US20190039207A1

US20190039207A1 - Dust collector for angle grinder

Info

Publication number: US20190039207A1
Application number: US16/075,718
Authority: US
Inventors: Sarah HARDER; Konstantin Baxivanelis
Original assignee: Hilti AG
Current assignee: Hilti AG
Priority date: 2016-02-17
Filing date: 2017-02-14
Publication date: 2019-02-07
Also published as: CN108698200B; EP3416780B1; WO2017140655A1; EP3208040A1; EP3416780A1; CN108698200A

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

The present invention relates to a dust collector for an angle grinder, having a collector body for covering a circular grinding disk, having 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 having a suction terminal via which the abraded surface particles can be sucked out of the collector body. The sealing element can be, for example, a brush curtain, fins, or the like.
Dust collectors for angle grinders of the type mentioned are generally known in the prior art. They are used to prevent the spread of dust during grinding work, to protect the health of a user of the angle grinder.
A known approach equips the collector body with a sealing element, for example a circumferential brush curtain or a plurality of brushes, such that the collector body closes with the surface of a workpiece being machined.
Moreover, it is also possible for the sealing element to be a single, separate elastic element or several separate elastic elements. The elastic element may be a foam, an elastomer (such as rubber, etc.), or the like.
If the angle grinder is placed slightly obliquely on the surface of the workpiece being machined, the sealing element can provide a compensatory seal for a gap which may arise between the collector body and the surface of the workpiece being machined. The sealing element is fastened in a holding rail in this case, which in turn is positioned on the underside of the dust collector—that is, the side of the dust collector facing the grinding wheel. Typically, the retaining rail is clamped in a correspondingly formed groove on the dust collector. To change a worn sealing element, the entire holding rail with the sealing element fastened thereon is expediently pulled out of the groove on the underside of the dust collector, and a new retaining rail is clamped, together with a new sealing element, into the groove. According to the prior art, the retaining rails are designed in the form of an open circle and/or arc for this purpose. As a result, the retaining rail is flexible and moldable, such that it can be relatively quickly and effectively brought out and back into the groove of the protective cover.
However, the retaining rail according to the prior art, designed in the form of an open circle or arc, has the disadvantage that the diameter of the retaining rail has large tolerances as a result of the manufacturing process, which significantly compromises the accuracy of fit of the retaining rail in the groove of the dust collector. As a result, if the diameter of the retaining rail is too large, the retaining rail can only be inserted into the groove either with great effort or not at all. 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 collector.
It is therefore the object of the present invention to provide a dust collector for angle grinders which eliminates the disadvantages described above, and in particular to ensure an optimum sealing between the dust collector and a surface of a workpiece being machined.
This object is achieved by the subject matter of independent claims 1 and 13. Advantageous embodiments of the present invention can be found in the dependent claims.
A dust collector for angle grinders is accordingly provided which has 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 out of the collector body.
According to the invention, the first retaining rail extends along a closed circumference of the collector body, and in the collector body the sealing element is spring-loaded by at least one spring element in the axial direction relative to the axis of rotation of the grinding disk. This ensures tight tolerance with respect to the accuracy of fit of the retaining rail, and optimum sealing on the dust collector.
The invention includes the realization that, in particular when an angle grinder is used overhead, a collector body with a brush curtain according to the prior art which is rigidly attached thereto, and any suction hose connected to the suction terminal, are pulled downward by gravity. Thus, disadvantageously, a gap forms between the brush curtain and the surface being machined. Due to the brush curtain spring-loaded in the collector body according to the invention, the brush curtain is always pressed against the surface being machined, such that a gap is prevented, or at least substantially reduced.
The invention also includes in this regard the recognition that a worn brush curtain can typically be highly stiff with respect to the axial direction, such that, disadvantageously, a great deal of force has to be applied to bring the grinding wheel against the surface of the workpiece being machined, while opposing the stiffness of the worn brush curtain. This is because, in dust collectors for angle grinders according to the prior art, as already mentioned, the brush curtain is rigidly attached to the collector body.
In addition, the present invention includes the recognition that an already-heavily worn grinding disk, in particular a diamond cup grinder, is used with a new angle grinder dust collector, and the user disadvantageously must press, against the relatively high stiffness of the still-stiff brush curtain of the new angle grinder dust collector, the already-flattened grinding disk onto the surface of the workpiece being machined. A worn grinding disk often has a lower height—that is, a less concave shape—than a new or unused grinding disk.
In the dust collector for angle grinders according to the invention, the spring element assumes the axial movement of the sealing element relative to the collector body. Any radial displacement can continue to be compensated by the sealing element itself. In the context of the invention, a ‘spring element’ is preferably used to mean a 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 dust collectors for angle grinders of the prior art cannot be advanced in such a manner that, to achieve the spring action according to the invention, a spring element is provided approximately between the collector body and angle grinder housing. This would have the disadvantage in overhead work that the weight of a suction hose connected to the suction terminal would compress such a spring in an undesirable manner.
In a particularly preferred embodiment of the present invention, the angle grinder dust collector can have a collector segment which can be displaced in the circumferential direction of the collector body along the collector body, provided for gradually covering and uncovering a remaining portion of the grinding disk as required, wherein the circumference runs along a circular arc of the collector body and a chord of the collector segment. This enables grinding operation close to a wall by means of the remaining part of the grinding disk which is not covered by the collector body. Preferably, a sealing element is likewise spring-loaded in the collector segment by at least one spring element in the axial direction, based on the axis of rotation of the grinding disk.
In order to ensure a uniform and/or circumferential sealing, according to a further advantageous embodiment of the present invention, a sealing element can also be spring-loaded by at least one spring element in the collector segment in the axial direction, based on the axis of rotation of the grinding disk.
It has proved to be advantageous if the spring element has a preferably flat base web. The spring element can be attached to the collector body and/or to the collector segment on the base web. Preferably, the attachment is made by means of a pin, a screw, and/or a rivet. In addition, the spring element can also be attached directly in the collector body via an undercut, by means of a spring clip. The spring clip can also be referred to as a clip; the spring element is accordingly clipped into the collector body. Furthermore, the spring element can also be injected directly into the collector body and/or into the collector housing. Preferably at least one hole is provided in the base web, in which a pin, a screw, or a rivet can engage.
Alternatively, the spring element could also be 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 collector body or collector segment. Preferably, the collector body and/or the collector segment has a housing section with a curvature which corresponds to the curvature of the grinding disk. 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 rotational axis of the grinding disk within the collector body volume or the collector segment volume.
It has proved to be advantageous if the spring element has at least one wing protruding from the base web. Preferably, the spring element is attached such that the orientation of the protruding wings corresponds approximately to the outer circumference of the collector body.
According to a further embodiment, the spring element could also be arranged radially.
Alternatively, the spring element can have two wings protruding 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 installed, the wings form a tangent to the circular grinding disk and/or to the oval body of the grinding collector.
In a particularly preferred embodiment, the spring element has at least one retaining bracket which is designed to prevent the sealing element from falling out axially from the collector body and/or the collector segment.
According to a further advantageous embodiment, the retaining bracket can be positioned with a first end on an underside of the collector body, with an axial stop for the retaining rail of the sealing element formed on a second end, wherein the retaining bracket can be deflected in the radial direction, based on the axis of rotation of the grinding disk, for the purpose of replacing the sealing element.
Further advantageously, the axial stop may be formed as a stop bar, which preferably extends parallel to the base web. Advantageously, the axial stop formed as a stop bar has a recess, such that a contact surface between the stop bar and the sealing element and/or retaining rail of the brush curtain is reduced. The recess preferably allows for savings in material, as well as for a minimized catch surface for dust. In addition, a friction surface is reduced with respect to the brush curtain, such 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 of spring steel. Particularly preferably, the spring element has a spring stiffness in the axial direction which is less than a stiffness of the brushes of the brush curtain. Alternatively, the spring element can also be designed in several parts.
Particularly preferably, there is a plurality of spring elements arranged along the circumference of the collector body and/or the collector segment. It has been shown to be advantageous if an angle grinder dust collector having a collector body and a collector segment is equipped with five spring elements which are preferably equally spaced from each other.
In a further preferred embodiment, the collector body has a central opening, wherein a drive spindle to which the circular grinding disk will be attached for the grinding operation can project through the central opening. A groove is preferably constructed on the central opening such that the collector body can be attached to an angle grinder with a positive fit, and therefore fixed to the frame thereof
The object is also achieved by an angle grinder having an angle grinder dust collector of the type described above, wherein the collector body is arranged or can be arranged fixed to the frame of the angle grinder.
Further advantages will be 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. A person skilled in the art will expediently consider the features individually and combine them into reasonable further combinations.

In the figures, the same and similar components are numbered with the same reference numerals, wherein:

FIG. 1 shows a plan view of a dust collector for angle grinders, according to the invention;

FIG. 2 shows a first schematic bottom view of the dust collector for angle grinders, according to the invention, having a spring element according to a first alternative;

FIG. 3 shows a second schematic bottom view of the dust collector for angle grinders, according to the invention, having the spring element according to the first alternative;

FIG. 4 shows a third schematic bottom view of the dust collector for angle grinders, according to the invention, having the spring element according to the first alternative;

FIG. 5 shows a sectional view taken along section line A-A in FIG. 1;

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

FIG. 7 shows a perspective view of a spring element according to a second alternative.

EMBODIMENTS

A dust collector 100 for angle grinders is shown in FIG. 1 in a plan view.
The dust collector for angle grinders 100 has a collector body 10 for covering a circular grinding disk, which is not shown in the figures. An axis of rotation R of the grinding wheel is indicated by a dot-dash line. The dust collector 100 for angle grinders 100 also has a collector segment 20 which can be displaced along the collector body 10 along a circumferential direction N of the collector body 10.
The collector body 10 is designed to cover a major portion of the grinding disk, wherein the displaceable collector segment 20 is provided for covering and uncovering a remaining portion of the grinding disk.
As shown in FIGS. 2, 3, 4, and 5, both the collector body 10 and the displaceable collector segment 20 have a sealing element 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′.
Because the dust collector 100 for angle grinders in FIG. 1 has both a collector body 10 and a collector segment 20, the brush curtain 30 is formed in two parts, and/or two brush curtains are included. The sealing element 30 for the collector body 10, designed as a brush curtain, is clamped and/or positioned in the first support rail 31. Furthermore, the sealing element 30 for the collector segment 20, designed as a brush curtain, is clamped or positioned in the second support rail 31′.
The brush curtains 30 serve to seal the collector body 10 and the collector segment 20 to a surface of a material being machined, which is not shown here. Abraded surface particles can be sucked away in the course of the operation (for example, grinding work) via a suction terminal 40 provided on the collector body 10.
The brush curtain 30 is spring-loaded with respect to the collector body 10 and the collector segment 20 in the axial direction, relative to the axis of rotation R of the grinding disk, by a spring element 50. The spring element 50 is shown separately in a first embodiment in FIG. 6, and in a second embodiment in FIG. 7.
The spring element 50 comprises, in the first and second embodiments, a flat base web 51 via which the spring element 50 is attached to the collector body or collector segment 20.
In the first embodiment shown in FIG. 1, the spring element 50 is attached via a pin (see FIG. 2) (for example, hot-spliced), wherein the pin engages in a hole 52.
The second embodiment of the spring element 50 shown in FIG. 7 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 wings 53 projecting from the base web 51 in opposite directions. The wings 53 each exert a spring action on a retaining rail 31 of the brush curtain 30. The wings 53 are oriented, when the spring element 50 is installed, in the direction of the outer circumferential direction N of the collector body 10.
The first retaining rail 31 for the sealing element 30 runs along a closed circumference U around the collector body 10. The circumference U extends along a circular arc A of the collector body 10 and a chord D of the collector segment 20. In this way, the first support rail 31 substantially forms a closed circle with a straight side—namely the chord D of the collector segment 20. As shown in FIGS. 2 and 4, the sealing element 30 for the collector body 10 is arranged only in the support rail 31 along the circular arc A of the collector body 10. The section of the retaining rail 31 along the chord D of the collector segment 20 has no sealing element 30.
The retaining rail 31′ for receiving the sealing element 30 for the collector segment 20 extends along the circular arc B of the collector segment 20 and the chord D of the collector segment 20. The sealing element 30 is located only in the section of the support rail 31′ along the circular arc B of the collector segment 20.
When the dust collector 100 for angle grinders as illustrated in FIG. 4 is closed (that is, the collector segment 20 is closed), the sealing element 30 for the collector segment 20 closes the section of the retaining rail 31 along the chord D of the collector segment 20 which does not have a sealing element 30.
The collector body 10 and the collector segment 20 have retaining clips 55 which are designed to prevent the brush curtain 30 from falling out of the collector body 10 or the collector segment 20 axially. In the embodiment shown in FIG. 1, the retaining bracket 55 protrudes in the axial direction from the underside of the collector body 10, and has a stop for the support rail 31, 31′ of the brush curtain 30 on its free end. The axial stop is designed in the present case as a stop bar 57 which extends substantially parallel to the collector body 10.
The retaining bracket 55 can be deflected in the radial direction with respect to the axis of rotation R, as indicated by the double arrow M, for the purpose of replacing the brush curtain. Thus, the sealing element 30 advantageously designed as a brush curtain can be replaced without the need for a special tool.
The spring element 50 realizes a functional integration—specifically, on the one hand, the spring action in the axial direction, and on the other hand, preventing the brush curtain 30 from falling out of the collector body 10 and/or the collector segment 20 axially.
As can be seen in FIG. 1, the collector body 10 has a central opening 11, wherein a drive spindle, not shown here, to which the circular grinding disk will be attached, can project through the central opening 11. A groove 12 is constructed on the central opening 11, such that the collector body 10 can be attached to an angle grinder (not shown) with a positive fit, and therefore fixed to the frame thereof
The spring elements 50 arranged within a volume of the collector body 10 on the outer edge of the collector body 10 exert a spring action via their respective wings 53 on the support rail 31 of the brush curtain 30.

Claims

1. A dust collector for angle grinders, comprising a collector body for covering a circular grinding disk; a sealing element having sections; a first retaining rail and a second retaining rail, wherein at least some sections of the sealing element are placeable in the first retaining rail and the second retaining rail, and the first rail and the second rail are for sealing the at least some sections of the collector body from a surface to be machined by the grinding disk; having a suction terminal via which abraded surface particles can be sucked out of the collector body; and at least one open spring element

wherein the first retaining rail runs along a closed circumference (U) of the collector body, and the sealing element is spring-loaded in the collector body in an axial direction relative to an axis of rotation (R) of the grinding disk, by the at least one spring element.

2. The dust collector for angle grinders according to claim 1,

wherein the dust collector comprises a collector segment which can be displaced along the collector body in a circumferential direction (N) of the collector body, provided for gradually covering and uncovering a remaining portion of the grinding disk as required, wherein the closed circumference (U) of the collector body extends along a circular arc (A) of the collector body and a chord (D) of the collector segment.

3. The dust collector for angle grinders according to claim 2,

wherein a sealing element is spring-loaded in the axial direction, based on the axis of rotation (R) of the grinding disk, in the collector segment by the at least one spring element.

4. The dust collector for angle grinders according to claim 1,

wherein the spring element has a base web via which the at least one spring element is attached to the collector body.

5. The dust collector for angle grinders according to claim 4,

wherein the at least one spring element has at least one wing protruding from the base web.

6. The dust collector for angle grinders according to claim 3,

wherein the collector body has at least one retaining clip which is designed to prevent the sealing element from falling out axially from the collector body and/or the collector segment.

7. The dust collector for angle grinders according to claim 6,

wherein the retaining bracket is positioned with a first end (55 a) on an underside of the collector body, with an axial stop for the first retaining rail of the sealing element (30) formed on a second end (55 b), wherein the retaining bracket can be deflected in the radial direction, relative to the axis of rotation (R) of the grinding disk, for replacing the sealing element.

8. The dust collector for angle grinders according to claim 7,

wherein the axial stop is formed as a stop bar which runs parallel to the base web.

9. The dust collector for angle grinders according to claim 1,

wherein the at least one spring element is formed as a single piece.

10. The dust collector for angle grinders according to claim 1,

wherein the at least one spring element has a spring stiffness in the axial direction which is less than a stiffness of the sealing element.

11. The dust collector for angle grinders according to claim 1,

wherein a plurality of spring elements is provided along the closed circumference (U) of the collector body.

12. The dust collector for angle grinders according to claim 1,

wherein the collector body has a central opening, wherein a drive spindle to which the circular grinding disk will be attached can project through the central opening wherein a groove is formed on the central opening such that the collector body can be attached to an angle grinder with a positive fit, and therefore fixed to the frame thereof.

13. An angle grinder, having a dust collector, the dust collector comprising a collector body for covering a circular grinding disk; a sealing element having sections; a first retaining rail and a second retaining rail, wherein at least some sections of the sealing element are placeable in the first retaining rail and the second retaining rail, and the first rail and the second rail are for sealing the at least some sections of the collector body from a surface to be machined by the grinding disk; having a suction terminal via which abraded surface particles can be sucked out of the collector body; and at least one open spring element wherein the first retaining rail runs along a closed circumference (U) of the collector body, and the sealing element is spring-loaded in the collector body in an axial=direction relative to an axis of rotation (R) of the grinding disk, by the at least one spring element, wherein the angle grinder has a frame and the collector body is fixed to the frame or can be arranged thereon.

14. The dust collector of claim 4, wherein the base web is flat.

15. The dust collector for angle grinders according to claim 2, wherein the spring element has a base web via which the at least one spring element is attached to the collector body and/or the collector segment.

16. The dust collector of claim 15, wherein the at least one spring element is attached to the collector body and/or the collector segment by a pin, a screw, or a rivet.

17. The dust collector of claim 5, wherein the at least one wing protrudes from the base web in an orientation corresponding to the outer circumference (U) of the collector body.

18. The dust collector of claim 8, wherein the axial stop has a recess such that a contact surface between the stop bar and the first retaining rail is reduced.

19. The dust collector of claim 9, wherein the at least one spring element is spring steel.

20. The dust collector for angle grinders according to claim 2, wherein a plurality of spring elements is provided along the closed circumference (U) of the collector body and/or the collector segment.