Measuring and testing – With fluid pressure – Dimension – shape – or size
Patent
1998-05-19
1999-11-16
Raevis, Robert
Measuring and testing
With fluid pressure
Dimension, shape, or size
73 378, G01B 1304
Patent
active
059837071
DESCRIPTION:
BRIEF SUMMARY
The present invention is concerned with the construction and operation of shapemeters and particularly the rotor of a shapemeter for sensing the shape of an elongate strip of material in a process line, for example a line for rolling metal strip, plastics or paper. During rolling the strip is subject to tension and pressing by the action of rollers. If the tension or pressing applied to the strip is not uniform across the width of the strip the thickness and length of the strip will be non-uniformly altered across its width resulting in flatness defects, waste and consequent loss of productivity. It is therefore necessary to sense the shape of the strip in the line.
FIGS. 1 and 2 illustrate a prior art shapemeter, while
FIG. 3 illustrates the invention.
A form of prior art shapemeter is illustrated in FIG. 1 and is sometimes known as a "vidimon" (registered trade mark) shapemeter. This shapemeter comprises a fixed arbor 1 upon which several rotors 2 of similar diameter are mounted along its axis. The arbor 1 includes a manifold to distribute compressed air to air feed jets 3 and so to an annular space 4 between the arbor 1 and the inner surface of each rotor 2 to form an air bearing. In use the outer surface of each rotor is carried into contact with a surface of the strip as the strip moves longitudinally through the line. Any change in the length of a width portion of the strip changes the position of the rotor 2 engaged with that portion of the strip and causes a corresponding change in the pressure of the air cushion supporting that rotor. This pressure change is sensed by transducers connected to air pressure measuring ports 5 via an air sensing loom in the arbor. The sensed air pressure is signalled to a data processor and this data may then be used to control process parameters in the line such as roll profile to rectify any undesired deformation of the strip.
FIG. 2 shows a conventional rotor 2 for a shapemeter. The conventional rotor 2 is formed from an inner annulus 6 and an outer annulus 7 . This allows the inner annulus 6 to be formed of a soft material which will not damage the arbor 1 if the air supply to the bearing fails so that the rotor 2 contacts the arbor 1 at speed. The inner and outer annuli are secured together by means of an interference fit 8 at their axial ends. This allows a thermally insulating space 9 to be formed between the inner and outer annuli and so to improve the thermal stability of the rotor.
The speed of strip process lines has increased substantially since the development of the conventional shapemeter described above. In consequence the sensitivity demanded of shapemeters in modern lines has also increased. There is now a demand for a shapemeter of improved sensitivity and thermal stability.
Accordingly the present invention provides a rotor for a shape meter comprising an inner annulus and an outer annulus, said annuli being coaxially engaged by at least two O-rings engaging coaxially in a space formed between the outer surface of the inner annulus and the inner surface of the outer annulus.
Further according to the present invention there is provided a shapemeter comprising a rotor according to the preceding paragraph.
The use of o-rings to connect the inner and outer annuli of the rotor allows the rotor to be formed with a reduced thermal conductance between the inner and outer annuli. Ordinarily the o-rings will be the only contact between the inner and outer annuli. Because of the thermal stability provided by the rotor according to the invention the shapemeter can have the same calibration characteristics over its full working temperature range.
For the purpose of this specification the term o-ring is to be understood to include not only continuous rings of constant cylindrical section but also rings of non-cylindrical section, such as triangular, square or more complex section.
The prior art annuli needed to have similar thermal properties to avoid intolerable thermal stresses during use. The thermal barrier provided by the use of the o-rings allows materials
REFERENCES:
patent: 2977788 (1961-04-01), Minix
patent: 3154939 (1964-11-01), Dabanian et al.
patent: 4967465 (1990-11-01), Frank
Kvaerner Technology & Research Ltd.
Raevis Robert
LandOfFree
Rotor for a shapemeter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rotor for a shapemeter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rotor for a shapemeter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1309998