WO2017140655A1

WO2017140655A1 - Dust collector for angle grinder

Info

Publication number: WO2017140655A1
Application number: PCT/EP2017/053240
Authority: WO
Inventors: Sarah HARDER; Konstantin Baxivanelis
Original assignee: Hilti Aktiengesellschaft
Priority date: 2016-02-17
Filing date: 2017-02-14
Publication date: 2017-08-24
Also published as: EP3416780A1; US20190039207A1; CN108698200B; CN108698200A; EP3208040A1; EP3416780B1

Abstract

A dust collector for an angle grinder comprises a collector body for covering a circular grinding disk, a sealing element for sealing at least some sections of the collector body from a surface to be machined by the grinding disk, at least some sections of the sealing element being placeable in a first and a second retaining rail, and a suction terminal via which the abraded surface particles can be sucked off the collector body. The first retaining rail extends along a closed periphery of the collector body, and in the collector body, the sealing element is spring-mounted by at least one spring element in the axial direction relative to the axis of rotation of the grinding disk.

Description

"Angle grinder dust hood"

The present invention relates to an angle grinder dust hood with a hood body for covering a circular grinding wheel and with a at least partially positionable in a first holding rail and second holding rail sealing element for at least partially sealing the hood body relative to a surface to be machined by means of the grinding wheel, and with a suction via a surface removal can be sucked out of the hood body. The sealing element may be, for example, a brush curtain, slats or the like.

Angle grinder dust hoods of the type mentioned are basically known from the prior art. They are used to prevent dust spreading during grinding work to protect the health of a user of the angle grinder.

It is known to provide the hood body with a sealing element, for example a circumferential brush curtain or with a plurality of brushes, so that the hood body terminates on the surface to be machined of a workpiece.

Moreover, it is also possible that the sealing element is a single single elastic element or several individual elastic elements. The elastic member may be a foam, an elastomer (e.g., rubber, rubber, etc.) or the like.

If the angle grinder is placed slightly obliquely on the surface of the workpiece to be machined, then the sealing element can compensate a gap which may arise between the hood body and the surface of the workpiece to be machined. The sealing element is fastened in a holding rail, which in turn is positioned on the underside of the dust hood, ie the side of the dust hood facing the grinding wheel. Usually, the retaining rail is clamped in a correspondingly formed groove on the dust hood. To change a worn sealing element, the entire holding rail with the attached sealing element is practically pulled out of the groove on the underside of the dust hood and clamped a new retaining rail together with a new sealing element in the groove. According to the prior art, the retaining rails are designed in the form of an open circle or arc for this purpose. As a result, the retaining rail is flexible and malleable, so that it can be relatively quickly and effectively brought out and back into the groove on the guard.

However, the designed in the form of an open circle or arc retaining rail according to the prior art has the disadvantage that the diameter of the retaining rail has the manufacturing process owed large tolerances, which significantly deteriorates the accuracy of fit of the retaining rail in the groove of the dust hood. So it can happen with a too large diameter of the support rail that the support rail can either be very cumbersome or not inserted into the groove either. On the other hand, a holding rail with a diameter that is too small is not able to properly seal the entire circumference of the dust hood.

It is therefore an object of the present invention to provide an angle grinder dust hood, which eliminates the disadvantages described above and in particular to ensure an optimal seal between the dust hood and a surface to be machined of a workpiece.

The object is solved by the subject matter of independent claims 1 and 13. Advantageous embodiments of the present invention can be found in the subclaims.

An angle grinder dust hood is therefore provided with a hood body for covering a circular grinding wheel and with a sealing element which can be positioned at least in sections in a first holding rail and second holding rail for at least partially sealing the hood body with respect to a surface to be machined by means of the grinding wheel, and with a suction connection a surface removal can be sucked out of the hood body.

According to the invention it is provided that the first retaining rail extends along a closed circumference of the hood body and the sealing element in the hood body in the axial direction, based on the axis of rotation of the grinding wheel, is spring-loaded by at least one spring element. As a result, a low tolerance with respect to the accuracy of fit of the retaining rail and optimum sealing on the dust hood can be ensured.

The invention includes the recognition that, in particular in an overhead operation of an angle grinder, a hood body with according to the prior art rigidly attached thereto brush curtain is pulled by gravity and a possibly connected to the suction suction hose down. Thus, disadvantageously, a gap between the brush curtain and the surface to be processed arise. By the According to the invention in the hood body spring-mounted brush curtain of the brush curtain is always pressed to the machined surface, whereby a gap is avoided or at least substantially reduced.

The invention also includes the recognition that a worn brush curtain may typically have a high stiffness with respect to the axial direction, so that a lot of force has to be expended on the grinding wheel against the stiffness of the worn brush curtain on the surface of the brush to be machined To bring workpiece. This is because with angle grinder dust hoods of the prior art, as already mentioned, the brush curtain is rigidly attached to the hood body.

In addition, the present invention includes the knowledge that an already heavily worn pad, in particular a diamond pot, is used in conjunction with a new angle grinder dust hood and the user disadvantageously against the relatively high stiffness of the still stiff brush curtain the new angle grinder dust hood already flattened sanding pad must press on the surface to be machined of the workpiece. A worn pad often has a lower height, i. a less concave shape than a new or unused sanding pad.

In the angle grinder dust hood according to the invention, the spring element takes over the axial movement of the sealing element with respect to the hood body. Any radial displacements can continue to be compensated by the sealing element itself. In the context of the invention is intended to be understood by a spring element is a preferably discrete spring element and not merely a possible spring action or resilience of the brush curtain in the axial direction.

In addition, the invention includes the recognition that angle grinder dust hoods of the prior art to achieve the spring action of the invention can not be developed such that a spring element is provided approximately between hood body and angle grinder housing. This would have in overhead work the disadvantage that the weight of a suction hose connected to the suction would compress such a spring in an undesirable manner.

In a particularly preferred embodiment of the present invention can be provided that the angle grinder dust hood has a circumferentially of the hood body along the hood body slidable hood segment, which provided for the needs of gradually covering and releasing a remaining portion of the grinding wheel and wherein the circumference extends along a circular arc of the hood body and a chord of the hood segment. This allows a near-wall grinding operation by means of the remaining part of the grinding wheel, which is not covered by the hood body. Preferably, in the hood segment also a sealing element in the axial direction, based on the axis of rotation of the grinding wheel, spring-mounted by at least one spring element.

In order to ensure a holistic or circumferential sealing, it can be provided according to a further advantageous embodiment of the present invention that in the hood segment also a sealing member in the axial direction, based on the axis of rotation of the grinding wheel, is spring-mounted by at least one spring element.

It has proven to be advantageous if the spring element has a preferably flat base web. About the base bar, the spring element may be attached to the hood body and / or the hood segment. Preferably, fastening takes place by means of a pin, a screw and / or a rivet. In addition, it can also be provided that the spring element is mounted directly in the hood body by means of a spring clip via an undercut. The spring clip can also be referred to as a clip, so that the spring element is clipped into the hood body. Furthermore, the spring element can also be injected directly into the hood body or into the hood housing. In the base web preferably at least one hole is provided, into which a pin, a screw or a rivet can engage.

Alternatively, it could also be provided that the spring element is attached to the first and / or second retaining rail for the sealing element.

Preferably, the spring element or the spring elements are arranged within a volume defined by the hood body or hood segment. Preferably, the hood body and / or the hood segment has a housing section whose curvature corresponds to the curvature of the grinding wheel. Preferably, the spring element is arranged in the immediate vicinity of this section. Preferably, the spring element is arranged as far as possible from a rotation axis of the grinding wheel within the hood body volume or the hood segment volume.

It has proved to be advantageous if the spring element has at least one spring rocker protruding from the base web. Preferably, the spring element is mounted such that the orientation of the projecting spring wings preferably corresponds approximately to the outer periphery of the hood body.

According to a further embodiment, it could also be provided that the spring element is also arranged radially. Alternatively, it can also be provided that the spring element has two spring wings projecting from the base web. In this way, a higher stability of the spring element in an assembled state and an increased spring force can be achieved.

When the spring element is mounted, the spring wings form a tangent to the circular grinding wheel or to the oval body of the grinding hood.

In a particularly preferred embodiment, the spring element has at least one retaining clip, which is designed to prevent an axial falling out of the sealing element from the hood body and / or the hood segment.

According to a further advantageous embodiment it can be provided that the headband is positioned with a first end on an underside of the hood body and an axial stop for the retaining rail of the sealing element is formed at a second end, wherein the headband in the radial direction, based on the axis of rotation the grinding wheel, for the purpose of Auswechseins the sealing element is deflectable.

Further advantageously, the axial stop may be formed as a stop web, which preferably extends parallel to the base web. Advantageously, the stop formed as an axial stop has a recess, so that a contact surface between the stop web and sealing element or retaining rail of the brush curtain is reduced. The recess preferably requires a saving of material and a low surface for dust. In addition, a friction surface is reduced with respect to the brush curtain, so that it can be moved easily in the axial direction.

It has proved to be advantageous if the spring element is formed in one piece, preferably made of spring steel. Particularly preferably, the spring element in the axial direction on a spring stiffness, which is less than a stiffness of the brush curtain covered brushes. Alternatively, the spring element can also be designed in several parts.

Particularly preferably, a plurality of spring elements along the circumference of the hood body and / or the hood segment is provided. It has proven to be advantageous if an angle grinder dust hood, which has a hood body and a hood segment, is equipped with five preferably evenly spaced spring elements.

In a further preferred embodiment, the hood body has a central opening through which a drive spindle, to which the circular grinding wheel is to be attached for grinding operation, can project through the central opening. At the central opening is Preferably, a groove formed so that the hood body can be positively secured and thus fixed to the frame on an angle grinder.

The object is also achieved by an angle grinder with an angle grinder dust hood of the type described above, wherein the hood body is fixed to the frame arranged on the angle grinder or can be arranged.

Further advantages will become apparent from the following description of the figures. In the figures, various embodiments of the present invention are shown. The figures, the description and the claims contain numerous features in combination. The skilled person will conveniently consider the features individually and summarize meaningful further combinations.

In the figures, identical and similar components are numbered with the same reference numerals. Show it:

Fig. 1 is a plan view of an angle grinder dust hood according to the invention;

2 shows a first schematic bottom view of the angle grinder dust hood according to the invention with a spring element according to a first alternative;

3 is a second schematic bottom view of the angle grinder according to the invention

Dust hood with the spring element according to the first alternative;

4 shows a third schematic bottom view of the angle grinder dust hood according to the invention with the spring element according to the first alternative;

Fig. 5 is a sectional view along the section line A - A in Fig. 1;

6 shows a perspective view of a spring element according to a first alternative;

and

Fig. 7 is a perspective view of a spring element according to a second alternative.

EXAMPLES

An inventive angle grinder dust hood 100 is shown in Fig. 1 in a plan view.

The angle grinder dust hood 100 has a hood body 10 for covering a circular grinding wheel not shown in the figures. An axis of rotation R of the grinding wheel is indicated by a dot-dash line. The angle grinder dust hood 100 likewise has a hood segment 20 which is displaceable along a circumferential direction N of the hood body 10 along the hood body 10.

The hood body 10 is configured to cover a majority of the grinding wheel, with the sliding hood segment 20 being provided for covering and releasing a remaining portion of the grinding wheel.

As shown in Figs. 2, 3, 4 and 5, both the hood body 10 and the slidable hood segment 20 each have a sealing member 30 in the form of a brush curtain. As described in detail below, the sealing element 30 is positioned in a first retaining rail 31 and in a second retaining rail 31 '.

Since the angle grinder dust hood 100 of FIG. 1 has both a hood body 10 and a hood segment 20, the brush curtain 30 is formed in two parts or two brush curtains are provided. The designed as a brush curtain sealing member 30 for the hood body 10 is clamped or positioned in the first retaining rail 31. Furthermore, the sealing element 30 designed as a brush curtain for the hood segment 20 is clamped or positioned in the second retaining rail 31 '.

The brush curtains 30 serve to seal the hood body 10 and the hood segment 20 to a machined surface of a material, which is not shown here. A surface removal in the course of processing (for example grinding work) can be sucked off via a suction connection 40 provided on the hood body 10.

The brush curtain 30 is spring-loaded with respect to the hood body 10 and the hood segment 20 in the axial direction, relative to the axis of rotation R of the grinding wheel, by a spring element 50. The spring element 50 is shown isolated in a first embodiment in Fig. 6 and in a second embodiment in Fig. 7. In the first and second exemplary embodiments, the spring element 50 has a flat base web 51, by way of which the spring element 50 is fastened to the hood body or hood segment 20.

In the first embodiment shown in Fig. 1, the spring member 50 is secured (e.g., hot staked) by a pin (see Fig. 2), which pin engages a hole 52.

The illustrated in Fig. 7 second embodiment of the spring element 50 substantially corresponds to the first embodiment. In contrast to the first embodiment, the base web 51 has no hole.

Both in the first and in the second embodiment, the spring element 50 has two projecting from the base web 51 in opposite directions spring wings 53. The spring wings 53 each exert a spring action on a retaining rail 31 of the brush curtain 30. The spring wings 53 are oriented with the spring element 50 mounted in the direction of the outer circumferential direction N of the hood body 10.

The first retaining rail 31 for the sealing element 30 extends along a closed circumference U around the hood body 10. The circumference U extends along one

Circular arc A of the hood body 10 and a circular chord D of the hood segment 20.

As a result, the first retaining rail 31 essentially forms a closed circle with a straight side, namely the circular chord D of the hood segment 20. As can be seen in FIGS. 2 and 4, the sealing element 30 for the hood body 10 is located only in the retaining rail 31 along the circular arc A of the hood body 10. The section of

Retaining rail 31 along the chord D of the hood segment 20 has no sealing element

30 on.

The retaining rail 31 'for receiving the sealing member 30 for the hood segment 20 extends along the circular arc B of the hood segment 20 and the chord D of the hood segment 20. The sealing member 30 is located only in the portion of the support rail 31' along the arc B of the hood segment 20th ,

When the angle grinder dust hood 100 is in a closed state (ie hood segment 20 closed) as shown in FIG. 4, the sealing member 30 for the hood segment 20 closes the portion of the retaining rail 31 along the chord D of the hood segment 20 that does not have a sealing member 30 having.

The hood body 10 and the hood segment 20 have retaining clips 55 which are designed to prevent an axial fall-out of the brush curtain 30 from the hood body 10 or the hood segment 20. In the embodiment shown in FIG. 1, the retaining bracket 55 protrudes in the axial direction from the underside of the hood body 10 and has its free end a stop for the retaining rail 31, 31 'of the brush curtain 30 on. The axial stop is presently designed as a stop web 57 which extends substantially parallel to the hood body 10.

The retaining bracket 55 is deflectable in the radial direction to the axis of rotation R, indicated by the double arrow M, for Auswechseins the brush curtain. Thus, advantageously configured as a brush curtain sealing member 30 can be replaced without a special tool is required for it.

By the spring element 50, a functional integration is realized, namely on the one hand, the spring action in the axial direction, on the other hand falling out of the brush curtain 30 from the hood body 10 and the hood segment 20 is prevented.

As can be seen in FIG. 1, the hood body 10 has a central opening 11 through which a drive spindle, not shown here, to which the circular grinding wheel is to be attached, can project through the central opening 11. At the central opening 1 1, a groove 12 is formed so that the hood body 10 can be positively secured and thus fixed to a frame fixed to an angle grinder, not shown.

The arranged within a volume of the hood body 10 on the outer edge of the hood body 10 spring elements 50 exert by their respective spring wings 53 a spring action on the support rail 31 of the brush curtain 30.

LIST OF REFERENCES

10 hood body

1 1 Central opening

12 groove

20 hood segment

30 sealing element

31 first retaining rail of the hood body 31 'second retaining rail of the hood segment 40 suction connection

50 spring element

51 base bar

52 holes

53 spring rocker

55 retaining bracket

57 stop bridge

100 angle grinder dust hood

R rotation axis

U circumference

N circumferential direction

A circular arc of the hood body

B Circular arc of the hood segment

D Circle chord of the hood segment

Claims

claims

Angle grinder dust hood (100) having a hood body (10) for covering a circular grinding wheel and having a sealing element (30) which can be positioned at least in sections in a first retaining rail (31) and second retaining rail (31 ') for at least partially sealing the hood body (10) with respect to a surface to be machined by means of the grinding wheel, and with a suction connection (40) through which a surface removal from the hood body (10) can be sucked off,

characterized in that the first retaining rail (31) along a closed circumference (U) of the hood body (10) and the sealing member (30) in the hood body (10) in the axial direction, based on the axis of rotation (R) of the grinding wheel, by at least a spring element (50) is spring-loaded.

Angle grinder dust hood (100) according to claim 1,

characterized in that the angle grinder dust hood (100) has a hood segment (20) displaceable in the circumferential direction (N) of the hood body (10) along the hood body (10), which is provided for gradually covering and releasing a remaining portion of the grinding wheel as required; and wherein the circumference (U) extends along a circular arc (A) of the hood body (10) and a chord (D) of the hood segment (20).

Angle grinder dust hood (100) according to claim 2,

characterized in that in the hood segment (20) also a sealing element (30) in the axial direction, based on the axis of rotation of the grinding wheel, by at least one spring element (50) is spring-mounted.

Angle grinder dust hood (100) according to at least one of claims 1 to 3,

characterized in that the spring element (50) has a preferably flat base web (51) via which the spring element (50) on the hood body (10) and / or the hood segment (20) is fixed, preferably by means of a pin, a screw or a rivet.

5. angle grinder dust hood (100) according to claim 4,

characterized in that the spring element (50) has at least one of the base web (51) projecting spring rocker (53), wherein the orientation preferably corresponds to the outer circumference (U) of the hood body (10).

6. angle grinder dust hood (100) according to at least one of claims 3 to 5,

characterized in that the hood body (10) has at least one retaining bracket (55) which is designed to prevent an axial falling out of the sealing element (30) from the hood body (10) and / or the hood segment (20).

7. angle grinder dust hood (100) according to claim 6,

characterized in that the headband (55) is provided with a first end (55a) on a

Bottom of the hood body (10) is positioned and at a second end (55 b) an axial stop for the retaining rail (31) of the sealing element (30) is formed, wherein the headband (55) in the radial direction, relative to the axis of rotation (R) the grinding wheel, for the purpose of Auswechseins the sealing element (30) is deflectable.

8. angle grinder dust hood (100) according to claim 7,

characterized in that the axial stop is formed as a stop web (57) which extends parallel to the base web (51) and preferably has a recess, so that a contact surface between the stop web (57) and the retaining rail (31) is reduced.

9. angle grinder dust hood (100) according to one of the preceding claims,

characterized in that the spring element (50) is integrally formed, preferably made of spring steel.

10. angle grinder dust hood (100) according to at least one of the preceding claims, characterized in that the spring element (50) in the axial direction has a spring stiffness, which is less than a stiffness of the sealing element (30).

1 1. Angle grinder dust hood (100) according to at least one of the preceding claims, characterized in that a plurality of spring elements (50) along the circumference of the hood body and / or the hood segment is provided.

12. angle grinder dust hood (100) according to at least one of the preceding claims, characterized in that the hood body (10) has a central opening (1 1) through which a drive spindle, to which the circular grinding wheel is to be attached, project through at the central opening (1 1) a groove (12) is formed, so that the hood body (10) can be fixed positively and thus fixed to a frame on an angle grinder.

13. angle grinder with an angle grinder dust cover (100) according to at least one of the preceding claims, wherein the hood body (10) is arranged fixed to the frame fixed to the angle grinder or can be arranged.