US3388577A - Metal forming machine, traversing wipe shoe and control therefor - Google Patents

Description

June 18, 1968 s. M. DOLNEY 3,388,577

METAL FORMING MACHINE, TRAVERSING WIPE SHOE AND CONTROL THEREFOR Filed Aug. 13, 1965 5 Sheets-Sheet 1 WW 3 Q N INVENTOR- Zza ATTORNEY.

June 18, 1968 s. M. DOLNEY 3,388,577

METAL FORMING MACHINE, TRAVERSING WIPE SHOE AND CONTROL THEREFOR Filed Aug. 13, 1965 5 Sheets-Sheet 2 INVENT OR.

I 4 ATTORNEY June 18, 1968 S. M. DOLNEY METAL FORMING MACHINE, TRAVERSING WIPE SHOE AND CONTROL THEREFOR Filed Aug. 13, 1965 5 Sheets-Sheet 5 :33 34' 1 17 35\ F x f I /35 18\ I f l F J 7 J 7 59 i 59r 23E X 1/23 7 61 59 61 \22 1;; 1L 45 v 4'7-\ 48 49 L48 49 60? 5600* INVENTOR- ATTORNEY 3 June 18, 1968 s. M. DOLNEY METAL FORMING MACHINE, TRAVERSING WIPE SHOE AND CONTROL THEREFOR 5 Sheets-Sheet 4 '7 Filed Aug. 13, 1965 A405 ATTORNEY June 18, 1968 s. M. DOLNEY METAL FORMING MACHINE, TRAVERSING WIPE SHOE AND CONTROL THEREFOR 5 Sheets-Sheet 5 Filed Aug. 13, 1965 Zia ATTORNEY United States Patent FQRMING MACHHNE, TRAVERSING WEPE EsHQE AND CQNTROL THEREFQR Stanley M. Dolney, Parrna, Uhio, assignor to The Cyril Bath Company, Cleveland, Ohio, a corporation of Uhio Filed Aag. 13, 1965, Ser. No. 479,574 Claims. (Cl. 72-451) ABSTRACT 91* Lin DISCLOSURE The preferred embodiment of the invention is a wipe forming machine having a turntable rotatable about an upright axis and carrying a side face die; a traversing wipe shoe is driven by a reversible traversing piston and cylinder assemblage. A shoe carrier mounted on the support for movement toward and away from the table for applying the shoe to a workpiece laid against the face of the die. The shoe is carried on a rocker which is mounted on the carrier for rocking about an upright axis. A pair of thereby to control the traversing power means so as to n traverse the shoe carriage to maintain the reactionary thrust between the shoe and workpiece on the die directly through the rocking axis of the shoe at all times.

This invention relates to a metal forming machine and particularly to a combined stretch and wipe forming machine for forming an elongated length of metal about a side face die by wiping the stock with a wipe shoe into conformity with the side face of the die while the stock is maintained under endwise tension above its elastic limit by a suitable stretch forming assemblage.

For the purposes of llustration the invention is shown as embodied in a combined wipe and stretch forming machine of the general character described in my US. Letters Patent 2,810,421, issued Oct. 22, 1957, its embodiment in ordinary wipe forming machines and other machines being readily apparent from the illustrative example.

One of the principal objects of the present invention is to provide a wipe shoe by which the wipe forming forces appled to the shoe are applied in such a manner and by such means as to maintain the shoe substantially tangent to the side face of the die at the instantaneous point of tangency of the stock and die at all times during the wiping operation.

More specifically, an object of the invention is to provide a wipe forming assemblage wherein the wipe shoe itself rocks in seeking tangency with convex curvilinear surfaces of the side face die and, when slightly out of tangential relation, itself operates a control for a wipe shoe traversing mechanism so as to traverse the shoe along the side face of the die in the proper direction to cause the shoe to reassume promptly at position of tangency with the convex curvilinear side face of the die.

Various other objects and advantages will become apparent from the following description where reference is made to the drawings in which:

FIG. 1 is a top plan view of the combined wipe and stretch forming machine employing a traversing wipe shoe and embodying the principles of the present invention;

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FIG. 2 is a side elevation of the machine illustrated in FIG. 1;

FIG. 3 is an enlarged top plan view of the wipe shoe assemblage of the present invention;

FIG. 4 is a right side elevation of the wipe shoe assemblage shown in FIG. 3;

FIG. 5 is a hydraulic circuit employed in the present invention;

FIGS. 6A through 6C are diagrammatic representat-ions showing a sequence of operation of the machine;

FIG. 7 is a diagrammatic illustration showing the operation of the machine with a modified shape of side face die; and

FIG. 8 is a wiring diagram showing the automatic control of the present wipe shoe.

Referring to the drawings, the mahine comprises generally an elongated frame 1 on which a turntable 2 is mounted on a column 3 for rotation about an upright axis. The table carries a ring gear 4 driven by a suitable pinion gear 5, the pinion gear being driven in turn by a speed reducing gear transmission 6. The transmission 6 is driven by a hydraulic motor 7 to which pressure fluid is supplied by a hydraulic pump 8 driven by an electric motor 9.

Mounted on the frame 1 for movement toward and away from the table is a stretch forming assemblage 10. The assemblage comprises a carriage 11 supported by suitable rollers 12 and 13 on trackways 14 and 15 on the frame. Connected to the carriage for movement therewith is a hydraulic cylinder 16 in which 'a double ended piston 17 is operable. The piston has rods 18 and 19, respectively, which are connected to the frame 1 at opposite ends thereof, and the cylinder is connected to the carriage for movement therewith endwise of the frame. Pressure fluid for operating the piston and cylinder assemblage so as to yieldably urge the carriage 11 in a direction away from the table 2 with the force required for tensioning the stock above its elastic limits is provided by a hydraulic pump 20 driven by an electric motor 21. The pump is connected to the cylinder 16 through a conventional stop and reversing valve 22 which may be remotely controlled by a suitable solenoid 23, if desired. The valve 22 is connected to bores in the piston rods for admitting the pressure fluid into the cylinder 16 at opposite sides of the piston 17, selectively, and for venting the opposite sides, as required.

Mounted on the table 2 for rotation therewith is side face die D about which the stock S is to be stretch formed. A clamp 24 is fixedly secured on the table 2 and is adapted to grip one end of the length of stock S for movement of that end with the table as the stock is wrapped onto the die.

The stretch forming assemblage 10 includes an elongated arm 25 of which one end is connected to the sleeve 26 which is rockable on an upright column 27 on the carridge ll so that the arm can swing about an upright axis 28 parallel to the axis of the table 2. The free end of the arm carries a stretch forming head 30 adapted to grip the end of the length of the stock S opposite from the end gripped by the clamp jaw 24 for applying tensioning force to the stock.

The wipe shoe assemblage of the present invention comprises an elongated frame 31 upon which a traversing wipe shoe carriage 32 is arranged for guided movement lengthwise of the frame 31 in opposite directions alongside the table, and preferably parallel to the frame 1. The carriage 32 carries a traversing cylinder 33 on which is mounted a double end piston 34 having rods 35 at its opposite ends. The rods are connected to the frame 31. The cylinder 33 is of the reversible double acting type so that with proper introduction of pressure fluid it drives the carriage 32 in opposite directions, selectively, in a traversing path which extends lengthwise of the frame 31. Mounted on the carriage 32 for movement relative thereto in a path at right angles to the traversing path is a slide 36 which is guided in suitable slideways 37 on the carriage 32.

The structure thus far described is known in the art. However, instead of the conventional mounting of the wipe shoe on its slide 36 for movement toward and away from the side face of the die by a single reversible piston and cylinder assemblage connected to the slide, the wipe shoe, indicated at 40, is mounted on a rocker 41 which is rockable about an upright pivot 42 on the slide 36. The rocker has laterally extending arms 43 and 44 which are disposed at opposite sides of a vertical plane through the axis of a pivot 42 and parallel to the path of the slide 36, as indicated by the line XX in FIG. 3. The arms are connected to identical wipe forming piston and cylinder assemblages 45, respectively.

Each assemblage comprises a reversible cylinder 47 in which is mounted a piston 48 having a piston rod 49. Each cylinder is pivotally connected at its head end to the carriage 32 for swinging about an upright pivot 50.

The piston rods of the assemblages 45 are connected to the arms 43 and 44 by suitable pivots 51 and 52, respectively, which are spaced at opposite sides of, and equidistantly from, the plane XX. The cylinders 47 of the assemblages 45 are connected in parallel with each other. Since they are the same size, it is apparent that when shoe 40 is pressed against the side face of the die in a position such that the reactionary force of the die is in the plane XX, the assemblages are constrained to operate in unison, applying the same yieldable force to arms 43 and 44, respectively. Accordingly, they urge the rocker 41, in an unrocked position wherein it is at a right angle to the plane XX, toward the side face of the die. Whenever, due to a change in curvature of in position of the shoe along the side face of the die, the point of application of the reactionary force imposed by the die on the shoe 40 is offset from the plane XX, the part of the shoe at the opposite side of the plane XX from the point of application of the reactionary force offers less resistance to movement of the shoe toward the die face. Since the forces of the pistons 48 are at points equidistantly from the plane XX, the shoe will rock in a direction such that the part at the side of the plane X-X opposite from the point of application of the reactionary force moves toward the die as the pistons 48 seek to equalize the resistance and bring the reactionary force back to the plane XX. It will thus be seen that as long as the reactionary force against the wiping face of the shoe imposed by the die is on the plane XX, and this is through the axis of the pivot 42 and parallel to the path of the slide 36, the effect of the assemblages 45 will be to drive the shoe forwardly, but as the reactionary force migrates from one side to the other of the plane X-X, the shoe will automatically rock for the reasons heretofore disclosed.

The only way the shoe can overcome this imbalance is by traverse of the carriage 32 alongside the die. Accordingly, means are provided to effect the traverse in accordance with the angularity imposed on the shoe itself by the wipe forming forces and the reactionary force. For this purpose, the rocker carries an operating arm 54 which extends rearwardly from the axis of the pivot 42, and preferably is normal to the midportion of the wiping face of the shoe 40 so as to lie in the plane XX when the reactionary force is in such plane. Since the shoe 40 rocks due to the offset of the reactionary force relative to the midportion of the wiping face of the shoe, the arm 54 is swung in opposite directions. This arm is arranged to operate electric limit switches, later to be described, these switches being arranged to cause the traversing power means to traverse the carriage 32 in the proper direction to dispose the point of application of the reactionary force in the plane XX.

For operating the machine, a suitable hydraulic system is provided, as best illustrated in FIG. 5. Pressure fluid is supplied by the pump 20 to the reversible and stop valve 22, which connects the pump to the stretch forming assemblage 10, as mentioned hereinbefore, at either end selectively, and concurrently vents the opposite end to a sump. In the form illustrated, the connections to the opposite ends of the cylinder are through suitable bores in the rods 17 and 18 of the piston 16.

Likewise, pressure fluid from the pump 20 is delivered, through a suitable stop and reversing valve 59, to opposite ends of the traversing cylinder 33 for traversing the wipe shoe 4d. The valve 59 may be controlled by suitable solenoids 59 and 591'. The valve 59 is preferably self-restoring and is moved by its solenoids when they are energized, solenoid 59 when energized, setting the valve 59 for causing a forward traverse of the wipe shoe opposite to the direction of table rotation, and the solenoid 59r, when energized, causing a reverse traverse for the wipe shoe.

Pressure from the pump 20 is also delivered through suitable reversing and stop valves 60! to the assemblage 45, respectively. Each valve 60 is provided with solenoids 60] and 601', respectively, for controlling the valves 60 forward and reverse movement of the shoe at a right angle to its traverse path. Overload relief valves 61 may be used where desired in the circuit. The valves 22, 59, and 60 can control the operation of the stretch assemblage, the traversing of the Wipe shoe, the application of the wipe shoe to the stock and its retraction therefrom.

Referring next to FIGS. 6a through 6c, diagrammatic illustrations showing typical type of operation of the machine is shown. In FIGS. 6a through 60 it is assumed that the turntable 2 is turning counterclockwise, as indicated by the arrow 63. The Wipe shoe 40 is to be applied to the stock S which is being tensioned by the stretch forming assemblage 10 which exerts a tensioning force in the direction indicated by the arrow 64. It is desired to form the length of stock about the face of the die D, starting at position P passing successively through. positions P2, P3, P4,, P5 and P6- First the shoe 40 is applied to the stock adjacent the end gripped by the jaw 24. Assuming that the die has a flat face from the position P to position P then the reactionary forces on the shoe are distributed uniformly along the length of the shoe in a direction traverse of the shoe. Hence, the wiping face of the shoe 40 remains normal to the plane XX, heretofore described. In this position, with the table stationary, the shoe 40 is traversed forwardly, which is in a direction indicated by the arrow 64- and is opposite to the normal direction of rotation of the table indicated by the arrow 63. When the shoe reaches the position P and passes very slightly therebeyond, the table is started. This, of course, may be done manually or by a suitable limit switch. Since the leading end of the shoe, which is the left end in FIGS. 6a through 6c, is no longer subject to reactionary forces imposed by the side face of the die D, While at the same time, the portion of the shoe to the right of the plane XX remains so subject to the reactionary forces, the shoe rocks so that its left end moves inwardly toward the axis of the table. This rocking is permitted because of the manner in which the assemblages 45 are arranged. When this rocking has proceeded a very few degrees, the arm 54 operates a reverse limit switch 70 which causes the shoe to traverse to the right or rearwardly about the die while the table is rotating so that the point of contact of the die with the curved surface between the positions P and P approaches the plane XX. This reverse traverse continues until the point of contact reaches the plane X-X, whereupon the arm 54 operates a switch 71 which stops the traverse. If the shoe overruns during the rearward traverse, the arm operates a limit switch 72 which causes forward traverse which continues until the switch 71 isagain operated to stop the forward traverse. During this traversing, the table is rotating, as indicated by the arrow 63.

When the shoe 40 has centered at the position P the table is stopped by suitable limit switches and the shOe then traverses to the point of position P whereupon the table starts and the shoe traverses from position P to position P Again the table stops and the shoe traverses from position P to complete the article. If desired, the shoe 40 may be retracted while the stretch assemblage initially lays the stock against the flat portions of the face, such as positions from P to P and P to P the shoe returning and beginning its traverse in each instance at the location at which it was attracted. This is to assure effective tensioning of the stock for the full length of the straight portions.

In some instances, however, the curvatures of the die are not of the same radius throughout. For example, as illustrated in FIG. 7, a die D is shown as having a corner portion of which the radius from positions P to P is smaller than that from positions P to P With this shape of die, when the left end of the shoe passes position 3P the table starts. The left end of the shoe moves outof contact with the die and the shoe rocks about its axis in a clockwise direction, causing the arm 54 to operate the limit switch 79 for rearward traverse. When the shoe suddenly is confronted with the change in radius which causes the left end of the shoe to be resisted in movement radially of the table to a lesser extent than the right end, the shoe rocks in a counterclockwise direction. Thereupon the arm 54 is swung in the opposite direction and operates the limit switch 73 which causes traverse of the shoe in the forward direction or the direction of rotation of the table, thus seeking to move so that the reactionary force is brought to the plane X-X. The shoe thus continuously seeks a position wherein the reactionary force of the die is in the plane X-X. As hereinbefore mentioned, the shoe has reached the position P the table is stopped and another limit switch causes the shoe to traverse forwardly in the manner heretofore described along the flat intermediate portion of the die face while the table remains stationary.

For obtaining these various operations, the table and slide may be provided with conventional limit switches and adjustable trigger devices. As illustrated in FIG. 8, the limit switches 70 and 72 may be connected to the solenoids 59r and 59 of the valve 59.

A forward traverse switch 73 for the wipe shoe is closed manually and energizes a relay 74 which close-s two normally open contacts 74,, and 74 No traverse occurs because limit switches 70 and 72 are open. Limit switch 71 is closed. If the shoe 40 rocks and closes limit switch 70, relay 75 is energized and closes contacts 75 and 75 thus providing a holding circuit for relay 75 through limit switch 71 and energizing solenoid 591*, causing the shoe to traverse rearwardly. If the shoe then overruns and hence rocks in the opposite direction, it opens limit switch 76 and then opens limit switch 71, thereby dropping out relay 75. As the arm 54 passes further in this opposite direction, it allows limit switch 71 to close and then closes limit switch 72.

Closure of limit switch 72 energizes a relay 76 through contacts 74 thus closing contacts 76 and 76, to provide a holding circuit for relay 76 and energizing solenoid 59f, thereby causing the shoe to traverse in the forward direction.

It must be remembered that during this seeking of tangency, the table continues to rotate, so that the part of the die face trailing the wipe shoe tends to drop away radially of the table while the part leading tends to move outwardly radially of the table relative to the shoe. As the trailing part drops away, the shoe advances to bring the reactionary force to the plane XX.

It is apparent, from the foregoing description that the position to which the shoe is rocked by the wipe forming assemblages themselves controls the traverse, :and the usual die followers and the like are unnecessary. The response is almost immediate, as the'shoe need rock more than a few degrees in either direction from normal, to

traverse properly for correction to normal. A maximum of 15 rock in either direction may be permitted but generally is not required.

In the description and claims, certain parts of the machine are referred to as upright and as horizontal. These words are used for brevity in description of the relative positions of such parts, and not in their absolute senses.

Having thus described my invention, I claim:

1. In a wipe forming machine, a frame, a turntable mounted thereon for rotation about an upright axis, a side face die on the table;

a traversing wipe shoe support mounted on the frame for movement in a horizontal plane in opposite directions alongside the table in a predetermined traversing path;

reversible traversing power means connected to the frame and support for moving the support in said opposite directions along said path;

a shoe carrier mounted on the support for movement relative thereto in a horizontal plane in opposite directions along a pressure applying path extending transversely of the traversing path;

a rocker pivotally mounted on the carrier for rocking relative thereto about an upright pivotal axis;

a pair of power applying wipe piston and cylinder assemblages each connected at one end to' the support, said assemblages being connected at their opposite ends to the rocker at opposite sides of an upright plane parallel to the carriage path and extending through said pivotal axis;

a hydraulic circuit connecting the assemblages in parallel with each other for operation concurrently in the same direction for yieldably urging the carrier toward the side face of the die with opposite and balanced turning movements about said axis;

whereby when the shoe is in contact with the die and the resultant reactionary force imposed by the die on the shoe is in said plane, the shoe retains a normal unrocked position relative to its carriage, and when the resultant reactionary force is offset from said plane, the shoe is caused to rock relative to its carriage about said pivotal axis; and

control means driven by the rocker in relation to its rocked position for controlling the traversing power means.

2. A structure according to claim 1 wherein the traversin power means comprise a reversible traversing piston and cylinder assemblage;

the control means include solenoid operated stop and reversing valve means for controlling the supply of pressure fluid tothe said reversible traversing assemblage, and switch means for energizing solenoid means so as to operate the valve means to cause traversing in opposite directions, respectively, and for deenergizing the solenoid means so as to operate the valve means to stop traversing.

3. A structure according to claim 2 wherein the rocker rocks about the pivotal axis from said normal unrocked position to predetermined actuating positions at opposite sides of the normal position;

the switch means include a stop switch operable to deenergize the solenoid means to stop traversing, a forward traverse switch operable to energize the solenoid means to set the valve means for forward traverse, a reverse traverse switch operable to energize the solenoid means to set the valve means for rearward traverse, and means are provided which move in fixed position relative to the rocker tooperate the forward and reverse switches when the rocker is at said actuating positions, respectively, and to operate the stop switch when the rocker is at said normal unrocked position.

4. A structure according to claim 1 wherein the control means are driven in opposite directions in fixed relation to the rocked position of the rocker in opposite directions, respectively, from said normal unrocked position, and are operative to cause the traversing power means to traverse the traversing wipe shoe support in the one of its said opposite directions for restoring the resultant reactionary force on shoe to said plane.

5. A structure according to claim 1 wherein the wipe piston and cylinder assemblages aIe identical and are connected to the rocker equidistantly from, and at opposite sides of, said plane.

References Cited UNITED STATES PATENTS 2,949,146 8/1960 Whiteman 72-151 5 RICHARD J. HERBST, Primary Examiner.

R. D. GREFE, Examiner.

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