US3908435A

US3908435A - Edge bending press

Info

Publication number: US3908435A
Application number: US528616A
Authority: US
Inventors: Jr Miles Augustus Bowman; Christopher James Hampton; Paul Henry Schock
Original assignee: Dana Inc
Current assignee: Dana Inc
Priority date: 1974-12-02
Filing date: 1974-12-02
Publication date: 1975-09-30
Anticipated expiration: 1992-09-30
Also published as: BR7505396A; CA1034857A

Abstract

Disclosed is an apparatus for bending a workpiece while retaining the same in a single plane. An exemplary use for such an apparatus is to bend a flat sheet of steel prior to blanking and forming operations and preparatory to its being assembled into a vehicle frame. Such an operation, referred to in the art as edge bending is known to conserve materials but is difficult to achieve with prior art devices and therefore has not been widely adopted. The present apparatus overcomes many of the problems with the prior art devices. It includes a base and a bed member parallel to and movable toward and away from the base. One or more push blocks are supported by the bed and guided for movement transversely thereof. A linkage is provided to move the push blocks across the bed as the bed is moved toward and away from the base. The apparatus is designed for operation with a conventional hydraulic or mechanicam press and the bed is moved toward the base by the press. The apparatus allows conversion of a conventional stamping press to an edge bending press. The ram of the press need only be fitted with a flat plate which, in conjunction with the bed of the present apparatus serves to restrain the workpiece in the desired plane.

Description

United States Patent 1191 Bowman, Jr. et al.

[451 Sept. 30, 1975 1 1 EDGE BENDING PRESS [75] Inventors: Miles Augustus Bowman, Jr.,

Reading; Christopher James Hampton, Boyertown; Paul Henry Schock, Reading. all of Pa.

[73] Assignee: Dana Corporation, Toledo, Ohio [221 Filed: Dec. 2, 1974 1211 Appl. No.: 528,616

Primary E.\'aminerC. W. Lanham Assistant Examiner-Gene P. Crosby Attorney, Agent, or Firm-Robert E. Pollock [57] ABSTRACT Disclosed is an apparatus for bending a workpiece while retaining the same in a single plane. An exemplary use for such an apparatus is to bend a flat sheet of steel prior to blanking and forming operations and preparatory to its being assembled into a vehicle frame. Such an operation, referred to in the art as edge bending is known to conserve materials but is difficult to achieve with prior art devices and therefore has not been widely adopted. The present apparatus overcomes many of the problems with the prior art devices. It includes a base and a bed member parallel to and movable toward and away from the base. One or more push blocks are supported by the bed and guided for movement transversely thereof. A linkage is provided to move the push blocks across the bed as the bed is moved toward and away from the base. The apparatus is designed for operation with a conventional hydraulic or mechanieam press and the bed is moved toward the base by the press. The apparatus allows conversion of a conventional stamping press to an edge bending press. The ram of the press need only be fitted with a flat plate which, in conjunction with the bed of the present apparatus serves to restrain the workpiece in the desired plane.

14 Claims, 4 Drawing Figures US. Patent Sept. 30,1975 Sheet 1 GM 3,908,435

US. Patent Sept. 30,1975 Sheet 2 of4 3,908,435

Sept. 30,1975 Sheet 3 of 4 US; Patent Sheet 4 of 4 Patent Sept. 30,1975 3,908,435

xi so EDGE BENDING PRESS 7 BACKGROUND OF THE INVENTION This invention relates to material bending tools and more particularly to such tools adapted to bend a workpiece in a single plane.

In certain manufacturing operations it is desirable to deform a sheet of material laterally between the planes defining the top and bottom faces thereof. Typical of such operations is bending sheets which are subsequently formed into vehicle frames. Such a forming procedure is known in the art as edge bending and will be so referred to hereinafter. Although principally applied in metal forming it is apparent that edge bending can be employed with any yieldable material which can be permanently deformed.

Presses for edge bending have been available for some time. US. Pat. No. 1,340,138 which issued May 11, 1920 to H. Miller illustrates one such press.

While generally satisfactory, such edge bending presses have certain shortcomings. A major drawback to known edge bending presses is that they are adapted only to such service and cannot be readily modified'to serve as conventional stamping presses.

Further, many of the prior art edge bending presses exert substantial unbalanced lateral forces and therefore require massive restraint members to transmit the unbalanced lateral forces from the movable ram to the fixed bed of the machine. Such members often obstruct clear passage of the formed material through the machine.

It is, therefore, an object of the present invention to provide an edge bend press which is readily convertible to a conventional stamping press.

It is a further object of the invention to provide tooling which can be installed in a conventional stamping press to convert the same for an edge bending operation.

It is another object of the invention to provide an edge bend system in which the lateral forces are substantially balanced thereby minimizing the size of the structural members required for a given bending operation.

It is still another object of the invention to provide such a mechanism which allows unobstructed removal of the workpiece upon initial separation of the ram and bed.

SUMMARY OF THE INVENTION The above and other objects are achieved in the edge bending press apparatus of the present invention. The press includes a base and a bed member generally parallel to the base. Guide means are provided to allow the bed member to move toward and away from the base and prevent other relative movement (e.g., cooking and lateral movement) therebetween. At least one and generally a plurality of push blocks are supported by the bed member, extend thereabove and are guided for movement transversely thereof. A linkage means is provided connecting the base of each of the push blocks to move the push blocks transversely of the bed as the bed moves toward and away from the base.

Such a device can simply be placed within a conventional stamping press of appropriate size and power. The base of the device rests on the bed of the press. A flat platen mounted to the press ram contacts the bed of the device during operation to transmit the forces necessary to move the linkage transversely.

In a preferred embodiment the linkage means comprises a lever means. Such a linkage is not only mechanically simple, but also, in the context of the present invention, provides an increasing force asv such a force is required at the limits of the bending.

A further preferred feature of the invention is the use of plural push blocks with alternate ones thereof operating in opposition. Such an arrangement, particularly when used in combination with a lever type actuator balances the lateral forces and generally allows the use of members in tension or compression thereby reducing the requisite mass of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS While the specification concludes with claims which particularly point out and distinctly claim the subject matter forming the present invention it is believed that the same will be better understood with reference to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a partial schematic isometric view of a preferred embodiment of the invention;

FIG. 2 is a vertical cross-sectional view of the invention generally corresponding to a view taken along line 22 in FIG. 1;

FIG. 3 is a vertical cross-sectional view generally corresponding to FIG. 2 showing the apparatus in its final working position, and;

FIG. 4 is a plan view, from above, of the apparatus of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to the drawings, FIG. 1 thereof illustrates a preferred embodiment of the invention in a partially schematic form suited to the ready understanding thereof. The basic support for the apparatus is a base designated generally by the numeral 10 which is adapted for support on the table of a generally conventional stamping press. A bed member, designated generally by the numeral 20 is guided and supported, as will hereinafter more fully be described, so as to be movable toward and away from the base 10 while remaining parallel thereto. Such support is primarily provided by guide members, designated generally by the numeral 30, which extend upward from the base 10 along the vertical faces of the bed 20.

Preferably the base 10 defines a plurality of apetures 11 through which travel cushion pins 12. Such pins are generally conventional in stamping presses equipped with cushions and serve to minimize shock loading and control the rate of application of press force. Normally in using the apparatus of the present invention to adapt a stamping press to edge bending duty the cushion pin arrangement and control can be retained; the pins need only be modified in length as may be required for a particular application. An apeture 11 is associated with each pin and the bed 20 may include pockets or the like to receive the pins. The present invention can also include a yieldable support in the base of the tooling to allow the use thereof in a press not provided with cushions.

The bed supports one or more push block's, designated generally by the numeral 21, ivhich, in the illustrated and preferred embodiment iIiElude sll 'e members 22 and forming blocks 23. The upper face 24 of the bed member 20 is preferably made of hard steel and the slide member 22 is therefore preferably hard faced steel or faced with a material such as bronze or an alloy thereof which slides readily thereon. As will be seen and hereinafter more fully described the material to be formed rests on the slide members 22 and the same are moved laterally in the direction of the arrows as the bed 20 moves relative to the base 10 upon application of press pressure.

Any suitable means can be provided to cause the push blocks to move laterally upon relative motion between the bed member 20 and base 10. The preferred means is a link arrangement comprising links 25 which are pivotally connected to the base 10 via pins 26 and to the push blocks by similar pins (not shown). Such a linkage means is not only very simple but also, in the present apparatus configuration, provides a highly desirable mechanical advantage as will hereinafter and more fully be described.

In the preferred embodiment. multiple push blocks are used and alternate ones thereof move laterally in opposite directions. Such an arrangement minimizes or eliminates altogether any net lateral force in the apparatus and thereby eliminates the need for any additional means for providing lateral stability. The push blocks 21 can be of any desired width and various ones of the blocks can be of different widths within the apparatus. Both the widths of the push blocks 21 and the geometry of the forming blocks 23 will, of course, be dictated by the final desired configuration of the bent workpiece. Spacer blocks designated generally by the numeral 40 are preferably but optionally provided between alternate ones of the push blocks 21. The spacer blocks 40 serve to guide the push blocks 21 and also serve in conjunction with the slide members 22 to support the workpiece. Plates 41 are provided in lateral spaced relationship at either end of the spacer blocks 40 to maintain the requisite spacing between the ram plate and forming blocks 23 to prevent excessive friction therebetween.

The apparatus shown in FIG. 1 is placed on the table of a press and the ram of said press is provided with a flat platen so sized as to substantially cover the bed 20. The workpiece is put in place atop the spacer blocks 40 and push blocks 21 and the press ram is lowered. Upon contacting the plates 41 and forming blocks 23 the press platen forces the bed 20 and associated structure downwardly against the urging of the cushion pins. The workpiece is maintained against vertical deformation by the clamping pressure between the press platen and the upper surfaces of the slide members 22 and spacer blocks 40. In this connection, it should be noted that the forming blocks 23 and plates 41 are preferably slightly greater in thickness than the material to be formed thereby assuring that such members transmit all of the vertical forces on the press while not providing clearance between the press platen and the tops of the slide members 22 and spacer blocks 40 of such size as to allow substantial vertical deformation of the workpiece.

As the press platen continues downward the push blocks 21 move laterally in the direction of the arrows as a result of the action of the link mechanisms.

FIG. 2 of the drawings is a detailed vertical cross sectional view of the apparatus of FIG. 1 taken generally along the line 22. A block 13 is affixed to the base 10 by any suitable means such as bolts 14 and provides a support for the pins 26. The bed 20 preferably includes top plate 24 and bottom plate 26, side plates 28 and intermediate supports in the form of vertically oricnted eye-beams 29. The bed 20 is slotted laterally to accommodate the depending portion of the slide member 22 which receives the pin 26. The platen 50 preferably includes a replacable wear plate 51 affixed thereto by any suitable means such as bolts 52. The preferred material for the wear plate 41 is hard steel. Similar wear plates can also be provided on the bed 20 adjacent to and supporting the slide members 22.

With continuing reference to FIGQ 2, the bed 20 is held at the upper extreme of its travel by the cushion pins 12 prior to the actuation of the press and lowering of the ram and platen 50. While the bed 20 is in this position. the workpiece W is placed thereon and between the opposing forming blocks 23. For ease of loading the forming blocks 23 are. at this time, widely separated relative to the width of the workpiece W and the links 25 are at an angle 0 of about 60 from the horizontal. The angle 0 can, of course be varied from machine to machine as desired to provide the preferred force/distance relationship for any application. Furthermore multiple positions for pins 26 in blocks 13 may be provided for adjustability.

The guide members shown diagramatically in FIG. 1 preferably take the form of vertical members 31 supported on the base and extending in pairs on either side of each of and closely adjacent to each of a plurality of lateral extensions 32 on the sides of the bed 20. Such an arrangement allows the bed to move freely toward and away from the base 10 while substantially eliminating any other relative movement therebetween. Replacable wear plates can be provided on the vertical members 31 or abutting portions of the bed 20 as may be required in any particular application.

FIG. 3 shows the apparatus in the position it assumes at the end of the travel of the platen 50. At this point the links are at an angle 0 of about to horizontal. Although not critical, it is preferred that the angle 0 be from about 20 to As will be recognized the link mechanism provides a force multiplication effect which is highly desirable. For instance, if the final angle 0' is 30 the force multiplication (ignoring friction) is 3; i.e., equal to the contangent of 0. Reduction in the angle 0 rapidly increases the final force multiplication. Further it will be noted that as the bending nears completion and the bending force requirement is at its maximum, the angle 0 approaches its minimum and the contangent reaches its maximum value. The apparatus, therefore, provides the maximum bending force concurrent with the maximum need therefor.

FIG. 4 is a plan view of the apparatus of FIG. 3 with the platen 50 removed for clarity. As shown, the apparatus includes four push blocks 21 and five spacer blocks 40 although it will be appreciated that any number of such elements can be employed. In forming relatively long workpieces such as components for vehicle frames a plurality of units such as that shown in FIG. 4 will be used and to that end connection means in the form of cutouts 60 are provided on the sections to allow them to be connected to one another by suitable clamps to form a long integral unit. It will be recognized that such an approach provides a ready means to modify the overall apparatus to allow the use of common parts in setups for related finished parts.

As can be seen the forming blocks 23 can be flat, angular or curved in plan view to achieve the desired final shape of the workpiece. Further each push block 21, with its associated forming block 23, and each spacer block 40 can be any desired width.

What is claimed is:

1. An apparatus for bending a workpiece in a single plane comprising a base, a bed member generally parallel to said base, guide means to permit said bed member to move toward and away from said base and prevent other relative movement therebetween, a push block supported by and extending above said bed and guided for sliding motion transversely thereof and linkage means connecting said base and said block to move the latter across said bed as said bed is moved relative to said base.

2. The apparatus of claim 1 wherein said linkage means comprises a lever means.

3. The apparatus of claim 1 having a plurality of push blocks, each push block havinga linkage means said linkage means being so arranged as to move alternate ones of of said push blocks in opposite directions.

4. The apparatus of claim 3 wherein said linkage means comprises a lever means.

5. The apparatus of claim 1 additionally including cushioning means connected to said bed and extending through said base.

6. The apparatus of claim 5 wherein said linkage means comprises a lever means.

7. The apparatus of claim 5 each having a linkage means said linkage means being so arranged as to move alternate ones of said push blocks in opposite directions.

8. The apparatus of claim 7 wherein said linkage means comprises a lever means.

9. The apparatus of claim 1 wherein said push block comprises a slide portion and a shaped forming portion and said slide portion rests on said bed.

10. The apparatus of claim 9 including a plurality of push blocks and spacer blocks fix interposed therebetween and fixed to said bed.

11. The apparatus of claim 9 wherein said linkage means comprises a lever means.

12. The apparatus of claim 9 each having a linkage means said linkage means being so arranged as to move alternate ones of said push blocks in opposite directions.

13. The apparatus of claim 12 wherein said linkage means comprises a lever means;

14. The apparatus of claim 13 including a plurality of push blocks and spacer blocks interposed therebetween and fixed to said bed.

Claims

2. The apparatus of claim 1 wherein said linkage means comprises a lever means.

3. The apparatus of claim 1 having a plurality of push blocks, each push block having a linkage means said linkage means being so arranged as to move alternate ones of of said push blocks in opposite directions.

4. The apparatus of claim 3 wherein said linkage means comprises a lever means.

6. The apparatus of claim 5 wherein said linkage means comprises a lever means.

8. The apparatus of claim 7 wherein said linkage means comprises a lever means.

13. The apparatus of claim 12 wherein said linkage means comprises a lever means.