Extrusion Presses

Abstract

An extrusion press in which the prime movers for a rotatable die carrier and/or container carrier are arranged upstream of the billet lubrication equipment and preferably upstream of the main cylinder crosshead.

Description

This invention relates to an extrusion press for metals including drive means for a rotatable die or container carrier and suitable for the production of rods, sections or tubes.

In such presses, a billet is placed in a container or pressure chamber and a pressing stem acting under the influence of external means, commonly an hydraulic ram, forces the billet material through a die, placed at the end of the container bore. The die is mounted in a die carrier which may be arranged to either slide or rotate transversely to the axis of extrusion. Furthermore, the container is also mounted in a container holder, and in certain instances, particularly in the case of high production presses, it is convenient to incorporate two or more containers within the press design, mounted in a holder arranged to rotate about a convenient point thus bringing each container to the press centreline as required by the demands of the press cycle. The die and container carriers may also be designed to permit axial movement, if required.

It is known to have drive arrangements for the rotatable die and container carriers in extrusion presses in which the gear box and drive motor are disposed in close proximity to the respective carriers. Because the drive arrangements are arranged in this position, they are also close to the billet loading and lubrication equipment which can lead to contamination problems. This is particularly true in steel extrusion presses where lubricating material such as glass powder is used which can pass into the drive arrangements and thereby cause defective operation.

Furthermore, the size of these known drive arrangements are such that they occupy a considerable amount of space in areas where ease of access to other components of the press is important for maintenance purposes.

It is an object of this invention to overcome these problems, and according to the present invention there is provided an extrusion press including a die assembly carrier, a container assembly carrier and billet lubrication means arranged adjacent to the latter, drive means being provided for rotating one of the carriers to bring an assembly into the centerline of the press and including a drive shaft one end of which is operatively connectible to the rotatable carrier and the other end of which is connectible to a prime mover, the latter being arranged upstream of the lubrication means and spaced sufficiently therefrom substantially to reduce, in use, contamination thereof by lubricating material.

Preferably, the prime mover is arranged upstream of the main cylinder crosshead of the press.

The downstream end of the drive shaft may be operatively connected by spur and pinion gearing to the rotating carrier.

Drive means may also be provided for rotating the other carrier to bring an assembly into the centreline of the press, the features of the said one carrier and its associated drive as itemised above being equally applicable to the other carrier and its drive means.

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawing of which:

FIG. 1 is a diagrammatic, part-sectional, plan view of part of a steel extrusion press taken on the line I--I of FIG. 2; and

FIG. 2 is a section taken on the line II--II of FIG. 1.

Referring to the drawing, the press includes a main crosshead 1, supporting a hydraulic cylinder 2, and a platen 3 joined to the crosshead 1 by four columns 4. A two-station rotatable container carrier 5 incorporating containers 5' and 5" and a three-station rotatable die carrier 6 are positioned adjacent to the platen 3 and are securely supported on respective sleeves 7 and 8. As shown in the drawings, the carriers are formed separately from their respective sleeves but they could be formed integrally therewith. The sleeves are rotatably supported by bearings on the columns and are also capable of limited axial movement along the columns. Axial movement of the sleeves 7 and 8 is facilitated by respective pairs of shift cylinders 9 and 10 mounted on the main crosshead 1. The piston rods 11, 12, of these cylinders are secured to and effect axial movement of crossheads 13, 14, respectively, the sleeves 7 and 8 being freely rotatable but axially fixed relative to the crossheads 13, 14. A cylinder/ram assembly 15 for billet loading and a lubrication assembly including a table 16 are also provided. In use, a layer of glass powder is sprinkled onto the table 16 and a billet is then rolled across the latter to pick up a coating of the powder. The cylinder/ram assembly 15 is then actuated to move the billet into the container 5". The lubrication assembly is the main source of contamination and of necessity it is positioned in close proximity to the carriers.

The sleeve 7 is operatively connected by spur and pinion gearing 17 to one end of a shaft 18, the other end of the shaft being connected to an electric motor 19 via a gear box 20. Similarly, the sleeve 8 is operatively connected by spur and pinion gearing 21 to one end of a shaft 22, the other end of the shaft being connected to an electric motor 23 via a gear box 24. Both sets of gear boxes and motors are mounted behind the main cylinder crosshead assembly, clear of the central working area and of the centre of the press.

It will be understood that whilst reference has been made in the above description to extrusion presses incorporating rotating carriers for both containers and die assemblies, the invention is not so limited but is applicable to presses including a single rotating carrier for either the container assemblies or the die assemblies.

Furthermore, whilst reference has been made to a steel extrusion press where lubrication problems are particularly prevalent, it will be appreciated that the invention covers extrusion presses generally.

It will be appreciated that the arrangement described above not only reduces contamination of the drive motors by lubrication material but also considerably improves access to the press working area for maintenance and tool changing purposes, etc. These advantages would not be obtained simply by shielding the known drive arrangements, in which the drive motors are arranged close to the rotatable carriers, in a protective casing. Thus, firstly, such a casing would necessarily reduce access to the press working area still further and it is not, in any case, as effective for preventing ingress of lubricating material to the drive motors. Moreover, these advantages would not be gained by arranging the drive motors behind the main platen of the press because they would then interfere with the run-out system and would prevent, or make difficult, access to the back of the platen for inspection or other purposes.

Claims

I claim:

1. An extrusion press including a die assembly carrier, a container assembly carrier and billet lubrication means arranged adjacent to the latter, drive means being provided for rotating one of the said carriers to bring an assembly into the centreline of the press and including a drive shaft one end of which is operatively connectible to said one carrier and the other end of which is connectible to a prime mover, said prime mover being arranged upstream, relative to the direction of extrusion, of said lubrication means and spaced sufficiently therefrom substantially to reduce, in use, contamination thereof by lubricating material.

2. An extrusion press as claimed in claim 1, in which said prime mover is arranged upstream, relative to the direction of extrusion, of the main cylinder crosshead of the press.

3. An extrusion press as claimed in claim 1, in which the downstream end, relative to the direction of extrusion, of said shaft is operatively connected by spur and pinion gearing to said one carrier.

4. An extrusion press as claimed in claim 1, in which further drive means are provided for rotating the other carrier to bring an assembly into the centreline of the press, said further drive means including a drive shaft one end of which is operatively connectible to said other carrier and the other end of which is connectible to a prime mover, said prime mover being arranged upstream, relative to the direction of extrusion, of the lubrication means and spaced sufficiently therefrom substantially to reduce, in use, contamination thereof by lubricating material.