EP3416780B1 - Angle grinder dust hood - Google Patents

Description

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 (see, for example US 2010/261417 A1 , which forms the basis for the preamble of claim 1). 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 retaining rail, that the retaining rail can be used either very cumbersome or not at all in the groove. 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.

From the US 2010/261417 A1 For example, a grinding tool with a grinding wheel mounted on the shaft of an engine is known. The abrasive tool includes a dust jacket having a depending flange extending about and around a circumference of the abrasive wheel, the dust jacket having a flattened segment and a peripheral flexible and adjustable region. An apron is attached to the flange and protrudes beyond it.

The WO2008 / 033377 A2 discloses a grinding tool. The grinding tool comprises a handle assembly having a support member and a head assembly including a grinding member that is rotatable relative to the handle assembly about a drive axis. The grinding tool also includes a pivot assembly that pivotally couples the head assembly to the support member of the handle assembly. The support member pivotally supports the pivot assembly, the drive axle extends through the pivot assembly, and the head assembly is pivotable about a plurality of different axes relative to the support member.

From the EP 2 186 600 A1 is a concrete grinder with a mounted in a transmission neck drive shaft known to which a concrete grinding wheel is loesbar connected and with a funnel-shaped suction hood, which covers the concrete grinding wheel and the edge overlaps with a guard ring. The suction hood is fastened in the region of a central opening for the gear neck by means of a holding device. The holding device has a height adjusting device with which the suction hood is guided in the axial direction of the drive shaft, directly or indirectly, with respect to the transmission neck height adjustable and fixable.

It is therefore an object of the present invention to provide an angle grinder dust hood, which ensures a holistic sealing between the dust hood and a surface to be machined of a workpiece.

The object is solved by the subject matter of independent claim 1.

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, wherein the first support rail extends along a closed circumference of the hood body.

According to the invention it is provided that 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, wherein the angle grinder dust hood has a circumferentially of the hood body along the hood body slidable hood segment, the need for gradual covering and releasing a remaining portion of the grinding wheel is provided, and wherein the circumference extends along a circular arc of the hood body and a chord of the hood segment, and wherein in the hood segment also a sealing member in the axial direction, based on the axis of rotation of the grinding wheel, is spring-loaded by at least one spring element ,

The solution according to the invention has the advantage that a near-wall grinding operation is made possible by means of the remaining part of the grinding wheel, which is not covered by the hood body. According to the invention is 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. Characterized in 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, a holistic or circumferential sealing is ensured.

Characterized in that the sealing element in the hood body in the axial direction, based on the axis of rotation of the grinding wheel, is spring-mounted by at least one spring element, a low tolerance with respect to the accuracy of fit of the retaining rail and optimal sealing can be ensured on the dust hood.

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 invention according to the invention feathered in hood body 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.

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 replacing 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, a groove is preferably formed, so that the hood body can be fixed positively 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.

Fig. 1

eine Draufsicht auf eine erfindungsgemäße Winkelschleifer-Staubhaube;

Fig. 2

eine erste schematische Unteransicht der erfindungsgemäßen Winkelschleifer-Staubhaube mit einem Federelement gemäß einer ersten Alternative;

Fig. 3

eine zweite schematische Unteransicht der erfindungsgemäßen Winkelschleifer-Staubhaube mit dem Federelement gemäß der ersten Alternative;

Fig. 4

eine dritte schematische Unteransicht der erfindungsgemäßen Winkelschleifer-Staubhaube mit dem Federelement gemäß der ersten Alternative;

Fig. 5

eine Schnittdarstellung entlang der Schnittlinie A - A in Fig. 1;

Fig. 6

eine perspektivische Ansicht eines Federelements gemäß einer ersten Alternative; und

Fig. 7

eine perspektivische Ansicht eines Federelements gemäß einer zweiten Alternative.

Show it:

Fig. 1

a plan view of an angle grinder dust hood according to the invention;

Fig. 2

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

Fig. 3

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

Fig. 4

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

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

Fig. 6

a perspective view of a spring element according to a first alternative; and

Fig. 7

a perspective view of a spring element according to a second alternative.

EXAMPLES

An inventive angle grinder dust hood 100 is in Fig. 1 shown 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 in Fig. 2 . 3 . 4 and 5 Shown both, the hood body 10 and the sliding 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 cover 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 in a first embodiment in Fig. 6 and in a second embodiment in FIG Fig. 7 shown isolated.

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 in Fig. 1 illustrated first embodiment, the spring element 50 via a pin (see FIG. Fig. 2 ) (eg hot-caulked), the pin engaging in a hole 52.

This in Fig. 7 illustrated 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 support rail 31 for the sealing element 30 extends along a closed circumference U to the hood body 10. The circumference U extends along a circular arc A of the hood body 10 and a chord D of the hood segment 20. In this way, the first support rail 31 is substantially a closed Circle with a straight side, namely the circular chord D of the hood segment 20. As in Fig. 2 and 4 can be seen, the sealing member 30 is for the hood body 10 only in the support rail 31 along the arc A of the hood body 10. The portion of the support rail 31 along the chord D of the hood segment 20 has no sealing member 30.

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 hood 100 is as in Fig. 4 shown in a closed state (ie, hood segment 20 is closed), closes the sealing member 30 for the hood segment 20, the portion of the support rail 31 along the chord D of the hood segment 20, which has no sealing member 30.

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. Im in Fig. 1 illustrated embodiment, the headband 55 protrudes in the axial direction from the bottom of the hood body 10 and instructs 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 rotation axis R, indicated by the double arrow M, for the purpose of replacing 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.

Again Fig. 1 can be removed, 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 protrude through the central opening 11. At the central opening 11, 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 REFERENCE NUMBERS

10

hood body

11

Central opening

12

groove

20

cap segment

30

sealing

31

first retaining rail of the hood body

31 '

second retaining rail of the hood segment

40

suction

50

spring element

51

base web

52

hole

53

swing arm

55

headband

57

stop web

100

Angle-dust cap

R

axis of rotation

U

scope

N

circumferentially

A

Circular arc of the hood body

B

Circular arc of the hood segment

D

Circular chord of the hood segment

Claims (11)

1. Angle grinder dust hood (100), with a hood body to cover a circular grinding wheel and with a sealing element (30) which can be positioned at least in sections in a first holding rail (31) and second holding rail (31') for the sealing at least in sections of the hood body (10) in relation to a surface which is to be processed by means of the grinding wheel, and with a suction connection (40), by means of which material removed from the surface can be extracted by suction out of the hood body (10), the first holding rail (31) running along a closed circumference (U) of the hood body (10),
   characterized in that the sealing element (30) is spring-mounted in the hood body (10), in the axial direction related to the axis of rotation (R) of the grinding wheel, by at least one spring element (50), wherein the angle grinder dust hood (100) comprises a hood segment (20) which can be displaced in the circumferential direction (N) of the hood body (20) along the hood body (10), and which is provided to allow for the gradual coverage and clearance of a remaining part of the grinding wheel as needed, and wherein the circumference (U) runs along a circle arc (A) of the hood body (10) and a chord (D) of the hood segment (20), and wherein, in the hood segment (20), there is likewise a sealing element (30), in the axial direction related to the axis of rotation of the grinding wheel, which is spring-mounted by at least one spring element (50).
2. Angle grinder dust hood (100) according to claim 1,
   characterized in that the spring element (50) comprises a base web (51), which is preferably configured as flat, by means of which the spring element (50) is secured to the hood body (10) and/or to the hood segment (20), preferably by means of a pin, a screw, or a rivet.
3. Angle grinder dust hood (100) according to claim 1,
   characterized in that the spring element (50) comprises at least one spring lever (53) projecting from the base web (51), wherein the orientation preferably corresponds to the outer circumference (U) of the hood body (10).
4. Angle grinder dust hood (100) according to any one of claims 1 to 3,
   characterized in that the hood body (10) comprises at least one holding bar (55) which is configured such as to prevent the sealing element (30) from falling in an axial direction out of the hood body (10) and/or out of the hood segment (20).
5. Angle grinder dust hood (100) according to claim 4,
   characterized in that the holding bar (55) is positioned with a first end (55a) at an underside of the hood body (10), and at a second end (55b) an axial stop is formed for the holding rail (31) of the sealing element (30), wherein the holding bar (55) can be deflected in the radial direction, related to the axis of rotation (R) of the grinding wheel, for the purpose of replacing the sealing element (30).
6. Angle grinder dust hood (100) according to claim 5,
   characterized in that the axial stop is configured as a stop web (57), which runs parallel to the base web (51) and preferably comprises a cut-out opening, such that a contact surface between the stop web (57) and the holding rail (31) is reduced.
7. Angle grinder dust hood (100) according to any one of the preceding claims, characterized in that the spring element (50) is formed as one piece, preferably from spring steel.
8. Angle grinder dust hood (100) according to any one of the preceding claims, characterized in that the spring element (50) comprises in the axial direction a spring rigidity which is less than a rigidity of the sealing element (30).
9. Angle grinder dust hood (100) according to any one of the preceding claims, characterized in that a plurality of spring elements (50) are provided along the circumference of the hood body (10) and/or of the hood segment (20).
10. Angle grinder dust hood (100) according to any one of the preceding claims,
    characterized in that the hood body (10) comprises a central opening (11), through which a drive spindle can project, to which the circular grinding wheel is to be attached, such that the hood body (10) can be secured in positive fit and therefore securely fixed to an angle grinder.
11. Angle grinder with an angle grinder dust hood (100) according to any one of the preceding claims, wherein the hood body (10) is arranged securely fixed to the angle grinder.

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