Overbending To Compensate For Springback Patents (Class 72/702)
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Patent number: 5461893Abstract: An apparatus and method is provided for the automated bending of continuous reels of metal strips, particularly for the bending of sharpened metal strip into steel rule dies. A sequence of steps is provided to perform a number of bends in the strip, at various positions on the strip, and of various magnitudes, in order to approximate the shape desired. Data containing the shape to be produced is introduced into a programmable computation and control system, which also contains data regarding the physical characteristics of the metal strip. An optical detection system is used to detect the shape produced at every step, and an electrical signal is fed back from the detection system into the computation and control system to compensate for any errors, particularly those errors caused by springback of the metal strip.Type: GrantFiled: May 28, 1993Date of Patent: October 31, 1995Assignee: CNC CorporationInventor: Arthur W. Tyler
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Patent number: 5454251Abstract: A manufacturing method of a shutter for a cartridge which is accommodating therein a recording medium includes the steps of punching out a plate-shaped metal material so as to provide a shutter of a developed shape having a pair of plate-shaped portions and a coupling portion for coupling the pair of plate-shaped portions, shaping the punched-out member in such a fashion that the pair of plate-shaped portions are opposed to each other across the coupling portion and that a spacing between free end sides of the pair of plate-shaped portions become narrower than a spacing of the pair of plate-shaped portions at its portion coupled by the coupling portion, and shaping the shaped member such that a spacing between free ends of the pair of plate-shaped portions of the member shaped by the second process become substantially equal to a spacing of the pair of plate-shaped portions at its portion coupled by the coupling member.Type: GrantFiled: January 26, 1994Date of Patent: October 3, 1995Assignee: Sony CorporationInventors: Takatsugu Funawatari, Daiki Kobayashi, Takashi Taguchi
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Patent number: 5341303Abstract: A method is disclosed for developing the contours of forming tools for fabricating metal members of complex shape such as wing skin and fuselage panels for aircraft. A computer simulation is performed of the age forming process on a geometrical representation of a member having the material properties of a desired metal member. The age forming process includes the steps of: a) overforming an unformed member in a tool having a contour of smaller curvature than the contour of the desired member; b) constraining the unformed member in the overformed condition; c) applying a thermal aging cycle to the member; d) cooling the constrained member following the thermal aging cycle; and e) releasing the constrained member from the condition imparted by step (b) and allowing it to spring back to a dimensionally stable condition which defines the desired member having a surface contour of complex shape.Type: GrantFiled: March 25, 1993Date of Patent: August 23, 1994Assignee: Avco CorporationInventors: Saeed D. Foroudastan, Mitchell C. Holman
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Patent number: 5297415Abstract: A method and apparatus for forming a length of tubing into a curved, unbalanced and non-uniform shape continuously bends the tubing and then changes the cross-sectional shape along the length of the tubing to eliminate springback and provide a stable part with shape retention The apparatus includes relatively movable upper and lower half die shoes A form post, a forming steel subassembly, a plurality of slides and driver posts are positioned on the shoes in juxtaposed relationship. A clamp holds a length of tubing against the form post. Movement of the die shoes towards each other shifts the slides to continuously bend the tube about the form post. After the bending operation, the cross-sectional shape of the tubing is changed from a generally circular shape towards an oval or generally rectangular shape. A pressure is applied to induce stresses which eliminate springback and provide a stable part.Type: GrantFiled: February 4, 1992Date of Patent: March 29, 1994Assignee: Steelcase Inc.Inventor: John L. Hendricks
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Patent number: 5284040Abstract: Tube bending apparatus comprising a lower support carrying a mandrel having a bending groove providing a bend axis, and an upper support mounted on the lower support for rotation about the bend axis and carrying a forming member for urging a tube between the mandrel and forming member into the bending groove on rotation of the upper support relative to the lower support. The upper support is adapted to be rotated relative to the lower support through a drive shaft arrangement extending downwardly from the lower support and coupled with a drive unit having an output coupling coaxial with the drive shaft and transverse to the axis of the drive motor of the drive unit. A stand supports the bending apparatus and drive unit relative to an underlying support surface during operation of the bending apparatus.Type: GrantFiled: December 9, 1992Date of Patent: February 8, 1994Assignee: Emerson Electric Co.Inventors: Valere H. J. Beelen, David L. Machovina
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Patent number: 5275031Abstract: A bend correction apparatus for bending a workpiece subject to springback, the apparatus having a pressure die for holding a workpiece, a radius die for providing a radius form about which the workpiece is bent, and a clamping die for engaging and bending the workpiece relative to the pressure die and about a portion of the radius die. A microprocessor moves the clamping die between a bend angle position in which the workpiece is bent about the radius die to a predetermined angle relative to the clamping die and a relieved position in which the clamping die is not bending the workpiece. A sensor, movable conjointly with the radius die, engages the workpiece in a springback position upon rotation of the radius die toward the workpiece and sends a signal to the microprocessor upon contact with the workpiece.Type: GrantFiled: June 5, 1992Date of Patent: January 4, 1994Assignee: Stark Manufacturing, Inc.Inventors: James A. Whiteside, Billy W. Morgan
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Patent number: 5168169Abstract: A method is disclosed for developing the contour of tools employed for forming aluminum alloy members exhibiting complex shapes. The members are precipitation, heat-treatable, aluminum alloys which are age formed. The resulting member is formed to the desired contour and, simultaneously, is heat treated to reduce residual stresses while improving its strength characteristics. The invention is particularly concerned with a new tool contour prediction method which is based upon the relationship, for a particular aluminum alloy, of the strain retained in a part after it has been subjected to an applied strain while constrained to a desired shape, then released after being heat treated in an autoclave or furnace.Type: GrantFiled: June 10, 1991Date of Patent: December 1, 1992Assignee: Avco CorporationInventors: Harold M. Brewer, Jr., Mitchell C. Holman
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Patent number: 5148693Abstract: A method for indirect detecting of folding angles (.beta.) of a metal sheet (4) during the folding by a folding machine (1) which has a punch (2), and a die (3) provided with a depressed seat (5) is disclosed. The folding angle (.beta.) is obtained by algebraic summing of an angle (.alpha.) formed by adjacent two walls (10, 10, 13, 13, 13a, 13b) of the punch (2) or the seat (5) and each angle (.alpha.1, .alpha.2) between a portion (7, 8, 8a) of the metal sheet (4) and the said wall. The angles (.alpha.1, .alpha.2) formed between the said portion (7, 8, 8a) and each wall (10, 13, 13a, 13b) are calculated by using the measurements of the distances (D1, D2, D3, D4) from the wall to the portion measured at desired two points on the wall. The distances are detected by a device such as differential transformers (18, 19, 20) and pneumatic gauges (50, 51, 52, 53, 54, 55) incorporated in the punch (2) or the die (3). The angle (.beta., .beta.1, .beta.Type: GrantFiled: October 29, 1991Date of Patent: September 22, 1992Assignee: Amada Company, LimitedInventors: Franco Sartorio, Bruno Nicoletta
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Patent number: 5099666Abstract: A method and a device for indirect detecting of folding angles (.beta.) of a metal sheet (4) during the folding by a folding machine (1) which has a punch (2), and a die (3) provided with a depressed seat (5) is disclosed. The folding angle (.beta.) is obtained by alebraic summing of an angle (.alpha.) formed by adjacent two walls (10, 10, 13, 13, 13a, 13b) of the punch (2) or the seat (5) and each angle (.alpha.1, .alpha.2) between a portion (7, 8, 8a) of the metal sheet (4) and the said wall. The angles (.alpha.1, .alpha.2) formed between the said portion (7, 8, 8a) and each wall (10, 13, 13a, 13b) are calculated by using the measurements of the distances (D1, D2, D3, D4) from the wall to the portion measured at desired two points on the wall. The distances are detected by a device such as differential transformers (18, 19, 20) and pneumatic gauges (50, 51, 52, 53, 54, 55) incorporated in the punch (2) or the die (3). The angle (.beta., .beta.1, .beta.Type: GrantFiled: November 14, 1990Date of Patent: March 31, 1992Assignee: Amada Company, LimitedInventors: Franco Sartorio, Bruno Nicoletta
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Patent number: 5094096Abstract: A method of bending round tubular metal stock for use in the manufacture of tubular frame furniture comprising the steps of first bending the stock to a shape close to the final angle and thereafter compressing the stock in a direction perpendicular to the plane of the bend so as to fractionally increase the stock diameter in the plane of the bend and reversely bend the stock so as to achieve the final angular relation.Type: GrantFiled: June 14, 1989Date of Patent: March 10, 1992Assignee: Chromcraft Furniture Corp.Inventor: Amuel E. Sheckells
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Patent number: 5050089Abstract: A tube bending die rotates to cause the tube to be bent over the outer periphery of the die and uses a drive which includes a transducer for measurement of the bending moment required for bending the tube. The bending moment signal is used in conjunction with a signal indicating the total amount of bend to control the number of degrees of bending and to overbend the tube an amount which is a function of the bending moment required to bend the tube, to compensate for springback. In its simplest form, the bending die is a rotating element, and the drive for rotating the die can include a force measuring link which can be converted into bending moment required for bending is used as a measured parameter for an equation which provides a signal indicating the amount of angular overbending needed to compensate for springback in an online, real time process.Type: GrantFiled: September 8, 1989Date of Patent: September 17, 1991Assignee: Regents of the University of MinnesotaInventors: Kim A. Stelson, Woon-Chung Wang
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Patent number: 5007264Abstract: In a method for the bending of workpieces by swivel bending jaws, the bent-off part is to assume a predetermined bending angle with respect to the workpiece, for this purpose, in a first bending operation, at least one corresponding leg is to be bent off from the workpiece by means of the swivel bending jaws. Then, the swivel bending jaws are released from the leg and a springback of the leg or the actual bending angle is determined by direct measurements and compared with a set bending angle. Subsequently, an agreement is established between set bending angle and actual bending angle by a renewed bending operation, by a bending-over.Type: GrantFiled: November 9, 1988Date of Patent: April 16, 1991Assignee: Feintool International HoldingInventor: Johannes Haack
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Patent number: 4989439Abstract: A device and method for taking to account the elasticity of materials during bending operations to cause the proper amount of overbending such that after springback and while at rest, the material assumes its intended shape.Type: GrantFiled: November 17, 1988Date of Patent: February 5, 1991Assignee: McDonnell Douglas CorporationInventors: Lee R. Ewert, Sumner B. Sargent, Walter Leodolter
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Patent number: 4979385Abstract: Process and apparatus for monitoring the backspringing of an elongated deformable elongated element while the element is bend by winding around a forming component. The element is clamped in a section located forward of the bend to be made. After the bend is made, the front section of the element remains clamped while the back section of the element is released. The backspringing value is determine by means of a sensor which makes a measurement on the back section of the element. The backspringing value is detected during a rotation of the element and the forming component around the axis of the bend by detecting when the back section reaches a predetermined position. This process makes it possible to continue bending of the element after detecting the backspringing value.Type: GrantFiled: April 21, 1989Date of Patent: December 25, 1990Assignee: Eaton Leonard Picot S.A.Inventors: Jean LaFrasse, Jean-Paul Chastan
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Patent number: 4947666Abstract: Apparatus for bending an elongate workpiece to a desired configuration includes a memory for storing information representative of the desired configuration and information representative of bending operations to be performed by a bending machine. A position sensor is used to scan a workpiece that has been bent using the bending machine, and thereby generate information representative of the actual configuration of the workpiece. The information representative of the actual configuration of the workpiece is compared with the information representative of the desired configuration and, in the event that there is a difference between the actual configuration and the desired configuration, and the difference is beyond a predetermined tolerance, the information representative of bending operations is modified in a manner such as to reduce the difference.Type: GrantFiled: September 16, 1988Date of Patent: August 14, 1990Assignee: The Boeing CompanyInventors: Albert L. Hametner, Larry L. Trammell
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Patent number: 4912957Abstract: A straightening press of the type wherein a workpiece is supported for deflection in a given direction by an anvil engageable with the workpiece. A reference spring is supported for deflection with the reference spring supports being serially interconnected with the anvil. In a preferred embodiment, a floating bridge carries the anvil and reference spring supports. Deflecting force applied to the reference spring, as by a ram, is transmitted to the workpiece via the floating bridge. A change in the differential displacement of the ram and floating bridge is detected to determine the onset of plastic deformation of the workpiece.Type: GrantFiled: April 28, 1989Date of Patent: April 3, 1990Assignee: Dayton Rogers Manufacturing CompanyInventors: Paul S. Petersen, Virgil C. Hed
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Patent number: 4864509Abstract: A method and related system for operating a computer controlled press brake system to form a requested bend angle in a workpiece are described. According to the disclosed method, values corresponding to geometrical characteristics of the press brake and a first workpiece are stored, as is a value for the requested bend angle. A ram of the press is operated in a first direction, relative to the die, to a first selected position to bend the first workpiece and to hold the first workpiece to a restrained bend angle. The ram is thereafter operated in a second direction to release the first workpiece to an unrestrained bend angle. The difference between the restrained and unrestrained bend agles of the first workpiece is calculated. Using the values for geometrical characteristics and the requested bend angle, a correction factor is calculated. In accordance with the correction factor, the unrestrained and requested bend angles, the ram is set to travel to a corrected position.Type: GrantFiled: September 29, 1987Date of Patent: September 5, 1989Assignee: The Boeing CompanyInventors: Gordon R. Somerville, D. Bruce Thomas
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Patent number: 4845992Abstract: The vane adjusting machine for increasing or decreasing the flow through a turbine nozzle includes a bending tool for attachment to a wrist of a robot arm whose operation and function is controlled by computer hardware and software. The bending tool preferably includes a floating head assembly and an interchangeable jaw sub-assembly. In operation, a turbine nozzle is subjected to an airflow test. Subsequently, the turbine nozzle is mounted on a rotatable work surface and a first vane is initialized to a bending station location. The bending tool controlled by the computer then locates and bends the first vane to a desired orientation based on the airflow test results. On completion of the bending of the first vane, the bending tool is removed from proximity with the first vane, and the computer controls the rotation of the worktable to position a second vane at the bending station location.Type: GrantFiled: December 22, 1987Date of Patent: July 11, 1989Inventor: Michael J. Dean
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Patent number: 4824632Abstract: A straightening device (16) for bent fuel assembly alignment pins (12) in an upper core plate (10) comprises elongated mast (22) having an upper and lower portion, bail (25) secured to the upper portion and cross member (28) secured to the lower portion. At one end of the cross member (28) is attached pin straightening assembly (19), the other end having counterweight (31) to assure a horizontal orientation of the cross member (28). Pin straightening assembly (19) is further comprised of housing (37) having wedge-shaped adjustable shim (61) connected to its top surface, the housing (37) secured to the cross member (28) by baseplate (34). Four axially compressible and laterally deformable compression springs (41) are connected between baseplate (34) and housing (37) to provide angular and translational compliance for housing (37).Type: GrantFiled: December 31, 1987Date of Patent: April 25, 1989Assignee: Westinghouse Electric Corp.Inventors: Robert E. Meuschke, Edward P. Shields
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Patent number: 4819467Abstract: A computer-based control for a press brake of the type having a ram for bending a sheet metal workpiece to a desired bend angle. The control incorporates a teach mode which collects ram force and position data during the bending of one or more test workpieces and calculates from the force and position data parameters representative of the ram reversal position necessary to produce the desired bend angle. The control also incorporates a bend mode for bending a production workpiece to the desired bend angle wherein force and position data is collected during the bending of the production workpiece and is used in conjunction with the parameters calculated during the bending of the test workpieces during the teach mode to calculate the exact position of ram reversal necessary to produce the desired bend angle in the production workpiece. The control also incorporates correction of the position of ram reversal to account for ram overshoot during the bend mode.Type: GrantFiled: September 17, 1986Date of Patent: April 11, 1989Assignee: Cincinnati IncorporatedInventors: Raymond J. Graf, Scott D. Tucker
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Patent number: 4813255Abstract: An automatic lead sensing and fine-forming system is disclosed for preparing the leads of electronic components so that they are ready to be inserted by robots into holes on printed circuit boards. The positions of the lead tips and the positions of the holes are sensed and compared to determine if any leads need to be bent. These leads are then bent and the force on the leads and their displacement are sensed and recorded during the process. The data recorded is then used for subsequent bendings, where necessary, for bending the leads to the target locations so that all the leads fit simultaneously into the holes. To simplify image processing, the lead tips are illuminated by light originating from substantially isotropic directions from locations substantially coplanar with the region of the lead tips.Type: GrantFiled: August 26, 1987Date of Patent: March 21, 1989Assignee: Hewlett-Packard CompanyInventors: John Birk, Heinz Breu, William Gong, Charles C. Morehouse, Sidney Liebes, Jr.
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Patent number: 4802357Abstract: An apparatus and a method for bending a workpiece to a predetermined angle in a brake press and automatically compensating for springback of the workpiece which has a sensing device, biased relative the workpiece, for detecting a neutral position of the workpiece corresponding to the cessation of springback motion and generating a signal in response thereto, and a device, responsive to the signal, for measuring the linear distance of springback, and for calculating an amount of overbend required to compensate for springback based on said measured linear distance of springback and the physical geometry of the workpiece. Preferably, the sensing devcie having a linear variable differential transformer having a core rod biased toward the workpiece and in opposition to the punch member of the brakepress.Type: GrantFiled: May 28, 1987Date of Patent: February 7, 1989Assignee: The Boeing CompanyInventor: Everett E. Jones
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Patent number: 4797831Abstract: An electronic control system for operating the hydraulic cylinders associated with a press brake wherein independent control of each of the hydraulic cylinders is achieved to insure that the cylinders track against a fixed reference to insure more accurate forming of the workpiece. The cylinder tracking is under computer control which also establishes a creep speed slower than the normal forming speed near the point of ram reversal. A plurality of press brake may be operated simultaneously from the same tracking reference.Type: GrantFiled: November 18, 1986Date of Patent: January 10, 1989Assignee: Cincinnati IncorporatedInventors: Paul A. Dressing, John L. Macdonald
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Patent number: 4744302Abstract: In a mobile track working machine comprising a frame mounted for mobility on the track: a mechanism for bending the track rail section ends comprises a carrier frame vertically adjustably mounted on the machine frame above a respective track rail and having respective end regions spaced from each other in the direction of the track rail, a respective hydraulically operable and vertically adjustable thrust element mounted in a respective end region of the carrier frame for engagement with the running face of the track rail, an intermediate carrier transversely movably mounted on the carrier frame, and a rail lifting hook device supported centrally between the thrust elements on the intermediate carrier for engagement with the track rail, the hook device including two lifting hooks arranged symmetrically with respect to the vertical plane of symmetry of the rail, a respective pivot having an axis extending in the direction of the track rail and mounting a respective lifting hook for pivoting into a rail engaginType: GrantFiled: May 1, 1986Date of Patent: May 17, 1988Assignee: Franz Plasser Bahnbaumaschinen-IndustriegesellschaftInventors: Josef Theurer, Friedrich Peitl
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Patent number: 4702097Abstract: In order to form materials (18) in a cold state automatically and reproduceably a bending machine (10) is proposed, comprising at least two bending carriages (14, 16), which interact with the material so that one of the bending carriages (14 or 16) constantly holds the material (18) immoveable when the other bending carriage (16 or 14) is bending the material (12) or is being moved along it.Type: GrantFiled: March 14, 1986Date of Patent: October 27, 1987Inventor: Helmut Zahlaus
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Patent number: 4640113Abstract: A press has an upper table carrying a punch and a lower table bearing a tool-carrier. A jack for compensating the deflection inherent in the bending process is fitted in the lower table. The bending device enables the bending angle obtained in the workpiece to be monitored continuously. The bending device includes a series of paired measuring rods, circular in section and longitudinally machined to provide a flat surface for the lower surface of the workpiece to rest on, associated with devices for measuring the rotational angle of the measuring rods, and a control device connected to the rotational angle measuring device, to a device for controlling the jacks that actuate the punch and to the actuating device of the jack for compensating the deflection. A very accurate and constant bending angle is obtained throughout the length of the workpiece. The bending process is automatic and continuous once the operator has fed in the required bending angle.Type: GrantFiled: February 4, 1985Date of Patent: February 3, 1987Assignee: Beyeler Machines, S.A.Inventors: Willem Dieperink, Arend Vruggink
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Patent number: 4627255Abstract: In a bending machine, metal strip (42) is bent by a sequence of steps including longitudinal advance of the strip (42) alternating with bending of the strip by a movable tool (18) which engages and deflects the strip when the latter is restrained against longitudinal movement. Provision is made for checking or inspecting the permanent angular deformation of each bend applied to the strip, to take account of the tendency of the metal strip to spring back after bending. Compensation for spring-back is achieved by use of a previously described characteristic relating displacement of the bending tool to the resultant permanent angle of bend applied to the strip. Further compensation is provided to remove an error which can arise if the bending tool is movable along a line of action spaced from the point of bending of the strip by an amount greater than the incremental advance of the strip.Type: GrantFiled: February 1, 1984Date of Patent: December 9, 1986Assignee: USM CorporationInventors: John R. Archer, Michael J. Kellaway, Douglas S. MacArthur
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Patent number: 4552002Abstract: An apparatus for bending a plate utilizing a bending punch and a die into which the bending punch penetrates to a greater or lesser extent depending on the bending angle .alpha.. The magnitude and variation of the bending force required during deformation of the plate unit are determined and utilized to determine the depth h of punch penetration.Type: GrantFiled: February 14, 1985Date of Patent: November 12, 1985Assignee: Hammerle, AGInventors: Eduard Haenni, Theo Frei
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Patent number: 4531391Abstract: Deviations from desired shape of plasticly deformable objects are corrected within narrow tolerances by a method wherein the real shape of the object is sensed, whereupon the deviation from the desired shape is determined and a correction length corresponding to the deviation is defined, after which the object in a straightening operation is subjected to a shape correction corresponding to the correction length. At least one measurement transmitter (4) is disposed to sense the real shape of the object (2) and deliver a corresponding output signal which is fed to a unit (6,8,9) for comparison with information about the desired shape of the object stored in the unit for determining the deviation, the unit delivering an output signal defining a correction length corresponding to the deviation, the output signal controlling a straightening device (12,14,16,18,20,22,24) to carry out a correction of the shape of the object corresponding to the correction length.Type: GrantFiled: March 24, 1982Date of Patent: July 30, 1985Assignee: AB Thorns Mekaniska VerkstadInventor: Guy R. Engman
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Patent number: 4511976Abstract: An electronic control system for use with hydraulic press brakes to provide compensation for material spring back to accurately produce a desired bend angle in the work piece. The ram force and flank angle of the work piece are monitored during the forming cycle to calculate the theoretical unloading curve of the work piece. Intersection of the plastic portion of the work piece force-angle curve with the theoretical unloading curve provides a calculated point of ram reversal resulting in the desired bend angle. The system compensates for changes in springback resulting from changes in material properties from one work piece to the next.Type: GrantFiled: July 6, 1982Date of Patent: April 16, 1985Assignee: Cincinnati IncorporatedInventor: Raymond J. Graf
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Patent number: 4488423Abstract: A machine for straightening an elongated workpiece has a plurality of coacting tools which include first and second sets of tools arranged in alternate series along a fixed longitudinal axis to engage successive longitudinally spaced portions of a workpiece positioned therebetween with its longitudinal center line generally aligned with a longitudinal axis. A cam operated lever system simultaneously reciprocates the tools of the first and second sets in opposite transverse directions relative to the longitudinal axis and each other to alternately displace portions of the center line of the workpiece to one and the opposite side of the longitudinal axis. A mechanism is provided to vary the magnitude of reciprocating lever movement to vary center line displacement between a position of maximum displacement and a position wherein workpiece portions are substantially longitudinally aligned.Type: GrantFiled: May 31, 1983Date of Patent: December 18, 1984Assignee: Bertolette Machines, Inc.Inventors: Burtram I. Newell, Reed Bertolette, Bruce C. Fogarty
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Patent number: 4424727Abstract: A method for making a metal stamping die suitable for use in forming sheet metal reflectors for photographic use. The structure of the metal stamping die is made in the manner of the method to compensate for spring-back characteristics of a material used to form a reflector by first constructing a test die which has a predetermined shape related to the desired reflector shape. A comparison is then made between a test workpiece made with the test die and the desired reflector shape to determine the die shape that produces a corresponding portion of the reflector shape. Finally, another die is constructed by shaping it in accordance with the comparison to obtain a final die shape that will acceptably produce the desired reflector shape.Type: GrantFiled: September 15, 1980Date of Patent: January 10, 1984Assignee: Polaroid CorporationInventor: John J. Mader
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Method and apparatus for bending the overlapping edge portions of a metal shield around a cable core
Patent number: 4377908Abstract: Controlling the bending of an overlapping edge portion of a metal shield of a cable core by supporting one side of an edge portion at a position along its feed path and applying pressure against the edge portion immediately downstream of and in a direction opposite to the support. Bending of the edge portion occurs immediately it has passed the support while the support dampers resiliency in the edge portion to prevent or lessen springback. Apparatus for bending is placed immediately upstream of the overlapping die and preferably includes means to vary the applied pressure. Hence, the desired orientation of the bent edge portion is obtainable by varying the pressure dependent upon the actual orientation as the overlapped shield leaves the die.Type: GrantFiled: May 18, 1981Date of Patent: March 29, 1983Assignee: Northern Telecom LimitedInventor: Ali Pan -
Patent number: 4187711Abstract: A method of manufacturing a high fin density heat dissipator is disclosed in which the dissipator is extruded through a die in a partially cylindrical shape with the elongated fins arranged on the base and extending radially therefrom. The extruded dissipator is straightened under tensile and bumping forces in a manner such that the base assumes a planar shape and the fins become substantially parallel to each other. Apparatus for straightening the extruded dissipator and a die for extruding the same are illustrated and described.Type: GrantFiled: July 24, 1978Date of Patent: February 12, 1980Assignee: Wakefield Engineering, Inc.Inventors: Ronald B. Lavochkin, Thomas D. Coe
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Patent number: 4125929Abstract: A method employing a deformable metallic element is disclosed particularly characterized in that the element is formed of a hard resilient metal which undergoes work hardening when it is deformed beyond the elastic limit thereof. The element is made in the form of a relatively thin walled tubular member convoluted in longitudinal cross section. Upon axial compression the element undergoes a first period of resilient deformation during which the compressive force increases substantially linearly followed by a second period of plastic deformation during which the compressive force remains constant. The method is suited to imposing a substantially constant predetermined preload on a pair of opposed members.The element of the present invention is particularly useful as a load member to create a predetermined load on a part which it is desired to maintain under a predetermined constant load.Type: GrantFiled: September 30, 1977Date of Patent: November 21, 1978Assignee: Temper CorporationInventor: John E. Rode
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Patent number: 4122697Abstract: A means and method is provided for reducing radius expansion of bent, elongated materials due to "spring-back" occurring after the material is released from the bender clamps of a hot bending apparatus, wherein the longitudinal axis of the unbent portion of the material is displaced by a small angle from a perpendicular to a line running through the center of the bend and the bender heating means.Type: GrantFiled: July 29, 1976Date of Patent: October 31, 1978Assignee: Daiichi Koshuha Kogya Kabushiki KaishaInventors: Susumu Hanyo, Jousuke Yamaguchi, Yoshiyuki Morishita, Itoshi Noguchi
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Patent number: 4078407Abstract: In order to accurately control a process in which a structural component of ductile material is subjected to a change in shape by the application of a progressively increasing deformation force while measuring the resulting deformation, the measured deformation is employed to derive a representation of a nominal deformation force which varies as a predetermined function of deformation over a selected deformation range, the representation is compared with the applied deformation force, and the application of the deformation force is terminated upon arriving at a deformation amount for which the applied deformation force coincides in value with the nominal deformation force.Type: GrantFiled: March 25, 1976Date of Patent: March 14, 1978Assignee: Meyer, Roth & Pastor Maschinenfabrik GmbHInventor: Gunter Ditges
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Patent number: 4025044Abstract: A method of making a resilient double C-shaped clip for securing a rail on a support, wherein in advance of the heat treatment the ends adapted to cooperate with the support and with the foot of the rail are bent towards one another in the direction of the fastening force to such an extend that they are offset with respect with one another over a certain distance in relation to their position when the ready clip is free of load and wherein after the heat treatment the clip is subjected to a series of permanent deformations, each effected by imposing a permanent deformation force on one end of the clip while the other end is held in fixed position, such that upon a continued deformation there would be no increase or only a very small increase of the load, and the clip being relieved of load after each deformation.Type: GrantFiled: January 27, 1975Date of Patent: May 24, 1977Assignee: B.V. Schroefboutenfabriek v.h.Everts en van der WeijdenInventor: Lodewijk Goderbauer
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Patent number: 3955389Abstract: A sensing structure and control system therefor suitable for use in a numerically controlled roll forming machine are disclosed. The sensing structure includes a support arrangement for mounting a sensor in a position such that a work part exiting from contour forming rollers passes through the structure. The support arrangement is formed such that the sensor is free to move as exiting part contours change. As exiting part contours change, the change in position of the sensor varies the position of a rotary variable-differential transformer (RVDTs). The output from the RVDT is compared with signals related to the desired curvature of the part and the result of the comparison is used to modify the control signals applied to the numerically controlled contour forming machine to provide compensation for part springback. Further, a manual signal modifying mechanism is provided for inserting modifying signals also adapted to modify the control signals to compensate for part springback.Type: GrantFiled: April 21, 1975Date of Patent: May 11, 1976Assignee: The Boeing CompanyInventor: Gene B. Foster
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Patent number: 3948076Abstract: Method and apparatus for automatically straightening elongated and at least partly rotationally symmetrical workpieces by applying a sequence of straightening strokes to a workpiece at each of a plurality of straightening stations to counteract a deformation until the measured instantaneous values of the deformation fall within a predetermined deformation tolerance. The depth of the straightening strokes is determined by the difference between the measured instantaneous values of the deformation and the mean of the maximum and minimum values of the deformation.Type: GrantFiled: September 17, 1974Date of Patent: April 6, 1976Assignee: Eitel KG., WerkzeugmaschinenfabrikInventors: Hans-Georg Eitel, Waldemar Morlock, Dieter Ruf
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Patent number: 3943746Abstract: Method and apparatus for automatically straightening elongated and at least partly rotationally symmetrical workpieces by applying a sequence of straightening strokes to a workpiece at one straightening station to counteract a deformation until the measured instantaneous values of the deformation fall within a predetermined deformation tolerance. The depth of the straightening strokes is determined by the difference between the measured instantaneous values of the deformation and the mean of the maximum and minimum values of the deformation.Type: GrantFiled: September 17, 1974Date of Patent: March 16, 1976Assignee: Eitel KG., WerkzeugmaschinenfabrikInventors: Hans-Georg Eitel, Waldemar Morlock, Dieter Ruf