GRINDING MACHINE

Abstract

The grinding machine (1), in particular for grinding and/or sharpening of knives, comprises a grinding disc (2), mounted rotatably around a turning axis (D1) and turnable in direction of rotation (D), with a cylindrically-shaped grinding surface (2a) comprising abrasive means, as well as comprising a guiding part (3), which is arranged immediately next to the grinding surface (2a) of the grinding disc (2), wherein the guiding part (3) has a guiding surface (3a) which extends in such a way that the guiding surface (3a), together with the grinding surface (2a), forms a gap (S), which progressively tapers in the direction opposite to the direction of rotation (D) and which runs parallel to the direction of the turning axis (D1), and that an overlay part (4) with an overlay surface (4a) running towards the gap (S) is arranged immediately next to the grinding surface (2a) of the grinding disc (2).

Description

FIELD OF THE INVENTION

The invention concerns a grinding machine.

BACKGROUND OF THE INVENTION

Many grinding machines and grinding apparati are known for grinding or for re-sharpening of cutting devices, such as knives, or rather, their blades. Such grinding machines have the disadvantage that it is difficult to sharpen a blade reproducibly evenly and that, in particular, this is difficult for people who have limited experience with respect to grinding. Thus, it is the problem which this invention seeks to solve to provide a more advantageous grinding machine.

SUMMARY OF THE INVENTION

In particular, the problem is solved by a grinding machine comprising a grinding wheel with a disc-shaped basic body, wherein the disc-shaped basic body has a centre of turning, as well as at least one side surface extending substantially perpendicularly to the centre of turning, and wherein a grinding disc, having a grinding layer is removably fixable to the disc-shaped basic body in such a way that the grinding disc is arranged concentrically with respect to the centre of turning and extensionally along the side surface of the disc-shaped basic body, as well as comprising a support device which forms a guide, wherein the guide is arranged to extend in such a way that at the grinding disc, when this is attached to the basic body, an acute angle γ is formed between the grinding layer and the guide, to form a grinding gap.

The grinding machine according to the invention has the advantage, amongst others, that easily-replaceable grinding discs are used as grinding means. In a particularly preferred embodiment, conventional grinding discs may be used which provides the advantage that such grinding discs are very cheap. Also grinding discs of varying grain size can be used.

In a particularly advantageous embodiment, the grinding disc is coupled elastically with the grinding wheel, in particularly in such a way that at least a section of the grinding disc is elastically movable in the direction of extension of the centre of turning, which provides the advantage that a blade that is to be ground lies particularly softly against the grinding disc, since the latter can adapt to the blade. This enables a particularly advantageous blade sharpening.

In a further advantageous embodiment a grinding disc is arranged on each side of a grinding wheel, such that each side of a blade has its own grinding disc available to it.

In a particularly advantageous embodiment, the grinding gap is arranged with respect to the centre of turning of the grinding disc such that the grinding disc moves predominantly from bottom to top or alternatively from top to bottom in the area of the grinding gap, which enables a particularly advantageous sharpening of a blade.

In a further advantageous embodiment, the support device has a rotatable support body, which has the advantage that a blade which is moved along the support device does not get scratched, and that the blade is particularly easily movable along the support device.

In the following, the invention is explained by means of an embodiment example.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 a perspective view of a grinding wheel;

FIG. 2 the grinding wheel shown in FIG. 1 in elevation;

FIG. 3 a longitudinal cross-section through the grinding wheel shown in FIGS. 1 and 2;

FIG. 4 a perspective view of a grinding wheel basic body;

FIG. 5 a perspective view of a grinding disc;

FIG. 6 a perspective view of a grinding machine from the front;

FIG. 7 the grinding machine shown in FIG. 6 in elevation;

FIG. 8 a detail view of the front of the grinding machine shown in FIG. 7;

FIG. 9 a further perspective view of the grinding machine from behind;

FIG. 10 a view of the rear side of the grinding machine;

FIG. 11 a view of the grinding machine from above, in partial cross-section;

FIG. 12 a support device in elevation;

FIG. 13 a cross-section through the support device shown in FIG. 12 along the line A-A;

FIG. 14 a perspective view of the support device;

FIG. 15 a longitudinal cross-section through a further embodiment of a grinding wheel.

DETAILED DESCRIPTION

FIG. 1 shows a grinding wheel 2 comprising a disc-shaped basic body 2a, which is fixedly connected with a driveshaft 2b, and which is rotatably mounted around a turning axis D, or alternatively, a centre of turning D of the basic body 2a. One grinding disc 3 is fixed on each of the sides of the basic body 2a, on the left side and on the right. The grinding disc arranged on the left side is shown fully visible and is firmly connected with the driveshaft 2b by means of an underlay disc 2e and a bolt 2f.

FIG. 2 shows the grinding wheel 2 shown in FIG. 1 in elevation, to which one grinding disc 3 is fixed on each of the two sides. In the depicted embodiment example, an elastic ring 2d is arranged between the basic body 2a and the grinding disc 3, in order to enable elastic mobility in the direction extending essentially in the direction of the turning axis D for sections of the grinding disc 3, in particular for sections arranged in the vicinity of the elastic ring 2d.

FIG. 3 shows a cross-sectional through the grinding wheel 2 shown in FIG. 2 along line B-B. The disc-shaped basic body 2a is firmly connected with the driveshaft 2b. The grinding wheel 2 has a side surface 2g, 2h on each side, in the outer end section of which, there is a groove extending circumferentially, in which an elastic means 2d, such as an elastic O-ring is held.

In the depicted embodiment example, the grinding disc 3 comprises an outer grinding disc part 3a with a grinding layer 3a and a preferably metallic fixation part 3b, which firmly fixed with the outer grinding disc part 3a. The fixation part 3b has a hole 3c in the middle. The grinding disc 3 can be formed in the most varied of ways such that it has a grinding layer 3a. For example, a plastic or a metal disc-shaped basic body could be used, onto which a grinding layer 3a has been put. The grinding layer 3a may, for example, have a plurality of grinding grains. The width of the usable grinding layer 3a may, for example, extend over a width 3d. In a preferred embodiment, the two grinding discs 3 are arranged, as shown in FIG. 3, such that they are firmly centrally held by an underlay disc 2e and a central bolt 2f, i.e., are firmly held at the fixation part 3b, as opposed to the grinding discs 3 which extend from the centre at a distance to the sides 2g, 2h and outwards lie against the elastic O-ring 2d. This embodiment has the advantage that, in particular, surfaces of at least section of the grinding layer 3a can yield in the direction of extension of the turning axis D, such that the surfaces of the grinding layer 3a behave relatively softly and, for instance, can adapt to a blade to be sharpened.

FIG. 4 shows a perspective view of the grinding wheel basic body 2a with side surfaces 2g, 2h and a central overlay 2i. On the right there is a grinding disc 3. At least side surface 2g, and when using two grinding discs, also side surface 2h, extends substantially perpendicularly to the turning axis D. ‘Substantially perpendicularly to the turning axis’ means, on the one hand, that, in a particularly preferred embodiment, the side surfaces 2g, 2h are perpendicular, i.e., exactly perpendicular, to the turning axis D. On the other hand, this means that in a further advantageous embodiment, the side surfaces 2g, 2h can also extend at a slight angle to the turning axis, such as, for example conically or crooked.

FIG. 5 shows a perspective view of a grinding disc 3 with grinding layer 3a, fixation part 3b and hole 3c. FIG. 5 also shows the preferred grinding area 3g, which extends between a horizontal line 3f that runs through the hole 3 and an upper horizontal line 3e, which preferably runs at a distance of about 1 cm to 2 cm away from the horizontal line 3f, such that the height 3h can preferably be up to 2 cm.

FIG. 6 shows a perspective view of an embodiment of a grinding machine 1. This comprises a rotatably-mounted grinding disc 3 with a grinding layer 3a, which is arranged in a housing 8 with a cover 7 and a front cover 9. A support device 5, 6 is arranged on the left and on the right, each of which is provided with a magnet 14. Also, there is a sideways guide 10. The grinding machine 1 is fixed to a ground plate 4 and comprises an extraction unit 12 via which air may be extracted from inside the housing 8.

FIG. 7 shows the grinding machine shown in FIG. 6 in elevation and FIG. 8 an enlargement of the elevation shown in FIG. 7. The support device 5 with guide 5a, shown on the left, as well as the grinding disc 3 with grinding layer 3a, arranged on the left, form a grinding gap S with opening angle γ, wherein the gap S at its bottom, ends in a gap line S1, as shown in FIG. 8. As shown in FIG. 7, the gap line preferably runs perpendicularly towards the rear. In mirrored arrangement to this, the support device 6 with guide 6a, shown on the right, as well as the grinding disc 3 with grinding layer 3a, arranged on the right, form a grinding gap S with opening angle γ and gap line S1. Since the grinding layer 3a can yield slightly in the direction of extension of the turning axis D, in particular in dependence on the force exerted on the grinding layer 3a by the blade to be sharpened, the opening angle γ and the gap line S1 can alter slightly, which allows particularly ‘soft’ grinding. The support devices 5, 6 can be arranged in a fixed manner. A blade to be sharpened can be laid into the grinding gap S and be moved to and fro in the direction of extension of the gap line S1, in order to sharpen the blade on the rotating grinding layer 3a. In a particularly preferred embodiment, the support devices 5, 6 are pivotally arranged in such a way that the opening angle γ may be adjusted and that the support devices 5, 6 can be fixed in the currently desired position. In a preferred embodiment, the adjustable opening angle γ is adjustable across a range of angles between 15° and 35°. In a preferred embodiment, the gap line S1 is arranged at a vertical distance from the centre of turning D of the driveshaft 2b by in the range of between 0 cm and 2 cm, preferably between 2 mm and 12 mm. This provides the advantage, as shown in FIG. 5, that the grinding layer 3a is moving predominantly in the vertical direction in the area of the gap line S1, since the grinding disc turns in direction R or counter to R, which, in particular, provides the advantage that only a small force is exerted acting in the direction of extension of the gap line S1. Due to this, the blade can be particularly easily ground with limited exertion of force.

FIG. 9 shows a perspective view of the grinding machine 1 and FIG. 10 from behind in elevation. FIG. 11 shows the grinding machine 1 from above, in partial cross-section. The grinding machine 1 comprising an adjustment device 11 with two rotatable mounted turning axes 11a, 11b, which are connected with the left or respectively the right support device 5, 6, in order to alter and adjust their presentation angle and therewith also the angle γ of the grinding gap S. The grinding machine 1 comprises a movably mounted slider 11h with longitudinal slot 11l as well as a locking screw 11i, which allows the slider 11h to be released and locked. The slider 11h is also connected with an adjustment grip 11e, wherein the adjustment grip 11e engages via a shaft in the longitudinal slot 11f, 11g of the levers 11c, 11d, and wherein the levers 11c, 11d are firmly connected at one end with an axis of turning 11a, 11b, such that pushing the adjustment grip 11e vertically results in a mirrored pivoting of the two axes of turning 11a, 11b and thereby also of the support devices 5, 6. The adjustment grip 11e can be locked with the help of the locking screw 11i, thereby also fixing the position of the support devices 5, 6. In an advantageous embodiment, there is an angle scale 11k arranged on the rear wall, wherein, based on the positioning of the slider 11h, the angle size γ of the grinding gap S may be read off and adjusted. In a further advantageous embodiment, the grinding machine 1 is firmly and releasably connectable with a ground plate 4 via a fixing screw 13.

FIG. 12 shows an embodiment example of a support device 5 in elevation. FIG. 13 shows a cross-section along line A-A shown in FIG. 12 and FIG. 14 a perspective view of the support device 5. The support device 5 comprises a basic body 5a with recesses 5b and releasably-arranged cylinder-shaped pegs 5c therein, on which rotatably-mounted support bodies 5d are arranged. In the shown embodiment example, the support bodies 5d take the form of hollow, cylindrical sleeves. The support bodies 5d can take on the most varied of forms, to facilitate a turning surface or guide 5e in the direction of extension of the gap line S1. In a particularly advantageous embodiment, a Magnet, preferably a permanent magnet, is arranged in the support device 5, 6, as shown in FIG. 13, such that a metallic, ferromagnetic blade is pulled against the support bodies 5d and lies against them advantageously. This embodiment has the advantage that the blade lies against the support device 5, 6 in a defined way, such that the blade which is to be sharpened is at a defined angle to the grinding layer 3a, which results in it being possible to grind the blade reproducibly with the same angle, even if the blade is only ground, for example, weekly or monthly. The rotatably-mounted support bodies 5d also have the advantage that the side of the blade that slides past the support bodies 5d does not get scratched or otherwise damaged.

FIG. 15 shows a longitudinal section that a further embodiment example of a grinding wheel 2. Differently to the grinding wheel 2 shown in FIG. 3, the grinding wheel 2 shown in FIG. 15 has an elastic means 2d stretching out over the whole width 3d of the grinding layer 3a and on which the grinding disc 3 can lie. Instead of being on the Grinding wheel 2, the elastic means 2d could also be arranged on the rear side of the grinding disc 3, in particularly in such a way that the elastic means 2d forms part of the grinding disc 3. This embodiment has the advantage that when a grinding disc 3 is replaced, so is the elastic means 2d, which is thereby as good as new after the replacement. This embodiment has the advantage that the elastic properties of whichever grinding disc 3 is used remain constant or very similar over the long-term. In a preferred embodiment, the grinding wheel 2 is formed such that a conventional and therefore very cheap grinding disc 3 can be used. In addition to this, grinding discs 3 of varying grains could be held in store, such that a grinding disc 3 of appropriate grain can be fixed to the grinding wheel 2 according to particular grinding requirements. The elastic means 2d could also be made of such a width in the radial direction that a majority or all of what is shown as a cavity in FIG. 15 is also filled with elastic means 2d. The elastic means 2d preferably consists of an elastic plastic. The elastic means 2d can be formed in a plurality of possible ways, for example as a spring, in particular as a leaf spring. Thus, for example, a disc-shaped leaf spring could be arranged immediately next to the grinding 3 and it could be, for example, secured on the shaft 2b immediately next to the grinding disc 2, wherein the disc-shaped leaf spring has springy properties in the direction of extension of the turning axis D, such that the grinding disc 3, which is arranged immediately next to the leaf spring, similarly has springy properties in the direction of extension of the turning axis D, due to the leaf spring.

Claims

1. A grinding machine (1), comprising a grinding wheel (2) with a disc-shaped basic body (2a), wherein the disc-shaped basic body (2a) has a centre of turning (D), as well as at least one side surface (2g) extending substantially perpendicularly to the centre of turning (D), and wherein a grinding disc (3), having a grinding layer (3a) is removably fixable to the disc-shaped basic body (2a) in such a way that the grinding disc (3) is arranged concentrically with respect to the centre of turning (D) and extensionally along the side surface (2g) of the disc-shaped basic body (2a), as well as comprising a support device (5, 6) which forms a guide (5e), wherein the guide (5e) is arranged to extend in such a way that at the grinding disc (3), when this is attached to the basic body (2a), an acute angle (γ) is formed between the grinding layer (3a) and the guide (5e), to form a grinding gap (S).

2. Grinding machine according to claim 1, characterised in that the basic body (2a) comprises an elastic carrier (2d) extending circumferentially and standing out from the side surface (2g), wherein the elastic carrier (2d) is of a matching form such that an attached grinding disc (3) lies against the elastic carrier (2d).

3. Grinding machine according to claim 2, characterised in that the elastic carrier (2d) is arranged towards the outer periphery of the disc-shaped basic body (2a).

4. Grinding machine according to claim 2, characterised in that the elastic carrier (2d) is an O-ring.

5. Grinding machine according to claim 1, characterised in that the basic body (2a) has an overly (2i) in the centre, which stands out from the side surface (2g) in the direction of extension of the centre of turning (D).

6. Grinding machine according to claim 1, characterised in that the grinding wheel (2) is formed on both sides for attaching a grinding disc (3).

7. Grinding machine according to claim 1, characterised in that the grinding gap (S) ends at its bottom in a gap line (S1), and that the grinding gap (S) is arranged in a range of between 0 cm to 2 cm, preferably between 2 mm and 12 mm, above a horizontal line (3f), wherein the horizontal line (3f) runs through the centre of turning (D).

8. Grinding machine according to claim 1, characterised in that the support device (5, 6) comprises a plurality of rotatably mounted support bodies (5d).

9. Grinding machine according to claim 8, characterised in that the support bodies (5d) are arranged next to each other in the direction of extension of the grinding gap (S).

10. Grinding machine according to claim 8, characterised in that the support means (5, 6) comprises a plurality of basic bodies (5a), which are arranged next to each other in the direction of extension of the gap (S), that the basic bodies (5a) are releasably connected with the support device (5, 6), and that at least one hollow, cylindrically-formed support body (5d) is rotatably mounted on each basic body (5a).

11. Grinding machine according to claim 8, characterised in that the support device (5, 6) is pivotally mounted about a turning axis (11a, 11b) which is substantially parallel to the direction of extension of the gap (S).

12. Grinding machine according to claim 11, characterised in that a support device (5, 6) is arranged on each side of the grinding wheel (2), and that the two support devices (5,6) are pivotally mounted in a mirrored fashion.

13. Grinding machine according to claim 11, characterised in that an adjustment device (11) is formed such that it allows a turning and locking of at least one turning axis (11a, 11b).

14. Grinding machine according to claim 13, characterised in that each of the turning axes (11a, 11b) are connected symmetrically with a shared linear slider (11h) via a lever (11c, 11d), such that a linear moving of the slider (11h) results in a equal but opposite pivoting of the turning axes (11a, 11b).

15. Grinding disc for a grinding machine according to claim 1.