WO2012153045A1

WO2012153045A1 - Improvement to appliances for sharpening the blades of cutting tools

Info

Publication number: WO2012153045A1
Application number: PCT/FR2012/050991
Authority: WO
Inventors: Jean-Pierre Bodard
Original assignee: Bobet Materiel
Priority date: 2011-05-06
Filing date: 2012-05-03
Publication date: 2012-11-15
Also published as: FR2974748B1; ES2539613T3; FR2974748A1; EP2704877B1; PL2704877T3; EP2704877A1

Abstract

The present invention relates to an appliance for sharpening the blades of cutting tools, including a plate (1) delimited by a front surface (10), a back surface (11), an upper end (12), a lower end (13), and two lateral sides (14, 15). Said plate (1) is provided with an opening (2), in communication with said upper end (12), for the tool blade to pass therethrough, wherein two sharpening structures, provided in the form of hinged elongate prongs (8, 9) so as to obtain a mobile sharpening V under pressure from the blade to be sharpened, are provided opposite said opening (2). The lower end (13) of said plate (1) is extended, on the back surface (11) thereof, by an intermediate slat (16), which is in turn extended by a gripping lug (17) extending in a plane (P') which is parallel or substantially parallel to said plane (P) of said plate (1), and which is offset with respect to said plane (P) on said back surface (11) of said plate (1). The intermediate slat (16) is delimited by a front edge (18), a back edge (19), and two side edges (20), each of which is extended by a lateral lug (22). Furthermore, said plate (1), said intermediate slat (16), said mounting tab (17) and said lateral lugs (22) are integrally produced from a cut and bent metal sheet.

Description

IMPROVING DEVICES TO AFFILIATE TOOLS OF SHARP TOOLS

The present invention relates to apparatus for sharpening the blades of sharp or cutting tools, in particular knife blades.

Sharp cutting blades require regular maintenance to maintain cutting power.

This maintenance consists of regular grinding operations during which the cutting is reformed by means of a wheel or a suitable machine; between two sharpening operations, the wear of the cutting edge is delayed by sharpening operations by means of a tool called a "rifle", by means of a diabolo sharpener, or by means of a module of sharpening with crossed pins (fixed or articulated).

The type of sharpening rifle used is a function of the degree of wear of the blade. Often the operator uses a "rough" shotgun to rough out the work, before using a "smooth" finishing gun to burn the blade wire.

But the implementation of these sharpening rifles requires significant technical expertise and an experienced hand; as a result they can not be used effectively by anyone.

The diabolo-type or fixed-pinch-type edgers are inefficient and do not provide an interesting sharpening quality.

The sharpening machines of the articulated cross-pin type are generally used to brown the tool blades and have the advantage of being able to be used satisfactorily even by people who do not have a great deal of experience or a high degree of technicality. in the field of sharpening.

An apparatus of this type, described in US-A-5 478 272, consists of a planar base in which is arranged a vertical slot for the passage of the blade to sharpen, and provided with two sharpening pins which intersect opposite the said slot. The two sharpening spindles, made of steel wire, have a generally curved shape and they are articulated at their upper end on the flat base, by means of rotary knobs associated with return springs. These pins form between them a vee sharpening which is movable under the pressure of the tool blade that is desired to sharpen; the corresponding Vee mobile ensures a regular or relatively regular treatment pressure on the tool blade.

Lower and upper stops limit the pivoting of said pins between a high position and a low position.

Another apparatus of the articulated cross-pin type, operating according to the same principle, is described in document EP-1 260 318.

Here, the sharpening pins are carried by a metal plate whose lower end is extended by a flat monobloc tab located in the plane of said plate, and whose width decreases from top to bottom. This tab is used to grip the device, with one hand, by an operator who wishes to treat the blade of a tool held by the other hand; it can also be used to fix the device on a suitable support. The plate of this device (with its monobloc tab) is made from a metal sheet cut and folded.

But the holding of the device by its gripping lug, when working on the tool, is a source of risk of cut-off injury to the hand of the operator. In addition this tab does not allow an optimal grip of the device.

A similar device, made of molded plastic material, is described in document DE-10 2007 005 974. Here again, the one-piece gripping lug extends in the same plane as the tool-holder plate; a projecting flap extends forwardly between the tool plate and the gripping tab, to act as a safety abutment member.

This type of molded plastic device is not very easy to maintain and clean. In addition, the tools being processed can cut small parts, at risk in the food industry, to find some in food.

The present invention provides an improvement to this type of sharpening apparatus, to overcome the aforementioned drawbacks, easy to manufacture and clean, and also providing great safety of use, as well as a good handling.

For this, in the sharpening apparatus according to the present invention, the lower end of the pin support plate is extended, on the side of its rear face, by an intermediate flap, which itself is extended by said leg gripper, the latter extending in a plane P 'which is parallel or substantially parallel to said plane P of said plate, and which is offset with respect to this plane P, on the side of said rear face of said plate. The intermediate flap is delimited by - a front edge connected to the lower end of said platen, - a rear border, parallel to the front edge, connected to the upper end of the gripping tab, and - two lateral edges, said front and rear borders defining the width I of said intermediate flap;

and to optimize the maintenance and safety of the hand of the operator, the lateral edges of the intermediate flap are each extended by a side ear.

In addition, the plate, the intermediate flap, the gripping tab and the lateral lugs of the apparatus are made in one piece of sheet metal cut and folded (advantageously a stainless steel sheet whose thickness is between 2 and 4 mm). .

The intermediate flap is a kind of stop for the edge of the hand that carries the device (especially for the top of the thumb or forefinger), thus facilitating the holding of the device by the same hand, and substantially limiting the risk of reaching this hand by the blade of the tool being processed.

The combination of the intermediate flap and side lugs allows a very good ergonomics of the device when held by hand. Indeed, the distribution of the weight is improved by providing additional support, especially on the top of the thumb or forefinger, and reducing the effort required to grip the handle. According to a preferred embodiment, the intermediate flap is in the form of a plane flap which extends at right angle or substantially at right angles to plane P of the plate, and the gripping tab extends to square or substantially square to said intermediate flap.

To ensure good support and optimum safety, the width I of the intermediate flap is preferably between 20 and 40 mm.

Preferably, the lateral lugs are flat and they extend over all or substantially the entire width I of the intermediate flap, in a plane inclined by a few degrees, relative to the plane of this intermediate flap, in the direction of the gripping lug.

The corresponding angle of inclination of each lateral ear relative to the plane of the intermediate flap is advantageously between 10 and 40 °, preferably between 20 and 30 °.

The invention will be further illustrated, without being limited in any way, by the following description of a particular embodiment, given solely by way of example and shown in the accompanying drawings in which:

- Figure 1 is a perspective view of a sharpening apparatus according to the present invention;

Figure 2 is a side view of the apparatus illustrated in Figure 1;

FIG. 3 is a front view of the apparatus illustrated in FIGS. 1 and 2;

- Figure 4 is a top view of the apparatus shown in Figures 1 to 3.

The sharpening apparatus shown in FIGS. 1 to 4 consists of a metal plate 1 in the central zone of which is arranged an opening 2 which opens upwards.

In the upper part of this opening 2, the plate 1 comprises monobloc extensions 3 and 4 constituting supports, on the one hand for a pair of flat blades 6, 7 intended to guide the blade of the tool that is desired sharpening, and secondly for two sharpening pins 8, 9 which intersect just in front of said guide blades 6, 7.

Platinum 1 has a generally triangular shape; it is flat and extends in a plane P. This plate 1 is delimited by a front face 10, a rear face 1 1, an upper end 12, a lower end 13 and two lateral sides 14,15.

The opening 2 has a generally triangular shape that opens upwards and opens into the upper end 12.

The lower end 13 of the plate 1 extends rearwardly (that is to say on the side of its rear face 1 1), square or substantially square, by a one-piece intermediate flap

16 which extends itself, at the square or substantially square, by a monobloc leg

17 useful for gripping the device, and possibly for its attachment to a suitable support.

The intermediate flap 16 is flat and has a generally rectangular or substantially rectangular shape. This flap 16 has a front edge 18 and a rear edge 19, parallel to each other, and two side edges 20, also parallel to each other. The distance separating its borders before 18 and rear 19 corresponds to its width I. This flap 16 extends in a plane perpendicular or substantially perpendicular to the plane P of the plate 1; it is connected to the lower end 13 of said plate 1 at its front edge 18.

The one-piece lug 17 has a generally triangular shape with a decreasing width from top to bottom; it is flat and its upper end 21 is connected with the rear edge 19 of the intermediate flap 16.

This gripping tab 17 extends in a plane P 'which is parallel to the plane P of the plate 1. This plane P 'is shifted rearward with respect to the plane P of the plate 1 (that is to say on the side of the rear face 1 1 of the plate 1), that of a distance I corresponding to the width of the intermediate flap 16.

On the other hand, it is noted that the lateral edges 20 of the intermediate flap 16 are extended by one-piece lugs 22 whose width corresponds substantially to that of said intermediate flap 16.

As can be seen in particular in FIGS. 1 to 3, these lugs 22 extend in a plane which is slightly angularly offset downwards (that is to say in the direction of the gripping tab 17), by report to the middle tier plan 16.

The angle of inclination corresponding to is preferably between 10 and 40 ° and more preferably between 20 and 30 °; it is here of the order of 25 °.

It will be understood that when an operator holds the sharpening apparatus in his hand by the tab 17, the intermediate flap 16 serves as a protective guard for this hand. The support of the index finger and / or the thumb against the lower surface of this flap 16 further optimizes the maintenance of the apparatus The two lateral lugs 22 increase the protection obtained, as well as the comfort of maintenance by a greater distribution contact surfaces. Their slight inclination downwards relative to the plane of the flap 16 optimizes the ergonomics of handling.

On their side, each support 3, 4 is in the general form of L made in one piece with the plate 1.

In particular each support 3, 4 is formed from the upper end of the opening 2, along one of the borders of this opening 2, and extends cantilevered forward.

The two supports 3 and 4 comprise a base 23 which extends perpendicularly to the plane P of the plate 1, extended by an end flange 24 which extends perpendicular to said base 23 and parallel to the plane P of the plate 1 ( in a plane shifted forward with respect to the plane P of the plate 1).

The base 23 of the supports 3 and 4 comprises a threaded orifice which allows the removable attachment of the flat blades 6 and 7 by means of a screw 25. This threaded orifice can be obtained by means of a threaded insert crimped on a hollow orifice in the base 23.

The two flat blades 6 and 7 are made for example of stainless steel; they are arranged vis-a-vis and they extend perpendicular to the plane of the plate 1. These blades 6, 7 each comprise an L-end return 26 which allows their attachment to the supports 3 and 4 by means of the screws 25; from this return in L 26, the two blades 6 and 7 take each the shape of a dihedron together to form a first flared Vee 27 in the upper part of the opening 2, followed by a second constricted Vé 28, in the lower part of said opening 2 (Figure 3).

The lower edges 29 and 30 of the two blades 6 and 7 come into contact with each other to form a self-tightening guide system.

As described in EP-1 260 318, just above their lower edge 29 and 30, the two blades 6 and 7 have offset internal cutouts 31 and 32 which form one-piece folded tongues in the opposite direction. the other to form a VE 33 for straightening the wire of the tool blade, in perfect alignment.

The angle formed between them these two tabs 31, 32 is of the order of 40 °.

Each of these one-piece tabs is associated with a lateral opening for embedding the homologous tongue.

As described in EP-1 260 318, the two sharpening pins 8 and 9 are made of wire, for example stainless steel wire. They consist of a U-shaped rod, comprising two parallel arms secured to one of their ends and whose free ends comprise monobloc returns to the bracket which come to slip into suitable holes arranged in the wing end 24 of the supports 3 and 4.

This embedding of the pin returns in the associated orifices allows the articulation of the pins 8 and 9 on their respective support 3, 4, about axes perpendicular to the support plate 1.

These orifices extend perpendicularly to the plane of the plate 1 and they pass right through the end flange 24 of the supports 3 and 4.

At this level we note the presence of parts 24 'reported by welding on the outer faces of the wings 24 to increase their thickness. These inserts 24 ', in which are formed the recessing holes of the pins, serve to maintain a well-defined separation of the two arms of the pins, because, here, the small thickness of the sheet used to form the plate 1 and its monobloc supports 3 and 4.

These parts 24 'prevent the pins from rubbing against one another and they provide a pivoting of these pins without parasitic friction.

On the other hand, the orifices formed in these inserts 24 'and which extend in the flange 24 of the supports 3 and 4, ensure good guidance of the pin returns and ensure a rotation perfectly perpendicular to the plane of the support plate 1 .

The two corresponding orifices are off-center on each wing 24 to obtain an elastic return system of the pins 8 and 9 by a twisting effect of the two parallel arms, as detailed in the document EP-1 260 318. The positioning of the pin returns, and that of the two reception ports, is adapted to obtain the desired elastic return characteristics. At rest, the two arms of the pins 8 and 9 are parallel, and one of these arms has a slightly longer length than the other to offset the two end returns, to allow their embedding in the associated holes .

These returns are oriented in the opposite direction to each other so that the two parallel arms of the pins 8, 9 are positioned on either side of the end wings 24 of the supports 3 and 4, this positioning being possible thanks to to the elasticity of the end link of said pins. The corresponding returns are simply fitted into the receiving holes, free from rotation and removable.

The two sharpening spindles 8 and 9 are mounted nested one inside the other to optimize the sharpening operations, and also to limit the size of the device.

In Figures 1 and 3, note the general curved shape of the two pins 8 and 9, which allows to keep between them an angle of the order of 40 °, regardless of the depth of penetration of the tool blade.

At rest, the two sharpening pins 8 and 9 are in the high position, their end being blocked by abutment structures 34 arranged on the sides of the plate 1. These stops 34 can be made in one piece by folding the lateral parts of the plate 1; they may also consist of independent elements, reported and fixed by any appropriate means.

At rest, it is noted that the two sharpening spindles 8 and 9 intersect just below the level of transition between the flared V 27 and the constricted V 28 of the guide blades 6 and 7.

In the embodiment described above, the plate 1, the intermediate flap 16, the lugs 22, the lug 17, the supports 3 and 4, as well as the stops 34 are made in one piece from a cut sheet metal and folded, preferably a stainless steel sheet whose thickness is between 2 and 4 mm.

In an alternative embodiment this assembly could be obtained from molded plastic.

In general, the height of this device may be of the order of 280 mm, its width of the order of 130 mm, and its thickness of about 80 mm. The width I of the intermediate flap is advantageously between 20 and 40 mm.

The sharpening apparatus can be used held by hand or installed in or on a suitable stand attached to the workstation. The apparatus can thus very easily be removed from its support, in particular for cleaning or disinfection.

An inner cut 35 arranged in the one-piece lug 17 makes it possible to lighten the weight of the apparatus.

Once the device is held in the hand or positioned vertically on its support, the operator places the tool blade that he wants to sharpen between the two blades 6, 7 which form a self-tightening guide. If he wishes to use the straightening vee 33 formed by the two one-piece tongues 31 and 32, he exerts a vertical pressure on the tool, sufficient for his blade to reach said Vee 33; the operator can then perform the back and forth movements adapted to "work" the wire of the tool blade, in a manner similar or related to conventional work by a "rough" shotgun.

The tool blade is then guided by the self-clamping vee guide blades 6, 7 which ensures a perfect working angle.

The two sharpening pins 8 and 9 are then used to finish the sharpening operation, ie to "brown" or smooth the tool blade, as can be done classic by means of a "smooth" shotgun.

The operator then moves back and forth of the tool blade on the two sharpening spindles 8, 9, exerting a pressure just enough not to reach the straightening Vee.

The two sharpening pins 8 and 9 are similar to mobile torsion bars in the form of arches and they allow to keep between them, and regardless of the depth of penetration of the tool blade in the constricted Vé 28 , the right angle of attack to optimize the work on the wire of the blade.

The downward movement of the tool blade is limited by the presence of the straightening vee 33 and it is therefore not necessary to provide low abutment structures for the two sharpening pins 8 and 9. In any state Because of this, the two pins 8 and 9, nested one inside the other, can not deviate from each other in the lower part.

The two sharpening pins 8 and 9 intrinsically have their own elastic return means, which simplifies the structure of the device. In addition, these two pins can easily be dismantled and reassembled from their support, especially for maintenance operations.

The apparatus according to the present invention has a relatively simple overall structure and is very complete since it proposes two associated assemblies that make it possible to work the wire of the tool blades differently.

On the other hand, the presence of the intermediate flap 16 and one-piece lugs 22 optimize its safety of use and its handling in hand.

Claims

- CLAIMS - 1 .- Apparatus for sharpening the blades of cutting tools, comprising a plate (1) extending in a plane (P), which plate (1), delimited by a front face (10), a rear face (1 1), an upper end (12), a lower end (13) and two lateral sides (14, 15), is provided with an opening (2) opening into said upper end (12), for the passage of the tool blade, opposite which opening (2) are arranged two elongate pin-shaped sharpening structures (8, 9), each articulated at one of their ends on said plate (1), each of one side of said opening (2), and which pins (8, 9) comprise elastic return means, so as to obtain a Vé of mobile sharpening under the pressure of the blade to be sharpened, which plate (1 ) further comprises a gripping tab (17) extending from said lower end (13),

characterized in that said lower end (13) of said plate (1) extends, on the side of its rear face (1 1), by an intermediate flap (16), which itself is extended by said gripping tab ( 17), the latter extending in a plane (Ρ ') which is parallel or substantially parallel to said plane (P) of said plate (1), and which is offset with respect to said plane (P), on the side of said face rear (1 1) of said plate (1), said intermediate flap (16) being delimited by - a front edge (18) connected to the lower end (13) of said plate (1), - a rear edge (19) ), parallel to said front edge (18), connected to the upper end (21) of said gripping tab (17), and - two side edges (20), said front (18) and rear edges (19) defining the width (I) of said intermediate flap (16), and said lateral edges (20) of said intermediate flap (16) being cune extended by a side lug (22), said plate (1), said intermediate flap (16), said gripping lug (17)

and said lateral lugs (22), being made in one piece of sheet metal cut and folded.

2 - Apparatus according to claim 1, characterized in that said intermediate flap (16) is in the form of a plane flap which extends to the square or substantially square to the plane (P) of said platen (1). ), and in that said gripping tab (17) extends to the square or substantially square to said intermediate flap (16).

3 - Apparatus according to any one of claims 1 or 2, characterized in that the width (I) of the intermediate flap (16) is between 20 and 40 mm.

4 - Apparatus according to any one of claims 1 to 3, characterized in that each of said side lugs (22) is flat and extends over all or substantially the entire width (I) of said intermediate flap (16), in a inclined plane of a few degrees, relative to the plane of said intermediate flap (16), in the direction of the gripping lug (17).

5 - Apparatus according to claim 4, characterized in that the angle of inclination (a) of each side lug (22) relative to the plane of the intermediate flap (16) is between 10 and 40 °.

6 - Apparatus according to any one of claims 1 to 5, characterized in that it comprises a plate (1), an intermediate flap (16), a gripping lug (17) ears side members (22), made of cut and folded stainless steel sheet whose thickness is between 2 and 4 mm.