US3597952A - Planetary roller leveler for sheet metals - Google Patents

Abstract

Two backup rolls having work rollers arranged on the peripheral surface thereof and adapted to roll thereon are arranged adjacently one above the other. The ends of said work rollers on each said backup roll are supported by a pair of holding disks, and a certain relative speed of rotation is given to said pair of holding disks and the backup roll so that the work rollers simultaneously rotate about their own axis and about the axis of the backup roll. The machine operates as a leveler which levels metal sheet passing between the rotating work rollers.

Description

References Cited UNITED STATES PATENTS Inventor Choichiro Soda Tokyo, Japan 843,305

[21] Appl. No.

Filed 2,565,780 8/1951 [221 3,208,259 9/1965 Maier.........,. F 3,210,981 l0/l965 Sendzimir.................... (73] Ass1gnee Agency of lndustnalscience 8: Technology 3 360 973 ["968 Comer Tokyohpan Primary ExaminerMilton S. Mehr Altorneyl(urt Kelman July 24, 1968 Japan 43/52290 ABSTRACT: Two backup rolls having work rollers arranged on the peripheral surface thereof and adapted to roll thereon are arranged adjacently one above the other. The ends of said work rollers on each said backup roll are supported by a pair zclumsnnrawmg of holding disks, and a certain relative speed of rotation is [52] US. given to said pair of holding disks and the backup roll so that 32 Priority [54] PLANETARY noun-3n LEVELER FOR SHEET METALS the work rollers simultaneously rotate about their own axis Int. and about the axis ofthe backup roll. The machine operates as [50] Field of a leveler which levels metal sheet passing between the rotating work rollers.

Patented Aug. 10, 1971 PRIOR ART INVENTOR c: Hora R0 50 0A Patented Aug. 10, 1971 3 Shegts-Sheet 2 8 no 8% .8 8 R 0 n wmw Patented Aug. 10, 1971 3,591,952

3 Sheets-Sheet 5 v INVENTOR Cl-FOlCtflRO SODA I AGENT PLANETARY ROLLER LEVEL ER FOR SHEET METALS The present invention relates to a planetary roller leveler for sheet metals.

The known roll levelers for sheet metals comprise linear rows of work rollers arranged in two different horizontal planes, each of said rollers being connected to a universal joint and adapted to be driven by a motor. When a sheet of metal to be leveled is passed between said rows of work rollers, it is subject to repeated plastic deformation by the rotation of said work rollers and thus made truer in flatness.

When a material small in thickness or high in elasticity is to be flattened by such a roller leveler, the diameter of the work rollers must be decreased. When this is done, the rollers become less rigid with the decreasing in diameter. To compensate for this, backup rolls are usually arranged outside of the work rollers.

Since reduction ofthe roller diameter also requiresdimensional reduction of bearings and joints and since special devices for reinforcement must be added, levelers for such materials as mentioned above have a certain limit both in size and accuracy. The rollers of the smallest roller levelers now on the market are no less than mm. in diameter. Thus, such materials are difi'icult to level and the accuracy of the leveling is poor.

Thin and highly flat sheets of material of 0.1 mm. or less in thickness are presently in demand as a result of the refinement and miniaturization of machines and apparatuses in the electronic and other industries. As a tension leveler wherein sheet metal is leveled by rollers while being subject to tension has recently been developed, long strips of considerably small thicknesses can now be leveled. But it is impossible to apply such tension method to small materials such as punched parts so that such sheets of under 0.1 mm. in thickness have hitherto been impossible to level from end to end.

The principal object of the present invention is to provide a leveler capable of leveling sheet metal of under 0.1 mm. in thickness or thin and highly elastic materials with high accura- Another object of the present invention is to provide a leveler capable of leveling with ease small parts made from thin sheet metal which cannot be leveled by conventional levelers. v i

According to the present invention, two backup rolls having work rollers arranged on the peripheral surface thereof and adapted to roll thereon are arranged adjacently one above the other. The ends of said work rollers on each said backup roll are supported by a pair of holding disks, and a certain relative speed of rotation is given to said pair of holding disks and the backup roll so that the work rollers simultaneously rotate about their own axis and about the axis of the backup roll. Thus a sheet of metal passing through the gap between the upper and lower rotating work rollers is leveled. This allows the manufacture of a leveler whose work rollers have a diameter of 2 mm. without causing a reduction in the rigidity of the rollers as is the case with the conventional levelers, so that thin and highly elastic materials or thin and small-sized materials may be leveled with high accuracy. This advantage is attributable to the fact that the work rollers have a great resistance to being bent as they are rolling along the highly rigid backup rolls in contact therewith.

When work rollers; of 2 mm. in diameter are used in the leveler according to the present invention, the minimum sheet thickness which can be leveled is one-half or one-third of that of the conventional levelers. Spring plates of nickel-silver, phosphor bronze and stainless steel of o.l0.08 mm. in thickness for electronic telephone exchanges, magnetic materials of -10 p. in thickness for the memories of electronic computers, 20 p. copper plates for printed circuits, 0.08 mm. copper spring plates for diaphragms, etc, none of which could mechanically be leveled, can be leveled easily and highly accurately. This will greatly ease the production of precision apparatuses.

Other objects and features of the present invention will become apparent from the following detailed description in reference to the accompanying drawing in which:

FIG. 1 is an illustrative view of the principle of a conventional leveler;

FIG. 2 is an illustrative view showing the relationship of the respective rotations of the work rollers and backup rolls according to the present invention;

FIG. 3 is a side elevational view of the leveler according to the present invention;

FIG. 4 is a front elevational view of the leveler of FIG. 3;

FIG. Sis a plane view taken along the line VV of FIG. 3;

FIG. 6 is an enlarged sectional view through the shaft of the backup roll; and

FIG. 7 is an illustrative view of an embodiment of the driving system of the present invention.

In FIG. 1, two groups of work rollers 1 are arranged linearly one above another and each of said work rollers is rotated by an electric motor not shown. A sheet of metal 3 is leveled by being passed between the rows of said rotating work rollers. When, for example, a high elastic material is to be leveled, the diameter of the work rollers must be lessened. Since the rigidity of the rollers decreases as the diameter thereof decreases, backup rolls 2 are arranged on the outside of the work rollers l to compensate for the loss of rigidity. However, the diameter of the rollers cannot be lessened beyond a certain value because of construction and accuracy considerations, for the backup rolls and joints must be also made small sized if the work rollers are made thinner.

Referring now to FIG. 2-6, backup rolls 4 and 4' are arranged adjacently one above the other on a machine base 6 and supported by their projecting shafts 5 and 5 on upper and lower bearing boxes 7 and 7.

The lower backup roll 4' is driven by a speed change gear 40 through-the shaft 5 and an universal joint 41'. The upper backup roll 4 rotates at the same speed as the lower backup roll 4' with the help of a gear wheel 8 secured to the shaft 5, transmission gear wheels 9 and 10 and a gear wheel 11 secured to the shaft 5'.

Pair of holding disks 12, 12' are provided opposed to each other one on each end of the backup roll 4, 4' and secured to gear wheels 13, 13' rotatably mounted on the shaft 5, 5' through bearings by means of screws 30.

Arranged between the opposed holding disks 12, 12' are small- diameter work rollers 14, 14 adapted to roll on the peripheral surface of the backup roll 4, 4'.

To ensure that the work rollers 14, 14' revolve their own axis with the aid of the frictional force of the backup roll 4, 4', grooves 15 are provided on both ends of the work rollers 14, 14' and bands 17' of of metal or high-tensile plastics are threaded over the pulleys 16 at the end of arms 20, pulleys 16 at the end of levers 18 and said grooves 15. The tension of the bands 17 can be adjusted by means of springs 19 provided at the opposite end of levers 18.

The gear wheels 13, 13"to which the holding disks 12, 12' are secured rotate at the same speed through gear wheels 24 and 25 provided on connecting plates 21 and 22 which have one end pivotally mounted on the shafts 5, 5'. The connecting plates 21 and 22 are connected by a connecting plate 23 at one end of which is on the shaft 26 of the gear wheel 24 and at the other end of which is on the shaft 26' of the gear wheel 25. The revolution of the speed change gear 40 is transmitted through an intermediate gear wheel 29, a gear wheel 27 rotatably mounted on the shaft 5' and a gear wheel 28 secured to the-shaft 26' in parallel with the gear wheel 25.

When the upper and lower groups of work rollers 14, 14 are in a position wherein they butt against each other, it is necessary to locate one work roller of one group in the center between two adjacent rollers of the other group. For this purpose a shaft 31 is provided extending from the tip of one connecting plate 22 to the tip of the other connecting plate 22 and one end of threaded shaft 32 having a handle at the middle thereof is screwed into machine base 6 while its other end contacts said shaft 31 at the middle thereof. The height of said shaft 31 is changed by turning said handle to cause the connecting plates 21 and 22 to rotate round the shafts and 5'. respectively. thereby allowing fine adjustment of the position of the work-roller groups relative to each other.

To adjust the gap between the upper and lower groups of work rollers l4, 14' arranged around the upper and lower backup rolls 4, 4' In accordance with the thickness of the sheet to be leveled. the bearing box 7' supporting the lower backup roll 4' is fixed, while the bearing box 7 supporting the upper backup roll 4 can be adjusted in height along a guide on the machine base 6 through a threaded rod 33 extending through the machine base 6 and pressing at one end against the top of said bearing box 7, a worm gear 34 secured to the other end of said rod, a wonn 35 engaged with said worm gear and a handle 36 for turning said worm 35.

A plate 37 for holding the sheet metal to be worked is fixed to the machine base 6.

Referring to FIG. 7, the revolutions of motor 38 are transmitted through a reduction gear 39 to the speed change gear 40, which controls the speed ratio of the backup rolls 4, 4' and the holding disks 12 to a desired value. Naturally, the motor, reduction gear and speed change gear may be accommodated within the machine base.

When the upper backup roll 4 and holding disks ]2 and the lower backup roll 4 and holding disks [2 are rotated in the same direction as shown by arrows in FIG. 2, the groups of work rollers 14 and 14' revolve about their own axis with the help of friction against the backup rolls 4 and 4 and simultaneously about the axis of the backup rolls 4 and 4', respectively. In this case, if there is no slippage between the work rollers and the backup roll, the relationship between the number of revolutions of the backup rolls N,, the number of revolutions of the holding disks N and the number of revolutions of the work rollers N, in rpm. is expressed by the following:

wherein D is the diameter of the backup rolls in mm., and

D is the diameter of the work rollers in mm. Further, a sheet of metal inserted between the upper and lower groups of work rollers 14 and 14' which revolve about the axis of the backup rolls while revolving about their own axis is passed at a speed thereby to be leveled by repeated plastic bending deformation. (when v 0, the sheet moves to the right and vice versa.)

The amount of intermesh of the upper and lower work rollers takes the maximum in the middle range where the two groups of rollers are closely opposed. Hence, the bending moment applied to the sheet increases gradually to the maximum as the sheet proceeds and thereafter decreases gradually until the flatness of the sheet is attained.

The minimum sheet thickness which can be leveled by the present invention can be expressed by the following equation in regard to the proof stress 0-,, and longitudinal elastic modulus E of the material and the diameter of the work rollers D wherein a is a constant dependent upon the tensile force applied to the sheet and normally about 8 without tension. With no tensile force applied to the sheet. it follows from the above equation that !=0.04 I) for phosphor bronze for springs of 0,, kg./mm. and 5 12.600. lf D,=2 mm., r-=0.08 mm., while !=0.2 mm. for 0 5 mm Further. for stainless steel of #0 kg./mm !=().08 mm. for D,=5 mm. and indeed t=0.03 mm. for D,=2 mm.

Thus, when work rollers of 2 mm. in diameter are used in the leveler according to the present invention. the minimum sheet thickness which can be leveled can be reduced down to one-half or one-third ofthat of the conventional levelers.

Furthermore, it is also possible to use the leveler according to the present invention as a so-called tension leveler by applying tension to the sheet in the longitudinal direction. In this case, in contrast with conventiona levelers, It is possible by varying the speed ratio of the backup rolls and the holding disks and by thus varying the frequency at which the sheet is bent to freely adjust not only the degree of flatness obtained but also the degree of reduction of sheet thickness.

While there has been described in connection with the preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is aimed, therefore, to cover in the appended claims all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim is:

l. A planetary roller leveler for sheet metals comprising;

a machine base,

a pair of backup rolls arranged adjacently one above the other and having work rollers arranged on the peripheral surface thereof, said work rollers being adapted to roll or the peripheral surface of said backup rolls,

holding disks for holding said work rollers at both ends thereof, said disks being rotatably mounted on the shafts of said backup rolls.

means for pressing said work rollers against said backup rolls, means for centering one work roller of one of the upper and lower groups of work rollers between two adjacent rollers of the other group,

means for adjusting the gap between the upper and lower groups of work rollers,

means for rotating said pair of backup rolls, and

means for rotating said holding disks, whereby said backup rolls and holding disks are rotated relative to each other for causing said work rollers simultaneously to revolve about their own axis and the axis of said backup rolls; wherein a sheet of metal to be leveled is allowed to pass between the upper and lower groups of said rotating work rollers.

2. The leveler as set forth in claim 1, wherein said means for pressing said work rollers against said backup rolls comprises high tensile bands threaded on grooves provided on both ends ofsaid work rollers and pulleys attached to said machine base.

Claims (2)

1. A planetary roller leveler for sheet metals comprising; a machine base, a pair of backup rolls arranged adjacently one above the other and having work rollers arranged on the peripheral surface thereof, said work rollers being adapted to roll on the peripheral surface of said backup rolls, holding disks for holding said work rollers at both ends thereof, said disks being rotatably mounted on the shafts of said backup rolls, means for pressing said work rollers against said backup rolls, means for centering one work roller of one of the upper and lower groups of work rollers between two adjacent rollers of the other group, means for adjusting the gap between the upper and lower groups of work rollers, means for rotating said pair of backup rolls, and means for rotating said holding disks, whereby said backup rolls and holding disks are rotated relative to each other for causing said work rollers simultaneously to revolve about their own axis and the axis of said backup rolls; wherein a sheet of metal to be leveled is allowed to pass between the upper and lower groups of said rotating work rollers.

2. The leveler as set forth in claim 1, wherein said means for pressing said work rollers against said backup rolls comprises higH tensile bands threaded on grooves provided on both ends of said work rollers and pulleys attached to said machine base.

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