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Publication numberUS3808746 A
Publication typeGrant
Publication dateMay 7, 1974
Filing dateSep 14, 1971
Priority dateAug 13, 1971
Also published asDE2140596A1
Publication numberUS 3808746 A, US 3808746A, US-A-3808746, US3808746 A, US3808746A
InventorsKnecht F
Original AssigneeTecmed Ag
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Apparatus for grinding of knives in particular of a hand-knife and cutter-knife
US 3808746 A
Abstract
An apparatus for grinding of knives, particularly of hand-knives and cutter-knives, which comprises rotatable grinding discs having side faces adapted to have the cutting edge of knives press against the side faces. A non-rotatable protection housing includes a central drive member, and the grinding discs are disposed opposite each other from said central drive member. The protection housing has insertion slots for a knife blade, which slots form cuts of the protection housing. The cuts are disposed in a plane extending obliquely to the axis of the grinding discs, the oblique position determining the grinding angle.
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United States Patent 1191 Knecht May 7,1974

[ APPARATUS FOR GRINDING OF KNIVES IN PARTICULAR OF A HAND-KNIFE AND CUTTER-KNIFE [75] Inventor: Fritz Knecht, Vogt/l-leissen, Germany [73] Assignee: Tecmed A.G., St. Margrethen, Switzerland [22] Filed: Sept. 14, 1971 [211 Appl. No.: 180,306

[30] Foreign Application Priority Data [58] Field of Search 51/128, 102, 218 R, 218 11, 51/218 T, 125.5, 124

2,722,783 11/1955 ORussa 51/128 UX 2,860,452 11/1958 2,865,141 12/1958 3,332,173 7/1967 McMaster et a1 51/128 FOREIGN PATENTS OR APPLICATIONS 530,625 12/1940 Great Britain 51/102 625,431 8/1961 Canada 51/128 Primary Examiner-Al Lawrence Smith Assistant Examiner-Nicholas P. Godici [57] ABSTRACT An apparatus for grinding of knives, particularly of hand-knives and cutter-knives, which comprises rotatable grinding discs having side faces adapted to have the cutting edge of knives press against the side faces. A non-rotatable protection housing includes a central drive member, and the grinding discs are disposed opposite each other from said central drive member. The protection housing has insertion slots for a knife blade, which slots form cuts of the protection housing,

[56] References Cited I UNITED STATES PATENTS The cuts are disposed n a plane extend ng obhq u ely 90] 059 10/1908 B H W to the axis of the grmdlng discs, the oblique position a 1,200,605 10/1916 Gleckler 51/218 A x determnimg the grmdmg angle 2,16l,992 6/1939 Battocchi 51/102 4 Claims, 6 Drawing Figures [5 II I] I2 I! If 20 l8 l6 I APPARATUS FOR GRINDING OF KNIVES IN PARTICULAR OF A HAND-KNIFE AND CUTTER-KNIFE The present invention relates to an apparatus for grinding of knives, in particular of hand and cutter knives, wherein the cutting edge is pressed onto the side faces of rotating grinding discs.

For grinding of knives, which are used in businesses, for example, in butcheries in addition to a good cutting effect, there is desired the longest possible service life of the cutting edge. Furthermore the grinding should be performed as quickly as possible, as well as perfectly, also by lesser skilled labor.

These requirements can be complied with insufficiently only with devices of conventional nature, since they provide a bad grinding image by a faulty guidance in case of manual operation. Machines have been proposed already, in which the knife is rigidly clamped in a predetermined position relative to the disc. This has the drawback, that the handling is complicated, as much as it is supposed to fulfill all factors of the grinding quality.

It is one object of the present invention, to provide an apparatus for grinding of knives, wherein the abovementioned drawbacks are avoided and furthermore still additional advantages are achieved.

It is another object of the present invention, to providean apparatus for grinding of knives, wherein the grinding discs are disposed in a non-rotating, preferably cylindrical protection housing, which has insert slots for the knife blade, at the right and at the left from a central drive, whereby these slots form housing cuts, which are arranged in a plane extending obliquely to the axis of the grinding disc, the oblique position of the plane determining the grinding angle. Advantageously the protection housings for the grinding discs are thereby equipped with a layer of synthetic material, which serves the enlargement of the oblique engagement face at the housing cut and the improvement of the knife support.

By this arrangement it is possible, to move the knife relative to the grinding disc in an exact guide maintaining the grinding angle at first on the one blade side and then on the other blade side, whereby by the oblique position of the guide the radial pressing-in results in the engagement pressure. By this arrangement a parallel cutting chamfer with wedge-shaped cross-section is created, which in its finest range, as set forth below, can be secured by lapping, by a lapping disc having a different degree of fineness from that of a grinding disc.

The apparatus of the present invention is characterized first of all by a low structural expenditure'and simple handling. By the arrangement of the grinding disc on both sides of the drive, the cutting chamfer can be ground on both of its sides, without necessity that the grinding operator changes his position. The danger of an accident is completely removed, since the grinding discs are covered outwardly, continuously and on all sides.

In a further development of the present invention, a holding-and guiding-device for the knifeto be ground is provided, which device is secured by example on the cover sleeve and which controls automatically the suitable knife movements during operation. By this arrangement it is to be achieved first of all, that nonskilled labor can perform the grinding process quickly and exactly.

With these and other objects in view, which will become apparent in the following detailed description, the present invention, which is shown by example only, will be clearly understood in connection with the accompanying drawings, in which:

FIG. I is a top plan view of the apparatus designed in accordance with the present invention;

FIG. 2 is an elevation of the apparatus shown in FIG. 1;

FIG. 3 is a top plan view of the arrangement scheme of the grinding-and holding-discs;

FIG. 4 is an elevation of the holding-and guidedevice;

FIG. 5 is a top plan view of the device shown in FIG. 4; and

FIG. 6 is an end view of the device shown in FIG. 5

seen in the direction of the arrow P. Referring now to the drawings, and in particular to FIGS. 1 to 3, the apparatus comprises a motor housing 1, wherein a motor having a cross drive which may include a reduction gear, the drive including oppositely disposed shafts 2 and 3, is arranged. The grinding discs 6 and 7, respectively, sit on holding discs 4 and 5,,respectively, and lapping discs 9 and 10, respectively, on holding discs 8, which discs are secured to the shafts 2 and 3. As can be determined from FIG. 3, this arrangement is preferred.

The discs 4 to 10 are provided in protection housings 11 and 12, which are laterally mounted on the motor housing 1. These protection housings II and 12 are equipped with oblique insert slots 13 and 14, which result, by example, in a lapping angle of 18. Furthermore a cover sleeve .15 slides over each of the protection housings 11 and 12, which cover sleeve 15 has a recess 16 and 17, respectively, for the slot 13 and 14, respectively, and which has in addition a longitudinal slot A, so that it is axially displaceable and rotatable. This movability can be blocked and braked, respectively, by a clamping screw 18.

At its outer end each of the cover sleeves 15 is equipped with a cover 19 of synthetic material extending towards the inside. This cover 19 has two insert slots 20 and 21, which slots are diametrically arranged relative to each other on its periphery. These slots 20 and 21 have different oblique angles, by example, the slot 20 an angle of 15 and the slot 21 an angle of only 5.

These arrangements make it possible, to perform grindings with a different grinding angle on each side. For thispurpose, the knife is inserted into the slot 20 and moved slightly back and forth. In order to grind the other cutting edge chamfer, the knife is inserted into the slot 20 at the right of the motor housing 1, and one proceeds in the same manner. The lapping takes place by insertion of the knife into the slot 13 or 14, respectively.

In order to obtain the advantageous formation of the cutting edge with a hollow grindingand a short parallel piece before the cutting edge, the grinding line can be provided inclined at 5 to the radial plane of the grinding stone. If the grinding line is eccentrically displaced upwardly or downwardly, a curvature results forcibly in the grinding range (conical section), whereby a concave cutting edge is obtained, the service life of which is many times longer, than with a plane cutting edge.

The cooling takes place in a simple manner such, that a container 22 is provided for the cooling medium, in which the rotating discs are suspended. Thereby the liquid is taken upwardly and cools the disc. A displacement of the axis of the shafts relative to the axis of the protection housing increases this effect. The arrangement of spiral-shaped grooves on the inner face of the cover 19 of synthetic material can serve the same purpose. Furthermore it is suitable, to equip the supporting edges of the slots 13 and 14 with a layer 13a and 14a, respectively of synthetic material, so that the cutting edge of the knife is not subjected to metal engagement.

Referring now again to the drawings, and in particular to FIGS. 4 to 6, the holdingand guiding-device is disclosed.

A holding member 26 is secured on the cover sleeve 15, which can be clamped, by example, by a clamping device 18, 25, in which holding member 26 is mounted a swinging axle 27. A guide arm 28 is provided on the outer end of the swinging axle 27 by means of a settable connecting member 24. The guide arm 28 extends parallel to the oblique insert plane of the guide slot upwardly and is equipped in the range of its upper arm with a connecting arm 29, which is secured adjustable to its height on the guide arm 28 by means of a clamping connection 30. The connecting arm 29 has a handle 31 at its outer end for the left hand.

A holder 32 which is adjustable to its length and fixable sits on the connecting arm 29 for a receiving head 33, which is equipped with a rotary axle 34 and a receiving plate 36 for a cutter knife 37 is forcibly connected with a hub 35 of the rotary axle 34, by example, by means of a connecting bolt.

The cutter knife 37 is retained by a clamp clip 38,

which is secured to the receiving plate 36 by a screw. In order to secure thereby the correct position of the cutter knife 37, the knife-sided face of the receiving plate 36 is equipped with a form plate 39 having the thickness of the knife 37, the configuration shape of which form plate 39 corresponds with the profile of a receiving recess 40 of the cutter knife 37.

A grip 41 is provided on the hub 35, which is operated with the right hand of the operator and by which the hub 35 with the receiving plate 36 can swing about the axle 34. The grinding disc-6 with its holding disc 4, as well as the shaft 2 and the motor housing 1, which elements are members in the grinding apparatus are indicated partly in dotted lines.

In the operation of the described device, at first the unit consisting of the parts 28 to 41, which is swingable about the swinging axle 27, is turned upwardly in the direction of the arrow A (FIG. 6) by use of the grip 31 so far, that the cutter knife 37 to be ground can be secured to the receiving plate 36. By selection of the receiving plate 36 with the complementary form plate 39 it is brought about, that the axis of the rotary axle 34 of the receiving head 33 forms the center point of the knife-chamfer with the radius R, whereby setting possibilities are provided by the adjustable and fixable connecting members, by examples by the members 24, 30 and 32.

By swinging of the unit in the direction of the arrow E (FIG. 6), the cutter knife 37 is inserted into the slot 20 of the cover tube 15, up to the engagement with the grinding disc 6. This state is clearly indicated in FIGS. 4, 5, and 6. During the grinding process, the receiving plate 36 can be moved back and forth together with the knife 37 for performance of the grinding process by means of the grip 41. It is then possible by use of the grip 31 to vary the engagement pressure as required, whereby by a simple lifting of the unit in the direction of the arrow A, the grinding state can be examined at any time.

Since the cutter knife has normally a cutting chamfer on one side only, the arrangement of the holding device designed in accordance with the present invention suffices on one side only of the grinding apparatus. It is also possible, however, to lift in a simple manner the device from the holder 26, if required, and to secure the same on the grinding apparatus on the other side of the motor housing 1 in a corresponding holder.

As stated above, the holdingand guiding-device is characterized by extensive setting possibilities, so that cutter knives 'of all existing sizes can be ground by simple exchange of the receiving plate 36 and setting the radius R. In order to adjust thereby the position of the gripping lever 41, the hub 35 is formed settably relative to the device joining the receiving plate, by example, a bolt, by rotation and reversing of the bolt.

While I have disclosed one embodiment of the present invention it is to be understood that this embodiment is given by example only and not in a limiting sense.

I claim:

1. An apparatus for grinding of knives, particularly of hand-knives and cutter-knives, comprising at least four rotatable grinding and lapping discs having different degrees of fineness having lateral sides faces for the cutting edge of knives to press against said side faces,

a non-rotatable protection housing including a central drive member,

said grinding and lapping discs being disposed opposite each other from said central drive member, with two of said discs on each side of the latter,

said protection housing having insertion slots for a knife blade, said slots forming cuts of said protection housing,

said cuts being disposed in a plane extending obliquely to the plane of said discs, the obliqueposition determining the grinding angle, such that grinding of said knife blade when inserted into said cuts being against said lateral side faces of said discs,

a cover sleeve which is axially displaceable and rotatable above said protection housing,

said cover sleeve having longitudinal slot and being clamped by a screw, as well as defining a recess for the insertion slot for a knife blade.

2. The apparatus, as set forth in claim 1, wherein said cover sleeve has at its cover periphery two insertion slots having different grinding angles, so that upon rotation for the grinding angle can be varied. 3. The apparatus, as set forth in claim 1, which includes a plurality of said grinding discs disposed adjacent each other on a common axis and outwardly covered by said protection housing and said cover sleeves, and at least one of said lapping discs mounted on said common axis.

4. An apparatus for grinding of knives, particularly of hand-knives and cutter-knives, comprising at least four rotatable grinding and lapping discs having different degrees of fineness having lateral sides faces for the cutting edge of knives to press against said side faces,

a non-rotatable protection housing including a central drive member,

said grinding and lapping discs being disposed opposite each other from said central drive member, with two of said discs on each side of the latter,

said protection housing having insertion slots for a knife blade, since slots forming cuts of said protection housing,

said cuts being disposed in a plane extending obliquely to the plane of said discs, the oblique pocircular and closed on top.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US901059 *Apr 25, 1907Oct 13, 1908Kelly Axe Mfg CoScythe-grinder.
US1200605 *Jul 12, 1916Oct 10, 1916Christoph GlecklerBlade-sharpening device.
US2161992 *Feb 1, 1937Jun 13, 1939Silvio BattocchiRotary knife sharpener
US2722783 *Mar 27, 1953Nov 8, 1955Lorence O'russaKnife sharpener
US2860452 *Aug 19, 1957Nov 18, 1958Lebus William AKnife sharpener
US2865141 *Aug 22, 1957Dec 23, 1958Oster Mfg Co JohnMotor driven sharpener for edged tools
US3332173 *Jun 30, 1964Jul 25, 1967Cory CorpSharpener for cutting instruments
CA625431A *Aug 8, 1961Sunbeam CorpAbrading machine
GB530625A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3909985 *Dec 6, 1972Oct 7, 1975Tecmed A GApparatus for grinding a knife including knife holding and guiding means
US4050197 *Aug 14, 1975Sep 27, 1977Thompson Willis FBlade and scissors sharpener
US4182615 *Jan 5, 1978Jan 8, 1980Ipco Hospital Supply CorporationDental model trimmer
US6802763Oct 25, 2002Oct 12, 2004Salton, Inc.Apparatus for sharpening blades
EP2324953A3 *Nov 11, 2010Jun 3, 2015Newrox AGGrinding machine
Classifications
U.S. Classification451/282
International ClassificationB24B3/00, B24B3/54
Cooperative ClassificationB24B3/54
European ClassificationB24B3/54