusting screw to make the two trowel heads in adaptive dynamic balance to the ground pressure.

Abstract: A self propelled power trowel for finishing a concrete surface is equipped with reversible rotors to allow an operator to reverse the direction of rotation of rotor blades. The trowel includes a rigid frame adapted for operation over a concrete surface, a pair of rotor assemblies having rotor blades tiltably connected to the rigid frame for frictionally contacting the concrete surface and supporting the rigid frame thereabove, a prime mover mounted to the rigid frame and operatively coupled to drive the rotor blades of the rotor assemblies in opposite rotational directions. Synchronous or hydraulic motors are configured for causing, responsive to manual controls, reversal of the direction of rotation of the rotor blades.

Abstract: The present invention relates to a device (14) for sanding floor areas, the device comprising a frame, a steering, a motor which is provided to said frame, a subframe (13) rotatably coupled with said motor, said subframe being centrally provided with an adapter (7) along the lower side, a sanding frame (1), said sanding frame being centrally provided with a receiver (2) along the upper side, said receiver receiving said adapter, and at least one holder (5) for sanding elements, said holder being provided along the lower side of said sanding frame and being suitable for the attachment of sanding elements (15). In particular, the subframe is freely supported by the sanding frame, via said adapter and receiver, said adapter and receiver being rotationally coupled. In other aspects, the invention relates to a sanding frame, a sanding element and a method for sanding floor areas, as well as a floor area obtained by application of said method.

Abstract: A vibration float tool comprising a float pad, an enclosed vibrating component affixed to the top of the float pad, a switch affixed to a battery used for activating and deactivating the enclosed vibrating component, a handle affixed to a surface of the enclosed vibrating component and the battery is used for powering the enclosed vibrating component wherein the battery attached to the handle. A method of using the vibrating float tool to level and settle a semi-liquid construction substrate, comprising activating the enclosed vibrating component with the switch, applying the float pad of the vibrating float tool across the semi-liquid construction substrate, leveling the surface of the semi-liquid construction substrate and setting the semi-liquid construction substrate.

Abstract: Powered concrete finishing apparatus including a working head for working the concrete. The working head has a rotatable working surface having a ring shape in contact with the concrete during a finishing operation. The concrete finishing apparatus further includes a motor for driving the working head to perform a rotational working movement on the concrete during the finishing operation. The working surface comprises a clearance for allowing concrete to aggregate within said clearance. The clearance is free of additional working surfaces contacting the concrete during the finishing operation, such as blades, pans, floats or arms, thereby providing an improved finishing of the concrete.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame, a powered drive, and a mechanical control connection. The frame includes a drive housing and a handle to be grasped by a user, with the handle being configured to facilitate manual advancement of the concrete screed in a forward direction. The handle includes a grip and a relatively shiftable user-operated drive controller. The powered drive is operably supported by the drive housing and is configured to rotate a rotatable concrete forming drum.

Abstract: A power unit is configured for use as part of a concrete screed and includes a frame, a powered drive, and a drive coupler. The frame includes a drive housing and a handle to be grasped by a user, with the handle being configured to facilitate manual advancement of the concrete screed in the forward direction. The handle and the drive housing are pivotally attached relative to each other so that the handle is swingable relative to the drive housing about a pivot axis that is transverse to the forward direction. The powered drive is operably supported by the drive housing and includes a rotatable drive shaft. The drive coupler is attached to the drive shaft and is removably attachable to the connection shaft of a rotatable concrete forming drum so that rotation of the drive shaft is imparted to the connection shaft.

Abstract: A vibrating float including an elongate plate, having a substantially planar lower surface configured to be moved across the concrete; a plurality of evenly spaced electric motors coupled to the elongate plate and configured to vibrate the plate; and a handle, coupled to the elongate plate, for use by an operator to control movement of the vibrating float.

Abstract: A support structure for a float pan for floating a concrete surface provides an interface between the float pan and a rotating machine. The support structure is characterized by a hub configured for concentric attachment to a rotor, and by trusses that extend radially from the hub, each providing a float pan contact surface and means for attachment to the float pan. Perimetric bracing links the trusses about the perimeter of the support structure. A machine similar to a walk-behind or ride-on trowel but without rotor blades, may incorporate the support structure and operate as a dedicated power flotation machine. Under weight of the machine, the contact surfaces of the trusses conform the float pan to a desired shape or radius of curvature for optimizing a flotation process.

Abstract: Grouting tiles and/or mosaics today even for large areas such as commercial environments, offices, shopping malls, etc. is achieved using professionals who work through the entire process on their hands and knees. It would be beneficial to provide building contractors, individuals, etc. with a machine to implement some or all of these steps thereby allowing a wider range of tiles and tile effects to be implemented. Equally a handheld unit may be employed by amateurs such as when decorating residential environments in order to improve the quality of their work and reduce the time taken. Such devices according to embodiments of the invention allowing use of smaller tiles, tiling mosaics, etc. without the costs of these visually effective and attractive designs being prohibitive.

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 hydrostatically power self-propelled concrete finishing trowel has at least two coolers in a cooling system of the machine's hydraulic circuit. In the most typical case in which the first cooler is a closed loop oil cooler, the second cooler may take the form of an open loop oil cooler disposed in a flow path connecting one or more low-pressure outlets of the hydrostatic drive system to a reservoir. The closed loop oil cooler actively drops the temperature within the trowel's hydrostatic drive system, while the open loop oil cooler supplements that cooling by reducing the oil temperature in the reservoir.

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: An automatic pitch control system for riding power trowels enables a user to control and automatically adjust trowel blade pitch and height for concrete finishing. The disclosed system provides for blade pitch of separate rotor assemblies to be adjusted independently of one another or synchronously. The disclosed system also provides for a mode of operation that allows the user to completely flatten trowel blades for panning.

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 rigid wheel (18) or roller for a compactor machine, comprising a drum for contacting material to be compacted. The drum has a profiled outer surface including a first cylindrical portion (27) and a second cylindrical portion (29). The first cylindrical portion has a larger rolling diameter than the second cylindrical portion. An inclined portion (24) extends between the first and second cylindrical portions. The area of contact between the outer surface of the drum and refuse, soil or other material to be compacted varies with the depth of penetration of the wheel into the material. The different rolling diameters within the scope of one wheel gives different ground pressures. This means that the pressure applied to the material for compaction varies depending upon the depth of penetration of the wheel. One benefit of this wheel/roller design is to allow improved go anywhere mobility—high floatation where needed changing to heavy ground pressure where conditions demand.

Abstract: A concrete finishing tool includes a body having a chassis, a guard, and frame supports. An extension handle is attached to the body, and a motor is attached to the body and operatively connected to a driving gear and driven gear to rotate blades having a quick change coupling mechanism. An integrated handle is configured on the body and houses a switch for the motor that is powered by a power supply.

Abstract: An automatic speed control system for a power trowel for regulated adjustment of rotational speed of the trowel rotor assemblies. The disclosure provides for and is configurable to automatically regulate trowel speed and can be adapted to utilize advanced control features like cruise control and power management. The disclosed system incorporates several user and feedback inputs in a number of logic patterns for trowel control.

Abstract: An automatic speed control system for a power trowel for regulated adjustment of rotational speed of the trowel rotor assemblies. The disclosure provides for and is configurable to automatically regulate trowel speed and can be adapted to utilize advanced control features like cruise control and power management. The disclosed system incorporates several user and feedback inputs in a number of logic patterns for trowel control.

Abstract: A vehicle for transporting a ride-on trowel includes: a vehicle frame defining a bay sized and shaped to receive the ride-on trowel, including a lower frame surrounding the bay on three sides, a U-shaped rear frame, and an L-shaped upper frame connected at the lower frame and the rear frame; wherein the lower frame is configured to closely match the shape of an outer frame of the ride-on trowel, so that the ride-on trowel will not swing or sway in the bay when supported from the vehicle frame; wheels mounted to the lower frame; guides extending downward from the lower frame, the guides being located to limit motion of the ride-on trowel in both left-right and fore-aft directions with respect to the vehicle frame while being lifted or lowered; means for driving at least one of the wheels; and means for supporting the ride-on trowel from the vehicle frame.

Abstract: A drive train assembly for a ride-on twin rotor concrete finishing machine mounts the main clutch and drive belt arrangement at an unobstructed location on a gear box at one end of the supporting frame where it is readily accessible for changing the drive belt without disassembly of the main drive shaft while maintaining a centrally located engine.

Abstract: An automatic pitch control system for riding power trowels enables a user to control and automatically adjust trowel blade pitch and height for concrete finishing. The disclosed system provides for blade pitch of separate rotor assemblies to be adjusted independently of one another or synchronously. The disclosed system also provides for a mode of operation that allows the user to completely flatten trowel blades for panning.

Abstract: A self-propelled concrete finishing trowel has an integrated transport system that allows the towel to be moved from location to location. The transport system includes a pair of spaced wheel assemblies, each including a pair of wheels that are connected to a frame of the trowel. The wheels of each respective wheel assembly are connected to one another via a powered actuator such as a double acting hydraulic cylinder. The powered actuator is actuatable to raise and lower the first and second wheels from a stowed position in which the wheels are located above the ground and the blades are supported on the ground to a deployed position in which the wheel are supported on the ground and the blades are raised from the ground.

Abstract: A self-propelled concrete finishing trowel has an electronically controlled engine droop control to prevent stalling of the trowel's engine during overload conditions. The engine droop control includes an engine speed sensor that measures operating speed of the engine and a controller that adjusts operation of a hydrostatic drive system of the trowel based on feedback received from the engine speed sensor to reduce the power draw on the engine during overload conditions. The hydrostatic drive system is powered by the engine to rotate one or more finishing blade arrangements, and under normal operating conditions, is driven by a controller to rotate the blade arrangements at an operator desired speed, such as input by a foot pedal. During overloading conditions, the controller overrides the operator input to drive the hydrostatic drive system to match an operating speed supported by the overloaded engine to reduce the power draw on the engine and thereby prevent engine stalling.

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 motor-powered concrete finisher, having a motor and a rotatable circular disc powered by the motor are attached at the end of a counter-balanced extension pole. A handle may be provided at or near the balance point of the extension pole. The motor may be disposed on the rear end of the extension pole, to assist in counterbalancing the weight of the circular disc, hub, front end of the extension pole and other weight on the front end of the extension pole. An angled gear drive on the front end of the extension pole, driven by a shaft extending through the extension pole, has an attachment hub at its end for attachment of the circular disc. The motor may be an internal combustion engine. The concrete finisher may be a weed trimmer having the weed trimmer attachment replaced by a rotatable circular disc.

Abstract: A hand-controlled, curb forming machine that is transformable between different widths and geometries, and between different wheel configurations, to accommodate different concrete curbing. A downwardly projecting, rotating head that rotates about an axis perpendicular to the slab shapes raw concrete into appropriately styled and contoured curbs. A machine frame slidably receives an adjustable, wheeled subframe. A roller on the opposite frame side rides on an opposite curb form. A pivoted handle is reversible. The electric motor is adjustably secured to the frame by a mounting plate movable within follower slots in the frame. A removable adaptor plate disposed on an opposite frame end supports the machine when not in use, but can be removed for normal curb work exposing a form riding roller. When the machine is deployed with monolithic curbs without rebar, the adaptor plate can mount to the subframe to raise the machine by lowering the wheels.

Abstract: Disclosed is an unfolding ride-on machine having a frame, a front cover and back cover supported by the frame, and internal workings supported by the frame and contained within an internal space. A right side cover and left side cover are pivotally connected to the frame. A seat platform is pivotally connected to the front or back covers. Each of the right side cover, left side cover, and seat platform are configured to pivotally transition between a closed configuration and an open configuration. In the open configuration, the internal workings are readily accessible.

Abstract: A self-propelled concrete finishing trowel has an electronically controlled engine droop control to prevent stalling of the trowel's engine during overload conditions. The engine droop control includes an engine speed sensor that measures operating speed of the engine and a controller that adjusts operation of a hydrostatic drive system of the trowel based on feedback received from the engine speed sensor to reduce the power draw on the engine during overload conditions. The hydrostatic drive system is powered by the engine to rotate one or more finishing blade arrangements, and under normal operating conditions, is driven by a controller to rotate the blade arrangements at an operator desired speed, such as input by a foot pedal. During overloading conditions, the controller overrides the operator input to drive the hydrostatic drive system to match an operating speed supported by the overloaded engine to reduce the power draw on the engine and thereby prevent engine stalling.

Abstract: A self-propelled concrete finishing trowel has an integrated transport system that allows the towel to be moved from location to location. The transport system includes a pair of spaced wheel assemblies, each including a pair of wheels that are connected to a frame of the trowel. The wheels of each respective wheel assembly are connected to one another via a powered actuator such as a double acting hydraulic cylinder. The powered actuator is actuatable to raise and lower the first and second wheels from a stowed position in which the wheels are located above the ground and the blades are supported on the ground to a deployed position in which the wheel are supported on the ground and the blades are raised from the ground.

Abstract: In a riding concrete finishing trowel, a stabilizer is operatively disposed between the frame and either the gearbox or a structure that is coupled to the gearbox so as reduce the effects of rotor assembly vibration on the trowel. In one embodiment, the stabilizer takes the form of a gas spring located between the frame and the pitch control post. The stabilizer may be located relatively close to the top of the pitch control post so as to take advantage of the mechanical advantage offered by the spacing between that location and the gearbox.

Abstract: A self-propelled concrete finishing trowel has a power steering system that facilitates operator selection of a desired steering performance response of the trowel. The power steering system includes a controller that communicates operator steering instructions from one or more joysticks and the powered actuators associated with the driven shafts. A selector allows the operator to select one or more preset steering modes, each of which has a different set of steering response characteristics for a given range of joystick motion.

Abstract: A concrete finishing apparatus for smoothing and leveling partially set-up concrete at a support surface includes a frame portion, a first concrete working member and a second concrete working member disposed at the frame portion. The first concrete working member is rotatable about a first axis of rotation that is generally vertical when the first concrete working member is supported at a generally horizontal support surface. The second concrete working member is rotatable about a second axis of rotation that is generally vertical when the second concrete working member is supported at a generally horizontal support surface. The first and second concrete working members engage the partially set-up concrete surface at the support surface and rotate about the first and second axes of rotation to process the concrete surface.

Abstract: A power trowel for treating a concrete surface includes a support frame configured to be moved on the concrete surface. A propane supply vessel is supported by the support frame and is configured to contain propane. The propane supply vessel is positioned to reduce obstructions to the operator's view of the concrete surface. An internal combustion engine is supported by the support frame and is in fluid communication with the propane supply vessel to receive propane therefrom to power the internal combustion engine. One or more rotatable shafts are driven by the internal combustion engine, and one or more trowel blades connect to the one or more rotatable shafts so as to rotate therewith.

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.