US3221531A

US3221531A - Presses for the hot working of metal billets

Info

Publication number: US3221531A
Application number: US233372A
Authority: US
Inventors: Salter Frank Sidney
Original assignee: Loewy Engineering Co Ltd
Current assignee: Loewy Engineering Co Ltd
Priority date: 1961-10-26
Filing date: 1962-10-26
Publication date: 1965-12-07
Anticipated expiration: 1982-12-07
Also published as: GB923958A

Description

1 Dem 1965 F. s. SALTER 3,221,531

PRESSES FOR THE HOT WORKING 0F METAL BILLETS Filed Oct. 26, 1962 6 Sheets-Sheet 1 I N VENTO R F RANK SIDNEY SALTER ATTORNEYS I PRESSES FOR THE HOT WORKING OF METAL BILLE'I'S Filed on. 26, 1962 F. S SALTER Dec. 7, 1965 6 Sheets$heet 2 INVENTOR FRANK SIDNEY SALTER BY ATTORNEYS PRESSES FOR THE HOT WORKING OF METAL BILLETS Filed 001?. 25, 1962 F. S. SALTER Dec. 7, 1965 6 Sheets-Sheet 5 l NVENTOR FRAN K SIDNEY SALTER s jm w ATT ORNEYS Dec. 7, 1965 F. s. SALTER 3,221,531

PRESSES FOR THE HOT WORKING OF METAL BILLETS Filed Oct. 26, 1962 s Sheets-Sheet 4 INVENTOR FRANK SIDNEY SALTER ATTORNE YS Dec. 7, 1965 F. s. SALTER 3,221,531

PRESSES FOR THE HOT WORKING OF METAL BILLETS Filed Oct. 26, 1962 6 Sheets-Sheet 5 I20 1251.36 IZO IN V E NTOR FRANK SIDNEY SALTER ATTORNEYS Dec. 7, 1965 F. s. SALTER 3,221,531

PRESSES FOR THE HOT WORKING 0F METAL BILLETS Filed Oct. 26, 1962 6 Sheets-Sheet 6 INVENTOR FRANK SIDNEY SALTER ATTORNEYS United States Patent 3,221,531 PRESSES FUR THE HOT WGRKENG 0F METAL BELLETS Frank Sidney Salter, Parkstone, Dorset, England, assignor to The Loewy Engineering Company Limited, Bournemouth, England, a corporation of Great Britain Filed Oct. 26, 1962, Ser. No. 233,372 Ciaims priority, application Great Britain, (let. 26, 1951, 38,349/61, 38,350/61 Claims. (Cl. 72263) This invention relates to presses for the hot working of metal billets, such as for example metal extrusion presses or piercing presses, and the invention is concerned more particularly with presses of the kind in which a heated billet is supported in a container mounted on a carrier which is angularly movable to transfer the container between two stations in the press. The carrier may be rotatably mounted on one of the columns of the press, or on a separate spindle on a platen of the press.

Such presses are preferably provided with a plurality of billet containers mounted on a common carrier or on separate carriers. In ope-ration, the containers may be moved in succession between a parking station and a working station. Thus, while one of the containers is in register with the working station so that a billet can be engaged by the working tools of the press, another container is in the parking station and can be prepared for the next working operation by being freed from residue of billet metal left from the preceding operation, cleaned, lubricated if necessary, and charged with a fresh billet. In this way the waiting times between working operations can be greatly reduced with corresponding increase in the press output.

It is, however, essential that the container be accurately located on the carrier at a specified distance from the rotational axis of the carrier so that the container will be accurately centred on the working axis of the press (i.e. the axis in which the press tools are located) when in the working station. Upon continuous operation of the press, heat from the billets is transmitted to the container and carrier, and the container is displaced radially outwards due to thermal expansion of the carrier. The container in the working station will then be out of alignment with the working axis, and this will result in the production of articles of faulty configuration.

It is known to provide in conventional extrusion presses with a single container, means for ensuring that the container remains in alignment with the working axis of the press, irrespective of any thermal expansion of the container and its holder. To this end, the holder of the container has two symmetrically arranged arms, supported on two bearing surfaces on either side of the working axis of the press. These bearing surfaces extend in a radial direction with regard to the working axis. When the container holder expands under heat, the arms can slide freely over their bearing surfaces without causing the container to change its position with regard to the working axis of the press. The proper functioning of this arrangement depends on the symmetrical arrangement of the arms and the bearing surfaces with regard to the working axis of the press.

The carrier in a multi-container press is, however, arranged unilaterally with respect to the working axis of the press, and the afore-described symmetrical arrangement for compensating thermal expansion of the container holder cannot, therefore, be used.

The point at which a container-carrier is supported in the press frame is some distance from the working axis of the press. Even in the case of extrusion presses having only a moderate size this distance is considerable and may be in the order of one metre or more. An increase in temperature of the carrier in the region of 100 C. only- 3,221,531 Patented Dec. 7, 15 65 which is well within the rise of temperature to be expected during normal operations of a multiple-container press-would result in an increase in this distance in the order of one millimetre or more due to thermal expansion. The containers would then be out of alignment relative to the working axis of the press by the same amount, and this would also be the eccentricity of the extruded articles. An eccentricity of one millimetre is far outside normally acceptable limits.

According to the invention there is provided a press for hot working of metal billets and having a billet container mounted on a carrier which is angularly movable to transfer the container between two stations in the press characterised in that said carrier is formed with one or more internal cooling circuits adapted to be fed with a continuous flow of cooling liquid. In this Way the thermal expansion of the carrier can be controlled within prescribed limits.

The carrier preferably comprises a hollow casing having internal partitions forming chambers within the casing, the cooling circuit including a plurality of said chambers connected in series. In a press in which the carrier supports a plurality of containers, the carrier may be provided with a plurality of cooling circuits associated one with each container.

According to a further feature of the invention, the billet container is mounted in a compartment in the carrier, and the compartment may be provided with an internal lining co-operating with the wall of the container to form an air screen, the lining and the air screen constituting a thermal barrier which restricts transmission of heat from the container to the carrier.

The surface of the lining facing the container preferably has heat reflecting properties, for example, the side of the lining facing the container may be polished to form a heat reflecting surface and the air screen may be open to the atmosphere at its ends to permit circulation of air therethrough by convection.

The lining is preferably spaced from the wall of the compartment and co-operates therewith to form a liquid screen, the liquid screen forming part of the cooling circuit. Any heat transmitted from the container to the screen will then be conducted away by the cooling liquid.

A container is generally cylindrical and the compartment in the container holder is also preferably cylindrical, the container being mounted on a plurality of supports spaced around the wall of the compartment. The lining can then be conveniently formed by arcuate metal plates arranged one between adjacent supports and sealed around their peripheries to steps projecting radially inwards from the wall of the compartment.

The liquid screens formed between the partitions and the wall of the compartment are preferably connected in series in a primary cooling liquid circuit and the container carrier is preferably formed with a plurality of internal chambers disposed around the compartment and connected in series in a secondary coolant liquid circuit.

The primary and secondary liquid circuits may be provided with flow regulating means adjustable by thermostatic means responsive to changes in temperature in the liquid in the outlets to said circuits, so as to maintain the temperature of the liquid in the outlets substantially constant.

The liquid for the cooling circuits is preferably supplied through the hub of the carrier, one end of the hub being rotatable within a fixed distributor ring having supply and discharge conduits communicating through ducts in the end of the hub with the cooling circuits in the carrier.

The invention is particularly applicable to metal extrusion presses, and two different constructions of a multiple billet container unit according to the invention and suitable for such a press will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is an end elevation of a multiple billet container unit rotatably mounted on one of the main tension columns of an extrusion press.

FIG, 2 is a sectional end elevation of the billet container unit of FIG. 1.

FIG. 3 is a sectional side elevation taken along the line III-III of FIG. 2.

FIG. 4 is a diagrammatic view of the cooling circuits of the container unit of FIGS. l-3.

FIG. 5 is a part sectional end view of another construction of a multiple billet container unit according to the invention.

FIG. 6 is a sectional side view of part of the container unit of FIG. 5 taken along the line VI-VI.

FIG. 7 is a diagrammatic view of the cooling circuits in the container unit of FIGS. 5 and 6.

The extrusion press comprises a main frame consisting of two pressure platens interconnected by tension columns, and a main hydraulic unit mounted on one of the platens and arranged to drive a pressing stem towards a die mounted on the other platen, the axis of the pressing stem constituting the working axis of the press. The multiple billet container unit is rotatably mounted on one of the tension columns and is movable to register each container in turn with the working axis of the press. In operation, the pressing stem is entered into the bore of a container in register with the working axis and extrudes through the die a metal billet in the container bore. The main frame, the hydraulic unit, the pressing stem, and the die do not form part of the present invention and may be of any suitable conventional design.

The only parts of the press shown in FIGS. 14 of the drawings are one of the pressure platens 10, four tension columns 11, and the multiple billet container unit 12 rotatably mounted on a bearing sleeve 13 secured around one of the tension columns 11 of the press and forming a stationary support for the container unit 12. The container unit 12 comprises a carrier 14 consisting of a hollow casing having a hub 15, two large substantially cylindrical open-ended housings 16 arranged symmetrically on opposite sides of the hub 15 (FIG. 2), two small cylindrical open-ended housings 17 arranged symmetrically on opposite sides of the hub 15 with their axes lying in the plane of symmetry A-A between the housings 16, the housings 16, 17 being connected by webs to the hub 15 and positioned with their axes on a circle passing through the working axis of the press, an outer cover 18 connected by webs to the hub 15 and housings 16, 17 and two end walls 19, 211 which co-operate with the hub 15, housings 16, 17 the outer cover 18, and the webs to form chambers 21-46 within the carrier 14 as shown in FIG. 2, the webs constituting partitions within the carrier. Reference to the chambers 2140 will be made later. The carrier 14, which is preferably formed as a single unitary casting, is rotatable about the associated tension column 11 by means not shown, in order to align each of the housings 16, 17 in turn with the working axis of the press.

Each housing 17 serves as a support for a device for shearing the discard from an extruded product. The shearing device is operated by the extrusion stem of the press and is, in use, aligned with the working axis of the press. The shearing devices do not form part of the present invention and have not therefore been shown in the drawings.

The wall of each housing 16 defines a substantially cylindrical open-ended compartment and two billet containers 45 are supported on guide bars 46, 47, 48, 49 mounted in

guide slots

50, 51, 52, 53 respectively in the housing 16. The guide bars 46, 47 are arranged in the plane through the axis of the hub 15 and are a close sliding fit between the side walls of the guide slots 51), 51 and the guide bars 48, 49 are arranged symmetrically on opposite sides of this plane and are a close sliding fit with the bases of the associated guide slots 52, 53. The sides of the guide bars 48, 49 are however spaced from the sides of the associated guide slots 52, 53 to permit a limited degree of freedom of movement of the guide bars 48, 49 transversely within their associated guide slots. Each container 45 is provided with four rectangular keys 54 securely fixed in keyways in the mantle of the container and engaged as a close sliding fit in corresponding

recesses

55, 56, 57, 58 in the guide bars 4-6, 47, 46, 4% respectively, adequate clearances being provided between the keys 54, and the bottom of the

recesses

55, 56, 57, 58 to permit thermal radial expansion of the container 45 and a limited degree of freedom of movement of the container towards and away from the guide bars 46, 47.

The guide bars 48, 49 project beyond the ends of the housings 16, and the ends of the guide bars 48, 49 for the two housings are secured to the ends of four

hollow tie rods

60, 61, 62, 63 anchored to the carrier 14 at points in the plane of symmetry AA, the tie rods 61), 62 interconnecting corresponding ends of the guide bars 48 in the two housings 16, and the tie rods 61, 63 interconnecting corresponding ends of the guide bars 49 in the two housings 16. Each of the tie rods comprises two tube assemblies 64 each consisting of two tubes connected by a turnbuckle 65 and an anchor tube 66 telescoped over and secured to adjacent ends of the tube assemblies 64, the tube 66 being welded to a bracket on the carrier 14. The interiors of the two tube assemblies 64 of each tie rod are thus connected by the anchor tube 66. The turnbuckle 65 permits adjustments of the overall length of the tube assembly 64 and thereby adjustment of the distance of each container from the axis of the hub 15.

The hollow tie rods 6 l63 and the chambers 21-40 in the carrier are connected to form two separate cooling circuits which are fed with a continuous flow of cooling liquid supplied through an axial duct 67 in the hub 15 and discharged through two further axial ducts 68 in the hub 15.

The first cooling circuit comprises a tube 70 between the duct 67 and one end of the tie rod 60, the interior of the tie rod 60, a tube 71 between the other end of the tie rod 66 and one end of the tie rod 62, the tube 71 extending through the chamber 30 and being sealed in apertures in the

end walls

19, 26 of the carrier, the in terior of the tie rod 62, a tube 72 between the other end of the tie rod 62 and the chamber 21, the

chambers

21, 22, 23 interconnected by apertures in the separating webs a tube 73 between the chamber 23 and the chamber 24, the

chambers

24, 25, 26, 27 interconnected by apertures in the separating webs, a tube '74 between the chamber 27 and the chamber 28, the chambers 26', 29, 3t) interconnected by apertures in the separating webs, and a radial bore 75 in the hub communicating with a discharge duct 68. The second cooling circuit comprises a tube 86 between the duct 67 and one end of the tie rod 61, the interior of the tie rod 61, a tube 81 between the other end of the tie rod 61 and one end of the tie rod 63 the tube 31 extending through the chamber 41) and being sealed in apertures in the

end walls

19, 26 of the carrier, the interior of the tie rod 63, a tube 82 between the other end of the tie rod 63 and the chamber 31, the

chambers

31, 32, 33 interconnected by apertures in the separating webs, a tube 83 between the chamber 33 and the chamber 34, the

chambers

34, 35, 36, 37 interconnected by aper tures in the separating webs, a tube 34 between the chamber 37 and the chamber 33, the

chambers

38, 39, 40 interconnected by apertures in the separating webs, and a radial bore in the hub 15 communicating with a discharge duct 68. Each cooling circuit cools one-half of each housing 16 and one housing 17.

The two cooling circuits also contain valves 86, 87 (FIG. 4), in the

tubes

72, 82 for regulating the rate of flow of cooling liquid in the circuits.

As will be seen from FIG. 2, the entry and discharge openings for each of the chambers 21-46 are arranged at opposite ends of the chamber, whereby all the internal surfaces of each chamber are swept by the cooling liquid. The entry and discharge openings constituted by the ends of the

tubes

73, 74, 83, 84 extend into the associated chamber through a side wall thereof, so that these tubes do not project radially outwards beyond the radially outermost parts of the carrier and are not exposed to the risk of accidental damage upon rotation of the carrier.

Cooling liquid is fed to and discharged from the cooling circuits through a fixed distributor ring 88 mounted on stationary bearing sleeve 13 at one end of the hub 15. The distributor ring 83 is formed with two annular grooves, 39, 90 which communicate via radial bores with the

axial ducts

67, 68 in the hub, and liquid is fed to and discharged from the grooves 89, 911 through pipes 91, 92. The distributor ring 83 is split in the axial direction and upon assembly on the hub 15 an annular tongue 13 on the inner wall of the ring 88 engages in a co-operating annular slot in the hub and prevents rela tive axial movement between the distributor ring and the hub. The two parts of the distributor ring are secured together by an end plate 95 bolted around its periphery to the distributor ring, and having a key projecting into a slot in the stationary bearing support 13.

During operation of the press, heat is transmitted by conduction from the hot metal billets to the containers and thence, by convection, radiation, and conduction through the guide bars 46-49, to the carrier 14. Most of the heat transmitted to the carrier is however removed by the continuous flow of cooling liquid fed through the cooling circuits in the carrier so that thermal expansion of the carrier is maintained within acceptable limits.

Since moreover the guide bars 48, 49 supporting the containers are anchored by the liquid cooled rods 619-63 to the carrier at points in the plane of symmetry AA, any small degree of thermal expansion of the carrier due to the small quantity of heat not removed by the cooling liquid, will cause relative sliding of the guide bars 4%, 19 within the slots 52, 53 in the housings 16 and will not atlect the exact central position of the containers with respect to the working axis of the press.

Although in the preferred construction of the press according to the invention, the containers are mounted on a common carrier, the containers may if desired be mounted on separate carriers, each of which is movable to register the associated container with the working axis of the press. For example, two containers may be mounted one on each of two carriers pivotally mounted on the frame of the press on opposite sides of the Working axis thereof, each carrier being movable about its pivot between a position in which the associated container is in register with the working axis and a further position in which the associated container is offset from the working axis.

The container unit 1113 of FIGS. 5 and 6 is also rotatably mounted on a bearing sleeve 111 secured around a tension column 112 of the press. The container unit 111) comprises a hub 113, three substantially cylindrical openended housings 11 1 arranged symmetrically around the hub 113, each housing 114 being connected to the hub 113 by three

webs

115, 116, 117 an outer cover 118 surrounding the three housings 114, the cover 118 being connected to the housings 114 by webs 121i and to the hub 113 by webs 121, and two end walls 122 (only one of which is shown in FIG. 6 which co-operate with the hub 113, housings 115,

webs

115, 116, 117, 121i, 121 and the cover 113 to form a plurality of chambers 123 around each housing 111. The container unit is preferably formed as a single unitary casting. The container unit is rotatable about the tension column 112, by means not shown, to register each of the housings 114 in turn with the working axis of the press, and the container unit 1111 is also axially movable along the tension column 112.

Each housing 114 defines a substantially cylindrical open ended compartment, and three billet containers 124 are mounted one in each of the compartments defined by the housings. Each container 124 is provided with three rectangular keys 12S arranged symmetrically about the axis of the container and securely fixed in keyways in the mantle of the container, the radially outermost portions of the keys 125 being proud of the mantle, and each housing 11 is provided with three inwardly projecting bosses 126 having recesses 127 adapted to receive, as a sliding fit, the radially outermost portions of the keys 125. The keys 125 and bosses 126 extend the full length of the container 124 and housing respectively. The container 124 is thus accurately located in the axis of the housing 114, adequate clearance being provided between the mantle of the container 124 and the bosses 126 on the housing, and between the keys 125 and the bottom of the recesses 127 in the bosses 126, to permit thermal expan sion of the container within the housing while maintaining the container in alignment with the axis of the housing.

The compartment defined by each housing 114 is provided with a lining in the form of three arcuate metal partitions 128 which extend between the three bosses 126 on the housing 114, each partition 128 being welded on steps 1311 on the sides of the bosses 12d and on further steps 131 around the ends of the housings (only one step 131 being shown in FIG. 6). The paritions 125 are thus spaced from both the mantle of the container and the walls of the housings 114 and co-operate: with the latter to form

arcuate chambers

132, 133, 134. The partitions 123 are formed of relatively thin bright aluminum sheet, the radially inner surfaces of the paritions being highly polished. The partitions thus have a low thermal capacity and reflect back to the container 124 heat radiated therefrom. The partitions 128 may, however, consist of a sandwich of aluminum and asbestos sheeting, or they may be formed of any suitable reflecting and/or insulating material.

The three

chambers

132, 133, 134 formed between the partitions 128 and each housing are interconnected in series in a primary coolant liquid circuit by

pipes

135, 136 the pipe 135 communicating with adjacent sides of the

chambers

132, 133 and the pipe 136 communicating with adjacent sides of the chambers 133,134. The side of the chamber 132 adjacent the hub 113 is fed with coolant liquid through a pipe 137 connected to an inlet duct 133 in the hub and liquid is discharged from the side of the chamber 134 adjacent the hub 113 through a pipe 139 connected to an outlet duct 1411 in the hub.

The chambers 123 formed by the

webs

115, 116, 117, 1211, 121 between the outer cover 118, the hub 113, and each housing 114 are interconnected in series in a secondary coolant liquid circuit by apertures in the

webs

115, 117, 1211. The chamber 123 between the

webs

115, 116 is fed with coolant liquid through an inlet duct 42 in the hub 113 and liquid is discharged from the chamber 123 between the

webs

116, 117 through an outlet duct 143 in the hub 113.

The inlet and outlet ducts 138, 14-1), 142, 143 for all the liquid circuits extend axially along the hub into a cylindrical head 14 rotatable with the container unit, the head 144 having an end flange 145 secured to one of the end walls 122 of the container unit by bolts 1%, the heads of which are located in recesses in the flange 145. The head 1 14 is rotatable within a distributor ring 147 which is keyed to the bearing sleeve 111 on the column 112 by a tongue 148 on a plate 149 bolted to the ring 147, the tongue 148 engaging in an axial slot 1511 in the sleeve 111. The distributor ring 147 is split in the axial direction, and upon assembly on the head 144 an annular tongue 151 on the inner wall of the ring 147 engages within an annular slot 152 on the head 144 and prevents relative axial movement between the ring 147 and head 144.

The inner wall of the distributor ring 147 is formed with four axially spaced

annular grooves

155, 156, 157, 158 which communicate with the

ducts

138, 142, 140, 143 respectively via radial bores in the head 1441, and communicate also with flexible pipes 159, 161), 161, 162 respectively via radial bores in the distributor ring. Coolant liquid for the three primary circuits are thus fed through the pipe 159 and discharged through the pipe 161, and coolant liquid for the three secondary circuits are fed through the pipe 160 and discharged through the pipe 162. Leakage of liquid along the inner wall of the distributor ring 147 is prevented by annular rubber seals 163 located at the sides of each

groove

155, 156, 157, 158 and compressed between the head 144 and distributor ring 1417.

The rate of circulation of liquid through the primary and secondary circuits is regulated in response to the quantity of heat absorbed by the liquid in a manner now to be described with reference to FIG. 7 which shows a schematic arrangement of the primary and secondary liquid circuits associated with one of the housings 114.

Referring to FIG. 7, the primary circuit comprises the three

arcuate chambers

132, 133, 134 connected in series by the

pipes

135, 136, an inlet pipe 165 connected through the flexible pipe 159 (not shown in FIG. 7) to the duct 138 leading to chamber 132, and an outlet pipe 166 connected through the flexible pipe 161 (not shown in FIG. 7) to the duct 140 leading away from the chamber 134. The secondary circuit comprises the chambers 123 connected in series, an inlet pipe 167 connected through the flexible pipe 160 (not shown in FIG. 7) to the duct 142 leading to the first of the chambers 123 and an outlet pipe 168 connected through the flexible pipe 162 (not shown in FIG. 7) to the duct 143 leading away from the last of the chambers 123. The

inlet pipes

165, 167 are supplied through a common manually operated shut-off valve 169.

The inlet pipe 165 for the primary circuit is provided with a flow regulated valve 170 adjustable by a solenoid 171 and a thermocouple 172 extends into the outlet pipe 166, the output from the thermocouple 172 being fed through an amplifier 173 to the solenoid 171. The arrangement of the valve 170, solenoid 171, thermocouple 172 and amplifier 173 is such that the rate of flow of liquid in the primary circuit is increased or decreased upon increaseor decrease of the temperature of the liquid discharged through the outlet pipe 166, whereby the temperature of the liquid in the

chambers

132, 133, 134 remains substantially constant. Similarly, the temperature of the liquid flowing through the chambers 123 of the secondary circuit is maintained substantially constant by a flow regulating valve 174 in the inlet pipe 167 which is adjusted by a solenoid 175 operated by an amplifier 176 fed by a thermocouple 177 extending into the outlet pipe 163.

Transmission of heat from each container 124 to the associated housing 114 is restricted by a thermal barrier consisting of the partitions 128, the radially inner surfaces of which are polished to reflect back to the container heat radiated therefrom, and an air screen formed by the space between the container 124 and the partitions 128.

The air screen is open to the atmosphere at its ends and heating of the air in the air screen by the container will, due to convection of the air, result in a steady flow of air through the air screen. An appreciable proportion of the air in the screen heated by the container escapes through the open ends of the screen and is replaced by cold air, so that the temperature of the air in the screen remains comparatively cool and transmission of heat from the air to the partitions is thereby re- 8 duced. The

arcuate chambers

132, 133, 134, which are fed with a steady stream of coolant liquid, form a liquid screen which removes heat absorbed by the partitions.

Some heat will nevertheless be transmitted from the container 124 to the housing 114 through the keys and bosses 126 supporting the container within the housing, and otherwise. The heat transmitted through the bosses 126 is however restricted by the relatively small cross-section of the bosses 126, and this heat, together with any small quantity of heat transmitted across the liquid screen, is removed by the flow of coolant liquid through the chambers 123 of the secondary circuits surrounding the housing. The rate of flow of liquid in the liquid screens and in the chambers 123 is regulated by the quantity of heat absorbed by the liquid screen and the chambers 123, so that the thermal expansion of the container unit, due to the heat transmitted from the containers, can be controlled within limits inside the prescribed tolerances for extruded articles.

The air screen may be sealed at its ends by resilient packing between the container and the partitions. This has the advantage of further restricting loss of heat from the container, but the increase in the temperature difference between the air in the air screen and the partitions causes a rise in temperature of the partitions and of the coolant in the liquid screens, and consequently a rise in the temperature of the housing 114. The container unit is therefore preferably designed to permit the minimum loss of heat by escape of air from the air screen, which will allow the thermal expansion of the container unit to be maintained within the prescribed tolerances for extruded articles by the primary and secondary cooling circuits.

What I claim is:

1. A metal extrusion press having at least two billet containers, means for rotating said containers about an axis parallel to the main working axis of the press, whereby the containers are transferred from a position in this axis to a position outside theref, said rotating means comprising a carrier common to said containers and a stationary support in said press extending parallel to the main working axis, said carrier having a central hub by which it is mounted on said support, cylindrical housings radially spaced apart from said hub and each supporting a container, an outer cover spaced apart from said housings, and a cooling system for said housings for circulating a coolant through the space between said housings and said outer cover, and means for supplying and discharging a coolant to the space between said housings and said outer cover including inlet and outlet ducts in the hub part, and inlet and outlet ducts on the stationary support, the latter ducts being in registry with the former ducts.

2. A metal extrusion press according to claim 1, in which partitions extend from the container housings to the outer cover, said partitions forming chambers surrounding said container housings and being connected to each other in series to form a cooling circuit.

3. A metal extrusion press according to claim 1, in which a separate cooling circuit is provided for each container housing.

4. A metal extrusion press according to claim 1, in which a cooling circuit is provided for more than one container housing.

5. A metal extrusion press having at least two billet containers, means for rotating said containers about an axis parallel to the main working axis of the press, whereby the containers are transferred from a position in this axis to a position outside thereof, said rotating means comprising a carrier common to said containers and a stationary support in said press extending parallel to the main working axis, said carrier having a central hub by which it is mounted on said support, cylindrical housings radially spaced apart from said hub and each supporting a container, an outer cover spaced apart from said housings, and a cooling system for said housings for circulating a coolant through the space between said housings and said outer cover, and means for supplying and discharging a coolant through said hub and said stationary support, said carrier for said containers having auxiliary devices mounted thereon, the auxiliary devices alternating with said containers around the periphery of said carrier, said carrier having separate internal housings for each of the auxiliary devices, and said outer cover surrounding and spaced apart from the housings of both said containers and said auxiliary devices, and cooling circuits fed from the hub of said carrier, said circuits being arranged in parallel with each other and providing for the circulation of a coolant through the space between said housing and said cover.

6. A metal extrusion press according to claim 5, in which a cooling circuit includes part of the space around one container housing, the space around an auxiliary device and part of the space around another container housing.

7. A metal extrusion press having at least two billet containers, means for rotating said containers about an axis parallel to the main working axis of the press, whereby the containers are transferred from a position in this axis to a position outside thereof, said rotating means comprising a carrier common to said containers and a stationary support in said press extending parallel to the main working axis, said carrier having a central hub by which it is mounted on said support, cylindrical housings radially spaced apart from said hub and each supporting a container, an outer cover spaced apart from said housings, and a cooling system for said housings for circulating a coolant through the space between said housings and said outer cover, and means for supplying and discharging a coolant to the space between said housings and said outer cover, including a cooling circuit for more than one container housing in which a cooling circuit comprises one half of the space surrounding one container housing and one half of the space surrounding another container housing.

8. A metal extrusion press having at least two billet containers, means for rotating said containers about an axis parallel to the main working axis of the press, whereby the containers are transferred from a position in this axis to a position outside thereof, said rotating means comprising a carrier common to said containers and a stationary support in said press extending parallel to the main working axis, said carrier having a central hub by which it is mounted on said support, cylindrical housings radially spaced apart from said hub and each supporting a container, an outer cover spaced apart from said housings, and a cooling system for said housings for circulating a coolant through the space between said housings and said outer cover, and means for supplying and discharging a coolant to the space between said housings and said outer cover, in which two containers are arranged diametrically opposite each other with regard to the axis of rotation of the carrier and in which hollow tie-rods are anchored to the housings of said containers for maintaining said containers at a predetermined distance from each other, the interior of said hollow tierods forming part of a cooling circuit which includes the space around said housings.

9. A metal extrusion press having at least two billet containers, means for rotating said containers about an axis parallel to the main working axis of the press, where by the containers are transferred from a position in this axis to a position outside thereof, said rotating means comprising a carrier common to said containers and a stationary support in said press extending parallel to the main working axis, said carrier having a central hub by which it is mounted on said support, cylindrical housings radially spaced apart from said hub and each supporting a container, an outer cover spaced apart from said housings, arcuate partitions radially spaced apart from the containers and their housings respectively, and in which the spaces between a partition and a housing and a partition and the outer cover form part of a cooling circuit which is fed from the hub part, and a cooling system for said housings for circulating a coolant through the space between said housings and said outer cover, and means for supplying and discharging a coolant to the space between said housings and said outer cover.

iii). A metal extrusion press having at least two billet containers, means for rotating said containers about an axis parallel to the main working axis of the press, whereby the containers are transferred from a position in this axis to a position outside thereof, said rotating means comprising a carrier common to said containers and a stationary support in said press extending parallel to the main working axis, said carrier having a central hub by which it is mounted on said support, cylindrical housings radially spaced apart from said hub and each sup porting a container, an outer cover spaced apart from said housings, arcuate partitions radially spaced apart from the containers and their housings respectively, and in which the spaces between a partition and a housing and a partition and the outer cover form part of a cooling circuit which is fed from the hub part, and in which a container is supported on a plurality of ribs projecting radially from a container housing, and in which said arcuate partitions are attached to said ribs, and a cooling system for said housings for circulating a coolant through the space between said housings and said outer cover, and means for supplying and discharging a coolant to the space between said housings and said outer cover.

References Cited by the Examiner UNITED STATES PATENTS 2,385,574 9/1945 Hyprath 207-16 2,740,519 4/1956 Sparks 207--16 2,820,132 1/1958 Krause 20716 3,070,391 12/1962 Hofman 207-15 3,083,827 4/1963 Rosenthal 207-15 FOREIGN PATENTS 902,122 1l/ 1944 France. 523,384 7/ 1940 Great Britain.

OTHER REFERENCES Hydraulik G.m.b.H., 1,051,771, March 1959, German application.

WILLIAM J. STEPHENSON, Primary Examiner.

CHARLES W. LANHAM, MICHAEL V. BRINDISI,

Examiners,

Claims

1. A METAL EXTRUSION PRESS HAVING AT LEAST TWO BILLET CONTAINERS, MEANS FOR ROTATING SAID CONTAINERS ABOUT AN AXIS PARALLEL TO THE MAIN WORKING AXIS OF THE PRESS, WHEREBY THE CONTAINERS ARE TRANSFERRED FROM A POSITION IN THIS AXIS TO A POSITION OUTSIDE THEREOF, SAID ROTATING MEANS COMPRISING A CARRIER COMMON TO SAID CONTAINERS AND A STATIONARY SUPPORT IN SAID PRESS EXTENDING PARALLEL TO THE MAIN WORKING AXIS, SAID CARRIER HAVING A CENTRAL HUB BY WHICH IT IS MOUNTED ON SAID SUPPORT, CYLINDRICAL HOUSINGS RADIALLY SPACED APART FROM SAID HUB AND EACH SUPPORTING A CONTAINER, AN OUTER COVER SPACED APART FROM SAID HOUSINGS, AND A COOLING SYSTEM FOR SAID HOUSINGS FOR CIRCULATING A COOLANT THROUGH THE SPACE BETWEEN SAID HOUSINGS AND SAID OUTER COVER, AND MEANS FOR SUPPLYING AND DISCHARGING A COOLANT TO THE SPACE BETWEEN SAID HOUSINGS AND SAID OUTER COVER INCLUDING INLET AND OUTLET DUCTS IN THE HUB PART, AND INLET AND OUTLET DUCTS ON THE STATIONARY SUPPORT, THE LATTER DUCTS BEING IN REGISTRY WITH THE FORMER DUCTS.