DESCRIPTION This patent relates to the field of iron and steel plants and particularly regards equipments for the casting in a die by means of a press. In the case in point, this patent deals with a new press provided with a top assembly which shifts in order to facilitate the replacement of the forging die.

At present, die-forging presses for the casting at low pressure are known, these die-forging presses are assembled over the bedplate in which the forging die is lodged by means of proper stanchions.

In the lower part of said bedplate an holding furnace, from which the metal to be casted is taken, is lodged.

Said lay-out of the various components allows the casting at low pressure to be carried out optimally obtaining, in this way, perfect workpieces.

However, when the die has to be replaced so as to produce different workpieces using the same equipment, press and holding furnace, it is necessary to act sideways by means of machines such as forklift trucks which take and insert the various dies sideways, between the vertical structure supporting the press, that is, in the narrow space between the bedplate and the lower plane of the press.

The dies are fixed in the right position thanks to proper fasteners.

Said operation for replacing the dies takes long time and is even expensive, since near the low pressure casting plant suitable space is required for allowing the machine, carrying the die, to move moreover, there is the need to use forklift trucks with low precision and high carrying capacity as the dies are bulky and heavy.

In many low pressure casting plants there are lifting equipments such as chain blocks and/or crabs for lifting and moving heavy load easily but they cannot carry the sling hook of the crabs on the vertical position of the barycenter of the die, which is positionned on the bedplate, owing to the presence of the structure of the press over said die.

In order to overcome to the above mentioned drawbacks a new type of low pressure casting plant with press partially fastened and in part sideways translating has been designeted and implemented.

The new plant consists in its main parts of an elevated bedplate on which the die is fastened and under which the holding furnace is positioned, a vertical structure comprising four vertical pillars supporting upper two guide rails or horizontal paralel slides, a press unit assembled on a cart horizontally shifting.

The supporting vertical structure consists of four pillars fastened integrally to the bedplate.

On the upper part of said pillars a couple of guide rails or horizontal paralel slides are fastened, joining the tops of the couples of pillars.

Said guide rails or slides project on one of the two sides of the vertical structure for a lenght which is greater than the half distance between the two vertical pillars.

On said guide rails or slides a movable plane slides horizontally from a central position with respect to the four pillars and the die to a sideways position.

The movable plane supports the various parts of the press that is the sliding cylinders, the operating piston (s) and the press.

Some hydraulic jacks or other proper devices make the movable plane shift along the guide rails or slides.

The new plant constituted like that allow an easy replacement of the die. In fact, whenever the die has to be replaced it is sufficient to shift the movable plane with the press unit so as to make the die accessible to the hook positioned vertically on the barycenter of the die, lift the die by means of a chain block or a crab, place the new die in the same way on the bedplate and shift again the movable plane with the press unit over the vertical axis of the die in working position.

Thanks to the new plant the use of fork lift trucks with sideways access for replacing the die is not necessary, there is no need to have wide room for manoeuvre around or sideways the plant, and

it is possible to remove or place bulky and/or heavy dies with great facility and without problems.

Each couple of guide rails or slides are provided for being divided in two hinged parts so that their ends can rotate sideways the structure itself so as to reduce the laterally bulk when the plant is working.

The movable plate with the press unit can shift onward or on the right or left side according to the different needs and the different spaces available.

An improvement consists of using the shifting press unit as lifting device, and for removing and laying the die.

The press unit, and particularly the pressure plate, are equipped for hooking and supporting both parts of the die, that is the lower part as well.

Next to the whole hydraulic press there is a plane whose height is comparable to the face of the die, or a translating plane, or a lift truck which is placed side by side.

When the replacement of the die is required, the press unit dips down closing the two parts of the die which are joined with pins or hooks preset in the execution phase of said die.

The lower part of the die is released from the bedplate to which it was integral and the press unit raises lifting the whole die.

Then, the press unit shifts sideways along the guide rails or slides and dips down on the fastened plane or on the shifting plane or on

the lift truck leaning on the die which is later released from the pressure plate of the press unit.

The following die is positioned in the same discharged position of the previous die and is fastened to the pressure plate of the press unit.

At this point, the press unit shifts over the bedplate and dips down leaning the die on said bedplate.

The lower part of the die is fastened to the bedplate, the pins and the hooks joining the two parts of the die are removed, and each part of said die is now fastened the former to the bedplate and the latter to the pressure plate.

The hydraulic press is now ready for a further production with the new die.

In the case in which a crab or a chain block are available it is possible to position the new die on the bedplate, possibly preheated, while the previous die is being removed after the shifting of the press unit. In this way, the die can be replaced quickly, reducing production dead time.

The enclosed drawings present a practical execution of the invention, as an example without intent of limitation.

Figure 1 shows a side view of the plant in which it is possible to see the holding furnace (1), the bedplate (2), the die (3), the fixed pillars (4) of the vertical supporting frame, the guide rails or slides (5), the press unit (6) with the sliding cylinders (6.1), the drive piston (6.2) and the pressure plate (6.3).

Figure 2 shows the moment in which the die (3) is replaced, the moment in which the press unit (6) assembled on the movable plane (not visible in the figure) is shifted along the guide rails or slides (5) and the crab (7), with its hook, takes or places the die (3).

Figure 3 shows a schematic frontal view of the plant in which it is possible to see even the plane (8) shifting on the guides rails or slides.

Figure 4 shows a plan view in which is visible how the guide rails or the slides are divided in two parts (5.1,5.2) of which the projecting part (5.2) can rotate in order to reduce the bulk when said guide rails or slides are not necessary.

Figures 5 and 6 show how it is possible to couple the whole die (3) with the press unit (6), said press unit shifting sideways, takes the die (3) to be removed on a lateral plane (9, figure 5) or on a lift truck (10, figure 6).

Particularly, figure 5 shows how it is possible to apply quickly a new die (3) while the previous is being removed by means of a lift truck.

The above are the basic outlines of the invention, on the basis of which the technician will be able to put it into effect, any change which may be necessary upon implementation is to be regarded as completely protected by the present invention, provided that it is based on the same innovative concept described herein. Therefore, with reference to the attached drawings, the following claims are put forth.