Stand frame for a roller levelling machine

A stand frame for a roller levelling machine and including spaced frame posts formed each of two spaced post members, and frame cross-piece members including cross-piece elements which connect each of the two post members forming a frame post, with each cross-piece element being connected to respective post members with hollow dowel.

BACKGROUND OF THE INVENTION 
The present invention relates to a rolling mill stand frame which includes 
stand frame posts connected by frame cross-piece elements including 
cross-beams. In particular, the present invention relates to a stand frame 
of a roller levelling machine for producing sheets, strips and profiles 
and including top and bottom rolls displaceable relative to each other and 
which are supported along their length by back-up rolls, which are 
supported on the cross-beams and are arranged in roll bearers, with the 
upper cross-beam being adjustable for positioning the levelling rolls. 
Multi-part stand frames, which includes housing posts and upper and lower 
frame cross-piece elements extending between the stand frame posts, for 
roller levelling machines, as well as for other type of rolling mills and 
presses are well known. A known stand frame includes two opposite stand 
frame posts connected by upper and lower cross-beams. In known roller 
levelling machines, the cross-beams are adjustable up and down with four 
adjusting cylinders to adjust the gap between the levelling rolls to 
different thicknesses of levelled stocks, on one side, and, on the other 
side, to adjust the relative position of the top and bottom levelling 
rolls in a direction transverse to the movement direction of the levelled 
stock. The rolling stands are also equipped with adjusting devices which 
permit adjustment of stand rolls in accordance with the thickness of the 
rolled sheet or strip. 
It is known to provide, for connection of the stand frame posts with the 
frame cross-piece elements, grooves in which connecting feather keys are 
arranged. In order to enable taking up forces generated in levellers, 
presses and rolling mills, providing of several feather key connections is 
necessary. This is because if a single groove for a feather key is used, 
it should be formed, in the stand frame post, very deep, and this results 
in an excessive weakening of the rolling mill housing. Therefore, several 
feather key connections need be formed and this, however, because of 
presence of multi-surface arrangements, makes the uniform load 
distribution very difficult. That is the generated forces cannot be 
proportionally distributed between separate feather key connections. Also, 
providing several feather key grooves and feather keys or wedges arranged 
therein results in a very adverse notch effect. 
Accordingly, the object of the invention is providing a stand frame, in 
particular, for a roller levelling machine for sheets and strips, which 
would insure a uniform load distribution by using particular connection 
joints which can be produced with low manufacturing costs. 
SUMMARY OF THE INVENTION 
This and other objects of the invention, which would become apparent 
hereinafter, are achieved by connecting the stand frame posts and the 
frame cross-piece elements with hollow dowels. Dowel connections according 
to the present invention, has many advantages in comparison with feather 
key connections. In particular, with dowel connections, a substantially 
lower notch effect is obtained, and by preferably simultaneous forming of 
the boreholes for dowels in the stand frame posts and the cross-piece 
elements, manufacturing costs are substantially reduced. The simultaneous 
forming of the boreholes in the stand frame posts and cross-piece elements 
permits to achieve a precise spacing between the dowels, which is another 
advantage of the connection according to the present invention. 
Because the hollow dowels, that is hollow bolts are used as connection 
elements, they, under the action of a load, change their cross-section to 
an oval, which permits to achieve a deformation that insures a uniform 
bearing capability of separate dowels. When, advantageously, each dowel 
connection between the stand frame post and the cross-piece element 
consists of at least two spaced dowels arranged one above the other and 
having inner bores of different diameters, the uniform distribution of the 
load for all connection positions can be optimized so that carrying 
capacity of all dowels is the same. Likewise, a equal load distribution 
for each dowel can be achieved by an appropriate selection of the 
diameters of the inner bores of the dowels if this is necessitated by the 
available profile. 
In accordance with an advantageous embodiment of the present invention, 
each dowel connection is formed of three dowels arranged one above the 
other, with the diameter of the inner bore of the dowel, which is located 
in the region of the greatest beam force, being the biggest and the 
diameter of the inner bore of the dowel, which is located in the region of 
the smallest beam force, being the smallest. Such selection of inner bore 
diameters permits to achieve a desirable force distribution on separate 
dowels. 
According to the invention, it is envisaged providing lateral screw 
connections between the stand frame posts and the cross-piece elements. 
These screw or transverse connections provide for taking up of expansion 
forces between the stand frame posts and the cross-piece elements. 
Hydraulic fastening devices can be used for screwing the stand frame posts 
with the cross-piece elements. Because dowel connections provide uniform 
distribution of forces and, thus, the same bearing capacity of all dowels, 
the screws can be made of the same size, so that the same screw thrust 
force is available.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The connection of elements of a stand frame according to the present 
invention will be explained on the basis of a roller levelling machine 
stand shown in FIG. 1. The machine stand frame of the roller levelling 
machine stand 1 of FIG. 1 includes two stand frame posts 2 and 3, which 
are anchored in a foundation and are connected by upper longitudinal and 
transverse frame cross-pieces 4a and 4' a lower frame cross-piece is not 
being designated, and upper and lower cross-beams 4, 5. Each of the upper 
and lower cross-beams 4, 5 is formed, in per se known manner, of a 
substantially rectangular element 4', 5' and a trapezoidal element 4", 5". 
Upper and lower roll bearers 6 and 7 are supported on the upper and lower 
cross-beams 4 and 5, respectively, with the lower roll bearer 7 being 
displaceable on its cross-beam 5. The upper cross-beam 4 is supported for 
displacement between the posts 2 and 3 for displacement, by adjusting 
cylinders 10, relative to the lower cross-beam. The adjusting cylinders 10 
are supported in the transverse cross-pieces 4a' in a per se known manner. 
To this end, there are provided four adjusting cylinders for the upper 
cross-beam 4, one in each corner, on the outgoing sides. 
Roll adjusting wedges 8, which are displaceable by pressure cylinders 9, 
are supported on the lower roll bearer 7. A back-up wedge 11 for the 
bottom roll 12 and its back-up roll 13, is supported on each adjusting 
wedge 8. Side bars 14 are provided between the back-up rolls 13. A 
plurality of top rolls 15 are supported, with their barrels, on back-up 
rolls 17, with side bars 16 being provided between the back-up rolls 17. 
The top levelling and back-up rolls 15 nd 17, respectively, are supported 
on a back-up wedge 18. Each of the adjacent back-up wedges 18 is supported 
by an adjusting wedge 21 the other side of which abuts the upper bearer 6. 
The top and bottom rolls 15, 12 are driven separately and are connected 
with the drive, not shown, by crankshaft 23. 
As shown in FIGS. 2 and 3, the post members 2a, 3a defining the stand frame 
posts 2 and 3 of the machine frame are connected by joints 24, formed each 
of three equally spaced from each other and arranged one above the other 
dowels 25, 26, 27, with the upper transverse cross-piece 4a' and a lower 
cross-beam 5, which serves as a lower frame cross-piece. The longitudinal 
cross-pieces 4a are connected to the posts 2, 3 by screws, as per se 
known. In order to take up expansion forces generated during operation, 
the stand frame posts 2a, 3a and the cross-elements 4a, 5 are connected 
with each other by screws 28, which are located on the outer sides of the 
housing posts 2a, 3a. As shown in more detail in FIG. 4, the dowels 25-27 
have inner bores 29-31 having different diameters. At that, the dowel 25, 
which is provided in the region of the greatest beam force has an inner 
bore 29 with the biggest diameter, and the dowel 27, which is provided in 
the region of the smallest beams force, has an inner bore 31 with the 
smallest diameter. This insures uniform force distribution with a uniform 
carrying capacity of the dowels 25-27. Thus, upon taking up of the 
generated forces by the stand frame 2, 3, the different diameters of the 
inner bores 29-31 result in different ovalities of the cross-sections of 
separate dowels, 7hich influence the load distribution. Also, due to the 
small notch effect of the dowels 25-27, a very compact connection is 
obtained. 
While the present invention was shown and described with reference to a 
particular embodiment, various modifications thereof would be apparent to 
those skilled in the art and, therefore, it is not intended that the 
invention be limited to the disclosed embodiment and/or details thereof, 
and departures may be made therefrom within the spirit and scope of the 
appended claims.