A saw blade positioning mechanism for an annular sawing machine includes a protective case, two first driven wheels, two second driven wheels, and an adjustment component. The protective case conceals a portion of an annular saw blade. The first and second driven wheels are rotatably disposed at two opposing ends of the protective case and abut against two opposing lateral sides of the annular saw blade, respectively. The adjustment component is disposed at the protective case to drive the protective case to move in the radial direction of the annular saw blade relative to the annular saw blade. The position of the protective case is adjusted with the adjustment component such that the first and second driven wheels get positioned in place synchronously with displacement of the protective case. The protective case can be demounted so that the first and second driven wheels are simultaneously removed and changed.

A protective apparatus and a machine tool are provided. The machine tool includes an operational element, a driving element, and the protective apparatus. The operational element and the driving element are disposed on machine table. The protective apparatus includes an insulating unit, conducting unit, capacitance sensor, and control unit. The insulating unit is disposed between the operational element and the driving element. The driving element drives the operational element by the insulating unit. The conducting unit contacts the operational element. The capacitance sensor electrically connects the conducting unit for sensing capacitance of the conducting unit. The control unit electrically connects the capacitance sensor and the driving element and determines whether a user approaches the operational element based on the capacitance. When the control unit detects that the distance between the user and the operational element is too close, the control unit stops the operation of the operational element.

A table saw includes a base assembly, a table assembly supported by the base assembly, and a saw assembly supported by the base assembly. The saw assembly has a motor having a motor output shaft and a power train assembly. The motor is configured to rotate the motor output shaft at a first rotational speed. The power train assembly includes an intermediate shaft, a first gear stage, an arbor shaft, and a second gear stage. The first gear stage is configured to transmit rotation of the motor output shaft at the first rotational speed to rotation of the intermediate shaft at a second rotational speed, which is less than the first rotational speed. The second gear stage is configured to transmit rotation of the intermediate shaft at the second rotational speed to rotation of the arbor shaft at a third rotational speed, which is greater than the second rotational speed.

A pivotable log saw is movable between an operating position and a maintenance position. The saw includes: a housing; a turntable pivotably mounted to the housing to rotate around an axis; a saw arm pivotably mounted to the turntable to rotate around another axis; an arm-driving motor mounted to the turntable, the arm-driving motor being connected to the saw arm and controlling slope of the saw arm; a blade-driving motor mounted to the saw arm, a saw blade mounted to the saw arm, and connection between the blade-driving motor and the saw blade wherethrough the blade-driving motor drives rotation of the saw blade; and a locking mechanism adapted, in a locked position, to lock the turntable in the operating position, and, in an unlocked position, allows the turntable to rotate in a maintenance position.

A fluid-driven ring saw includes a ring saw blade that is supported and driven by a fluid. The fluid-driven ring saw can include one or more pairs of fluid nozzles. Each pair of fluid nozzles can include a first fluid nozzle separated from a second fluid nozzle by a gap. The ring blade can be positioned within the gap. The ring blade can include a plurality of holes. The one or more pairs of fluid nozzles can deliver fluid jets that impinge upon the plurality of holes of the ring blade to drive rotation of the ring blade. The ring blade can be driven without direct contact of a mechanical linkage, such as a belt or chain. The ring blade can be relatively thinner than ring blades driven by mechanical linkages.

A cross-cutting circular saw device comprising: a frame (1); a guide (10) carried by the frame (1) and adapted to span an object (5) to be cross-cut by sawing; a carriage (3) mounted for reciprocal movement along the guide (10); at least one circular saw blade (4A, 4B) carried by the carriage (3); a motor (11) for moving the carriage (3) and rotating said at least one saw blade (4A, 4B), said motor (11) being fixed to the frame (1); a first transmission (2) arranged between the motor (11) and the carriage (3) for transforming an output of the motor to a reciprocating movement of the carriage (3) along the guide (10); and a second transmission (8, 9) arranged between the carriage (3) and the at least one saw blade (4A, 4B) for transforming the reciprocating movement of the carriage (3) to a rotation of said at least one saw blade (4A, 4B).

A handheld, hand-guided cutting-off machine, which includes a rotating cutting-off wheel, a supporting housing part (36), an output shaft, which is rotatably supported around an output axis (40), a drive motor, a transmission mechanism, which connects the drive motor to the output shaft, a flange (41) and a safety guard (24), which covers the cutting-off wheel over a covering area. The cutting-off wheel is rotatably fixedly mounted on the output shaft with the aid of the flange (41) and surrounded by the safety guard (24). The safety guard (24), the supporting housing part (36) and the transmission mechanism have maximum distances from the output axis (40) over an outcut angle (), which are smaller than or equal to half the flange diameter (d.sub.f).

A work tool (100) comprising: a cutting chain (110), a drive mechanism for driving the cutting chain (110), an annular member (120) arranged rotatably supported by one or more support rollers (130,140,150), wherein the annular member comprises a rim (230) adapted to support the cutting chain (110) during cutting, and a support wheel (160) arranged distanced from the annular member (120), wherein the cutting chain (110) is arranged supported on a rim segment (102) of the annular member (110) forming part of a cutting area of the tool (100) and supported on a rim segment (103) of the support wheel (160) in a direction away from the cutting area of the tool (100). An annular member and a method of producing an annular member are also disclosed.

A saw blade positioning mechanism for an annular sawing machine includes a protective case, two first driven wheels, two second driven wheels, and an adjustment component. The protective case conceals a portion of an annular saw blade. The first and second driven wheels are rotatably disposed at two opposing ends of the protective case and abut against two opposing lateral sides of the annular saw blade, respectively. The adjustment component is disposed at the protective case to drive the protective case to move in the radial direction of the annular saw blade relative to the annular saw blade. The position of the protective case is adjusted with the adjustment component such that the first and second driven wheels get positioned in place synchronously with displacement of the protective case. The protective case can be demounted so that the first and second driven wheels are simultaneously removed and changed.

A ring saw includes a ring saw blade, a tool holder that guides the ring saw blade in a cutting plane, a motor, and a driving wheel where the ring saw blade is drivable in the cutting plane by the driving wheel and the driving wheel is coupled to the motor. The driving wheel is mounted in a bearing block so as to be rotatable about a drive axis perpendicular to the cutting plane. The bearing block is movable parallel to the cutting plane.