Measuring device for checking the dimensional accuracy of the track width of curved transport tracks, particularly for continuous casting or extrusion

A measuring device for checking the dimensional accuracy of the track width of curved transport tracks formed by paired rollers lying on a radius of curvature equidistantly be placed into a transport track and moved therealong, is provided with at least two displacement sensors. The sensors are spaced apart at a distance determined by the track width. The carrier for the displacement centers has contours corresponding substantially to the curvature of the transport track. The carrier has a length which ensures, when inserted in the transport track, the continuous spanning of at least two successive roller pairs. The displacement sensors are located on a radius of the circle of curvature of the track. The height of the carrier corresponds substantially to the track width, and the sensors are of the non-contact type. The carrier may be coated with elastically resilient material on those surface portions subjected to reciprocal action with the rollers.

BACKGROUND OF THE INVENTION 
The present invention relates to a measuring device for checking the 
dimensional accuracy of the track width of curved transport tracks formed 
by paired rollers lying on a radius of curvature equidistantly from each 
other. A carrier (bar) arrangemnt can be placed into the transport track 
and moved along in the transport track with at least two displacement 
pickups in the bar arrangement spaced apart at a distance determined by 
the given track width. 
Transport tracks described here are components of continuous casting or 
extrusion installations. 
To achieve high-quality semi-finished products and in the long run, 
high-quality finished products, a clearly defined track width of the 
roller sets constituting the transport track, identical dimensions of the 
track width between successive roller sets, and the maintenance of the 
initial track width are very important. 
The maintenance of the specified track width during operation requires 
continuous monitoring of the transport track. 
Previously, monitoring was carried out mainly by means of patterns, 
calipers or feeler gages under difficult operating conditions such as 
restricted space, heavy dirt and at high temperatures; dimension checking 
and the evaluation of the values obtained were time consuming. 
There is already known a measuring arrangement of the initially described 
type for continuous casting or extrusion installations where two scanning 
displacement pickups or sensors associated with a chain segment of the 
cold extrusion track, measure the distance between the rollers of each 
roller set and where the transmitted measured values are evaluated. 
This measuring arrangement which uses a straight chain segment as carrier 
for the displacement pickups does not take into consideration the 
curvature of the transport track. This results in measuring errors which 
are unacceptable in view of the high requirements on the accuracy to size 
of the track width. 
It is, therefore, an object of the present invention to provide a measuring 
device which ensures perfect checking of the dimensional accuracy to size 
of the track width of curved constant-radius transport tracks formed by 
rollers located in pairs on a radius of curvature. 
Another object of the present invention is to provide a measuring device of 
the foregoing character which is substantially simple in construction and 
may be economically fabricated. 
A further object of the present invention is to provide a measuring device, 
as described, which may be readily maintained in service, and which has a 
substantially long operating life. 
SUMMARY OF THE INVENTION 
The objects of the present invention are achieved by providing that the 
contours of the bar for the displacement pickups, at least approximately, 
correspond to the curvature of the transport track; this bar has a length 
ensuring, when inserted in the transport track, the continuous spanning of 
at least two successive roller sets; the displacement pickups are located 
on one radius of the circle of curvature. 
With a circular curvature of the transport track, the bars for the 
displacement pickups or sensors have the associate circular arc shape. If 
the transport track curvature differs from a circular arc, for example, 
with an elliptical curvature, one selects a form of curve for the bar 
which, on the one hand, ensures the unimpaired travel of the measuring 
device through the transport track and, on the other hand, minimizes the 
measuring errors occuring with straight bars. 
The construction in accordance with the present invention ensures a perfect 
measuring of the track width of such curved transport tracks. 
A preferred embodiment uses contactless displacement pickups where the 
carrier has a height corresponding to the track width. 
The forced guidance of the bar, resulting from constructing the bar in 
accordance with the track width, contributes to the measuring accuracy. 
Contactless displacement pickups are shorter; therefore, they can be 
aligned even with small track widths and are not subject to wear, thus 
eliminating additional sources of error. 
It is expedient that the height of the bar, designed for the track width, 
can be reduced, within limits, since a shifting (displacement) of the 
rollers so as to reduce the track width is definitely possible. With a bar 
(carrier) of constant height, this would lead to damage to the measuring 
device. 
With carriers with an elastic coating, a slight addition to the height can 
be provided so that the measuring device travels through the transport 
track under an initial stress securing its position in the transport 
track. 
A number of adjacent displacement pickup pairs, a distance apart, in 
addition to measuring the track width, makes it possible to measure the 
axial position and the camber of the rollers. 
With another embodiment of the present invention, the carrier has at least 
one inclinometer. This makes it possible to monitor (check) the roller 
position on the circle of curvature and, in particular, the position of 
the transport track segments in which a number of roller pairs is 
combined. Such a measuring device can also determine if the rollers are 
out of round (out of true). 
If the measuring device has a number of adjacent inclinometers at a 
distance apart, the inclinometers can also be used for checking the axial 
position of the rollers. 
A preferred embodiment provides separate inclinometer carriers with 
independently movable surface portions which engage in reciprocal action 
with the facing rollers of transport track and have, when inserted in the 
transport track under initial tension, a length ensuring continuous 
spanning of two and only two successive roller sets; inclinometers are 
mounted on these surface portions. 
The novel features which are considered as characteristic for the invention 
are set forth in particular in the appended claims. The invention itself, 
however, both as to its construction and its method of operation, together 
with additional objects and advantages thereof, will be best understood 
from the following description of specific embodiments when read in 
connection with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The curved transport track 10 in FIGS. 1 and 2 is formed by successive sets 
of rollers 11, 11', 12, 12' which are located the same track width W apart 
on radii issuing from the center of curvature, C. 
The transport track 10 is usually traveled by the continuous casting. 
To check the given track width W, the measuring device 20 in FIG. 3 is 
placed on the transport track 10 and moved along this track. 
The measuring device 20 shown in FIG. 3 comprises three curved bars 21, 21' 
and 21" (FIG. 3) which are connected by rods 22, and two bars 23, 23' with 
plane surfaces 23a, 23b. These are located between the curved bars 21, 
21', 21". The bars 23, 23' are connected to device 10 via tension elements 
24. 
The effective surfaces 21a, 21b of curved bars 21, 21', 21" are shaped with 
the curvature radii Ki and Ka. The height H of bars 21, 21', 21", 
including the elastically resilient coat 21c, 21d, corresponds to the 
given track width W of transport tracks 10 or the opening between roller 
sets 11, 11'; 12, 12' which form the transport track 10. 
Along the path of a radius R, the bars 21, 21', 21" are each assigned two 
displacement pickups or sensors 25, 25' at a distance determined by the 
track distance W. 
The displacement pickups, to check the track width, permit regulating the 
axial position and camber of the rollers. 
Between bars 21, 21', 21" for the displacement pickups, bars 23, 23' for 
two inclinometers 26, 26' are located. 
Part of the bars 23, 23' are independently movable support surfaces 27, 27' 
with an inclinometer 26 or 26' associated with each. These support 
surfaces engage in alternate (reciprocal) action with the roller sets 
forming the transport track. 
The effective surface 23a, 23b of supporting surfaces 27, 27' contacts the 
rollers of the transport track 10. These rollers are under an initial load 
28. 
By means of the inclinometers it is possible to check the roller position 
on the curvature and the relative position of the transport track segments 
to each other. In addition, it is possible to determine when the rollers 
are out of round (out of true). 
The measuring device provides virtually all pertinent information on the 
state of the transport track in a speedy manner. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic or specific aspects of this invention, and 
therefore, such adaptations should and are intended to be comprehended 
within the meaning and range of equivalence of the following claims.