Patent Application
20210291320
The invention relates to a sanding block for manual use, in particular for manually sanding surfaces.
Sanding is known as a surface treatment for products or objects in various industrial sectors, such as carpentry and the automotive industry. Sanding can be used for various purposes, such as polishing, smoothing, shaping surfaces, repairs, or for special applications such as removing a layer of paint or surface-grinding a filler from a car body.
Sanding tools are characterized fundamentally by the presence of an abrasive surface that is designed to act abrasively and provided with abrasive materials, and that is brought into contact with the surface to be worked and from which material is then removed. This may be done manually or mechanically. Furthermore, a tool for manual sanding usually has a surface for gripping the tool.
There are already known, for example from EP 11182793 A1, sanding blocks that are intended for manual use, in particular for manual sanding of surfaces, and which have at least one base plate for holding an abrasive article, and at least one sanding block body that has a grip region. It is also known that sanding blocks can be designed in such a manner that they are compatible with standard 150 mm sanding discs, which are actually designed for random-orbit sanders, and can therefore be used for manual sanding.
The invention is based on a sanding block for manual use, in particular for manually sanding surfaces, having at least one base plate for holding an abrasive article, and at least one sanding block body having a grip region. According to the invention, integrated into the sanding block is an accumulator-battery-operated means for suctioning-off sanding dust, which comprises at least one dust box, a motor housing, in which there is provided a drive motor having an impeller wheel, and an accumulator battery for mains-independent supply of electric power to the drive motor.
A sanding block is used for manual application, in particular for manual sanding of surfaces. The sanding block differs from orbital and random-orbit sanders, where automated or motorized sanding is realized by use of a motor, by which a base plate, which is mounted so as to be movable in relation to the orbital and orbital sander, is motor-driven. In the context of this document, therefore, a sanding block is explicitly to be understood as not having a motor for motorized execution of the sanding process. In this sense, the sanding block is used for manual application and manual sanding. The sanding block has a sanding block body that, in an embodiment of the sanding block, may be realized as a housing of the sanding block. The sanding block body also has a grip region. The grip region enables a user to grip the sanding block firmly in order to be able to guide it in a controlled manner during the execution of a manual sanding motion, in particular over a workpiece. In an embodiment of the sanding block, the grip region may be designed as a handle. Alternatively or additionally, the grip region may be at least partially rubberized to increase its grip.
A base plate of the sanding block serves to hold and fasten an abrasive article to the sanding block, in particular during execution of the sanding process. The base plate is preferably realized as a part of the sanding block body, being integral with it. The base plate is designed to receive an abrasive article, or may itself have at least one abrasive surface, comparable to a metal plane. In an embodiment of the sanding block, the base plate constitutes a substantially flat surface. In an embodiment of the sanding block, the base plate has a layer of material suitable for realizing a hook-and-loop connection, for example a layer of loops or a layer of flexible barbs.
An accumulator-battery-operated means for suctioning-off sanding dust is provided, integrated in the sanding block, i.e. arranged in or on the sanding block body and/or at least partly integrated into the sanding block body. The accumulator-battery-operated means for suctioning serves to suction-off sanding dust produced during a sanding process by manual application of the sanding block. For this purpose, the accumulator-battery-operated means for suctioning comprises at least one dust box, a motor housing, in which a drive motor having an impeller wheel is provided, and an accumulator battery for mains-independent supply of electric power to the drive motor. In this way, by use of the accumulator-battery-operated suctioning means, sanding dust produced during a sanding process can be suctioned-off the surface to be worked and collected in the dust box in a particularly efficient manner.
The drive motor, at least when having been switched on, is supplied with energy by an accumulator battery for mains-independent supply of electric power. In the context of this application, an accumulator battery is to be understood to mean an accumulator battery pack, consisting of at least one electrochemical accumulator-battery cell, which supplies an electrical energy. The accumulator battery constitutes, in particular, a rechargeable secondary battery that, when connected to a charging station, can be recharged. Suitable for energy supply, for example, are accumulator batteries having a cell chemistry that provides a high power density and/or energy density such as, for example, accumulator batteries having lithium and lithium-ion cell chemistry, in particular lithium-iron-phosphate, lithium-manganese oxide, lithium-nickel-cobalt manganese oxide, superlithiated lithium-nickel-cobalt manganese oxide, lithium-sulfur, lithium-polymer and lithium-oxygen accumulator batteries.
In this way it is possible to specify an autonomous sanding block that is independent of the mains power supply, i.e. in particular cordless, but that still has means for suctioning-off sanding dust. The sanding block thus constitutes a particularly handy tool that is always ready for use, and that can be used or applied in a clean environment since, owing to the accumulator-battery-operated suctioning means, the risk of flying dust and, in particular, the risk of contamination of the environment are minimized. Furthermore, owing to the integrated accumulator-battery-operated suctioning means, there is no need for an external suctioning means in addition to the sanding block. In particular, it is thereby possible to dispense with an external vacuum cleaner and/or a hose connection from an external vacuum cleaner to the sanding block, which greatly impedes the use of the sanding block during a manual sanding motion.
Furthermore, owing to the integration of the accumulator-battery-operated suctioning means, the weight of the sanding block can advantageously be increased and balanced in such a manner that the sanding block lies very well in the hand of the user during a sanding process, i.e. during a manual sanding motion.
In an embodiment of the sanding block, the dust box can be detachably fixed to the motor housing and can be removed from the sanding block from the outside. In this way, it is possible to empty the dust box easily as soon as it is filled with sanding dust. For this purpose, the dust box can be removed from the sanding block, emptied and then put back into the sanding block, such that it is again detachably fixed to the motor housing.
In an alternative embodiment, the dust box may also be realized in the form of a flexible dust bag or the like, which can be detachably fixed to the motor housing. This dust bag may be such that it can be stowed inside the sanding block body, or can be fixed to the outside of the sanding block body.
Accordingly, in an alternative or additional embodiment of the sanding block, the accumulator battery may also be such that it can be detachably fixed to the sanding block body and can be removed from the sanding block from the outside. In this way, when the accumulator battery is discharged it can easily be replaced by another, charged, accumulator battery. In an embodiment of the sanding block, the accumulator battery and/or the dust box can be received, at least portionally, in the grip region of the sanding block, in particular in a handle of the sanding block. In this way, it is possible to specify an arrangement of the removable components of the sanding block that is particularly accessible to the user, such that the accumulator battery can be easily replaced or the dust box can be easily emptied.
In an embodiment of the sanding block, there is a control element, for switching the drive motor on and off, arranged on an outer surface of the sanding block. The control element serves to start and stop the suctioning. Such a control element may be realized, for example, in the form of a pressure switch, a pushbutton, a slide switch, or the like. In particular, the control element is arranged on the side of the sanding block that faces the user when the sanding block is being used. Preferably the control element is arranged in or on the grip region, in particular in or on the handle, such that it is always accessible to the user while performing the manual sanding motion.
In an embodiment of the sanding block, realized on the motor housing there is an air passage opening, to which the dust box can be detachably fastened, wherein the dust box has at least one further air passage opening, on which a filter medium can be arranged. It is thereby possible to specify an accumulator-battery-operated suctioning means that is of a particularly simple structural design but that still operates in a particularly efficient manner. The impeller wheel, which is set in motion by the drive motor, generates an airflow that is directed into the motor housing from the surface of the workpiece to be worked. The airflow continues through the motor housing and through the air passage opening into the dust box, and dust transported by the airflow is caught in the filter medium when leaving the dust box through the other air opening.
In an embodiment of the sanding block, the base plate has at least one opening for suctioning-off sanding dust, through which dust can be suctioned-off. In particular, the sanding block—in an embodiment the base plate—has an air guide element for suctioning-off sanding dust, which in particular is connected to the at least one opening and to the accumulator-battery-operated means for suctioning-off sanding dust. In this way, the sanding dust produced during the sanding process can be suctioned-off, directly at the point of origin, from the surface of the work piece to be worked. Contamination of the environment by suctioning-off of dust not effected directly on the workpiece is avoided.
In an alternative or additional embodiment of the sanding block, the sanding block has a dust suction nozzle, for suctioning-off sanding dust, which is arranged on the outside of the sanding block. The dust suction nozzle in this case is likewise connected, by use of an air guide element, to the accumulator-battery-operated means for suctioning-off sanding dust. In this way, because of the design, reliable suctioning-off of dust on the workpiece can be specified. The dust suction nozzle in this case may be arranged, for example, around the sanding block. Alternatively, the dust suction nozzle may also be arranged on particular sides of the sanding block, for example on the sides of the sanding block in the direction of which the manual sanding motion is preferably effected during a sanding process.
The invention also relates to a system comprising at least one sanding block according to the description above, and at least one abrasive article that is designed to be connectable to the base plate of the sanding block, wherein the base plate and the abrasive article respectively have at least one opening, preferably respectively a plurality of openings, for suctioning-off sanding dust.
The “abrasive article” may be, for example, a coated abrasive article, in particular sandpaper, abrasive foam, abrasive fabric, knitted abrasive fabric, non-woven abrasive fabric, or the like. Furthermore, in principle, bonded abrasive articles are also conceivable, such as typically resin-bonded abrasive cut-off and roughing disks. The abrasive article may exist, in particular, in differing product forms, for example as a sanding disk or sanding strip. In an embodiment of the system, one opening of the base plate and one opening of the abrasive article, in particular the plurality of openings of the base plate and the plurality of openings of the abrasive article, are substantially congruent in a state in which the abrasive article has been connected the base plate of the sanding block.
The invention is explained in greater detail in the following description on the basis of exemplary embodiments represented in the drawings. The drawings, the description and the claims contain numerous features in combination. Persons skilled in the art will expediently also consider them individually and combine them to form appropriate further combinations. In the figures, elements that are the same are denoted by the same references.
There are shown:
The layer of material 16 suitable for realizing the hook-and-loop connection is in this case located at least on the underside, in particular at least also on the side faces, of the base plate 12. The base plate in this case is shaped, in particular, in such a manner that it realizes at least one right-angled corner, and quite particularly realizes two or four right-angled corners. By use of these right-angled corners, a workpiece can also be sanded or polished well into corners. In order to make the sanding block 10 also compatible with round abrasive articles, such as those commonly commercially available, it is provided that the layer of material 16 is also arranged on the side faces of the base plate 12. In this way, the circular segments of the round abrasive articles 14 that project from the underside (sanding side) of the base plate 12 can be folded up and fastened to the layer of material, while at the same time the right-angled corners of the underside of the base plate 12 are covered with abrasive article 14. The dimensions of the base plate 12 in this case are selected, by way of example, in such a manner that a 150 mm abrasive article 14 can be fastened to the base plate 12 without wrinkles, and the projecting circle segments can also be folded over onto the side faces of the base plate 12 without wrinkles.
The sanding block 10 has a sanding block body 18 having a grip region 20, the grip region 20 in this case being shaped in the form of a knob (convex) and thus conforming particularly smoothly to the hand surrounding the grip region. The surface of the grip region 20 may be rubberized (not represented in greater detail here).
The sanding block body 18 at least substantially encloses, as a type of housing, the components of the sanding block that are necessary and/or expedient for the realization of an accumulator battery-operated means 22, integrated into the sanding block 10, for suctioning-off sanding dust, see
Provided inside the sanding block 10, in particular inside the sanding block body 18, there is also a dust box 28 and a motor housing 30. The dust box 28 can be detachably fixed to the motor housing 30. Arranged in the motor housing 30 are at least one impeller wheel 32 and a drive motor 34, the impeller wheel 32 being connected to the drive motor 34 in a rotationally movable manner, in particular so as to be movable about a central axis of rotation (rotation shaft). The impeller wheel 32 has a plurality of ribs (“blades”, not represented in greater detail here), which are inclined in the direction of the axis of rotation and which, upon rotation of the impeller wheel 32, accelerate air from a region close to the axis of rotation to a radially distant region (see arrows in
Arranged on a side of the grip region 20 that faces toward the user, i.e. on an outer face of the sanding block 10, there is a control element 36 for switching the drive motor 34 on and off. In this exemplary embodiment, the control element 36 is realized as a capacitive switch, which detects the presence of a hand on the grip region and, after a defined dwell time of the hand, enables the supply of power to the drive motor 34. For this purpose, the accumulator battery 34 is connected in an electrically conductive manner, via contact elements, to an electronics unit (not represented in greater detail here) that is arranged inside the motor housing 30 and connected to the control element 36 for switching the drive motor 34 on and off. The electronics unit in this case is designed at least for switching the drive motor 34 on and off upon a corresponding actuation of the operating element 36, and for controlling the drive motor 34.
As an illustration, the motor housing 30 and the dust box 28 realize a vacuum-cleaner housing, which has air passage openings 38 on both the motor housing 30 and the dust box 28. In the exemplary embodiment represented, the dust box 28 is at this point (interface) detachably connected or connectable to the motor housing 30, in particular fixed to it. Arranged in the region of these air passage openings 38, preferably between the dust box 28 and the motor housing 30, is a viscoelastic seal, in particular a ring-shaped rubber sleeve (not represented in greater detail here), at least to seal the motor housing 30 and the dust box 28. This seal is preferably designed to fix a disposable filter medium 40 and/or a filter holder carrying the disposable filter medium 40 to the motor housing 30 in an airtight manner, in particular to lock it in place. This disposable filter medium 40 serves to allow an airflow from the motor housing 30 into the dust box 28 (“permeable to airflow”), but to prevent an airflow in the opposite direction, i.e. backflow. In this way, it is ensured that dust 42 already in the dust box 28 cannot return to the motor housing 30.
The dust box 28 is designed in such a manner that one side of the dust box 28 is realized as part of the surface 44 of the sanding block body 18. In this way, the dust box 28 can be received, at least portionally, in the grip region 20 of the sanding block 10. Furthermore, in this way the dust box 28 is detachably fixed to the motor housing 30 and can be removed from the sanding block 10 from the outside. For this purpose, arranged in the region between the control element 36 and the dust box 28, preferably also on a side of the sanding block 10 that faces toward the user, there is preferably a spring-loaded actuating element 46 that can be actuated to release the dust box 28 fixed to the motor housing 30. If the dust box 28 is filled with dust 42, it can be removed from the sanding block body 18, emptied and then reinserted in a particularly simple manner. In the side of the dust box 28 that is realized as the surface 44 of the sanding block body 18 there are openings, which also serve as air passage openings 38 and which are preferably at least partially covered by a, in particular fine, filter medium 48. For this purpose, a filter holder (not represented in greater detail here) that carries the filter medium 48 may be fixed in an airtight manner, in particular latched in place, inside the dust box 28. In this way, an air passage opening 38, to which the dust box 28 is detachably fixed, is realized on the motor housing 30, the dust box 28 having at least one further air passage opening 38, at which a, in particular fine, filter medium 48 can be or is arranged.
A deflection means 50 is arranged in the motor housing 30, facing the airflow opening 38, the deflection means 50 preferably being aligned obliquely in relation to the axis of rotation of the impeller wheel 32. Realized on the motor housing 30, in the region of the axis of rotation of the impeller wheel 32, there is an air guide element 52, which is designed to guide an airflow (arrows in
In the section of the exemplary embodiment represented in
In an alternative embodiment of sanding block 10, as represented in
During the operation of the drive motor 34, a generated negative pressure causes an airflow (arrows) to be generated, through the openings 54 or through the dust suction nozzle 58 along the air guide element 52 into the motor housing 30, which carries along dust 42, occurring on the workpiece surface, into the dust box 28. The airflow enters the dust box 28 via the deflection means 50. There, the airflow exits the sanding block 10, via the filter medium 48, as a cleaned airflow, and the dust 42 remains in the dust box 28.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2018 210 567.7 | Jun 2018 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/066041 | 6/18/2019 | WO | 00 |
