DE29704759U1 - Device for manually sharpening cutting edges of cutting tools - Google Patents

Description

Applicant: Karl Liedschreiber
St-Martin-Str. 9
86647 Pfaffenhofen

Device for manual sharpening of cutting edges of Cutting tools

The invention relates to a device for manually sharpening cutting edges of cutting tools, in particular manually operated cutting tools such as knives, scissors, etc.

The well-known hand sharpeners are not user-friendly and only allow for inaccurate sharpening.

Based on this, it is therefore the object of the present invention to create a hand-held sharpening device that is easy and precise to operate and at the same time is as universally usable as possible.

The solution to this problem consists in a device of the type mentioned above with a shaft-shaped support body which has at least one fork-shaped end with two V-shaped inner flanks inclined towards each other.

edge projections and a tongue-shaped

Tool arrangement which contains a sharpening tool with parallel side edges made of hard metal and a guide head which delimits the sharpening tool at the end remote from the support body and has side flanks parallel to the adjacent inner flanks of the edge projections, wherein at least the guide head is displaceable in the longitudinal direction of the tool arrangement.

With the help of this movable guide head, the clear width of the insertion gap between the guide head and the lateral edge projections and thus the desired sharpening angle can be set in an advantageous manner. The workpiece to be sharpened is in a reliable, one-sided position during the sharpening process, i.e. while it is being pulled through the gap mentioned, which ensures that the angle remains constant.

Advantageous embodiments and appropriate further developments of the higher-level measures are specified in the subclaims. The tool arrangement can advantageously contain a hard metal bar forming the sharpening tool and can be arranged in the support body so that it can be continuously adjusted in the longitudinal direction. The hard metal bar forming the sharpening tool forms a simple and inexpensive insert which, when a

The side edge area can be easily moved so that a new, unused side edge area is available. This ensures that the side edges of the sharpening tool that come into contact with the workpiece to be sharpened can be used almost along their entire length. Since the hard metal has a long service life and the bar-shaped sharpening tool can be used practically along its entire length, this results in a long overall service life. The sharpening tool can then simply be replaced with a new one. The measures mentioned above therefore result in excellent cost-effectiveness.

A further advantageous embodiment can consist in the tongue-shaped tool arrangement being designed as a double slide arrangement, which comprises the hard metal bar forming the sharpening tool and a receiving tab spanning this and carrying the guide head, and which engages with its rear end in a stiffly movable manner in an associated insertion recess in the carrier. The guide head and the sharpening tool can be moved independently of one another and relative to one another. This ensures that neither the complete use of the entire length of the sharpening tool nor the exact setting of the sharpening angle have a negative influence on one another.

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The support body can advantageously be provided with a support tongue arranged between the lateral projections, on which the sharpening tool rests. This measure results in particularly high stability.

In a further advantageous embodiment, the support bracket can contain a bed assigned to the sharpening tool, limited by stops, the length of which is greater than the length of the sharpening tool. This ensures that the sharpening tool can be adjusted using the support bracket carrying the guide head, which ensures a high level of user-friendliness.

The insertion recess associated with the tool arrangement can be designed as a through-recess that is open on both sides. This makes it possible to drive the tool arrangement out of the insertion recess by inserting a pushing tool from the back, which also has a beneficial effect on user-friendliness.

A further useful measure can be that the support body preferably has a receiving device for a pulling element with a pulling surface in the area behind its fork-shaped end. This makes it possible to remove the

To give the cutting edge a fine grinding etc., which is sometimes desirable.

Another particularly preferable development can consist in the support body containing a bar-shaped sharpening tool in the area of one end, which is accommodated in the area of a support side flank and to which a pivoting workpiece system that projects beyond its working surface is assigned. This further increases the variety of uses. The free accessibility of the working surface of the sharpening tool and the pivoting workpiece system advantageously enable precise sharpening of angle-related cutting edges, such as those found on scissors, vegetable slicers, lawn mowers, etc.

The workpiece system can advantageously be provided with an operating lever opposite its pivot bearing, which is expediently designed as an extension of a bearing flange and advantageously has a plate-shaped recess. The plate-shaped recess enables the operator to place a thumb or other finger, which makes it easier to adjust the workpiece stop and in particular ensures that the operating lever can be held in place by pressure in engagement with a ratchet on the support body side, which ensures reliable operation in any angular position of the workpiece stop.

Fixation results. An indexing device can be assigned to selected angles.

Another particularly useful measure can be that the swivel range of the workpiece system is limited by end stops arranged on both sides of the swivel axis, whereby an end stop that engages behind the workpiece system can have an inwardly curved rear side. This advantageously functions as a support surface against which an operator can press a finger or thumb without the risk of slipping.

Further advantageous embodiments and appropriate further developments of the overarching measures are specified in the remaining subclaims and can be taken from the example description below.

A preferred embodiment of the invention is explained in more detail below with reference to the drawing.

Figure 1 is a perspective view of a hand sharpener according to the invention,

Figure 2 is an enlarged plan view of the fork-shaped

End area of the hand sharpener according to the invention,

Figure 3 is a section along the line III/III in Figure 2,

Figure 4 is an enlarged plan view of the

end region of the hand-held sharpening device according to the invention provided with a pivotable workpiece support,

Figure 5 is a front view of the component containing the pivotable workpiece system and

Figure 6 is a side view of the pivoting
Component containing the workpiece system.

The hand-held sharpening device on which the drawing is based consists, as can best be seen in Figure 1, of a shaft-shaped support body 1 designed as a handle, which has a sharpening head 2 or 3 at each of its two ends, whereby one sharpening head 2, shown here on the left, is primarily intended for sharpening blades such as knife blades, and the other sharpening head 3, shown here on the right, is primarily intended for sharpening angle-related cutting edges such as the cutting edges of scissor blades, lawn mowers, vegetable slicers, etc.

The end of the support body 1 associated with the sharpening head 2 intended for sharpening blades is fork-shaped, as shown in Figures 1 and 2. Accordingly, two rope-shaped edge projections 4 are provided, which have V-shaped, mutually inclined edges.

Have inner flanks 5. The edge projections 4 flank a central tongue projection, visible in Figure 3, which is formed on the support body 1 and serves as a support tongue 6 for a tongue-shaped tool arrangement 7 protruding into the niche between the edge projections 4. This comprises a bar-shaped sharpening tool 8 resting on the support tongue 6, which is formed here by a bar-shaped hard metal piece, and a guide head 9 which receives the end of the sharpening tool 8 remote from the support body.

The hard metal bar forming the sharpening tool 8 has, as shown in Figure 2, exposed, parallel side edges along which the blade to be sharpened is pulled. It would therefore also be conceivable to provide a tongue part made of plastic, etc., which is only covered with lateral hard metal strips, instead of a solid piece of hard metal. The active area of the side edges 10 is, as shown in Figure 2, limited by the guide head 9. This has side flanks 11 parallel to the inner flank 5 of the adjacent edge projection 4, which project laterally over the exposed side edges 10 of the sharpening tool 8 and, together with the adjacent inner flank 5, each define an insertion gap 12 into which the blade to be sharpened is inserted.

The guide head 9 is infinitely adjustable in the longitudinal direction of the tongue-shaped tool arrangement, i.e. it can be more or

less into or out of the space between the edge projections 4, as indicated in Figures 2 and 3 with broken lines. This allows the clear width of the gap 12 to be changed, as indicated in Figure 2 at d or d'. The further the guide head 9 is moved out of the area between the edge projections 4, the larger the clear width of the gap 12 becomes. At the same time, the exposed area of the side edges 10 of the bar-shaped sharpening tool 8 is also extended. The further the guide head 9 is moved out of the area between the edge projections 4, the thicker the blade to be sharpened can be, or the more a blade that is weaker than the clear width of the gap 12 can be tilted, which allows the achievable cutting angle to be adjusted.

The bar-shaped sharpening tool 8 is also arranged so that it can be adjusted in the longitudinal direction, so that gradually several length sections of the side edges 10 can be brought into the position required during the sharpening process. If a point is worn, the bar-shaped sharpening tool is simply moved so that a new, unused point is available. If the guide head-side half of the bar-shaped sharpening tool 8 is worn, it can be turned, whereby the initially opposite, in one of the tool arrangement 7

The half engaging in the insertion recess 13 of the support body 1 can be used.

It would be conceivable to arrange the guide head 9 firmly on the bar-shaped sharpening tool 8. In this case, the guide head 9 would be adjusted with the sharpening tool 8.

In the example shown, the guide head 9 can be moved independently of the bar-shaped sharpening tool 8 and vice versa. Accordingly, the guide head 9 is attached to the end of a receiving tab 14 resting on the bar-shaped sharpening tool 8 and not covering its side edges 10. The bar-shaped sharpening tool 8 and the receiving tab 14 form a double slide arrangement, the rear end of which engages in the aforementioned insertion recess 13 of the support body 1. In order to ensure a reliable hold, a clamping fit is provided. The insertion recess 13 is in any case long enough that both parts, i.e. the sharpening tool 8 and the receiving tab 14 with the guide head 9, can be independently and continuously adjusted within the desired range.

In order to achieve a compact design, the receiving bracket 14 is provided with a bed 16 assigned to the sharpening tool 8 and delimited by front and rear stops 15, into which the bar-shaped sharpening tool 8 can be inserted. The length of the bed 16 is greater than the length of the bar-shaped

Sharpening tool 8 so that the desired mutual displacement is guaranteed. The excess length of the bed 16 is dimensioned such that the bar-shaped sharpening tool does not come out of engagement with the guide head 9 even if its rear edge rests on the rear stop 15 of the receiving tab 14. If the sharpening tool already rests on the rear stop 15 with its rear edge and the guide head 9 is nevertheless to be adjusted further outwards, the bar-shaped sharpening tool 8 is adjusted as well.

In the example shown, the support body 1 is provided with an opening 17 running transversely to the rear end of the insertion recess 13. This ensures that the insertion recess 13 is accessible from behind via the opening 17. It is therefore possible to insert a pin etc. into the insertion recess 13 from behind to drive out the double slide arrangement consisting of the sharpening tool 8 and the receiving tab 14 with the guide head 9. The double slide arrangement mentioned can therefore be arranged with a tight clamp fit. The guide head 9 is provided at its front end, as shown in Figure 4, with a notch 18 that is open at the bottom, to which a tool for moving the receiving tab 14 with the guide head 9 or the entire double slide arrangement can also be attached and which accordingly also serves as an operating aid.

The cutting edges of knife blades that are guided past the free side edges 10 of the sharpening tool 8 formed by a hard metal bar are sharpened by cutting. In some cases, it can be useful to subsequently grind off the cutting edge that has been sharpened in this way. To make this possible, a basin-shaped recess 19 is provided on the top of the support body 1 in the area behind its fork-shaped end, into which a grinding stone with a grinding surface or a piece of sandpaper or sanding cloth can be inserted. The fastening can be permanent, for example by means of an adhesive connection, or detachable, for example by means of a clamping device or a Velcro connection.

In the area of the end associated with the sharpening head 3, the support body 1, as shown in Figures 1 and 4, is provided with a lateral edge niche 20, which has a boundary running in the direction of the associated side flank 21 and a boundary running transversely thereto. A bar-shaped sharpening tool 22 rests on the boundary of the edge niche 20 running in the direction of the side flank 21. This is designed here as the upper flange of a hard metal piece 23 with a T-shaped cross section, which engages with its web in the support body 1. The hard metal piece can be injected into the support body 1, which is expediently designed as a plastic injection molding, or can be arranged so that it can be exchanged.

The exposed working surface of the bar-shaped sharpening tool 22 facing the edge niche 20 is overhung by a workpiece support 24 which can be pivoted about an axis parallel to the upper working surface of the sharpening tool 22 for the exact adjustment of the inclination of the workpiece to be sharpened and thus for the exact maintenance of the inclination of the cutting surface, as indicated in Figure 4 with broken lines. The pivoting range of the workpiece support 24 can extend at least 30° outwards from the position perpendicular to the working surface of the sharpening tool 22 indicated in Figure 4 with broken lines, so that an obtuse angle of at least 120° is obtained. To reduce wear and thus to achieve high precision over a long service life, the workpiece support 24 is provided with a metal insert 32 in the area of the support surface.

The boundary of the edge niche 20, which runs transversely to the working surface of the sharpening tool 22, serves as an end stop 25 for the workpiece system 24 in the end position forming an obtuse angle with the working surface of the sharpening tool 22. The rear side 26 of the end stop 25, which faces away from the workpiece stop 24, is curved inwards. This creates a logical support surface onto which an operator can press a finger or thumb without there being a risk of slipping.

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The workpiece system 24 is, as can be seen from Figure 5, provided with two parallel bearing flanges 27, which are provided with inwardly projecting bearing stubs 28, which, when assembled, can be snapped into associated bearing recesses of the support body 1 encompassed by the bearing flanges 27. One of the bearing flanges 27 is extended beyond the axis area to form an actuating lever 29. To facilitate handling, this actuating lever is widened in a disk shape and is provided on its outside with a plate-shaped recess 30, into which the operator can engage with a thumb, etc. In the area of the edge of the actuating lever 29, as can best be seen from Figure 6, a ratchet 31 formed by a ribbing is provided, which can be held for engagement with a counter-ratchet provided in the area of the opposite surface of the support body 1.

Preferred positions of the workpiece system 24 can be indexed by means of an indexing device. In the example shown, a bearing stub 28 is provided with a beard-shaped projection 34, to which one or more indexing recesses on the support body side are assigned. In the example shown, only the right-angled position of the workpiece system 24, indicated in broken lines in Figure 4, is indexed in this way. Outside of this, the beard 34 and the equally high, assigned bearing stub 28 are not engaged with the recesses on the support body side. The fixation of the set

The position is set by means of the locking mechanism 31, which is held by hand in engagement with the associated counter-locking mechanism on the support body side. To do this, pressure is exerted on the disk-shaped actuating lever 29, which is facilitated by the plate-shaped recess 30, into which a thumb can be inserted.

The support body 1, which, as mentioned above, is expediently manufactured as an injection-molded plastic part, can be provided with a molded-on eyelet so that it can be hung on a nail when not in use. In the example shown, the support body 1 is provided with an opening in the area of the sharpening head 3 that forms an eyelet 33. In the area of this opening, the web of the hard metal piece 23, which is T-shaped in cross section, also appears, which makes it possible to push it out of its seat using a tool in the case of an exchangeable attachment.

Claims (23)

Expectations 1. Device for manual sharpening of cutting edges of cutting tools, in particular manually operable cutting tools, with a shaft-shaped support body (1) which has at least one fork-shaped end with two edge projections (4) having inner flanks (5) inclined towards one another in a V-shape, and which carries a tongue-shaped tool arrangement (7) arranged between the edge projections (4), which contains a sharpening tool (8) with parallel side edges (10) made of hard metal and a guide head (9) which delimits the sharpening tool (8) at the end remote from the support body and has side flanks (11) parallel to the respectively adjacent inner flanks [5] of the edge projections [4] , wherein at least the guide head (9) is displaceable in the longitudinal direction of the tool arrangement (7). 2. Device according to claim 1, characterized in that the sharpening tool (8) is designed as a bar-shaped hard metal piece. 3. Device according to one of the preceding claims, characterized in that the sharpening tool (8) is arranged in the support body (1) so as to be adjustable in the longitudinal direction. 4. Device according to one of the preceding claims, characterized in that the guide head (9) is displaceable relative to the associated sharpening tool (8). 5. Device according to one of the preceding claims, characterized in that the tool arrangement (7) is designed as a double slide arrangement which comprises the bar-shaped sharpening tool (8) and a receiving tab (14) spanning the latter and carrying the guide head (9) and which engages with its rear end in a stiffly displaceable manner in an associated insertion recess (13) of the support body (1). 6. Device according to one of the preceding claims, characterized in that the support body (1) is provided with a support tongue (6) arranged between the lateral edge projections (4), on which the hard metal bar forming the bar-shaped sharpening tool (8) rests. 7. Device according to one of the preceding claims 5 or 6, characterized in that the receiving tab (14) contains a bed (16) assigned to the bar-shaped sharpening tool (8), delimited by stops (15), the length of which is greater than the length of the bar-shaped sharpening tool (8). 8. Device according to one of the preceding claims, characterized in that the insertion recess (13) is designed as a through recess open on both sides. 9. Device according to one of the preceding claims, characterized in that the guide head (9) is provided with a grip notch (18). 10. Device according to one of the preceding claims, characterized in that the support body (1) has, in the region behind its fork-shaped end, a receiving device (19) for a stripping element having a stripping surface. 11. Device according to one of the preceding claims, characterized in that the support body (1) contains in the region of one end a bar-shaped sharpening tool (22) arranged in the region of a side flank, to which a pivotably arranged workpiece system (24) projecting above its working surface is assigned. 12. Device according to claim 11, characterized in that the sharpening tool (22) is designed as a flange of a hard metal profile piece (23) with a T-shaped cross section, which engages with its web in the support body (1). 13. Device according to claim 11 or 12, characterized in that the workpiece support (24) is provided with two bearing flanges (27) which receive the support body (1) between them and are provided with inwardly projecting bearing stubs (28) engaging in bearing bores on the support body side. 14. Device according to one of the preceding claims 11 to 13, characterized in that at least one bearing flange (27) has a preferably disc-shaped widened extension (29) which functions as an actuating lever. 15. Device according to claim 14, characterized in that the extension (29) of a bearing flange (27) acting as an actuating lever is provided with a plate-shaped recess (30) in its surface. 16. Device according to one of claims 14 or 15, characterized in that the extension (29) of a bearing flange (27) acting as an actuating lever has a locking mechanism (31) in the region of its edge remote from the workpiece, which can be held in engagement with a counter-locking mechanism on the support body side. 17. Device according to one of the preceding claims 11 to 16, characterized in that the workpiece support (24) can be fixed in preferred positions by means of an indexing device (34). 18. Device according to one of the preceding claims 11 to 17, characterized in that the pivoting range of the workpiece support (24) is limited by end stops arranged on both sides of the pivot axis, wherein an end stop (25) is provided which engages behind the workpiece support (24) and has an inwardly curved rear side (26). 19. Device according to one of the preceding claims 11 to 18, characterized in that the Workpiece system (24) is provided with a metal insert (32) forming its contact surface. 20. Device according to one of the preceding claims 11 to 19, characterized in that the bar-shaped sharpening tool (22) is assigned an edge niche (20) which is delimited by the stop (25) on the side facing away from the end of the support body (1). 21. Device according to one of the preceding claims, characterized in that the support body (1) is provided, preferably in the region of one end, with an opening forming an eyelet (33). 22. Device according to one of the preceding claims, characterized in that the supporting body (1) is designed as an injection-molded part made of plastic. 23. Device according to one of the preceding claims, characterized in that the shaft-shaped support body (1) has different sharpening heads (2 and 3 respectively) in the region of its two ends, one sharpening head (2) being designed for sharpening blades and one sharpening head (3) being designed for sharpening angle-bound cutting edges.