Hand sander for sanding wall surfaces at corners between two walls

Abstract

Hand sander for sanding wall surfaces at corners between two walls (comprehensive) • two plates, each having two adjacent edges and a flat front surface for mounting a grinding wheel, • a joint by which the two plates are pivotably connected about an axis running along the two adjacent edges, • a locking device for locking the two plates in a set swivel position and • a handle located on the back of the two plates and connected to them, to move the two plates along the surfaces to be sanded.

Description

[0001] The invention relates to a hand sander for sanding wall surfaces at corners between two walls.

[0002] Hand sanders are sanding tools used to smooth plasterboard or interior plaster in preparation for the application of interior paint, wallpaper, or other interior wall coverings. Hand sanders are used to sand the interior surfaces of walls or ceilings. They feature a flat front plate and a loop handle on the back. Sandpaper (e.g., a sanding disc) is applied to the front plate, unwrapped along the outer edges of the plate, and secured to the back of the plate using Velcro fasteners or clamps.

[0003] Long-neck sanders (also called "Giraffe" - a registered trademark of Flex) are also known. These sanders feature a telescopic arm with a disc-shaped working head at the front end and a handle at the rear. The working head incorporates a drive motor and a sanding disc on one side and is pivoted to adapt to the wall surface to be sanded.

[0004] A problem when sanding plaster and plasterboard surfaces is the corners between a jamb wall (or a kinked wall) and a sloping roof, between a sloping roof and a mezzanine floor and between two sloping roofs in the gable area.

[0005] Using a hand sander or a long-reach sander, you must approach the corners from different sides. Working from different sides can lead to uneven smoothing of the interior wall surfaces in the corner area.

[0006] Hand sanders with a 90° angle plate (also known as "90° inside corner sanders") are already well known. While these hand sanders facilitate even smoothing of wall surfaces, they are only suitable for inside corners with a 90° angle. However, the angles between the sloped roof and the adjacent walls deviate from a right angle and can vary considerably between different houses.

[0007] Based on this, the object of the invention is to provide a grinding device that facilitates the uniform smoothing of wall surfaces at corners between two walls, regardless of the angle between the wall surfaces.

[0008] The object is achieved by a hand grinder according to claim 1. Advantageous embodiments of the hand grinder according to the invention are specified in subclaims and in the description.

[0009] The hand sander according to the invention for sanding wall surfaces at corners between two walls comprises • two plates, each having two adjacent edges and a flat front surface for the attachment of a grinding wheel, • a joint by which the two plates are pivotally connected around an axis running along the two adjacent edges, • a locking device for locking the two plates in a set swivel position and • a handle located on the back of the two plates and connected to them to move the two plates along the surfaces to be sanded.

[0010] The hand sander according to the invention has two plates that are connected to each other via a joint with adjustable angular alignment in order to adapt to the respective angle of a corner between two walls. In addition, the hand sander has a locking device to fix a set pivoting position of the two plates so that they do not change when working on a corner area. An advantage is that the hand sander can be adjusted to any corner angle, allowing it to be used to smooth wall areas at variable corners between a sloping roof and a jamb wall (or a kinked wall), a mezzanine, or another sloping roof (collectively referred to as "adjacent wall"). The hand sander can also be used to smooth wall areas at 90° corners between two walls or between a wall and a ceiling.By precisely aligning the plates of the hand sander according to the invention to the respective angle, even smoothing of wall surfaces in the corner area can be easily achieved by placing the hand sander at the corner and moving it along the corner. Adjusting the hand sander to the respective angle can be done quickly and easily. The hand sander can be designed to be suitable for use on corners with widely varying angles. Adjustability can be achieved, in particular, in a range from over 90° to 90°, and if necessary, to below 90°.

[0011] According to one embodiment of the invention, the joint has at least one pair of curved guides, each with a curved slot, wherein one curved guide of the pair is firmly connected to the back of one plate and the other curved guide of the pair is firmly connected to the back of the other plate, the centers of the radii of curvature of the curved slots of the two curved guides fall into the adjacent edges of the two plates, and an axle is inserted through the two curved slots, which are connected at both ends to projections that can be clamped to the outer sides of the two curved guides via a clamping device in order to clamp them in the set pivot position. In this embodiment, the locking device is integrated into the joint, since the axle of the joint is also used to clamp the two curved guides in the set pivot position by means of the clamping device.

[0012] In an alternative design, the locking device is separate from the joint. For example, the locking device can be a threaded clamp connected to the two plates at the ends.

[0013] The joint can also be designed in a manner other than using two curved guides. For example, the joint can be formed directly at the adjacent edges of the two panels, as in a rod hinge or a band hinge. This may result in the hand grinder being somewhat wider at the adjacent edges of the two panels than with a joint with curved guides, where the adjacent edges do not include a joint.

[0014] According to a further embodiment, the joint has two pairs of curved guides, with the two pairs connected to the two plates at a distance from each other, and the axis extending through the curved slots of the two pairs. This creates a particularly stable joint that can hold the plates precisely in the set pivot position.

[0015] In addition, this design allows the axle to be gripped between the two pairs of curved guides and used as a handle.

[0016] According to another embodiment, the curved guides are each formed by a curved piece with a curved slot and firmly connected at one end to one of the two plates. This results in a particularly simple design.

[0017] According to another design, each plate is integrally connected to each associated curved guide. This is advantageous for production, assembly, and the strength of the hand grinder.

[0018] According to a further embodiment, the clamping device comprises a rod arranged between the two pairs of curved guides, at the ends of which the mutually facing curved guides of the two pairs rest, threaded bolts protruding from the two ends of the rod, each of which is inserted through the elongated holes of the two curved guides of a pair, and screw heads firmly connected to the threaded bolts or nuts screwed onto the threaded bolts, which rest against the mutually facing curved guides of the two pairs. By tightening the screw heads or the nuts, the two curved guides of the pairs can be clamped together, so that the swivel joint is clamped in the set swivel position. If the threaded bolts are firmly connected to screw heads, the rod has internal threads into which the threaded bolts can be screwed.When nuts are screwed onto the threaded bolts, the threaded bolts are firmly connected to the ends of the rod.

[0019] According to one embodiment, each threaded bolt is inserted through a central through-hole of an adjusting disc which has a hexagonal recess on one end face with its center in the middle of the through-hole, wherein the through-hole and the recess are designed such that the threaded bolt can be inserted through the through-hole and the screw head or the nut can be positively inserted into the recess so that the screw head or the nut can be adjusted by turning the adjusting disc. The adjusting disc, which has a larger diameter than the screw head or the nut, makes it easier to manually tighten and loosen the joint. According to a further embodiment, the adjusting disc has a knurling on the outer circumference which makes it easier to turn the adjusting disc by hand.

[0020] According to another design, a handle protrudes radially outward from the bar. The handle can be adjusted between the plates as needed. The radially protruding handle allows for a particularly good grip on the hand sander and allows it to be moved over the surfaces to be sanded with the required contact pressure.

[0021] The handle can also be designed separately from the joint. For example, a bow handle can be firmly connected to only one of the two plates.

[0022] According to another design, the panels have bevels on the backs of the adjacent edges. These bevels create sharp edges or cutting edges, allowing the two panels to be pivoted tightly around the adjacent edges. This enables particularly precise sanding of the corners.

[0023] According to a further embodiment, the plates have further bevels on the opposite edges on the back sides. These additional bevels facilitate wrapping the edge areas of sandpaper around the opposite edges of the plates and securing the sandpaper to the backs of the plates.

[0024] According to another embodiment, the adjacent edges of the two panels are longer than the opposite edges. This allows the hand sander, which is placed against a corner with adjacent edges, to be moved closer to the ends of the corners.

[0025] According to another embodiment, the side edges of the two panels are bevelled or curved, which further facilitates sliding them towards the ends of the corners.

[0026] According to a further embodiment, the two plates each have a hook-and-loop fastener on their backs for forming a hook-and-loop connection with a hook-and-loop fastener of a sandpaper, which can be applied to the front sides of the two plates and folded around the opposite edges of the two plates. Alternatively, instead of hook-and-loop fasteners, the two plates on their backs have clamps for securing the edges of the sandpaper folded around the edges of the plates.

[0027] According to a further embodiment, the hand grinder is made of plastic and / or metal.

[0028] The invention is explained in more detail below with reference to the accompanying drawings of exemplary embodiments. In the drawings: Fig. 1 a hand grinder according to the invention in a perspective view of the front; Fig. 2 the same hand grinder in a perspective view of the back; Fig. 3 the two plates of the same hand grinder in a perspective view of the back; Fig. 4a-c Bar with handle of the same hand grinder in a front view ( Fig. 4a), in a bottom view ( Fig. 4b) and in a side view ( Fig. 4c); Fig. 5a, b Adjusting disc of the same hand grinder in a front view ( Fig. 5a) and in a top view ( Fig. 5b); Fig. 6 the two plates of a second embodiment of the hand grinder according to the invention in a perspective view of the rear.

[0029] According to Fig. 1 and Fig. 2, a hand grinder 1 has two plates 3, 4 aligned at an angle 2 to each other, which have two adjacent edges 5, 6 and each have a flat front side 7, 8.

[0030] The two plates 3, 4 are pivotally connected to each other via a joint 9. The axis 10 of the joint 9, about which the two plates 3, 4 pivot, runs along the two adjacent edges 5, 6 of the two plates 3, 4.

[0031] Furthermore, a locking device 11 is provided, which serves to lock the two plates 3, 4 in the respectively set pivot position.

[0032] Finally, the hand sander 1 has a handle 12, which is arranged on and connected to the backs 13, 14 of the two plates 3, 4. The handle 12 serves to move the two plates 3, 4, which are set in a specific pivoting position, along the surfaces to be sanded at a corner of a room.

[0033] How better in Fig. As can be seen in Figure 3, the joint 9 has two pairs 15, 16 of curved guides 17, 18, 19, 20, wherein the two pairs of curved guides are connected to the two plates 3, 4 at a distance from one another. Each curved guide 17, 18, 19, 20 has a curved slot 21, 22, 23, 24, wherein the centers of the radii of curvature of the curved slots of the two curved guides fall into the adjacent edges 5, 6 of the two plates 3, 4.

[0034] The curved guides 17, 18, 19, 20 are each formed by an arcuate piece 25, 26, 27, 28, which has the curved slot 21, 22, 23, 24 and is firmly connected at one end to one of the two plates 3, 4. The adjacent edges 5, 6 of the two plates 3, 4 are longer than the opposite edges 29, 30 of the two plates 3, 4. The lateral edges 31, 32 of the two plates 3, 4 are curved in an arc shape.

[0035] The curved pieces 26, 27 on the plate 4 are closer to each other than the curved pieces 25, 28 on the plate 3, so that the first-mentioned plate 4 with its curved pieces 26, 27 can be pivoted between the curved pieces 25, 28 of the second-mentioned plate 3.

[0036] The adjacent edges 5, 6 have a bevel 33, 34 on the back 13, 14 of the plates 3, 4, so that these edges 5, 6 are designed like cutting edges.

[0037] At the opposite edges 29, 30, the panels 3, 4 have a further bevel 35, 36 on the back 13, 14, so that these edges 29, 30 are also shaped like cutting edges. Hook-and-loop strips 37, 38 of a hook-and-loop fastener 39 are glued to the backs 13, 14 of the two panels 3, 4 at the opposite edges 29, 30.

[0038] According to Fig. 4, the eyelet-shaped handle 12 is connected radially to a cylindrical rod 41 via a lateral web 40. The rod 41 has boreholes 42, 43 at both ends, in which internal threads 44, 45 are arranged.

[0039] According to Fig. 1 and Fig. 2, the two plates 3, 4 are pivoted together slightly around the axis 10, which runs along their adjacent edges 5, 6, so that the curved pieces 27, 28 of one plate 4 engage between the curved pieces 25, 26 of the other plate 3 and the curved elongated holes 21, 22 and 22, 24 partially overlap each other. The rod 41 is positioned between the two inner curved pieces 27, 28 so that the drill holes 42, 43 at both ends are aligned with the elongated holes 21, 22, 23, 24. Screws 46, 47 with their screw bolts 48, 49 are inserted from the outer sides of the curved pieces 25, 26 through the overlapping sections of the elongated holes 21, 22, 23, 24 and screwed into the internal threads 44, 45 in the drill holes 42, 43.

[0040] To facilitate the clamping of the curved pieces 25, 26, 27, 28, the screws 46, 47 have adjusting washers 50, 51 with a knurling 52, 53 on the outer circumference (cf. Fig. 5). The screws 46, 47, with their screw bolts 48, 49, are inserted through central bores 54, 55 of the adjusting discs 50, 51, and their screw heads 55, 56 engage positively in hexagonal recesses 57, 58 on the end faces of the adjusting discs 50, 51. By tightening the screws 46, 47, the overlapping curved pieces 25, 26, 27, 28 are clamped between the rod 41 and the screw heads 55, 56, whereby the hand grinder 1 is fixed in the adjusted pivoting position of the two plates 3, 4.

[0041] Sandpaper (e.g., a sanding disc) is applied to the front sides 7, 8 of the two plates 3, 4, and its edges are wrapped around the opposite edges 29, 30 of the two plates 3, 4. At the wrapped ends, the sandpaper has Velcro strips that connect to the Velcro strips 37, 38 on the backs 13, 14 of the two plates 3, 4 to secure the sandpaper to the plates 3, 4.

[0042] The hand sander 1 can then be used for sanding in the area of ​​a corner between two walls to which the angle between the two plates 3, 4 is set.

[0043] In order to change the pivoting position of the two plates 3, 4, the two screws 46, 47 can be loosened, the plates 3, 4 can be readjusted and then the adjusted pivoting position can be secured again by tightening the screws 46, 47.

[0044] The previously described hand sander 1 allows the angle between the panels 3, 4 to be adjusted within a range of 120° to 85°. Relative to the front sides of the panels 3, 4, this corresponds to an angle range of 240° to 275°. This hand sander 1 can be used in particular for sanding corners between a sloping roof and a jamb wall or a mezzanine floor, or between two walls at a 90° angle.

[0045] Plates 3, 4 according to Fig. 6 differ from the plates of the previously described hand grinder 1 in that the curved sections 25, 26, 27, 28 are shorter. As a result, the two plates 3, 4 are pivoted more closely together around the adjacent edges 5, 6 when the elongated holes 21, 22, 23, 24 in the curved sections 25, 26, 27, 28 of the various plates 3, 4 overlap each other.

[0046] Plates 3, 4 according to Fig. 6 can be mounted with the same rod 41 with handle 12 and with the same screws 46, 47 and adjusting washers 50, 51 as the plates 3, 4 according to Fig. 3. In this embodiment, the panels 3, 4 can be pivoted relative to each other within a range of 85° to 60°, which corresponds to an angle between the front sides of the panels 3, 4 of 275° to 300°. This hand sander can be used in particular for sanding corners in the gable area between adjacent roof slopes. List of reference symbols 1 hand grinder 2 angles 3, 4 plate 5, 6 edge 7, 8 flat front 9 Joint 10 axis 11 Locking device 12 Handle 13, 14 back 15,16 two pairs 17-20 Curve guidance 21-24 slot 25-28 arched piece 29, 30 edges 31.32 side edge 33, 34 bevel 35, 36 bevel 37, 38 Velcro strips 39 Velcro fastener 40 side bridge 41 rod 42, 43 borehole 44, 45 internal thread 46, 47 screw 48.49 screw bolts 50, 51 adjusting disc 52, 53 ribbing 54, 55 central hole 55.56 screw head 57, 58 Deepening 59, 60 Velcro strips

Claims

[1] Hand sander for sanding wall surfaces at corners between two walls comprising • two plates, each having two adjacent edges and a flat front surface for the attachment of a grinding wheel, • a joint by which the two plates are pivotally connected around an axis running along the two adjacent edges, • a locking device for locking the two plates in a set swivel position and • a handle located on the back of the two plates and connected to them to move the two plates along the surfaces to be sanded. [2] Hand grinder according to claim 1, in which the joint has at least one pair of curved guides, each with a curved elongated hole, wherein one curved guide of the pair is firmly connected to the back of one plate and the other curved guide of the pair is firmly connected to the back of the other plate, the centers of the radii of curvature of the curved elongated holes of the two curved guides fall into the adjacent edges of the two plates and an axle is inserted through the two curved elongated holes, which axle is connected at both ends to projections which can be clamped to the outer sides of the two curved guides via a clamping device in order to clamp them in the set pivot position. [3] A hand grinder according to claim 2, wherein the joint comprises two pairs of curved guides, the two pairs being connected to the two plates at a distance from each other and the axis extending through the curved slots of both pairs. [4] Hand grinder according to claim 2 or 3, wherein the curved guides are each formed by an arc piece which has a curved elongated hole and is connected at one end to one of the two plates. [5] A hand grinder according to any one of claims 2 to 4, wherein each plate is integrally connected to each cam guide connected thereto. [6] Hand grinder according to one of claims 2 to 5, in which the clamping device comprises the following features: a rod arranged between the two pairs of curved guides, at the ends of which the mutually facing curved guides of the two pairs rest, threaded bolts projecting from the two ends of the rod, which are each inserted through the elongated holes of the two curved guides of a pair and screw heads connected to the threaded bolts or nuts screwed onto the threaded bolts, which rest on the mutually facing curved guides of the two pairs. [7] Hand grinder according to claim 6, in which each threaded bolt is inserted through a central through-hole of an adjusting disc which has on one end face a hexagonal recess with the center on the center of the through-hole, which is formed complementary to the screw head or the nut, so that the recess forms a positive connection with the inserted screw head or the inserted nut. [8] Hand grinder according to claim 7, wherein the discs have a serration on the outer circumference. [9] A hand grinder according to any one of claims 6 to 8, wherein a handle projects radially outwardly from the rod. [10] Hand grinder according to one of claims 1 to 9, in which the two plates have bevels on the adjacent edges on the back sides. [11] Hand grinder according to one of claims 1 to 10, in which the plates have further bevels on the opposite edges on the rear sides. [12] Hand grinder according to one of claims 1 to 11, in which the adjacent edges of the two plates are longer than the edges of the two plates facing away from each other. [13] Hand grinder according to one of claims 1 to 12, in which the side edges of the two plates are bevelled or curved. [14] Hand grinder according to one of claims 1 to 13, in which the two plates each have a Velcro strip on the backs for forming a Velcro connection with a Velcro strip on a grinding wheel, which can be applied to the front sides of the two plates and folded around the edges of the two plates facing away from each other. [15] Hand grinder of any one of claims 1 to 14, which consists of plastic and / or metal.

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