US20070246583A1

US20070246583A1 - Water Supply for Angle Gringder

Info

Publication number: US20070246583A1
Application number: US11/577,409
Authority: US
Inventors: Ernst Gorenflo
Original assignee: Dolmar GmbH
Current assignee: Makita Engineering Germany GmbH
Priority date: 2004-10-20
Filing date: 2005-10-18
Publication date: 2007-10-25
Also published as: DE202004016268U1; CN101043993A; WO2006042523A1

Abstract

The invention relates to a cutting device arrangement including a generator and a spray device in the region of a cutting tool whereby liquid is sprayed for binding cutting residue blown up during the cutting process. The cutting device also includes a liquid supply device whereby the liquid can be supplied to the spray device. An electric pump is provided as part of the spray device whereby the liquid can be sprayed under pressure, wherein the electric pump is electrically connected to the generator.

Description

FIELD OF INVENTION

The invention relates to a cutting device arrangement comprising a generator and a spray device comprising at least one spray means in the region of a cutting tool whereby liquid is sprayed for binding cutting residue blown up during the cutting process, and comprising a liquid supply device whereby the liquid can be supplied to the spray means.

BACKGROUND

Generic cutting device arrangements for cutting and cutting to length of, for example, natural or artificial cement stone slabs, corrugated sheets or profiles, in the form of angle grinders have long been known. The cutting residue swirled up during the cutting process, which can have consequences harmful to health, particularly in the form of blown-up dust, is bound by water sprayed onto the cutting disk of the angle grinder by means of a spray device according to the prior art. In this case, the water is pressed through a supply hose and the spray nozzles in the form of falling water or pressurised water.
A disadvantage with the known spraying systems, in particular for angle grinders, is also that the water sprayed onto the cutting disk only emerges from the spray nozzles at low pressure.
WO 02/47873 A1 discloses an angle grinder having a mechanical pump in its cutting arm which can be used to pump out water from a bucket. The mechanical pump is connected to the drive via a crankshaft. This document is selected as the nearest prior art.
Known from WO 00/05032 are spray devices for hand-held joint cutters with an electrical water pump which is supplied with power by a fixed mains connection. However, such joint cutters are locally restricted in their use to the area around a plug socket.
It is thus the object of the present invention to provide a cutting device arrangement with a spray device which efficiently binds dust.

SUMMARY OF THE INVENTION

The object is achieved by a cutting device arrangement specified initially comprising an electric pump provided as part of the spray device, whereby liquid can be sprayed under pressure from the spray means and which is electrically connected to the generator.
The spray device according to the invention comprises an electrically operated pump which ejects liquid, preferably water, under pressure, preferably from a spray nozzle, preferably in the direction of the cutting disk and the cutting region. As a result of the higher pressure of the liquid before its exit from the spray means compared with the prior art, the liquid is more finely atomised and binds the blown-up cutting residue, in particular dust, more efficiently and more rapidly during operation.
The electric pump advantageously has a regulating means for regulating the liquid flow through the liquid supply device. In this case, the rotational speed of the electric pump can be regulated, for example, by a potentiometer. It is also possible to provide the electric pump with an on/off switch which renders a stopcock as conventionally used superfluous. In one embodiment of the invention, the cutting device arrangement has a pressure regulating valve for the liquid to be sprayed. Said devices allow precise adjustment of the spray device to the respective conditions.
In a particularly preferred embodiment of the invention, the cutting device arrangement comprises an angle grinder in which the generator is located. The generator can be driven by an internal combustion engine which drives a cutting disk of the angle grinder. The cutting device arrangement according to the invention preferably has no mains power connection. The electric pump is thus independent of a fixed mains connection. The entire cutting device arrangement generates the current required by the electric pump itself and is autonomous in this respect.
The invention is particularly suitable in connection with angle grinders which already have a spray device according to the prior art, e.g. in the form of a liquid tank with outgoing hose mounted on an angle grinder carriage in the floor area. According to the invention, the liquid supply device already provided can be expanded and improved by installing an electric pump, for example, directly at the outlet of the liquid tank. The pump increases the pressure produced hitherto merely by the height difference from the liquid tank and spray means due to the falling liquid. The electric pump is supplied with power via an externally accessible power connection at the angle grinder.
The power cable of the electric pump can initially be guided along a section of the hose of the liquid supply on the outside and leave the hose in the area of the current connection of the angle grinder. In this case, power cable and hose can be welded together, e.g. by vulcanising the cable onto the hose or they can also be laid parallel to one another.
It is also feasible to expand a conventional pressurised liquid tank according to the invention by arranging the electric pump at the outlet of the pressurised liquid tank or at the end of a hose connected to the outlet of the pressurised liquid tank. The relevant angle grinder has a liquid connecting piece in this case and an electric connection for the electric pump.
The electric pump located outside the angle grinder has the advantage that the angle grinder itself is light and is thus convenient to handle during operation when a spraying device can be dispensed with.
The water pump can also be integrated directly in the angle grinder. Then, the angle grinder requires no external power connection. In this embodiment, the angle grinder only requires a connection for a hose of the liquid supply device.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described with reference to three exemplary embodiments in the figures. In this case, in the figures:
FIG. 1 is an arrangement of an angle grinder according to the invention on a guide carriage in a first embodiment,
FIG. 2 is an angle grinder according to the invention with integrated water pump according to a second embodiment,
FIG. 3 is an arrangement of an angle grinder according to the invention with an external water container and water pump.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The cutting device arrangement shown in FIG. 1 comprises an angle grinder 1 which is locked in position on the bottom of a guide carriage 2. A water tank 3 is located on the guide carriage 2 above the angle grinder 1 adjacent to a handle 4 provided for a user to move the arrangement. The angle grinder 1 has a cutting disk 6 in the advancing region which is approximately half-covered on both sides by a protective hood 7. Each of the sides of the protective hood 7 is provided with two openings which pass through the hood walls in the advancing region, each having a water nozzle 8 inserted therein. The right-hand water nozzle 8 in the direction of advance of the arrangement is connected via a hose 9 to an electric water pump 11 which in turn is inserted directly at the bottom end of the water tank 3 in an opening provided for this purpose. The two water nozzles 8 are interconnected in a water-conducting manner by means of a PU hose 9 guided externally around the protective hood 7.
The cutting disk 6 is driven by a two-stroke internal combustion engine which also drives a generator (not shown) for power generation which is required for ignition, among other things. The generator supplies a current connection 12 provided on an outer wall of the angle grinder 1. The current connection 12 is intended for supplying the electric water pump 11. A power cable 13 provided for supplying current to the electric water pump 11 is guided next to a section of the PU hose 9 adjacent to the water container 3 away from the PU hose 9 in the area of the current connection 12.
The electric water pump 11 makes it possible to eject the water provided in the water container 3 under pressure through the PU hose 9 and finely atomised and nebulised by the nozzle arrangement onto the cutting disk 6 and spray the cutting residue separated during operation by the cutting disk 7 out from the bottom. The moisture binds the cutting residue, in particular the fine dust. The electric pump is provided with a potentiometer (not shown) which regulates the water flow through the PU hose 9. In addition, the electric water pump can be switched by means of an on/off switch. The pressure of the water in the PU hose can be adjusted by the user by means of a pressure regulating valve.
In the second embodiment of the invention, manual operation of the angle grinder 1 is provided. In the second embodiment, the angle grinder 1 has an integrated electric water pump 11. In this case, the electric water pump 11 is integrated in the device. It can be built into an arm 16 which is arranged laterally in the cutting direction and which connects a drive unit to a handle unit. The electric water pump 11 is supplied with current on the one hand by the generator (not shown) provided in the angle grinder 1 by means of a power cable which runs completely inside the angle grinder. The generator is driven exclusively by the internal combustion engine of the angle grinder. From the electric water pump 11, a PU hose 9 runs on the one hand to the water nozzles 8 which are arranged according to the first embodiment (FIG. 1) in the protective hood 7. On the other hand, a PU hose 9 runs from the electric water pump to an external water connection 17. A conventional liquid tank as shown in FIG. 1 or FIG. 3, for example, can be connected to the external water connection 17 via a PU hose (not shown).
In the third embodiment of the invention, the electric water pump 11 is again located outside the angle grinder 1, The angle grinder 1 has an external current connection 12 which is supplied with current by the generator of the angle grinder 1. A power cable 13 can be connected to the plug of the electric water pump 11 at the current connection 12. In this embodiment, the water container 3 is connected via a PU hose 9 to an electric water pump 11 arranged separately from the angle grinder 1. A second PU hose 9 runs from the electric water pump 11. In addition to the externally accessible power connection 12, the angle grinder 1 has a water connection 17 for the second PU hose 9 of the water pump 1.

Claims

1. A cutting device arrangement comprising a hand-held angle grinder (1) and a spray device (3, 8, 9) comprising at least one spray means (8) in the region of a cutting tool (6) whereby liquid is sprayed for binding cutting residue blown up during the cutting process, and comprising a liquid supply device (3, 9) whereby the liquid can be supplied to the spray means (8), characterised by a generator driven by an internal combustion engine, arranged in the hand-held angle grinder (1) and by an electric pump (11) provided as part of the spray device (3, 8, 9) whereby the liquid can be sprayed under pressure from the spray means (8) and which is electrically connected to the generator.

2. The cutting device arrangement according to claim 1, characterised in that the electric pump (11) has a regulating means for regulating water flow.

3. The cutting device arrangement according to claim 1, characterised in that the electric pump (11) has an on and off switch.

4. The cutting device arrangement according to claim 1, characterised in that a pressure regulating valve regulates the pressure of the sprayed liquid.

5. The cutting device arrangement according to claim 1, characterised in that the generator is driven by an internal combustion engine of the angle grinder (1).

6. The cutting device arrangement according to claim 1, characterised in that the liquid supply device (3, 9) comprises a liquid tank (3) and at least one hose (9) for the liquid supply.

7. The cutting device arrangement according to claim 1, characterised by a protective hood (7) which partially surrounds the cutting tool (6) through the side wall whereof the at least one spray means (8) is guided.

8. The cutting device arrangement according to claim 1, characterised in that the electric pump (11) can be connected detachably to the angle grinder (1).

9. The cutting device arrangement according to claim 1, characterised in that the angle grinder (1) has an externally accessible power connection (12) for the electric pump (11).

10. The cutting device arrangement according to claim 9, characterised by a guide carriage (2) on which the angle grinder (1) can be locked in position and by a power cable (13) for the electric pump (11) which is guided externally along a section of a hose (9) of the liquid supply device (3, 9) and which leaves the hose (9) in the region of the power connection (12).

11. The cutting device arrangement according to claim 9, characterised in that the electric pump (11) is arranged directly on a water tank (3).

12. The cutting device arrangement according to claim 1, characterised in that the electric water pump (11) is built into the angle grinder (1).

13. The cutting device arrangement according to claim 12, characterised in that the electric water pump (11) is built into an arm (16) which connects a drive unit to a handle unit.

14. The cutting device arrangement according to claim 5, characterised in that the angle grinder (1) has an externally accessible connecting piece (17) for a hose (9) of the liquid supply device (3, 9).