US2937686A - Bending machines - Google Patents

Description

May 24, 1960 B. GREEN szunmc MACHINES '7 Sheets-Sheet 1 INVENTOR. EE 8. GREEN v I i I Arm/avers MW m,

Filed June 10, 1958 L. B. GREEN May 24, 1960 NDING MACHINES 7 Sheets-Sheet 3 Filed June 10, 1958 m hk r///////////Vv/////////////////////////////////////flflfl mm m. w B s a ,4rra NEYS May 24, 1960 L. B. GREEN BENDING MACHINES '7 Sheets-Sheet 4 Filed June 10, 1958 IN VENTOR. [as 3 GREEN ATTORNEYS W @y fi May 24, 1960 1.. B. GREEN SENDING MACHINES 7 Sheets-Sheet 6 Filed Juna 10, 1958 I N VE N TOR [6 15. GREEN I flrrcwA/em I i n WMW United States Patent BENDING MACHINES Lee :3. Green, 20280 Parklane Drive, Rocky River 16, Ohio Filed June 10, 1958, Ser. No. 741,154

17 Claims. (Cl. 153-46) This invention relates to metal bending machines and, more particularly, to bending machines of the kind having clamping dies for clamping a workpiece therebetween and a bending die rockable relative "tonne of the clamping dies for bending portionsof: the workpiece around the latter. "Machine's o'f'tliis kind have been particularly useful in carrying out bending operations on workpieces having web and flange portions by bending the web portion out of its own plane and by bending the flange portion or portions within their own planes, and have accomplished bending operations of this character in a highly satisfactory manner and substantially without buckling of the flange portions and usually Without need for notching of the flange portions.

When the bend to be made in such a workpiece is a relatively small-radius bend, the operation becomes more difficult because of the problem of taking care of the excess metal in the flange portion of the workpiece and the problem of appropriately controlling the movement of the rockable bending die. In previous bending -machines of this type the desired control of the rockable bending die has usually been achieved by the use of cooperating rack and gear members, as is exemplified in my earlier Patents 2,287,933 and 2,482,617, but when the radius of the bend to be made is small, it is not practical to employ such rack and gear members for controlling the bending die.

The present invention solves this problem and, as one of its objects, aims to provide a novel bending machine of the kind above referred to and wherein the bending die actuation is controlled by the use of eccentric pivot means.

Another object is to provide a novel bending machine having eccentric pivot means for controlling the movement of a bending die actuated by a swingable member and wherein adjusting means for varying the oifset relation or eccentricity of the pivot means renders the machine adaptable for making bends of various difierent radii.

Other objects and advantages of this invention will be apparent in the following detailed description and in the accompanying drawings forming a part of this specification and in which,

Fig. 1 is a plan view of a bending machine embodying this invention; I

Fig. 2 is a front elevation of the machine;

Fig. 3 is a vertical section taken through the machine on section line 3--3 of Figs. 1 and 2;

Fig. 4 is a partial side elevation of the front portion of the machine;

Fig. 5 is a perspective view partly in section showing the die-carrying portions of the machine;

Fig. 6 is a partial vertical section taken through the die-carrying portions of the machine as indicated by section line 6--6 of Figs. 1 and 5;

Fig; 7 is a partial vertical sectional view similar to that of Fig. 6 but more or less diagrammatic in form and 2,937,686 Pattented =May 24, 1960 'g'. "1'0 is a partial vertical section taken through the modified bending machine approximately as indicated by the section line 1010 of Fig. 9;

Fig. 11 is a sectional view taken through the bending die control means as indictaed by section line ll-11 of Fig. 10; Y t

Fig. 12 is a partial vertical section corresponding with a portion of Fig, 10 and showing another position of the bending die and bending die carrier;

Fig. 13 is a partial side elevation of a flanged workpiece to be bent; and

Fig. 14 is a partial side elevation of the workpiece after the bending operation thereon.

As one practical embodiment of the present'invention, the accompanying drawings show a bending machine 10 having a frame structure 11 and a group of cooperating die members 12, 13 and 14 for performing a bending operation on a metal workpiece 15.

he die members consist of a pair of co-operating'work clamping dies, here represented by the die members 12 and 13, for receiving the workpiece 15 therebetweenand of which the member 12 is a stationary die member and the member 13 is a movable die member which ismovable toward and away from the member '12 for clamp- The movable die meming or releasing the workpiece. ber 13 is also an anvil die for bending of the workpiece thereagainst or therearound, as is explained hereinafter. The :movable die member 14 is a bending die which is rockable relative to the anvil die 13 for causing the bending of the workpiece 15 against or around the latter.

The frame structure 11 comprises a stationary main frame member or base 17 having a transverse support portion or ledge 18 on which the die member 12 is mounted, and swingably movable second'and third frame members 19 and 20 which support and actuate the respective die members 13 and 14.

Before proceeding with a more detailed description of the machine 10, the character of the workpiece 15 and the bending operation to be performed thereon should be described. As representative of one formof workpiece to be bent by the machine 10, Figs. 13 and 14 show the workpiece 15 as comprising a sheet metal mem' her having a web portion 22 and parallel longitudinal edge flanges 23 extending along the edges thereof. Fig.

13 shows the workpiece 15 prior to the bending operation thereon. Fig. 14 shows the workpiece after being bent by the dies of the machine 10 and as having, for example, a small-radius bend 25 formed by such dies.

Because of the considerable amount of metal of the flanges 23 which must be taken care of for the successful performance of bending operations of this kind, particularly for such small-radius bending operations, the workpiece 15 can be prepared for the bending operation by cutting suitable notches 26 in the fianges.- The notches 26 extend for only a portion of the depth of the flanges and, as shown in Fig. 13, the portions 27 of the flanges which lie nearest the web portion 22 are left intact or unnotched. The notch 26 can be of a substantially right angle shape when the bend 25 to be made is a substantially right angle bend as shown in Fig. 14 and, in forming the notch, a portion of the flange is preferably left to extend into the notch recess as aj'ointforming edge or lip 28 for subsequent welding to the edge portion 29 at the opposite side of the notch.

During the formation of the bend 25 the web portion 22 is bent out of its own plane and the unnotched portions 27 of the flanges 23 are bent within the planes of the flanges. At the completion of the bend 25 the lips 28 of the flanges 23 will lie in an overlapping relation to the edge portions 29, as shown in Fig. 14. The overlapping lips 28 can be secured to the edge portions 29 by suit able welding operations, after which the lips 28 can, if desired, be removed as excess metal as by means of a suitable grinding operation to leave the side faces of the flanges 23 in a smooth and flush condition at the location of the bend 25.

Important advantages are realized from the use of the bending machine in producing workpieces, such as the workpiece 15, having the bend 25 therein. One of these advantages is that the unnotched portions 27 of the flanges 23 can be bent entirely within the planes of the flanges without buckling or wrinkling of these portions of the flanges. When these unnotched portions 27 are thus bent within the planes of the flanges 23, the need for notching the flanges for their full depth is avoided and the bent workpiece will be of a much more smooth and regular shape at the location of the bend, and will be much stronger and more rugged then if the bend had been made by the use of notches of the full depth of the flanges.

Moreover, when the unnotched portions 27 of the flanges 23 are bent by the machine 10 in the manner ex plained above, the need for performing any welding or grinding operations at or near the rounded apex 25 of the bend is avoided. To perform such welding and bending operations at, or closely adjacent to, the apex portion 25 as would be necessary if the notches 26 were of the full depth of the flanges 23, would be extremely diflicult and time consuming because of the problem of obtaining a smooth and regular finished curvature for the apex portion.

Reverting now to the detailed description of the bending machine 10, it will be observed that the main frame member or base 17 includes a bottom plate 32 on which the machine is adapted to stand or rest, an upright front wall 33, and a pair of upright side walls 34 and 35. The front wall 33 extends between and is connected to the side walls 34 and 35 adjacent the front end of the machine. An L-shaped connecting bar 36 extends between and is connected with the side walls adjacent the rear end of the machine and at an elevation above the bottom plate 32, as shown in Fig. 3. A longitudinal, channel-shaped support 37, comprising angle bars 37 and 37 extends longitudinally of the main frame member 17 and has its front end attached to the front wall 33 as by means of screws 38 and has its rear end attached to the transverse bar 36 as by means of suitable screws 39.

The swingably mounted frame member 19 is in the form of a yoke, as shown in Fig. 1, comprising a transverse front bar 41 and a pair of yoke arms 42 and 43 connected to the ends of the transverse bar and extending rearwardly of the main frame member 17 adjacent the side walls 34 and 35 of the latter. The frame member 19 is swingably mounted on the main frame member 17 by having the rear ends of its yoke arms 42 and 43 fulcrumed on the side walls 34 and 35 by means of pivot pins 45 and 46 carried by such side walls.

The transverse front bar 41 of the frame member 19 forms a mount on which the anvil die member 13 is located and to which this die member is secured as by means of suitable attaching bolts 47. The swinging movements of the frame member 19 are guided in the main frame member 17 as by means of guide screws 49 and 50 adjustably mounted in the side walls 34 and 35 and having guide elements 52 on the inner ends thereof which are in sliding engagement with guide pads 53 provided on the sides of the yoke arms 42 and 43.

The swingable frame member 19 is actuatable by suitable power means which is here shown as comprising a double-acting fluid pressure responsive cylinder device 54 and a transverse rock shaft 55. The rock shaft 55 has its opposite ends journalled in the side walls 34 and 35 by means of suitable support bearings 57 and 58 pro' vided on the latter and has a lower input lever 59 secured thereon at a point substantially longitudinally opposite an end of the cylinder device 54.

The rock shaft 55 has power output levers 60 and 61 secured thereon at points located just inwardly of the side walls 34 and 35 and which levers carry crank pins 62. The swingable end of the frame member 19 is connected with the levers 60 and 61 by upright links 63 and 64 for imparting raising and lowering swinging movements to this frame member in response to rotation of the rock shaft 55 in opposite directions. The links 63 and 64 have their lower ends pivotally connected to the levers 60 and 61 by the crank pins 62 of the latter and have their upper ends connected to the frame member 19 by pivot pins 65 carried by the yoke arms 42 and 43.

The actuating lever 59 for the rock shaft 55 is provided at the free end thereof with a crank pin 67 by which the outer end of the piston rod 68 of the cylinder device 54 is pivotally connected with this lever. The inner end of the piston rod 68 is connected with a suitable piston which is movable in the cylinder device 54 in response to pressure fluid being supplied to, and exhausted from, opposite ends of this device through suitable conduit connections 71 and 72. At the end thereof remote from the piston rod 68, the cylinder device 54 is connected with the longitudinal support 37 as by means of a suitable mounting bracket 73 attached to the latter and a suitable pivot pin 74.

The frame memberZi is a swingable frame member or wing having a transverse plate-like support portion 76 extending between and connected with a pair of parallel upright side walls '77. The wing 20 also includes an upright rear wall 78 having its upper transverse edge portion connected with the rear edge portion of the support portion 76, and also having its opposite ends connected with the upright side walls 77. The wing 28 also comprises a pair of yoke arms 80 and 81 by which the wing is swingably connected with the side walls 34 and 35 of the main frame member 17 and which arms have the side walls 77 of the wing attached thereto as by suitablescrews, or the like, 82.

The bending die 14 is actuated by the swinging movements of the wing 20, as will be further explained here inafter, although it is not mounted directly on the support portion 76 of the wing but on a die carrier or socalled slip plate" 83 which has translatory movement relative to the support portion. The side walls 77 of the wing have top edge portions 84 and 85 which extend above the support portion 76 and co-operate with the latter in defining a guideway 86 in which the carrier 83 is movable and is retained by retainer strips or gibs 87 secured to the edge portions 84 and 85 by screws 88 and overhanging the guideway. The carrier 83 is slidably supported in the guideway 86 by suitable bearing strips 89 provided on the support portion 76 of the wing.

As shown in Fig. 5, the stationary work supporting and clamping die member 12 is of a shape appropriate for supporting and clamping co-operation with the workpiece 15 and, in this instance, has a flat portion 16 against which the Web 22 is adapted to be clamped by the anvil die 13 and also has hardened L-shaped wear strips 21 whose upright flange portions 21 are adapted to overlap the side faces of the anvil die for confining the flanges 23 against the latter.

The anvil die 13 is of an appropriate shape for clamp ing the workpiece 15 against the die member 12 and has side faces 24 against which the flanges 23 are confined by the portions 21 of the latter die member. The anvil die 13 also has a curved portion, in this case, a curved ing the workpiece 15 around the anvil die. '83 has limited shifting movement in the guideway 86 ina direction normal to the plane of thesupport portion 76 to enable the bendingdie 14 to bepressed against ea-pawns priate for the workpiece 15 and the bendingoperation to .be performed on the latter, and is. mounted on the carrier 83 by suitable attaching bolts 90. The bending .die I14 .is hereshown ashaving a fiat .portion 92 :for pressing the .web 22 of the workpiece against the anvil die13 and alsohas hardened L-shape'diwearstrips 93similar to those of the die member 12. .The .strips '93 :have portions 693 which are adapted to overlap the sides 24 ofthe'anvil 'die for confining the flanges .23 :against such sides during 1 the bending operation.

During thebending operation performed by the bending die 14, this die memberis rocked against the anvil die 13 by-an upward swinging of the wing 20 for-bend The carrier the workpiece during the bending operation-by the action of compression springs' 94 provided in pockets 95 of the wing and-which springs are effective-against the underside of the carrier through bearing pads 96 slidably engaged by-the latter.

In preparation for the bending .operation, theflanged workpieceis inserted into the=machine in overlying relation to the bending die 14 and the-stationary die 12 is clamped against the latter by a downward closing movement imparted tothe anvil die 13 by the :swingableframe member 19. The initial position for the wing -2'0,'tl e carrier 83, and the bending 'die '14 is that shown in Figs. 3 and 6 of the drawings'in-which the carr ier 83 is located in front of and-aligned-with the supportportion 18 of the main frame member .17 and the die members 12 and 14 have their adjacent edges in cooperating engagement at a parting line- 91. V

The bending operation is carried out by the abovementioned rocking of the bending-die "14 againstthe anvil die 13 while the latter is in its work-clamping position shown in Fig. 3 and whichrocking'of the bending die is produced by a forward and upward swinging of the wing which the anvil die 13 is moved away from the lower clamping "die 12 to release the bent workpiece and to permit the insertion of another workpiece to 'be bent.

Theswinging of the wing 20 to produce the-bending and return movements of the die 14is produced by a suitable power means which is here shown as being a double-acting fluid pressure'responsive cylinder device-98. The cylinder device 98 ismounted on the support-37 of the main frame member 17 and includes a 'slidable crosshead 99 connected with the outer end of a piston rod 100. The inner end of the piston rodris connected with a piston which is movable in opposite directions in the cylinder device 98 in response to fluid pressure supplied to, and exhausted from, the cylinder device through conduit members 102 and 103.

Movement supplied by the cylinder device '98 is transmitted to the wing 20 through a pair of curved connecting links 105 whose rear ends are connected tothe crosshead 99 We pivot pin 106, and whose forward ends are connected to the wing by the pivot pin 107 of a suitable bracket 108. During the bending stroke thereof, the wing 20is swung forwardly and upwardly from its full line initial position shown in Figs. 3 and 4 to the broken line position 20* of Fig. 4 and, during the return stroke of the wing, it is swung forwardly and downwardly to return the same to the initial position.

It is important that the bending die 14 occupy the initial position mentioned above and shown in the drawaings when' the workpiece :15 is, placed inthemachine; and

this positioning of the bending dieis obtained by=cooperation .of the carrier 83 with the support portion 18 of the main frame member 17. For this purpose, the support .portion 18 is provided across the frontedge thereof with an abutment portion 110 in the form of a forwardly-projecting lip having a bevel on the underside thereof. Theicarrier 83 is provided across the rear edge thereofwith a locating portion '111 which is engageable with the abutment'portion 110 and includes a projecting flangehaving .aibevel thereon which engages and matches withcthebevelon the underside of the abutment portion,

The correct initial positioning of the as shown in :Fig. 3. bending diexl'4is obtained when the wing 20 has been returned'to the position where the locating portion 111 of the carrier 83 is in such matched engagement with the abutment portion 110 of the frame member 17.

The ipivotmeans, by which the'wing 20 and the .cariierf83 are swingably fulcrumed on the frame structure 11 is an important part of the present invention by whichproper control of the carrier and of the bending die .14 is :achieved during the bending operation, and which :pivot means will be described next. The pivot means for the wing 20 comprises a pair of main pivot pins 113 and 114 carried by the side walls 34 and 35 I and on which the eye-shaped end portions 115 and 116 of the yoke arms 80 and 81 of the wing are swingably journalled. The pivot means for the carrier 83 comprises a pair of auxiliary pivot pins 117 and 118 which are also carried bythe side walls 34 and 35 but are in an offset or eccentric relation to the pivot pins 113 and 114. As shown in the drawings, the pivot'pins 113 and 114 for the yoke arms of the wing20 project from the walls 34 and '35 on the outer'sides thereof, whereas the pivot pins 117 and 118-for the carrier 83project from the inner sides of'these walls.

The main pivot pins 113 and 114 can be formed on the side walls '34 and 35 but, as here shown, are'preferably in the .form of stem extensions of mounting flanges 113 and'11'4 and project through suitable openings'of the side walls. The mounting flanges 113 and 114* are secured against the side walls 34 and 35 by suitable screws 119.

The pivot pins 117 and 118 for the carrier 83 can be formed as projections on theside walls 34 and 35 but, in accordance with the present invention, are preferably separate from the side walls and are provided by adapter members 120 and 121 which are mounted on such side walls.

The adapter members 120 and 121 are here shown as each comprising a disk portion 122 having a pivot pin secured to the side walls 34 and 35 or to the mounting flanges 113 and 114 of the main pivot pins 113 and 114.

The pivot pins 113 and 114 for the yoke arms of the wing 20 are provided with central openings through which the mounting stems 123 of the adapter members and 12,1 extend. Nut and washer'retaininge'lements 125 and 126 are applied to the outer ends of the stems 123 for holding the adapter members 120 and 121 in their assembled position and also serve to retain the yoke arms 80 and 81 of the wing in their swingably fulcrumed relation on the main pivot pins 113 and 114. The eccentrically offset relation between the main pivot pins 113, 114 and the auxiliary pivot pins 117, 118 provides 'oifset pivot axes 128, 129 about which the wing 20 and the carrier "83 are respectively swingable. The offset relation of the pivot axes 128' and 129 is illus- "7 trated in the drawings, particularly in Figs. 3, and 6 and in the diagrammatic view shown in Fig. 7.

The swingable connection of the carrier 83 with the pivot pins 117 and 118 is provided with a pair of substantially L-shaped yoke members or brackets 130 and 131 which are connected with the carrier by suitable attaching screws 132. The yoke members 130 and 131 comprise connected base and yoke arm portions 133 and 134 of which the arm portions 134 have slot-like guideways 135 therein in which the pivot pins 117 and 118 are received. The base portions 133 of the yoke members 130 and 131 are seated on the carrier 83 and are clamped thereagainst by the attaching screws 132.

Because of the eccentric or offset relation of the pivot axes 128 and 129, the carrier 83 will have a controlled movement during the swinging of the wing 20 which is produced by a reaction force developed between the yoke arm portions 130 and 131 and their associated pivot pins 117 and 118. The diagrammatic view of Fig. 7 graphically illustrates the control movement to which the carrier 83, and the bending die 14 supported thereby, are subjected during the bending stroke of the wing 20 in response to the offset relation of the pivot axis 129 of the carrier relative to the pivot axis 128 of the wing. Thus, as shown in Fig. 7, the carrier 83 has a slower rate of actuation or lags behind the wing 20 due to the reaction force applied through the yoke arms 130 and 131, during the forward and upward bending-stroke swinging movement of the wing. In other words, the carrier 83 has a backward movement imparted thereto relative to the wing 20 at the same time that the carrier is being actuated by the forward and upward swinging movement of the wing.

To illustrate this lagging or relative backward movement of the carrier 83, Fig. 7 shows successively different positions of the wing 20 which are represented by successive swing lines 137, 138, 139 and 140 and which swing lines are spaced apart by increments of twenty-two and one-half degrees. The lagging or backward movement of the carrier 83 relative to the wing 20 is represented by the successively different positions of the locating portion 111 of the carrier relative to the swing lines 137, 138, 139 and 140 and by the dimensional distance lines 141, 142, 143 and 144 indicating the varying amounts by which the carrier has lagged behind the wing.

The actuation of the bending die 14 by the wing 20 is controlled by this lagging or relative backward movement of the carrier 83 and causes the bending operation to be carried out on the workpiece 15 in such a manner that the excess metal in the unslotted portions 27 and the flanges 23 of the workpiece will be upset or otherwise distributed and, at the same time, confined to the planes of the flanges so that the bending of the flanges is carried out smoothly and without buckling or wrinkling thereof. When the bending operation has been completed and the wing 20 is swung back to its initial position shown in Fig. 3, the control movement imparted to the carrier 83 through the yoke members 130 and 131 by reason of the offset relation of the pivot axis 129, causes the carrier to be returned to its initial position in which its locating portion 111 is in engagement with the abutment portion 118 of the frame structure.

The offset relation shown in the drawings between the pivot axes 128 and 129 is appropriate for a bending operation for producing a bend of a given radius of curvature as, for example, the bend 25 of the workpiece shown in Fig. 14. The machine 10 is readily adaptable, however, for producing other bends of different radii of curvature. By providing the pivot pins 117 and 118 for the carrier 83 as portions of the adapter members 120 and 121, it will be observed that by substituting in the machine 10 other such adapter members having a different eccentricity or offset relation for the pivot pins .117 and 118, these pivot pins will have correspondingly different fulcrum point locations in the slots 135 of the yoke arms 134 and the controlled actuation of the carnier 83 and the bending die 14 will then be appropriate for producing bends having radii of curvature corresponding with the eccentricities selected for the pivot pins 117 and 118.

From the construction described above for the adapter members 120 and 121, it will also be observed that these members are readily detachable from the side walls 34 and 35 of the bending machine 10, and that other such adapter members having a ditferent selected eccentricity for the pivot pins 117 and 118 can be readily assembled into the machine. When such other adapter members are assembled into the machine, the pivot pins 117 and 118 thereof will have a different fulcrum point location in the slots 135 of the yoke arms 134, such that for a bend having a smaller radius of curvature the fulcrum point location of the pivot pins in the slots 135 will be relatively closer to the pivot axis 128 of the wing and for a bend having a larger radius of curvature the fulcrum point location of the pivot pins 117 and 118 in the slots 135 will be relatively more remote from the pivot axis 128.

It will be understood, of course, that when the machine 10 is being adapted for making bends of other curvatures, other anvil dies will need to be substituted in the machine and, in each case, the anvil die to be used will be one whose edge portion 13 has a radius of curva ture corresponding with that of the bend desired to be made. If the bend to be made is one having little or no radius, then the anvil die 13 will be one whose edge portion 13 is primarily a corner edge.

Since it is important that the carrier 83 and the bending die 14 start from and be returned to the initial position shown in Figs. 3 and 6, it is necessary that the yoke members 130 and 131 have an adjustable connection with the carrier so as to properly accommodate the pivot pins 117 and 118 of the different adapters 120 and 121 which may be selected for different desired radii of curvature. For the purpose of this adjustable connection, the carrier 83 is provided with dovetail slots 146 adapted to receive shiftable plate-like nuts 147 for the attaching screws 132. The dovetail slots 146 include access openings 148 at one end thereof of a size to permit insertion of the nuts 147 into the slots. By releasing the clamping action of the screws 132, the yoke members 134 can be adjustably shifted on the carrier 83 to a position appropriate for the eccentricity of the pivot pins 117, 118 of the particular adapter members 120, 121 with which the machine 10 is then being equipped.

When the yoke members 130 and 131 have been thus adjusted on the carrier 83 to the setting appropriate for the pivot adapter members 120 and 121 which have been installed in the machine, the clamping screws 132 are tightened so that these yoke members thereafter remain in a fixed position on the carrier for the full cycle of the bending operation.

For the construction of the machine 10 as shown in Figs. 1 to 8 inclusive of the drawings and described above, it will be accordingly seen that the carrier 83 has a translatory movement relative to the wing 20 and along the guideway 86 and that during the bending operation the wing will swing about the pivot axis 128 while the carrier S3 and the bending die 14 will swing about the offset pivot axis 129. The reaction force, to which the carrier 83 is subjected during the bending operation by reason of the ofiset relation of the pivot axis 129, will cause the forward and upward swinging of the bending die 14 around the anvil die 13 to take place at a relatively slower rate than the forward and upward swinging of the wing 21 as explained above, but the return swinging of the wing will nevertheless always return the carrier 83 and the bending die 14 to their desired initial position shown in the drawings. Because of the relatively slower movement or lagging action of the carrier radii .on different workpieces desired to be bent. greater adaptability ofthe bending machine 151 results 283 .andthe bendingdie .1-4 relativezqto athe wing. during the bending operation, it will zhezseen that;the:overlapping aportions '93 of :the bending die 14 will be effective :to

hold :the .flanges 23 of theworkpiece .15 .for confining :the .unnotched .portions'27 thereof against wrinkling or buckling during the bending of the :flanges :within their .own planes.

Figs. 9110 .12 inclusive of the drawings show :amodified bendingmachine 151 which is ofrthe sameconstruc- ;tion .as the bending machine with respect :to'the gen- .eral organization thereof :and which uses thesame .dies 12, 13 and 14 for producing similar bending operations on a workpiece 152 which is of the same character as the workpiece .15. The modified tbending machine 151, 'however, is more :readilyadaptable iorbe'nds of :diirerelzlnt T is from a dirierentand novel .form .ofpivot means 153 em- :ployed in the machine by whichdiiferent eccentricities for the pivot pins of thebending die carrier can L-beobtained without need for removing'and substituting steps to becarried outwith respect to pivot'pin adapter members such'as the adapter members :120 and 121 described abovein the machine 10.

-In the modified machine 151 a bending @die carrier or slip rplate.8'3 is provided and :has yoke members 130 and 131 thereon whose yoke arms 134 are provided twiththe guide slots 135 for receiving pivot pins 153. These pivot pinsprovide a pivot axis $54 which is offset from a pivot axis .155 of the wing 20. The pivot pins 153 are preferablynot .fulcrumeddirectly in the slots 135 but are provided with crosshead blocks 156 which aiford a larger bearing surface area with the side walls of the slots.

Since the same pivot pin adjusting structures 153 are provided :at both sides of thecarrier 83, only one of these structures need'be described in detail.

To render the pivot pin 153 readily adjustable to different eccentricities relative to the pivot axis 155 of the wing, this pivot pin is mounted on-a slide 1'56which is movable in a {dovetail guideway 157 formed in a mounting plate 158. The plate 158 is mounted on an upright side wall 35 of the machine 151 as by means of screws 159. The slide 156 is provided with a threaded opening 160 and is adjustably movable in the guideway 157 by means of an adjusting screw *161 engaged in the threaded opening.

The screw 161 is provided at the outer end thereof with a knurled actuating knob 162 and ,is rotatably supported and axially 'held 'in a support plate 163 secured on a bracket extension 164 of the mounting .plate 158.

Upon rotation of the screw 161 in one direction or the other, the slide 156 will be moved along the guideway 157 and the pivot pin 153 will be shifted toward or away from the main .pivot axis 1'55 to the desired eccentric setting. "During such shifting of the pivot pin 1153 by the adjusting screw 161, the yoke member 130 'is adjustably shiftable on the carrier .83 by reason of alloosened condition of theclamping screws .132. "The adjustnient of the pivot pin 153 to the desired eccentric position by the adjusting screw 161 thus also causes adjust- ,able shifting of the yoke member 130 along {the carrier 83.

When the desired .settingforthe pivot pin 153 has been reached, the clamping screws 132 are tightened .to .conmet the yoke member 130 in a fixed relation tto .the .carrier 83. To relieve the adjusting screw 1610f the need to hold the slide 156 against further shifting along the guideway 157 after the desired setting for the pivot pin *face :of the .:slide.;1.56 :and zapplyclampingspressureitothe .esIide-inresponse to tightening of the .screws 166,.

The functioning of the modified bending machinelgl in performing a bending operation on the flanged work- 7 piece 152 :is substantially the same as has already-been the particular offset ,relation'or eccentricity provided for the pivot pin 153 of the carrier 83. The extent to which the carrier 83 has lagged behind-.thewing. 20 by thetime that the bending operation on the workpiece 152 iscompleted is represented bythe dimensional distance line 170.

The mounting plate 58 is preferably provided with a graduated scale 172 to indicate diiferent radii of curvature for which the pivot pins 153 can beset bymovement of the slide 156 along the guideway 157. The heel end 156 of the slide cooperates with the graduations of the scale 172 to indicate the ,radius ,for which the slide has been adjusted by the screw 1631.. Figs. .10 and l2 show the die 13 and'the setting of the pivot pin 153 of the machine 151 as being for a bend of a larger. radius of curvature than that of the bend 25 being formed by the machine 10.

From the accompanying drawings and the foregoing for the bending die carrier to thereby eliminate the need for the cooperating gear members heretofore used for controlling the movements of the bending diecarrier and the bending die. It will now also be understood that the present invention providessuch a novel-construction for metal bending machines wherein the machines are readily adaptable for use in producing bends of different radii of curvature for different desired workpieces.

Although the novel bending machines of the present invention have been illustrated and-described herein to a .somewhat detailed extent, it will be understood, of course, that the invention is not to be regarded as being limited correspondingly in scope but includes all changes and modifications coming within the terms of the claims hereof.

Having described my invention, I claim:

1. In abending machine, a frame structure'comprising stationary andmovable frame members, a pair of relatively movable work clamping dies mounted on said frame members and adapted for clamping engagement with opposite sides of a workpiece to be-bent and one of which dies is an anvil die, means for actuating'the movable framemember for causing said dies to clamp the workpiece, a third frame member having a guideway thereon, first pivot means connecting said third frame member with said stationary'frame ,member for swinging about a first pivot axis, mea ns for causing theswinging of said third frame member, a carrier on said third frame member and movable thereon along said guideway, a bending die on said carrier and rockably movable 'relative to said anvil die for bending the workpiece against the latter in response to the swinging of said third frame member, and control means associated with said "first pivot'means and efiectiveon said carrier for controlling the movement of the latter along said guideway during the swinging of said third frame member, said control ,means comprising auxiliary pivot means connecting said carrier with said stationary frame member for swinging about a second pivot axis :eccentrically ofiset from :said first pivot axis.

.2. A bending machineas defined in claim 1 and wherein ,said au giliary pivot means .comprises ;a .pair vof pivot "f1 members projecting from said stationary frame member and a pair of slotted yokes connected with said carrier and fulcrumed on said pivot members. V

3. A bending machine as defined in claim 1 and wherein said control means also comprises means effective on said auxiliary pivot means for varying the eccentricity of the offset relation of said second pivot axis.

4. A bending machine as defined in claim 1 and wherein said stationary frame member has spaced walls thereon and said carrier has a pair of spaced yokes thereon. and wherein said first pivot means comprises first pivot members on said walls and said auxiliary pivot means comprises second pivot members having said yokes fulcrumed thereon, said second pivot members being detachably connected with said walls.

5. A bending machine as defined in claim 1 and wherein said stationary frame member has spaced walls thereon and said carrier has a pair of spaced yokes thereon, and wherein said first pivot means comprises first pivot members on said walls and said auxiliary pivot means comprises second pivot members, having said yokes fulcrumed thereon, said second pivot members comprising mounting stems extending through said first pivot members substantially coaxially of the latter and pivot pins connected with said stems in ofiset relation thereto and fulcrumably engaged by said yokes.

6. In a bending machine, a frame structure comprising stationary and movable frame members, a pair of relatively movable work clamping dies mounted on said frame members and adapted for clamping engagement with opposite sides of a workpiece to be bent and one of which dies is an anvil die, means for actuating the movable frame member for causing said dies to clamp the workpiece, a third frame member having a guideway thereon, pivot means on said stationary frame member and comprising eccentrically offset first and second pivot pin portions providing two parallel pivot axes, said third frame member being fulcrumed on said first pivot pin portions for swinging about one of said pivot axes, means for causing the swinging of said third frame member, a carrier on said third frame member and movable thereon along said guideway, a bending die on said carrier and rockably movable relative to said anvil die for bending the workpiece around the latter in response to the swinging of said third frame member, and means connected with said carrier and fulcrumed on said second pivot pin portions for swinging about the other of said pivot axes, the co-operation of the last-mentioned means with said second pivot pin portions being effective for moving the carrier along said guideway in response to the swinging of said third frame member.

7. In a. bending machine, a stationary first frame member having a die support including an abutment portion, a second frame member movable toward and away from said first frame member, a pair of die members on said first and second frame members and adapted for clamping co-operation with a work-piece disposed between said die members, the die member on said second frame member being an anvil die member, actuating means for moving said second frame member to cause said die members to clamp said workpiece, a third frame member having a guideway thereon, a carrier adapted for movement along the guideway of said third frame member and having a locating portion engageable with said abutment portion, pivot means on said stationary frame member and comprising eccentrically offset first and second pivot pin portions providing two parallel pivot axes, said third frame member being fulcrumed on said first pivot pin portions for swinging about one of said axes and having an initial position with the locating portion of said carrier in engagement with said abutment portion, means for swinging said third frame member through bending and return strokes for actuating said carrier and of which the bending stroke movement is in a direction away'from said first frame member, a bending die on said 1 carrier and co-operable with said anvil die. member for bending the workpiece around the latter during the bending stroke swinging of said third frame member, and means connected with said carrier and fulcrumed on said second pivot pin portions for swinging about the other of said pivot axes, the cooperation of the last-mentioned means with said second pivot pin portions being effective for controlling the rate of actuation of the carrier by said third frame member, said carrier having a resulting control movement relative to the third frame member and along said guideway in a direction toward said abutment portion during the bending stroke movement of said third frame member.

8. Abending machine as defined in claim 7 and wherein the eccentricity and direction of ofiset between said first and second pivot pin portions are such that the resultant movement of said carrier during the bending stroke swinging of said third frame member is a movement in the same direction as said third frame member but at a slower rate of movement.

9. A bending machine as defined in claim 7 for operation on a workpiece having web and flange portions to be bent and wherein the die member on said first frame member and said bending die have angularly disposed confining portions adapted to overlap side portions of said anvil die in confining relation to said flange portions.

10. A bending machine as defined in claim 7 for operation on a workpiece having web and flange portions to be bent and wherein the die member on said first frame member and said bending die have angularly disposed confining portions adapted to overlap side portions of said anvil die in confining relation to said flange portions, and wherein the eccentricity and direction of offset between said first and second pivot pin portions are such that the resultant movement of said carrier during the bending stroke swinging of said third frame member is a movement in the same direction as said third frame member but at a slower rate of movement.

11. In a bending machine, a frame structure comprising stationary and movable frame members, a pair of relatively movable work clamping dies mounted on said frame members and adapted for clamping engagement with opposite sides of a workpiece to be bent and one of which dies is an anvil die, means for actuating the movable frame member for causing said dies to clamp the workpiece, a third frame member having a guideway thereon, pivot means on said stationary frame member and comprising eccentrically offset pivot pin portions providing two parallel pivot axes, said third frame member being fulcrumed on certain of said pivot pin portions for swinging about one of said pivot axes, means for causing the swinging of said third frame member, a carrier on said third frame member and movable thereon along said guideway, a bending die on said carrier and rockably movable relative to said anvil die for bending the workpiece around the latter in response to the swinging of said third frame member, and yoke means connected with said carrier and fulcrumed on others of said pivot pin portions for swinging of the carrier about the other of said pivot axes, said yoke means being effective between said other pivot pin portions and said carrier for moving the latter along said guideway in response to the swinging of said third frame member.

12. A bending machine as defined in claim 11 and wherein said yoke means comprises yoke members having bearing slots therein and fulcrumed on said other pivot pin portions by engagement of the latter in said slots, and wherein said yoke means is adjustably connected with said carrier.

13. In a bending machine, a frame structure comprising stationary and movable frame members, a pair of relatively movable work clamping dies mounted on said frame members and adapted for clampingfengage- 13 ment with opposite sides of a workpiece to be bent and one of which dies is an anvil die, means for actuating the movable frame member for causing said dies to clamp the workpiece, a third frame member having a guideway thereon, pivot means on said stationary frame member and comprising eccentrically ofiset first and second pivot pin portions providing first and second parallel pivot axes, said third frame member being fulcrumed on said first pivot pin portions for swinging about said first pivot axis, means for causing such swinging of said third frame member, a carrier on said third frame member and movable thereon along said guideway, a bending die on said carrier and rockably movable relative to said anvil die for bending the workpiece around the latter in response to said swinging of said third frame member, yoke members having bearing slots therein, and means connecting said yoke members with said carrier and providing for adjustment of the yoke members on the carrier and in parallel planes extending transverse to said first pivot axis, said second pivot pin portions extending into said bearing slots as fulcrums for said yokes and providing for swinging of said carrier about said second pivot axis during the swinging of said third frame member about said first pivot axis.

14. A bending machine as defined in claim 13 and which includes adapter members detachably connected with said stationary frame member, and wherein said first and second pivot pin portions comprise portions of said adapter members.

15. In a bending machine, a frame structure comprising stationary and movable frame members, a pair of relatively movable work clamping dies mounted on said frame members and adapted for clamping engagement with opposite sides of a workpiece to be bent and one of which dies is an anvil die, means for actuating the movable frame member for causing said dies to clamp the workpiece, a third frame member having a guideway thereon, pivot means on said stationary frame member and comprising eccentrically offset first and second pivot pin members providing first and second parallel pivot axes, said third frame member being fulcrumed on said first pivot pin members for swinging about said first pivot axis, means for causing such swinging of said third frame member, a carrier on said third frame member and movable thereon along said guideway, a bending die on said carrier and rockably movable relative to said anvil die for bending the workpiece around the latter in response to said swinging of said third frame member, yoke members having bearing slots therein, means connecting said yoke members with said carrier and providing for adjustment of the yoke mem bers on the carrier and in parallel planes extending transverse to said first pivot axis, said second pivot pin members extending into said bearing slots as fulcrums for said yoke members and providing for swinging of said carrier about said second pivot axis during the swinging of said third frame member about said first pivot axis, and means adjustably mounting said second pivot pin members on said stationary frame member and providing for variation of the eccentricity of said second pivot axis relative to said first pivot axis.

16. A bending machine as defined in claim 15 and wherein the connecting means for said yoke members- References Cited in the file of this patent UNITED STATES PATENTS 383,047 Downes May 15, 1888 928,616 OBleness July 20, 1909 935,299 Denham Sept. 28, 1909 1,029,012 Higgin June 11, 1912 2,299,537 Goldsmith et al. Oct. 20, 1942 2,568,691 I Wildman a Sept. 18, 1951 2,596,848 Green May 13, 1952 FOREIGN PATENTS 76,795 Germany Aug. 15, 1894

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