A floor polishing or grinding pad assembly is provided. In one aspect, a polishing or grinding pad assembly employs a fibrous pad, a reinforcement layer or ring, and multiple floor-contacting disks. In another aspect, the reinforcement layer includes a central hole through which the fibrous pad is accessible and the fibrous pad at the hole has a linear dimension greater than a linear dimension of one side of the adjacent reinforcement layer. In yet another aspect, at least one of the floor-contacting disks has an angle offset from that of a base surface of the disk, the fibrous pad and/or the reinforcement layer. A further aspect employs a smaller set of disks alternating between and/or offset from a larger set of the disks. In another aspect, the reinforcement layer includes a wavy or undulating internal edge shape.

A floor polishing or grinding pad assembly is provided. In one aspect, a polishing or grinding pad assembly employs a fibrous pad, a reinforcement layer or ring, and multiple floor-contacting disks. In another aspect, the reinforcement layer includes a central hole through which the fibrous pad is accessible and the fibrous pad at the hole has a linear dimension greater than a linear dimension of one side of the adjacent reinforcement layer. In yet another aspect, at least one of the floor-contacting disks has an angle offset from that of a base surface of the disk, the fibrous pad and/or the reinforcement layer. A further aspect employs a smaller set of disks alternating between and/or offset from a larger set of the disks. In another aspect, the reinforcement layer includes a wavy or undulating internal edge shape.

A concrete grinder has a rotating planetary gearbox with counter rotating tooling plates attached. The planetary gearbox is powered directly from a trowel gearbox output shaft, which is connected to a center bore of the planetary gearbox. As the planetary gearbox rotates, tooling shafts are forced to counter rotate because the input shaft of the planetary gearbox is connected to a fixed pulley or sprocket. The planetary gearbox is sealed to keep water, dust or slurry from entering.

A concrete grinder has a rotating planetary gearbox with counter rotating tooling plates attached. The planetary gearbox is powered directly from a trowel gearbox output shaft, which is connected to a center bore of the planetary gearbox. As the planetary gearbox rotates, tooling shafts are forced to counter rotate because the input shaft of the planetary gearbox is connected to a fixed pulley or sprocket. The planetary gearbox is sealed to keep water, dust or slurry from entering.

A method of grinding a workpiece includes a holding step of holding the workpiece on a flat holding surface of a holding table and a grinding step of rotating a grinding wheel to turn grindstones along an annular track while rotating the holding table, and bringing the grindstones into grinding contact with an upper surface of the workpiece to thereby grind the workpiece. The grinding step includes the step of bringing the grindstones into grinding contact with the upper surface of the workpiece in a state where the annular track is closest to the holding surface in an area between a point above a center of the holding surface and a point above an outer circumferential end of the holding surface.

The invention relates to a device (100) for the grinding and/or polishing of planar surfaces, comprising a grinding and/or polishing tool (20), a frame (40), a workpiece (32) or a holder (30) for at least one workpiece, and a means (10) for moving the frame and the workpiece holder (30) with the workpiece, characterized in that the device (100) is set up in such a way that a loose bearing is formed between the workpiece (32) or the workpiece holder (30) and the frame (40), and the means (10) for moving the frame (40) and the workpiece (32) or the workpiece holder (30, 30′) with the at least one workpiece (32) is configured in such a way that the workpiece (32) or the workpiece holder (30) with the at least one workpiece (32) is guided in a plane which is predetermined by the surfaces of the at least one workpiece (32) resting on the grinding and/or polishing tool (20).

The invention also relates to a method for the polishing of planar optics by using the device (100).

The invention relates to a device (100) for the grinding and/or polishing of planar surfaces, comprising a grinding and/or polishing tool (20), a frame (40), a workpiece (32) or a holder (30) for at least one workpiece, and a means (10) for moving the frame and the workpiece holder (30) with the workpiece, characterized in that the device (100) is set up in such a way that a loose bearing is formed between the workpiece (32) or the workpiece holder (30) and the frame (40), and the means (10) for moving the frame (40) and the workpiece (32) or the workpiece holder (30, 30′) with the at least one workpiece (32) is configured in such a way that the workpiece (32) or the workpiece holder (30) with the at least one workpiece (32) is guided in a plane which is predetermined by the surfaces of the at least one workpiece (32) resting on the grinding and/or polishing tool (20).

The invention also relates to a method for the polishing of planar optics by using the device (100).

A handheld pole sander is provided including an elongate body having two ends, an electric motor electrically controlled by control electronics, and a sanding head attached via a pivot mechanism to a first end of the elongate body. The sanding head includes a hood and an output spindle projecting from the hood and rotatably driven by the electric motor. At least part of the elongate body includes a heat conductive part being at least partially made of heat conductive material. The control electronics are mounted on the elongate body adjacent to or in direct contact with the heat conductive part of the elongate body.

A pole sander is provided including an elongate body including a passageway for passage of air, an electric motor, and a sanding head attached via a pivot mechanism to a first end of the elongate body. The sanding head includes a hood including a plate and a sidewall to form a chamber, an output spindle projecting from the hood and rotatably driven by the electric motor, and a tubular passage including a first end forming an opening and a second end coupled to an aperture formed through the plate. A flexible pipe is disposed between the passageway at the first end of the elongate body and the opening of the tubular passage to fluidly connect the passageway to the chamber. The tubular passage is oriented at least partially around a portion of the output spindle in a turning direction of the output spindle and extending angularly from the plate.

A pole sander is provided including an elongate body having a longitudinal axis, and a sanding head attached via a pivot mechanism to a first end of the elongate body. The sanding head includes a hood including a plate and a sidewall to form a chamber, an output spindle projecting through the hood into the chamber, and an electric motor mounted on the hood and configured to rotatably drive the output spindle about a rotational axis. The pivot mechanism allows the sanding head to pivot around a pivot axis that intersects the sanding head forward of at least one of a centre of gravity of the sanding head or the rotational axis of the output spindle relative to the elongate body when the longitudinal axis of the elongate body is located parallel to the plane of the plate.