US2860685A

US2860685A - Method and apparatus for sequentially forming sheet metal with spaced dies

Info

Publication number: US2860685A
Application number: US584708A
Authority: US
Inventors: Mcdonald John
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-05-14
Filing date: 1956-05-14
Publication date: 1958-11-18
Anticipated expiration: 1975-11-18

Description

Nov. 18, 1958 J. MCDONALD 2,850,635

METHOD AND APPARATUS FOR SEQUENTIALL! FORMING SHEET METAL WITH SPACED DIES Filed May 14, 1956 2 Sheets-Sheet 1 m m i 7 N k F 7 m m T n F \41 o r I W INVENTO JOHN MCDONALD BY W".,

Nov. 18, 1958 MCDONALD 2,860,685

METHOD AND APPA us FOR SEQUENTIALLY FORMING SHEET METAL WITH SPACED DIES Filed May 14, 1956 2 Sheets-Sheet 2 JZ H-Z F/ /5 g INVENTOR.

JOHN M DONALD United States Patent METHOD AND APPARATUS FOR SEQUENTIALLY FORMING SHEET METAL WITH SPACED DIES John McDonald, Westlake, Ohio, assiguor of one-half to Bruce B. Krost, Cleveland, Ohio Application May 14, 1956, Serial No. 584,708

13 Claims. (Cl. 153-21) My invention relates to apparatus and method for forming sheet metal into desired cross-sectional conformation. 1

An object of my invention is to press a strip of sheet metal of relatively flat or simple form to a desired crosssectional form.

Another object is the provision for modifying the cross-sectional form of a strip of sheet metal without the use of rollers usually used to roll sheet metal into desired cross-sectional conformation.

Another object is the provision of apparatus and method for forming complex cross-sectional forms in a strip of sheet metal with an economy of apparatus and manufacturing steps utilized.

Another object is the provision for forming a strip of sheet metal into forms not readily obtainable with the use of mating rolls.

Another object is the provision of apparatus and method for pressing sheet metal into desired cross-sectional conformation and having blind arches or construction not readily obtainable by the use of prior apparatus and methods.

Another object is the provision for forming metal by a series of spaced mating die members so arranged and constructed as to provide desired results in the form of the sheet metal with a maximum of economy and efliciency. r

Another object is the provision of apparatus and method for producing results not heretofore obtainable.

Other objects and a fuller understanding of my invention may be had by referring to the following description and claims taken in conjunction with the accompanying drawings, in which:

Figure 1 is a longitudinal elevational view of apparatus embodying my invention;

Figure 2 is an enlarged plan view of a length of sheet metal strip going through its various stages of forming from its simple fiat form to its desired conformation of more complex nature;

Figure 3 is a cross-sectional view of the strip of sheet metal taken through the line 3-3 of Figure 2;

Figure 4 is a cross-sectional view of the strip of sheet metal taken through the line 4-4 of Figure 2;

Figure 5 is a cross-sectional view of the strip of sheet metal taken through the line 5-5 of Figure 2;

Figure 6 is a cross-sectional view of the strip of sheet Figure 8 is a cross-sectional view of the strip of sheet metal taken through the line 8-8:of Figure 2;

Figure 9 is a cross-sectional view of the strip of sheet I l metal taken through the line 9-9 of Figure 2;

Figure 10 is a cross-sectional view of the strip of sheet metal taken through the line 10-10 of Figure2; Figure 11 is an enlarged fragmentary view of one of the pairs of mating die members in the apparatus shown r in Figure 1 and illustrates the front face of the last pair of mating die members in the sequence located adjacent the right-hand end of the apparatus shown in Figure 1;

Figure 12 is an enlarged cross-sectional view of the pair of mating die members shown in Figure 11 and taken through the line 12-12 of Figure ll;

Figure 13 is an enlarged sectional view taken through the line 13-13 of Figure 11;

(In Figures 12 and 13 for purposes of clarity of illustration the strip of sheet metal is not shown between the mating die members.)

Figure 14 illustrates a modified form of mating die members when a floating mandrel is utilized in the forming of the strip of sheet metal; and

Figure 15 is another modified form of mating die members in which blind arches or open spaces are formed in the strip of sheet metal Without the utilization of a floating mandrel.

My apparatus is carried on a rigid frame denoted generally by the reference character 21. The frame 21 has upright standards or legs 22 and a bed plate or bottom supporting beam 23 carried by the legs 22. Positioned above and spaced from the bedplate 23 is a longitudinal beam 24. The beam 24 and bedplate 23 are substantially parallel to each other and extend longitudinally of the frame 21. A shaft 25 journaled on the frame 21 is driven by a belt 28 which drivingly engages a pulley 27 on the shaft 25 and a driving pulley 29 which, in turn, is driven by an electric motor 30 supported on the frame 21. Thus, the motor 30 through the pulleys 29 and 27 and connecting belt 28 rotates the shaft 25.

Adjacent the opposite ends of the shaft 25 where it is journaled to the frame 21, there are eccentric bearing mechanisms 26 which are so interconnected with the 1 shaft 25 and beam 24 as to reciprocate the beam 24 in a vertical direction, that is, upwardly and downwardly, relative to the frame 21 as the shaft 25 is rotated. asmuch as the eccentric bearing mechanisms 26 are of the usual form for translating rotary motion into reciprocating motion, and commonly utilized in reciprocating die mechanisms, the detailed construction of the eccentric bearing mechanisms 26 has not been illustrated.

There are a plurality of mating die members A, B, C,

die member of each pair of die members.

The lower and stationary die members of the respective pairs of die members have been indicated by the reference characters A-2, B2, C2, D-2, E-2, F-2 and G-2. These stationary die members are rigidly supported in position and carried by the bedplate 23 by means of suitable brackets connecting the bedplate 23 with the of die members have been indicated by the reference characters A-l, B-l, C-l, D-l, E-1, F-l and G-1.

These upper die members are rigidly carried by means of suitable brackets to the reciprocating beam 24, so

that as the beam 24 moves up and down, the upper die The mating die members are spaced 34 passes through a guide member 41 which slidably receives the strip 35' and guides it in a longitudinaldirection so as to pass between the several pairs of die members.

A feed mechanism 31 iscarried by the beam "24 and ispo'sitioned' between pairs of di'emembers A and B inamanner to' engage the strip 35. The feedmechanism is adapted to advance the strip 35 in increments, upon each reciprocal movement of-the'beam 24; in a'manner to advance-the strip 35"toward the'r ight in'the apparatus in intermittent and-successive stages; In other words, the feed mechanism 31 advances the strip--35 through the apparatus step-by-step in accordance with the reciprocatingmovement of the upper die memberscarried by the beam 24.

Adjacent the right-hand end of the apparatus, there is acut-off device 32 which is actuated by a limit'switch so as to cut off a predetermined lengths of the strip after it has been completely formed bythe series of pairs of die members and as -it--leaves the last pair of die members G. A cut-off blade carried by the reciprocating upper die member 64 is adapted to cut off the strip on the rearward side of the die members G upon actuation of the cut-01f device 32 when the protruding strip encouters the limit switch of the cutoff device 32. By adjusting the cut-off device 32, pieces of the strip in the desired cross-sectional conformation and of the preselected length are cut off after being formed. These cut off lengths of. the. formed strip then drop down into a suitable receptacle.

The opposed mating. die. members have opposed surfaces which are directed toward each other in a manner to. engage the strip 35 as it passes between the opposed die members. The opposed surface of the upper die member is identified by the reference character 42 and the opposed surface of the lower die member is identified by thereference character 43. In the case of all of the die-members of the series of die members, the

opposed surfaces

42 and 43 are parallel to each other and are normal to the plane in which the opposed die members are disposed. and 43 of the several pairs of die members and which engage and press therebetween the strip 35 are at right angles to the plane of the reciprocating movement of the upper die members. All components of force resulting from the reciprocation of the upper die members relative to thelower die members and the strip engaging the

opposed surfaces

42 and 43 are maintained within the plane of the reciprocating movement. In other words, there is no component of force between the opposed die members which tends to thrust one of the die members forwardly or rearwardly relative to the otherdie members. The disposition of the

opposed surfaces

42 and 43 assist in maintaining all components of forcewithin the plane of opposed die members, this plane. being disposed transversely of the apparatus.

Each of the pairs of die members in the series hasa different contour or shape on the opposed surfaces'42 and 43 of the respective pairs of die members. The contour of die members A is relatively simple and forms but a slight bend in the strip 35. Each of the succeeding pairsof die members, reading from left to right in Figure 1, provides an additional bend or change in the form of the strip. These changes in form progress from the initial and simple fiat form of the strip as it enters the apparatus to a desired cross-sectional conformation as it leaves the apparatus. In the particular embodiment illustrated, the contour or form of the opposed surfaces 42 and 43 of the plurality of mating die members A to G, inclusive, are best illustrated by viewing the crosssectional conformation of the strip 35 at the location of each of the pairs of die members. The form of strip within the apparatus and showing the progressive changes in its form is illustrated in Figure 2. The cross-sectional conformation of the strip at various locations In other words, the opposed surfaces. 42

along the course of the strip through the apparatus is seen in Figures 3 to 10, inclusive. the strip 35 in its substantially flat form and as seen looking in the direction of the arrows 33 of Figure 2.

At the location of the opposed die members A, where the first forming is done, the strip is bent to have the conformation indicated by the reference character 35a and is illustrated in Figure 4.

' At the location of opposed die members B and between the opposedsurfaces therof, the strip 35 assumes the shape indicated by the reference character 35b and is illustrated in Figure 5.

At the location of the die members C and between the opposed. surfaces thereof, the strip has a cross-sectional conformation indicated by the reference character 35c and is illustrated in Figure 6.

At the location of the opposed die members D, the strip acquires the cross-sectional conformation indicated by'th'e reference character 35d and is illustrated in Figure 7.

At the location of the opposed die members E, the strip acquires the conformation indicated by the reference character 35e and is illustrated in Figure 8.

At the location of the .opposed die members F, the strip acquires the cross-sectional conformation indicated by the reference character 35f and is illustrated in Figure 9.

At the location of the opposed die members G, the strip acquires the conformation indicated by the reference character 35g' and is illustrated by the Figure 10.

Theshapes or contours of the opposed surfaces 42' and 43 of-the respective pairs of die members complement the shapes of the strip illustrated in Figures 4 to 10, inclusive. Inotherwords, the shapes or contours of the pairs of diemembers are arranged in a sequence which Inasmuch as the preceding form of the strip is different from the space between opposed surfaces42 and 43 of each following pair of die members, it is apparent that the strip as it approaches each of the pairs of die members is .out of phase with the shape or contour of the particular pair of die members that it is approaching. To accommodate the die members so as to readily receive. the strip in its preceding conformation and at the same time to maintain the desired disposition of the 0pposed surfaces 42 and 43, there are provided camming guide surfaces 36 and 37 upon the several pairs of die members. The camming guide surface on the upper and movable die members is denoted by the reference character. 36. The camming guide surface on the lower or stationary die members is indicated by the reference character 37. The guide surfaces are adapted to gradually funnel and bend the strip 35 from its preceding conformation so as to readily enter the space between the

opposed surfaces

42 and 43 of each pair of die members.

It is seen that the strip 35 in 'its flat form as it approaches the first die members .A does .not fully complement the shape or contour of the opposed surfaces 42 and 43- althoughasindicated it is preferable to have all of the- Figure 3 illustrates pairs of die members so constructed as to provide this described camming and guiding function. As noted in Figures 12 and 13, the camming guide surfaces 36 and 37 extend in a parabolic curve forwardly from the opposed surfaces 42 and 43, respectively, toward the forward face of the die members which is directed toward the preceding pair of die members; that is, toward the side from which the strip approaches the pair of die members. In some arrangements, the camming guide surface may be omitted from one of the die members of each pair of die members. For example, in the making of a V-shaped longitudinal member from a flat strip, the lower die member only may have the camming guide surface provided on it as this die member meets the strip in its preceding flatter form. Because not as necessary in such a situation, the camming guide surface could be eliminated or be more limited in extent on the upper die member. However, usually it is desirable to have the camming guide surfaces provided on both the die members of each pair of die members.

In Figure 11, the shape or contour of the opposed die members G1 and 6-2 is illustrated. As seen, this shape or conformation of the opposed surfaces 42 and 43 of die members G-1 and G-2 is arranged to provide the conformation 35g to the strip, that is, the form illustrated in Figure 10.

The feed mechanism 31 is so constructed and arranged as to feed the strip 35 forwardly through the apparatus in successive increments. These successive increments are in general governed by the effective length of the opposed surfaces 42 and 43 which press and form the sheet metal therebetween. By having the metal fed in increments which are substantially equal to or less than.

the effective length of the opposed surfaces 42 and 43 of the respective pairs of die members, it is assured that the whole length of the strip 35 is eventually and successively pressed and formed by

opposed surfaces

42 and 43 of each of the several pairs of die members. The step-by-step feeding of the strip in desired increments is obtained by the adjustment of the feed mechanism 31 which advances the strip 35 in the predetermined increment upon each stroke of the reciprocating beam 24 and upper die members carried thereby.

Of course, various modified constructions can be utilized in the adaptation of my apparatus and method for forming strip into different desired cross-sectional conformations. One of the modifications of the apparatus and one of the several ways in which the invention may be utilized is illustrated in Figure 14. In Figure 14, the lower die member is denoted by the reference character H-2 and the reciprocating die member is denoted by the reference character H-ll. A strip in the conformation indicated by the reference character 3542 has blind arches or open spaces therein usually not accessible by opposed die members. One of the ways to form a strip in the conformation 35-h is by utilizing a floating mandrel 38, which is held in alignment by a suitable socket in the upper die member H-ll. This mandrel 38 floats freely with the strip so as to be maintained within the partially closed pocket formed by the bending of the strip into the conformation 35-11. As the strip leaves the apparatus, it extends beyond the mandrel 38 and at the same time additional strip is fed to a position between the die members H-1 and H-2 and to be formed around the floating mandrel 38.

Another modification in the use of the invention is illustrated in Figure 15. Here the lower die member is indicated by the reference character J2 and the upper or reciprocating die member is indicated by the reference character JIl. In this modification, the upper die member Jl has a tongue portion 39 which protrudes downwardly between the throat or open space provided between the in-turned sides of the strip in the conformation indicated by the reference character 35 The tongue 39 moves downwardly to form the bottom corner of the through the open top of the strip in the conformation 35-j. This arrangement leaves the blind arches or open.

spaces 40 within the strip of conformation 35-j on each lateral side of the tongue 39. This illustrates another manner of forming the strip into desired. conformation, including conformations having blind or otherwise inaccessible interior portions.

The apparatus and method also lends itself readily to other variations and adaptations for the forming of sheet metal strip into desired conformation. It is readily seen that strip sheet metal may be efficiently and economically formed without the need of expensive mating rollers and without a large massive die. The same apparatus may be utilized for forming a strip of fiat sheet metal into other desired conformations by merely substituting other pairs of die members for the pairs of die members A to G, inclusive. The die mmebers are easily and cheaply made and may be produced in a much shorter period of time than is necessary for the fabrication of mating rollers and for the fabrication of massive and complex dies.

The invention is particularly useful when a relatively short run is to be made in forming strip sheet metal into desired cross-sectional conformation.

The present disclosure includes that contained in the appended claims, as well as that of the foregoing description.

Although this invention has been described in its pre ferred form and preferred practice with a certain degree of particularity, it is understood that the present disclosure of the preferred form and preferred practice has been made only by way of example and that numerous changes in. the details of construction and the combina tion and arrangement of parts and steps may be resorted to Without departing from the spirit and scope of the invention as hereinafter claimed.

What is claimed is:

1. Apparatus comprising the combination of a plurality of serially spaced die devices having opposed mating surfaces of sequentially varying contours progressing from simple to more complex shape for simultaneously pressing a strip of sheet metal therebetween at spaced intervals along the strip in formed increments having cross-sectional shapes at each of said intervals in correspondence with the said contours of the respective die devices, the opposed mating surfaces of each of the die devices being spaced from the opposed mating surfaces of next adjacent die devices to free the strip from compression intermediate of said spaced intervals, actuating means to simultaneously actuate all of said die devices in successive pressing operations to press a said increment of said strip by each of said die devices in each pressing operation, the strip free of compression intermediate of the opposed mating surfaces of next adjacent die devices gradually conforming lengthwise of the strip from the cross-sectional shape pressed at each interval to the crosssectional shape pressed at the next succeeding interval, and advancing means for simultaneously advancing the strip sequentially through said die devices during the interim between said successive pressing operations in successive increments corresponding to the formed incremen ts pressed by the respective die devices.

2. Apparatus as claimed in claim 1 and in which the opposed mating surfaces of each die device are so disposed relative to the plane of movement of the die device that the component of force exerted by the said opposed mating surfaces in opposition to each other in said pressing operations is maintained in said plane.

3. Apparatus as claimed in claim 1 and in which the opposed mating surfaces of each die device are disposed normal to the plane of movement of the die device and disposed parallel to each other.

4. Apparatus as claimed in claim 1 and in which each die device following the first die device in said series of die devices has a forward face directed toward the preceding die device andan inwardly sloping wall extending from'said forward face toward the opposed mating surfaces of the respective die device to provide a camming guide surface for said metal strip in being advanced to between the opposed mating surfaces of the respective die device.

5. Apparatus comprising the combination of, a plurality of serially arranged die sets spaced at intervals along a course, said die sets each having mating die surfaces of progressively varying contour from simple to more complex form, operating means for successively operating all of said die sets in unison to simultaneously press at all said intervals a strip of metal extending along said course through said die sets, the mating die surfaces of the successive die sets progressively bending said strip therebetween at said intervals into progressively varied cross-sectional forms corresponding to the said contours of the mating die surfaces and in formed increments determined by the extent lengthwise of said course'of said mating die surfaces of the respective die sets, the mating die surfaces ofeach successive die set being spaced lengthwise of said course from the corresponding die surfaces of the preceding die set a distance that is greater than the extent lengthwise of said course of the mating die surfaces of said each successive die set whereby the said strip may flex lengthwise of the course free of compression intermediate of said intervals during the bending of the strip into said progressively varied cross-sectional forms by successive die sets, and feed means synchronized With said operating means for advancing said strip in successive increments between successive pressing operations of the die sets.

6. Apparatus as claimed in claim and in which the mating die surfaces of each of said die sets are so disposed in respect to each other and in respect to the plane of relative movement between the mating die surfaces as to maintain within said plane the components of force produced by pressing of said strip between said mating die surfaces whereby thrust lengthwise of the course of one of the mating die surfaces relative to the other is minimized.

7. Apparatus as claimed in claim 5 and in which the mating die surfaces of each die set are disposed lengthwise of said course at right angles to the plane of relative movement between the mating die surfaces of the respective die sets.

8. Apparatus as claimed in claim 5 and in which each of thedie sets successively following the first die set of the series has a camming guide surface directed toward the preceding die set for meeting the strip as it is advanced by said feed means between successive pressing operations and guiding the strip from the preceding die set to between the mating die surfaces of the succeeding die set.

9. In combination, a plurality of sequentially arranged die devices positioned at spaced intervals along a course for pressing between the opposed mating die surfaces of the die devices a strip of metal progressing through the course into a series of cross-sectional forms having progressively increasing bends, operating means for simultaneously operating all said die devices to simultaneously press said strip at all of said intervals, said die devices being spaced apart a greater distance than the effective length of the mating die surfaces of the respective die devices to permit the strip to progressively conform lengthwise of the course without compression betweenthe die devices to the cross-sectional form being pressed at a said die device from the cross-sectional for-m being pressed at a preceding die device, and advancing means for advancing said strip in successive incrementsalong the course during the interim between pressing operations of said die devices to successively subject said increments to pressing by said sequentially arranged die devices.

10. The combination claimed in claim 9 and in which the die devices sequentially following the initial die device of the plurality of die devices are provided with a sloping wall surface adapted to meet and guide the strip during its advancement between pressing operations from the preceding die device to between the opposed mating die surfaces of the following die device.

11. The method of producing a metal body of desired cross-sectional bent form from a sheet-metal strip, comprising the steps of simultaneously pressing said strip at a plurality of spaced intervals in a series along the strip into a plurality of formed increments spaced apart longitudinally of the strip and having cross-sectional bent forms progressively varying in degrees of bent contour from simple form to said desired cross-sectional bent form; permitting said strip intermediate of said spaced intervals to flex free of compression during said simultaneous pressing of the strip at said intervals to allow the strip to progressively accommodate itself to the differences in cross-sectional form at said intervals; releasing said strip from said pressing operation; advancing said-strip while released an increment corresponding to said formed increment along said series of intervals; and consecutively repeating the described steps of pressing, permitting u to flex, releasing and advancing of said strip to progressively produce the metal body of desired cross-sectional form from said strip.

12. The method as claimed in claim 11 and in which the metal strip while released and being advanced a said increment is cammingly guided toward a succeeding interval in the cross-sectional bent form provided at a preceding interval from a location spaced from said preceding interval and immediately preceding the next succeeding interval.

13. The method as claimed in claim 11 and in which the components of force produced in said pressing of the strip are maintained in the planes of the respective pressing movements to avoid working of the metal strip lengthwise of the strip by said pressing.

References (Iited in the file of this patent UNITED STATES PATENTS 477,536 Guerber June 21, 1892 684,865 Richard Oct. 22, 1901 846,139 Pruden Mar. 5, 1907 1,634,562 Shapiro July 5, 1927 1,708,872 Coates Apr. 9, 1929 1,909,930 De Ridder May 23, 1933 2,295,131 Scott Sept. 8, 1942 2,405,738 Dettman Aug. 13, 1946 FOREIGN PATENTS 435,722 Great Britain Sept. 26, 1935