US3587953A

US3587953A - Method and apparatus for severing of metal band or metal plate

Info

Publication number: US3587953A
Application number: US791822*A
Authority: US
Inventors: Max Stehle; Egon Kirchner
Original assignee: BBC Brown Boveri France SA
Current assignee: BBC Brown Boveri AG Germany; BBC Brown Boveri France SA
Priority date: 1967-08-24
Filing date: 1968-08-26
Publication date: 1971-06-28
Anticipated expiration: 1988-06-28
Also published as: BE719873A; AT280015B; FR1579189A; GB1238377A

Abstract

METHOD OF SEVERING METAL SHEET SUCH AS BANDS AND PLATES INTO STRIPS INCLUDES FEEDING THE SHEET IN A GIVEN DIRECTION, PASSING A CHIP-REMOVING TOOL TRANSVERSELY TO THE FEED DIRECTION OVER THE SHEET AT A RIGIDLY SUPPORTED LOCATION THEREOF SO AS TO FORM A GROOVE IN THE SHEET HAVING A DEPTH EQUAL TO AT LEAST HALF THE THICKNESS OF THE SHEET, AND OSCILLATING THE SHEET PORTIONS ON BOTH SIDES OF THE GROOVE RELATIVE TO ONE ANOTHER SO THAT THE REMAINDER OF THE THICKNESS OF THE SHEET IS BROKEN THROUGH ALONG THE GROOVE, AND DEVICE FOR CARRYING OUT THE FOREGOING METHOD.

Description

Inventors Appl. No. Filed Patented Assignee Priority Max Stehle Mannheim;

Egon Kirchner, Manuheim-Feudenheim, Germany Aug. 26, 1968 June 28, 1971 Brown, Boveri & Cie Aktiengesellschaft Mannheim-Kafertal, Germany Aug. 24, 1967 Germany METHOD AND APPARATUS FOR SEVERING OF METAL BAND 0R METAL PLATE [56] References Cited UNITED STATES PATENTS 662,924 12/1900 Dugon 225/96.5 2,053,375 9/1936 Nicholas 29/413UX 2,242,967 5/1941 Carlile 29/413UX 2,471,650 5/1949 Pandolfi 29/413X 3,138,308 6/1964 Oakley 225/2 3,233,443 2/1966 Lawson 225/96.5X

Primary Examiner-Frank T. Yost Attorneys-Arthur E. Wilfond, Herbert L. Lerner and Daniel J. Tick ABSTRACT: Method of severing metal sheet such as bands and plates into strips includes feeding the sheet in a given direction, passing a chip-removing tool transversely to the feed direction over the sheet at a rigidly supported location thereof so as to form a groove in the sheet having a depth equal to at least half the thickness of the sheet, and oscillating the sheet portions on both sides of the groove relative to one another so that the remainder of the thickness of the sheet is broken through along the groove; and device for carrying out the foregoing method.

PATENTED JUN28 1971 m Q Q Jnrenfors lla oL Qfe 02.,

METHOD AND APPARATUS FOR SEVERING F METAL BAND 0R METAL PLATE Our invention relates to method and device for severing metal sheet such as metal bands or metal plates in a direction transverse to the direction of feed of the metal sheet so as to form strips thereof.

Strip-shaped metal sheets, which can be used for example in apparatus and appliance construction, are generally not rolled directly from an ingot or the like for reasons of economy, but rather must be produced by severing a metal band which has been rolled into a relatively large area or by severing metal plates which had been previously cut from metal bands.

In accordance with a heretofore known method, the strips are cut along the severing line of a metal band or a metal plate by means of a blade located above and below the metal band or plate [Dubbels Taschenbuch fiir Maschinenbau (Dubbels Handbook of Engineering) 1963, 12th Edition, Volume II, page 733]. The strips which were severed by this known process are subjected to warping, however, and have a saberlike defonnation. These phenomena occur particularly when severing narrow strips of thin sheet metal, so that the strips must be straightened out once again in a special device. Furthermore, the strips are produced with faulty measurements which makes subsequent confonning or strotyping and processing necessary. In addition, the strips are formed with burrs on the surfaces thereof which must frequently be removed in a special device.

It is also known to straighten out the edges of rolled metal bands or metal plates by employing chip-forming cutting tools (Gennan Pat. No. 1,022,079). However, chip-forming tools have'never been mentioned in connection with the severing of narrow strips of thin metal bands or metal plates.

It is an object of our invention to provide method and device for severing metal sheets such as metal bands or metal plates of relatively small thickness into desirably narrow strips without warping the strips or giving them a saberlike defonnation, as well as without leaving any burrs thereon.

With the foregoing and other objects in view, we provide method of severing metal sheets such as metal bands and metal plates into strips, in accordance with our invention, which comprises feeding the metal sheet in a given direction, passing a chip-removing tool transversely to the feed direction over the metal sheet at a rigidly supported location thereof so as to form a groove in the metal sheet having a depth equal to at least half the thickness of the metal sheet, and oscillating the metal sheet portions on both sides of the groove relative to one another so that the remainder of the thickness of the metal sheet along the groove is broken through.

In accordance with further features of our invention, we provide device for carrying out the aforementioned method comprising a plurality of chip-removing tools adapted to successively pass over the metal sheet along a severing line with successively increasing cutting depth so as to form the groove in the metal sheet. Thelife of the tool cutting edge is thereby increased in an advantageous manner.

In accordance with further features of our invention, the chip-removing tools comprise, in particular, pins with points consisting of hard and pyramidal ground material as well as planing or turning tools, and furthermore end-milling cutters and grinding pins rotating about the longitudinal axes thereof or grinding discs, circular saws and milling tools rotating in the same or opposite direction to the feeding movement thereof.

In order to be able to break through the material of the metal sheet remaining beneath the groove formed in the metal sheet with the least possible relative oscillating movements of the metal sheet on both sides of the groove, the groove should be formed relatively deeply. However, the groove should not be so deep that the material of the metal band or metal plate on the side lying opposite to that in which the groove is formed is pressed out of the smooth surface of the metal band or metal plate due to the pressure of the chip-removing tool and thereby is capable of damaging the surface of the support carrying the metal band or plate. In view of this requirement, the maximum depth of the groove, dependent upon the respective hardness of the metal band or the metal plate material, is slightly more than percent of the thickness of the metal band or metal plate.

When fully severing a band or plate in one operation by means of one or more chip-removing tools, the danger arises that the band or plate will be lifted too easily from the support on which the band or plate lies in the region wherein the severing occurs, and will then be ripped or split open in an uncontrollable manner and deformed, resulting in possible damage to the tool. A further disadvantage of severing the metal band or plate in a single operation is the possible formation of an undesired burr on the surface of the strips formed by the severing operation. In accordance with the invention of the instant application, the formation of burrs is avoided especially when the portions of the band or plate on both sides of the groove formed in the plate are first bent upwardly so that .the groove is enclosed therebetween, as opposed to being bent downwardly so that the groove is at the vertex of the angle formed by the portions of the band or plate, in other words, the portions of the band or plate-are first bent inwardly into the groove.

In accordance with further features of our invention, after the groove has been formed in the band or plate, the chipremoving tool is made to retrace its path either after being raised slightly or turned slightly, or even if it is permitted to maintain the same relative level thereof as that at which it cut the groove in the band or plate. Thereafter, by relative movement of the portions of the band or plate on opposite sides of the groove, strips of the metal are broken from the band or plate along the groove. Obviously, the strips can be broken from the thus scored or grooved metal band or plate even before the chip-removing tool retraces its path. Thereafter, the metal band or plate is fed forward in a direction toward the chipremoving tool so that the latter can form the next groove therein, the distance of feed corresponding to the width of the strip which is to be severed from the band or plate. Depending upon the feed of the metal band or plate, strips of varied width can be severed therefrom. It is also conceivable, by using a suitable chip-removing tool such as, for example, a pin having a hard pyramidal point, that a groove may be formed in the metal band or plate both on the retracing motion of the tool and on the forward cutting motion thereof. In such case, as well as in the case where several grooves are formed simultaneously by a plurality of tools, the feed of the band or plate to the next severing position must take place before the strips are broken off along the previously formed grooves.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as method and device for severing of metal bands or metal plates, it is nevertheless not intended to be limited to the details shown, since various modifications in the method and structural changes in the device may be made without departing from the spirit of the invention and within the scope and range of equivalents of theclaims.

The construction of the device and the method of operation thereof, however, together with additional objects and advantages thereof will be best understood from the following description when read in connection with the accompanying drawings in which:

FIG. 1 is a front elevational view of the severing device of our invention;

FIG. 2 is a cross-sectional view of FIG. 1 taken along the line II-II in the direction of the arrows;

3 is a partial longitudinal sectional view through a metal sheet in which a groove is being formed by a chip-removing tool;

FIG. 4 is an end view taken in the direction of the arrow B shown in FIG. 1 of a breaking beam constructed in accordance with the invention; and

FIG. 5 is a sectional view of a chip-removing tool holder carrying three tools located at varying levels relative to a table top.

Referring now to the drawings and particularly to FIGS. 1 and 2 thereof, there is shown device for severing a metal sheet such as a metal band or plate 1 into individual strips. The device includes a frame 2, formed of a table 3 on which the metal sheet 1 is supported, posts 4 extending upwardly along the sides of the table 3, as well as a crossbeam 5 connecting the posts 4. A lower slide or carriage 8 runs along the cross beam 5 on a horizontal flat guide or slideway 6 and a dovetailed guide or slideway 7. An upper slide or carriage 10,

the level of which is adjustable with respect to the top surface of the table 3, is disposed in substantially vertical pyramidal guides 9 formed in the lower slide or carriage 8. The upper carriage 10 carries a toolholder 11 in which is secured a pin 12 formed with a hard pyramidal ground point for producing a groove in the metal sheet I.

The severing device shown in FIGS. 1 and 2 is furthermore provided with a pivotal breaking beam 13 located on the table 3. The breaking beam 13, in the inoperative or neutral position thereof, has an upper surface 14 which is disposed in the same plane as the upper surface of the table 3, and has a longitudinal dimension corresponding to the transverse dimension of the table 3. As shown in FIG. 3, the borderline 33 between the upper surface of the table 3 and the upper surface 14 of the breaking beam 13 extends in a direction parallel to and below the bottom of the groove formed in the metal sheet 1 or below the path 34 traversed by the point of the pin 12. The breaking beam 13 has a pivot axis 15 which extends between the borderline 33 and the bottom of the groove or the path 34 traversed by the point of the pin 12 as it forms the groove in the metal sheet 1. The breaking beam 13 is provided at the ends thereof with pivots 16 suitably mounted in the frame 2 and having longitudinal central axes 17 which coincide with the pivot axis 15 of the breaking beam 13 (FIG. 4).

On the side of the table 3 facing the breaking beam 13, there is inserted in the table an intermediate layer or inlay 18 having a longitudinal dimension corresponding to the transverse dimension ofthe table 3 and having an upper surface disposed in the same plane as the upper surface of the table. Similarly, an intermediate layer or inlay 19 is inserted in the breaking beam 13 on the side of the breaking beam facing the table 3 and having a longitudinal dimension corresponding to that of the breaking beam 13, the intermediate layer 19 having an upper surface which is disposed in the same plane as the upper surface 14 of the breaking beam 13. The inlays or

intermediate layers

18 and 19 are formed of hard ceramic material so as to avoid damage thereto due to the pressure exerted by the chip-removing tool on the material of the metal sheet located below the groove formed by the tool in the metal sheet. The

intermediate layers

18 and 19 can consist, however, of other materials having hard surfaces such as, for example, surface-hardened metal.

Parallel to and on both sides of the intermediate layers on inlays l8 and 19, there are inserted retaining magnets 20 in the table 3 and the breaking beam 13, which attract the metal sheet such as the metal band of plate I, insofar as the metal sheet is magnetizable, and press the metal sheet firmly against the underlying support hereof. The retaining magnets 20 can be in the form of electromagnets which, after the strips have been broken from the metal sheet 1, are deenergized while the remaining metal sheet 1 is fed further in the advancing direction represented by the associated arrow shown in FIG. 2, and are deenergized as well during the removal of the strips. The magnets 20 can also be in the form of permanent magnets which can be short circuited in order to break the strips or remove them from the device. In order to increase the supporting pressure between the metal sheet I and its underlying support as the groove is being formed in the metal sheet, there are mounted on opposite sides, respectively, of the pin 12, compression rollers 21 loosely guided in the upper carriage 10. The compression rollers 21 are formed of magnetizable material and are spaced from the pin 12 in the upper carriage 10 a distance equal to about half the distance of the longitudinal axes of the retaining magnet 20 form the pin 12, as

shown in FIG. 2. The compression rollers 21 which are attracted by the retaining magnets 20 are especially required for pressing against the support table 3 metal bands or plates 1 that are not formed of magnetizable material. The metal sheet 1 can, however, be pressed against the underlying support thereof by other suitable means during the groove-forming and the breaking operations, particularly by means of a device, inserted parallel to both sides of the intermediate layers or inlays l8 and 19 in the table 3 and to the breaking beam 13, which applies negative pressure or suction to the underside of the metal band or plate I.

Cavities or recesses are formed in the table 3 wherein spheres 22 are rotatably disposed. The spheres 22 extend slightly out of or above the surface of the table 3 so that the metal band or plate I can be displaced in the direction of the aforementioned associated arrow shown in FIG. 2 so as to be placed in position to form the next groove therein, and need only overcome a very slight frictional force. Thus, the spheres 22 act comparably to ball bearings. Guide rails 23 displaceably adjustable in accordance with the width of the metal sheet 1 are mounted on the table 3 for lateral guidance of the metal sheet I.

The lower carriage 8 is provided with a pinion 24 and a motor 25 for driving the pinion 24. The pinion 24 meshes with a toothed rack 26 carried by the crossbeam 5 below the flat guide or slideway 6. Obviously, the movement of the lower carriage 8 can be effected by other means such as, for example, by suitable hydraulic means.

For displaceably adjusting the level of the upper carriage l0 i.e. for varying the depth of the groove to be formed in the metal sheet I, a nut 27 is horizontally disposed in the upper carriage 10, a spindle 28 provided with a thread and mounted with both ends thereof in the lower carriage 8 extending through the nut 27. The spindle 28 carries at the upper end thereof, as shown in FIG. 1, a worm gear 29 meshing with a worm 30. A housing portion 31 of the lower carriage 8 surrounds both the worm 30 and the worm gear 29. The worm 30 is simultaneously supported in the housing portion 31 and extends therefrom, the outer end thereof being surmounted by a handwheel 32 which can be suitable turned by an operator in order to raise or lower the nut 27 and accordingly the carriage l0 and the chip-removing tool 12 thereof.

In FIG. 5, there is shown a holder 11 carrying three chipremoving tools 12, 12' and 12', the tools being located at varying levels relative to a table top 14 on which a metal sheet 1 is disposed.

The advantage of the invention in the instant application is that desirably narrow strips can be severed from especially thin metal bands or plates without requiring any special straightening or burr-removing devices as have been necessary for the heretofore known methods of the general type. Since, in accordance with the method of our invention, severed strips are neither warped nor given a saberlike deformation, materials can be held to economically small tolerances. Furthermore, the strips experience no elongations of the type which have been heretofore unsatisfactorily estimable, so that subsequent measurement taking and severing of superfluous length are spared as long as the width of the metal band or metal plate corresponds to the desired length of the strips that are to be formed therefrom.

We claim:

1. Method of severing metal sheet such as bands and plates into strips which comprises feeding a metal sheet in a given direction, passing a chip-removing tool transversely to the feed direction over the sheet at a rigidly supported location thereof so as to form a groove in the sheet having a depth crossbeam connecting said upright supports, first guide means extending along said crossbeam, a substantially horizontally displaceable lower carriage guidable by said first guide means, second guide means carried by said lower carriage, an upper carriage guidable by said second guide means relative to said lower carriage for adjusting the level of said upper carriage relative to the top of said table, at least one chip-removing toll carried by said upper carriage and substantially horizontally displaceable with said lower carriage for forming a groove in a metal sheet supported on said tabletop, a breaker beam pivotally mounted on said table and having, in inoperative position thereof, an upper surface forming a common borderline with and extending in, the same place as the top of said table, said borderline being located directly beneath said chipremoving tool so that the base of a groove formed in a metal sheet by said tool is located directly above said borderline.

3. Device according to-claim 2 wherein said breaker beam has a pivot axis extending between said borderline and the base ofa groove formed in a metal sheet by said tool.

4. Device according to claim 3 wherein said breaker beam has pivot pins respectively located at the ends thereof, said pivot pins being articulatingly mounted in said frame means and having a center axis coinciding with said pivot axis of said breaker beam.

5. Device according to claim 2 including insert means inserted in said table on a side thereof facing said breaker beam, said insert means having a longitudinal dimension corresponding to the transverse dimension of said table and having an upper surface extending in a common plane with the top of said table.

6. Device according to claim 5 including insert means inserted in said breaker beam on a side thereof facing the insert means in said table, both said insert means having a relatively hard upper surface.

7. Device according to claim 6 including a plurality of retaining magnets inserted in said table and in said breaker beam on both sides of and parallel to said insert means thereof.

8. Device according to claim 7 including a pair of pressure rollers of magnetizable material loosely guided in said upper carriage, said pressure rollers being respectively located on both sides of said chip-removing tool substantially half the distance of the longitudinal dimension of a respective retaining magnet from said tool.

9. Device according to claim 2 wherein recesses are formed in the top of said table, and including rotatable spheres disposed in said recesses and extending relatively slightly beyond the surface of said table top.

10. Device according claim 2 including a plurality of chipremoving tools carried by said upper carriage one behind the other in a direction substantially parallel to said first guide means, said tools being located at varying levels relative to said tabletop for increasing the respective cutting depth thereofin the metal sheet being formed with a groove.