US2954066A - Means for supporting and guiding sheets in sheet forming machines operating on forming-by-drawing principle - Google Patents

Description

D GUIDING SHEETS IN SHEET F0 pt 1950 F. ANDERSON MEANS FOR SUPPORTING AN RMING MACHINES OPERATING ON FORMING-BY-DRAWING PRINCIPLE Original Filed Feb. 8, 1955 5 Sheets-Sheet l Sept. 27, 1960 F. ANDERSON 2,954,066

MEANS FOR SUPPORTING AND GUIDING SHEETS IN SHEET FORMING v MACHINES OPERATING ON FORMING-BY-DRAWING PRINCIPLE Original Filed Feb. 8, 1955 5 Sheets-Sheet 2 F. ANDERSON 2,954,066

GUIDING SHEETS IN SHEET FORMING FORMING-BY-DRAWING PRINCIPLE 5 Sheets-Sheet 4 Sept. 27, 1960 MEANS FOR SUPPORTING AND MACHINES OPERATING ON Original Filed Feb. 8, 1955 ii JQQv 1 MA lll' llli llllllll I I'll' I I I I I l I l I. "H H l Inn" Ill IIIIII'QII I I l I I I I I I ll 2,954,066 ORMING Sept. 27, 1960 D N MEANS FOR SUPPORTING AND GUIDING SHEETS IN SHEET F MACHINES OPERATING 0N FORMING-BY-DRAWING PRINCIPLE Original Filed Feb. 8, 1955 5 Sheets-Sheet 5 MEANS FUR SUPPORTING AND GUIDING SHEETS IN SHEET FURMING MACHINES OPERATING ON FORMING-BY-DRAWING PRHNCHPLE Frohman Anderson, 3320 S. th St., Las Vegas, Nev.

Griginal application Feb. 8, 1955, Ser. No. 486,773, now Patent No. 2,851,080. Divided and this application Dec. 13, 1957, Ser. No. 702,641

14 Claims. (Cl. 153-32) This application is a division of application Serial No. 486,773, filed February 8, 1955, now Patent No. 2,851,080, which relates to a machine for shaping metal sheets into compound curves by pulling the sheets edgewise from one end to the other over a series of forming elements the working faces of which differ in contour transversely of the sheets and are disposed instepped relation, a restraining or hold-back force being'exerted on the sheets in opposition to the pulling force to subject the sheets to a stress beyond their yield point. This operation in the parent case is termed forming-by-drawing.

1n the forming passage of the sheet through the machine there are three stages of operation. The hold-back force is applied at the first stage which determines the general path of movement of the sheet, and the second and third stages have each a draw-over forming element disposed so as to cause the sheet to be engaged on its reverse sides as it passes over them.

At the first stage which constitutes the hold-back stage, opposing elements define a slot of variable opening through which the sheet is drawn and Within which the restraint is applied. It is to the means for supporting the sheet to facilitate its location into exact initial position, and for guiding it during the draw that the present invention relates. a

The draw mechanism includes jaws which are brought up into proximity with the third stage to grip the-leading edge of the sheet and then are reversed to pull the sheet over the forming elements in the'forming section of the machine. A sheet is fed by hand into this gripping position and as initially positioned it is flat, the first and second stage elements being so disposed at the time of sheet feed as to permit the sheet to remain flatv Thereupon the first and second stage elements are moved into operative position in which they are in stepped relation and the leading edge of the sheet is brought into register with the jaws.

Commonly, the sheets are fed into the machine by hand and it is essential that tney be properly laterally as well as longitudinally positioned, and that the forward movement of the sheets to bring them into position be facilitated. To this end, the invention contemplates side longitudinally extending bars immediately back of the elements of the first or hold-back stage which are spaced to receive the edges of the sheet and are provided with iantifriction rollers upon which the edges of the sheet rest and with guide rollers which contact and guide the edges of the sheet. In addition antifriction means are provided in the space between the side bars, mounted upon structural parts of the machine, which support the intermediate portion of the sheet in the plane of its edges.

In order to accommodate the side bars to different widths of sheets, the bars in accordance with the invention are laterally adjustable toward and from each other.

If the sheets are rectangular, that is, if both sides meet the leading edge in a right angle, then the two side bars are parallel and in proper spaced relation for the guide rollers to engage the side edges of the sheet throughout the draw. When, however, the sheets are other than rectangular, as is the case when one or both of the side edges meet the leading edge at other than a right angle, then the side bars must be correspondingly positioned in order properly to frame the sheet in its initial position and give it its proper lateral disposition relative to the forming elements. Since the wider transverse edge of the sheet must obviously lead, it follows that a tapering longitudinal edge will leave its guide rollers as the sheet is pulled by the jaws and that portion of the sheet will come to rest entirely upon the interior antifriction supports.

The invention, therefore, contemplates a mounting for the side bars which is capable of angular as well as transverse adjustment. The invention also comprehends other objects andadvantages as will appear from the following description of the embodiment of the invention illustrated in the accompanying drawings.

Fig. 1 is a side elevation of a complete machine embodying the invention.

Fig. 2 is a plan of the same.

\Fig. 3 is ,a vertical section of the machine on a longitudinal plane central of the forming structure.

Fig. 4 is a plan of the sheet supporting and guiding structure, with a sheet shown in place but partially broken away. I

Fig. 5 is a vertical section taken on the line 55 of Fig. 4. Fig. 6 is a fragmentary enlarged section taken on line 6-6 of Fig. 5.

Fig. 7 is a fragmentary plan on reduced scale showing one of the sheet supporting guides in adjusted position.

Fig. 8 is a fragmentary section taken on line 88 of Fig. 7.

The forming elements for the three stages are contained between two uprights 1i) and 1.1 which are attached to and supported upon a sub base 12;. A draw bench which comprises a stationary channel guide 13 and a carriage 14 slidable therein, is disposed immediately outside the upright 10 and is supported upon a gear box 15 which rests upon the sub base 12. Upon the sub base 12 is a main base 16 disposed within the uprights 1i and 11 which, among other functions, provides a guide for a rearwardly extending leg of the third stage structure and supports a guide structure 17 upon a gimbal support 18. This guide structure 17 provides a guide support for a rearwardly extending leg of the lower portion of the first stage structure.

The gearing in the gear box 15 is driven by a motor 19 supported upon the sub base 12, through a gear reduction in the housing 20 and a coupling 21. The gearing includes a bull gear 22 which engages a rack on the underside of the carriage 14 and actuates the rack in its channel guide. Attached to the carriage and moved thereby is the pulling mechanism for pulling the sheets through the forming stages, including an arm 23 which extends in front of the forming elements, and a draw head 24 having jaws 25 which grip the leading edge of the sheet, as indicated by broken lines in Fig. l. v

The first stage structure comprises a lower portion and an upper portion. The lower portion has a T-shape body member 26 the cross head of which extends berial to this invention.

The upper portion of the first stage structure includes a transverse bar 29 which constitutes a ram that is Pa tented Sept. 27, 1960 raised and lowered through a hydraulic motor 29a and toggles as appears in Fig. 3, and has a hold-back element 30 in opposition to thelower element 27.

The second stage forming element 31 is disposed in front of the first stage and in vertical opposition to the third stage forming element 32. The second stage forming element 31 is carried by a transverse bar 33 that extends between the uprights and 11 and is raised and lowered through a hydraulic motor 34 (Fig. 2). The third stage forming element 32 is carried by the cross head of a T-shape body member 35, the leg 36 of which extends rearwardly underneath leg 28 in a channel shape guide in the main base 16. The third stage body member is longitudinally adjustable by a hydraulic motor 37 for a functional reason in the forming of the sheets not here material.

The body member 26 of the first stage lower portion is moved back and forth in its channel in the guide structure 17 by a hydraulic motor 38 operating through a crank 39, the pivot shaft 40 of which bears in hubs 40a on side plates 41 which are attached to and extend rearwardly from the guide structure 17. The motor 38 is mounted in a trunnion ring the trunnions of which also hear in hubs on plates 41.

The crank 39 is connected to the rear end of leg 28 by a pair of link bars 42 which are connected to the crank at their rear end by pivot 43 and to the leg 28 at their front end by pivot 44.

The channel in guide structure 17 in which leg 28 is guided is partially covered at the top by plates 45, 46 and 47. These plates are on substantially the level of the top faces of the linkbars 42 and together they form a center line portion of a supporting table for the blank or unformed sheets as they are fed into the machine. As will be pointed out, antifriction rollers or the like are provided on this center portion of the table to facilitate the moving of the sheets to their proper initial position.

To support the edges of the sheets side bars are provided on the level of plates 45, 46 and 47 and of the link bars 42. Thus there is provided a feed table which overlies the guide structure and main base and parts carried by them behind the uprights 10 and 11 and the forming elements within these uprights.

The side bars are inverted channel bars mounted upon transverse guide plates on which they are adjustable to the width of the sheet. Also provision is made for angular adjustment of the bars for sheets having one or both sides at an angle other than a right angle to the leading edge of the sheet.

In the construction shown the channel side bars are in two sections, there being the longer bars 48 and 49 in the rear on the left and right sides, respectively, and shorter channel bars 50 and 51, respectively, in front. The bars 48 and 49 are slidably mounted at their rear ends on a transverse plate 52 which is supported on the upper ends of legs 53 attached at their lower ends to the hubs 40a of pivot shaft 40. At their front ends, the bars 48 and 49 are slidably mounted on relatively short transverse plates 54 and 55, respectively, the inner ends of which plates extend into proximity to the opposite sides of links 42. Intermediate their ends, these short guide plates 54 and 55 are attached to plates 41 near the attachment of these plates to the outer faces of the guide structure 17. This attachment is by plates 56 and 57, respectively, to which the guide plates 54 and 55 are welded and which are bolted or otherwise secured to the respective trunnion bearing plates 41.

The short front sections 50 and 51 of the side channel bars are also supported and guided for lateral adjustment by transverse plates 58 and 59 for bar 50 and similar plates 60 and 61 for bar 51. The plate 58 is attached near its inner end to one side of the guide structure 17 by plate 62 to which it is welded, and similarly the inner end of guide plate 6.0. is attached to the other side of the guide structure 17 by plate 63. The guide plates 59 and 61 are secured at their inner ends to an upright member of guide structure 17, .as by bolting.

The guide plate construction for the longer side bar sections 48 and 49 is braced by rods 64 and 65 which are secured at their rear ends to plate 52 and at their front ends to plates 54 and 55, respectively.

The details of the guide connections between the side bars and their transverse plates are shown particularly in Figs. 6, 7 and 8. Each plate has a longitudinal g-uide groove on one face near its top and in the channel of each side bar is disposed clamping means. For reasons which will appear, the clamping means for the bars at their rear ends differ from those at their front ends, but both include a block secured in the channel and a clamp that has a tongue engaging in the groove of the guide plate and a screw which passes loosely through the clamp and screws into the block so that setting up on the screw will clamp the bar to the guide plate.

As stated above, it may be desirable to set the side bars on one or both sides at an angle to the longitudinal axis of the machine. For this reason, the block in the rear end of each bar is adjustable longitudinally of the bar while the block in the front end of each bar is fixed.

The clamp construction in the rear end of the bars as shown in Figs. 6, 7 and 8, has an adjustable clamp block 66 which has a tongue engaging in the longitudinal groove in the guide plate and cooperates with an opposing block 67 through a clamp screw 68. The block 67 is T-shape with its head riding upon two strips constituting guide rails 69 spaced to form a guide slot between them, with their ends welded upon cross members 70 spanning and welded upon the bottom edges of the flanges of the side bar. The leg of the block 67 is slidably disposed in the slot between the guide rails 69. On the side of the guide plate opposite the clamp block and screw, the block 67 has a depending pin 71 which cooperates with the clamp block 66 and screw 68 to maintain the block 67 in a definite relationship to the guide plate, a certain looseness being tolerated in this relationship. Thus the clamping means for each side bar includes a member, the clamp block 66, and respectively cooperating members, the blocks 67, which engage one of the guide plates, each clamp block and cooperative block being connected by a headed clamp screw 68 which has its axis normal to the side bar.

The clamp arrangement above described is the same for the rear ends of all four side bar sections in that the block 67 is slidable on rails 69. The clamp construction for the front ends of all four sections are all alike but differ from those in the rear end in that the opposing block 72, which corresponds to the block 67, is welded permanently in place and is immovable. It has a depending pin 71 on one side of the guide plate and the tongue of clamp block 66 engages in the groove on the opposite side of the plate.

In the arrangement shown, the clamps for the longer sections 48 and 49 are reversed relative to those for the shorter sections 50 and 51, in that for the longer sections the pins 71 oppose the inner faces of the guide plates, while for the shorter sections the pins 71 oppose the outer faces of the guide plates. This is primarily for convenience of access to the clamp screws and is without func tional purpose.

In order to place a sheet in position on the table, the upper portion of the first stage structure, and the second stage structure are raised, and the sheet S is laid on the table in a position for its front edge to be engaged by the jaws 25 as shown in Fig. 1. The side bars have antifriction devices consisting of horizontal supporting rollers 73 on both sides of the bars and proximate thereto, and also on their outer side rollers 74 on vertical axes to engage and guide the edges of the sheet. Also horizontal rollers 73 are provided on the links 42 and on the top edges of the guide walls for the leg 28 in guide structure 17. In addition, antifriction balls 75 are provided on the top plates 45, 46 and 47. These antifriction rollers and balls are in a common sheet contacting plane and the sheet when laid thereon is flat and can be easily moved into position.

When the clamp screws 68 are loosened, the side bars can be moved along the grooves in the guide plates. If the sheet has parallel sides perpendicular to the front edge, the bars are moved laterally in parallel relation to the Width of the sheet so that the edges of the sheet engage the rollers 74, whereupon the clamps are again tightened.

If the blank is not rectangular and it is necessary to place the bars on one or both sides at an angle, this is done in a manner illustrated in Fig. 7. The bar may be pivoted about the axis of screw 68 at either end, and one end, of course, being caused to move along its guide plate.

Fig. 7 shows a position of bar 48, for example, when set at an angle by pivoting about the front end. In this case, the clamps are released on both ends so that the bar can freely pivot about the front end and can pivot and slide at the rear end between the rails 69.

To prevent the side bar with its'rollers and clamping parts from accidentally escaping off the end of the guide plate, a latch 76 is provided on the ends of the plates. This latch is pivoted on the outer end of each plate and is long enough to extend above the top of the plate when in latch position in front of the clamp 66.

While the guide plate 52 is the only one which is' integral from side to side, the other three guide plates being interrupted at the center, there are in effect four guide plates constituting two pairs in succession longitudinally of the machine, the rear pair supporting and guiding the longer pair of side bars and the front pair supporting and guiding the shorter pair of side bars.

It will be understood that the construction of feed table shown in the drawings and above particularly described is representative only of embodiments of the invention possible within the scope of the invention as defined in the following claims.

What is claimed is:

1. In a forming-by-drawing machine having a first stage hold-back structure forming a slot through which a work sheet is drawn, means to support and guide a work sheet into the slot comprising two transverse guide plates fixed on the machine, a pair of horizontal side bars supported upon and having slide engagement with the guide plates to permit their movement toward and from each other, means to releasably clamp the bars to the plates in laterally adjusted position, said clamping means including a member carried by each bar and respectively cooperating members engaging one of the guide plates, a headed clamp screw connecting each bar carried member and its respective cooperating member and having its axis normal to the bar and constituting a pivot axis for the bar, a pin parallel to the screw axis carried by each bar carried member on the side of the guide plate opposite the respective clamp screw, anti-friction supporting rollers on the bars mounted on transverse axes immediately adjacent the inner faces of the bars with their peripheries extending slightly above the top faces of the bars, and anti-friction side guide rollers on the bars, said side guide rollers being disposed above the top faces of the bars and mounted on vertical axes outside the supporting rollers.

2. The mechanism defined in claim 1 in which the cooperating member is a clamp block having a tongue slidably engaged in a longitudinal groove in the guide plate and the respective member carried by each side bar is an opposing block having a threaded bore therein, and the headed clamp screw passes loosely through the clamp block and screws into the threaded bore in the opposing block and is adapted to bind the tongue of the clamp block to the guide plate in the said groove.

3. The mechanism defined in claim 2 in which the side bar at one end is provided with a longitudinal. slot and the opposing blockis headed and is slidably disposed in said slot.

4. The mechanisrndefined in claim 3 in which the opposing block has a pin dependingat the side of the plate opposite the clamp screw and in proximity to said side and cooperating with the clamp block to limit longitudinal movement of the .bar relative to the guide plate.

5. In a forming-by-drawing machine having a first stage hold-back structure including an upper portion and a lower portion cooperating to form a slot through which a work sheet is drawn, means to support and guide a work sheet into the slot comprising a support for the lower portion, a rearwardly. extending leg on the lower portion, a pair of horizontal adjusting links attached to the rear end of said leg in the horizontal plane thereof, two transverse guide plates carried by said support, a pair of side bars on opposite sides of the said leg and links, said bars being supported-upon and having slide engagement with the guide plates to permit their movement toward and from each other, means to releasably clamp the bars to the plates in laterally adjusted position, antifriction supporing devices on the said leg and on the said links in a common supporting plane, and antifriction supporting devices on the side bars in said common supporting plane.

6. The mechanism defined in claim 5 in which the side bars are inverted channel members and the clamping means comprise a clamp block having a tongue slidably engaging in a longitudinal groove in one of said side plates, an opposing block disposed in the channel of one of said side bars and having a threaded bore therein, and a clamp screw passing loosely through the clamp block and screwing into said bore.

7. The mechanism defined in claim 6 in which the opposing block at one end of the side bar is supported in the channel with freedom of sliding movement longitudinally of the bar.

8. The mechanism defined in claim 7 in which the bar is provided at the said one end with a pair of guide rails secured longitudinally in the channel and defining a slot between them, and the opposing block is T-shape with its head engaging the inner face of the rails and its leg in the slot and having the threaded bore therein.

9. The mechanism defined in claim 7 in which the opposing block has a pin depending at the side of the plate opposite the clamp screw and in proximity to said side and cooperating with the clamp block to limit longitudinal c movement of the bar relative to the guide plate.

10. In a forming-by-drawing machine having a first stage hold-back structure including an upper portion and a lower portion cooperating to form a slot through which a work sheet is drawn, means to support and guide a work sheet into the slot comprising a support for the lower portion, two pairs of parallel transverse guide plates carried by said support and disposed in succession at the rear of said slot, a pair of side bars supported upon and having slide engagement with each pair of guide plates to permit their movement toward and from each other, and means to releasably clamp the bars to their respective guide plates in laterallyadjusted position, said clamping means including a member carried by each bar and a member engaging one of the guide plates and a headed clamp screw connecting the two members with its axis normal to the bar and constituting a pivot axis for the bar.

11. In a forming-by-drawing machine having a first stage hold-back structure including an upper portion and a lower portion cooperating to form a slot through which a work sheet is drawn, means to support and guide a work sheet into the slot comprising a support for the lower portion, two pairs of parallel transverse guide plates carried by said support and disposed in succession at the rear of said slot, a pair of inverted channel shape side bars supported upon and having slide engagement with each pair of guides plates to permit their movement toward and from each other, and means to releasably clamp the bars to their respective guide plates in laterally adjusted position, said clamping means including for each side bar a clamp block having'a tongue slidably engaged in a longitudinal groove in the side plate, an opposing block carried by the bar and having a threaded bore therein, and a headed clamp screw passing loosely through the clamp block and screwing into the threaded bore in the opposing block. V

12. The mechanism defined in claim 11 in which each side bar at one end has fixed thereto a longitudinally slotted support for the opposing block with the block disposed and movable in the slot. p

.13. The mechanism defined in claim 12 in which in each side bar the opposing block in the other end is at tached to and immovably fi'x'ed in the channel.

14. The mechanism defined in claim 12 in which each opposing block has a pin depending at the side of the guide plate opposite the clamp screw in proximity to said plate and cooperating with the clamp block to limit the longitudinal movement of the side bar relative to the guide plate.

References Cited in the file of this patent UNITED STATES PATENTS 142,754 Wood sept. 9, 1873 392,132 Patrick Oct. 30, 1888 844,549 Spangler Feb. 19, 1907 903,594 Maddrell Nov. 10, 1908 1,673,787 Frahm June 12, 1928 1,815,578 OBrien July 21, 1931 2,072,121 Montgomery Mar. 2, 1937 2,394,824 Todd Feb. 12, 1946 2,480,826 Anderson Sept. 6, 1949 2,767,951 'Cousino Oct. 23, 1956 FOREIGN PATENTS 680,075 Great Britain Oct. 1, 1952

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