CLIAMS:1. Improvised Lathe Bed with a carriage (28) guided on a bed (1) which can be moved into z-direction by means of a spindle (20) driven by a motor (21) Characterized by the fact that two shoulders (2,3) are provided in z-direction at the outer surfaces (A, A’) of the bed opposite to one another (1) in x-direction that a linear slideway is backed up into z-direction by every shoulder (2,3) along a supporting surface (4,5) facing the carriage (28) and that the carriage (28) is fitted to the two linear slideways to be moved into z-direction

2. Improvised Lathe Bed in accordance with claim 1, whereby every supporting surface (4, 5) essentially extends over the horizontal direction from bed (1).

3. Improvised Lathe Bed in accordance with one of the Claims described hereinbefore, whereby the linear slideway is a linear guidance equipped with rolling elements.

4. Improvised Lathe Bed in accordance with one of the claims described hereinbefore, whereas the linear slideway comprises a linear slideway (6,8) fitted to a supporting surface (4,5) and a linear pilot carriage (7,9) guided on such, which is fitted to supporting leg (10, 12) on a rear side of the carriage (28) facing the bed (1).

5. Improvised Lathe Bed in accordance with one of the claims described hereinbefore, whereas the supporting leg (10, 12) features an outer surface which is essentially closed and situated at the far side of the bed (1) and an inner side which faces the bed (1).

6. Improvised Lathe Bed in accordance with one of the claims described hereinbefore, whereas a first guard plate (14, 16) is fitted to the bed (1) in a position opposite to the supporting surfaces (4, 5) which extends over the z-direction and the first free edge (15, 17) of which extend over the z-direction and engage in a first corresponding slot (11, 13) in the supporting leg (10, 12) from its inner surface.

7. Improvised Lathe Bed in accordance with one of the claims described hereinbefore, whereas a feed screw take-up leg (18) is provided at one of the supporting legs (10,12) which extends over the direction of the bed (1) through an area covered by the adjacent shoulder (2).

8. Improvised Lathe Bed in accordance with one of the claims described hereinbefore, whereas the feed screw nut (19) is arranged in the feed screw take-up leg (19) in the covered area.

9. Improvised Lathe Bed in accordance with one of the claims described hereinbefore, whereas a second guard plate (22) is attached to the one shoulder (2) which constitutes the covered area and which extends into z-direction and the second free edge (24) of which, extending over the z-direction, engages in a corresponding second slot (23) in the feed screw take-up leg (18)

10. Improvised Lathe Bed in accordance with one of the claims described hereinbefore, whereas the second slot (23) is L-shaped and the second free edge (24) is arranged in an area of the slot (23a) which runs into horizontal direction and which extends over the feed screw take-up leg (18) at one of the shoulders (2) on the far side of the feed screw (19).

11. Improvised Lathe Bed in accordance with one of the claims described hereinbefore, whereas the second guard plate (22) is provided with a third free edge (25) which runs into z-direction and which covers a first linear pilot slot between one of the linear slideways (6) and the one linear pilot carriage (7) in horizontal direction.

12. Improvised Lathe Bed in accordance with one of the claims described hereinbefore. Whereas a third guard plate (26) is attached to the other opposite shoulder (3) which runs into z-direction and the fourth free edge (27) of which running into z-direction covers a second linear pilot slot between the other linear slideway (8) and the other linear pilot carriage (9) in horizontal direction.
,TagSPECI:The invention concerns an Improvised Lathe Bed in accordance with the generic term of patent Claim 1.

In the brochure “TL Series-Lathes for Tool Design and Construction” by Messrs. Haas Automation Europe, dated 11/2004, a lathe is described, the carriage of which is fitted to the bed by way of linear slideways to be traversed into Z-direction.
A lathe of type CD 322 is known from the brochure “Lathes” by Messrs.DMT Drehmaschinen GmbH & Co.KG dated 01/2007, the carriage of which is guided by way of stepped slideways into Z-direction.

All known lathes sometimes show a resistance when the carriage travels into the Z-direction. In order to overcome such resistance, a higher force is required, a fact which complicates the operation of the lathe.

It is the task of the invention to remove the disadvantages in accordance with the state of the art, in particular, a lathe is to be described which is robust and immune to failure in practical operation.
This task is resolved by means of the characteristics of patent claim 1
Practicable designs of the invention result from the characteristics as described under patent claims 2 to 12.

In line with the invention, it is hereby suggested that
two shoulders running into-z-direction are provided at the outer surfaces of the bed opposite to one another in an x-direction that on a supporting surface of every shoulder a linear guide way is positioned and supported in Z-direction, and
that the carriage is fitted to both linear slideways to be traversed into Z-direction.

In the sense of the present invention, the term “z-direction” specifies the moving direction of the carriage. Usually, the z-direction corresponds to the mounting direction of the main spindle. The “x-direction” runs perpendicular to the z-direction. The x-direction and the z-direction make up a horizontal plane. A “y-direction” runs vertically to the x-and z-direction which corresponds to the vertical direction.

In the sense of the present invention, the term “carriage” specifically describes a tool carriage onto which a turning tool, in particular a turning chisel, a drill etc, is fitted. For example, the turning tool can be fitted to a cross slide which is mounted onto the carriage and can travel to and fro into x-direction.

In accordance with the characteristics of the invention, shoulders are provided which are positioned opposite to one another at the outer surfaces of the bed. These shoulders are equipped with linear slideways, running into z-direction. The carriage is supported by these linear slidways. As a consequence, the carriage covers the linear slideways. Thus, for example, any and all undesired chips are impeded or avoided to fall into the linear slideways. In practical operation, the suggested lathe is robust and immune to failure.

In line with an advantageous design, every supporting surface is essentially positioned in a horizontal position from the bed, i.e. the supporting surface is essentially positioned in the z-x-plane. The term “essentially horizontal” describes the fact that every supporting surface can also be provide with several horizontal planes which are separated from each other by steps. For example, an “essentially horizontal plane” is a plane that can also be tilted with reference to the z-axis by a maximum of 20 degrees, preferably by a maximum of 10 degrees at most. This makes it possible to use a standard carriage which is essentially designed in a conventional way.

Another advantageous design is that the linear slideways are provided in the form of a linear guidance equipped with rolling elements. In particular, a linear guidance system with re-circulating liner ball bearings can be used. However, the rolling elements used can also be rollers, rolls or needles. Such linear guidance equipped with rolling elements makes it possible for the carriage to be moved in particularly smooth way in relation to the bed.

In line with another advantageous design, the linear slideways comprise a linear slideway fitted to the supporting surface and a linear pilot carriage which is fitted to a supporting leg positioned on the bottom of the carriage in the direction of the bed. The linear pilot carriage usually overlaps the linear slideways. This is a further contribution to the fact that no dust, dirt or chips can fall into the area of the linear slideways.

It is an advantage if the supporting leg is provided with an outer surface positioned on the far side of the bed that is essentially closed and an inner surface positioned towards the bed. The term “an essentially closed outer surface” describes the fact that the outer surface is closed up by at least 90 percent However, one or several bores, in particular thread bores to mount further elements, can be provided in the outer surface, such thread bores are usually closed by screws screwed into them. On the bed, a first guard plate can be fitted at a position opposite to the supporting surfaces and pointing into Z-direction, the first free edges of which can engage from the inside into a corresponding first slot in the supporting leg. By engaging of the first sheet metal guard plate into the first slot in the supporting leg from the inside and by the essentially closed design of the outer surface of the supporting leg. It is furthermore avoided that dirt, dust or cutting chips can fall into the area of the linear slideways.

In line with another design, one of the supporting legs is provided with a leg to take up the feed screw nut. This leg reaches out into the direction of the bed through an area covered by the adjacent shoulder. The take-up leg for the feed screw nut is positioned in an area below the shoulder. This area is covered by the shoulder in vertical direction. This is how the ingression of chips, dust and direct into this area is avoided. It is advantageous for the feed screw nut to be arranged in the take-up leg for the feed screw nut in the covered area. The feed screw nut can be designed as a circulating ball bearing nut.

Another advantageous design provides a second guard plate into Z-direction that is fitted to one of the shoulders which simultaneously constitutes the covered area, the second free edge of which runs into the z-direction and engages into its corresponding second slot in the feed screw nut take-up leg- by means of the second guard plate, the ingression of dust, dirt or cutting chips into the area of the feed screw nut is avoided. This feature makes the suggested lathe a particularly robust lathe that is immune to failure caused by the ingression of dirt, dust or cutting chips.

It is an advantage if the second slot is designed in L-shape and if the second free edge is arranged in a slot section in horizontal direction which is positioned at a rear side on the far side of the shoulder of the feed screw nut and runs into the feed screw nut take-up leg. Apart from that the second guard plate can be provided with a third free edge, which is of advantage to run into z-direction. This sheet covers a first linear slideways slot between one of the linear slideways and the carriage on linear guides in horizontal direction. In line with this simple design, the characteristics mentioned before secure an extensive enclosure of the linear slldeways and the feed screw nut which renders the ingression of dust, dirt or cutting chips nearly impossible. In line with another version, a third sheet metal guard plate running into z-direction is fitted to the other opposite shoulder, the fourth free edge of which, running into z-direction, covers a second linear guide slot between the other linear slideway and the other linear pilot carriage in horizontal direction. This is how the other linear slideway is also protected from the ingression of dust, dirt or cutting chips in a similar way as it is the case with the other linear slideway
It is appropriate if the guard plates are made from metal, in particular from stainless steel or aluminum, or from plastic material

In the following, one example of a version of the invention is explained in detail on the basis of the drawings. The following is depicted:

Fig.1 A first perspective view of a bed unit without a carriage,
Fig.2 A second perspective view in accordance with Fig.1,
Fig.3 A perspective view of the bed unit in accordance with fig. 1 with a
carriage,
Fig.4 A second perspective view in accordance with Fig.3,
Fig.5 A sectional view as per section position A-A in accordance with Fig.1 and
Fig.6 A sectional view as per section position B-B in accordance with Fig.3
Fig. 1 and 2 are perspective views of a bed unit, Fig. 5 is a sectional view in accordance with the section position A-A in Fig.1. The headstock of the lathe is not depicted in the figures for reasons of clarity.

As is revealed by Fig. 1,2 and 5, a bed 1, which, for example, is made from cast iron is provided with two walls, running into z-direction, with two outer surfaces A and A’, located opposite to one another, From the outer surface A, there is a first shoulder 2 (Fig 5) running into x-direction, and from outer surface A’, there is a second shoulder 3(Fig 5) running into the opposite x-direction, which is running in the opposite direction to the first shoulder 2. The first shoulder 2 is provided witha first horizontal supporting surface 4 (Fig 5) and the second shoulder 3 (Fig 5) is provided with a second horizontal supporting surface 5. A first linear slideway backed up by the first supporting surface 4 comprises a first linear slideway 6 (Fig 6) and first linear pilot carriage 7 (Fig 5&6). A second linear slideway comprises surface 5 and a second linear pilot carriage 8 (Fig 5&6) backed up by the second supporting leg 10 is fitted to the first linear pilot carriage 7 (Fig 5 & 6 ) which is provided with a first slot 11 (Fig 5&6) A second supporting leg 12 (Fig 5&6) is fitted to the second linear pilot carriage 9 (Fig. 5&6) which is provided with another first slot 13 (Fig 5). The first slots 11, 13 (Fig 5) run into a z-y-plane and open up to the upper surface of the supporting legs 10, 12. (Fig 5)

A first guard plate 14 (Fig 5&6) is fitted to bed 1, positioned opposite to the first supporting surface 4 the first free edge 15 (Fig 5&6) of which engages into the first slot 11.

In a similar way, another first guard plate 16 (Fig 5&6) is mounted to the second supporting surface 5, the first free edge 17 of which engages into the additional first slot 13. The first guard plates 14, 16 are bent in a stepped way and are provided with a slant falling down from bed 1 in the direction of the corresponding supporting legs 10, 12.

A feed screw nut take-up leg 18 (Fig 5&6) is fitted to the first supporting leg 10 which extends to an area below the first shoulder 2. A feed screw nut 19 is taken up by the feed screw nut take-up leg 18, into which a spindle 20 ingresses, which is driven by a motor 21, which is advantageously a servo motor or stepper Motor.
A second guard plate 22 (Fig 5&6) is fitted to one of the free outer surfaces of the first shoulder 2, which runs into an L-shaped second slot 23, located in a feed screw take-up leg 18. The second slot 23 is provided with a horizontal section 23a which extends to an area below the feed screw nut 19. A second free edge 24 of the second guard plate 22 extends to the horizontal section 23a of the second slot 23. A third free edge 25 of the second guard plate 22 covers a first linear slideway slot which is located between the first linear slideway 6 and the first linear pilot carriage 7.

As is in particular revealed by Fig.5, the feed screw take-up leg 18 can be designed in two parts, in particular, to facilitate the making of the second slot 23 which are, for example, connected with each other by means of a screwed fastening.

A third guard plate 26 is fitted to another free outer surface of the second shoulder 3, the free fourth edge 27 of which covers a second linear slideway slot between the second linear slideway 8 and the second linear pilot carriage 9 in horizontal direction.

Fig.3 and 4 show the bed unit in accordance with Fig. 1 and 2 in a perspective view with a carriage 28 mounted to the supporting legs 10, 12.

At the top surface of bed 1 in the direction of the carriage 28, a first slideway surface 29a and a second slideway surface 29b are provided which serve to guide a tailstock (which is not shown in this picture). The first slideway surface 29a is a prismatic slideway whereas the second slideway Surface 29b is a horizontal one. The first guard plates 14, 16 are mounted to the outer surface of bed 1 by means of connecting pieces 30 in an area adjacent to the slideway surfaces 29a, 29b. the connecting pieces 30 cover, at least in parts, the supporting legs 10, 12 and the linear pilot carriage 7, 9.
The fixture functions as follows:

Carriage 28 is backed up by shoulders 2, 3 via the supporting legs 10, 12 and the linear slideways which run along the outer surfaces A, A’ of bed 1. As a consequence, carriage 28 can be moved smoothly into the Z-direction. Because of the first guard plates 14, 16, the second guard plate 22 and the third guard plate 26, the ingression of dust, dirt or cutting chips into the area of the linear slideways and the feed screw nut 19 is safely and reliably avoided.
The suggested lathe is simple in its construction, design and it is robust and immune to failure. It enables an extremely precise machining of workpieces.

Reference list
01 Bed
02 First shoulder
03 Second shoulder
04 First supporting surface
05 Second supporting surface
06 First linear slideway
07 First linear pilot carriage
08 Second linear slideway
09 Second linear pilot carriage
10. First supporting leg
11. First slot
12. Second supporting leg
13. Additional first slot
14. First guard plate
15. First free edge
16. Additional first guard plate
17. Additional first free edge
18. Feed screw nut take-up leg
19. Feed screw nut
20. Spindle
21. Motor
22. Second guard plate
23. Second slot 23a horizontal section
24. Second free edge
25. third free edge
26. third guard plate
27. fourth free edge
28. carriage 29a first slideway surface
29. 29b second slideway surface
30. Connecting piece

A, A’ outer surface