US3210983A

US3210983A - Drawbench apparatus

Info

Publication number: US3210983A
Application number: US320454A
Authority: US
Inventors: Sheldon E Wells
Original assignee: Mannesmann Meer Inc
Current assignee: Mannesmann Meer Inc
Priority date: 1963-10-31
Filing date: 1963-10-31
Publication date: 1965-10-12
Anticipated expiration: 1982-10-12

Description

Oct. 12, 1965 s. E. WELLS 3,210,983

DRAWBENCH APPARATUS Filed Oct. 31, 1963 2 Sheets-Sheet 1 U1 OI m (I) 0 If) m l-L Q E w 05 t0 m N L N w E (D m Z O N (1) '1 w o h) a v H In 5 Z O N (Q INVENTOR.

m g SHELDON E. WELLS l B E l W his ATTORNEY.

Oct. 12, 1965 s. E. WELLS DRAWBENCH APPARATUS Filed Oct. 31, 1965 2 Sheets-Sheet z &

SHELDON E. WELLS if/W his ATTORNEY.

q: INVENTOR. .9 LL

United States Patent 3,210,983 DRAWBENCH APPARATUS Sheldon E. Wells, Youngstown, Ohio, assignor to Mannesmann-Meer, Inc., Youngstown, Ohio, a corporation of Pennsylvania Filed Oct. 31, 1963, Ser. No. 320,454 11 Claims. (Cl. 72291) This invention relates to drawbenches adapted to draw one or more tubes or the like through a corresponding number of dies. More specifically, the invention relates to apparatus for preventing damage to newly-drawn tubes as a result of their being propelled forwardly 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, such as a tube, is drawn in order to elongate it and reduce its diameter. In the drawing operation, the end-s of tubes to be drawn are passed through a corresponding number of dies 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 on one side thereof. In the drawing operation, the draw carriage is forced along its track structure away from the die, thereby pulling the tubes through the dies. in the usual case, the draw carriage is driven by means of an electric motor or fluid motor, connected to the cartriage through a chain or cable drive arrangement.

It is :a common occurrence in the drawing of tubes for the same to jump forwardly with considerable force as their trailing ends leave the dies, the reason being that the tubes are under substantial tension during the drawing operation, and the sudden release of such tension is accompanied by a release of energy which propels the tubes forwardly with considerable force. The action is somewhat analogous to that occurring when one end of a stretched elastic band is released and snaps forwardly toward the other end. In the drawing of long, slender tubes of thin-walled section this condition is a particularly serious problem in that the forward ends of the tubes are driven against the draw carriage and are often buckled and rendered unsuitable for a subsequent drawing operation, or partially so. That is, when a long slender tube is driven against the draw carriage, shock waves develop along its length. If these waves are such as to produce bends in the tube of such magnitude as to exceed its elastic limit, permanent deformation will result, thereby producing the buckled or dog-legged condition mentioned. This condition may be severe enough to render the tube unsuitable for further processing .and, even if minor, makes the stocking or piling of the tubes diificult for reasons which will be apparent fro-m a consideration of the bent condition of the tubes.

In the past, various schemes have been proposed in an attempt to prevent buckling or dog-legging of the forward ends of the tubes. One such proposal calls for shock absorbers on the draw carriage designed to absorb the kinetic energy of the tubes as they jump forwardly at the completion of a draw. Another proposal utilizes inclined planes or deflectors designed to direct the tube down beneath the draw carriage where it can expend its energy by moving along a raceway beneath the draw carriage track. Neither of these systems, however, is completely successful in eliminating a dog-legged condition and raise auxiliary problems in the design of the draw carriage, tube receiving trough or other parts of the drawbench.

As an overall object, the present invention seeks to provide new and improved apparatus for preventing damage to the forward ends of newly-drawn tubes at the completion of a drawing operation, which apparatus over- 3,210,983 Patented Oct. 12, 1965 comes the aforementioned and other disadvantages of prior art systems of this type.

More specifically, an object of the invention is to provide means in a drawbench for laterally restraining a tube as it is being drawn, whereby the restraining means will prevent waves from developing in the tube and hence, permanent deformation resulting in dog-legging.

Still another object of the invention is to provide means in drawbench apparatus for evenly and uniformly stacking newly-drawn tubes in a receiving bin or the like to facilitate their further processing.

In accordance with one embodiment of the invention, a plurality of panel devices, each of normally separated upper and lower parts, are spaced along the drawbench track structure and designed such that their upper and lower parts come together or close in succession behind the draw carriage as it moves down the track during a drawing operation. As each of the panel devices closes, it envelops or surrounds, but does not touch, the tubes being drawn so as to provide a plurality of openings in successive panel devices through which the tubes pass. At the completion of the drawing operation when the tubes giump forwardly .and strike the draw carriage, the openings in the panel devices will serve to laterally restrict the tubes. Consequently, since the tubes cannot now be deflected laterally in any appreciable amount by the development of shock waves, they cannot bend to an extent exceeding their elastic limit and permanent bends or dog legs cannot develop. Finally, when the draw carriage returns to the dies following a drawing operation, the upper and lower parts of all panel devices separate to permit the carriage to move toward the dies preparatory to a succeeding drawing operation.

Preferably, the upper and lower parts of each panel device are mounted for pivotal movement about a common horizontal axis in what might be termed a scissors arrangement with the parts being rotated about their common axis int-o abutment as they are passed by the draw carriage during the drawing operation, and rotated in opposite directions so as to separate and permit the draw carriage to pass during its return stroke. As will be seen, downward movement of the lower part of each panel device deposits the newly-drawn tubes onto an inclined run-out table where they roll into a neat bundle preparatory to further processing. Thus, contrary to most prior art drawbenches wherein difliculty is experienced in attempting to pile the newly-drawn tubes in neat bundles, the present invention has the auxiliary advantage in that it eliminates such problems.

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 partially broken-away top view of the dies, track structure, draw carriage and associated apparatus of the drawbench of the invention;

FIG. 2 is a side view of the apparatus shown in FIG. 1;

FIGS. 3A and 3B show the manner in which a drawn tube is bent or dog-legged due to the release of kinetic energy at the completion of a draw; and

FIG. 4 is a cross-sectional view taken substantially along line TVW of FIG. 1, showing in detail one of the panel devices of the invention in association with the pneumatic and electrical control system therefor.

Referring now to the drawings, and particularly to FIGS. 1, 2 and 4, the numeral 10 represents generally the main framework of a draw bench assembly which is comprised of a plurality of frame sections 12. One of said frame sections is shown in detail in FIG. 4 and comprises a castingof generally C-shaped form having a lower portion 14, an upstanding portion 16 and an upper cantilever beam section 18. At the forward end of the beam section 18 is a downwardly-depending integral portion 20 which carries at its lower end a track support 22. The support 22 is one of a complementary pair, a second support 24 being carried by the upstanding portion 16, as shown.

In the complete drawbench assembly as shown in FIGS. 1 and 2, there are a plurality of frame sections 12 mounted in spaced relation. Carried by the plurality of

supports

22 and 24 of such frame sections are spaced tracks 26 and 28 (FIG. 4) which support and guide a draw carriage 30 for longitudinal movement throughout the length of the drawbench, as will be subsequently developed herein.

Below each of the track supports 22 and 24, and extending through openings 32 in the lower portion 14 of each frame section 10 (FIG. 4) are guiding and supporting

channels

34 and 36 for a pair of spaced

draw chains

38 and 40 which are employed to draw the carriage 30 along its guided path on the

tracks

26 and 28 during a drawing operation. The

draw chains

38 and 40 are connected to the forward end of the carriage 30 as at 39 and to its other end through an equalizer bar 41. Suitable sprockets 42 (see FIG. 2) are provided at each end of the respective traverses of the

chains

38 and 40, and around which the chains articulate.

At the trailing end of the drawbench assembly as viewed in FIGS. 1 and 2 is a heavy-duty drive motor 44 and gear reducer 46, the latter of which has driving connection with the sprockets 42 at the right-hand end of the assembly to thereby impart a driving force to the

chains

38 and 40. Preferably, the motor 44 is of the reversible type such that it may rotate the sprockets 42 to move the draw carriage 30 to the right during the drawing operation or to the left during the return stroke of the draw carriage. At the left end of the drawbench assembly 10 shown in FIGS. 1 and 2 is a die block 48 provided with a plurality of dies positioned in side-by-side relationship and through which tubes 50 are drawn.

In the drawing operation, the tubes to be drawn are loaded onto a rack 52 extending along the drawbench frame 10 at the forward portion thereof and supported on the tops of the cantilever beam portions 18 of each frame section 12 as shown in FIG. 4. Thereafter, the tubes are loaded onto mandrels, not shown herein, but positioned to the left of the die block 48 in FIGS. 1 and 2. After the tubes are loaded onto the mandrels, their swaged or reduced diameter ends are inserted through the openings in the dies and gripped by gripper jaws on the draw carriage 30, such gripper jaws being hereinafter described in greater detail. After the forward ends of the tubes are thus gripped by the gripper jaws, the motor 44 is actuated to force the draw carriage 30 away from the die block 48, thereby pulling the tubes 50 through the dies while reducing their diameters and increasing their lengths.

The operation of the drawbench is schematically illustrated in FIGS. 3A and 3B. In FIG. 3A, a tube 54 being drawn through a die 56 is in substantial tension and has its forward swaged or reduced diameter end 58 engaged by

grip bits

60 and 62 carried on the draw carriage, schematically illustrated at 64. The

grip bits

60 and 62 are mounted in converging guideways such that as the draw carriage 64 is pulled away from the die 56, the

bits

60 and 62 are forced into gripping relationship with the reduced diameter end 58.

The completion of the drawing operation is illustrated in FIG. 3B when the trailing end of the tube 54 passes through the die 56. As was explained above, passage of the trailing end through the die 56 is accompanied by a release of energy which propels the tube forwardly, thereby moving the

grip bits

60 and 62 backwardly and releasing the forward reduced diameter end 58 of the tube. This causes the tube 54 to strike the draw carriage 64. When this occurs,shock waves are developed in the tube 54 as illustrated in FIG. 3B; and if the magnitude of these shock waves is great enough, and it often is, the elastic limit of the tube 54 will be exceeded whereby perma nent bends or dog-legs will be produced in the tube, usually at the forward end thereof. In other words, deformation occurs at the forward end of the tube, not ordinarily at its trailing end.

In accordance with the present invention, the development of shock waves and the possibility of permanent deformation is prevented by causing each tube to pass through a series of openings spaced along its length during the drawing operation so as to restrict it laterally. Apparatus for carrying forth the invention is shown in FIGS. 1, 2 and 4 and comprises a first plurality of separable panel and platform devices 66 at the forward end of the drawbench frame 10 as shown in FIGS. 1 and 2 and a second plurality of elevatable platform devices 68 at the trailing or left end of the frame structure 10 as viewed in FIGS. 1 and 2. The frame structure 10 may, therefore, be divided into Zone 1 along which platform devices 68 are spaced, and Zone 2 along which panel and platform devices 66 are spaced. The main requirement of Zone 1 is that it does not extend beyond the length of the shortest tube being drawn so that at least the forward end of every drawn tube will extend into Zone 2 before its trailing end snaps free of the die.

One of the separable panel devices is shown in FIG. 4 and comprises a pair of upper and

lower parts

70 and 72, respectively. Both

parts

70 and 72 are pivotally connected to a horizontal pin or axle 73 supported on the upright portions 16 of the frame sections 12 in a scissors-type arrangement. The lower part 72 comprises an arm having an upper platform 74 adapted to be rotated into position whereby the platform 74 is directly beneath the tubes 50 being drawn. The upper part 70, on the other hand, also comprises an arm which is movable from a position where it is at an angle to horizontal to a position where it is in a substantially horizontal plane with its major portion above the tubes being drawn.

Depending downwardly from the upper part 70 is a plate 76 having formed therein a plurality of U-shaped openings 78 adapted to fit over the tubes being drawn with the lower edge 80 of the plate 76 being in abutment with the upper surface of platform 74. In order to raise and lower the upper part 70 about pin 73, a pneumatic cylinder 82 is provided having its piston rod 84 connected through a clevis arrangement 86 to an upstanding bracket 88 on the part 70. The other end of the pneumatic cylinder 82 is pivotally connected at 90 to an I-beam 92 which extends along the entire drawbench frame 10 as shown in FIG. 1.

In a somewhat similar manner, the lower part 72 is actuated by means of a pneumatic cylinder 94 having its one end pivotally connected at 96 to a second continuous I-beam 98 and its piston rod 100 connected through a clevis arrangement 102 to a downwardly-depending bracket 104 on the part 72. Both of the

parts

70 and 72 are constructed from welded plates and gussets, the details of which are unimportant as regards the present invention.

When the right ends of the

cylinders

82 and 94 are pressurized, the

parts

70 and 72 will be caused to pivot about pin 73 into abutting relationship with the lower edge 80 of plate 76 in abutment with the upper surface of platform 74. Pressurization of the

cylinders

82 and 94 in the opposite sense will cause the

parts

70 and 72 to separate and assume positions at angles to the horizontal. With the part 72 in its lowermost position shown in FIG. 4, the platform 74 forms a common plane with surfaces 106 on the lower portions 14 of the frame sections 12 to thereby provide an inclined run-out table for the newly-drawn tubes.

The plurality of platform devices 68 at the forward end of the main drawbench frame 10 in Zone 1 are sim;

ilar to the arrangement shown in FIG. 4, except that only the lower part 72 is provided to support the tubes being drawn. It will be appreciated that in order for the draw carriage 30 to pass along the

tracks

26 and 28, the

parts

70 and 72 must be the positions shown in FIG. 4. Consequently, the

cylinders

82 and 94 can be pressurized to close the

parts

70 and 72 only during a drawing operation and after the draw carriage 30 has passed the position of a particular platform device 68 in Zone 1 or panel device 66 in Zone 2 along the drawbench frame 10. In the drawing operation, and assuming that the draw carriage 30 is adjacent the die block 48 at the beginning of a drawing operation, the motor 44 will be energized to pull the draw carriage away from the die block 48, thereby pulling the tubes 50 through the dies. As the draw carriage passes each platform device 68 in Zone 1, its associated pneumatic cylinder 94 will be pressurized to elevate the part 72 shown in FIG. 4 and thereby move the platform 74 up into abutting relationship beneath the tubes being drawn. Likewise, as the draw carriage 30 passes each of the panel devices 66 in Zone 2 as it moves away from the die block 48, the

cylinders

82 and 94 will be pressurized to close the upper and lower parts 70 .and 72 shown in FIG. 4 whereby the tubes will be enveloped within an opening defined by the surface of platform 74 and the periphery of an associated one of the U-shaped slots 78. These positions are shown in dotted outline in FIG. 4. At the completion of the drawing operation when the tubes jump forwardly due to the release of kinetic energy, the U-shaped slots 78 of each panel device and the associated platform 74 will prevent any substantial lateral deflection of the tubes 50, thereby also preventing the formation of shock waves in the tubes exceeding their elastic limits.

After all of the tubes have been drawn, the draw carriage is stopped, and the

cylinders

82 and 94 pressurized to separate the upper and

lower parts

70 and 72 of each panel device 66 in Zone 2. Similarly, the cylinders 94 associated with the platform devices 68 in Zone 1 are pressurized to lower their associated platforms 74. In this process, it will be appreciated that the previouslydrawn tubes will roll from the platforms 74 onto the surfaces 106 and thence into a receiving bin, not shown, to the left of the frame sections 12 shown in FIG. 4. In this manner, the arrangement facilitates a side-by-side and parallel relationship of the newly-drawn tubes such that when the platforms 74 move downwardly, the tubes will simply roll into a neat bundle in the aforesaid receiving bin preparatory to a succeeding drawing operation.

Circuitry for controlling the panel devices 66 and platform devices 68 is also shown in FIG. 4 and includes a reversing valve 108 having one port 110 connected to a source of air under pressure, not shown, and another port 112 extending to the atmosphere. One delivery port of the valve 108 is connected through conduit 114 to the forward ends of the

pneumatic cylinders

82 and 94; while the other delivery port is connected through conduit 116 to the rear ends of the

cylinders

82 and 94. With the valve 108 in the position shown in FIG. 4, the conduit 114 will be pressurized to thereby cause the upper and

lower parts

70 and 72 to separate with the conduit 116 being connected to the atmosphere through port 112. Reversal of the valve 108 will effect the opposite result with the conduit 116 being pressurized to cause the upper and

lower parts

70 and 72 to converge until the edge 80 of the upper part 70 is in abutment with the platform 74 of the lower part 72. Of course, in the case of the plat form devices 68 in Zone 1, the valve 108 is connected to cylinder 94 only.

The valve 108 is controlled by two solenoids 118 and 120. Provided along the main drawbench frame beyond each of the panel devices 66 is a one-way limit switch 122 which will be actuated only upon movement of the draw carriage away from the die block 48. The

. locations of switches 122 for Zone 2 are shown in FIG. 1.

Let us assume, for example, that the draw carriage has just passed the frame section 12 shown in FIG. 4 and has actuated the limit switch 122. Actuation of limit switch 122 closes contacts 124 to thereby energize the relay 126. Relay 126 is held closed after actuation of the limit switch 122 through a circuit including contacts 128 on relay 126 and normally closed contacts 130 on a pushbutton switch 132. Thus, as the draw carriage 30 passes each panel device 66, its associated limit switch 122 will be closed to energize relay 126. Energization of relay 126, in turn, closes contacts 134 to energize solenoid 118 and position valve 108 such that conduit 116 is pressurized to force the upper and

lower parts

70 and 72 together. The operation is the same for the platform devices 68 with the exception that only the lower part 72 and cylinder 94 are employed.

At the completion of the drawing operation when all tubes have passed through the dies, they will remain within the U-shaped slots 78. Thereafter, the pushbutton 132 is depressed. This pushbutton may, for example, be that utilized to reverse the motor 44 and return the draw carriage 30 to the die block 48. As the pushbutton 132 is depressed, it opens contacts 130, thereby breaking the holding circuit for relay 126 and deenergizing solenoid 118. At the same time, depression of pushbutton switch 132 closes contacts 136 to energize relay 138. When relay 138 is energized, it is held energized through a holding circuit including normally open contacts 140 on the relay 138 and contacts 142 on limit switch 122, which remain closed until the subsequent drawing operation for the reason that the limit switch 122 is not actuated upon the return stroke of the draw carriage. Energization of relay 138 also closes contacts 144, thereby energizing solenoid 120 to reverse the valve 108 whereby conduit 114 is now pressurized to cause the upper and

lower parts

70 and 72 to separate. Although the circuitry shown in FIG. 4 is for one panel device only, it will be appreciated that the leads 146 on pushbutton switch 132 are connected to the relays for all of the panel devices 66 and platform devices 68 spaced along the main track structure 10 such that they will open simultaneously to permit the tubes on platforms 74 to roll into the aforesaid receiving bin and permit the draw carriage to pass backwardly toward the die block 48. During the next successive drawing operation, each limit switch 122 is actuated in succession after the draw carriage passes its associated platform device or panel device to thereby again provide a plurality of openings through which the tubes must pass and which prevent any substantial lateral displacement of the tubes.

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 this respect, it will be apparent that cables can be substituted for the

chains

38 and 40 within the skill of the art.

I claim as my invention:

1. In a drawbench of the type having 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 and including jaws which grip the forward end of a workpiece projecting through the die as it moves away from the die; the improvement of means for preventing damage to the workpiece as it is propelled forwardly at the completion of a draw due to the release of kinetic energy and the development of shock waves along its length, comprising rigid means for completely circumferentially enveloping at least a portion of the workpiece between said jaws and the die when the draw carriage moves away from the die to thereby prevent the development of said shock waves, the enveloping means being out of substantial frictional engagement with the workpiece while it is under tension during a drawing operation.

2. In a drawbench of the type having 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 and including jaws which grip the forward end of a workpiece projecting through the die as it moves away from the die; the improvement of means for preventing damage to the workpiece as it is propelled forwardly at the completion of a draw due to the release of kinetic energy and the development of shock waves along its length, comprising a plurality of substantially rigid devices spaced along the track structure for enveloping completely circumferentially the workpiece between said jaws and the die when the draw carriage moves away from the die to thereby prevent the development of said shock waves, the rigid devices being out of substantial frictional engagement with the workpiece while it is under tension during a drawing operation.

3. The improvement of claim 2 wherein said plurality of substantially rigid devices are movable from points removed from the axis of the die to points adjacent the axis of the die, and including means for moving said devices toward the axis of the die when the draw carriage moves away from the die and for moving the devices away from the axis of the die when the draw carriage moves toward the die.

4. In a drawbench of the type having 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 and including jaws which grip the forward end of a workpiece projecting through the die as it moves away from the die; the improvement of means for preventing damage to the workpiece as it is propelled forwardly at the completion of a draw due to the relase of kinetic energy and the development of shock waves along its length, comprising a first member positioned along the track structure and movable from a position removed from the central axis of the die to a position adjacent a workpiece being drawn, a second member positioned along the track structure on the side of the die axis opposite said first member and movable from a position removed from the central axis of the die to a position adjacent a workpiece being drawn and in substantial abutment with said first member, a generally U-shaped opening in the abutting surface of at least one of said members to provide an opening which envelops but does not substantially frictionally engage the workpiece when the members are in abutment and the workpiece is under tension during a drawing operation, means for moving said members into abutment when the draw carriage moves away from the die and after it passes the position of the members along the track structure, and means for separating said members when the draw carriage moves toward the die and before it passes the position of the members along the track structure.

5. In a drawbench of the type having 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 and including jaws which grip the forward end of a workpiece projecting through the die as it moves away from the die; the improvement of means for preventing damage to the workpiece as it is propelled forwardly at the completion of a draw due to the release of kinetic energy and the development of shock waves along its length, comprising a first plurality of members positioned along the track structure, each of said first members being movable from a position removed from the central axis of the die to a position adjacent a workpiece being drawn, a second plurality of members positioned along the track structure on the side of the axis of the die opposite said first members, each of said second members being movable from a position removed from the central axis of the die to a position adjacent a workpiece being drawn and in substantial abutment with an associated one of said first members, a generally U-shaped opening in the abutting surface of at least one member of each associated pair of abutting members to provide an opening which envelops but does not substantially frictionally engage the workpiece when the members are in abutment and the workpiece is under tension during a drawing operation, means for moving each pair of associated members into abutment when the draw carriage moves away from the die and after it passes the position of each pair of associated members along the track structure, and means for moving said members away from the central axis of the die when the draw carriage moves toward the die and before it passes the position of the associated pair of members along the track structure.

6. In a drawbench of the type having 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 and including jaws which grip the forward end of a workpiece projecting through the die as it moves away from the die; the improvement of means for preventing damage to the workpiece as it is propelled forwardly at the completion of a draw due to the release of kinetic energy and the development of shock waves along its length comprising a first member positioned along the track structure and pivotally movable about a generally horizontal axis from a position where it is at an angle to horizontal beneath the workpiece to a position where it is in a generally horizontal plane directly beneath the workpiece, a second member spaced along the track structure at the position of said first member and pivotal about a generally horizontal axis, said second member being pivotally movable from a position where it is at an angle to horizontal above the workpiece to a position where it is in a generally horizontal plane with its major portion above the workpiece and having a lower surface in abutment with said first member, and a generally U-shaped slot in said second member adapted to fit over the workpiece when the second member is in its generally horizontal position whereby the slot in the second member, in combination with the first member, will envelop but not substantially frictionally engage the workpiece when the workpiece is under tension during a drawing operation, means for forcibly rotating the first and second members into their horizontal positions when the draw carriage moves away from the die and after it passes the first and second members, and means for forcibly rotating the first and second members into their positions at angles to the horizontal when the draw carriage moves toward the die and before it passes the first and second members.

7. The improvement of claim 6 wherein said first and second members are pivotal about a common horizontal axis, and wherein the means for forcibly rotating the members about their common horizontal axis includes fluid cylinder means operatively connected to the members and limit switch means adjacent the track structure adapted to be actuated by passage of said draw carriage.

8. In a drawbench of the type having 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 and including jaws which grip the forward end of a workpiece projecting through the die as it moves away from the die; the improvement of means for preventing damage to the workpiece as it is propelled forwardly at the completion of a draw due to the release of kinetic energy and the development of shock waves along its length comprising a first plurality of members positioned along the track structure, each of said first members being pivotally movable about a generally horizontal axis from a position where it it at an angle to horizontal beneath the workpiece to a position where it is in a generally horizontal plane directly beneath the workpiece, a second plurality of members spaced along the track structure, each of said second members being in alignment with an associated one of said first members and pivotally movable about a generally horizontal axis from a position where it is at an angle to horizontal above the workpiece to a position where it is in a generally horizontal plane with its major portion above the workpiece and having a lower surface in abutment with an associated one of said first members, and a generally U-shaped slot in each of said second members adapted to fit over the workpiece when each second member is in its generally horizontal position whereby the slot in the second member, in combination with its associated first member, will envelop but not substantially frictionally engage the workpiece when the workpiece is under tension during a drawing operation, means for forcibly rotating each of said associated first and second members into their horizontal positions when the draw carriage moves away from the die and after it passes each of said first and second associated members, and means for forcibly rotating each said associated first and second members into their positions at angles to the horizontal when the draw carriage moves toward the die.

9. The improvement of claim 8 and including an inclined run-out table beneath the track structure which lies in a common plane with the upper surfaces of said second members when they are in their positions at an angle to horizontal.

10. In a drawbench of the type having 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 and including jaws which grip the forward end of a workpiece projecting through the die as it moves away from the die; the improvement of means for preventing damage to the workpiece as it is propelled forwardly at the completion of a draw due to the release of kinetic energy and the development of shock waves along its length, comprising a plurality of scissors-like mechanisms having upper and lower arms pivotal about a horizontal axis at one side of the track structure and adapted to close and restrain lateral movement of a workpiece being drawn without substantially frictionally engaging the same when the draw carriage moves away from the die during a drawing operation, said scissors-like devices each being adapted to open to permit the draw carriage to pass therethrough upon movement of the draw carriage toward the die.

11. In a drawbench of the type having 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 and including jaws which grip the forward end of a workpiece projecting through the die as it is moved away from the die; the improvement of means for preventing damage to the workpiece as it is propelled forwardly at the completion of a draw due to the release of kinetic energy and the development of shock waves along its length, comprising a first plurality of platform devices spaced along the track structure at the end of the track structure nearest the die for supporting a drawn workpiece against gravity and a second plurality of devices spaced along the track structure beyond the first plurality of platform devices for enveloping the workpiece without substantially frictionally engaging the same as it is being drawn to thereby prevent the development of shock waves in the forward end of a workpiece enveloped by said second plurality of devices.

References Cited by the Examiner UNITED STATES PATENTS 3,107,006 10/63 Myotte 205--3 3,175,385 3/65 Mitchell 72-281 CHARLES W. LANHAM, Primary Examiner,