This invention relates to a shapemeter for continuously detecting and indicating the shape of metallic strips during a rolling operation. The invention also orovides a rotor module for such shapemetsr.

In the rolling of metallic strip "shape" means a variation in width-wise tension when the strip is held in lengthwise tension. Thus "shape" refers to deviations of flatness of the strio in more than one direction. Poor flatness or "shaoe" results from imperfect rolling at an earlier stage and, unless remedial action is taken, is manifested in the finished product. By using a shapemeter lack of flatness may be detected and remedial action taken during the rolling operation.

A shapemeter usually has a number of concentric rotary sleeves arranged transversely to the passline of the strip and engaged under tension by the moving strip which is arranged to have a small "wrap" around the sleeves. Variations in shape are detected by sensing the load applied to individual sleeves, an instantaneous display of these individual loads indicating the flatness profile or shape of the strip then in contact with the shapemeter. Signals from the shapemeter representative of these individual loads may be used to control automatically the rolling operation, as by varying roll profile, or the degree and location of bad shape as indicated by the display may be interpreted to effect manual control of the rolling operation.

Numerous designs of shapemeters have been proposed in the past and some, such as that described in U.K. patent 1160112 are in successful use. In most earlier constructions the sleeves are carried on a mandrel and supported on air or roller bearings and the relative

deflections of the sleeves are detected either by sensing changes in air pressure or by the use of other forms of load detector.

All existing shapemeters require very high tolerances to be maintained during construction resulting in very expensive instruments. Furthermore most current designs limit the minimum width to which a rotor can be manufactured thus limiting the number of rotors for a particular axial length of shapemeter and this, in turn, limits the resolution of measurement.

It is an object of the present invention to provide a shapemeter of simplified construction that does not require high tolerances during manufacture and that enables narrow rotors to be constructed. A further object is to provide an improved rotor module for such a shapemeter.

Our copending application No. , shows one design of rotor module and shapemeter; the present invention provides an alternative arrangement.

According to one aspect of the present invention there is provided a rotor module for a shapemeter comprising a central arbor linked to a non-rotatable ring surrounding the arbor by at least one web and an outer cylinder rotatable on bearings on the ring and means carried by the arbor to cooperate with the inner surface of the ring to detect relative movement between the arbor and the ring in response to a force applied to the cylinder at a predetermined position in order to provide output signals representative of such movements. The means may be carried by the web and detect bending thereof in response to said movements. Alternatively the means may detect a variation in a gap between the ring and the arbor at a location adjacent the predetermined position.

According to another aspect of the present invention there is provided a shapemeter comprising a plurality of rotor modules according to the preceding paragraph having their arbors joined together so that the cylinder of each module are concentric.

The above and other aspects of the present invention will now be described by way of example with reference to the accomDanying drawings in which:-

Figure 1 is a side view of a shapemeter,

Figure 2 is a section on the line II-II of Figure 1 to a larger scale and

Figure 3 is a part section on the line III-III of Figure 2.

Referring to the drawings a shapemeter, indicated generally at 1 , comprises a series of rotor modules 2 ^• carried between end plates 3 having trunnions 4 carried by supports 5 on a carrier beam 6.

Each module 2 has a stationary arbor 7 of dumbell shape formed with a central bore 8, joined by opposed webs 9 to a ring 10 whic is spaced from arcuate surfaces 11 on the arbor 7. An outer cylinder 12 is rotatable on roller bearings 13 carried by the ring 10.

A plurality of modules are joined axially by bolts 1 passing through the end plates 3 _» and the -arbors 7 , so that the assembly is rigidly mounted with each outer cylinder separately rotatable. It will here be understood that the axial lengths of each cylinder 12 are slightly less than the axial lengths of the arbors 7 so that the cylinders are freely rotatable.

As shown in Figure 2 the shapemeter is mounted so that a rolled strip 15 passes under tension over the cylinders

12. Each cylinder is therefore subjected to a vertical load which causes the webs 9 to bend and narrows the gap between the inner surface of the ring 10 and the adjacent surface 11. This movement may be measured by sensors such as 16 carried by the arbor 7. The sensors may, for example, detect a change in capacitance between the inner surface of the cylinders 12 and the surface 11. Alternatively strain gauges 17 may be provided on the webs 9.