US3175385A - Drawbench - Google Patents

Description

March 1965 cs. A. MITCHELL ETAL 3, 75

DRAWBENCH 3 Sheets-Sheet 1 Filed May 1. 1963 N li R m m V W. E an N\ 3 U Q\ W\ mu 3 mm q; L 1 Q u an GEORGE A. MITCHELL DANIEL L. LOMBARD 7M 7 JTTORNE) March 1965 a. A. MITCHELL ETAL 3,

DRAWBENCH Filed May 1, 1963 3 Sheets-Sheet 2 INVENTOR. GEORGE A. MITCHELL DANIEL L. LOMBARD ATTORNEY March 1965 s. A. MITCHELL ETAL ,175,

DRAWBENCH Filed May 1, 1963 s sheets-sheet a INVENTOR. GEORGE A. MITCHELL DANIEL L. LOMBARD United States Patent 3,175,385 DRAWBENCH George A. Mitchell and Daniel L. Lombard, Youngstown, Ohio, assignors to George A. Mitchell Company, Youngstown, Ohio, a corporation of Ohio Filed May 1, 1963, Ser. No. 277,369 Claims. (Cl. 72-281) This invention relates to drawbenches adapted to draw workpieces through a die. More particularly, the invention relates to drawbench apparatus for preventing damage to the forward ends of thin-walled tubes and the like which, due to sudden release of tension, jump forwardly and strike the draw carriage of the bench at the completion of a draw.

As is well known to those skilled in the art, a drawbench employs, as a basic component, a circular die through which a workpiece is drawn in order to elongate it and reduce its diameter. In the drawing operation, an end of a workpiece to be drawn is passed through the die and engaged by gripper jaws carried on a draw carriage or dolly which travels on a track extending parallel to the central axis of the die. The draw carriage is forced along its track outwardly and away from the'die, thereby pulling the workpiece through the die.

In order to increase the production output of a drawbench, a plurality of workpieces are simultaneously drawn through a corresponding number of spaced dies during one drawing operation. It is a common occurrence in the drawing of these workpieces for the same to jump forwardly with considerable force as the trailing ends thereof pass through the dies, the obvious reason being that the workpieces are under substantial tension during the drawing operation and the sudden release of such tension is accompanied by a release of energy which propels them forwardly. This is a serious problem in that the forward ends of the workpieces are driven against the draw carriage; and in the case of thin-walled tubing drawn on the bench, the forward ends of the tubes are often buckled and rendered unsuitable for a subsequent drawing operation, or at least partially so.

In the past, various arrangements have been proposed for absorbing the kinetic energy of the workpieces as they leave the dies in an effort to prevent damage to their forward ends. Most previous arrangements of this type employed shock absorbers on the draw carriage or deflectors which are designed to direct the workpieces down into a raceway where they can expend their kinetic energy. Other arrangements have employed double-die plates, tube-end grabbers and the like. Although such arrangements are somewhat satisfactory for large diameter or thick-walled tubing drawn on the bench, they are not effective for thinwalled, small diameter tubing. In any event, regardless of the type of workpieces drawn on the bench, shock absorbers, double-die plates, tube-end grabbers and the like do not facilitate even and uniform stacking of the drawn workpieces in a receiving bin beneath the bench. In present tube benches, for example, it often happens that one or more tubes in a draw will come to rest in the receiving bin as much as eight or ten feet ahead of the others. When these tubes are redrawn in a succeeding operation, the ends of the tubes which vary in location from those in the major portion of the bundle may be out of the reach of the operator trying to 3,175,385 Patented Mar. 30, 1965 load them through a pinch roll in a subsequent drawing operation. This uneven stacking of drawn tubes has been a persistent problem in the dr-awbench industry, one to which no satisfactory solution has ever been advanced.

Accordingly, as an overall object, the present invention seeks to provide a new and improved means in a drawbench for absorbing the kinetic energy of newly-drawn tubes in a manner to prevent damage to their forward end as a result of being propelled against the draw carriage at the conclusion of a drawing operation.

Another object of the invention is to provide apparatus in a drawbench construction for facilitating even and uniform stacking of drawn tubes in a receiving bin beneath the bench.

In accordance with the invention, the means for preventing damage to the workpieces by virtue of their being propelled forwardly at the completion of a draw comprises apparatus, preferably in the form of a pair of pinch rolls, which are separated when the draw carriage is adjacent the die preparatory to a drawing operation, but which are forced together into frictional engagement with the workpieces during the drawing operation when the draw carriage moves away from the die. One of the pinch rolls is preferably driven through an over-running clutch mechanism at a peripheral speed not exceeding the speed of the draw carriage. If a single workpiece is being drawn on the bench, it will tend to jump forwardly at the com pletion of a draw due to the sudden release of tension mentioned above; however because of the inertia of the roll and its associated drive mechanism, the pinch rolls will resist any movement of the workpiece at a speed above their normal peripheral speed. Furthermore, although the workpiece may slide between the pinch rolls before decelerating to the peripheral speed of the rolls, it will not leave. the rolls until its kinetic energy has been dissipated. After the workpiece has been slowed down to the peripheral speed of the rolls, it will continue to move through the rolls by virtue of the fact that one of rolls is driven until its trailing end passes through the interstice between the rolls, the tubes thereafter dropping down into a neat bundle with previously-drawn workpieces all having their ends in substantial alignment.

In the case of a multiple draw, the operation is similar, except that due to the varying lengths of the workpieces, they may not leave the dies at the same time. As the first tube, for example, leaves its associated die, it will attempt to jump forwardly; but its kinetic energy will be dissipated by sliding between the aforesaid pinch rolls. These rolls are retarded due to the fact that they are still in engagement with tubes which have not as yet left the dies. This process is repeated as each tube leaves its associated die until the last tube is drawn, in which case the operation is the same as that for a single workpiece with the inertia and friction of the system serving to dissipate the kinetic energy of the tube.

The above and other objects and features of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings which form a part of this specification, and in which:

FIGURE 1 is a schematic side view of one embodiment of the invention;

FIG. 2 is a top view of the arrangement shown in FIG. .1;

FIG. 3 is a cross-sectional view of a drawbench showing the energy-dissipating means of the invention and its relationship to the tube-storage rack of the drawbench;

FIG. 4 is a cross-sectional view taken along line 1VIV of FIG. 3 showing details of the lower roller assembly of the energy-dissipating means;

FIG. 5 is a cross-sectional view of the draw carriage shown in FIGS. 1-3 and taken substantially along line V-V of FIG. 2; and

FIG. 6 is a cross-sectional view taken substantially along line VIVI of FIG. 5 and showing the details of the grip bits of the draw carriage.

Referring now to the drawings, and particularly to FIGS. 1 and 2, three tubes 10, 12 and 14 are shown being drawn simultaneously through three dies 16, 18 and 20, respectively, arranged in side-by-side relationship in a die plate 22. The forward ends of the tubes 1044 are engaged by a gripper jaw assembly 24, hereinafter de scribed in detail, carried on a draw carriage 26. The draw carriage 26 may be forced away from the die plate 22 by means of a chain drive such as that shown in US. Patent No. 2,861,679; however it is preferably driven by means of a hydraulic cylinder arrangement.

The draw carriage 26 is provided with bottom rollers 23 and side rollers 25 adapted to engage the horizontal and vertical portions of a pair of L-shaped tracks 28 and 36 (FIGS. 1, 2 and 3). The tracks 28 and 31 are carried on a plurality of spaced frame sections, one of which is shown in FIG. 3. Each section includes an upright member 27 and a horizontally disposed cantilever beam 29 extending outwardly from the upright member or post 27. Depending downwardly from the outer end of the cantilever beam 29 is a short beam section 31 which carries the track 30, the other track 28 being carried on upright member 27. As will be understood, frame sections such as that shown in FIG. 3 are spaced along the entire length of the tracks 28 and 30 and support the draw carriage 26 along its path of travel. Above the cantilever beam 29 is a tube storage rack 33 for the storage of tubes or other workpieces about to be drawn on the bench. Beneath the tracks 28 and 30 is an inclined runout table 35 adapted to receive the drawn tubes and direct them into a storage bin 37 positioned at the side of the main drawbench frame. Further details of the drawbench proper may be had by reference to the aforesaid US. Patent No. 2,861,697.

The details of the gripper jaw assembly 24 are shown in FIGS. 2, 5 and 6. As shown in FIG. 2, the draw carriage 26 is provided with rigid side members 32 and 34 having keyways 36 and 38, respectively, machined in their forward ends. The keyways 36 and 38 receive cooperating keys in a gripper head 40 which carries the gripping jaws for engaging the forward ends of the tubes -14. The gripper head 40 (FIGS. 5 and 6) comprises a heavy block of steel having formed therein a plurality of forwardly converging guide slots 42 adapted for the reception of stock-engaging grip bits 44 and 46, the arrangement being such that upon forward movement of the hits the same are caused to converge while upon rearward movement they are caused to diverge. The guide slots 4-2 are open at the lower side of the gripper head 40, there being a plurality of spaced plates 48 provided to partially enclose the openings thus formed and retain the grip bits 44 and 46 therein.

Each of the bits 44 and 46 is provided with a transverse slot 50 for the reception of the lower end of a lever bar 52 pivotally connected to the draw carriage 26 as at 54. Midway between the ends of the lever bar 52 is a pin 56 adapted to engage the forward end of a plunger 6tl' which is actuated by an air cylinder 62. The other side of the pin 56 is adapted to be engaged by a spring-loaded plunger 64 slideable in a bore provided in the gripper head 40. With the arrangement shown, movement of the plunger 60 from left to right as viewed in FIG. 5 will 1 cause the grip bits 44 and 46 to converge and grip the reduced diameter end of a tube passed through one of the dies 16-25), the spring-loaded plunger 64 serving to insure that the grip bits are open when the draw carriage approaches the die plate 22 preparatory to a drawing operation.

In operation, when the draw carriage 26 approaches the die plate 22, air under pressure will be introduced into the cylinders 62 by suitable means, not shown, thereby causing the grip bits 44 and 46 to converge upon and grip the reduced diameter ends of tubes extending through the dies 16-20. After the grip bits engage the ends of the tube blanks, the draw carriage 26 is forced away from the die plate 22, thereby initiating the drawing operation. At this time, the air pressure on cylinders 62 is released. However, it will be observed that the application of a drawing force by the grip bits 44 and 46 merely tends to draw the same more tightly into engagement with the tube blanks so that air pressure is no longer necessary for this purpose.

As the drawing operation is completed, the tube blanks 10-14 will snap free of the dies 16-21). When the tubes jump forwardly due to the release of kinetic energy, they will cause the grip bits 44 and 46 to diverge, thereby automatically releasing the forward ends of the tubes which then tend to jump forwardly underneath the draw carriage 26. If no means is provided for preventing the tubes from jolting forwardly, they may slam against the end of the bench and become damaged. As was mentioned above, shock absorbers, deflectors and the like have been previously employed on the draw carriage 26 for the purpose of dissipating the kinetic energy of the newly-drawn tubes; however these devices do not prevent damage to the ends of the tubes, particularly thin-walled tubes.

Therefore, in accordance with the present invention, a pair of rollers 68 and '70, carried on pivoted arms 69 and 71, (FIGS. 1, 2 and 3) are employed to frictionally engage the tubes 18, 12 and 14 during a drawing operation. As shown in FIGS. 2 and 3, each roller comprises a plurality of rubber or the like rings 72 separated by steel spacers 74, the rings 72 being aligned with the dies 16-26 such that they will engage the opposite sides of the tubes 10-14.

As will be understood, the rollers 68 and '76 will be in the path of the draw carriage 26 when it approaches the die plate 22. Consequently, some means must be provided for moving the rollers 68 and '70 and their supporting arms 69 and 71 into the dotted-line position shown in FIG. 1 when the draw carriage 26 is adjacent the die plate 22. For this purpose, the upper arm 69 is pivotally supported on shaft 76 carried on the cantilever beam 29 (FIG. 3). Shaft 76, in turn, is connected to an air cylinder '78 through linkage 81). The supporting arms '71 for roller 76, on the other hand, are carried on a shaft 82 beneath the run-out table 35 (FIG. 3) and are freely rotatable thereon. Downward movement of the roller 76, however, is limited by a rubber-covered drive roller 84 (FIGS. 3 and 4) carried on an arm 86 which is also pivotally supported on the shaft 82 and rotatable independently of the arms 71. The forward end of arm 36 is connected to the piston of an air cylinder 90, substantially as shown in FIG. 4. Thus, when the lower end of the cylinder 96 is pressurized, the drive roller 84- will move upwardly, thereby forcing roller 70 upwardly also such that its rubber rings 72 are in engagement with the undersides of tubes 1014. When the top of cylinder 91]! is pressurized, however, drive roller 84 will be forced downwardly with roller '70 and arms 71 following under the force of gravity. Limit switch means, not shown herein, may be employed in the usual manner to pressurize the cylinders 78 and 96 to move the rollers 68 and 7t) upwardly and downwardly, respectively, when the draw carriage approaches the die plate 22, this limit switch means also serving to pressurize the cylinders 78 and 91) in the opposite sense when the draw carriage moves away from the die plate 22 to the point where it is no longer in the path of the rollers 68 and 7 ti.

With reference, now, to FIGS. 3 and 4, a bar 8% is connected between the lower arms ll. Carried on the bar 83, as best shown in FIG. 3, is a Micarta (trademark) plate 91 which extends above the periphery of the lower roller 70 and is provided with three notches 92. The notches 92 are aligned with the rubber rings '72 on the lower roller 7d and serve to guide tubes ill-l4 after they have left the dies 16-26. That is, the slots 92 in the plate Q1 will prevent sideways movement of the tubes and insure that they are maintained in position between the rubber rings 72 on the upper and lower rollers 68 and '76.

In the operation of the device, the cylinders 73 and 90 will be pressurized to separate the rollers 68 and 70 as the draw carriage 26 approaches the die plate 22. Thereafter, the cylinders 62. on the draw carriage 26 will be pressurized to cause the grip bits 44 and 46 to converge and grip the reduced diameter ends of the tubes 1944 extending through the dies 1646. The draw carriage 26 will then be caused to move away from the die plate 22 by chains or a hydraulic cylinder arrangement to initiate the drawing operation. After the draw carriage 26 has moved past the roller 68 and 79, the cylinders 78 and so will be pressurized to move the rings 72 on rollers 68 and 70 into frictional engagement with the tops and bottoms, respectively, of the tubes Ill-14.

At the completion of a drawing operation when the trailing ends of the tubes H344 pass through the dies, they will jump forwardly due to the sudden release of kinetic energy. It can be seen that with the arrangement of rollers 63 and 76, the varying kinetic energy of the tubes is dissipated by the individual tubes skidding different distances through the retarding rollers 68 and 7%. Thus, if three tubes are being drawn, possibly one will skid fifteen inches, the next twenty-four inches, the last possibly ten inches. However, all of these distances are less than the distance from the die plate 22 to the roller 68 and 70 which, for example, may be on the order of about four feet. In this manner, the speed of each tube as it leaves the pinch rolls will always be the draw speed as it is dispatched from the interstice between a pair of rings 72 on the rolls, giving it a more or less uniform trajectory as it falls downwardly onto the inclined run-out table 35' provided in the drawbench frame beneath the tracks 28 and 35) (FIG. 3). As each tube is discharged from between the rollers 68 and 70, it will roll downwardly on the in clined table 35 into engagement with a pivoted stop member 94, this stop member being actuated by means of an air cylinder 96. In the usual case, the stop member 94 will be in the position shown by full lines in FIG. 3 until each of the three tubes 15-14 has been drawn and comes to rest against the stop member. Thereafter, the cylinder 96 will be pressurized to rotate the stop member 94 in a counterclockwise direction and into the dotted line position shown where the tubes are discharged into the receiving bin 37.

It will be appreciated that when one or more tubes leave the dies and slide through the rollers 68 and 7! while another tube or tubes are still being drawn and in tension, the tubes still being drawn will retard rotation of the rollers 68 and '70 to a peripheral speed not exceeding that of the draw carriage 26. Thus, the tubes still in tension will serve, in effect, as a retarding means for those which have left the dies. Furthermore, after the drawn tubes have stopped skidding through the rollers, the continued movement of the tubes still under tension will rotate the rollers 68 and 70 to advance those tubes which have left the dies until they pass through the interstice between the rollers and drop onto the run-out table 35.

It will be appreciated that the condition just described does not exist for the last tube or tubes to leave the dies. That is to say, when the last tube or tubes leave the dies, there are no other tubes still in tension to retard rotation of the rollers 68 and 7t and to advance the tubes out of the interstice between the rollers after they have stopped skidding. Accordingly, a drive motor 95 (FIG. 3) is provided which is connected to, and rotates, the shaft 82. Shaft 32, in turn, is connected through chain drive 98 and an overrunning clutch dill) to the drive roller 84, the overrunning clutch ltltl permitting relatively free rotation of the rollers 7d and 84- in the forward direction at a speed greater than the speed established by the drive motor 95. When the cylinder is pressurized to move roller 70 upwardly into engagement with the undersides of tubes being drawn, the motor 595 will tend to rotate the roller 70 in a counterclockwise direction as viewed in FIGS. 1 and 4. However, the speed of motor is such as to rotate the roller '70 at a peripheral speed which is preferably below the speed of the draw carriage 26 during a drawing operation. Consequently, until the last tube leaves its die, the roller '70 will overrun the motor 95, the motor being unable to retard the rollers 68 and 7% by virtue of the overrunning clutch ill-ll.

As the last tube or tubes leave the dies, they will tend to jump forwardly and accelerate the rollers 68 and 7t). Acceleration of the tubes, however, will be retarded by the inherent inertia of the rollers so that the tube or tubes will still be decelerated by skidding between the rollers 68 and 'Ytl or by dissipation of energy through rotation of the rollers 6%, 70 and 84. In certain cases, depending upon the Weights of the rollers 68, '70 and 84, their inherent inertia may be insuiiicient to stop the tubes. in this latter case, a friction brake, schematically illustrated at 102, may be provided on the roller 34, for example, for the purpose of dissipating the kinetic energy of the tubes. After the last tube or tubes have been decelerated, the motor as will then drive the roller 84 through the slip clutch ltltl to advance the drawn workpieces out of the interstice between the rollers as in the case of the previously-drawn tubes. As the tubes leave the rollers, they all have substantially the same forward speed and, therefore, drop down onto the inclined table 35 and into bin 37 in a neat bundle with their ends in alignment preparatory to a succeeding drawing operation.

Although the invention has been shown in connection with a certain specific embodiment, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention.

In the claims which follow, the term means for retarding rapid acceleration of at least one of the rollers '68 or 79 is defined as any device such as roller 34 or clutch 1% which will impede rotation of the rollers at a speed above their normal speed during the drawing operation, and also includes the inherent inertia of the rollers themselves as well as a tube which has not as yet left its die.

We claim as our invention:

1. In a drawbench of the type including a drawing die, a track structure extending parallel to the axis of said die on one side thereof, and a draw carriage movable along said track structure for pulling workpieces through the die; the improvement of means for preventing damage to the workpiece by virtue of its being propelled forwardly as its trailing end leaves the die, the said means comprising a pair of members positioned adjacent said die above and below the die axis and arranged to frictionaily engage opposite sides of the workpiece during a drawing operation when the draw carriage moves away from said die, and means for moving said members away from the central axis of said die when the draw carriage approaches the die to permit the draw carriage to engage a workpiece preparatory to a drawing operation.

2. In a drawbench of the type including a drawing die, a track structure extending parallel to the axis of said die on one side thereof, and a draw carriage movable along said track structure for pulling workpieces through sac sees the die; the improvement of means for preventing dam age to the workpiece by virtue of its being propelled forwardly as its trailing end leaves the die, the said means comprising a single first roller device having an axis extending transverse to the axis of said die and. arranged to abut one side of the workpiece during a drawing op eration, and a single second roller device arranged to abut the other side of the workpiece opposite the first roller device during a drawing operation, at least one of said roller devices being such as to impede rapid acceleration of the workpiece whereby the kinetic energy of a workpiece leaving the die will be dissipated.

3. In a drawbench of the type including a drawing die, a track structure extending parallel to the axis of said die on one side thereof, and a draw carriage movable along said track structure for pulling workpieces through the die; the improvement of means for preventing damage to the workpiece by virtue of its being propelled forwardly as its trailing end leaves the die, the said means comprising a first roller having an axis extending trans verse to the axis of said die and arranged to abut one side of the workpiece during a drawing operation, a second roller arranged to abut the other side of the workpiece during a drawing operation, said rollers being positioned closely adjacent said die at said one side thereof, means for retarding rapid acceleration of at least one of said rollers whereby the kinetic energy of a workpiece leaving the die will be dissipated by the retarded roller, means for moving said rollers away from the central axis of said die when the draw carriage approaches the die, and means for moving said rollers toward the longitudinal axis of said die and into engagement with the workpiece after the draw carriage has moved away from the die during the initial period of a drawing operation.

4. In a drawbench of the type including a drawing die, a track structure extending parallel to the axis of said die on one side thereof, and a draw carriage movable along said track structure for pulling workpieces through the die; the improvement of means for preventing damage to the workpiece by virtue of its being propelled forwardly as its trailing end leaves the die, the said means comprising a first roller having an axis extending transverse to the axis of said die and arranged to frictionally engage one side of said workpiece during a drawing operation, a second roller having an axis extending transverse to the axis of said die and arranged to frictionally engage the other side of said workpiece during a drawing operation, apparatus for moving said rollers away from the axis of said die when the draw carriage is adjacent the die, and means for thereafter moving the rollers toward the axis of the die and into engagement with a workpiece drawn through the die when the draw carriage moves away from the die.

5. In a drawbench of the type including a drawing die, a track structure extending parallel to the axis of said die on one side thereof, and a draw carriage movable along said track structure for pulling workpieces through the die; the improvement of means for preventing damage to the workpiece by virtue of its being propelled forwardly as its trailing end leaves the die, the said means comprising a first roller having an axis extending transverse to the axis of said die and arranged to abut one side of the workpiece during a drawing operation, a second roller arranged to abut the other side of the workpiece during a drawing operation, and means for rotating at least one of said rollers in a direction to move the workpiece away from the die, said latter-mentioned means comprising a drive motor, and overrunning clutch means connecting said drive motor to said one roller, the arrangement being such that at the completion of a draw when the trailing end of the workpiece passes through the die the rollers will retard any tendency of the workpiece to accelerate the rollers, the drive motor serving to advance the workpiece out of the interstice between the rollers after it has initially left the die.

6. In a drawbench of the type including a plurality of dies arranged in side-by-side relationship and having parallel axes, a track structure extending parallel to the axes of said dies on one side thereof, and a draw carriage movable along said track structure for pulling work pieces through the dies; the improvement of means for preventing damage to the forward ends of workpieces by virtue of their being propelled forwardly as their trailing ends leave the dies, the said means comprising a first roller having an axis extending transverse to the axes of said dies and arranged to abut the tops of the workpieces during a drawing operation, a second roller having an axis extending transverse to the axes of said dies and arranged to abut the bottoms of the workpieces during a drawing operation, motor means for driving one or" said rollers such that it has a peripheral speed not exceeding the speed of said draw carriage, and overrunning clutch means interconnecting said motor means with said one roller to retard acceleration of the rollers above a peripheral speed exceeding that of the draw carriage.

7. The improvement of claim 6 wherein the surfaces of said rollers are formed from material providing a high coefficient or resistance between the rollers and the workpieces to thereby prevent substantial slidin movement between the rollers and the workpieces.

8. In a drawbench or" the type including a plurality of drawing dies arranged in side-byside relationship and havin their axes extending parallel to each other, a track structure extending parallel to the axes of said dies on one side thereof, and a draw carriage movable along said track structure for pulling workpieces through the dies; the improvement of means for preventing damage to the workpieces by virtue of their being propelled forwardly as their trailing ends leave the dies, the said means comprising a first roller having an axis extending transverse to the axes of said dies and arranged to abut the tops of said workpieces during a drawing operation, a second roller having an axis extending transverse to the axes of said dies and arranged to abut the bottoms of the workpieces during a drawing operation, means for retarding rapid acceleration of at least one of said rollers above a peripheral speed exceeding the speed of said draw carriage whereby the kinetic energy of a workpiece leaving the die will be dissipated by the retarded roller, means for moving said first and second rollers upwardly and downwardly respectively away from the axes of said dies when the draw carriage approaches the dies preparatory to a drawing operation, and means for movin said rollers toward each other and into engagement with the tops and bottoms of the workpieces after the draw carriage has moved away from the dies.

9. In a drawbench of the type including a drawing die, a track structure extending parallel to the axis of said die on one side thereof, and a draw carriage movable along said track structure for pulling workpieces through the die; the improvement of means for preventing damage to the workpiece by virtue of its being propelled forwardly as its trailing end leaves the die, said means comprising a first friction device arranged to abut one side of the workpiece during a drawing operation, a second friction device arranged to abut the other side of the workpiece during a drawing operation, at least one of said friction devices comprising a roller having an axis extending transverse to the axis of said die, means for retarding acceleration of said roller whereby the kinetic energy of a workpiece leaving the die will be dissipated by the retarded roller, and means for simultaneously moving said friction devices toward or away from opposite sides of a workpiece.

10. In a drawhench of the type including a drawing die, a track structure extending parallel to the axis of said die on one side thereof, and a draw carriage movable along said track structure for pulling workpieces through the die; the improvement of means for preventing damage to the workpiece by virtue of its being propelled forwardly as its trailing end leaves the die, the said means comprising a single pair of friction members positioned above and below the die axis and arranged to substantially simultaneously frictionally engage opposite sides of the workpiece during a drawing operation when the draw carriage moves away from said die and before the trailing end of the workpiece passes through the die, and means for substantially simultaneously moving said members away from the central axis of said die when the 10 draw carriage approaches the die to permit the draw carriage to engage a workpiece preparatory to a succeeding drawing operation.

References Cited by the Examiner UNITED STATES PATENTS 2,761,633 9/56 Sindzinski 243--38 3,107,006 10/63 Myotte 205-3 CHARLES W. LANHAM, Primary Examiner.

Claims (1)

1. IN A DRAWBENCH OF THE TYPE INCLUDING A DRAWING DIE, A TRACK STRUCTURE EXTENDING PARALLEL TO THE AXIS OF SAID DIE ON ONE SIDE THEREOF, AND A DRAW CARRIAGE MOVABLE ALONG SAID TRACK STRUCTURE FOR PULLING WORKPIECES THROUGH THE DIE; THE IMPROVEMENT OF MEANS FOR PREVENTING DAMAGE TO THE WORKPICES BY VIRTUE OF ITS BEING PROPELLED FORWARDLY AS ITS TRAILING END LEAVES THE DIE, THE SAID MEANS COMPRISING A PAIR OF MEMBERS POSITIONED ADJACENT SAID DIE ABOVE AND BELOW THE DIE AXIS AND ARRANGED TO FRICTIONALLY ENGAGE OPPOSITE SIDES OF THE WORKPIECE DURING A DRAWING OPERATION WHEN THE DRAW CARRIAGE MOVES AWAY FROM SAID DIE, AND MEANS FOR MOVING SAID MEMBERS AWAY FROM THE CENTRAL AXIS OF SAID DIE WHEN THE DRAW CARRIAGE APPROACHES THE DIE TO PERMIT THE DRAW CARRIAGE TO ENGAGE A WORKPIECE PREPARATORY TO A WINDING OPERATION.

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