Abstract: A linear lost motion mechanism is located within a tubular handle of a machine, such as a concrete finishing machine. The linear lost motion mechanism includes a pitch block configured to selectively frictionally lock with the tubular handle or a component attached to the tubular handle using a biasing spring. The linear lost motion mechanism can perform a number of functions, such as controlling a blade pitch adjustment system of a concrete finishing machine.

Abstract: A blade pitch adjustment system may adjust the pitch of a plurality of blades. A height adjustment assembly adjusts a distance between a rotatable blade assembly and a thrust collar. Adjusting the distance between the assembly and the collar changes the pitch of the blades of the machine. Two or more blade pitch adjustment systems may be adjusted at the same time, at the same rate. For concurrent adjustment, systems are connected to a rotating member by tension cables. A linear actuator rotates the rotating member, changing the tension on the tension cables, actuating the systems to change the pitch of the blade assemblies. The pitch of the blade assemblies may have an offset or bias which may be adjusted for with a sliding member, which may be powered by a linear actuator. The system may be used with a concrete finishing machine.

Abstract: A linear lost motion mechanism is located within a tubular handle of a machine, such as a concrete finishing machine. The linear lost motion mechanism includes a pitch block configured to selectively frictionally lock with the tubular handle or a component attached to the tubular handle using a biasing spring. The linear lost motion mechanism can perform a number of functions, such as controlling a blade pitch adjustment system of a concrete finishing machine.

Abstract: A gearbox for a self-propelled power trowel for finishing a concrete surface having a rigid frame adapted to be disposed over a concrete surface, an engine assembly, at least one rotor assembly. The gearbox uses an input shaft having a first bevel gear, an intermediate shaft having a second bevel gear and a first helical gear, and an output shaft having a second helical gear to connect the engine assembly to the rotor assembly to accomplish a double reduction.

Abstract: An improved gearbox for a self-propelled power trowel for finishing a concrete surface having a rigid frame adapted to be disposed over a concrete surface, an engine assembly, at least one rotor assembly. The improved gearbox uses an input shaft having a first bevel gear, an intermediate shaft having a second bevel gear and a first helical gear, and an output shaft having a second helical gear to connect the engine assembly to the rotor assembly to accomplish a double reduction.

Abstract: A torque applying device for use with a steering mechanism for a riding power trowel, wherein the torque applying device is pivotally attached to a steering lever at the first end, and to the frame of the power trowel at a second end and in longitudinal alignment with the steering lever when the steering lever is in its at-rest position, and capable of arcuate rotation about its second end from a position where its longitudinal axis is in alignment with the steering lever to a position for imparting a torque force to the lever to assist rotation of the lever when the lever is rotated from its at-rest position for purposes of tilting a power trowel gear box.

Abstract: A self-propelled power trowel, for finishing a concrete surface, is provided, having a rigid frame adapted to be disposed over a concrete surface, an engine assembly, and at least a pair of rotor assemblies having rotatable trowel blades. The rotor assemblies are tiltable relative to the frame. Dual-action hydraulic cylinders are provided interconnected between the frame and the rotor assemblies for selectively tilting the rotors to provide steering control to the power trowel. The hydraulic fluid is delivered to the cylinders at variably selectable but constant pressures through the proportional pressure output control valves.