# US 12,179,311 B2 · Dust cover for a cutting grinder

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- Number: US 12,179,311 B2
- Document ID: US12179311B2
- Status: Granted
- Kind: B2
- Application number: 16/605,633
- Filed: 2018-04-16
- Published: 2020-04-23
- Granted: 2024-12-31
- Earliest claimed: 2017-04-20
- Assignees: Hilti Aktiengesellschaft
- Applicants: Hilti Aktiengesellschaft
- Inventors: Kevin Kuhlmann
- Web page: https://patentgrep.com/patent/US12179311B2

## CPC

- B24B 55/052: {with rotating tools}
- B24B 23/028: {Angle tools}
- B24B 27/08: being portable
- B24B 55/06: Dust extraction equipment on grinding or polishing machines (B24B31/12 takes precedence)
- B24B 55/102: {with rotating tools}
- B24B 31/12: Accessories; Protective equipment or safety devices; Installations for exhaustion of dust or for sound absorption specially adapted for machines covered by group B24B31/00 {(in general B24B55/00)}
- B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS

## Abstract

A dust hood (100), including a flange (90) for fastening the dust hood (100) to a transmission extension housing (210) of an angle grinder (200), and including a hood body (10) for covering a circular cutting wheel (220) on both sides, at least in sections, and including a suction connecting piece (40) for connecting a suction hose (400), via which removed substrate material (UG) may be extracted from the hood body (10), the dust hood (100) including a sensor unit (20), with the aid of which it is possible to detect whether the suction hose (20) is connected to the suction connecting piece (40) and/or whether a flap (45) of the suction connecting piece (40) is open.

## Claims

### Claim 1

A method for operating an angle grinder, the angle grinder including a cutting wheel and a dust hood equipped with a suction connecting piece, the method including the steps:
detecting whether a suction hose is connected to the suction connecting piece or whether a flap of the suction connecting piece is open with the aid of a sensor unit encompassed by the dust hood; and
controlling a rotational direction of the cutting wheel of the angle grinder as a function of the state detected by the sensor unit; wherein the sensor unit includes a flap contact to detect whether the flap is open or closed and a connecting piece contact to detect whether the suction hose is connected to the suction connecting piece; wherein the rotational direction includes a contra-rotating rotational direction corresponding to a dry cutting with dust extraction and a co-rotating direction corresponding to a dry cutting operation without dust extraction.

### Claim 2 (depends on 1)

The method as recited in claim 1 wherein if the flap is closed, the rotational direction is set to the contra-rotating rotational direction.

### Claim 3 (depends on 2)

The method as recited in claim 2 wherein if the flap is open, the rotational direction is set as a function of the connecting piece contact.

### Claim 4

A method for operating an angle grinder, the angle grinder including a cutting wheel and a dust hood equipped with a suction connecting piece, the method including the steps:
detecting whether a suction hose is connected to the suction connecting piece or whether a flap of the suction connecting piece is open with the aid of a sensor unit encompassed by the dust hood; and
controlling a rotational direction of the cutting wheel of the angle grinder as a function of the state detected by the sensor unit; wherein the sensor unit includes a flap contact to detect whether the flap is open or closed; wherein the rotational direction includes a contra-rotating rotational direction corresponding to a dry cutting with dust extraction and a co-rotating direction corresponding to a dry cutting operation without dust extraction.

### Claim 5 (depends on 4)

The method as recited in claim 4 wherein if the flap is open, the rotational direction is set to the contra-rotating rotational direction.

### Claim 6 (depends on 5)

The method as recited in claim 5 wherein if the flap is closed, the rotational direction is set to the co-rotating rotational direction.