US3028906A

US3028906A - Apparatus for straightening discs

Info

Publication number: US3028906A
Application number: US825257A
Authority: US
Inventors: Osborn A Kershner; Harold E Olds
Original assignee: Lambert Brake Corp
Current assignee: Lambert Brake Corp
Priority date: 1959-07-06
Filing date: 1959-07-06
Publication date: 1962-04-10
Anticipated expiration: 1979-04-10
Also published as: GB908980A

Description

April 10, 1962 o. A. KERSHNER ETAL, 3,028,906

APPARATUS FOR STRAIGHTENING DISCS Filed July 6, 1959 2 Sheets-Sheet 1 INVENTORS April 10, 1962 o. A. KERSHNER ETAL 350235906 1 APPARATUS FOR STRAIGHTENING nxscs Filed July 6, 1959 2 Sheets-Sheet 2 INVENTORS Filed July 6, 1959, Ser. No. $25,257 4 Ciaims. (Cl. 153-102) The present invention relates to a novel apparatus for producing flat sheet metal articles, and more particularly to a novel apparatus for producing fiat sheet metal discs.

While it will become apparent that various articles may be produced by utilizing the apparatus of the present invention, the present disclosure will be expedited by describing the apparatus as applied to the production of sheet metal annular discs to be used in disc type brakes of the class disclosed in US. Patent 2,387,039. Such discs are usually stamped from wide sheets of stock material which is substantially flat, but apparently as a result of internal stresses, the stamped discs are usually warped to such an extent that they must be straightened before they can be used in a brake assembly. Heretofore the discs have been straightened by hand hammering but this procedure requires the expenditure of considerable amounts of skilled labor so that it is expensive and unsatisfactory. It has also been previously suggested that such discs may be straightened by compressing them with great force between opposing dies having annular ribs thereon, but such a procedure forms annular grooves in the opposite sides of the discs, which grooves raise additional problems in securing brake lining material thereto.

It is an important object ofthe present invention to provide a novel apparatus for straightening Warped or deformed sheet material discs accurately and economically.

A further object of the present invention is to provide a novel apparatus for straightening warped or deformed sheet material discs in a manner so that the finished discs have a substantially smooth surface.

Still another object of the present invention is to provide a novel apparatus for straightening discs in the manner described above, which apparatus is of simple, rugged and efficient construction.

Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings wherein:

FIG. 1 is a simplified view partially in cross section showing an apparatus incorporating features of the present invention;

FIG. 2 is a perspective view showing a disc of the type to be straightened in accordance with the present invention;

FIG. 3 is an edge view showing a warped disc of the States Patent type to be straightened in accordance with the present invention;

FIG. 4 is an exploded perspective view showing a portion of the apparatus of the present invention;

FIG. 5 is an exploded perspective view showing another portion of the apparatus adapted to be assembled in opposition to the portion shown in FIG. 4;

FIG. 6 is a perspective view showing an element of the apparatus;

FIG. 7 is an enlarged fragmentary partial sectional view taken along line 77 in FIG. 1; and

FIG. 8 is a sectional view taken generally along line 8-8 in FIG. 7.

Referring more specifically to the drawings wherein like parts are designated by the same numerals throughout the various figures, an apparatus 10 incorporating ice features of the present invention is shown in simplified form in FIG. 1. The apparatus comprises a fixture 12 including

opposing sections

14 and 16 respectively fixed on and carried by a driven shaft 13 and a ram 20. Any suitable means such as an electric motor 22 may be provided for driving the shaft 18 through suitable reduction gearing 24. The ram extends into and is actuated by a hydraulic cylinder 26 for clamping a disc to be straightened between the two

halves

14 and 16 of the fixture 12 in the manner described in detail below.

A sheet metal disc 28 of the type to be straightened in accordance with the present invention is shown in FIGS. 2, 3, 7 and 8. When the disc is to be used as a part of a brake assembly,

annular washers

30 and 32 having splined inner margins are welded to the opposite sides of the annular disc.

In accordance with the present invention, a disc 28 to be straightened is clamped between the

opposing halves

14 and 16 of the fixture 12 whereupon the fixture and the disc are rotated relative to each other. The fixture is constructed in the manner described in detail below so that during such relative rotation each circumferentially extending segment of the disc is repeatedly deformed back and forth beyond the elastic limit of the material. It has been found that as a result of this method of processing the disc, a warped disc will be substantially straightened or flattened. In fact, it has been found that, by way of example, discs may consistently be flattened to within a tolerance of 0.005 inch.

Referring specifically to FIGS. 1, 6 and 7, it is seen that the section 14 of the fixture or unit 12 comprises a main body member 34 which extends radially from a central hub 36 adapted to be fixed to the shaft 18. An annular rearwardly inclined or frusto-conical seat 38 is formed in an end face 40 of the body member 34 to provide a hearing or back up surface for a pluralityof rollers 42 which are adapted to engage and work the disc '23 in the manner described below. 'As shown best in FIG. 7, each of the rollers 42 is tapered or fl'l StO1 conical in configuration and the angle of inclination of the bearing surface 38 to the rotative axis of the body member 34 and the included angle of the taper of the rollers 42 are correlated so that the sides of the rollers opposite from the bearing surface 38 are tangent to a common plane which is perpendicular to the rota tive axis of the body member 34. Thus the rollers 42 are adapted to engage a properly positioned disc 28 with line contact substantially throughout their entire lengths.

In the embodiment illustrated, four rollers 42' are provided, which rollers are equally spaced around the bearing surface 38. In order to retain the rollers in the desired relative positions, a cage member or plate '44 is provided for overlying the rollers. Equally spaced tapered slots 46 are provided around the cage member 44 for exposing portions of the rollers which project therethrough. Of course, the width of the slots is less than the diameter of the rollers so that the'rollers cannot pass entirely through the slots. In order to absorb generally radially outwardly directed thrust loads, the body member 34 isprovided with a second annular bearing surface 48 flaring outwardly from a junction with the surface.

38 and being slightly curved or dished for accommodating rounded end surfaces 50 of the rollers. The cage member 44 is provided with a central hub portion 52 mounted on a stub shaft 54 projecting axially from the body member 34. A snap ring 56 or the like is assembled over the end of the stub shaft 54 for retaining the cage member thereon.

The section 16 of the fixture unit 12 comprises a body member 58 similar to the body member 34 and radiating from a central hub portion 60. As shown in FIG. 7,

the hub portion 60 is mounted on an end portion ofthe' 3 ram by radial and thrust bearing units 62 and 64 respectively so that the body member 58 is adapted to rotate relative to the ram 20. The ram 20 is fixed against rotation and this may be accomplished by various suitable means such as a key 66 fixed with respect to the cylinder 26 and projecting into an elongated slot 68 in the ram (see FIG. 1).

The body member 58 is provided with bearing surfaces 70 and 72 which are respectively identical to the

surfaces

38 and 48 described above and which are adapted to accommodate a plurality of rollers 74 which are identical to the rollers 42. The rollers 74 are retained in equally spaced relationship around the body member 58 by means of a cage member 76 which is shown best in FIGS. 4, 7 and 8. The cage member 76 is similar to the above described cage member 44 and comprises a plurality of tapered slots 78 through which portions of the rollers 74 project. A central hub portion 80 is formed on the cage member 76 for mounting the cage member on a reduced diameter portion 82 of the ram 20. A suitable retaining ring 84 is provided on the ram for retaining the cage member 76.

In the embodiment illustrated herein, the disc 28 is mounted between the

sections

14 and 16 and fixed against rotation during a straightening operation. This is accomplished by providing a ring 86 having peripheral splines adapted to accommodate the

splined washers

30 and 32 which are secured to the opposite sides of the disc 28 so that the disc is fixed against rotation relative to the ring. The ring 86 is in turn non-rotatably supported on the rectangular or non-circular reduced diameter end portion 88 of the ram 20 as shown in FIGS. 7 and 8.

As indicated above, the body member 34 is driven by the shaft 18. Means is provided for driving the body member 53 from the body member 34 during a workpiece straightening operation. This means comprises a plurality of fingers 90 equally spaced around and formed integrally with the periphery of the body member 34 and projecting toward the body member 58 for interengagement with similar fingers 92 projecting from the body member 58. It will be appreciated that this arrangement enables the body members 34 and 58 to be spread apart for enabling a disc to be inserted therebetween and remove therefrom without taking any special action to either connect or disconnect the driving means between the body members.

As indicated in FIGS. 7 and 8, the

cage members

44 and 76 are located with respect to each other during a workpiece straightening operation so that the rollers 44 are angularly offset from or disposed between the rollers 74. Thus when the ram 26 is actuated by the hydraulic cylinder so as to advance the section 16 toward the section 14 and thereby aggressively clamp the disc 28 between the annular series of

rollers

42 and 74,

successive rollers

42 and 74 cause successive segments of the disc to be deflected in opposite directions from a central plane. Then upon rotation of the unit 12 relative to the disc, the deflections or undulations in the disc 28 are progressively and repeatedly reversed to accomplish the straightening of the disc described above. In order to position the cage members and their associated rollers with respect to each other, fingers 94 are equally spaced around the periphery of the cage member 76 and extend axially for entry between pairs of fingers 96 provided on and extending from the periphery of the cage member 44.

While the method of straightening a disc member with the apparatusof the present invention is believed to be clear from the description above, a brief rsurn of the procedure is as follows. The hydraulic cylinder 26 which is connected with a suitable source of hydraulic fluid under pressure, not shown, is first actuated so as to retract the ram 20 and thereby the section 16 of the unit 12 from the section 14. Then a disc to be straightened is mounted on the splined ring 86 and the cylinder 26 is actuated to advance the section 16 toward the section 14 and clamp the disc between the sets of rollers. As the section of the unit 12 advances, the fingers 94 enter between the fingers 96 to loclc the cage members with respect to each other and the fingers project for interengagement with the fingers 92. Then when the pressure in the cylinder 26 has built up so that the disc is clamped between the rollers with a predetermined force, which for example, may be about five thousand pounds, a pressure responsive switch 100 (FIG. 1) connected with the cylinder 26 is actuated for energizing a suitable relay 192 for starting the motor 22. Upon rotation of the body members 34 and 58, the sets of rollers are frictionally driven around the disc 28 for repeatedly flexing and thereby straightening the disc in the manner described above. It has been found that the straightening operation can be accomplished very quickly and by way of example only it has been found that rotation of the unit 12 at about 300 rpm. for a period of 5 or 6 seconds will usually be sufiicient to accomplish the desired straightening of a workpiece.

While the preferred embodiment of the present invention has been shown and described herein, it is obvious that many structural details may be changed without departing from the spirit and scope of the appended claims. For example, the apparatus described herein may readily be modified so that the disc is rotated while the fixture or unit 12 is fixed against rotation during a straightening operation.

The invention is claimed as follows:

1. An apparatus of the type described for straightening a disc comprising means for supporting a disc to be straightened on and perpendicular to a predetermined axis, means engageable with a supported disc for ondulating the disc, said last named means including tapered rollers extending generally radially with respect to said axis and angularly ofiset from each other and disposed with their respective axes inclined with respect to said predetermined axis and with sides thereof tangent to planes perpendicular to said prcdetermined'axis and engageable with opposite sides of the disc, a first body member including a frusto-conical bearing surface sup porting one of said rollers engageable with one side of said disc, a second body member including another frustoconical bearing surface supporting another of said rollers engageable with an opposite side of the disc, first and second cage members respectively assembled in association with and relatively rotatable with respect to said first and second body members for retaining said rollers respectively in association with said first and second body members, each of said cage members extending in a plane generally perpendicular to said predetermined axis and having tapered opening means therein through which a portion of a roller associated therewith projects for engagement with the disc, and said cage members including cooperable axially interengageable means for releasably locking the cage members in predetermined relationship with respect to each other.

2. An apparatus of the type described for straightening discs comprising means for supporting a disc on and perpendicular to a predetermined axis, a first body member axially aligned with said axis, a second body member axially aligned with said axis, a first series of annularly spaced rollers assembled with and bearing against said first body member and having sides opposite from said first body member tangent to a plane disposed perpendicular to said axis for engaging one side of the disc, a second series of annularly spaced rollers assembled with and bearing against said second body member and having sides opposite from said second body member substantially tangent to a plane perpendicular to said axis for engaging a side of the disc opposite from said first mentioned rollers, the rollers in said first series being angularly offset from the rollers in said second series for undulating the disc when the disc is clamped between the two series of rollers, said rollers being tapered, said body members including first frusto-conical bearing surfaces engageable with sides of said rollers and second annular bearing surfaces projecting from adjacent outer margins of said first surfaces and engaging generally radially outer ends of the rollers, first and second cage members respectively assembled in association with and relatively rotatable with respect to said first and second body members for retaining said first and second series of rollers, said cage members having opening means therein through which portions of the rollers associated therewith project for engagement with a disc, and cooperable means on said first and second cage members for releasably locking the cage members in predetermined relationship with respect to each other.

3. An apparatus, as defined in claim 2, which includes means for advancing and retracting said body members with respect to each other for clamping and releasing a disc therebetween, and means for relatively rotating said body members and said disc supporting means for relatively advancing said rollers around the disc.

4. An apparatus, as defined in claim 3, which includes fluid pressure means for relatively advancing said body members with respect to each other for clamping the disc, motor means for rotating the body members when the disc is clamped, and pressure sensitive switch means associated with said fluid pressure means for energizing said motor after a disc is clamped with a predetermined pressure.

References Cited in the file of this patent UNITED STATES PATENTS 698,351 Arnold Apr. 22, 1902 1,601,795 Glover Oct. 5, 1926 1,672,208 Glover June 5, 1928 2,398,227 Hubbert Apr. 9, 1946 2,724,625 White Nov. 22, 1955