A grinder including a motor, a switch operated ON and OFF in accordance with an operation of a switch lever to control a rotation of an output shaft of the motor, a spindle that rotates in accordance with the rotation of the output shaft to rotate a disk-shaped grinding wheel and a brake mechanism controllable with respect to a brake plate that integrally rotates with the output shaft, in a housing, the brake plate includes fins.

In a substrate polishing apparatus where a polishing liquid passes through inside a rotary joint, the rotary joint requires maintenance. There is provided a substrate polishing apparatus that includes: a polishing head for holding a substrate; a rotary table that has a surface to which a first opening portion is provided; a polishing liquid discharge mechanism disposed to the rotary table; and a controller configured to control at least the polishing liquid discharge mechanism. The polishing liquid discharge mechanism includes a first cylinder, a first piston, and a driving mechanism that drives the first piston. The first opening portion is communicated with a liquid holding space defined by the first cylinder and the first piston. The controller controls the driving of the first piston by the driving mechanism to increase and decrease a volume of the liquid holding space.

A grinder includes a brake mechanism configured to brake a spindle and an electrical actuator (a solenoid) that actuates the brake mechanism. The solenoid actuates the brake mechanism in conjunction with a turning OFF of a switch from a driving state of a motor, and releases an actuation of the brake mechanism after a lapse of a predetermined period of time from the turning OFF of the switch.

A grinder includes a brake mechanism configured to brake a spindle and an electrical actuator (a solenoid) that actuates the brake mechanism. The solenoid actuates the brake mechanism in conjunction with a turning OFF of a switch from a driving state of a motor, and releases an actuation of the brake mechanism after a lapse of a predetermined period of time from the turning OFF of the switch.

An upward-opening abrasive cloth roller has a roller below the abrasive cloth. The system has: a support frame mounted on a machine, a roller is disposed on the support frame, a hollow panel is mounted on the machine, and the first side of the panel is pivotally connected to the machine. The two ends of the support frame are respectively provided with individual height adjustment structures, and a panel level adjustment structure is mounted on the machine on below the second side of the panel. With the above two adjustment structures to adjust the level of the roller and the panel, the plate can be easily adjusted for different grinding depths and angles.

An upward-opening abrasive cloth roller has a roller below the abrasive cloth. The system has: a support frame mounted on a machine, a roller is disposed on the support frame, a hollow panel is mounted on the machine, and the first side of the panel is pivotally connected to the machine. The two ends of the support frame are respectively provided with individual height adjustment structures, and a panel level adjustment structure is mounted on the machine on below the second side of the panel. With the above two adjustment structures to adjust the level of the roller and the panel, the plate can be easily adjusted for different grinding depths and angles.

Heat generated during braking is reduced to prevent reduction in braking performance or the service life of the components. A grinder includes a housing, an operable member, a switch operable to be turned on or off in response to an operation on the operable member, a rotational shaft rotatable in response to an operation for turning on the switch, and a brake assembly that applies braking to the rotational shaft with the switch being in an off state and to release the braking applied to the rotational shaft in response to an operation for turning on the switch performed by the operable member. The brake assembly includes a brake member being circular and fixed to the rotational shaft, and multiple pressing members that press the brake member at multiple positions to apply a uniform force to the brake member from radially outward positions toward a center of the brake member.

Heat generated during braking is reduced to prevent reduction in braking performance or the service life of the components. A grinder includes a housing, an operable member, a switch operable to be turned on or off in response to an operation on the operable member, a rotational shaft rotatable in response to an operation for turning on the switch, and a brake assembly that applies braking to the rotational shaft with the switch being in an off state and to release the braking applied to the rotational shaft in response to an operation for turning on the switch performed by the operable member. The brake assembly includes a brake member being circular and fixed to the rotational shaft, and multiple pressing members that press the brake member at multiple positions to apply a uniform force to the brake member from radially outward positions toward a center of the brake member.

Provided is a rotary tool. In the rotary tool, the rotating tip tool is mounted on a spindle by the fixture, and the spindle and the tip tool are rotated by a motor. The rotary tool has a switch which can switch the motor between a rotation state and a stop state, and a control device which controls the rotation of the motor corresponding to the operation of the switch. When the switch is turned off after a required time T elapses after the motor is started, the control device stops the rotary tool (104d, 106d) by performing a common braking operation on the spindle, and when the switch is turned off before the required time T elapses after the motor is started, the control device stops the tip tool (101d) by inertia without applying a braking force.

A brush assembly has a brush holder rotatable about a rotation axis, a ring brush carried on the holder and having an annular array of radially outwardly projecting bristles, and a stop element fixed adjacent the ring brush, of noncircular section. This stop element extends along and is rotatable about a longitudinal axis generally parallel to the rotation axis and projects into the array of bristles.