US3197990A

US3197990A - Metal forming device

Info

Publication number: US3197990A
Application number: US244167A
Authority: US
Inventors: Thomas A Stubblefield
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-12-12
Filing date: 1962-12-12
Publication date: 1965-08-03
Anticipated expiration: 1982-08-03

Description

3, 1955 T. A. STUBBLEFIELD 3,197,990

METAL FORMING DEVICE Filed D66. 12, 1962 3 Sheets-Sheet INVENTOR. Grassy/5L0 Aug. 3, 1965 T. A. STUBBLEFIELD 3,197,990

METAL FORMING DEVICE Filed Dec. 12, 1962 3 Sheets-Sheet 2 12 0/7461! STUEEEF/ELO 1965 T. A. STUBBLEFIELD 3,197,990

METAL FORMING DEVICE 3 Sheets-Sheet 3 Filed Dec. 12 1962 INVENTOR. flan/45A. 6'705545F/5L0 United States Patent 3,197,939 METAL FORMING DEVICE Thomas A. Stubhlefield, Vista, (Talih, assignor of onethird to James F. Brooks, Garden Grove, Calif and one-third to John H. Hancock, La Habra, (Ialif.

Filed Dec. 12, 1962, Ser. No. 244,167 11 Claims. (Cl. 72-131) This invention pertains to a forming device, and more particularly to a machine for bending spring steel strips into an undulant contour.

One important field of use for the device of this invention is in the manufacture of suspension strips for hanging draperies. At the present time, an increasing practice is to hang draperies by means of an undulantly formed strip of spring steel fitted through a hem formed in the end of the drapery material. This avoids the time and effort required to produce sewn pleats in the drapery material, and provides an improved pleasing appearance to the draperies. Many problems have been encountered, however, in the production of the spring steel strips used in supporting the draperies. In the past the production has been relatively slow and expensive, and has not resulted in a product formed to the accuracy desired. There have been limitations on the thickness and-hardness of the material that can be formed, and breakage of parts has occurred too frequently. Furthermore the lengths of contoured spring steel stock have been ditlicult to handle and to package for shipment and use.

The present invention provides an improved means of forming the ribbon of spring steel used for draperies, producing the parts more rapidly and accurately than in the past. This is accomplished through the provision of sets of opposed rollers through which a strip of material is pushed. Consequently the workpiece, despite the fact that it is in strip form, is not intension as it is contoured, but is forced through the forming rollers under compression. The rollers are suitably indexed so that the desired contour is imparted to the material, forming two loops of material on opposite sides of the center. An automatic feeding arrangement for the material punches properly spaced holes through it which. are used for positioning the strip and for forcing it through the roller assembly in predetermined lengths. The apertures punched in the material later are used as a means for suspending it as the product is used.

, It is an object of this invention to provide an improved bending device.

Another object of this invention is to provide a better means for producing metal strips in an undulant contour.

A further object of this invention is to form drapery suspension parts more rapidly, with greater precision and with less cost than in the past.

An additional object of this invention is to form pleated metal strips of materials harder and thicker than possible with previous forming techniques.

These and other objects will become apparent from the following detailed description taken in connection with the accompanying drawing in which:

FIG. 1 is a plan view of the forming arrangement of this invention,

FIG. 2 is a fragmentary perspective view of a com-,

pleted part formed in accordance with this invention,

FIG. 3 is an enlarged transverse sectional view taken along line 33 of FIG. 1,

FIG. 4 is a sectional view taken along line4-4 of FIG. 3 showing the arrangement for driving and holding the workpiece,

FIG. 5 is a fragmentary sectional view taken along line 6-6 of FIG. 3 illustrating the release for one of the positioning pins,

ice

FIG. 6 is a sectional view taken along line 66 of FIG. 3 showing the gear and rack drive arrangement,

FIG. 7 is a sectional view taken along line 55 of FIG. 3 illustrating the mounting of the forming rollers,

FIG. 8 is a fragmentary perspective view of the roller assemblies,

FIG. 9 is a schematic plan view of the roller assemblies in one position of adjustment,

FIG. 10 is a schematic view similar to FIG. 9 with the roller assemblies in a second position,

FIG. 11 is a schematic view of the roller assemblies in a third position,

FIG. 12 is an enlarged sectional view taken along line 1212 of FIG. 3 showing the arrangement for indexing the roller assemblies; and

FIG. 13 is an elevational view of the mounting means for the takeup drum.

With reference to the drawing, the overall arrangement of the device of this invention may be seen by reference to FIG. 1. A strip 1 of relatively narrow spring steel material is carried on a rotatable spool 2 from which it is fed into the machine 3 for forming. Before entering the machine the workpiece 1 passes through a light spring guide 4 that holds the material in a slightly looped configuration. This is to provide adequate available stock for the operation of the machine without imparting a shock load on the strip 1, and avoids breakage of the material. After being formed the contoured part passes through opposed guide sections 5 and 6 to be wound on a takeup drum 7. In the machine the strip 1 is given the undulant or pleated contour indicated in FIG. 2. The machine 3 is operated by a suitable source of power that through belt 9 drives pulley 10 which in turn rotates a crank 11. The latter member through connecting rod 12 imparts reciprocating movements to a ram 13. The ram moves toward and away from a fixed platen 14.

The workpiece 1 passes through the platen in guide slots that direct it substantially at right angles to the line of movement of the ram 13. With reference to FIG. 4, it may be seen that as the ram 13 approaches the end of its stroke adjacent the platen, it forces a plunger 16 against the exposed adjacent surface of the metal strip 1 at the entry of the machine 3. Beneath the plunger is compression spring 17 so that the member 16 resiliently grips the workpiece 1 and holds it against the adjacent opposed surface of the platen.

Upon the gripping of the workpiece by the plunger 16 the continued movement of the ram 13 causes a punch 18 to be forced through the workpiece and into a corresponding die opening 19 in the platen. This forms a small aperture 20 in the mid-portion of the workpiece 1.

The means for feeding the workpiece through the machine includes a rod 22 one end of which through pin 23 is attached to the ram 13, while the opposite end by pin 24 connects to a crank 25. The latter member is keyed to a gear 26. Hence, it can be seen that reciprocation of the rain will cause rotating movement of the gear 26 as the rod 22 moves the crank 25 back and forth. The gear 26 meshes with a rack 27 which is slidable within appropriate recesses formed in the platen 14. As a result the rack is movable across the platen parallel to the guide slots for the workpiece 1.

Pivotally carried by means of pin 28 at the lower portion of the rack 27 is a drive member 29 which is biased downwardly by means of a spring 30. A projection 31 at the lower edge of the drive member 29 is adapted to enter one of the openings 20 formed by the punch 18' and the workpiece 1. It can be seen, therefore, that with the projection 31 received in an opening 20 movement of the ram 13 away from the platen 14 will cause gear 26 to move the rack 27 to the right as machine is seen in FIG. 4. This in turn will cause the drive member to move the workpiece 1 along with the rack in the same direction.

Upon reverse movement of the rack 27 as the ram then next advances toward the platen, the drive member 29 automatically will release the part and return to its original position for engagement with the next aperture 2%. This occurs because the projection 31 is beveled on the lower left surface and hence will slide out of the aperture as the rack returns. The opposite side of the projection 31 is perpendicular with respect to the workpiece so that it can enter the aperture 20 and cause the driving movement.

The apertures 20 are used also for positioning and holding the workpiece in the machine at various times in the cycle of operation. During return movement of the rack and drive member, the workpiece 1 is kept stationary by means of a pin 33 that enters the next aperture 20 as the workpiece is advanced through its increment of travel. The pin 33 shown in particular in FIG. 5 as well as FIG. 4 is constructed as a T-shaped element having a base portion 34 that is movable within opposed slots 35 in the platen structure. A compression spring 36 biases the pin 33 toward the workpiece. However, the pin 33 can be held in a retracted position away from the strip 1 by a detent 38 on a pivotal arm 39 which holds the end of a bell crank 40 in a raised position. The opposite end of bell crank 46 is bifurcated and engages the base portion 34 of the pin 33. Hence, while so engaged by the detent 38, the bell crank 40 holds the pin 33 away from the workpiece 1. This allows the drive element 29 to engage the workpiece so that movement of the rack will advance the strip through the machine. However, as the ram moves away from the platen in advancing the rack 27 and the drive member 29, a cam 42 carried by the ram engages a beveled surface 43 on the end of arm 39. This pivots the arm 39 outwardly so that the detent 38 releases the end of bell crank 40. As a result, the pin 33 is released and the spring 36 advances it toward the workpiece 1. As soon as the next aperture 20 is in registry with the location of pin 33 it will enter the opening 20, positioning and holding the workpiece. Upon the reverse movement of the rack, therefore, the workpiece 1 is held and the drive member 29 will have no tendency to cause the workpiece to move in the wrong direction.

As the ram 13 then again approaches the platen, the end of cam element 42 is brought into engagement with the outer end of the bell crank 40. Continued movement of the ram, therefore, causes the actuation 42 to move the bell crank 40 to the position where the detent 38 again engages and holds the bell crank. Thus as the ram ap roaches the end of its stroke toward the platen, the pin 33 releases the work and the drive member 29 makes its engagement in the aperture 20.

At the right hand end of the machine as illustrated there is an additional holding means for the workpiece provided by an indexing pin 45 biased by compression spring 46. Asa result, the pin '45 which moves with ram 13 is caused to enter one of the apertures 20 upon conclusion of the stroke of the actuating member 29. It is obvious, of course, that the location of the punch and indexing pins are correlated with the stroke of the rack so that the workpiece can be properly engaged by these elements.

It should be noted that the positioning pins 33 and 45 are removed from the workpiece prior to advancement of drive member 29 by the rack. This occurs because of the clearance provided at the slot'47 where the pin 23 interconnects the rod 22 and the ram. The ram moves away from the platen the length of the slot 47 before the rod causes the gear 26 to rotate and slide the rack forwardly. This is sufficient free travel to permit the indexing pins to move out of the openings 20 so that the strip 1 no longer is held against movement.

The actual forming takes place in a pair of

roller assemblies

48 and 49 shown in perspective in FIG. 8. These assemblies include individual

parallel rollers

50, 51,

Cit

52 and 53. The

rollers

50 and 51 are rotatably carried on a support 54, while a similar support 55 carries the other pair of rollers. These roller supports are in turn mounted on rotatable shafts 56 and 57 which are coupled together by meshing gears 58 and 59. The shafts have their axes parallel to the axes of the rollers, and each shaft axis will intersect the mid-point between the two rollers it carries. It can be seen, therefore, that by appropriate rotation of the gears the roller supports can be positioned to -vary therelationship of

theroller assemblies

48 and 49.

In imparting the undulant contour to the workpiece 1 the roller assemblies are indexed to different positions during successive strokes of the machine. This may be understood best by reference to the schematic illustrations of FIGS. 9, l0, and 11. In the position of FIG. 9 the

rollers

50 and 51 are located so that a line interconnecting their axis would be substantially parallel to the path of the workpiece 1. The other two

rollers

52 and 53 are positioned at degrees to the first pair. This provides a path for the workpiece across the top of roller 52 and beneath the peripheries of

rollers

50 and 51. The roller 53 is inoperative for this position of the roller assembly. The

rollers

50, 51, and 52 cooperate, therefore, to provide a curved path for the workpiece. When the workpiece is shoved through this passageway by the drive mechanism the rollers impart a smooth circular contour to the workpiece as shown in FIG. 9.

The machine then is returned by advancement of the ram toward the platen and the

roller assemblies

48 and 49 are indexed to the position of FIG. 10. The exact means for accomplishing this is explained below. For this indexing movement the roller assembly 48 is rotated about the axis of shaft 56 through a 90 degree are in the counterclockwise direction. At the same time, assembly 49 rotates clockwise about its shaft 57 through an identical angle. This brings

rollers

52 and 53 to a position of parallelism with the incoming strip 1 while the other pair now is normal to it. This places roller 50 in between the pair of

rollers

52 and 53 of the assembly 49. Hence, as the workpiece again is forced through the rollers it is given a curvature as it is passed beneath roller 59 and above

rollers

52 and 53. This will provide a curvature similar to that given the workpiece when the roller assemblies were in the position of FIG. 9. However, since the roller assemblies have been effectively reversed the workpiece is bent in the opposite direction; Consequently, while the workpiece was forced to the side of roller assembly 49 during the first forming stroke, it is moved to the opposite side on the next. Hence, the part whips back andforth as it leaves the forming rollers. For each subsequent stroke the roller assemblies again are rotated through their 90 degree arcs. Of course, as the cycle continues the roller assemblies will assume the position of FIG. 11 where they are reversed from the position of FIG. 9. That is to say, the roller 53 will be disposed between the

rollers

50 and 51 which will be in turn reversed degrees from the position of FIG. 9. This Is of no consequence, however, because as far as the workpiece is concerned the effect is exactly the same as that in FIG. 9. Thus the pairs of rollers assume four different positions during a complete revolution of the roller assemblies, but provide two difierent configurations for the forming of the workpiece 1. V

The roller assemblies are driven to their various positions by means of a notched disc 62 that is rotatable with the shaft 57. This disc includes four equally spaced radial recesses 63 in its periphery which are engaged by spring loaded pawl 64. The pawl is carried by an arm 65 which is rotatable about the axis of the shaft 57. The end of arm 65 connects by pin 66 to a rod 67. The

latter element through pin '58 received in slot 69 is con-- 7 nected to-the ram 13.

D crank 65 in a counterclockwise direction as the parts are seen in FIG. 12. This causes the pawl 64 to index from one notch 63 to the next. Movement of the ram toward the platen, however, causes the crank to move in a clockwise direction, which through the pawl 64 in the notch 63 drives disc 62 likewise in the clockwise direction. Thus as the ram approaches the platen the

roller assemblies

48 and 49 are indexed to their next succeeding position. During the movement of the roller assemblies, the workpiece is prevented from movement by the pressure pad 16 and the indexing pin 45. However, the workpiece is not formed during the repositioningof the roller assemblies, the contouring being accomplished subsequently as the work is pushed through the rollers.

The roller assemblies are maintained in their indexed positions by means of a slidable stop 70 biased against the periphery of the disc 62 by compression spring 71. The end of stop 7% is adapted to enter the slots 63 for holding the disc locked against movement. Stop 76 can be released by means of an arm 72 carried by a post 73 that projects forwardly of the ram 13, and can pass through opening 74 in the stop. Arm 72 includes an inclined cam surface 75 that reacts against cam surface 76 on the stop 70 as the ram is moved toward the platen. Upon reverse movement ofthe ram, however, flat surface 77 of arm 73 engages the edge of the apertures of stop 70 and the arm merely rotates about mounting pin 78,

thereby allowing it to pass through opening 74 without disturbing the position of the stop 70. The arm is spring pressed against abutment 79 so that movement about pin 78 in the opposite direction is precluded. The clearance at slot 69 where rod 67 connects to the ram assures that the stop is removed from slot 63 prior to the time the pawl 64 commences to rotate plate 62.

After passing the

form roll assemblies

48 and 49 the contoured part'is fed onto flat horizontal plate 80 between the guides 5 and 6 to the takeup drum 7. The guides 5 and 6 are spaced apart adjacent the forming rolls which allows the workpiece to move back and forth as the different contours are imparted to it. These guides preferably are resilient in nature, so that as the pleated strip strikes one of the guides it rebounds toward the other. This conserves energy and allows the part to whip back and forth without being subjected to excessive forces. The guides may be adjustable to control the amount of movement allowed the part. This in turn assists in assuring that the loops in the part are of the proper size and contour, and that the openings 2% are in alignment.

The takeup drum is mounted on a threaded shaft 82 which passes through a threaded aperture at the axis of the drum. The drum is slowly rotated in increments by means of a drive crank 83 pivotal about pin 84 and reciprocated back and forth by means of rod 85. The drive member 83 includes a spring loaded pawl engageable with the toothed periphery of flange 86. The latter element connects to toggle links 87 and 38 that are mounted between the movable ram and fixed structure of the machine 3. As a result each stroke of the ram causes incremental rotational movement of the disc 86 which in turn causes the drum 7 to turn on the. shaft 82. The use of links 87 and 88 reduces the initial velocity of movement of rod 85 and minimizes shock loads.

As a consequence of the rotational movement of the drum on shaft 32, the formed workpiece is taken up on the drum and is wound on the drum in a helical fashion. The lead of the screw thread on shaft 82 is correlated with the drum diameter and the amount of rotational movement so that the drum moves appropriately in an axial direction to effect the helical winding. The drum drive may be adjusted to put tension on the part if desired. This tension can be made exactly the necessary amount to stretch out the part slightly as may be needed to locate the apertures 2i) in precise alignment at the center of the completed unit between the two outwardly projecting loops on either side of each such aperture;

This is the desired location for these openings which later are used in connection with the mounting arrangement for the drapery held on the completed part.

From the foregoing it can be seen that I have provided an improved forming arrangement in which .a strip of material is contoured by being pushed through the passageway defined by the forming rollers. The forming takes place between three adjacent rollers, while for convenient automatic operation four are included in the machine, indexed appropriately to vary the forming passageway. The invention produces parts rapidly and accurately imparting sufiicient bending to cause the central poritions of the part to be in actualcontact when in the free position. Moreover, the invention allows the use of both thicker and harder materials than has been possible in the past.

The foregoing detailed description is to be clearly understood as given by way of illustration and example only. The spirit and scope of this inventionbeing limited solely by the appended claims.

I claim:

1. A forming device comprising a first pair of rollers,

a second pair of rollers,

means rotatably mounting said first pair of rollers about an axis parallel to the axes of said rollers and bisecting an imaginary line interconnecting the axes of said rollers,

means rotatably mounting said second pair of rollers about an axis parallel to the axes of said second pair of rollers and bisecting an imaginary line interconnecting said axes of said second pair of rollers, means for simultaneously rotating said pairs of rollers about said axes of rotation for defining different passageways between adjacent rollers of said pairs,

and means for forcing a workpiece through said passageways.

2. A device as recited in claim 1 in which said means for rotating said pairs of rollers includes gear means interconnecting said mounting means for said pairs of rollers,

and said rollers being positioned with respect to each other so that in certain positions of rotation said imaginary line interconnecting said axes of said first pair of rollers is normal to said imaginary line interconnecting said axes of said second pair of rollers. 3. A device as recited in claim 1 in which said means for forcing a workpiece through said passageways includes means for forming spaced apertures in said workpiece,

and abutment means engageable with said workpiece therewith.

4. A device as recited in claim 1 including in addition a cylindrical member for receiving material formed in said roller means,

and means correlated with said means for forcing said workpiece through said passageway for rotating said cylindrical member and helically winding said formed material thereon.

5. A device as recited in claim 1 including in addition a sheet member receiving material formed by being forced through said passageway defined by said rollers, and resilient guide means on said sheet for limiting the lateral movement of said formed material on said sheet.

6. A forming device comprising a first pair of rollers having adjacent cylindrical surfaces,

a second pair of rollers having adjacent cylindrical surfaces,

the axes of said rollers being parallel, said rollers being arranged with an imaginary line interconnecting the axes of one of said pairs normal to a similar line of the other of said pairs,

whereby one roller of one pair presents its cylindrical surface intermediate said cylindrical surfaces of said other pair, thereby defining a curvilinear path around said surfaces, means for repositioning said rollers to locate one roller of the other pair of rollers intermediate said cylindrical surfaces of the remaining pair of rollers,

thereby defining a different curvilinear path around said surfaces, and means for pushing a strip of material through said paths. 7. A forming device comprising a first support member, a second member relatively reciprocative through a stroke toward and away from said first member, guide means on said first member for transmitting a workpiece therethrough,

said first and second members having cooperable punch and die means for forming an aperture in such a workpiece when said second member is adjacent said first member,

a drive member on said first member,

said drive member having a projection engageable with said workpiece at an aperture formed by said punch and die means, means for moving said drive member through a stroke for advancing said workpiece therewith, and roller means defining a curvilinear path for re ceiving said workpiece so advanced and forming said workpiece. 8. A device as recited in claim 7 in which said means for moving said drive member through its stroke is operable by said second member. 9. A device as recited in claim 7 in which said means for moving said drive means through said stroke includes a gear on said first member, a rack carrying said drive member, and linkage means interconnecting said gear and said second member,

whereby said reciprocation of said second mem ber reciprocates said gear for moving said rack and drive member through said stroke.

10. A device as recited in claim 7 in which said roller means includes a first pair of parallel rotatable rollers, a second pair of parallel rotable rollers, a shaft supporting said first pair of rollers,

said shaft being rotable about an axis intersecting the mid-point between said first pair of rollers, a second shaft supporting said second pair of rollers, said second shaft being rotatable about an axis intersecting the mid-point between said second pair of rollers, gear means interconnecting such shafts for providing equal and simultaneous rotation of said shafts, and means for rotating said shafts through a 90 degree are upon each stroke of said second member. 11. A forming device comprising a first set of at least two rollers, a second set of at least two rollers, means for moving said sets of rollers to a position in which one roller of said first set of rollers is relatively adjacent the midpoint between two rollers of said second set of rollers and spaced from the peripheries thereof,

thereby to define a path of predetermined contour through said rollers so positioned, and to a second position in which one roller of said second set of rollers is relatively adjacent the midpoint between two of said first set of rollers and spaced from the peripheries thereof,

thereby to define a path of a different predetermined contour through said rollers, and means for feeding strip material through said paths for thereby forming said strip material to substan-' tially said predetermined contours as defined by said rollers.

References Cited by the Examiner UNITED STATES PATENTS 8/10 Anduaga et a1. 7/53 Norman.

Claims

1. A FORMING DEVICE COMPRISING A FIRST PAIR OF ROLLERS, A SECOND PAIR OF ROLLERS, MEANS ROTATABLY MOUNTING SAID FIRST PAIR OF ROLLERS ABOUT AN AXIS PARALLEL TO THE AXES OF SAID ROLLERS AND BISECTING AN IMAGINARY LINE INTERCONNECTING THE AXES OF SAID ROLLERS, MEANS ROTATABLY MOUNTING SAID SECOND PAIR OF ROLLERS ABOUT AN AXIS PARALLEL TO THE AXES OF SAID SECOND PAIR OF ROLLERS AND BISECTING AN IMAGINARY LINE INTERCONNECTING SAID AXES OF SAID SECOND PAIR OF ROLLERS, MEANS FOR SIMULTANEOUSLY ROTATION SAID PAIRS OF ROLLERS, ABOUT SAID AXES OF ROTATION FOR DEFINING DIFFERENT PASSAGEWAYS BETWEEN ADJACENT ROLLERS OF SAID PAIRS, AND MEANS FOR FORCING A WORKPIECE THROUGH SAID PASSAGEWAYS.