US2680467A - Machine for shaping metal workpieces - Google Patents

Description

June 8, 1954 A. M. REDMAN MACHINE FOR SHAPING METAL WORKPIECES Fried Jan -26, 1951 June 8, 1954 A. M. REDMAN MACHINE FOR SHAPING METAL WORKPgEQES Filed Jan. 26, 1951 Jr Z 29 20 June 8, 1954 M, REDMAN 2;80,467

MACHINE FOR SHAPING METAL WORKPIECES Filed Jan. 26, 1951 3 Sheets-Sheet 3 m e-MM? Patented June 8, 1954 UNITED STATESv 2,680,467 7 MACHINE FOR SHAPING METAL WORKPIECES n, Croydon, England, asools & Products Limited, British company Albert Maurice Redma signor to 'Redman T Croydon, England, a

Application January 26, 1951,

10 Claims. 1

This invention comprises improvements in or relating to methods of shaping metal work-pieces and to metal-working machines therefor, and its object is to provide an improved method and construction of machine for the cold bending and shaping of work-pieces such as metal bars, rods, strips, tubes and the like, which method and machine are moreover particularly suitable for bending work-pieces into the form of a complete ring or closed figure, or for shaping those which are already in this form.

According to the present invention a method of shaping a metal work-piece consists in placing the work-piece against a former, pressing a shoe on to the Work-piece toward the former, so that the shoe forces the work-piece to conform to the former at one part of its length, and thereafter while maintaining pressure on the shoe toward the former, shifting the place of application of such pressure progressively along the shoe and e shoe and former one over the other with the work-piece between them to cause the metal of the Work-piece to flow into conformity with the shape of Preferably the further comprises in a Serial No. 207,879

to swing it is obviated and this fact is not only an advantage in itself but renders a machine according to the present v as Patent No. 2,636,537 enables curved flanged the combination of a former, a press-member opposed to the former so as to bear on a work-piece placed on the former, a fluid-.pressure-operated ram behind the pressmember to urge it toward the former, a carrier on shoe can act progressively along the work-piece without lateral sliding movement thereon.

along the back of the shoe, the movement being somewhat analogous to sliding about its fulcrum and the shoe work-piece. Thus the need for providing some independent means, such as a Winch or hydraulic traversing cylinder, to haul or push upon the arm rolls upon the work to be produced without undesirable distortion or crinkles. The shoe presses the workpiece against the former over a narrow area "only at any one time and this narrow area of pressure is caused to travel slowly and progressively over the Work-piece so that the metal of the workpiece flows and the work-piece is gradually smoothed or ironed to the shape of the former;

work-piece show a very slight thickening toward their edges along the inside of the curve.

In the preferred form the movement of the fulcrum of the carrier is effected by two hydraulic piston and cylinder units acting in directions substantially at right-angles to one another. The may swing, in a substantially complete ring. 7

L One form of machine in accordance with the invention will now be described, byway of example, and with reference to the accompanying diagrammatic drawings in which:

Figure 1 is a diagrammatic plan view of the machine, a Figure 2 is a diagrammatic elevation in part section on the line 2-2 of Figure 1,

Figure 3 is a further diagrammatic plan view showing the parts in different relative positions to those of Figure 1,

Figure 4 is a diagram to illustrate the movements of the carrier and its fulcrum during operation of the machine,

Figure 5 shows a former block for the machine in plan view, and

Figure 6 is a diagram to illustrate further the operation of the machine.

The machine has a frame H comprising a base plate 12, side walls 13 and a rear wall M. A bridge member l5 extends across the top of the machine near the front thereof between the side walls I3, and secured to the underside of the bridge member midway along its length is a former support 40 carrying on its underside a male former having a profile 11 which is elliptical in plane and semi-circular in vertical cross-section. The elliptical former is symmetrically mounted with respect to the bridgemember l5, with its major axis parallel to the side walls 13.

At the lower part of the machine two vertically spaced horizontal plates l8, l9 extend across the machine between the side walls and from the front to the rear, the lower plate 18 being supported at the front of the machine by a low vertical wall 20. A fulcrum block 2|, which is circular in plan, slides horizontally between the two plates i8, i9 and has journalled in it a vertical pivot pin 22 disposed directly beneath the former l6, which pin serves as a fulcrum about which swings an elongated horizontal cantilever arm 23, shown extending forwardly of the machine in Figures 1 and 2. The circular fulcrum block has an internal cavity 24 through which the pivot pin 22 passes.

The cylinders 25, 25 of a pair of hydraulic piston and cylinder units are arranged horizontally between the plates l3, l3 and are pivotally connected to the machine frame, one near each rear corner of the frame. The cylinders have piston rods 21, 28 which extend towards the fulcrum block 21, the two piston and cylinder units being arranged very nearly at right-angles to one another as viewed in plan, and the rods pass into the cavity 24 within the block 2| through apertures in the wall surrounding the cavity. The piston rod 28 has an eye 29 and the piston rod 21 a forked eye 30, and the pivot pin 22 journalled in the fulcrum block 2! passes through the eyes 29, 30 the eye 29 being fitted between the forks of the eye 30. Thus it will be clear that the fulcrum block 21 and pivot pin 22 for the arm 23 are movable bodily in any direction in a horizontal plane under the control of the two cylinders 25, 26,; the upper horizontal plate 19 having an aperture 3| to allow the pivot pin to move laterally. The elongated arm 23 is therefore capable of swinging in a horizontal plane about its fulcrum 22 located within the closed figure of the profiled face of the former IS in a manner to change the crossing angle of the longitudinal axis of arm 23 and the former profile and through a complete revolution of the former.

The arm 23 has secured face a horizontal strap 32, and a second parallel stra 33 is spaced vertically above the strap 32 and is also secured to swing with the arm. The cylinder 34 of a horizontal hydraulic piston and cylinder unit is mounted between the outer ends of the straps 32, 33 and has a piston rod 35 extending parallel with the arm toward a vertical projection of the pivot pin 22. The axis of the piston rod 35 is on a level with the horizontal centre-line of the former profile l1, and the straps 32, 33 are spaced equi-distantly below and above the former respectively. Towards its in-- nor end, that is the end nearer the pivot pin, the lower strap 32 is broadened out to form a table 36 which swings with the arm 23.

A shoe 31, for shaping the work-piece upon along its upper surthe former I6, is constituted by a heavy cast mild steel block, rectangular in plan and in crosssection, and resting horizontally upon the table 36 over which it is free to slide beneath the upper strap 33. The block 31 has a horizontal recess 38 extending along its surface which faces H5, and three hardened steel inserts or liners 33 are fitted along the side and bottom faces of the recess, to resist wear and are so shaped that when they are in position the vertical cross-section of the recess, which is uniform along the whole length of the recess, is semi-circular to correspond to the shape of the outer or convex surface of the finished work which it is desired'to produce upon the machine. The longitudinal centre-line of the recess 38 is at the same height as that of the male former profile I6, and the shoe 31 with its longitudinal recess 33 constitutes a female former movable with respect to the male former 16, with which it cooperates to shape a work-piece held in place between the former l6 and the shoe The piston rod 35 of the piston and cylinder unit, mounted on the swinging arm 23, has at its inner end a forked adaptor ii which carries a roller 42 mounted centrally of the arm 23 to rotate about a vertical axis, and under the action of the hydraulic cylinder 34 the roller 32 bears upon the back of the shoe 31 to cause the shoe to shape a work-piece against the former If.

The operation of the machine will now be described. The pressure exerted by the hydraulic cylinder 34, clearly, always acts along the centreline of the swinging arm 23, directly towards a vertical projection of the pivot pin 22; when this line of pressure is normal to the horizontal centre-line of the work-piece on the former it at that part thereof upon which the shoe 31 is hearing, the arm is stable and shows no tendency to swing, but if the line of pressure and the horizontal centre-line of said part of the work-piece on the former are at an angle to one another other than then it will be seen that the force due to the pressure of the cylinder 34 can be resolved into a component normal to the former l5 and work-piece and a component parallel thereto, and the latter component of force tends to cause the arm 23 with the hydraulic pressure cylinder 34 to swing about its pivot 22. By moving the fulcrum block 2! under the control of the hydraulic cylinders 25, 23 it is possible to adjust the line of pressure of the cylinder 33 angularly with respect to the former l3 and workpiece until a point is reached when the aforesaid parallel component of force becomes sufiicient to overcome the frictional forces of the parts and the resistance of the work-piece to the shoe 31 and therefore to swing the arm 23, and it will be realised that the arm 23 can be kept swinging, or stopped, or caused to swing in the reverse di rection merely by effecting suitable movements of the fulcrum block 21, and that the speed of swing is controllable in the same manner.

Thus, by mounting the swinging arm 23 of the bending machine according to the present invention in such manner that the fulcrum block 2| is movable at will as desired, the need for providing independent means, such as a winch or hydraulic traversing cylinder, for swinging the arm by hauling or pushing upon it, as is often found in bending machines, is obviated. In the machine illustrated'and described herein, the arm 23 and the pressure cylinder 34 it carries are capable of rotating through a complete revolution about the pivot pin 22 and around the former Hi, the arm 23 passing beneath the bridge-member l5 and swinging in the space within the side walls 13 and rear wall 14 of the machine frame H, and when the hydraulic cylinder 33 is exerting pressure the arm 23 may be caused to perform such a revolution, either in stages or continuously, as

towards the former the swinging arm 23 and section in one and the same operation, but shaping of the cross-section of a work-piece will be only, for the sake of simplicity). The dimensions of the profile periphery l1 and the inner dimensions of "the ring to be shaped, as considered in plan View, are substantially the same, and the Work-piece is placed around the elliptical former profile [7, after having first of the fulcrum and swinging arm at 51 and it, respectively, and the position of shoe 3? atthe commencement of the forming operation is represen ed at '52. The position of the fulcrum on the major axis of the former ellipse and intermediate between the central position 5i and the projection of the former outline as is represented. at 53 and the dotted line '5'i53 indicates the path of the forward movement followed by the fulcrum.

The shoe 3? is positioned so that the right-hand of it, as viewed looking :along the arm toit with the work-piece thereon, pressure is then applied by the cylinder 34 so that the shoe is forced toward and driven tightly on to it around the work-piece, which is represented'in Figures 1, 2'and 3 in phantom lines at H, over a limited area in front of the roller. This action shapes the work-piece to the former profile and gives it the required semi-circular cross-section over part of the limited area of the work-piece with which the shoe is now in contact.

quently the arm 23 is translated from the stable condition in which the line of pressure of the hydraulic cylinder is coincident with the major axis of the former :l 6 into .an unstable condition in which there is a component of force tending .to move the arm .23 bodily .to the left, and as the plan, and follows the fulcrum.

The unstable condition of the .arm is illustrated in plan View in Figure :6, in which the line of pressure P of the hydraulic cylinder lies atan angle other than to a line T tangential to the part of the former I6 upon which the shoe 3! is thcshoe :upon the work-piece is transferred gradually and progressively along the work-piece, and

work-piece between the shoe 3-! and male former cross-section of the work-piece as the shoe rolls thereon, the work is formed without producingany undesirable crinkles or distortion; "the metal thickens up slightly on the inside of the curve but is not over-strained in any way.

developed length of ithe' for'mer first stage the fulcrum is moved along the path 54 to a position 55, and

stage, and finally forwardly and to the left along position :53 for the fourth stage and to completethe cycle. Ihe arm v23 is in the positions shown dotted line at 62 and t3 when the fulcrum is at rest ,in positions 58 and 60 "respectively, andin each position the pressure of the cylinder 34 is released and the shoe 3'! the swinging arm in the present machine has a is slid from right to left across the table, as viewed moving fulcrum, sim'lar circumstances, dependlooking along the arm 23 towards the fulcrum. ent upon the curvature of the part of the former When the shaping of the work-piece has been against which the shoe is pressing the work-piece, completed, the pressure on the back of the shoe 5 affect its movement; for example, the arm will 31 is released and the shoe is removed from the tend to speed up when the shoe is shaping the work; the finished work can then be replaced by a first and third quarters of the work-piece and will fresh work-piece and the cycle of operations rebe slowed down when forming the second and peated. The former is collapsible, being made up fourth quarters. The constant delivery pump and from a number of sections detachable one from the aforementioned relief valve keep the pressure another, in order that it shall be capable of reexerted by the cylinder 34 substantially constant moval from the finished work-piece which surwhether the movement of the shoe 31 is uphill rounds it, or downhill, but it is also important to ensure Thus, Figure 5 shows in plan an elliptical that the movement of the arm 23 and shoe 31 former made up of five separable sections 64, 65, should be sufliciently slow to allow the metal of 6B, 61, 68, with disconnectable brackets 59 for the Work-piece time to flOW as it is p and holding the sections together, and it will be clear this may be effected either by varying the path that after a double-flanged work-piece has been of the fulcrum or by slowing up the fulcrum bent to shape around the former, the former may movement over the parts of its path which it be removed by first knocking out the middle ec-- traverses when the shoe is moving downhill so tion 68 and then sliding first sections 86 and 61', that unduly rapid folding action upon the workand then sections 64 and 65, inwards. piece is prevented from occurring at any point in It is to be understood that Figure 4 is merely a e cycle. diagram for the purpose of explaining the work- Although a particular machine and the p oducing of the machine and that the path of th fultion of a specific form of work is described herein crum shown is only an approximate one; moreby way of example, it will be appreciated that over although the arm 23 is represented at 54, 62 considerable modification and addition is possible and 63 as being in each case in a position normal without depart n from the Scope of the vento the horizontal centre-line of the work-piece tion.

and former at that point, this will not in actual In most cases it is desired to clamp the Workfact be so, as the arm 23 always tends to lag piece to the former at some stage in the operabehind the fulcrum in its swinging owing to the ti n n f n hr h the bending n h pfriction in the machine and the resistance of the ing operation and for this purpose a hydraulic work-piece to the shoe 31. This can be comclamp such as that upon the machine described pensated for at the end of each cycle by carrying in the above mentioned Patent No. 2,636,537, or the fulcrum past the position 53 for a short dis a n mb r f h lamps, c uld b provided. If tance in order to bring the arm 23 round in front desired, an au y Shoe control y u c ylof the machine far enough to complete the shapi r as described in a -p nd s appli ation ing of the work-piece; the fulcrum can then, if m y be car ied by the swinging arm to assist in desired, be returned to the position 53 for com- Sw t S angu rly and in pulling the mencement of the next working cycle. shoe off the work, to which it may tend to stick.

Figure 3 shows in plan view the parts of the I claim: machine in the relative positions which they n a m ta -Work ma hine the combinaoccupy near the completion of the shaping of the tion of a machine frame, a former secured on said first quarter of the work-piece. frame and having a front face to receive a work- The pressure employed in forming the workpiece for shaping, an elongated arm mounted on piece is high; it may be of the order of 2,000 lbs. the frame to be capable of swinging in front of per square inch. The hydraulic pressure is conthe former about a fulcrum located behind the veyed to the various cylinders of the machine by former in a manner to change the crossing angle reinforced flexible pipes, not shown in the drawof the longitudinal arm axis and the former proings. A constant delivery type pump is automafile, said fulcrum being movable upon the machine tically controlled to maintain the working presframe in the plane in which the arm swings about sure in the various hydraulic circuits. An adsaid fulcrum to afiord pivotal movement of the justable relief valve is provided in the pressure arm about different parallel axes, a press-member line to the swinging pressure cylinder 3 in order u rted in front of the former t be on to prevent excessive fluid pressure in said cylinder work-piece placed against the former, fluid-presduring shaping of the work-piece. sure-operated means mounted on the arm to urge It will be understood that, in a bending mathe press-member toward the former, and fulchine With an arm having 2- fixed fulcrum and crum-moving mean mounted upon the machine provided w th a pr s Cylinder and a S110e frame and operatively connected to the arm at similar to that of the present machine to roll on t fulcrum end theregf behind t former for the Wo -p example a machine as moving said fulcrum to various positions behind scribed in the above mentioned Patent N the former to cause the arm, under the effect of 537, when the shoe is pressing the work-piece to pressure applied to the work-piece by the fluida p Of the former Where the distance f 5 pressure-operated means and press-member, to former profile from the pivot of the arm 1s mswing and hift the place of application f pres creasing, there will be increased resistance to the sure progressively along t workpiece progress of the swinging arm a omp with 2. In a metal-working machine the combinawhen the distance o e former P fi from the tion of a machine frame, a former secured on said Divot is constant, whereas when said distance is frame and having a curved front face to receive decreasing the resistance to swinging is decreased. a workpiece for shaping, an arm mounted on the These conditions under which the resistance to frame to swing in front of the former about a swinging is increased or decreased may be repivot pin located behind the former, a fulcrum garded as analogous to uphill or downhill block in which the pivot pin is journalled which movement of the shoe respectively. Although block is mounted to slide upon the frame in any on a workpiece placed against the pressure-operated workpiece by the fluid-pressure-operated means and press-member, to swing andshift the place of application of pressure progressively along the workpiece.

3. Ina metal-working machine the combination of a machine frame, a former secured on said frame and having a curved front face to receive placed against the former, fiuid-pressure-operated means mounted on the arm to press the shoe 10 to the workpiece by the shoe progressively along the workpiece.

nose to apply the pressure to the shoe which nose moves laterally as t e arm swings thereby shifting the place of contact between nose and shoe along the shoe, and fulcrum-movingcause the arm, when pressure the workpiece the shoe progressively along 6.- In a metal-working machine the combination of a machine frame, a

of the former about a pivot pin located behind the former, a fulcrum block in which the pivot pin is journalled, which block is'mounted to slide between guide plates upon the frame in any direction in the plane in which the arm swings about such pivot pin to afford pivotal movement of the arm about different parallel axes, a press-member supported in front of the former to bear on a workpiece placed against the former, fluid-pressure-operated means mounted on the arm to urge the press-member toward the former, and a pair of hydraulic piston and cylinder units mounted upon the machine frame with their axes lying substantially at right angles to one another in the plane of movement of the fulcrum block, said piston and cylinder units being operatively connected to the fulcrum block for sliding it to various positions to cause the arm, when pressure is applied to the workpiece by the fluid-pressureoperated means and press-member, to swing and shift the place of application of pressure progressively along the workpiece. 8. In a metal-working machine the combination of a machine frame, a former secured on said frame and having a curved front face to receive a workpiece for shaping, an arm mounted on the frame to swing in front of the former in a horizontal plane about a pivot pin located behind the former, a fulcrum block in which the pivot pin is journalled, which block is mounted to slide horizontally between guide plates upon the frame in any direction to afford pivotal movement of the arm about different parallel axes, the flat table on the arm below the former, a shoe able to roll in a horizontal plane of movement on a work piece placed against the former, which shoe rests on the table and is capable of being slid over it linearly and angularly in any direction, a main hydraulic piston and cylinder unit mounted on the arm to press the shoe against the workpiece on the former, said main piston and cylinder unit being provided with a roller nose to apply the pressure to the shoe, which nose moves laterally as the arm swings thereby shifting the place of contact between roller nose and shoe along the shoe, and a pair of fucrum-moving hydraulic piston and cylinder units mounted upon the machine frame with their axes lying substantially at right angles to one another in a horizontal plane, said fulcrum-moving piston and cylinder units being operatively connected to the fulcrum block for sliding it to various positions to cause the arm, when pressure is applied to the workpiece by the main piston cylinder unit and shoe, to swing and effect said lateral movement of the roller nose to shift the place of application of pressure to the workpiece by the shoe progressively along the workpiece.

9. In a metal-working machine the combination of a machine frame comprising a base, supports upstanding from the base and a bridge member extending transversely of the machine between the supports and above the base, a former support member depending from the bridge mem ber, a former secured above the base upon the lower end of the former support member, said former having a curved profiled face to receive a workpiece for shaping, which profiled face extends endlessly all around the former so that said face is in the form of a closed figure, an elongated arm mounted on the frame to be capable of swinging in a horizontal plane about a fulcrum located within the closed figure of the profiled face of the former in a manner to change the crossing angle of the longitudinal arm axis and the form er profile and through a complete revolution around the former, said fulcrum being movable upon the machine frame in the horizontal plane to afford pivotal movement of the arm about different parallel axes, a press-member supported on the arm to bear on a workpiece placed against the former, fluid-pressure-operated means mounted on the arm to urge the press-member toward the former, and fulcrum-moving means mounted upon the machine frame and operatively connected to the arm at the fulcrum end thereof within the closed figure of the profiled face of the former for moving said fulcrum to various positions within the closed figure of the profiled face of the former to cause the arm, under the eifect of pressure applied to the workpiece by the fiuid-pressure-operated means and press-member, to swing and shift the place of application of pressure progressively along the workpiece.

10. In a metal-working machine the combination of a machine frame comprising a base, supports upstanding from the base and a bridgemember extending transversely of the machine between the supports and above the base, a former support member depending from the bridge-member, a former secured above the base upon the lower end of the former support member, said former having a curved profiled face to receive a workpiece for shaping, which profiled face extends endlessly all around the former so that such face is in the form of a closed figure, an arm mounted on the frame to swing in a horizontal plane through a complete revolution around the former about a pivot pin located within the closed figure of the profiled face of the former, a fulcrum block in which the pivot pin is journalled, which block is mounted to slide horizontally between guide plates upon the frame in any direction to afford pivotal movement of the arm about different parallel axes, a flat table on the arm below the former, a shoe able to roll in a horizontal plane of movement on a workpiece placed against the former, which shoe rests on the table and is capable of being slid over it linearly and angularly in any direction, a main hydraulic piston and cylinder unit mounted on the arm to press the shoe against the workpiece on the former, said main piston and cylinder unit being provided with a roller nose to apply the pressure to the shoe which nose moves laterally as the arm swings thereby shifting the place of contact between roller nose and shoe along the shoe, and a pair of fulcrum-moving hydraulic piston and cylinder units mounted upon the machine frame with their axes lying substantially at right angles to one another in a horizontal plane, said fulcrum-moving piston and cylinder units being operatively connected to the fulcrum block for sliding it to various positions within the closed figure of the profiled face of the former to cause the arm, when pressure is applied to the workpiece by the main piston and cylinder unit and shoe, to swing and effect said lateral movement of the roller nose to shift the place of application of pressure to the workpiece by the shoe progressively along the workpiece.

UNITED STATES PATENTS References Cited in the file of thi patent, Number Name Date 1,714,083 Frank May 21, 1929 1,935,604 Abramson Nov. 21, 1933 2,142,443 Goin Jan. 3, 1939 2,148,748 Hardy Feb. 28, 1939 2,255,867 Wisckol Sept. 16, 1941 2,287,933 Green June 30, 1942 2,305,850 Drysdale Dec. 22, 1942 2,444,718 Bath July 6, 1948 2,501,241 Shaw Mar. 21, 1950

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