DEVICE FOR MEASURING THE DEFLECTION OF ELONGATE COMPONENTS

DISPOSITIF SERVANT A MESURER LA DEVIATION D'ELEMENTS ALLONGES

English Abstract

ABSTRACT
The invention concerns a device for determining the
distortions of elongate components with a longitudinal axis. The
invention is characterized by a transmitter of electromagnetic
radiation including light waves, which at least in an axially
parallel plane approximately in the center (at one-half of its
length) of the component is attached to its outside or firmly
connected with it, and through pickups for the electromagnetic
radiation, including light waves, that are arranged in the same
axial line with these, outside on the ends of the component, the
sensor surface of which pickups, sensitive to the radiation,
features sensor elements which are distributed in the way of a
faceted eye.

Claims

WHAT IS CLAIMED IS:
1. Device for measuring the deflection of an elongate component
supported on both ends and having a longitudinal axis, said device comprising:
at least one transmitting unit having means for transmitting a
pair of signals each in the form of a sharply focused energy beam, said transmitting
unit being connected firmly with the elongate component at approximately the
center thereof such that the beams extend in opposite directions essentially parallel
to the longitudinal axis of the elongate component and toward the respective ends
of me elongate component;
two receiving units each arranged on a respective end of said
elongate component and axially aligned with one another and with said transmitting
unit, each receiving unit receiving a transmitter signal only from one directionrelative to the ends of the elongate component, each receiving unit having a
number of sensors arranged in at least one row, with the row extending in the
direction of deflection of the elongate component;
said transmitting and receiving units being arranged such that at
a condition of zero detection of the elongate component, each of the transmittedsignals per receiving unit will be received by a zero sensor of the row of sensors of
the respective receiving unit, and that at a condition of non-zero detection that
receiving unit whose sensor excited by the respective transmitter signal is at agreater distance from the respective zero sensor, relative to the excited sensor of
the other receiving unit, emits a correspondingly stronger detection signal; and at least one of either a summing device and an averaging
device to sum or average, respectively, the detection signals from each receiving
unit in a given direction of deflection.
2. Device according to Claim 1, in which said electromagnetic
radiation is laser light.

3. Device according to Claim 1, including two transmitting units
arranged back to back at approximately the center of said elongate component, each
transmitting unit interacting with only one of said receiving units.
4. Device according to Claim 1, in which each receiving unit
includes several juxtaposed rows of sensors arranged as a faceted eye.
5. Device according to Claim 3, in which each receiving unit
includes several juxtaposed rows of sensors arranged as a faceted eye.
6. Device according to Claim 5, in which the detection of the
component is determined in two directions that are perpendicular to each other.
7. Device for measuring the detection of an elongate component
with a longitudinal axis, specifically a beam supported on both ends, comprising:
a transmitting unit which at least in an axially parallel plane, in
approximately the center of the component, is firmly connected with the outside of
said elongate component, which transmitting unit emits sharply focused
electromagnetic radiation;
a receiving unit responsive to electromagnetic radiation which
is arranged in axial alignment with said transmitting unit outside on the ends of the
elongate component, said receiving unit having a sensor surface sensitive to theradiation and including at least one row of sensor elements which are distributed in
the manner of a faceted eye, with the row extending in the direction of the
detection; and
at least one of either a summing device and an averaging
device to sum or average, respectively, the deflection signals from the receiving
unit in a given direction of deflection.
8. Device according to Claim 7, in which said electromagnetic
radiation is laser light.

Description

2 ~ 5 9 3
-`` DEVICE FOR MEASURING THE DEFLECTION OF ELONGATE COMPONENTS
.~:
; The invention concerns a device for measuring the deflection
` of elongate components, specifîcally of a beam supported on both
ends, such as a support beam for the scraper blade of a paper
coater or for the upper lip of a paper machine headbox.
,
Elongate components in various machine construction areas,
specifically support ~eams which are preferably formed of metal,
often are subject to stress by static forces, but also are
subject to stresses by thermal forces due to temperature
differences. The latter often lead to heavy distortions of
elongate components.
,; .
The problem underlying the invention is to determine the
extent of these distortions or deflections. This problem is
inventionally solved by the features of the present invention in
a device of the type initially cited above.
"j .
A device for measuring the deflection of an elongate
component with a longitudinal axis, specifically a beam supported
on both ends, includes a transmitting unit which is firmly
connected wi'h the outside of the elongate component in
approxlmately the center thereof, which transmitting unit emits
sharply focused electromagnetic radiation. A receiving unit
responsive to electro~agnetic radiation is arranged in axial
alignment with the transmitting unit outside on the ends of the
elongate component, and has a sensor surface sensitive to the
radiation and including at least one row of sensor elements which
are distributed in the manner of a faceted eye, with the row
extending in the direction of the deflection.
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~ 326593
The invention will be explained hereafter with the aid of
~he embodiment illustrated in the drawings.
Fig. 1 is an elevational view of an elongate component
incorporating an ~mbodiment of the present invention.
Fig. 2 is a diagrammatic sketch showing the conditions of
deflection of the elongate component of Fig. 1.
,~
Referring to FIGS. 1 and 2, the beam 1 sketched as an
elongate component rests on lateral supports 2 and 3. As
:
indicated, its straight axis C, indicated by the dash-dot line,
;~ is deflected by mechanical defects so as to form the axis C'
~ indicated by the dash-double dot line. Installed on the beam
. .
through the intermediary of brackets, in its center, i.e., at
one-half of its length, is a transmitting unit 4 for
electromagnetic radiation or light, including laser light, and on
the two ends of the beam, receiving units (pickup 5 and 6) for
the electromagnetic radiation or light. The electromagnetic
radiation or light is indicated by the arrows marked L. The
pickups have a sensor surface on which sensor elements 5' or 6'
are distributed ln the way of a faceted eye. These are able to
determine the degree of center axis distortion according to the
distorted center axis C', on the basis of the inclination of the
rays L that exists then relative to the undistorted center axis
C. There may as well be provided only a single row of sensor
elements, as can be seen from Fig. 2, if the plane of deflection
is clearly known to begin with.
The respective l'zero sensor", which is located in the origin
of the x-y coordinate cross, i.e., in the zero point of the
y-axis, is marked 15 and 16, respectively. The scale in the
,. ,:,
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direction of the y-axis is consi~e~b~9enlarged here relative to
the length, along the "zero sensor plane" E.
The measured values of the various receivers arranged on the
two ends of the elongate component or beam are preferably added
and the result is divided by two. In this way, a good measure
for the actual deflection is obtained also in the case of an
asymmetric deflection, according to Fig. 2. Employed to that end
,,.
is a summing device 11, which may be designed also as an
averaging device. Here, the signal Y 1 = + 6, the signal
Y 2 = - 1, thus, one-half the sum is 2.5.
Thermal stresses can preferably be precluded by providing
the beam with cooling channels or heating channels, which are
provided within it or on its outside. A slight localized
distortion of the beam in the csnter area, however, where the
receiver(s) are preferably applied, is compensated for in the
measuriny result by the proposed arrangement. Resulting from
such distortions ~plate distortion) of the beam is a slanted
arrangement of the transmltter which, however, essentially leads
to equally large measuring results of opposite sign, of a faked
beam de~lection, which offset one another through the summation.
Suitable as sensor elements of the pickups 5 and 6 are
preferably light-sensitive diodes and it is recommended that the
transmitter 4, respectively 4', operate with laser light.
For the "simple" case of a symmetric deflection according to
Fig~ 1, one transmitting unit (for instance the right-hand unit 4
in Fig. 2) is frequently sufficient, and consequently also only
one receiver unit ~unit 6 in Fig. 1 or, alternatively, also
transmitting unit 4' of Fig. 2 and receiving unit 5 in Fig. 1).
For a trouble free operation, naturally, it is favorable to
arrange the signal devices within a sheet metal cover 10 attached
to the elongate component or beam 1. The one receiver circuit
-: .. . , ~. .
.: ',; , ~ .
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1 326593
~ r evaluation of the receiver signal is marked 8 while the other
receiver circuit is marked 9. The transmitters for laser light
~ are supplied by the firm Raytec AG, in Chur/Switz~rland,, 65 Rossbodenstrasse, designated as laser directional measuring
instrument. The design of support beams for coating devices can
be seen, e.g., fro U.S. Patent No. 4,512,279.
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Representative Drawing