A sealing portion on a lower end of a cover portion of a spindle cover has an upper side surface and a lower side surface that are inclined toward an outer circumferential surface of a spindle. A larger-diameter disk and the outer circumferential surface of the spindle define therebetween a second gap that is narrower than a first gap defined between the spindle and the cover portion. The second gap is effective to prevent a processing waste liquid from entering between the spindle and the spindle cover to prevent a solid waste contained in the processing waste liquid from sticking to the spindle. The spindle is thus prevented from becoming less liable to rotate smoothly due to solid waste deposits.

A dust collector in one aspect of the present invention comprises a dust collection portion, a communication portion, and an interlock operation control portion. When the communication portion receives an interlock command transmitted from an electric working machine, the interlock operation control portion makes the dust collection portion operate interlocking with the electric working machine. The interlock operation control portion includes a storage portion, in which identification information specific to the electric working machine with which the dust collection portion is to be made to perform the interlock operation is stored.

A dust collector in one aspect of the present invention comprises a dust collection portion, a communication portion, and an interlock operation control portion. When the communication portion receives an interlock command transmitted from an electric working machine, the interlock operation control portion makes the dust collection portion operate interlocking with the electric working machine. The interlock operation control portion includes a storage portion, in which identification information specific to the electric working machine with which the dust collection portion is to be made to perform the interlock operation is stored.

An illuminating drywall sponge device provides a drywall sanding/scraping tool having tapered cavities that securely retain an illumination mechanism, such that the work surface being sanded is illuminated during sanding operations; and a marking mechanism for marking the illuminated work surface. The sponge light device provides a housing through which the sanding function is primarily performed. The housing has a block or rectangular shape, and walls with an abrasive material. The housing also has multiple tapered cavities formed at the walls of the housing, oriented coplanar with the surface being sanded. An illumination mechanism fits into the cavity. The illumination mechanism orients in the cavity to throw light outwardly from the edge of the housing. A grommet fits into the outer region of the cavities to help stabilize and fasten the illumination mechanism in the cavities. A retractable marking mechanism may also insert into the cavity.

An illuminating drywall sponge device provides a drywall sanding/scraping tool having tapered cavities that securely retain an illumination mechanism, such that the work surface being sanded is illuminated during sanding operations; and a marking mechanism for marking the illuminated work surface. The sponge light device provides a housing through which the sanding function is primarily performed. The housing has a block or rectangular shape, and walls with an abrasive material. The housing also has multiple tapered cavities formed at the walls of the housing, oriented coplanar with the surface being sanded. An illumination mechanism fits into the cavity. The illumination mechanism orients in the cavity to throw light outwardly from the edge of the housing. A grommet fits into the outer region of the cavities to help stabilize and fasten the illumination mechanism in the cavities. A retractable marking mechanism may also insert into the cavity.

An ultrasonic resonator support structure 10 including a holder 17 supports an ultrasonic resonator 16 at both sides such that the ultrasonic resonator 16 is rotatable to the holder 17. The ultrasonic resonator 16 includes an ultrasonic horn 13 with a machining tool 12 attached, and a first booster 14 and a second booster 15 coaxially fixed one by one to both ends in the axial directions of the ultrasonic horn 13. The holder 17 has a rolling bearing mechanism 18 that rotatably supports the first booster 14 side of the ultrasonic resonator 16 and a gas bearing mechanism 19 that rotatably supports the second booster 15 side of the ultrasonic resonator 16.

A machine tool deceleration device, in particular a hand-held machine tool deceleration device, for a portable machine tool, includes at least one magnetic deceleration unit. The magnetic deceleration unit includes at least one movably mounted claw segment element that is configured to change at least one parameter of a magnetic field of the magnetic deceleration unit.

A machine tool deceleration device, in particular a hand-held machine tool deceleration device, for a portable machine tool, includes at least one magnetic deceleration unit. The magnetic deceleration unit includes at least one movably mounted claw segment element that is configured to change at least one parameter of a magnetic field of the magnetic deceleration unit.

A bench grinder safety and monitoring system for maintaining worker safety while using a bench grinder having a contactor wheel, a tool rest proximate the contactor wheel defining a tool rest gap and having a tongue guard proximate the contactor wheel defining a tongue guard gap. The system includes a first optical sensor situated within in the tool rest gap having an emitter portion coupled to the tool rest adjacent a first side of the contactor wheel and a receiver portion coupled to the tool rest adjacent a second side of the contactor wheel, the emitter portion configured to project a beam of light across the tool rest gap toward the receiver portion. A controller in data communication with the receiver portion of the first optical sensor, is configured to determine if the light beam is received by the receiver portion and, if so, to de-energize the motor.

A bench grinder safety and monitoring system for maintaining worker safety while using a bench grinder having a contactor wheel, a tool rest proximate the contactor wheel defining a tool rest gap and having a tongue guard proximate the contactor wheel defining a tongue guard gap. The system includes a first optical sensor situated within in the tool rest gap having an emitter portion coupled to the tool rest adjacent a first side of the contactor wheel and a receiver portion coupled to the tool rest adjacent a second side of the contactor wheel, the emitter portion configured to project a beam of light across the tool rest gap toward the receiver portion. A controller in data communication with the receiver portion of the first optical sensor, is configured to determine if the light beam is received by the receiver portion and, if so, to de-energize the motor.