Patent Application
20190015948
The present invention relates to a dust collector for an angle grinder, comprising a collector body for covering a circular grinding wheel, and a sealing element extending along an outer periphery of the collector body for at least partially sealing the collector body against a surface to be machined by means of the grinding wheel. The dust collector for an angle grinder has a suction connection, by way of which material removed from the surface can be suctioned out of the collector body. The sealing element can be, for example, a brush curtain, lamellae, or the like. In addition, it is also possible that the sealing element involves a single solitary elastic element or also multiple individual elastic elements. The elastic element can be a foam, an elastomer (for example, rubber, natural rubber, etc.), or the like.
Dust collectors for angle grinders of the type mentioned at the outset are known in principle from the prior art. They are used to avoid propagation of dust during grinding work, in order to protect the health of a user of the angle grinder. Equipping the collector body with a sealing element, for example, a peripheral brush curtain or with multiple brushes, such that the collector body terminates at the surface of the workpiece to be machined, is known. If the angle grinder is pressed at a slight angle against the surface of the workpiece to be machined, the sealing element can thus seal a gap possibly arising between collector body and surface of the workpiece to be machined in a compensating manner.
It is the object of the present invention to provide a dust collector for an angle grinder which offers improved usage options.
The object is achieved in that, in an axial direction with respect to the axis of rotation of the grinding wheel, the sealing element is spring-mounted in the collector body by means of at least one spring element.
The invention includes the finding that in particular during overhead operation of an angle grinder, a collector body comprising brush curtain rigidly fastened thereon according to the prior art is drawn downward by gravity and a suction hose possibly connected to the suction connection. A gap can thus disadvantageously arise between brush curtain and surface to be machined. The brush curtain is always pressed toward the surface to be machined by the spring-mounted brush curtain in the collector body according to the invention, whereby a gap is avoided or at least substantially reduced.
In this respect, the invention also includes the finding that a worn brush curtain can typically have a high stiffness in relation to the axial direction, and therefore disadvantageously a large amount of force has to be applied to move the grinding wheel toward the surface of the workpiece to be machined against the stiffness of the warned brush curtain. This is the case because the brush curtain is rigidly fastened to the collector body in dust collectors for angle grinders of the prior art, as already mentioned at the outset.
In addition, the present invention includes the finding that a grinding wheel which is already strongly worn, in particular a diamond cup wheel, is used in conjunction with a new dust collector for an angle grinder and the user disadvantageously has to press the grinding wheel, which has already become flat, toward the surface of the workpiece to be machined against the relatively high stiffness of the still stiff brush curtain of the new dust collector for an angle grinder. A worn grinding wheel frequently has a lesser height in this case, i.e., a less concave shape than a new or unworn grinding wheel.
In the dust collector for a grinding wheel according to the invention, the spring element assumes the axial movement of the sealing element with respect to the collector body. Possible radial displacements can still be compensated for by the sealing element itself. In the scope of the invention, a spring element is to be understood as a preferably discrete spring element and not merely a possible spring action or yielding nature of the brush curtain in the axial direction.
In addition, the invention includes the finding that dust collectors for angle grinders of the prior art cannot be refined to achieve the spring action according to the invention such that a spring element is provided between collector body and angle grinder housing, for example. This has the disadvantage during overhead work that the intrinsic weight of a suction hose connected to the suction connection would compress such a spring in an undesired manner.
In a particularly preferred embodiment, the collector body is designed to cover a predominant part of the grinding wheel. The dust collector for an angle grinder can have a collector segment displaceable along the collector body in the peripheral direction of the collector body, which is provided to cover and expose a remaining part of the grinding wheel gradually as needed. This enables grinding operation close to the wall by means of the remaining part of the grinding wheel, which is not covered by the collector body. In an axial direction with respect to the axis of rotation of the grinding wheel, a sealing element is preferably also spring-mounted by at least one spring element in the collector segment.
It has proven to be advantageous if the spring element has a preferably flatly formed base web. The spring element can be fastened on the collector body and/or on the collector segment via the base web. Fastening preferably 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 fastened directly in the collector body by means of a spring clip via an undercut. The spring clip can also be referred to as a clip, and therefore the spring element is clipped into the collector body. Furthermore, the spring element can also be injection molded directly into the collector body or into the collector housing, respectively. At least one hole is preferably provided in the base web, in which a pin, a screw, or a rivet can engage.
Alternatively, it could also be provided that the spring element is fastened on the first and/or second holding rail for the sealing element.
The spring element is or the spring elements are preferably arranged inside a volume defined by the collector body or collector segment. The collector body and/or the collector segment preferably has a housing section, the curvature of which corresponds to the curvature of the grinding wheel. The spring element is preferably arranged in the immediate vicinity of this section. The spring element is preferably arranged as far as possible from an axis of rotation of the grinding wheel inside the collector body volume or the collector segment volume.
It has proven to be advantageous if the spring element has at least one spring rocker arm protruding from the base web. The spring element is preferably attached such that the orientation of the protruding spring rocker arm preferably approximately corresponds to the outer circumference of the collector body.
According to a further embodiment, it could also be provided that the spring element is also radially arranged.
Alternatively, it can also be provided that the spring element has two spring rocker arms protruding from the base web. In this way, a higher level of stability of the spring element in an installed state and also an enhanced spring force can be achieved.
When the spring element is installed, the spring rocker arms form a tangent to the circular grinding wheel or to the oval body of the dust collector.
In one particularly preferred embodiment, the spring element has at least one holding bracket, which is designed to prevent the brush curtain from falling axially out of the collector body and/or the collector segment.
The holding bracket can protrude in the axial direction from the base web. An axial stop for a holding rail of the brush curtain is preferably formed at its other end, i.e., the end facing away from the base web.
The holding bracket can preferably be deflected in the radial direction, in relation to the axis of rotation of the grinding wheel, for the purpose of replacing the brush curtain. Furthermore, the axial stop can advantageously be formed as a stop web, which preferably extends parallel to the base web. The axial stop formed as a stop web advantageously has a recess, and therefore a contact surface between stop web and brush curtain or holding rail of the brush curtain is reduced. The recess preferably causes a material savings and a smaller engagement surface for dust. Moreover, a friction surface with respect to the brush curtain is reduced, and therefore it can be moved particularly easily in the axial direction.
Alternatively to the holding bracket being able to protrude in the axial direction from the base web, the holding bracket can be designed as a clamping sleeve, which is arranged on a side of a respective spring rocker arm facing away from the base web. The clamping sleeve is preferably designed for clamping a holding rail of the brush curtain. In other words, the clamping sleeve which holds the brush curtain is itself spring-mounted.
It has proven to be advantageous if the spring element is formed in one piece, preferably from spring steel. The spring element particularly preferably has a spring stiffness in the axial direction which is less than a stiffness of the brushes comprised by the brush curtain. Alternatively, the spring element can also be embodied in multiple pieces.
A plurality of spring elements is particularly preferably provided along the circumference of the collector body and/or the collector segment. It has proven to be advantageous if a dust collector for an angle grinder, which has a collector body and a collector segment, is equipped with five spring elements, preferably spaced apart uniformly from one another.
In a further preferred embodiment, the collector body has a central opening, through which a drive spindle, on which the circular grinding wheel is to be attached for grinding operation, can protrude through the central opening. A groove is preferably formed at the central opening, and therefore the collector body can be fastened interlocked and thus fixed on the frame on an angle grinder.
The object is also achieved by an angle grinder comprising a dust collector for an angle grinder of the above-described type, wherein the collector body is arranged or can be arranged fixed on the frame on the angle grinder.
Further advantages result from the following description of the figures. Various exemplary embodiments of the present invention are illustrated in the figures. The figures, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and combine them to form reasonable further combinations.
In the figures, identical and equivalent components are identified by identical reference signs. In the figures:
A dust collector 100 for an angle grinder according to the invention is shown in a bottom view in
The collector body 10 is designed to cover a predominant part of the grinding wheel, wherein the displaceable collector segment 20 is provided for covering and exposing a remaining part of the grinding wheel.
Both the collector body 10 and also the displaceable collector segment 20 have a sealing element 30 in the form of a brush curtain. Since the dust collector 100 for the angle grinder of
According to the invention, in an axial direction with respect to the axis of rotation R of the grinding wheel, the brush curtain 30 is spring-mounted in the collector body 10 and the collector segment by means of at least one spring element 50. The spring element 50 is shown isolated on the left side of
The spring element 50 has a flatly formed base web 51, via which the spring element 50 is fastened on the collector body or collector segment 20. In the exemplary embodiment shown in
The spring element 50 has two spring rocker arms 53 protruding from the base web 51 in opposing orientations. The spring rocker arms 53 exert a spring action on a holding rail 31 of the brush curtain 30. The spring rocker arms 53 are oriented in the direction of the outer periphery U of the collector body 10 when the spring element 50 is installed.
The spring element 50 has a holding bracket 55, which is designed to prevent the brush curtain 30 from falling axially out of the collector body 10 or the collector segment 20, respectively. In the exemplary embodiment shown in
The holding bracket 55 can be deflected in the radial direction, indicated by the double arrow, for the purpose of replacing the brush curtain. The brush curtain 30 can thus advantageously be replaced without a tool being required.
As is apparent from
As can be inferred from
It can be seen well that the spring elements 50 arranged inside a volume of the collector body 10 at the outer edge of the collector body 10 exert a spring action on the holding rail 31 of the brush curtain 30 by way of the respective spring rocker arms 53 thereof. At the same time, the respective stop webs 57 form an axial stop for the holding rail 31, and therefore it is held securely inside the collector body 10.
The spring element 50 shown in
Finally,
Two holes 52, 52′ are provided on the base web 51 of the spring element 50 of
| Number | Date | Country | Kind |
|---|---|---|---|
| 16156030.5 | Feb 2016 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/053244 | 2/14/2017 | WO | 00 |
