GB2328670A - A billet transfer apparatus - Google Patents

Abstract

A billet transfer apparatus for use with a metal extrusion press comprises a base structure (1) supporting a carriage (2) movable (1) between a first position and a second position. A jaw arrangement (10) is mounted on the carriage (1) and is adapted for carrying a sheared billet (11). Means (12,13, 14) are provided for rotating the jaw arrangement (10) relative to the base structure (1) in order to rotate a carried billet (11) through 180‹ about a vertical axis normal to its longitudinal axis. The jaw arrangement (10) can also be moved vertically relative to the base structure (10) between first and second levels. Means (7,8) are also provided for moving the carriage relative to the base structure (1) between said first and second positions. Thus, during one cycle of operation, the jaw arrangement (10) can be loaded with a sheared billet (11) from a shear cutter (S), moved to a said second level, and transported by movement of the carriage (2) into said second position wherein a carried billet (11) can be off-loaded into a container (C) of an adjacent extrusion press (P). Preferably a lubricator (16), a pusher (17) and a further clamp (18, Fig 1) for undersize billets are also provided.

Description

A BILLET TRANSFER APPARATUS The present invention relates to a billet transfer apparatus for use with a metal extrusion press and associated equipment.

In a conventional metal extrusion operation, a metal billet or log is heated in a furnace and an appropriately sized piece is cut or sheared therefrom by a shear cutter.

This piece, hereinafter referred to as a sheared billet, is then transported to a lubrication station where it is coated with graphite prior to being loaded into a container of an extrusion press for compression and extrusion by a ram.

Typically, the sheared billet is transported between the various pieces of apparatus making up the extrusion press assembly on roller conveyors or similar arrangements. However, these conveyors have the disadvantage that the sheared billet rolls and may loose its position making it difficult to locate in the container, especially when transporting a two-piece billet. In addition it will be appreciated that in order to avoid waste, it is advantageous to use the whole of a log but an end piece may be left after several sheared billets have been removed which is too small to use. The time spent in retaining and combining two such end pieces to form a single billet for loading into the container can significantly increase the down time of a press and therefore reduce its efficiency.

Conventional apparatus used for the external heating of a billet by burners usually sets up a temperature profile along the billet with the temperature lower at the end nearer to the furnace door. A similar profile will therefore exist in the sheared billet. However, it is desirable when loading the sheared billet into the container of the press for the hotter end of a billet to be loaded therein first. This is because as the billet is subjected to compression by the ram, the hotter end expands faster to fill the cylindrical container diametrically, which expels air from the container around the die and thereby reduces the likelihood of blistering occurring on the surface of the resultant extrusion. It also reduces the likelihood of metal creep around the back of the ram. The efficiency of the extrusion operation is also increased as hotter end of the billet is extruded first, leaving time for the colder end to heat up to the desired temperature prior its extrusion. In most conventional apparatus, however, no provision is made for a turning operation to be carried out on sheared billets that have been heated by burners because it must be done manually, which significantly increases the down time of the extrusion press.

The object of the present invention is to provide a billet transfer apparatus which will overcome or substantially mitigate the aforementioned disadvantages of conventional apparatus involving the rolling and turning of sheared billets. The apparatus has also been designed with a view to keeping the distance travelled by a sheared billet between the shear cutter and the container of an extrusion press to a minimum and with a view to sideways space limitations which may exist between the shear cutter and the press.

It is also an object of the present invention to provide a billet transfer apparatus which can be readily adapted to cope efficiently with the retention and combination of the end pieces of billets as part of twopiece billets.

According to the present invention there is provided a billet transfer apparatus for use with a metal extrusion press comprising a base structure supporting a carriage which can traverse over the base structure between a first position and a second position; a jaw arrangement mounted on the carriage and adapted for carrying a sheared billet; means for rotating the jaw arrangement relative to the base structure in order to rotate a carried billet through 180 about an axis normal to its longitudinal axis; means for moving the jaw arrangement vertically relative to the base structure between a first level and a second level; and means for moving the carriage relative to the base structure between said first and second positions, whereby during one cycle of operation the jaw arrangement can be located at the first level in said first position of the carriage wherein it can be loaded with a sheared billet, moved to said second level, and transported by movement of the carriage into said second position wherein a carried billet can be off-loaded into a container of an adjacent extrusion press.

Preferably, the jaw arrangement comprises a lower support jaw and an upper jaw which can pivot relative to the lower jaw between an upper open position and a lower closed position wherein it will arrest movement of a carried billet relative to the lower jaw.

Preferably also, the lower support jaw can pivot between a first position located at said first level and a second position located at said second level, at both of said levels it being capable of supporting a sheared billet.

Preferably also, at least the lower support jaw comprises first and second jaw members which can slide relative to one another whereby the length of the lower jaw can be increased or decreased to accommodate sheared billets of different length. Advantageously, the upper jaw also comprises first and second jaw members which can slide relative to one another whereby the length of the upper jaw can be increased or decreased to arrest sheared billets of different length.

Preferably also, the jaw arrangement comprises an arm to which the upper and lower jaws are independently pivotally mounted, the arm being connected to the carriage via a shaft around which it can be rotated about a vertical axis relative to both the carriage and the base structure whereby the carried billet can be rotated through the aforesaid 1800.

Preferably also, the carriage comprises an upper part and a lower part, the upper part being moveable transversely across the lower part relative to movement of the carriage over the base structure, and means for moving the upper part relative to the lower part.

Preferably also, the base structure comprises a first pair of rails over which the carriage can travel and the lower part of the carriage comprises a second pair of rails perpendicular to said first pair of rails over which the upper part of the carriage can travel relative to the lower part.

Advantageously, the apparatus comprises a clamp arrangement which can be used to off-load short sheared billets from the jaw arrangement for subsequent combination with another such billet.

Preferably also, the apparatus comprises a frame which supports the clamp arrangement above the carriage via ram means whereby the clamp arrangement can be raised and lowered relative to the frame.

Preferably also, the frame supports the clamp arrangement at a position wherein before rotation of the jaw arrangement through the aforesaid 1800 relative to the base structure, the lower jaw of the jaw arrangement can be located vertically below the clamp arrangement which can be lowered by the ram means to retrieve a billet being supported by the lower jaw.

Preferably also, the frame supports a lubricating means for the external lubrication of a carried billet.

Preferably also, the means for moving the carriage relative to the base structure between said first and second positions are capable of halting movement of the carriage at a third position wherein the jaw arrangement is located adjacent the lubricating means whereby a sheared billet being carried by the jaw arrangement can be lubricated.

Preferably also, the lubricating means is mounted to the frame via means enabling the lubricating means to be moved inwardly of the frame into contact with one end of a sheared billet being carried by the jaw arrangement when the carriage is halted at said third position.

Preferably also, movement of the lubricating means when in contact with said one end of a sheared billet being carried by the jaw arrangement when the carriage is halted at said third position causes said first and second jaw members to slide relative to one another whereby the length of the lower jaw is decreased until it equals that of the carried billet.

Preferably also, the frame supports a pusher means which can act on the jaw arrangement whereby said first and second jaw members can be slid relative to one another to increase the length of the lower jaw to its maximum extent.

Preferably also the action of the pusher means on the jaw arrangement acts on both the upper and the lower jaw to increase the length of both to their maximum extent.

The present invention will now be described by way of example with reference to the accompanying drawings, in which:- Figs. 1, 2 and 3 are schematic side, end and plan views respectively of a billet transfer apparatus according to the present invention, Figs. 1 and 2 showing the apparatus with a jaw arrangement thereof in a fully extended position; Fig. 4 is a schematic side view of the apparatus similar to that shown in Fig. 1 but with the jaw arrangement shown in a rotated and retracted position; Figs. 5 and 6 are side and plan views respectively and to a larger scale of the jaw arrangement forming part of the apparatus shown in Figs. 1 to 4; Figs 7 and 8 are end and plan views respectively and to a larger scale of a frame arrangement mounting lubrication apparatus which also forms part of the apparatus shown in Figs 1 to 4; and Fig. 9 is a side view of a clamp arrangement, again to a larger scales which also forms part of the apparatus shown in Figs 1 to 4.

As shown in Figs 1 to 4, a billet transfer apparatus for transporting a sheared billet from a shear cutter to an extrusion press comprises a base structure 1 supporting a carriage 2 which can move back and forth relative to the base structure on rails 3. The carriage 2 has upper and lower parts 4 and 5 respectively and the upper part 4 can slide transversely across the base part 5 on rails 6 that are perpendicular to the rails 3. Two hydraulic rams 7 and 8 are provided in the base structure 1 by means of which the movement of the carriage 2 relative to the base structure 1 can be controlled. Similarly, a hydraulic ram 9 connected between the lower and upper parts 4, 5 of the carriage 2 is provided to move the upper part 4 of the carriage 2 transversely relative to the lower part 5.

Mounted on the upper part 4 of the carriage 2 is a jaw arrangement 10, as shown in Figs 5 and 6, for carrying a sheared billet 11 between the shear cutter and the extrusion press. The jaw arrangement 10 is capable of being rotated through 180 relative to the carriage 2 about a vertical shaft 12 provided with bearings 13 by means of a chain drive arrangement 14.

Mounted at one end of the base structure 1 is an overhead frame 15 under which the carriage 2 and thereby the jaw arrangement 10 can be moved relative to the base structure 1. The frame 15 mounts a lubrication apparatus 16 and a pusher arrangement 17 which interact with the jaw arrangement 10 during use of the apparatus as will be described. The frame 15 also mounts an insulated clamp arrangement 18 via a beam 19 which projects normally from a cross beam 20 of the frame 15. This clamp arrangement 18 and its associated controls comprises an optimizer which can be used to retain short sheared billets 21 for later combination with another prior to use.

Various components of the apparatus will now be described in more detail with particular reference to Figs. 5 to 9.

The jaw arrangement 10 shown in Figs. 5 and 6 comprises a lower support jaw 22 of vee-shaped transverse cross-section and an upper arrester jaw 23 both of which are independently pivotal about a pivot pin 24 by means of hydraulic cylinders 25 and 26 respectively. Extension of the cylinders 25 and 26 lowers and raises the jaws 22 and 23 respectively, opening them, whereas retraction of the cylinders 25 and 26 closes the jaws 22 and 23. The lower support jaw 22 is capable of rotation through approximately 30 between a lower position wherein it can receive delivery of the sheared billet 11 from the shear cutter and an upper position, as shown in Fig. 5, wherein it has raised the level of the longitudinal axis of the billet 11 to the same level as the longitudinal axis of the container of the extrusion press.

The pivot pin 24 and the cylinders 25 and 26 are located in a swivel arm 27 which can be rotated through 1800 about the shaft 12 by means of the chain drive arrangement 14, as previously mentioned. The chain drive arrangement 14, a chain tensioning mechanism 28 therefor, and the bearings 13 for the shaft 12 are located in a housing 29 which is attached to the upper part 4 of the carriage 2. The drive means for the chain of the arrangement 14 are located in the upper part 4 of the carriage 2 and are not shown in the drawings.

Each of the jaws 22 and 23 is extensible horizontally by means of slides 30 and 31 respectively. The lower slide 30 is located in the base of the jaw 22 and is also of vee-shaped transverse cross-section. It is provided with runners 32 at each side which travel in guide channels 33 defined by the jaw 22 whereby when fully extended the horizontal length of the lower jaw can be nearly doubled.

Similarly, the upper slide 31 comprises a block which can slide within a channel 34 formed in the upper jaw 23 whereby the length of the arrester jaw 23 can be similarly extended to match that of the lower jaw 22. Extension and retraction of the jaws 22 and 23 is achieved simply by pushing the slides 30 and 31 relative to the fixed portions of the jaws 22, 23.

Turning now to the frame 15 and associated lubrication apparatus 16 and pusher arrangement 17, it can be seen in Fig. 7 that the lubrication apparatus 16 comprises a conventional sooter head 35 which is attached to a horizontal slide 36 mounted via a bracket 37 to one of the uprights 38 of the frame 15. The slide 36 can slide through the bracket 37 to support the head 35, which is acted on by an hydraulic cylinder 39 whereby it can be pushed inwardly of the frame 15 and retracted as required.

The height of the slide 36 on the upright 38 is dependent on the height of a container of an associated extrusion press and is arranged to be at the same level as that of the longitudinal axis of the container.

Opposite the lubrication apparatus 16 on the other upright 40 of the frame 15 is located the pusher arrangement 17. This arrangement 17 is similar to the arrangement 16 in that it comprises a pusher head 41 which is attached to a horizontal slide 42 mounted via a bracket 43 to the upright 40. As with the sooter head 35, the slide 42 can slide through the bracket 43 to support the pusher head 41, which is acted on by an hydraulic cylinder 44 whereby it can be pushed inwardly of the frame 15 and retracted as required.

Mounted immediately below the pusher head 41 is a spring loaded pusher head pin 45 comprising a switch that is linked to control apparatus controlling the operation of the hydraulic cylinder 39 which extends and retracts the sooter head 36.

As previously mentioned, the frame 15 also mounts the clamp arrangement 18 via a projecting beam 19. This arrangement 18 comprises a pair of insulated jaws 46 which are capable of clamping around and lifting the short sheared billet 21 as shown in Fig. 9. The jaws 46 are both pivotally mounted to a pin 47 located within a cradle 48 and they are not independently operable. Automatic opening and closing of the jaws 46 is achieved by operation of a pneumatic cylinder 49 which is attached to one of the jaws 46 and to the cradle 48. The cradle 48 itself is attached to the beam 19 via a pneumatic cylinder 50 whereby the jaws 46 can be lowered or raised with respect to the beam 19 and thereby the underlying carriage 2. Guide bars 51 which slide through the beam 19 are also used to support and guide the movement of the jaws 46 as they are raised and lowered by the cylinder 50.

The cycle of operation of the billet transfer apparatus will now be described. Operation of the various phases within the cycle are made to occur automatically by the use of micro-switches and similar within the apparatus. However, a manual override capability is also provided.

In use, the billet transfer apparatus is located between a shear cutter S and an extrusion press P as shown in Fig. 3. The apparatus is positioned adjacent a moving cutter tool T of the shear cutter S, which shears off appropriately sized billets from a larger main billet or log as required for a particular extrusion operation. The transfer apparatus turns the sheared billet through 1800, lubricates it and then locates it in a position wherein it can be loaded directly into a container C of the extrusion press P by a ram M of the press P.

In a complete cycle, the carriage 2 is first located in its retracted position relative to the base structure 1 with the jaw arrangement 10 rotated into a position overlying the carriage 2 and with the jaws 22 and 23 in their fully extended positions, as shown in Fig. 4. A stop (not shown) is fitted to the shear cutter S against which the lower support jaw 22 is lowered. In this position, the apparatus is set up so that the lower support jaw 22 is directly adjacent the outlet of the adjacent shear cutter S at a height wherein the extended lower support jaw 22 can receive the end E of a billet as it is pushed out of the shear cutter S by a ram R. As the shear cutter S operates to shear the egressed portion of the billet it moves in a direction parallel with the rails 3 of the transfer apparatus and a stop on the cutter bears against the carriage 2 and forces it to move therewith along the rails 3 relative to the base structure 1. At the end of the billet shearing operation, the shear cutter S ceases movement and thereby ceases moving the carriage 2 along the rails 3. At this point in the cycle the sheared billet 11 is fully located on the extended slide 30 of the lower support jaw 22 and severed from the log which is retained in the shear cutter S.

The lower support jaw 22 is now rotated upwards by means of the hydraulic cylinder 25, raising the sheared billet 11 to a position wherein the longitudinal axis of the billet 11 is at the same horizontal level as the longitudinal axis of the container of the adjacent extrusion press. The upper jaw 23 is then rotated downwardly by the hydraulic cylinder 26 almost into contact with the billet 11 in order to arrest any movement of the billet 11 out of the jaw arrangement 10 during its subsequent transportation.

The hydraulic ram 5 then moves the carriage 2 along the rails 3 until the jaw arrangement 10 is located in a position directly below the clamp arrangement 18. If the billet 11 being carried by the jaw arrangement is a piece for "optimization", that is the end portion of a log rather than one of a predetermined length for immediate extrusion, the clamp arrangement 18 can be operated to retrieve this billet 21 from the jaw arrangement 10 and retain it for later combination with another end piece from subsequent log. It will be appreciated that in these circumstances, the upper jaw 23 is raised and the jaws 46 are opened by the cylinders 26 and 49 respectively. The jaws 46 are then lowered by the cylinder 50 and clamped around the billet 21 before being raised along with the clamped billet 21. This billet 21 is then retained by the clamp arrangement 18 until the jaw arrangement 10 is again to receive a short billet for combination with the retained billet, as is further described below. If the clamp arrangement 18 is brought into operation to retain the billet 21, then after removal of the billet 21 from the jaw arrangement 10, the carriage 2 can be retracted back to its original position adjacent the outlet from the shear cutter as described above and made ready to receive the next sheared billet therefrom. Otherwise, the operation cycle of the apparatus continues as follows.

If the clamp arrangement 18 is not to be brought into use at this point in the operation cycle, the upper part 4 of the carriage 2 is moved transversely with respect to the lower part 5 along the rails 6 by the hydraulic ram 9.

The jaw arrangement 10 is then rotated through 1800 relative to the carriage 2 by means of the chain drive arrangement 14. The billet 11 has now been rotated relative to the extrusion press so that its hotter end, namely that which regressed last from the shear cutter is in a position to be loaded first into the container of the press.

The relative dimensions of the apparatus are arranged such that after rotation of the jaw arrangement 10, the billet 11 is located in line with the sooter head 35 as shown in Fig. 2. The sooter head 35 is now extended inwardly of the frame 15 by the cylinder 39 into contact with the adjacent end of the billet 11. The sooter head 35 continues to bear against the billet 11 under the action of the cylinder 39 so that the slides 30 and 31 of the jaws 22 and 23 are forced to retract and the billet 11 is likewise moved along the lower jaw 22 towards the pusher head pin 45. When the billet 11 contacts the pin 45, this triggers a signal stopping further extension of the cylinder 39 and initiating a sooting operation wherein the surface of the billet 11 is coated with graphite that acts as a lubricant to assist the sliding of the billet into the container of the press. Typically the sooting operation comprises the burning of acetylene around the billet 11 to produce the graphite.

After the sooting operation has been completed, the sooter head 35 is retracted by the cylinder 39. Thereafter when required by the press P, the second hydraulic ram 8 in the base structure 1 operates to move the carriage 2 further forward into the position shown in Figs 1 and 2 wherein the longitudinal axis of the billet 11 is in-line with the longitudinal axis of the container C of the press P and is located between the container C and the main ram M of the press. The upper arrester jaw 23 is then raised and the ram Mof the press P can be brought into operation to push the billet 11 off the lower jaw 22 and load it directly into the container C.

After loading of the billet 11, the lower support jaw 22 is lowered by the cylinder 25 so that the jaws 22 and 23 are fully open as they were at the start of the operation cycle. The ram 8 then retracts the carriage 2, the open jaws 22 and 23 clearing the ram X, until the jaws 22 and 23 are again in-line with the frame 15 and in particular the pusher arrangement 17. The jaws 22 and 23 are then closed by their respective cylinders 25 and 26.

The cylinder 44 of the pusher arrangement 17 is then operated to bring the pusher head 41 into contact with the jaws 22 and 33. The pusher head 41 is constructed so that with the jaws 22 and 23 in their fully closed position, it only bears against the slides 30 and 31 which are thereby forced to move, fully extending the jaws 22 and 23. After achieving full extension of the jaws 22 and 23, the cylinder 44 is retracted so retracting the pusher head 41.

Thereafter the upper arrester jaw 23 is raised and the jaw arrangement 10 is rotated back through 1800 relative to the carriage 2 by means of the chain drive arrangement 14.

The upper part 4 of the carriage 2 is moved transversely back over the rails 6 by retraction of the ram 9 so that jaw arrangement 10 is once more beneath the clamp arrangement 18. If clamp arrangement 18 is currently retaining an "optimized" billet 21 and the next cycle of operation of the shear cutter will also produce a short piece of billet for optimization, then at this point in the cycle, the clamp arrangement 18 can be operated to locate the retained billet 21 back on the lower jaw 22.

Otherwise, at this point, the hydraulic ram 7 is operated to retract the carriage 2 back to its original position adjacent the outlet from the shear cutter. The lower jaw 22 is then rotated downwardly into contact with the shear cutter stop.

A single cycle of the apparatus has now been completed and can be repeated as desired. Typically an aluminium extrusion press extrudes in the region of 35 billets per hour and the billet transfer apparatus of the present invention can be set up to work at a speed synchronous with the requirements of such a press. The apparatus is such that it can be readily adapted to work between any conventional billet heating/cutting apparatus and extrusion press combination.

It will be appreciated that during the operation of the transfer apparatus, a billet is always supported during its travel between the shear cutter and the press and is never permitted to roll. In addition, the jaw arrangement enables a sheared billet to be turned and lubricated swiftly and efficiently. The clamp arrangement 18 is also set up to operate as an integral part of the operating cycle of the apparatus when required.

Use of the apparatus can also have an advantageous effect on the manner in which the extrusion press itself is operated. For example, when sooter head 35 is extended into contact with the billet 11 and the jaws 22 and 23 are retracted, the length of the billet 11 is effectively being measured as extension of the sooter head 35 is stopped when the billet 11 pushes against the pusher head pin 45. This information can be transmitted to the extrusion press so that the ram of the press is retracted to a degree sufficient only to load that particular billet 11 into the container at the appropriate part of the operation cycle. This increases the efficiency of the press.

The apparatus can also be modified to provide a cold billet eject facility at any point in the cycle except for the last movement into the press. Such an arrangement can be set up to operate if the carriage 2 is moved transversely away from the shear cutter and away from the press, the jaw arrangement 10 not being rotated towards the press in order to eject the billet onto a tray provided for the purpose by the lowering of the lower support jaw 22.

Claims (18)

1. A billet transfer apparatus for use with a metal extrusion press comprising a base structure supporting a carriage which can traverse over the base structure between a first position and a second position; a jaw arrangement mounted on the carriage and adapted for carrying a sheared billet; means for rotating the jaw arrangement relative to the base structure in order to rotate a carried billet through 1800 about an axis normal to its longitudinal axis; means for moving the jaw arrangement vertically relative to the base structure between a first level and a second level; and means for moving the carriage relative to the base structure between said first and second positions, whereby during one cycle of operation the jaw arrangement can be located at the first level in said first position of the carriage wherein it can be loaded with a sheared billet, moved to said second level, and transported by movement of the carriage into said second position wherein a carried billet can be off-loaded into a container of an adjacent extrusion press.

2. An apparatus as claimed in Claim 1, wherein the jaw arrangement comprises a lower support jaw and an upper jaw which can pivot relative to the lower jaw between an upper open position and a lower closed position wherein it will arrest movement of a carried billet relative to the lower jaw.

3. An apparatus as claimed in Claim 2, wherein the lower support jaw can pivot between a first position located at said first level and a second position located at said second level, at both of said levels it being capable of supporting a sheared billet.

4. An apparatus as claimed in Claim 2 or Claim 3.

wherein the lower support jaw comprises first and second jaw members which can slide relative to one another whereby the length of the lower jaw can be increased or decreased to accommodate sheared billets of different length.

5. An apparatus as claimed in any one of Claims 1 to 4, wherein the upper jaw comprises first and second jaw members which can slide relative to one another whereby the length of the upper jaw can be increased or decreased to arrest sheared billets of different length.

6. An apparatus as claimed in any one of Claims 1 to 5, wherein the jaw arrangement comprises an arm to which the upper and lower jaws are independently pivotally mounted, the arm being connected to the carriage via a shaft around which it can be rotated about a vertical axis relative to both the carriage and the base structure whereby the carried billet can be rotated through the aforesaid 1800.

7. An apparatus as claimed in any one of Claims 1 to 6, wherein the carriage comprises an upper part and a lower part, the upper part being moveable transversely across the lower part relative to movement of the carriage over the base structure, and means for moving the upper part relative to the lower part.

8. An apparatus as claimed in any one of Claims 1 to 7, wherein the base structure comprises a first pair of rails over which the carriage can travel and the lower part of the carriage comprises a second pair of rails perpendicular to said first pair of rails over which the upper part of the carriage can travel relative to the lower part.

9. An apparatus as claimed in any one of Claims 1 to 8, wherein the apparatus comprises a clamp arrangement which can be used to off-load short sheared billets from the jaw arrangement for subsequent combination with another such billet.

10. An apparatus as claimed in any one of Claims 1 to 9, wherein the apparatus comprises a frame which supports the clamp arrangement above the carriage via ram means whereby the clamp arrangement can be raised and lowered relative to the frame.

11. An apparatus as claimed in Claim 10, wherein the frame supports the clamp arrangement at a position wherein before rotation of the jaw arrangement through the aforesaid 1800 relative to the base structure, the lower jaw of the jaw arrangement can be located vertically below the clamp arrangement which can be lowered by the ram means to retrieve a billet being supported by the lower jaw.

12. An apparatus as claimed in Claim 10 or 11, wherein the frame supports a lubricating means for the external lubrication of a carried billet.

13. An apparatus as claimed in Claim 12, wherein the means for moving the carriage relative to the base structure between said first and second positions are capable of halting movement of the carriage at a third position wherein the jaw arrangement is located adjacent the lubricating means whereby a sheared billet being carried by the jaw arrangement can be lubricated.

14. An apparatus as claimed in Claim 13, wherein the lubricating means is mounted to the frame via means enabling the lubricating means to be moved inwardly of the frame into contact with one end of a sheared billet being carried by the jaw arrangement when the carriage is halted at said third position.

15. An apparatus as claimed in Claim 14, wherein movement of the lubricating means when in contact with said one end of a sheared billet being carried by the jaw arrangement when the carriage is halted at said third position causes said first and second jaw members to slide relative to one another whereby the length of the lower jaw is decreased until it equals that of the carried billet.

16. An apparatus as claimed in any one of Claims 10 to 15, wherein the frame supports a pusher means which can act on the jaw arrangement whereby said first and second jaw members can be slid relative to one another to increase the length of the lower jaw to its maximum extent.

17. An apparatus as claimed in Claim 16, wherein the action of the pusher means on the jaw arrangement acts on both the upper and the lower jaw to increase the length of both to their maximum extent.

18. A billet transfer apparatus for use with a metal extrusion press substantially as described herein with reference to the accompanying drawings.