US3587280A

US3587280A - Method and apparatus for pulling extrusions from an extrusion press

Info

Publication number: US3587280A
Application number: US426817A
Authority: US
Inventors: Max Engelhardt; Kurt F Ziehm Jr
Original assignee: XPRESS AUTOMATION Inc
Current assignee: XPRESS AUTOMATION Inc
Priority date: 1965-01-21
Filing date: 1965-01-21
Publication date: 1971-06-28
Anticipated expiration: 1988-06-28
Also published as: DE1602398A1; GB1129221A

Abstract

THERE IS DISCLOSED AN EXTRUSION PULLER INCLUDING A GRIPPER ASSEMBLY SLIDABLE ON A RUNOUT TABLE AWAY FROM AND TOWARD A DIE OF AN EXTRUSION PRESS. THE GRIPPER ASSEMBLY INCLUDES A PLURALITY OF INDIVIDUAL GRIPPER ELEMENTS ENGAGEABLE WITH ONE OR MORE EXTRUSION SURFACES OF THE EXTRUSIONS. WHEN THE GRIPPER ELEMENTS ARE TRIGGERED INTO ENGAGEMENT WITH THE EXTRUSION SURFACES, THE EXTRUSIONS ARE GRIPPED AND THE GRIPPER ASSEMBLY IS DRIVEN TOWARD THE END OF THE RUNOUT TABLE. WHEN THE GRIPPER ASSEMBLY IS NEAR THE END OF THE RUNOUT TABLE THE GRIPPER ASSEMBLY IS OPERATED BY A CAM TO RELEASE THE EXTRUSIONS AND THE GRIPPER ELEMENTS OF THE GRIPPER ASSEMBLY ARE RESET BY THE CAM. UPON RELEASE OF THE EXTRUSIONS, THE FORWARD MOTION OF THE EXTRUSIONS IS ARRESTED, THE GRIPPER ASSEMBLY IS AUTOMATICALLY RETURNED TO ITS REST POSITION NEAR THE DIE WHEN THE EXTRUSIONS HAVE CLEARED THE RUNOUT TABLE. THE GRIPPER ASSEMBLY IS STARTED AND STOPPED BY A CLUTCH AND BRAKE ARRANGEMENT.

Description

United States Patent 2,914,170 11/1959 Kent 3,118,539 1/1964 l-larwood... 3,147,268 11/1964 Anderson Inventors Mu Bagelhsrdt Kurt l Ziehrn, Jr lensenvilb, 111. 426,017

Jan. 21, 1965 June 28, 1971 Xpress Automation, Inc., Chicago. Ill.

Appl. No. Filed Patented Assignee Int. Cl

References Cited UNITED STATES PATENTS Assistant ExaminerR0bert M. Rogers Attorney-Joseph .1. Grass ABSTRACT: There is disclosed an extrusion puller including a gripper assembly slidable on a runout table away from and toward a die of an extrusion press. The gripper assembly includes a plurality of individual gripper elements engageable with one or more extrusion surfaces of the extrusions. When the gripper elements are triggered into engagement with the extrusion surfaces, the extrusions are gripped and the gripper usembly is driven toward the end of the runout table. When the gripper assembly is near the end of the runout table the gripper assembly is operated by a cam to release the extrulions and the gripper elements of the gripper assembly are reset by the cam. Upon release of the extrusions, the forward motion of the extrusions is arrested, the gripper assembly is automatically returned to its rest position near the die when the extrusions have cleared the runout table. The gripper assembly is started and stopped by a clutch and brake arrangement.

PATENTED JUN28 I971 SHEET 2 UF 4 METHOD AND APPARATUS FOR PULLING EXTRUSIONS FROM AN EXTRUSION PRESS This invention relates to a method of pulling and handling extrusions and to apparatus for carrying out the method.

In the extrusion art, it is known to charge a heated billet of extrudable material into a container of an extrusion press. Upon completion of the charging, the front end of the billet is in abutment with the rear face of the extrusion die. As the diameter of the billet in the container has about the same diameter as the cylindrical opening of the container, a ram of the extrusion press acting against the rear face of the billet causes the billet material to be extruded through die openings of the extrusion die. The extrusion is passed onto a runout table or equivalent supporting means as it is being formed. Sometimes an extrusion pulling apparatus is used to assist the extrusion process. When substantially the entire billet has been extruded through the die, the small remaining part or butt is separated from the trailing marginal end or tail of the extrusion in the die by passing a shear across the rear face of the die.

In accordance with the method of the invention, a small amount of billet material is extruded through the die to form one or more extruded ends, corresponding in number to the number of openings in the die. This extruded end, or ends, as the case may be, can be relatively short but should be long enough to conveniently gripped. Extruded ends can be gripped by a gripper mechanism, situated at a rest position beyond the die and at least slightly beyond the extruded ends. As the gripper mechanism is spaced from the front end of the press ahead of the die the extruded ends can be visually observed. Should it happen that the extruded ends, for some reason, extend out beyond the die so as to be difficult to grip, they can be manually oriented. Should the die be unbalanced so that one or more of the extrusions do not extend sufficiently beyond the die to be easily gripped, this will be visually readily apparent. When the extruded ends are ready to be gripped, a gripper mechanism can be moved, and in particular jogged, into gripping position with the extruded ends. The gripper mechanism can slide on a runout table which extends outwardly or forwardly beyond the die for a substantial distance. When the gripper mechanism is in gripping position, the gripper mechanism is actuated to grip the extrusions and, if desired, can be automatically operated to move forwardly. The gripper mechanism is moved forwardly along, and specifically on, the runout table, and sufficient force is exerted on the gripper mechanism to pull the extrusions forwardly by their leading marginalends to maintain the extrusions substantially straight. Assuming that the billet is almost entirely extruded before the gripper mechanism has moved to near the end of the runout table, the ram of the press will cease its movement toward the die. The gripper mechanism will stop because the trailing marginal end or tail of the extrusion is still in the die and attached to the butt and the pulling force is insufficient to separate the tail from the butt. A shear is then passed across and in contact with the rear face of the die to shear the butt from the trailing marginal end. It is preferred to exert a greater force on the leading marginal end of the extrusion by means of the gripper mechanism immediately upon completion of the shearing off of the butt. In accordance with the invention, this greater force is greater than the force exerted on the leading marginalend when the extrusion is being made, and yet jerking action on the extrusion is avoided. It is evident that once the butt has been sheared from the tail or tails, only frictional forces hold the tail or tails from being pulled out of the die opening or openings. The'tails of the extrusions can thus be automatically completely removed from the die openings. The greater pulling force speeds the gripper mechanism and the extrusion or extrusions which it is pulling toward the end of the runout table after the trailing marginal ends have left the die. The extrusions have considerable momentum as they can be quite long, by way of example not limitation, 100 feet. The method of the invention provides for arresting the forward movement of the extrusions when they have reached a predetermined position along the runout table.

Immediately after the gripper mechanism is actuated to release the leading marginal ends of the extrusions, the forward movement of the extrusions is arrested, in particular, by applying a clamping force to the leading forward ends. The arresting force preferably yields in the direction of extrusion travel to prevent the extrusions from buckling. As the gripper mechanism substantially simultaneously releases the gripper mechanism from gripping engagement and effects resetting, the gripper mechanism is ready or preset for future triggering.

When the gripper mechanism has cleared the leading ends of the extrusions, the forward motion of the gripper mechanism is arrested. At about the time the gripper mechanism has cleared the ends of extrusions and the forward movement of the extrusions on the runout table has been arrested, the extrusions are transferred off the runout table, for example by transverse conveying means. Specifically the extrusions are lifted slightly to clear the runout table and the lifted extrusions are conveyed transversely off the runout table. Completion of operation of the conveyingmeans is sensed and thereupon not only is the gripper mechanism able to return to its rest position near the die but, as is preferred, the movement of the gripper mechanism in the rearward direction toward the rest position is automatically commenced. So long as the completion of the transverse transferring movements of the conveying means is not complete return of the gripper mechanism is prevented.

As the gripper mechanism moves rearwardly along the runout table, actuation of arresting means capable of providing the arresting force is prevented. The gripper mechanism is sped rearwardly to the rest position where its movement is arrested.

If the billet material has not been substantially entirely extruded by the time the gripper mechanism is actuated to release the leading marginal ends of the extrusions and the clamping action or force is applied to the leading marginal ends, extrusion of additional material is interrupted and the extrusions are severed a sufficient distance beyond the die to enable gripping by the gripper mechanism upon its return to gripping position near the die.

Reference is now made to the accompanying drawings which illustrate apparatus for carrying out the method of the invention, in which:

FIG. I is a top plan view of apparatus for carrying out the method of the invention and showing a fragmentary portion of an extrusion press and partly broken away portions of a runout table and a transverse conveyor;

FIG. 2 is a side elevational view of apparatus illustrated in FIG. 1;

FIG. 3 is a perspective view showing a gripper mechanism in gripping engagement with a plurality of extruded ends;

FIG. 4 is a sectional view showing gripper elements of the gripper mechanism in gripping engagement with an angleshaped extrusion;

FIG. 5 is a rear view, partly in cross section, of the gripper mechanism; I

FIG. 6 is a fragmentary sectional view taken along line 6-6 of FIG. 5;

FIG. 7 is a fragmentary view of a gripper mechanism showing an alternative form of gripper elements;

FIG. 8 is a fragmentary top plan view showing a portion of the runout table and transverse conveyor;

FIG. 9 is a transverse .view showing one of the supporting and conveying assemblies of the transverse conveyor;

FIG. 10 is a sectional view taken along line 10-10 ofFIG. 9;

FIG. 11 is a side elevational view of the gripper mechanism and actuating cam;

FIG. 12 is a side elevational view showing an extrusion arresting mechanism; and

FIG. 13 is a circuit diagram for the apparatus for carrying out theinvention.

Referring now to FIGS. I and 2 of the drawings, there is shown a fragmentary portion of an extrusion press generally indicated at 20. As is conventional, the extrusion press 20 insupport 24 for the die, positioned against the head 21, a ram 25 slidable in a cylindrical bore 26 in a container 27, which ram and container are movable away from and towards the die 22, and a piston-cylinder mechanism 28 which operates a shear 29. The container bore 26 is shown to receive a billet 30 composed of extrudable material. When the container 27 is moved horizontally away from the die sufficiently a billet 30 can be charged into the container bore 26 assuming the ram 25 has moved rearwardly (to the right in FIG. 2). The front face of the ram 25 exerts great force against the rear face of the billet-30 during the extrusion cycle of the press 20 so that the billet material is extruded through the die opening or openings 31. When the billet is almost entirely extruded, the forward movement of the ram 25 terminates and the container 27 and ram 25 are both moved rearwardly away from the die 22. The piston-cylinder mechanism 28 is then actuated to move the shear across and in contact with the rear face 23 of the die 22 to shear the butt from the leading trailing end of the extrusion in the opening 31 in the die 22. When the shearing off the butt is complete, the piston-cylinder mechanism 28 returns the shear 29 to its rest position shown in FIG. 2.

A runout table 32 extends outwardly or forwardly from the extrusion press 20. The extruded material which passes through the opening 3] can pass through an enlarged opening 33 in the support 24 and through an enlarged opening 34 in the head 21 and onto 'the runout table 32. The extrusion can slope downwardly onto the runout table 32 as best shown in FIG. 2. I

The runout table has legs 35 forming part of a frame generally indicated at 36. The frame supports blocks or sections 37 composed of a material having a low coefficient of friction and capable of withstanding elevated temperatures .such as those at which the extrusions exist immediately after being extruded. A suitable material is graphite but any other suitable material can be used.

A gripper mechanism generally indicated at 38 is movable along, and more specifically is slidable over and on the upper surface 39 of the sections 37 of the runout table 32. A rail 40 guides the gripper mechanism'38 straight forwardly and rearwardly. A cam 41mounted on the head 21 of the press 20 can actuate the gripper mechanism 38 to enable extruded ends 42 of the extrusions to be gripped. A cam 43 mounted along the runout table 32 a substantial distance from the press 20 can actuate the gripper mechanism 38 to release the leading marginal ends of the extrusions from gripping engagement and to reset the gripper mechanism 38.

A drive mechanism generally indicated at 44 is operable selectively to drive the gripper mechanism 38 forwardly and rearwardly. The drive mechanism 44, schematically illustrated as having a reversible electric motor 45 a commercially available electric clutch 46 of the eddy current slip-clutch type, and an electric brake 47 (FIG. 13) housed in a box 48, drives a pulley 50 through a speed reducer 49. A cable 51 is trained around the pulley one and one-half times to insure good driving contact. Two vertically spaced idler pulleys 52 and 53 are rotatably mounted near the press 20. A vacuum actuated piston-cylinder mechanism 54 has a piston rod 55 which rotatably mounts a pulley 56. The piston-cylinder mechanism 54 is pivotally mounted to the frame 36 by a pin 57. The cable 51 is trained over the

pulleys

52, 56 and 53. A conduit 58 is connected to one end of the piston-cylinder mechanism 54 and to a pressure regulator 59. Constant vacuum is kept on the piston (not shown) of the piston-cylinder mechanism 54. The pulley 56 can thus yield in an outward direction when the force on the piston rod 55 increases, but the vacuum acting on the piston thereafter returns the pulley 56 to insure that the cable 51 is under proper tension. The ends 60 and 61 of the cable 51 are secured to the front and rear ends of the gripper mechanism 38. Thus, rotation of the pulley 50 in one direction will move the gripper mechanism 38 forwardly and rotation of the pulley 50 in the opposite direction will move the gripper mechanism rearwardly.

A substantial distance along the runout table 32, and in particular near the end of the runouttable 32, is a mechanism generally indicated at 62 for arresting the forward movement of extrusions, as best illustrated in FIG. 12. The arresting mechanism 62 is illustrated as having a piston-cylinder mechanism 63 pivotally mounted to a fixed support by a pivot pin 64. The piston-cylinder mechanism 63 has a piston rod 65 to which a clamping jaw 66 is securely attached. Means (not shown) prevents the jaw 66 from rotating. A stationary jaw or plate 67 in the runout table 32 is supported by the frame 36. The upper surface of the plate 67 is roughened and is substantially flush with the upper surface 39 of the runout table 32. A spring 68 urges the cylinder of the piston-cylinder mechanism 63 against yoke-shaped stop 69, so that the piston-cylinder mechanism 63 is approximately vertical. The piston-cylinder mechanism 63 is actuated by means of a conventional solenoid valve 70. The valve 70 is connected by two

flexible hoses

71 and 72 to opposite ends of the piston-cylinder mechanism 63. A conduit 70 is connected to the valve 70 and to a source of vacuum. The valve 70 effects communication between the conduit 70 and the hose 71 in one position and between the conduit 70' and the hose 72 in another position. When deenergized the valve 70 is in the one position and when energized the valve is in the otherposition.

In FIG. 1, there is illustrated a conveyor 73, which extends transversely to the longitudinal runout table 32. The conveyor 73 has lifting and transverse conveying assemblies 73'. A common shaft 74, fixedly mounts cams 75, one of which is shown in FIG. 9. The shaft 74 and the earns 75 are rotated upon actuation of the piston-cylinder mechanism 76. When the piston-cylinder 76 is actuated, the portion of each lifting and conveying element 77 which is situated in a gap 78 in the runout table 32 is raised to position above the upper surface 39 of the runout table 32 by the cam 75. Thereupon the shaft 79 is driven by means of a drive mechanism generally indicated at 80. Pinion gears 81 engage respective racks 82 of lifting and conveying assemblies 73'. Rotation of pinion gears 81 causes racks 82 and their respective lifting and conveying elements 77 to move transversely. When the rotation of shaft 79 is reversed by the drive mechanism 80, the lifting and conveying elements 77 move in the reverse direction. When the pistoncylinder mechanism 76 is operated in the reverse direction the lifting and conveying elements 77 can travel into the gaps 78 in the runout table and are in the position shown. Operation of the lifting and conveying assemblies 73 is accomplished by conveyor controls schematically illustrated in FIG. 13. As best shown in FIGS. 9 and 10, the lifting and conveying elements 77 slide in spaced angle-shaped guides 84 which are secured to a bracket 85 which is pivotally mounted on the shaft 79.

Gripper mechanism 38 is shown to have a frame formed by a baseplate 91 and

upstanding side plates

92 and 93 joined to the baseplate 91.

Side plates

92 and 93 pivotally mount a shaft 94. A cam follower 95 is secured to one end of the shaft 94 outwardly of the side plate 93. A stop bar 96 joins the rear end portions of the

side plates

92 and 93. A plurality of individual gripper elements 97 are free to pivot about the shaft 94. End gripper elements 98 are secured to the shaft 94 by keys 99. A bar 100 is welded to the end gripper elements 98. The

gripper elements

97 and 98 have arched lower camming surfaces 101 which are roughened for example by serrations 102 to facilitate gripping of the extrusions E. FIG. 4 illustrates an end gripper element 98 gripping an extrusion surface E" and an adjacent gripper element 97 gripping a higher extrusion surface E.

When the cam follower95 engages the cam 43, the cam follower 95 is actuated clockwise as viewed in FIG. 11. As the gripper elements 98 and bar 100 rotate as a unit with the shaft 94, the gripper elements 97 are also swung clockwise, The

'

gripper elements

97 and 98 are then latched into position inthe frame 90 has an elongated transverse slot 107. A vertical pin 108, secured to the pin 104, can move transversely in the slot 107. The pin 108 carries a roller 109. The cam follower 95 has a cam 110 engageable with the pin to exert a camming force. on the pin 104 during latching operation. When the pin 104 is latched against a shoulder 111, the gripper mechanism 38 is considered to be preset or set for future triggering. When the roller 109 engages thecam 41, the pin 104 is moved clear of the shoulder 111, and the

gripper elements

97 and 98 can move in a counterclockwise direction as viewed in FIG. 4 and 11 to grip extrusion surfaces of extrusions E even though these extrusion surfaces lie in planes at different elevations. The cam surface 91' at the rear end of bottom plate 91 serves to cam the leading ends of extrusions E onto the top surface of bottom plate 91 when the gripper mechanism 38 is moved relatively toward the leading ends of the extrusions.

A guide generally indicated at 112 straddles the rail 40 as best illustrated in FIGS. 3 and 5. A vertical portion 113 of the guide servesas a vane of a vane or proximity type switch, such as switch S8.

HO. 7 disclosesan alternative form of gripper elements for the gripper 38. Some of the gripper elements are the same as the gripper elements 97 are are designated'by 97a. Every third link along the shaft 94 is shown to be shorter than the links 97a and is designated by 97b. The profiles of the gripper elements 97a and 9711 are the same-,-the onlydifference being their lengths. lf desired, the-gripper elementscould be arranged so that every other gripper element is a shorter gripper element 97b, adjacent short gripper elements 975 would in such case be spaced apart by one gripper element 970. The gripper elements 970 are particularly useful when the extrusion surface to'be gripped does not extend too far aboutthe supporting surface of bottom plate 91, while the gripper elements 97bare particularly useful when the extrusion surface to be gripped is substantially above the supporting surface of the bottom plate 91.

Referring now to FIG. 13, there is shown a circuit diagram having leads 120 and 121 adapted to be connected to a source of electrical energy supply. A main switch 122is contained in a lead 123 which is connected to the lead 120.

Leads

124, 125, 126, 12-7, 128 and 129 are connected at opposite ends to leads 123 and 121. Lead 124 contains the switch S1 and a coil relay CR1 connected in series. Lead 125 contains switches 183 and 2S3 connected to each other in parallel and con-' nected 'in'series with a coil relay CR3. Lead 126 contains the switch S8 and a coil relay CR8 connected in series. Lead 127 containsthe switch S2 and a coil relay CR2 connected in series. Lead 128 contains switches 1S5'and 285 connected in parallel to each other and connected in series with a coil relay CR5. Lead 129 contains a switch S6 and a coil relay CR6 connected in series.

A lead 130 connected to the lead 123 is connected to leads 131 and !32. Lead 130 contains a switch 1CR and a stop-start all connected in series, joined to-the lead 121. The lead 145, connected to

junctions

148 and 149 contains normally open coil relay switch 2CR. Lead 146 contains a momentary switch 154.

The motor 45 is represented to have a forward coil 155 and a reverse coil 156. Forward coil 155 is connected to leads 157 and 158 which lead to a source of electrical energy supply, and the reverse coil 156 is connected to leads 158 and 159 which lead to a source'of electrical energy supply, with the lead 158 being common to the

coils

155 and 156. Lead 157 contains a switch 160 and lead 159 contains a switch 161.

The lead 138 is connected to leads 162 and 163. Lead 162 contains a switch S4 and a coil relay CR4 connected in series. The lead 162 is connected to the lead 121. Lead 163 contains a switch S9 and a coil relay CR9 connected in series. The lead 163 is connected to the lead 121.

A lead 164 is connected to the lead 123 and to

leads

165 and 166. A resistance coil 167 is connected to the lead 165 at a junction 168. A lead 169 is connected to the junction 168 and a junction 170. The lead 169 contains a normally open switch 17]. Lead 172, containing a normally closed switch 173, is connected to a movable contacter 174. The contacter 174 is capable of making contact at any place along resistance 167. The resistance 167 is connected to a lead 175, which in turn is connected to a lead 176. The'lead 176 is connected to a selenium bridge rectifier 177. The lead 176, containing two normally open switches 178 is also connected to the lead 121. A lead 179 containing coil 180 of the clutch 46 is also connected at each end to the rectifier 177.

The lead 166 is connected at a junction 18] to

leads

182 and 183. The lead 166 contains a normally closed coil relay switch 6CR. Thelead 183 is connected to the lead 182 at a junction 185. The lead 182, connected to the junctions 181 junction 140 in lead 136. The junction 140 lies between the

junctions

137 and 139. The lead l35'contains a normally open coil relay switch 8CRa. A lead 141 containing a forward coil relay FCR and two normally closed switches 142 is connected to the junction 139 and the lead 121. The lead 136 contains a momentary switch 144.

The lead 132 is connected to leads 145, 146 and 147 at a junction 148. The lead 145 is connected to ajunction 149 to which the lead 146 is connected. The lead 147 contains a normally closed coil relay switch SCR and a normally open reverse coil relay switch lRCR. The lead 147 is connected at a junction 150 to leads 151 and 152. Lead 151 contains a normally closed coil relay switch 8CRb. Lead 152, contains reverse coil relay RCR and two normally closed switches I53 and 185 contains a normally open switch 186. The lead 183 contains a momentary switch 187. A switch S7 can connect portions of the lead 183 to bypass the switch 187. A lead 184 connected to junction 185 and the lead 121 contains a high force relay coil HFRC.

A lead 188 is connected to the lead 123 and to

leads

189 and 190. The lead 189 contains a time delay coil relay TDCR and is connected to the lead 121.

Leads

191 and 192 are connected in parallel to each other and to a lead 193. Lead 191 contains a normally open switch 194 and a variable resistor 195. The lead 192 contains a normally closed switch 196. The lead 193 is connected to a selenium bridge rectifier 197. A lead 198 connected to the rectifier 197 contains a brake coil 199. A lead 200 connected to the rectifier 197 is connected to the lead 121.

A lead 201 is connected to the lead 123 and 121 and contains a normally open coil relay switch 9CR and the solenoid valve 70.

A lead 206, connected to'the lead ahead of the switch 122,'is connected to leads 207 and 208 at a junction 209.

Leads

207 and 208 are connected to each other at a junction 210. Lead 207 contains a momentary switch 211. Lead 208 contains a normally opencoil relay switch 4CR. A lead 212 connected to the junction 210 is connected to the conveyor controls and a lead 213 from the conveyor controls is connected to the lead 121.

When it is desired to form extrusions a billet 30 is loaded into the container 27 of the extrusion press 20 in conventional manner. The leading or forward end of the billet 30, which fits snugly in the bore 26, is in abutment with the rearface 23 of the die 22, and the frontor forward end of the ram 25 is in abutment with the rear end of the billet 30. When the main switch 122 is closed the various components can be supplied with electrical energy.

Let it be assumed that the gripper mechanism 38 is in the rest position shown-in FIG. 2, vane 113 actuates the switches 1S5 and 2S5 to energize coil relay CR5. Coil relay CR5 energizes normally closed switch 5CR to prevent energization of reverse coil relay RCR over'lead 147. The switch 154 is closed as long as it is manually depressed, and as switch 8CRb is closed, the reverse coil relay RCR is operated so long as the switch 154 is closed. The reverse coil relay RCR, when energized, closes the switch 161 to energize the reversecoil 156 of the motor 45, and closes contacts 178.

When the extruded end-42 has been formed by extruding a small amount of billet material through the opening 31 of the die 22 so that the extruded end 42 can be gripped by the gripper mechanism 38, the jogging switch 154 is manually closed to actuate the gripper mechanism 38 toward the die 22 into gripping position with the extrusion or extrusions. Cam surface 91 of bottom plate 91 earns the extrusions onto the plate 9I. The cam 41 actuates the roller 109 to trip the gripper mechanism 38 so that the

gripper elements

97 and 98 can grip the extrusion surfaces, for example extrusion surfaces E' and E" of extrusion E (FIG. 4). The switch S8 is so positioned that the switch S8 is actuated simultaneously with the gripping of the extrusion surfaces. Closing of the switch S8 energizes coil relay CR8 to simultaneously open switch 8CRb and close switch 8CRa. Closing of switch 8CRa causes energization of forward coil relay F RC to close the switch I60 to energize the forward coil 155 of the motor 45. Thereupon, the gripper mechanism 38, which is driven by the drive mechanism 44, exerts a forward pulling force on the extruded end or ends which form the leading marginal end or ends of the extrusion or extrusions. As the billet material is being extruded through the die 22, the gripper mechanism 38 exerts a sufficient pulling force on the extrusion or extrusions at their leading marginal end or ends to maintain the extrusion or extrusions substantially straight as they are being made. The force exerted on the gripper mechanism 38 is dependent upon the position of the contacterl74 along the resistance 167. The closer the contacter 174 is positioned to the junction 168 the more current is supplied to the clutch coil I80 of the clutch 46, and hence the less the slippage of the clutch 46. Hence, if desired, the contacter 174 can be manually positioned to cause greater current to energize the clutch 46 than is needed to keep the extrusion straight so as to cause the gripper mechanism 38 to cause slight stretching of the extrusions.

The gripper mechanism 38 continues to move toward the end of the runout table 32. Assuming that the billet material in the container 27 of the press 20 is substantially entirely extruded and only the butt remains, the forward movement of the ram 25 is stopped, this being a normal press function, and the forward movement of the gripper mechanism 38 stops because the force exerted by the extrusion or extrusions, the tail or tails of which are still in the opening or openings 3], respectively, of the die 22, is greater than the force exerted by the drive mechanism 44. The current to the clutch coil 180 of the clutch 46 remains constant but the clutch 46 continues to slip more and more as the gripper mechanism 38 comes to a standstill. The clutch 46 slips 100 percent when gripper mechanism 38 is at a standstill.

At the instant the butt is sheared off or separated from the tail or tails of the extrusion or extrusions, by shear 29, arm 29' connected to the piston rod of the piston-cylinder mechanism 28 actuates the switch S7. Momentary actuation of the switch S7 energizes the high force coil relay HFCR which closes switch 186 and holds switch 186 closed. High force coil relay HFCR simultaneously also closes switch 171 and opens switch 173. This causes current to pass through lead 169 to the clutch coil I80 rather than through the portion of the resistor 167 between the junction I69 and the contacter 174 and through the lead 172 to the clutch coil 180. The higher current being supplied to the clutch coil I80 causes greateractuating force to be transmitted to the speed reducer 49 and the cable 51. This greater force is transmitted to the gripper mechanism 38 and when the force increases to a value sufficient to overcome the holding force exerted by the extrusions, movement of the gripper mechanism 38 is started. The speed of gripper mechanism 38 increases gradually and without jerking action which causes undue stretching of the extrusion. After the trailing marginal ends of the completed extrusions have been pulled out of the die openings 31, the gripper mechanism 38 speeds the completed extrusions, which it is pulling and causing them to slide on the upper surface 39 of the runout table 32, toward the end of the runout table 32.

Upon engagement of the cam follower with the cam 43, the cam follower 95 is quickly swung to the phantom line position indicated in FIG. 11. This quick action is due to the angle at which the cam follower 95 strikes the cam 43. Flange 112 slides in contact with the bottom of the guide rail 40 to prevent the gripper mechanism from being lifted off the top surface 39 of the table32 andv the top of guide rail 40 upon forcible contact of thecam follower 95 with the cam 43; The

gripper elements

97 and 98 move from the brokenlin'e position to the phantom line position, shown in FIG. 11. As soon as the

gripper elements

97 and 98 loose gripping engagement with the extrusion surfaces which they are gripping, the gripper elements are considered to be released. Immediately after release of the gripper elements 97, the vane 113 actuates switch S9. Switch S9 energizes coil relay CR9 which closes and holds switch 9CR closed. Switch 9CR remains closed so long as switch S9 is actuated by the vane 113. The switch 9CR when closed energizes the solenoid valve 70 which causes a condition of vacuum to exist in the conduit 72 instead of the conduit 71. This drives the piston rod 65 of the piston-cylinder mechanism 63 downwardly, specifically in a substantially vertical direction, until the jaw 66 clamps the extrusions against the stationary block or jaw 67. The entire piston-cylinder mechanism 63 yields, as depicted by the phantom line position in FIG. 12. This enables clamping action at the leading marginal ends of the extrusions to yield.

Continued movement of the gripper mechanism 38 will cause vane 113 to actuate switch S4 to energize coil relay CR4.

When the vane 113 actuates either one or both of switches 1S3 and 2S3, coil relay CR3 is energized to open contact 3CR, thus deenergizing forward coil relay FCR to open switch to in turn deenergize forward coil 155. Deenergization of forward coil relay FCR opens switch lFCR and closes one of the switches 188' to energize the brake 47, and opens the switches 178.

When switch S4 is closed, coil relay CR4 closes switch 4CR to cause energization of the conveyor controls. The conveyor controls forming part of the transverse conveyor 73 which includes the drive mechanism 80 with its reversible electric motor and the piston-cylinder mechanism 76. The pistoncylinder mechanism 76 operates first to rotate the cam 75 of each lifting and transverse conveying assembly 73', thus lifting the elements 77 out of the gaps 78 and above the upper surface 39 of the runout table 32. The vane 77', secured to the end of one of the elements 77 energizes switch S1 because this element 77 (as do the remaining elements 77) pivots about shaft 79. Actuation of switch S1 energizes the coil relay CR1 which opensswitch lCR preventing operation of the forward coil relay FCR or the reverse coil relay RCR and thus preventing closing of either of the switches 160 and 161. As the elements 77 move transversely away from the runout table 32, the switch S2 is closed thus energizing coil relay CR2. Closing of the switch S2 enables and in particular causes the reverse coil relay RCR to be energized to close the switch lRCR and to close the switch 161 to energize reverse coil 156 of the motor 45 to move the gripper mechanism 38 rearwardly along the runout table 32. While the gripper mechanism 38 is moving rearwardly the piston-cylinder mechanism 76 is actuated to pivot the elements 77 counterclockwise as viewed in FIG. 9. Immediately thereafter the drive mechanism 80 operates the pinions 8] to drive the elements 77 transversely toward the runout table 32 horizontally into the respective gaps 78.

The fact that either one or both of switches I53 and 283 are closed by the vane 113 when the gripper mechanism 38 is at a standstill at the position indicated by phantom lines in FIG. 2

does not prevent energization of the reverse coil relay RCR because the switch 3CR is in parallel with the reverse coil relay RCR.

When the vane 113 actuates the switch S4 on return movement of the gripper mechanism 38, switch S4 is closed but coil relay CR4 is not energized because switches lFCR, 8CRa, and the momentary switch 144 are all open. It is apparent that because the conveyor controls cannot be energized by closing the switch S4, the gripper mechanism 38 cannot collide with the lifting and conveying elements 77, which during the beginning part of their movements, are situated above the upper surface 39 of runout table 32.

Closing of switch S9 by the vane 113 does not energize coil relay CR9 because switches IFCR, 8CRa, and momentary switch 144 are open. Thus, the solenoid valve 70 is not energized and the arresting means 62 is not operated.

The high force coil relay HFCR remains energized on the return or reverse movement of the gripper mechanism 38 because contact 186 is still being held closed by the high force coil relay HFCR. When the vane 113 actuates switch 86 the coil relay CR6 is energized, which in turn opens switch 6CR. Thus, high force coil relay HFCR is deenergized and switch 173 is closed and switches 171 and 186 are opened. Low current passes through lead 172 to the clutch coil 180 of clutch 46, so that speed of the gripper mechanism 38 is reduced. The switch S6 is relatively close to the rest position of the gripper mechanism so that the gripper mechanism travels at high speed for nearly the full length of its travel rearwardly. The reanvard movement of the gripper mechanism 38 continues until the vane 113 closes 185 or 285, or both. Closure of either of both of switches ISS and 255 energize coil relay CR which in turn opens contact SCR to deenergize reverse coil relay RCR to open the switch 161. Reverse coil relay RCR closes one of the switches 188 when reverse coil relay RCR is deenergized, thus enabling current to pass to

leads

189 and 190. Current passes through lead 192, lead 193, and lead 198 to energize the brake coil 199 of brake 47 with high current because lead 196 contains no resistor. The current through lead 189 energizes time delay coil relay TDCR which alternately operates

switches

194 and 196 after a time delay. When the time delay coil relay TDCR has opened switch 196 and closed switch 194, current can no longer pass through lead 196, but rather passes through lead 194 and its resistance 195. Energization of the brake 47 applies a braking force to the speed reducer 49 and the cable 51 to stop the gripper mechanism 38.

The

switches

183, 253, S4, 185, 285, S6, S8 and S9 are preferably all of the vane or proximity type and are mounted for longitudinal movement by and lengthwise of the frame 36 of the runout table 32. Switches S1 and S2 are also of the vane or proximity type and are adjustably mounted relative to operating vane 77.

Cooling means C'of any suitable type can be disposed a short distance above the upper surface 39 of the runout table 32 and extend lengthwise thereof, for example and distance of about 14 inches or less depending upon the height of the gripper mechanism 38. The cooling means C can be in the form of ducts as shown or can be in the form of separate fans. In either form, the cooling means C can include means for directing water spray onto the extrusions on the runout table 32.

Although electrical circuitry has been illustrated, it is apparent that pneumatic or hydraulic circuitry could be used instead.

The above-described embodiment being exemplary only it is to be understoodthat modifications and variations can be made without departing from the spirit and scope of the invention defined in the following claims.

We claim:

1. In an apparatus for pulling and handling extrusions, for use with an extrusion press: a runout table, means movable along said runout table for gripping the leading marginal end of an extrusion, means for driving said gripping means to exert a force on said gripping means to maintain the extrusion substantially straight as it is being formed, means for releasing said gripping means from gripping engagement with the leading marginal end, means for transferring the extrusion off said runout table, means for sensing when said transferring means has cleared said runout table, and means responsive to said sensing means for enabling said driving means to return said gripping means along said runout table.

2. In an apparatus for pulling and handling extrusions, for use with an extrusion press: a runout table, a gripper mechanism movable along said runout table, means for driving said gripper mechanism, means for actuating said gripper mechanism to release the gripped extrusion, means disposed along said runout table for arresting the forward movement of the released extrusion, means disposedalong said runout table for conveying extrusions off said runout table, and means effective when said arresting means has been actuated to actuate said conveying means.

3. In an apparatus for pulling extrusions, for use with an extrusion press: a runout table, means movable along said runout table for gripping the forward marginal end of an extrusion, means for driving said gripping means, means for operating said gripping means to release the leading marginal end of the extrusion when the extrusion is complete, and means separate and distinct from said driving means and said gripping means and operable when said gripping means has been released to arrest the forward movement of the completed extrusion.

4. In an apparatus for pulling extrusion, for use with an extrusion press: a runout table having a relatively low coefficient of friction, means movable along said runout table for exerting a pulling force on the leading marginal end of an extrusion to maintain the extrusion substantially straight as it is being pulled over and supported by said runout table, and means separate and distinct from said pulling means for arresting the movement of the completed extrusion on said runout table.

5. In an apparatus for pulling extrusions, for use with an extrusion press: a runout table, means movable along said runout table for exerting a pulling force on the leading marginal end of an extrusion to maintain the extrusion substantially straight as it is being pulled over and supported by said runout table, means for arresting the movement of the completed extrusion on said runout table, and means for enabling said arresting means to yield upon engagement with the extrusion to prevent the extrusion from buckling.

6. In an apparatus for pulling extrusions, for use with an extrusion press: a gripper mechanism movable in forward and rearward directions, means ,for driving said gripper mechanism, means for operating said driving means including means for actuating said driving means to drive said gripper mechanism forwardly and means for actuating said driving means to drive said gripper mechanism rearwardly, said operating means including an electric clutch and a brake, means for selectively energizing said electric clutch with low and high current to selectively cause low and high forces, respectively, to be exerted on said gripper mechanism, means for preventing said clutch energizing means from energizing said clutch with high current until the but has been sheared from the extrusion, means for actuating said gripper mechanism to release the completed extrusion, means for interrupting the forward movement of the extrusion released by said gripper mechanism, means for deactuating said clutch and actuating said brake after said gripper mechanism has proceeded beyond the end of the extrusion, means for conveying the extrusion out of the path of said gripper mechanism, means for actuating said conveying means when said gripper mechanism has cleared the end of the extrusion, and means operable upon said conveying means having cleared the path of said gripper mechanism for causing actuation of said rearward drive actuating means.

7. in an apparatus for pulling extrusions, for use with an extrusion press: a gripper mechanism, means for driving said gripping mechanism forwardly away from a die of an extrusion press and rearwardly toward the die, said gripper mechanism having a frame, a shaft mounted in said frame and extending transversely to the direction of movement of the gripper mechanism, a plurality of gripper elements pivotally mounted on said shaft, said gripper elements having arched lower surfaces, said lower surfaces being roughened, means secured to said shaft and engageable with said gripper elements for moving said gripper elements out of gripping position when said shaft is rotated, means for latching said shaft and said gripper elements out of said gripping position, a cam follower secured to said shaft, a first cam along the path of travel of said gripper mechanism for tripping said latching means to pivot the gripper elements into gripping position, and a second cam engageable with said cam follower for operating said moving means into latching position to be latched by said latching means.

8. In an apparatus for pulling extrusions, for use with an extrusion press: a runouttable at least the upper surface of which is composed of a material having a relatively low coefficient of friction and having the ability to withstand elevated temperatures, a gripper mechanism slidable on said runout table and being adapted to grip a plurality of extrusion surfaces, said gripper mechanism including a plurality of individual gripper elements, and means mounting said individual gripper elements for independent movement into gripping engagement with the extrusion surfaces.

9. In an apparatus for pulling extrusions, for use with an extrusion press: a runout table at least the upper surface of which is composed of a material having a relatively low coefficient of friction and having the ability to withstand elevated temperatures, an extrusion gripper mechanism having a substantially flat lower surface slidable on the upper surface of said runout table, and means for driving said gripper mechanism to slide forwardly and rearwardly on the upper surface of said runout table.

10. Method of making an extrusion from a billet composed of extrudable material, comprising the steps of: extruding a small amount of billet material through an opening of an extrusion die to form an extruded end, jogging a gripper mechanism from a rest position situated slightly beyond the extruded end into gripping position with the extruded end, gripping the extruded end with the gripper mechanism, and exerting sufficient force on the gripper mechanism as the material is being extruded to maintain the extrusion substantially straight.

11. Method of handling an extrusion made from a billet composed of extrudable material, comprising the steps of: extruding the billet material through an extrusion die, exerting a pulling force on the leading marginal end of the extrusion to maintain the extrusion substantially straight as the extrusion is being made, increasing the pulling force to draw the marginal trailing end of the completed extrusion out of the die, and arresting the forward movement of the extrusion.

12. Method of handling extrusions made from a billet composed of extrudable material, comprising the steps of: extruding billet material through an extrusion die and passing the first extrusion onto a runout table as it is being made, pulling the completed first extrusion toward the end of the runout table opposite the extrusion die, increasing the pulling force to draw the marginal trailing end of the completed extrusion out of the die, arresting the movement of the first extrusion so that the leading end of the first extrusion is pulled to a predetermined position along the runout table, conveying the first extrusion off said runout table transversely, subsequently extruding additional billet material through the extrusion die and passing the second extrusion onto the runout table as it is being made, pulling the completed second extrusion toward the end of the runout table opposite the extrusion die, and arresting the movement of the second extrusion so that the leading end of the second extrusion is pulled to approximately the predetermined position along the runout table so that the leading ends of the first and second extrusions are approximately transversely aligned, and conveying the second extrusion transversely.