A protective cover assembled on an abrasive belt hand tool. The protective cover comprises an annular base and a tightening component. The annular base comprises a notch, a first clamping arm positioned on one side of the notch, and a second clamping arm positioned on the other side. The first clamping arm is formed with a through hole, the second clamping arm is formed with an assembly hole, the assembly hole does not penetrating through the second clamping arm. The annular base comprises a first state for tightening a protective cover mounting portion when the first clamping arm and the second clamping arm narrow the notch, and the annular base comprises a second state that the first clamping arm and the second clamping arm do not narrow the notch. The tightening component comprises a pull rod penetrating through the through hole and a piece arranged on the pull rod.

A belt sander includes a rotary unit, an oscillating unit, an abrasive belt position detector, a first sensor, a second sensor, and an electric motor control module. The rotary unit includes a retaining seat and an oscillating seat. A lower wheel is pivotally connected to the retaining seat. An upper wheel is pivotally connected to the oscillating seat. An abrasive belt is mounted on the upper wheel and the lower wheel. A recess is formed on the oscillating seat. The oscillating unit includes an electric motor, an eccentric bushing, and a bearing. The bearing is located in the recess. The electric motor drives the upper wheel to oscillate through the eccentric bushing and the bearing, and the abrasive belt is reciprocated left and right. The electric motor is controlled to run or stop running to achieve the function of automatically adjusting the oscillating position of the abrasive belt through the abrasive belt position detector, the first sensor and the second sensor.

A belt sander includes a rotary unit, an oscillating unit, an abrasive belt position detector, a first sensor, a second sensor, and an electric motor control module. The rotary unit includes a retaining seat and an oscillating seat. A lower wheel is pivotally connected to the retaining seat. An upper wheel is pivotally connected to the oscillating seat. An abrasive belt is mounted on the upper wheel and the lower wheel. A recess is formed on the oscillating seat. The oscillating unit includes an electric motor, an eccentric bushing, and a bearing. The bearing is located in the recess. The electric motor drives the upper wheel to oscillate through the eccentric bushing and the bearing, and the abrasive belt is reciprocated left and right. The electric motor is controlled to run or stop running to achieve the function of automatically adjusting the oscillating position of the abrasive belt through the abrasive belt position detector, the first sensor and the second sensor.

A belt loading device for loading an abrasive belt in a closed loop configuration on a machining tool is disclosed. The device includes a base support and a movable part engaged to the base support. The movable part is movable relative to the base support between a biased position and a belt releasing position, the base support and the movable part, while in the biased position, cooperating to maintain the abrasive belt in a fixed position defining a tool engaging area circumscribed by an inner surface of the abrasive belt. A biasing member interfaces between the base support and the movable part to bias the movable part into the biased position.

A belt loading device for loading an abrasive belt in a closed loop configuration on a machining tool is disclosed. The device includes a base support and a movable part engaged to the base support. The movable part is movable relative to the base support between a biased position and a belt releasing position, the base support and the movable part, while in the biased position, cooperating to maintain the abrasive belt in a fixed position defining a tool engaging area circumscribed by an inner surface of the abrasive belt. A biasing member interfaces between the base support and the movable part to bias the movable part into the biased position.

A belt sander includes a rotary unit, an oscillating unit, an abrasive belt position detector, a first sensor, a second sensor, and an electric motor control module. The rotary unit includes a retaining seat and an oscillating seat. A lower wheel is pivotally connected to the retaining seat. An upper wheel is pivotally connected to the oscillating seat. An abrasive belt is mounted on the upper wheel and the lower wheel. A recess is formed on the oscillating seat. The oscillating unit includes an electric motor, an eccentric bushing, and a bearing. The bearing is located in the recess. The electric motor drives the upper wheel to oscillate through the eccentric bushing and the bearing, and the abrasive belt is reciprocated left and right. The electric motor is controlled to run or stop running to achieve the function of automatically adjusting the oscillating position of the abrasive belt through the abrasive belt position detector, the first sensor and the second sensor.

A belt sander includes a rotary unit, an oscillating unit, an abrasive belt position detector, a first sensor, a second sensor, and an electric motor control module. The rotary unit includes a retaining seat and an oscillating seat. A lower wheel is pivotally connected to the retaining seat. An upper wheel is pivotally connected to the oscillating seat. An abrasive belt is mounted on the upper wheel and the lower wheel. A recess is formed on the oscillating seat. The oscillating unit includes an electric motor, an eccentric bushing, and a bearing. The bearing is located in the recess. The electric motor drives the upper wheel to oscillate through the eccentric bushing and the bearing, and the abrasive belt is reciprocated left and right. The electric motor is controlled to run or stop running to achieve the function of automatically adjusting the oscillating position of the abrasive belt through the abrasive belt position detector, the first sensor and the second sensor.

The invention relates to a press-on element 1 for an abrasive belt 30, in particular for wide belt grinding machines, consisting at least of a backing material 10 with a padding 3 and a sliding layer 4. To clearly improve the grinding results, a method and a press-on element 1 based thereon are employed which permits an additional cooling of the padding 3 and thereby the abrasive belt 30. The press-on element 1 here substantially consists of a padding 3 consisting of a spacer fabric. The spacer fabric is manufactured from two loosely woven textile surfaces which are connected to each other by pile threads so that the cooling medium can flow through the padding 3.

The invention relates to a press-on element 1 for an abrasive belt 30, in particular for wide belt grinding machines, consisting at least of a backing material 10 with a padding 3 and a sliding layer 4. To clearly improve the grinding results, a method and a press-on element 1 based thereon are employed which permits an additional cooling of the padding 3 and thereby the abrasive belt 30. The press-on element 1 here substantially consists of a padding 3 consisting of a spacer fabric. The spacer fabric is manufactured from two loosely woven textile surfaces which are connected to each other by pile threads so that the cooling medium can flow through the padding 3.