WO2004037488A1

WO2004037488A1 - Sharpening device

Info

Publication number: WO2004037488A1
Application number: PCT/SE2003/001649
Authority: WO
Inventors: Thomas LÖFVENMARK
Original assignee: Loefvenmark Thomas
Priority date: 2002-10-23
Filing date: 2003-10-23
Publication date: 2004-05-06
Also published as: SE524407C2; SE0203149D0; SE0203149L; AU2003273124A1

Abstract

Sharpening device (EP, EP1, EP2) for sharpening of an edge (E) at a predetermined edge angle (α), comprising a clamping structure (1, 30, 230, 260) for fastening the device (EP, EP1, EP2) to a tool with an edge (2, 10), and an angle guide (3) arranged to control the angle of a whetter (4, 140). The device solves this by providing a support surface (5, 120) for the whetter (4, 140) at a distance (A) from and a height (H) the edge (E) that gives the desired edge angle (α). To allow sharpening of essentially all forms of tools with edges (2, 10), the position of the support surface (5, 120) is adjustable in the height direction (H) and in at least one additional direction in a plane (B-B) defining the edge angle (α).

Description

SHARPENING DEVICE

Field of the Invention

The present invention relates to a sharpening device and in particular a sharpening device for sharpening of an edge at a predetermined edge angle of the type comprising a fastening structure for attaching the device to a tool provided with an edge, and an angle guide arranged to control the angle of a whetter by providing a support surface for the whetter at a distance from and a height above the edge providing the desired angle.

Background of the invention

Today, there are a number of available sharpening apparatus, some having sharpening sticks arranged in X configuration, where the upper V shape forms the edge angle. A knife blade drawn through this V form gets both sides of the edge sharpened. This type of sharpening/ grinding apparatus is available in various shapes, but they all work according to the same principles. Only one fixed edge angle is provided.

Another type, are so called knife back clamping devices. Such devices are clamped to the back of the knife and extend a distance from the edge in the plane of the blade. A perpendicularly extending bar provided with a number of holes or slots is provided at the proximal end of the clamping device. A guide pin is entered through one of these holes, the guide pin is in turn attached to a whetter, and a fixed sharpening angle is provided by the height of the hole above the knife blade.

In general, clamping devices are comprised of two leg bars midways attached to each other by a screw. There exists a clearance between the leg bars, and the screw functions as a sort of axis there between. The back of a knife is arranged between the leg bars at one end and a screw pushes them away from each other at the other end. Thereby, the back of the knife is clamped between the bar legs. The perpendicular bar provided with holes (usually 4 to 6 holes) provides for fixed sharpening angles.

Examples of such clamping devices are found in US 4,471,951, US 4,538,382 and US 4,731,953.

However, this type of sharpening devices unfortunately leads to that, the resulting angle cannot be steplessly adjusted, the angle is dependent on the height of the knife blade, and that knifes lacking parallel surfaces at the neck cannot be sharpened. Furthermore, it is not possible to sharpen long knifes without moving the device along the neck of the knife, or sharpen other types of devices provided with an edge such as chisels, cutter blades or the like. Thus there exists a need for an enhanced sharpening device.

Summary of the invention

The present invention seeks to solve the problems associated with sharpening of devices provided with an edge, such as, knifes, chisels, cutter blades or the like. The basic aim with the present invention is met by the sharpening device of claim 1.

One advantage with such a device is that it can be used to grind and sharpen at all sharpening angles between 0 and 360 degrees, and that it provides for both horizontal and vertical pivotal adjustments.

Another advantage is that the device can be used to sharpen all types of tools or devices provided with an edge.

Still another advantage is that the angle guide is steplessly adjustable and is able to provide support for the whetter at all possible sharpening angles.

Advantageous embodiments of the invention are provided in the dependent claims. Short description of the figures

Fig.1 schematically shows the basic idea behind the present invention.

Fig. 2 shows an embodiment of a device according to the present invention attached to a knife.

Fig. 3 shows the device of fig. 1 partially in cross-section along the line c—c.

Fig. 4 shows an alternative embodiment of a device according to the present invention attached to a knife.

Fig. 5 shows the device of fig. 3 in cross-section along the line d — d.

Fig. 6 shows the device in an extended state.

Fig. 7 shows the device of fig. 5 in cross-section along the line d — d.

Fig. 8 shows the device of fig. 3 in an alternative extended state.

Detailed description of the invention

A first schematic embodiment of the invention is shown in fig. 1. This embodiment discloses a sharpening device EP for sharpening of an edge E with a predetermined edge angle α. Like the prior art sharpening devices, discussed above, the device EP according to the present invention comprises a fastening structure 1 for fastening the device to a tool 2 provided with an edge, and an angle guide 3 arranged to control the angle of a whetter 4 by providing a support surface 5 for the whetter 4 at a distance A and a height H from the edge E providing for the desired edge angle α. But contrary to the prior art sharpening devices, the device EP according to the present invention is so formed constituted that the position of the support surface 5 is adjustable in the height direction H and in at least one additional direction in the plane B-B defining the edge angle α without the need for releasing the device from the tool 2. The adjustment in the B-B plane can be provided by arranging the angle guide 3 on a means 6 that is moveable in relation to the fastening structure 1 of the device. This moveable means 6 is preferably comprised of one or more mutually lockable hinged or projectable arms/leg bars 1 and the angle guide 3 is thus arranged at the distal end of the means.

By moving the support surface 5 in the direction A, away from the edge E, knives with longer blades can be sharpened in one single sharpening step, without significantly affecting the edge angle α along the whole length of the edge E. Sharpening of long edges can alternatively be performed in two or more steps by moving the support surface 5 along the length of the edge E without moving the point of fastening with respect to the knife blade 2.

Moreover, the adjustment in the B — B plane makes it possible to sharpen almost any tool 2 provided with an edge, using the device according to the present invention. More in detail, this is achieved in that the fastening structure 1 is formed to be clamped onto the tool 2 in a number of different ways, e.g. at the back of the knife blade, transverse the direction of the blade of a chisel, around the handle/shaft of the tool etc. Detailed examples of fastening structures 1 are given in the description of specific embodiments below.

To better illustrate the device according the present invention, examples of two specific embodiments are described in detail below.

The following embodiments can be regarded as a complete sharpening system for tools provided with an edge, such as knifes, chisels and the like. The system is comprised of a number of parts that partially interact, partly may interact, partly are independent devices that cam be used independently.

The system as a whole manages to grind and sharpen all available tolls with an edge, such as: knives (independent of shape of the blade), chisels (all kinds including bendt gouges), woodcarving tools (all sorts), scissors, turning lathe tool (both metal and wood) etc.

The system is designed as one unity. From this unity, parts of the system may be brought when hunting or fishing for quick sharpening of e.g. knives. The whole system need not to be brought. This makes the system very flexible and easy to handle. To explain the different parts, the two embodiments of the present invention that separately and in combination makes up the system hereafter are referred to as EP 1 and 2 respectively.

EP 1: grind and sharpen knifes with all possible knife blade shapes.

EP 2: grind and sharpen all knifes with parallel blades, chisels (all sorts), woodcarving tools (all sorts).

Accessories: handle/ shaft clamp: round and flat

EP 1 + 2: grind and sharpen (in addition to the above) turning lathe tools both for wood and metal

EP shapening angle screw: A screw provided with a lying loop that is leaning 15 degrees in the forward direction. A guide pin that in turn is attached to a whetter is inserted in the loop. (M4 standard threads)

EP guide pin The EP guide pin is approximately 2 mm thick, 10 cm long and e.g. made of silver steel. At a first end there is provided a loop that prohibits that the guide pin slides through the loop of the sharpening angle screw. In the opposite end there is provided a 5 mm long M3 screw. This screw is screwed into a short end of a whetter.

EP whetter s: All available types of whetters are provided, both with respect to material and shapes such as triangular, quadratic, rectangular, round etc. whetters of different sizes. The guide pin is screwed into a specially shaped fastening structure on the short end of these whetters. W

EP normal whetter: The normal EP whetter is a triangular whetter with 13 mm wide sides and 70 mm long. Two of the sides are provided with diamond whetters of different grain size, fine and super fine. The third side is a very fine ceramic whetter for polishing.

More detailed description of the above components:

EP 1:

EP 1 shown in figs. 2 and 3 is a shaft holding' device. Hence, EP 1 is attached to the sides of a knife shaft 10 and is clamped thereon by a clamping screw 20. The components in the clamping device are hereafter referred to as vise 30. The vise comprises an upright screw holder 50 secured at a first end of a leg bar EPIA, with a clamping screw 55 and a counter part 60 that is detachably/ moveably attached to leg bar EPIA. A first end of a leg bar EPIB is, in one plane, pivotally arranged at the other end of the leg bar EPIA, and a leg bar EPIC is, in one plane, pivotally arranged at the other end of the leg bar EPIB. Thus the leg bars EPIB and EPIC can be folded out, and by lock knobs 90 and 100, respectively, be locked in the desired position. In the other end of leg bar EPIC there is provided a threaded hole 110, arranged to receive a sharpening angle screw 120.

By the use of a guide pin 130 attached to a whetter 140 and which is provided in and guided by the loop ofthe sharpening angle screw 120, the desired sharpening angle can be controlled by rising or lowering (by turning the screw) the sharpening angle screw 120 in the leg bar EPIC. When the other side of the knife is to be sharpened, the knife 10 is detached from the vise 30, turned around and reclamped. Alternatively, the sharpening angle screw 120 is moved so that it protrudes from the opposite side of the bar leg EPIC. All parts of EP 1 can be attached to each other when the devise is not in use.

EP 2:

EP 2 is a sharpening device of the type referred to as a knife-back clamping device with two knife-back clamping structures and a number of additional clamping functions in between the three leg bars. EP 2 is shown in figs 4 to 8 and comprises three leg bars, hereafter referred to as EP2A, EP2B and EP2C, respectively. The first two, EP2A and EP2B, are approximately 90 mm long and the third, EP2C, approximately 60 mm. at one end of EP2A there is provided a threaded hole 200, arranged to receive a sharpening angle screw 120that extends through holes 210 and 220 formed in the bar legs EP2B and EP2C, respectively. At the other end there is provided a first knife back clamping structure 230 formed between bar leg EP2A and EP2B. This first knife back clamping structure has a knife back receiving slit 240, which preferably is tilted 2.5 degrees upwards, whereby even small blades of folding knifes can be sharpened.

A knife blade 10 is placed in slot of the knife back clamping structure 230. A clamping screw 250 is tightened, which implies that the bar legs EP2A and EP2B are drawn towards each other. The sharpening angle is adjusted by screwing the sharpening angle screw 120 to the desired position. The whetter 140 is attached to the guide pin 130 and the sharpening device is ready to use.

To allow sharpening of long knifes, with knife blades exceeding approximately 15 cm, a second knife back clamping structure 260, located "under" the sharpening angle screw, is utilized (see figs. 6 to 8). In this case the bar leg EP2A is folded out by releasing the clamping screw 250, whereby the sharpening angle screw is able to be removed from the holes 210 and 220 in the lower bar legs EP2B and EP2C, respectively. The bar leg EP2A is locked by the clamping screw 250 in the folded out position.

A knife blade 10 is placed in the second knife back clamping structure 260 and a clamping screw 270 is tightened to lock the knife 10 in position. The guide pin 130 is joined with an extension pin 280 that in turn is screwed into the short end of the whetter 140. By use of the extended guide pin 130, EP 2 handles grinding and sharpening of knifes 10 up to the size of a machete. The guide pin 130 and the extension pin 280 are provided with threaded ends, and are screwed together to extend the guide pin, or are screwed into the whetter.

This can be done in two different ways:

1: (figs. 6 and 7) by locking the bar leg EP2A in a position where it acts as an extension of the bar legs EP2B and EP2C, whereby the bar legs forms a straight line. W 20

8

2: (fig. 8) by locking the bar leg EP2A at an angle (preferably between 90 and 180 degrees) with respect to the other bar legs EP2B and EP2C, whereby half the knife blade is sharpened. Then bar leg EP2A is folded to the corresponding angle on the opposite side with respect to the other bar legs EP2B and EP2C, and is locked in this position enabling sharpening of the other half of the knife blade.

Further, there is provided a parallelization screw 290 in the bar leg EP2C. By the parallelization screw 290, the bar legs EP2A, EP2B and EP2C can be lifted in a parallel fashion so that also thicker tools can be clamped by the knife back clamping structures or in between the bar legs EP2A, EP2B and EP2C. The parallelization screw 290 is a screw with a turning wheel. There are two threaded holes 300 and 310, respectively, in bar leg EP2C. When the parallelization screw 290 is screwed into the threaded hole 310 it reaches the lower surface of and lifts bar leg EP2B. Thence the clamping function between bar legs EP2B and EP2C can be parallelized in the range 0 - 12.5 mm. When parallelization is desired between bar legs EP2A and EP2B, the parallelization screw 290 is screwed into the threaded hole 300 in the bar leg EP2C. The parallelization screw 290 passes through bar leg EP2B via a hole 320, reaches the lower surface of and lifts bar leg EP2A. Even for this case, parallelization up to 12.5 mm can be achieved. The parallelization screw 290 can also be used to increase the clamping force in the clamping function of the two knife back clamping structures.

EP 2 can sharpen all types of chisels by clamping the blade between bar legs EP2B and EP2C (not in the knife back clamping structure, but between the bar legs) at a distance from the edge. By turning the bar leg backwards (towards the shaft of the chisel) and rising the sharpening angle screw 120, the desired angle is achieved for the chisel.

Furthermore, EP2 can be used to sharpen razor-blades, which are inserted between bar leg EP2A and EP2B all the way to the threads of the clamping screw 250, where it is clamped. By lowering the sharpening angle screw 120 to the lowest position, the razor-blade can be sharpened. There are a large number of tools that are provided with a cutting edge, the shapes of which are uncountable. It is impossible to herein describe each type of tool, how it is clamped and sharpened. There are a large number of clamping possibilities between the bar legs EP2A, EP2B and EP2C. By folding out the bar leg EP2A and by rising or lowering the sharpening angle screw 120 there is always provided a way to sharpen a tool provided with an edge, sharpening angle screw 120. Through use of different whetters (provided as accessories) all types of tools with an edge can be sharpened, as well as all types of edges.

EP 1 and 2:

EP 1 can be assembled into one unit with EP2 together with guide pins 130 and whetter 140. All parts are connected to each other when not in use, and it may be carried along in a pocket. This feature has been one of the goals during the design work

By dismounting the counter hold 60 from EP 1 and attaching it to bar leg EP2A (in the folded out position), and attaching the bar legs EPIB and EPIC to the counter hold 60 via one of the two threaded holes therein (not shown), vertically arranged bar legs are provided, which moreover are pivotal by pivoting the bar leg EP2A. By arranging the bar legs in desired positions and performing fine adjustments using the sharpening angle screw 120 a new dimension of available sharpening angles is provided. Using this combination, e.g. lathe tools can be sharpened at 90 degree angle, edges can be sharpened from the front, both sides of knifes can be sharpened from the front, etc. The possibilities are enormous.

EP accessories:

There are provided two types of shaft holders for the EP 2, so that EP 2 also can handle triangular knife blades. A "flat" shaft holder comprised of two bar legs that are forced together by two through-screws at their ends. A knife shaft is inserted between the bar legs, which are screwed together against the knife shaft. The lower bar leg is longer than the upper. The end of the lower bar leg is clamped in between the bar legs EP2B and EP2C of EP2. EP 2 now serves as pivotal bar legs for this shaft holder. A round shaft holder is comprised of a 45 mm round ring provided with 4 clamping screws, wherein a shaft can be inserted and centred by the four clamping screws. Even non symmetric shafts can be clamped. A bar leg extends from the ring. The end of the bar leg is clamped in between the bar legs EP2B and EP2C in the same manner as with the flat shaft holder.

With these two shaft holders and the vise, all types of shafts can be firmly clamped by the system according to the present invention.

By these different possibilities of modifying EPl and EP2, the system can be utilized to grind and sharpen at all sharpening angles from 0 to 360 degrees, while at the same time preserving the flexible adjustment of the sharpening angle through the pivotal adjusting possibilities both horizontal and vertical. The system can therefore be used to grind and sharpen all types of tools provided with an edge.

According to one embodiment, a triangular whetter with three different grain size on the three sides, two sides provided with diamond whetters with fine and super fine grain size, respectively and the third side provided with a very fine ceramic whetter for polishing of the edge after sharpening.

Claims

Sharpening device (EP, EPl, EP2) for sharpening of an edge (E) at a predetermined edge angle ( ), comprising a clamping structure (1, 30, 230, 260) for fastening the device (EP, EPl, EP2) to a tool with an edge (2, 10), and an angle guide (3) arranged to control the angle of a whetter (4,140) by providing a support surface (5, 120) for the whetter (4,140) at a distance (A) from and a height (H) above the edge (E) that gives the desired edge angle (α) characterized in that the position of the support surface (5, 120) is adjustable in the height direction (H) and in at least one additional direction in a plane (B-B) defining the edge angle (α).

Device (EPl, EP2) according to claim 1 characterized in that the clamping structure (30, 230, 260) is of vise type.

Device (EPl, EP2) according to claim 2 characterized in that

the clamping structure (30, 230, 260) comprises an upright screw holder (50) secured at a first end of a leg bar EPIA, with a clamping screw (55) and a counter part (60) that is detachably/ moveably attached to leg bar EPIA.

Device (EPl, EP2) according to claim 3 characterized in that

a first end of a leg bar EPIB is, in one plane, pivotally arranged at the other end of the leg bar EPIA,

a leg bar EPIC is, in one plane, pivotally arranged at the other end of the leg bar EPIB, and

an angle guide in the form of a sharpening angle screw (120) is arranged in a threaded hole (110) in the other end of the bar leg EPIC, whereby the adjustments of the position of the support surface is provided by pivotal movement of the bar legs EPIB and EPIC with respect to the bar leg EPIA and screwing the sharpening angle screw (120).

Device (EPl, EP2) according to claim 1 characterized in that

the clamping structure (30, 230, 260) is a knife back clamping structure.

Device (EPl, EP2) according to claim 5 characterized in that

the knife back clamping structure (260) is formed at a first end of two bar legs EP2B and EP2C,

a first end of a third bar leg EP2A is, in one plane, pivotally arranged at the other end of any one of the leg bars EP2B and EP2C, and

an angle guide in the form of a sharpening angle screw (120) is arranged in a threaded hole (200) in the other end of the bar leg EP2A, whereby the adjustments of the position of the support surface is provided by pivotal movement of the bar leg EP2A with respect to the bar legs EP2B and EP2C, and screwing the sharpening angle screw (120).

Device (EPl, EP2) according to claim 6 characterized in that it comprises an additional knife back clamping structure (230) formed between the bar legs EP2A and EP2B when the bar leg EP2A is in folded in state.