U.S. patent application number 16/075718 was filed with the patent office on 2019-02-07 for dust collector for angle grinder.
The applicant listed for this patent is Hilti Aktiengesellschaft. Invention is credited to Konstantin BAXIVANELIS, Sarah HARDER.
Application Number | 20190039207 16/075718 |
Document ID | / |
Family ID | 55361408 |
Filed Date | 2019-02-07 |
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United States Patent
Application |
20190039207 |
Kind Code |
A1 |
HARDER; Sarah ; et
al. |
February 7, 2019 |
DUST COLLECTOR FOR ANGLE GRINDER
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.
Inventors: |
HARDER; Sarah; (Augsburg,
DE) ; BAXIVANELIS; Konstantin; (Kaufering,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hilti Aktiengesellschaft |
Schaan |
|
LI |
|
|
Family ID: |
55361408 |
Appl. No.: |
16/075718 |
Filed: |
February 14, 2017 |
PCT Filed: |
February 14, 2017 |
PCT NO: |
PCT/EP2017/053240 |
371 Date: |
August 6, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24B 55/102 20130101;
B24B 23/028 20130101 |
International
Class: |
B24B 55/10 20060101
B24B055/10; B24B 23/02 20060101 B24B023/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2016 |
EP |
16156035.4 |
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 (55a)
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 (55b), 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.
Description
[0001] 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.
[0002] 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.
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] Alternatively, the spring element could also be attached to
the first and/or second retaining rail for the sealing element.
[0020] 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.
[0021] 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.
[0022] According to a further embodiment, the spring element could
also be arranged radially.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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
[0031] 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.
[0032] 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.
[0033] In the figures, the same and similar components are numbered
with the same reference numerals, wherein:
[0034] FIG. 1 shows a plan view of a dust collector for angle
grinders, according to the invention;
[0035] 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;
[0036] 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;
[0037] 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;
[0038] FIG. 5 shows a sectional view taken along section line A-A
in FIG. 1;
[0039] FIG. 6 shows a perspective view of a spring element
according to a first alternative; and
[0040] FIG. 7 shows a perspective view of a spring element
according to a second alternative.
EMBODIMENTS
[0041] A dust collector 100 for angle grinders is shown in FIG. 1
in a plan view.
[0042] 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.
[0043] 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.
[0044] 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'.
[0045] 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'.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] 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.
[0058] 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
[0059] 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.
* * * * *